Jonathan Parish

A long-term study of durability and risk factors for aneurysm recurrence after microsurgical clip ligation

OBJECTIVE With the recent evolution of endovascular therapies, objective evaluation of the efficacy of clip ligation for cerebral aneurysms should be performed. This study was undertaken to evaluate the durability of microsurgical clip ligation, identify risk factors for recurrence, and assess the need for long-term follow-up imaging. METHODS A retrospective review of medical records identified 616 consecutive patients (156 male and 460 female patients; mean age 48.4 ± 12.4 years; range 6-90 years) who underwent microsurgical clip ligation and follow-up imaging at least 1 year after discharge between 1990 and 2010 at our institution. Of a total of 926 aneurysms in 616 patients, 758 aneurysms were microsurgically clip-ligated. At presentation, 431 of these aneurysms were ruptured and 327 aneurysms were unruptured. All patients underwent postoperative baseline imaging within the 1st month of their operation. A logistic regression analysis was performed to identify which variables are more likely to predict recurrence. RESULTS Late follow-up angiographic imaging was obtained at a mean of 7.2 ± 4.7 years postdischarge (median 5.7 years; range 1-23 years). Of the 699 clipped aneurysms without residua, late follow-up angiography revealed only 1 (0.14%) recurrent aneurysm. Of the 59 residual aneurysms that remained after initial clip ligation on early postoperative imaging, 8 (13.6%) demonstrated growth. All of these aneurysms required treatment. None of the recurrences were due to broken or delayed displacement of clips. A total of 111 patients presented with multiple aneurysms. De novo aneurysm formation occurred in 8 (0.97%) patients, all of whom initially presented with multiple aneurysms. CONCLUSIONS This study provides additional evidence to support the long-term efficacy of aneurysm clip ligation. The chance of aneurysm recurrence after complete clip ligation is very small. However, there is a regrowth risk of 1.83% per year for aneurysm remnants after incomplete clip ligation. These findings support the necessity for continued followup, late angiographic imaging, and the potential need for further intervention of incompletely ligated aneurysms. Furthermore, completely clip-ligated aneurysms may not require additional surveillance imaging unless multiple aneurysms were evident at presentation.

Intrasellar ependymoma: Clinical, imaging, pathological, and surgical findings

Ependymomas arising in the intrasellar compartment are extremely rare and most often are not included in the differential diagnosis of an intrasellar tumor mass. We review the literature to further advance awareness regarding unusual presentations of this type of tumor and present an illustrative case of an intrasellar cystic ependymoma that developed in an uncommon location. In our illustrative case, the patient had a 2 year history of hypopituitarism, but no headaches or visual disturbance. Preoperatively, the lesion was thought to be a pituitary macroadenoma.

Intrasellar pilocytic astrocytomas: Clinical, imaging, pathological, and surgical findings

A pilocytic astrocytoma is not usually considered in the differential diagnosis of an intrasellar tumor. An awareness of this tumor as primarily an intrasellar entity is important to avoid confusion during its diagnosis. We retrospectively examined the records of 631 patients treated at our institution between 2006 and 2010 who underwent transsphenoidal resection of pituitary tumors and identified those diagnosed with pilocytic astrocytoma. We excluded patients who harbored a pituicytoma. We also searched the literature for patients with a histologically confirmed diagnosis of intrasellar pilocytic astrocytoma. Only two patients in our series harbored intrasellar tumors and had a histologic diagnosis of pilocytic astrocytoma. We also found two other cases in the literature that met our criteria. Pilocytic astrocytoma should be considered in the differential diagnosis of an intrasellar lesion. An understanding of this tumors radiological features can avoid diagnostic confusion.