Long-term surgical outcomes of XXXX .

@entity5 @entity1 @entity1653 @entity1758
STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate the treatment strategies for @entity1653 . SUMMARY OF BACKGROUND DATA: Although previous studies have demonstrated favorable surgical outcomes for @entity1653 , with a low incidence of @entity5 recurrence, few have examined long-term surgical outcomes. METHODS: The influence of @entity1 age, surgical margin status (Simpson grade), @entity5 location, and histological subtype on @entity5 recurrence were examined retrospectively. In addition, the resected dura mater from Simpson grade I cases was examined for invasive @entity5 cells and compared with the presence or absence of a dural tail sign on magnetic resonance image. RESULTS: Complete resection (Simpson grades I and II) was performed in 62 @entity1 . Among them, the @entity5 recurrence rate was 9.7%, all in @entity1 who underwent grade II resection for ventral spinal lesions. The mean duration to reoperation in these @entity1 was 12.2    5.2 years. Of the 6 @entity1 who underwent incomplete resection (Simpson grade III/IV), all required reoperation for @entity5 recurrence or regrowth, 5 years later on average. @entity1 younger than 50 years at the initial surgery had a significantly higher recurrence rate than those aged 50 years or older. Histologic examination of 43 dura mater specimens from Simpson grade I-resection @entity1 revealed @entity5 cell invasion between the inner and outer layers in 15 @entity1 . This invasion was noted in 8 (29%) of 28 @entity1 who were negative for the dural tail sign on magnetic resonance image, and in 7 (47%) of 15 @entity1 who showed a positive dural tail sign. The @entity1758 index reached about 10% for dumbbell-type @entity1653 invading the vertebral body; these were associated with repeated recurrence and unfavorable prognosis. CONCLUSION: Long-term follow-up after surgery for @entity1653 indicated that Simpson grade I resection should be selected whenever practicable when treating younger @entity1 or dumbbell-type @entity1653 . @entity5 recurred at 12 years, on average, in approximately 30% of @entity1 who underwent grade II resection.
