Redo carotid endarterectomy (CEA) and carotid stenting (CAS) are often performed when there is evidence of post-procedural restenosis. The incidence of restenosis after carotid reconstruction is not negligible, ranging from 5 to 33%. The diagnosis of significant internal carotid artery (ICA) restenosis is usually based on duplex ultrasound (US) criteria, mostly on peak-systolic flow velocity (PSV). However, there have been no generally accepted duplex US criteria for carotid restenosis after CAS or CEA.In this systematic review, the PubMed/ Medline and Scopus databases were screened to find trials that reported duplex US criteria for significant restenosis after CEA and/or CAS. Only those reports were analyzed in which the restenoses were also assessed by CT/MR or digital subtraction angiography as comparators for duplex US.Fourteen studies met the predetermined search criteria and were included in this review. In most studies, PSV thresholds for significant in-stent ICA restenosis after CAS were higher than those for significant stenosis in non-procedurally treated (native) ICA. Many fewer studies investigated the US criteria for ICA restenosis after CEA. Despite the heterogeneous data, there is a consensus to use higher flow velocity thresholds for assessment of stenosis in stented ICA than in native ICA; however, there have been insufficient data about the flow velocity criteria for significant restenosis after CEA. Although the flow velocity thresholds for restenosis after CAS and CEA seem to be different, the large studies used the same duplex criteria to define restenosis after the two procedures. Moreover, different studies used different flow velocity thresholds to define ICA restenosis, leading to variable restenosis rates.We conclude that (1) further examinations are warranted to determine appropriate duplex US criteria for restenosis after CAS and CEA, (2) single duplex US parameter cannot be used to reliably determine the degree of ICA restenosis, (3) inappropriate US criteria used in large studies may have led to false restenosis rates, and (4) studies are required to determine if there is a benefit from redo carotid artery procedure, such as redo-CEA or redo-CAS, starting with prospective risk stratification studies using current best practice non-invasive care alone. Redo carotid endarterectomy (CEA) and carotid stenting (CAS) are often performed when there is evidence of post-procedural restenosis. The incidence of restenosis after carotid reconstruction is not negligible, ranging from 5 to 33%. The frequency of carotid restenosis after CAS and CEA depends on the definition and assessment criteria of restenosis and the duration of follow-up.A meta-analysis of the prevalence of stroke in asymptomatic patients with severe restenosis (>70%) after CAS showed no higher risk of ipsilateral stroke than in patients without severe in-stent restenosis. However, after a mean follow-up of 37 months after CEA, the rate of ipsilateral stroke in asymptomatic patients with severe internal carotid artery (ICA) restenosis, although low 5.2%), was higher than in patients without severe restenosis 1.5%) (.5% (1). %, was hiCarotid duplex ultrasound (US) is a popular non-invasive screening test that is used for follow-up after CEA or CAS, while computed tomography angiography (CTA) or contrast-enhanced magnetic resonance angiography (MRA) serves as an independent assessment. In most studies, restenosis rates reported after carotid artery surgery or stenting were based on duplex ultrasound findings –5. HowevIn this report, we aimed to review the literature to examine the ultrasound criteria for carotid restenosis developed after CAS or CEA. Only those reports were selected, in which duplex US criteria were examined for significant restenoses estimated by CTA, MRA, or digital subtraction angiography (DSA).A systematic review was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The PubMed/Medline and Scopus databases were independently searched by three investigators  to identify prospective or retrospective trials involving ultrasound criteria for restenosis after CEA and/or CAS. The oldest publication date of the searched articles was January 1990, while the date of the last search was 1 May 2023. Only those reports were selected for analysis, in which the ultrasound criteria were examined for at least a 50% ICA restenosis that was also estimated by CTA, MRA, or DSA. Due to the highly variable and insufficient data, quantitative analysis could not be performed.The keywords for the search were the following:carotid endarterectomy ANDrestenosis AND(duplex OR Doppler OR ultrasound) AND(criteria OR threshold OR cut-off)carotid ANDstent ANDrestenosis AND(duplex OR Doppler OR ultrasound) AND(criteria OR threshold OR cut-off)Data retrieved from each constituent trial included the type of carotid intervention , the method for determining the degree of stenosis , the presence or absence of restenosis greater than a certain degree, and the ultrasound criteria. The ultrasound criteria contained cutoff values for peak systolic flow velocity (PSV), end-diastolic flow velocity (EDV), and internal carotid artery and common carotid artery peak systolic flow velocity ratio (ICA/CCA PSV ratio).The literature search found 148 potentially relevant records after duplicates were removed. After screening titles and abstracts, 36 articles were selected for full-text evaluation. Fourteen studies met the predetermined search criteria and were included in this systematic review , 11–20, n = 8), CTA (n = 2), and DSA or CTA (n = 4). All studies used the NASCET criteria for evaluating the degree of stenosis. There was heterogeneity in the definition of significant carotid stenosis: ≥50% or ≥ 60% stenosis was used for the definition of a less severe ICA restenosis , CTA (n = 2), and DSA or CTA (n = 2). A total of 2,852 patients with previous carotid stenting were included in the studies  in-stent restenosis , 11–16, In severe ≥70%) in-stent restenosis 0% in-ste, 16–18, n = 3) evaluated the duplex criteria for post-surgery restenosis after CEA (n = 11). Moreover, AbuRahma et al. investigated the same patients in their two reports  post-surgical restenosis, the PSV cutoff value was 213 cm/s , 20, whiIn severe (≥70%) post-CEA restenosis, PSV thresholds were reported to be 274 and 220 cm/s , 19. TheIt should be emphasized, however, that due to the low number of duplex ultrasound studies investigating restenosis after CEA, no conclusions can be drawn about the ultrasound criteria for classifying post-surgical restenosis.n = 8), CTA (n = 2), and DSA or CTA (n = 4) to assess the severity of carotid restenosis and to serve as a comparator for US data. In in-stent restenosis studies, the comparator method was DSA in seven, CTA in two, and DSA or CTA also in two studies. In post-CEA restenosis trials, DSA was used in one study and DSA or CTA in two studies.As our aim was to investigate the duplex US criteria for significant carotid restenosis, we analyzed those duplex US studies that used an independent imaging modality including DSA  used for evaluation, the duplex criteria for restenosis after CAS and CEA are highly variable. The high variability of flow velocity thresholds suggests that no single duplex ultrasound parameter can be used to reliably determine the degree of ICA restenosis after CAS or CEA. Similar to the assessment of the severity of stenosis in native ICA , combinaIn the era of the first carotid endarterectomy trials, DSA was the only imaging technique to evaluate the degree of carotid stenosis. Two basic calculation methods were used to measure the percentage reduction in the luminal diameter of ICA on DSA images: the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods , 23. BotIt has to be mentioned, however, that the development and spread of non-invasive imaging techniques is increasingly displacing DSA. As the results of non-invasive methods are correlated with the findings of DSA to a variable degree , the useCurrently, there is no internationally accepted standard for grading carotid stenosis. Previously, catheter angiography was considered the gold standard for measuring the severity of carotid stenosis, but it has been replaced by non-invasive imaging techniques in the last decades, including MRA, CTA, and duplex ultrasound. It should be noted, however, that all carotid imaging techniques including DSA have limitations, and no method has an absolute advantage over the others –26. ContAs It has to be emphasized that fewer studies investigated the duplex US criteria for ICA restenosis after CEA than after CAS . SearchiUsing CTA or DSA for comparison, the PSV cutoff value for ≥50% post-CEA restenosis was 213 cm/s. Surprisingly, the PSV threshold for ≥50% restenosis (213 cm/s) was barely lower than those for ≥70% restenosis after CEA .It should be highlighted that most of the studies examined patients after CEA with patch closure , 19, 20,Although the cutoff values for significant in-stent restenosis were variable, there was a consensus to use higher flow velocity criteria for assessment of the degree of in-stent restenosis after CAS than in native ICA . Based oHigher flow velocity in in-stent restenosis after CAS may be due to changes in the biomechanical properties of the artery, including higher stiffness of the arterial wall, rendering the stented carotid artery similar to a rigid tube. This process decreases arterial compliance, leading to a reduced alteration of the volume of the arterial segment during different phases of the pulse wave .As The use of higher thresholds in post-CEA restenosis compared to native arteries was confirmed by data from Benzing et al. , who invChange of conformation of carotid bifurcation, neo-intimal hyperplasia, and vascular remodeling after carotid surgery are considered to be the most likely explanations for why the standard duplex US criteria used for stenosis of native ICA do not match the criteria for ICA restenosis after carotid surgery .As flow velocities in significant ICA restenosis after both CAS and CEA are higher than in native ICA stenosis, the use of standard duplex US criteria developed for native arteries may overestimate the degree of restenosis after CAS and CEA. Moreover, PSV threshold values after CAS seem to be higher than after CEA for estimating ≥50% and ≥ 70% restenoses. This observation is in line with the results of Lucatelly et al. who monitored ICA flow velocity changes in the 1st year after CAS and CEA and found higher flow velocities in the CAS than in the CEA group .Although the definition of restenosis in large randomized controlled restenosis trials is variable, moderate and severe carotid restenoses are mostly defined by at least 50 and 70% diameter reductions, respectively. The major prospective, randomized, multicenter trials comparing the safety of CEA versus CAS were the CAVATAS , ICSS , SPACE (Stent-Protected Angioplasty Versus Carotid Endarterectomy), EVA-3S (Endarterectomy versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis), and CREST  trials , 34–40. Due to the lack of consensus on duplex criteria for restenosis, the flow velocity thresholds for severe carotid artery restenosis were highly variable. While the PSV threshold for defining carotid artery restenosis of at least 70% was 210 cm/s in the ICSS study  and 300 Currently, there is no randomized trial data, which demonstrates a benefit of a carotid procedure compared to best practice non-invasive intervention alone in symptomatic or asymptomatic patients with carotid restenosis after CAS or CEA.In asymptomatic patients with severe in-stent restenosis receiving non-invasive treatment alone, a meta-analysis showed a very low ipsilateral stroke rate (0.8%) compared to patients without severe in-stent restenosis 2.0%) during a 50-month follow-up after primary CAS , 2. Pati.0% durinQuite the contrary, a meta-analysis revealed a higher ipsilateral stroke rate 5.2%) in non-invasively treated asymptomatic patients with severe post-CEA restenosis than in those without restenosis 1.5%) during a 37-month follow-up after primary CEA  of redo CEA and CAS. The benefits of invasive carotid interventions can only be proven if randomized controlled trials show their superiority over the current best medical intervention alone; however, these trials are missing. Furthermore, randomized procedural trials are not indicated, and are unethical, if average annual ipsilateral stroke rates are sufficiently close to zero with non-invasive care alone.Currently, there is no evidence of the benefit of either redo CEA or CAS for severe carotid restenosis, but there is data on the significant risk of periprocedural complications in invasive carotid procedures. Although we did not perform systematic analysis, we evaluated those trials and analyses from the PubMed database which reported the early periprocedural rates after redo CEA or carotid stenting for post-CEA restenosis and included more than 100 patients –56. TablUsing data from Abbott’s study for comparison , we founAs mentioned before, transfemoral carotid artery stenting (CAS) in native carotid stenosis is associated with a higher 30-day periprocedural stroke or death rate compared to CEA , 40, 58,There is evidence that non-invasive best medical intervention is highly effective in carotid stenosis. Moreover, optimal treatment of vascular risk factors decreases not only the stroke risk but also all arterial disease complications, including the risk of myocardial infarction and vascular death. Abbott showed that the benefit from non-invasive medical intervention alone in patients with carotid stenosis has improved over the last 4 decades, leading to a substantial decrease of average annual ipsilateral stroke rates below 1%/year (approximately 0.8%/year) in patients with advanced asymptomatic carotid stenosis , 62–64.Studying symptomatic patients with carotid stenosis awaiting revascularisation in recent randomized controlled trials  and in medical arms of earlier randomized controlled trials  revealed that modern non-invasive care alone halved the stroke risk compared to that of earlier studies . AvailabAlthough the “optimal medical treatment” is described in detail in the Clinical Practice Guidelines of the European Society for Vascular Surgery from 2017, none of the large restenosis studies , 38, 40 Invasive carotid artery procedures in severe carotid restenosis after CEA or CAS are currently not justified. However, despite the lack of evidence for the benefit of CAS or CEA compared to the best non-invasive care alone, current guidelines endorse invasive procedures for severe carotid restenosis that is defined by PSV thresholds of 274 and 300 cm/s after CEA and CAS, respectively , 24, 69.The current priority is to measure the average annual ipsilateral stroke rate in symptomatic and asymptomatic patients with severe carotid restenosis after CEA or CAS treated with the current best non-invasive medical care alone. A subgroup of patients with a sufficiently high risk of ipsilateral stroke despite the best non-invasive medical treatment (≈3%) should be considered for future randomized trials to answer whether redo CEA or CAS provides an additional stroke risk reduction compared to the best non-invasive medical treatment alone. Therefore, routine invasive carotid procedures should be stopped in patients with ICA restenosis after CAS or CEA in order to begin observational studies with long-term follow-up (at least 3–4 years) and to stratify the risk of ipsilateral stroke in patient subgroups with different restenosis severity. Although we focused on carotid restenosis in this report, the constant and significant improvement of non-invasive treatment alone and the outdated results of randomized carotid stenosis trials performed 3–4 decades ago , 24, 69 As risk stratification of ipsilateral stroke in patients with different restenosis severity is essential, reliable diagnostic criteria for significant carotid restenosis after CAS and CEA must be clarified. Being non-invasive, harmless, and easily available, duplex US could be the first-line tool for monitoring carotid restenosis. However, the lack of consensus on flow velocity thresholds for carotid restenosis requires new diagnostic studies. The comparison of complex US data  with the degree of restenosis assessed by angiographic methods may answer which duplex US criteria predict best the ≥50% and ≥ 70% carotid restenosis after CAS and CEA and whether these duplex US criteria are different in post-CEA and in-stent restenosis.The accurate evaluation of carotid restenosis is essential to diagnose significant carotid restenosis and to determine and compare the real restenosis rates in different carotid procedure trials. Due to the lack of consensus on duplex US criteria for carotid restenosis, further examination is warranted to find complex ultrasound criteria suitable for identifying significant ICA restenosis after invasive carotid artery procedures. However, it should be highlighted that a meaningful definition of clinically significant carotid restenosis that determines the management approach to best reduce the risk of ipsilateral stroke depends on the associated risk of stroke with the current best standards of non-invasive care alone and, subsequently, any benefit from a redo carotid procedure in addition to current best non-invasive medical care.Our manuscript demonstrates the lack of reliable data on annual ipsilateral stroke rate in patients with severe carotid restenosis treated with current best non-invasive medical care alone, which is essential to identify a subgroup of patients with high risk of ipsilateral stroke. This could open the way for new randomized trials to determine whether redo CEA or CAS provides an additional stroke risk reduction compared to the best non-invasive medical treatment alone in this subgroup. Due to the significant periprocedural complication rate of invasive carotid artery procedures in severe carotid restenosis and the low and continuously decreasing ipsilateral stroke risk with best medical intervention alone, choosing to use current best practice non-invasive care alone is recommended until there is clear evidence that adding a carotid artery procedure improves patient outcomes.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.IS, FP, and ZRM systematically screened the literature and extracted the data. IS, CD, and LO processed the articles. IS, LC, and LO wrote the article. All authors have read and agreed to the published version of the article.


In atrial fibrillation (AF) patients, presence of expiratory airflow limitation may negatively impact treatment outcomes. AF patients are not routinely screened for expiratory airflow limitation, but existing examinations can help identify at-risk individuals. We aimed to assess the diagnostic value of repurposing existing assessments from the pre-ablation work-up to identify and understand the characteristics of affected patients.We screened 110 consecutive AF patients scheduled for catheter ablation with handheld spirometry. Routine pre-ablation work-up included cardiac computed tomographic angiography (CCTA), transthoracic echocardiography and polygraphy. CCTA was analyzed qualitatively for emphysema and airway abnormalities. Multivariate logistic regression analysis was performed to determine predictors of expiratory airflow limitation.We found that 25 % of patients had expiratory airflow limitation, which was undiagnosed in 86 % of these patients. These patients were more likely to have pulmonary abnormalities on CCTA, including emphysema  and bronchial wall thickening . The absence of pulmonary abnormalities on CCTA accurately distinguished patients with normal lung function from those with airflow limitation . Echocardiography and polygraphy did not contribute significantly to identifying airflow limitation.In conclusion, routine pre-ablation CCTA can detect pulmonary abnormalities in AF patients with airflow limitation, guiding further pulmonary assessment. Future studies should investigate its impact on ablation procedure success. In this context, all consecutive patients with symptomatic paroxysmal or persistent AF that completed the full pre-ablation work-up between August 2021 and March 2022 were prospectively enrolled in this study. AF was confirmed by at least one 12-lead electrocardiography (ECG) documentation in accordance with the ESC guidelines 2.215.Demographic and anthropometric data were collected at baseline during the first outpatient clinic visit. Medical history and associated treatment were retrieved from medical records. AF symptom burden was assessed with the European Heart Rhythm Association (EHRA) score, the Toronto AF severity scale questionnaire (AFSS) and the AF quality of life survey (AFEQT) 2.36) to forced vital capacity (FVC) ratio of 0.73 or less 1) to FVC ratio of 0.70 or lower In this study, two handheld spirometry devices were used to evaluate pulmonary function, either the Vitalograph COPD-6  or AioCare® . In accordance with the European Respiratory Society guidelines, we defined expiratory airflow limitation as a pathological reduction in airflow from the lungs that leads to a reduced FEV1/FVC ratio 2.4CCTAs were performed using a third-generation dual-source CT scanner . Initially, a non-contrast enhanced scan was performed to evaluate the degree of coronary artery calcification  or ANOVA (three groups comparison) in the case of parametric variables and Mann–Whitney U test (two-group comparison) or Kruskal–Wallis test (three groups comparison) in the case of non-parametric variables.All continuous variables were tested for normality with the Kolmogorov-Smirnov test and visual interpretation. Variables with normal distribution are expressed as mean ± standard deviation (SD) and non-parametric variables are expressed as median and interquartile range (IQR). Categorical data are presented as counts (n) with percentages (%). Fisher’s exact test (two groups) or χ2 test (three or more group comparisons) were used to compare categorical variables. Differences in continuous parameters were compared with unpaired To test the diagnostic value of routinely available studies from cardiac analysis, a multivariate logistic regression analysis with backward stepwise elimination was performed for all variables that reached significance in univariate analysis. Accuracy was expressed as sensitivity, specificity, and positive and negative predictive values of each diagnostic study . The area under the curve (AUC) of receiver operating characteristic curves was assessed for each variable. A two-sided P value of 0.05 was considered statistically significant. Castor EDC  and IBM SPSS Version 28  were used for database management and statistical analysis.33.1A total of 110 consecutive patients scheduled for AF ablation were included in this study . The baseline characteristics of the study population are presented in 3.2We found 24 patients with newly diagnosed expiratory airflow limitation and for an additional 4 patients a previous diagnosis was confirmed  than in patients with normal lung function . No difference in RVSP was found between patients with expiratory airflow limitation versus patients with normal lung function  compared to patients with a normal lung function.Hypertension was more often prevalent in patients with expiratory airflow limitation compared to patients with normal lung function . The likelihood of expiratory airflow limitation was higher in patients with hypertension  and in patients with higher thromboembolic risk  to differentiate patients with normal lung function from those with expiratory airflow limitation. However, the sensitivity of CCTA to detect expiratory airflow limitation was lower. This can be attributed to two factors, namely, the predilection site for centrilobular emphysema in the apical lung fields, which is not adequately captured in the limited pulmonary view provided by CCTA, and the limited involvement of lung parenchyma in patients with asthma Regarding the other available resources of the pre-ablation work-up, echocardiography was insufficient to detect patients with expiratory airflow limitation. The RVSP, the echocardiographic estimation of pulmonary hypertension, may be elevated in patients with severe chronic lung disease due to hypoxic pulmonary vasoconstriction One unanticipated finding of the present study was that the nocturnal hypoxemic burden was less severe in patients with expiratory airflow limitation. This rather paradoxical result may be because patients with expiratory airflow limitation, specifically COPD, have less collapsible airways due to air trapping. This has been previously described in COPD patients In this study, systematic lung function testing revealed previously undiagnosed expiratory airflow limitation in a substantial proportion (22 %) of patients undergoing AF catheter ablation. The prevalence of expiratory airflow limitation is higher than previously reported numbers from pooled data No correlation was found between expiratory airflow limitation and symptom severity questionnaires for AF, COPD or sleep apnea. These findings indicate that relying solely on disease-specific questionnaires to assess symptoms may not be enough to rule out the presence of co-existing expiratory airflow limitation in patients with AF. Similar limitations are observed when using these questionnaires for other pulmonary comorbidities in AF patients, such as sleep apnea We acknowledge the variability in standard diagnostic practices, which may not be universal in all centers. However, our research underscores the potential of emerging techniques and the need for optimization. We aim to streamline pre-ablation work-ups based on available resources to enhance overall AF management. Our findings on a COPD screening and management pathway suggest that embedding such pathways, utilizing (micro)spirometry and remote result analysis, is feasible within an existing AF outpatient clinic infrastructure 4.1While the study is limited by a small sample size and the absence of a control group, the external validity of the study is considered satisfactory because the overall cohort exhibits representative baseline characteristics. However, the absence of a control group leaves the potential benefits of pulmonary screening on the success of the ablation procedure uncertain. Secondly, our study involved the use of two different spirometry devices. Although this choice is unlikely to have significantly influenced the core evaluation of expiratory airflow limitation, it may have had an impact on the comparability of severity levels between these devices. Additionaly, we only performed pre-bronchodilator measurements, which may not be sufficient for confirming COPD or asthma diagnoses, as post-bronchodilator measurements are required. Moreover, unpublished observations highlighted differences in accuracy between the devices, specifically noting the low sensitivity of the COPD-6 device 4.2In conclusion, patients with expiratory airflow limitation more often present with CCTA-derived pulmonary abnormalities. This knowledge presents an opportunity to repurpose existing resources from the pre-ablation work-up, aiding in the pre-selection process of AF patients who need formal lung function screening. The clinical performance and the potential benefits on the success of the ablation procedure needs to be investigated in future studies.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: .


Catheter ablation of ventricular arrhythmias has evolved considerably since it was first described more than 3 decades ago. Advancements in understanding the underlying substrate, utilizing pre-procedural imaging, and evolving ablation techniques have improved the outcomes of catheter ablation. Ensuring safety and efficacy during catheter ablation requires adequate planning, including analysis of the 12 lead ECG and appropriate pre-procedural imaging. Defining the underlying arrhythmogenic substrate and disease eitology allow for the developed of tailored ablation strategies, especially for patients with non-ischemic cardiomyopathies. During ablation, the type of anesthesia can affect VT induction, the quality of the electro-anatomic map, and the stability of the catheter during ablation. For high risk patients, appropriate selection of hemodynamic support can increase the success of VT ablation. For patients in whom VT is hemodynamically unstable or difficult to induce, substrate modification strategies can aid in safe and successful ablation. Recently, there has been an several advancements in substrate mapping strategies that can be used to identify and differentiate local late potentials. The incorporation of high-definition mapping and contact-sense technologies have both had incremental benefits on the success of ablation procedures. It is crucial to harness newer technology and ablation strategies with the highest level of peri-procedural safety to achieve optimal long-term outcomes in patients undergoing VT ablation. Catheter ablation has an important role in the management of patients with ventricular tachycardia (VT) , 2. AdvaA careful evaluation of the patient history, 12 lead ECG, and imaging are critical for understanding the mechanism and localization of the origin of VT. Anatomic substrate, electrophysiological characteristics and approach to catheter ablation are different among patients with ischemic and non-ischemic cardiomyopathies. While the scar in ischemic cardiomyopathy is usually sub-endocardial, patients with non-ischemic cardiomyopathy (NICM) often have patchy VT circuits located in mid-myocardium and epicardial location , 4. Pati2 away from the critical isthmus  can help characterize the site and extent of the underlying scar. Presence of q waves in sinus rhythm can provide a clue regarding the location of myocardial scarring. In patients with NICM, fragmented QRS complexes can be used to aid scar localization . The 12  isthmus . Clinica isthmus , 12. Sev isthmus , 14. Irr isthmus . Electro isthmus .Pre-procedural imaging can be very useful in guiding the operator towards the areas of interest and increasing success rate of ablation. Contrast enhanced MRI (CMR) has become the cornerstone of pre-procedural imaging because of its ability to delineate myocardial scar , 18. In Computed tomography is a viable option when MRI is not feasible. It has higher spatial resolution than CMR and its use is increasing as a pre-procedural tool during VT ablation . HoweverIn patients with acute inflammatory cardiomyopathies, a fluorodeoxyglucose-positron emission tomography (FDG-PET) scan have an incremental advantage in diagnosis and assessing the extent of inflammatory burden. In patients with inflammatory cardiomyopathies like sarcoidosis, the results of CA during the inflammatory phase are poor and the recurrence rates were higher . CombiniLastly, cardiac computed tomography (CT) can also provide an accurate roadmap of anatomy and to minimize complications. Major collateral injury to adjacent structures like the heart, liver and coronary vessels have been reported in 4%–10% of patients during subxiphoid percutaneous epicardial access , 35. We Vascular complications due to access site issues are to be strictly avoided. Complications are due to multiple large-bore access sites followed by intra-procedural systemic anticoagulation. Ultrasound guidance has been shown to improve the safety by reducing vascular access-related complications . UltrasoDiscussions between the electrophysiologist and anesthesiologist prior to procedure can be extremely useful in helpful in increasing the success rate of CA and mitigating complications. Depending on the patient and the operator, VT ablation is usually performed under general anesthesia or under monitored anesthesia care (MAC). Advantages of MAC with sedation are avoiding anesthetics that can potentially depress myocardial contractility and decrease the inducibility of VT . IdiopatIn recent years, mechanical circulatory support has be used as both an emergent “rescue” and prophylactic therapy for high-risk patients undergoing VT ablation. Acute hemodynamic compromise can occur not only during sustained VT, but also during sinus rhythm or right ventricular pacing. The PAAINESD score is a risk stratification tool that has been used to guide selection of patients for mechanical circulatory support (MCS) . The advIntra-procedural imaging for VT ablation involves two major aspects—image integration into the electro-anatomic mapping (EAM) system and real-time imaging during ablation. Integrating CMR images with EAM can enhance the scar definition and has the potential to facilitate targeted approaches to VT ablation. When patients undergoing MRI-derived scar-guided ablation were compared to those undergoing traditional ablation, there is a lower incidence of recurrence in the former , 42. IntAnticoagulation strategies during VT ablation are dependent on right vs. left sided ablation and whether the patient was already using a vitamin K antagonist or direct oral anticoagulant prior to the procedure. During ablation of left sided VT, therapeutic anticoagulation is crucial and special considerations are needed depending on the LV access route. During LV endocardial ablations, full dose heparin is generally given once trans-septal access is achieved. An initial bolus of 100 U/kg followed by intermittent boluses or continuous infusion of heparin to main an ACT >300s is ideal . It is iFor patients with VTs that are difficult to induce or hemodynamically unstable, activation and entrainment mapping cannot be performed. Substrate-mapping strategies have a crucial role and are required for successful VT ablation. Most VT exit sites are in the periphery of the scar , while the critical isthmus resides within the dense scar. In the endocardium, bipolar peak-to-peak voltage definitions are used to describe preserved tissue (>1.5 mV), borderzone tissue (0.5–1.5 mV) and dense scar (<0.5 mV) . The limFractionated electrograms are considered indicative of preserved myocardial fibers interspersed within a fibrous scar tissue. The heterogeneities in the cellular electric properties and local tissue architecture create regions of discontinuous slow conduction . Due to Late potentials are characterized by low amplitude, usually fractionated signals, with a bipolar amplitude <1.5 mV. They are detected after the local ventricular electrogram and QRS. These late potentials originate from slow-conducting surviving bundles of myocardium in areas of fibrotic scar tissue . IsolateHowever, some sites yielding late potentials during sinus rhythm can be bystander sites during VT, despite being areas of slow conduction. Late potential mapping can have a very low sensitivity and moderate specificity for VT channels, especially in patients with a large scar burden. The presence of multipotential electrograms, long stimulus-QRS intervals during pace mapping, and the presence of late potentials inside voltage channels can increase the specificity of late potentials . Hence iSubstrate-based mapping strategies that target only late potentials may miss critical arrhythmogenic substrates, especially in early activating regions such as the septum. A source-sink mismatch or fibrotic barrier between up and downstream elements can produce a functional block within the scar . One of Reduced cell-to-cell coupling due to altered distribution of gap junction proteins can contribute to slowing or conduction block at faster rates. This regional heterogeneity can be unmasked by programmed ventricular extra-stimulus pacing. This kind of pacing can potentially identify late potentials within scar or at scar border zones that are likely to participate in the initiation and maintenance of VT. Decremental evoked potentials (DEEPs) mapping utilizes a specific S1–S2 protocol to deliver extrastimulus mapping from the right ventricle. DEEP mapping has been found to be more specific than late potential mapping for identifying critical targets with in the diastolic pathway of VT .Another strategy described by Di Biase and colleagues is scar homogenization. This usually involves ablation of the entire scar, with particular focus on late fractionated signals in the scar tissue . In thisCurrent substrate-based ablation strategies emphasize the need for high density mapping to identify and target all multicomponent electrograms. High density multi-electrode mapping has brought about a paradigm shift in substrate characterization during VT ablation. Local electrogram voltages are dependent on the recording electrode size, inter-electrode spacing, and direction of wavefront propagation . The usePace-mapping within scar can identify slow conduction areas by a long-stimulus to QRS interval latencies (>40 ms), that can correlated with VT isthmus sites . HoweverNon-inducibility of the clinical tachycardia is a major limitation while attempting to map and ablate VT. Earlier reports indicate difficulty in induction of VT in approximately 25%–40% of patients of idiopathic left ventricular tachycardia . Using aN + 1 technique difference allows entrainment mapping to be used when the local electrogram from the pacing catheter has artefacts after high output pacing  , 85. DurIn a certain subset of patients, especially those with mid-myocardial substrates, there is a growing need to develop new strategies for deeper lesion formation. Alternatives such as half-normal saline and dextrose solution are able to create larger lesions compared to saline irrigation . ModulatUtilizing two catheters for either simultaneous unipolar ablation or bipolar ablation can be used to achieve transmural lesions. Bipolar ablation uses two catheters connected to the radiofrequency generator , placed on opposite surfaces of the myocardial tissues. This can also be achieved with simultaneous unipolar ablation with 2 catheters connected to separate radiofrequency generators. Observational case series have found these techniques to useful to terminate VT in patients who unsuccessful unipolar ablation of septal substrates  Figure . RecentlIdentification of the optimal endpoints for VT ablation is crucial to improve the success rate of this procedure. The response to programmed electric stimulation at the end of the procedure has been traditionally used to evaluate not only the acute success but also to predict the long term outcome. The guidelines endorse noninducibility of PES as an endpoint for VT ablation . HoweverRegarding substrate-based ablation approaches, there is an increasing need for novel endpoints beyond non-inducibility to evaluate the completeness of linear lesions and the elimination of abnormal electrograms. Studies that have assessed the role of late potential ablation in scar related VT have adopted procedural endpoints ranging from complete elimination of late potentials to failure to capture with high output pacing. Berruezo and colleagues also used elimination of all conductive channels and found that this method resulted in a very high rate of VT-free survival during median follow up of 11 months . A box lThere are limited data regarding the effectiveness and safety of post-ablation anticoagulation strategies after VT ablation. In the post op period, the benefits of anticoagulation need to be weighed against the risks of bleeding. Siontis and colleagues found that using a slowly escalating bridging regiment of UFH, followed by 3 months of oral anticoagulation is associated with low thromboembolic and bleeding risk after infract-related VT ablation . In the Safety and efficacy of catheter ablation for ventricular tachycardia has steadily improved. Better understanding of the pathophysiology of VT, advanced mapping systems as well as development of contact force sensing catheters have resulted in improved outcomes. Substrate modification strategies helps to safely and successfully ablate VTs in sick cohort of patients, as it eliminates the need for repeated induction of VT for mapping. Most importantly, utilizing a systematic approach to mapping and ablation of VT is crucial for management of these patients and improving overall clinical outcome.


Although pulmonary artery catheter (PAC) has been used during liver transplantation surgery, the usefulness of PAC has rarely been investigated. We evaluated whether the use of PAC is associated with better clinical outcomes compared to arterial waveform-based monitoring after liver transplantation. A total of 1565 cases undergoing liver transplantation were reviewed. We determined whether patients received PAC or not and divided our cohort into the PAC with hemodynamic monitoring using PAC and the non-PAC with arterial waveform-based monitoring using FloTrac-Vigileo. Propensity score matching was performed. Acute kidney injury (AKI), early allograft dysfunction (EAD) and 1-year all-cause mortality or graft failure were compared in the matched cohorts. Logistic regression analysis was performed in the inverse probability of treatment-weighted (IPTW) cohort for postoperative EAD and AKI, respectively. Five-year overall survival was compared between the two groups. In the matched cohort, there was no significant difference in the incidence of AKI, EAD, length of hospital or ICU stay, and 1-year all-cause mortality between the groups. In the IPTW cohort, the use of PAC was not a significant predictor for AKI or EAD  of 1.20 (0.47–1.56), p = 0.229; EAD: 0.99 (0.38–1.14), p = 0.323). There was no significant difference in the survival between groups after propensity score matching (Log-rank test p = 0.578). In conclusion, posttransplant clinical outcomes were not significantly different between the groups with and without PAC. Anesthetic management without the use of PAC may be possible in low-risk patients during liver transplantation. The risk should be carefully assessed by considering MELD scores, ischemic time, surgical history, previous treatment of underlying liver disease, and degree of portal and pulmonary hypertension.Registration: https://clinicaltrials.gov/ct2/show/NCT05457114 . PAC is connected to a continuous cardiac output monitor  and could provide continuous pulmonary artery pressure, and hemodynamic parameters of mixed venous oxygen saturation (SvO2), right ventricular end-diastolic volume, as well as continuous cardiac output. Baseline coagulopathy, portopulmonary hypertension, procedural difficulty of vascular anastomosis, clamping of inferior vena cava and graft reperfusion during liver transplantation frequently result in hemodynamic instability and massive bleeding, which necessitates advanced hemodynamic monitoring with PAC.Pulmonary artery catheter (PAC) has been used for advanced hemodynamic monitoring during liver transplantation2. Using this technology, stroke volume variation is monitored as a preload index and its value was reported during liver transplantation3. Calculated systemic vascular resistance can be monitored if central venous pressure is provided. Although this arterial waveform-based hemodynamic monitoring may replace the PAC, PAC is still frequently used in United States academic centers1.However, recent advances in arterial waveform-based monitoring can provide continuous cardiac output monitoring by arterial waveform analysis5. They reported mixed results of no difference or increased mortality and end-organ complications in the group with PAC. Although these studies enrolled high-risk urgent or elective cardiac or non-cardiac surgery, clinical trials involving the patients undergoing liver transplantation have not been performed. Only small retrospective observational studies are found for liver transplantation7. These studies reported no association of PAC use with postoperative clinical outcomes including graft failure3. Another retrospective analysis reported that PAC monitoring combined with intraoperative transesophageal echocardiography (TEE) monitoring could reduce 30-day all-cause mortality. However, these studies were from a small sample size, and perioperative parameters that potentially affect mortality or graft failure were not fully adjusted in their statistical analysis.There have been several clinical trials that investigated the clinical impact of PAC by comparing the cases for whom PAC was not used9. In patients undergoing living donor liver transplantation, the incidence of postoperative AKI ranged from 21 to 68%10. AKI after liver transplantation was associated with an increased 30-day mortality of 29% to 50%11, which further increases to 55 to 90% when renal replacement therapy is required12. High MELD score is a risk factor of AKI and the impact of AKI on graft and patient survival may be greater in patients with a high MELD score13.Acute kidney injury (AKI) is one of the highly prevalent complications in the perioperative settingTherefore, we attempted to add more robust evidence by performing a large retrospective cohort study. In this large retrospective observational study, we sought to compare the incidence of AKI and other clinical outcomes after liver transplantation between pulmonary artery catheter-based invasive monitoring and arterial waveform-based monitoring. We sought to evaluate whether the use of PAC is associated with better clinical outcomes compared to arterial waveform-based monitoring such as FloTrac Vigileo. For vigorous adjustment of confounding factors, we used the propensity score analysis.https://clinicaltrials.gov/ct2/show/NCT05457114 . We received a waiver of written informed consent from the Seoul National University Hospital Institutional Review Board, considering the retrospective nature of our study. All methods were performed following the relevant guidelines and regulations.We obtained approval from the Seoul National University Hospital Institutional Review Board for this retrospective observational study (H-2205-117-1327). Our study was registered before data collection and statistical analysis on Our institutional electronic patient database of 1970 consecutive adult patients who underwent living or deceased donor liver transplantation at our tertiary care university hospital between 2006 and 2022 was reviewed. The patients with baseline renal dysfunction (n = 111), missing other baseline or outcome variables (n = 142), retransplantation (n = 22) and contraindication to PAC insertion (n = 5) were excluded. Those who received intraoperative TEE monitoring (n = 125) were also excluded because the patients without PAC were mixed with arterial waveform-based cardiac output monitoring with or without TEE , length of hospital stay, in-hospital all-cause mortality or graft failure, 1-year all-cause mortality or graft failure, and postoperative hemodialysis were collected.We extracted baseline characteristics or perioperative data reported to be associated with clinical outcomes including early allograft dysfunction (EAD) and acute kidney injury (AKI) after liver transplantation Table 13–18. Po20. The most recent serum creatinine level measured before surgery was collected as a baseline value.The primary outcome of our study was AKI diagnosed by the KDIGO criteria, which was defined according to the greatest change in serum creatinine level during the postoperative seven days 18. Surgical complication rates including graft dysfunctions, vascular complications, biliary complications, and wound infection were compared by Clavien-Dindo classification21. PAC insertion-related complications including ventricular arrhythmia, right bundle branch block, complete heart block, guidewire embolism, catheter knotting, and failure to insert into the pulmonary artery were collected.Early allograft dysfunction was defined when one or more of the following are present: total bilirubin ≥ 10 mg/dL, prothrombin time: international normalized ratio ≥ 1.6 on the seventh postoperative day, or aspartate or alanine transaminase > 2000 IU/L within the first 7 postoperative days2, right ventricular end-diastolic volume, and continuous cardiac output were monitored for hemodynamic management. A decision to insert PAC was made individually at the discretion of attending anesthesiologists during the study period. PAC was not inserted simply because the patient had a high Models for End-stage Liver Disease (MELD) score. PAC was not inserted for the following contraindications of PAC insertion—right-sided endocarditis, right heart mass, tricuspid or pulmonic valvular stenosis or vegetation or other pathology and under the following circumstances—(1) development of severe arrhythmia or repeated kinking of the catheter, or (2) failure of the catheter to proceed to the pulmonary artery. The patients who had these contraindications were excluded from our analysis because the cardiac conditions could affect the clinical outcomes after liver transplantation.The primary exposure variable of our interest was the PAC  insertion for hemodynamic monitoring during liver transplantation surgery. PAC was connected to a continuous cardiac output monitor . Continuous pulmonary artery pressure, SvO23. Stroke volume, stroke volume variation, and systemic vascular resistance were also monitored by the FloTrac Vigileo system. If intraoperative TEE was monitored, the case was excluded from our analysis because we attempted to compare the hemodynamic management according to the hemodynamic parameters by PAC and arterial waveform analysis.For our statistical analysis, we divided our retrospective cohort into PAC and non-PAC groups. In the PAC group, PAC was inserted, and PAC-derived hemodynamic parameters were monitored. In the non-PAC group, arterial waveform-based monitoring with FloTrac Vigileo system  was performed for continuous cardiac output monitoringU test and incidence data were compared by or chi-square test or Fisher’s exact test depending on their expected counts. Baseline or outcome data were missing in 7.4% of records. We excluded these missing cases before our analysis. The missing was considered random, and we could not find any significant difference in the available baseline characteristics between the excluded and included cases in our preliminary analysis.We assessed the normality of our continuous data using the Shapiro–Wilk test. Continuous data were presented as the median (25 and 75 percentiles) and incidence data were reported as numbers (%). Continuous data were compared between groups by the Mann–Whitney https://doi.org/10.6084/m9.figshare.20334984.v1) . During our analysis process, we determined to omit the binary multivariable logistic regression analysis to evaluate the association of the use of PAC with the risk of EAD and AKI because there are too many analytic methods in our plan which increases the type 1 error by multiple testing.The following is the summary of our main analysis. All analyses were performed based on an a priori statistical analysis plan unless they were indicated as post hoc analysis. We published our prespecified statistical analysis plan on the following internet site  and warm ischemic time (WIT), intraoperative mean blood glucose, the amount of intraoperative hydroxyethyl starch or albumin administration, the amount of intraoperative transfusion, intraoperative estimated blood loss. These covariates were selected according to the previous studies reporting the risk factors of AKI26 or EAD28. We set the caliper width as 0.2 standard deviations of the logit-transformed propensity score. The ratio of matching between the PAC and non-PAC was 1:1 and 240 paired sets of patients were generated. We defined that baseline variables are different if the absolute standardized difference > 0.30429. Then we compared the incidence of intraoperative events including postreperfusion syndrome (PRS)30 and postoperative clinical outcomes including EAD, AKI between the matched groups.Firstly, a propensity-score matching analysis was conducted to further adjust the possible confounding effect of our independent parameters of the baseline characteristics and surgical and anesthesia-associated parameters31. This was to evaluate the robustness of our propensity score matching analysis and to avoid the power reduction by propensity score matching. During propensity score matching, a substantial number of cases are excluded due to the inability to find an appropriate match which limits the generalizability and interpretability of analysis results. IPTW incorporates the entire study population and weights the cases according to the inverse of the probability of receiving the use of PAC in order to generate a balanced pseudo population. It is also easy to show balance on baseline parameters after weighting. We used Brant’s Wald test and the likelihood ratio test to investigate the proportional odds assumption. To meet the positivity assumption of IPTW analysis, we excluded the cases with a probability of receiving PAC of 1 or 0 from our analyses. Additionally, we replaced extreme weights greater than the 99th percentile or less than the lowest first with the value of 99th or the first percentile, by weight trimming.Secondly, for another propensity score analysis, we performed a multivariable logistic regression analysis using inverse probability of treatment-weighting (IPTW) for postoperative EAD and AKI, separatelyThirdly, Kaplan–Meier survival curve analysis for the overall or graft survival was conducted between the non-PAC and PAC during the first postoperative year. We used the log-rank test to evaluate the survival difference between the two groups.Fourthly, as a post-hoc analysis to address the time-dependent bias due to the long period of our cohort, we analyzed the subgroup of our retrospective cohort from the year 2016 to 2022 (n = 675). Multivariable logistic regression analysis and propensity score analyses including matching and IPTW analysis were performed in this subgroup. The year 2016 to 2022 was chosen because 75.7% of the non-PAC cases were in this period. Before the year 2016, the number of cases managed without a PAC was very small and both strategies were consistently employed only after the year 2016.Finally, to address whether the association of PAC monitoring with clinical outcomes is different across to the different risks of patients, we performed stratified subgroup analyses according to MELD score, WIT and CIT. We stratified the high and low-risk subgroups according to the cutoffs of the highest quartile and lower three quartiles of MELD, WIT and CIT. Then we compared the incidence of EAD, AKI and other clinical outcomes between the groups.All P values are calculated for two-tailed hypothesis testing, and the significance level of 0.005 was used for statistical significance given the multiple testing for our secondary outcomes. We used Stata 15.1  for statistical analyses and Medcalc Statistical Software version 18.6  to draw the Kaplan–Meier survival curve.Among our dataset of 1565 liver transplant cases, 1339 patients received PAC insertion and hemodynamic monitoring by PAC-derived parameters. The remaining 226 patients did not receive PAC insertion and were monitored with FloTrac Vigileo  and that of EAD was 2.9% (n = 45). Supplemental Table IPTW yielded the cohort of PAC (n = 786) and non-PAC (n = 779). Supplemental Table The results of Kaplan–Meier survival curve analyses before and after propensity score matching between the PAC and non-PAC are shown in Fig. Supplemental Table Supplemental Tables In patients undergoing liver transplantation, there was no significant difference in our primary outcome of AKI as well as all other secondary outcomes including EAD and 1-year all-cause mortality or graft failure regardless of the use of PAC monitoring. To adjust possible confounding factors of baseline characteristics and perioperative parameters that potentially affect the risk of clinical outcomes, we performed propensity score matching and logistic regression analysis in the inverse probability treatment-weighted cohort. Our results suggest that PAC monitoring does not affect clinical outcomes including graft function. However, our stratified subgroups analysis for high and low MELD scores and ischemic times showed significant differences in the incidence of PRS and AKI in the subgroup of high MELD scores or high CIT. Therefore, hemodynamic management during liver transplantation without the use of PAC may be possible for patients with low MELD scores and short ischemic time.Liver transplantation requires a long operation time and is often associated with a significant amount of surgical bleeding. It is common for the anesthesiologist to infuse large amounts of fluid or blood products due to massive bleeding, hemodynamic instability, or ascites drainage.2 has been used. Among the PAC-derived hemodynamic parameters, right ventricle end-diastolic volume and SvO2 are monitored to guide intravascular volume status. Although FloTrac Vigileo monitoring provides continuous cardiac output and stroke volume variation as an indicator of fluid responsiveness and preload, some may argue that SvO2 and cardiac output measured by thermodilution technique would be more accurate compared to the arterial waveform analysis.Therefore, in the anesthesia for liver transplantation, careful and detailed hemodynamic management is required and advanced hemodynamic monitoring such as cardiac output and SvO4. They found no clinical benefit from using PAC and only the incidence of pulmonary thromboembolism was significantly higher in the group with PAC4. Another clinical trial for the patients undergoing coronary artery bypass reported increased mortality and end-organ complications in the group with PAC5.Previous clinical trials that investigated the impact of the use of PAC on the clinical outcomes enrolled patients undergoing high-risk urgent or elective surgery other than liver transplantation7. The use of PAC compared to the arterial waveform-based monitoring of FloTrac Vigileo was not associated with any difference in the duration of postoperative ventilator care, the incidence of graft failure, or length of hospital stay6. Nonetheless, the limitation of FloTrac Vigileo should be acknowledged. Arterial pulse waveform analysis by FloTrac Vigileo could be incorrect under severe vasoconstriction by use of vasopressors in these cases with massive bleeding and low temperature. Another retrospective study compared clinical outcomes between one group with PAC, another group with TEE monitoring, and the other group with both PAC and TEE monitoring. The length of hospital stay was shorter, and 30-day all-cause mortality was significantly lower in the group with both PAC and TEE monitoring. However, these studies were with small sample size and adjustment for the confounding parameters was not sufficient.However, there are only small retrospective observational studies for liver transplantation33. Intraoperative TEE could provide the status of cardiac contractility, wall motion abnormality, and preload as well as elevated right heart pressure. Cardiac output can be calculated by Doppler measurements. As intraoperative TEE can also detect catastrophic hemodynamic events such as air embolism and pulmonary thromboembolism in addition to left ventricular outflow tract obstruction, TEE could replace PAC-derived hemodynamic monitoring. However, as learning to perform TEE takes time34, the skills necessary to use TEE should be well acquired before arterial waveform-based monitoring by FloTrac Vigileo can be considered in the selective low-risk patients and TEE could be a backup strategy for arterial waveform-based monitoring.Furthermore, TEE gained growing popularity for intraoperative hemodynamic monitoring during liver transplantationAlthough our institution started intraoperative TEE monitoring about a year ago, we could not compare TEE monitoring and PAC use because most of the intraoperative TEE monitoring was used in combination with PAC use in our cohort. We excluded the patients with TEE monitoring to compare the pure association of PAC with that of arterial waveform-based monitoring.35. Although the statements were based on small retrospective observational studies, they strongly recommended PAC monitoring, particularly in cases with portopulmonary hypertension, hemodynamic instability, and cardiac dysfunction. However, as demonstrated by our study results, PAC monitoring may not be necessary for elective liver transplantation cases without portopulmonary hypertension or cardiac dysfunction associated with cirrhotic cardiomyopathy. Although hemodynamic instability develops during graft reperfusion, it is often transient and only a small dose of vasopressor or epinephrine is sufficient even for the case of PRS.Recently, expert panel recommendations were published regarding optimal anesthetic monitoring during liver transplantation36. Therefore, a necessity for advanced hemodynamic monitoring could be different according to MELD score. We found several significant differences in the incidence of PRS and AKI in the subgroup of high MELD score or high CIT, which may mean that PAC monitoring could make a difference in the clinical outcomes compared to non-PAC monitoring. Arterial waveform-based monitoring could be suggested only to the patients with low-risk patients with low MELD scores or low CIT.We performed stratified analyses to evaluate whether the association of PAC monitoring with clinical outcomes differs according to the baseline risk of the patients in terms of MELD score, CIT and WIT. Compared to low MELD patients, high MELD patients tend to already have renal insufficiency or severe coagulopathy, which makes high MELD patients more vulnerable to hemodynamic instability, fluid shifting, and metabolic acidosis39. Further studies should consider these new definitions of EAD.Our study has several important limitations. Firstly, although we performed propensity score analysis with rigorous adjustment of covariates, our study was a single-center retrospective observational study. Propensity score matching and IPTW only reduce but do not exclude the selection bias. An unmeasured or unknown confounding factor may affect our analysis results. Some may have concerns that non-PAC monitoring was chosen only in easier cases and the patients who received TEE monitoring were excluded due to the complexity of cases. However, we excluded the patients with TEE monitoring to compare PAC with Flo-Trac Vigileo monitoring, and TEE was used as a full-time monitoring from anesthesia induction, not as a rescue monitoring. Secondly, the external validity of our analysis is limited. In other institutions where the proportion of patients with advanced hepatic failure is high, the requirements for monitoring pulmonary artery pressure would be greater compared to our institution where most of the cases are living donor transplantation with lower MELD scores. Thirdly, the association of recently increasing intraoperative TEE monitoring with our outcomes was not investigated in our study. Further studies are required to investigate whether TEE monitoring could substitute the use of PAC. Fourthly, our cohort was from a relatively long period. Although we analyzed the timing of surgery as a covariate in our multivariable analysis and propensity analysis, the versions of cardiac output monitoring for PAC and FloTrac Vigileo have been updated during the data collection period. The update of software may have reduced the difference in the accuracy of cardiac output measurement between the thermodilution technique and arterial waveform analysis. The surgical technique, the amount of bleeding and transfusion have improved over time which could be a confounding factor in interpreting our analysis results. To address this, we analyzed the subgroup of recent years, but we could not find any significant results. Fifthly, the incidence of postreperfusion syndrome was not compared between groups. As the severity of baseline liver disease increases, monitoring with PAC would be more valuable and may yield significant differences in the clinical outcomes. Sixthly, we defined postoperative AKI based on KDIGO criteria, using serum creatinine changes only. Urine output criteria were not used in our analysis. Finally, new definition of EAD such as the Liver Graft Assessment Following Transplantation (L-GrAFT) score and the Early Allograft Failure Simplified Estimation (EASE) score has been introducedIn conclusion, in this large single-center retrospective observational study, we could not find any significant difference in clinical outcomes after liver transplantation between the group that used PAC and the group without PAC. Based on our results, anesthesia without the use of PAC during liver transplantation may be possible for low-risk patients. However, our study results should be interpreted cautiously because our cohort included many elective living donor liver transplants with low MELD scores, short ischemic time, and a low incidence of pulmonary hypertension. Our subgroup analysis revealed a significant difference in the incidence of PRS between the PAC group and the non-PAC group in the subgroup with a high MELD score. Also, in the high CIT group, both PRS and AKI showed significant differences between groups. These results suggest that it is important to delicately identify candidates to apply arterial waveform-based monitoring instead of PAC monitoring. The risk should be carefully assessed by considering MELD scores, ischemic time, surgical history, previous treatment of underlying liver disease, and degree of portal and pulmonary hypertension. Cardiac output monitoring with arterial waveform analysis may replace the use of PAC during liver transplantation. However, even for low-risk patients, a back-up hemodynamic strategy such as TEE should be prepared.Supplementary Information.


Vulvar leiomyomas are rare benign tumors originating from smooth muscle cells of the vulvar tissue. We present the case of a 44-year-old female patient complaining of a painless vulval mass for 12 years, gradually increasing from 1x1 cm to 5x4 cm. Clinical assessment initially suggested a Bartholin cyst because of its non-tender and non-fluctuant nature. However, surgical intervention revealed an unexpected diagnosis of vulvar leiomyoma, measuring 5x5x4 cm. The patient underwent successful excision and repair under spinal anesthesia. This case underscores the significance of meticulous clinical evaluation and accurate histopathological examination in distinguishing vulvar masses. Accurate diagnosis guides appropriate management, and long-term follow-up prevents complications and recurrence. This report highlights the diagnostic challenges of rare vulvar lesions and the importance of a comprehensive approach to their evaluation and treatment. Vulvar leiomyomas are notably rare among gynecologic neoplasms and vulvar tumors, originating from the smooth muscle cells within the vulvar tissue . While tIn contrast, clinicians often encounter more prevalent vulvar conditions, such as Bartholin cysts. Bartholin cysts, characterized by localized vulvar swelling, exhibit a significantly higher incidence compared to vulvar leiomyomas . The cliBartholin cysts are typically painless, subcutaneous swellings located near the posterior aspect of the labia majora . Their eAccurate diagnosis is crucial for guiding appropriate treatment decisions. Vulvar leiomyomas, albeit rare, require a distinct approach, often involving surgical excision . The surIn this case report, we present a patient who initially presented with a painless vulval mass clinically diagnosed as a Bartholin cyst because of its non-tender and non-fluctuant nature. Subsequent surgical exploration revealed a surprising histopathological diagnosis of vulvar leiomyoma. This report emphasizes the importance of accurate clinical assessment, histopathological evaluation, and appropriate surgical intervention for managing vulvar lesions. Through this case, we highlight the complexities of diagnosing rare vulvar conditions and underscore the need for a comprehensive approach to their assessment and treatment.We present the case of a 44-year-old female patient who presented with a longstanding complaint of a painless vulval mass. The mass had been present for 12 years and had gradually increased from an initial measurement of 1x1 cm to the current dimensions of 5x4 cm  staining revealed a distinctive tissue architecture. The specimen exhibited a pattern of benign-appearing spindle cells organized into interacting bundles. These spindle cells displayed oval to spindle-shaped nuclei and eosinophilic cytoplasm, consistent with the characteristic features of leiomyoma cells. Furthermore, intervening fibrous septa and dilated, congested vessels within the tissue were noted. Notably, no evidence of malignancy was observed in the sections examined, which confirms the benign nature of the vulvar leiomyoma. These histopathological findings align with the clinical diagnosis and concord with the immunohistochemical results, collectively supporting accurately characterizing the lesion as a benign vulvar leiomyoma Figure .An immunohistochemistry analysis of the excised vulvar leiomyoma revealed notable findings. Desmin staining exhibited diffuse and strong positivity Figure , confirmRoutine investigations, including coagulation profile, liver and renal function tests, chest X-ray, and ECG were all within normal limits. Furthermore, an abdominal and pelvic ultrasound showed no abnormalities. This case underscores the importance of accurate clinical evaluation and histopathological diagnosis in managing vulvar masses. Vulvar leiomyomas are relatively uncommon, and their presentation can mimic other vulvar conditions, as evidenced by the initial clinical diagnosis of a Bartholin cyst. Long-term follow-up may be recommended to monitor the patient's condition and detect potential recurrences or complications.The presented case of a 44-year-old female patient with a longstanding painless vulval mass highlights the challenges in diagnosing and managing rare vulvar lesions. Based on the patient's history and physical examination, the initial clinical diagnosis of a Bartholin cyst underscores the importance of considering a broad differential diagnosis for vulvar masses. Moreover, this case report emphasizes the significance of accurate clinical evaluation and histopathological diagnosis in guiding appropriate management strategies. Vulvar masses encompass a wide range of benign and malignant conditions, each with distinct clinical and histopathological characteristics . Accurate clinical assessment and histopathological diagnosis guide appropriate management and prevent misdiagnosis. This case serves as a reminder of the diverse differential diagnoses for vulvar masses and underscores the importance of a multidisciplinary approach to patient care. Further research and long-term follow-up are needed to enhance our understanding of these uncommon vulvar neoplasms and optimize their management strategies.The presented case highlights the diagnostic intricacies associated with rare vulvar conditions, precisely the challenge of distinguishing between vulvar leiomyomas and Bartholin cysts. Accurate clinical evaluation is paramount, as these lesions share standard features, including painless presentation and localized swelling. The case underscores histopathological confirmation's significance in preventing misdiagnosis and ensuring appropriate management. The management of vulvar lesions demands tailored approaches to achieve optimal outcomes. Surgically excising vulvar leiomyomas requires careful planning because of their location and potential impact on cosmetic and functional aspects. A misdiagnosis of these lesions can lead to unnecessary interventions or inadequate treatment. This report highlights the importance of a comprehensive diagnostic approach involving clinical assessment and histopathological examination to differentiate between similar vulvar presentations. This distinction has crucial implications for patient management, emphasizing the significance of accurate diagnosis in providing effective and patient-centered care. The case underscores clinicians' need for ongoing vigilance and awareness when encountering rare vulvar lesions, ensuring that patients receive the most appropriate interventions.