A more precise method to insert the needle for haemodialysis
Vascular surgery encompasses a wide spectrum of conditions, ranging from vascular access problems to venous, arterial and aortic diseases, and traumatic injuries.

It is particularly vital in haemodialysis as it addresses vascular access needs through three primary functions: creating vascular access, maintaining the vascular access and repairing any vascular complications that might arise.

Haemodialysis is a treatment that filters the metabolic waste of our body from the blood via a dialysis machine.

The machine essentially takes over the function of our kidneys, so it is used for those whose kidneys are failing or no longer work.

It is a lifelong treatment, with patients usually having to undergo the process three times a week for three to five hours per session in a haemodialysis centre.

Permanent access

Due to the required frequency of haemodialysis, there needs to be permanent access to the patient’s bloodstream in order to be easily hooked up to the dialysis machine.

This is where the vascular surgeon comes in.

They provide vascular access for haemodialysis through the creation of an arteriovenous fistula (AVF) or by inserting a central venous catheter.

An AVF is made by joining an artery and a vein in the patient’s arm.

Meanwhile, a central venous catheter is a soft tube that is placed under the skin and in one of the patient’s large central veins.

AVFs are usually preferred as they are less prone to infection and complications, compared to central catheters.

However, AVFs typically require six weeks to three months to mature before use, while central catheters can be used immediately.

The process of creating and maturing AVFs is complicated and plays a crucial role in ensuring effective dialysis.

Therefore, in some cases, a temporary central venous catheter might be inserted first for haemodialysis to proceed, while waiting for the patient’s AVF to mature.

At the beginning of each haemodialysis session, cannulation has to be performed to access the AVF.

This is where a trained nurse inserts a cannula – i.e. a needle connected to a soft tube that can, in turn, be connected to other longer tubes – into the AVF.

Central catheters meanwhile, can be connected directly to the machine.

Once all the necessary tubes are properly connected to the dialysis machine, the process of the patient’s blood flowing out into the machine, getting filtered and “cleaned”, then flowing back into the patient, begins.

During this process, patients are required to remain still so as to prevent dislodgement of the cannula.

Once the dialysis is completed, the tubes and cannula are removed, and the necessary dressings applied.

Due to frequency of haemodialysis, there needs to be permanent access to the patient’s bloodstream in the form of an AVF or central venous catheter, in order for them to be easily hooked up to the dialysis machine.

With ultrasound help

Cannulation is usually done blind, i.e. the nurse has to use their hand or fingers to locate the AVF, then use their experience to estimate the best place to insert the cannula needle in order to gain access to the AVF.

Now, however, a new technique known as ultrasound- guided needle cannulation has emerged.

This promises to be a gamechanger in managing vascular complications related to haemodialysis.

Ultrasound-guided needle cannulation enhances precision and reduces the risk of complications during cannulation.

As per its name, It utilises real-time imaging provided by ultrasound to visualise veins, ensuring precise needle placement and minimising the complications associated with the blind cannulation technique.

While it may not directly manage complications, ultrasound-guided cannulation serves as a preventive measure, minimising the likelihood of improper cannulation and associated vascular issues.

A vascular surgeon will demonstrate the procedure first, providing guidance and instruction to the haemodialysis team.

Such workshops should include mannequin-based hands-on training or exercises.

Once the haemodialysis nurses demonstrate competency and achieve the minimum requirement – typically after 50 patient assessments over a three to four month period – they can advance to performing cannulation under ultrasound guidance.

This phased approach not only instils confidence, but also ensures patient safety and optimal outcomes.

In addition, this collaborative approach helps foster skill development, as well as ensures the comprehensive integration of ultrasound guidance into clinical practice.

The Health Ministry is still in the process of implementing this new protocol for patients, but it is hoped that this safer and more precise method of cannulation will help maintain the long-term viability of vascular access for haemodialysis patients, as well as help prevent vascular complications.

Problems with blood vessels

Complications related to blood vessels during haemodialysis can occur due to several factors.

Inappropriate or missed cannulation during haemodialysis may cause issues like bleeding, rupture of the AVF, pseudoaneurysm and formation of venous aneurysms.

An aneurysm is an abnormal bulge or swelling in the wall of a blood vessel, while a pseudoaneurysm is a bleed from a torn blood vessel that is contained by the surrounding tissue – usually blood clots.

High-flow AVFs can also result in complications such as venous aneurysm, central vein stenosis (narrowing) and steal syndrome (where there is decreased, or even reversed, blood flow in the artery before the fistula), which may require surgical intervention or other treatments.

This is where vascular surgeons step in again.

They help maintain vascular access by performing interventions like balloon fistuloplasty or central venoplasty to address stenosis or occlusion, ensuring optimal blood flow for dialysis.

And they repair complications like pseudoaneurysms, venous aneurysms or thrombosed AVFs through techniques like thrombolysis or bypass procedures, thereby preserving access and facilitating continued haemodialysis treatment.

These interventions aim to prevent further complications and ensure optimal vascular health for patients undergoing haemodialysis.

Patients themselves can also help to manage their vascular health by making some positive changes to lifestyle habits.

To prevent health issues, it is important to quit smoking, exercise regularly and follow a healthy diet.

Compression stockings can help manage venous diseases as they help prevent leg swelling, and to a lesser extent, blood clots.

Meanwhile, managing weight, and keeping high blood pressure and diabetes under control, can also help prevent vascular complications.

It is also crucial to identify and treat any ulcers early on to avoid potential vascular-related problems.

Dr Syaiful Azzam Sopandi is a consultant general and vascular surgeon. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this article. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
Wellness,Haemodialysis,ultrasound,chronic kidney disease,kidney failure,non-communicable diseases,NCDs
This new technique will enable nurses to rely on more than their sense of touch and experience to cannulate haemodialysis patients.