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

Abstract

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.

Endovascular treatment of previously clipped aneurysms: continued evolution of hybrid neurosurgery

“…Although aneurysm clipping is associated with high rates of initial occlusion and durability,16 17 these rates remain imperfect and inflated by the use of non-invasive postoperative imaging. Critical residual or recurrent components of an aneurysm can be missed (figures 1, 2).…”

Incidence, classification, and treatment of angiographically occult intracranial aneurysms found during microsurgical aneurysm clipping of known aneurysms

“…7 Of note, the presence of multiple aneurysms has been identified as a risk factor for de novo aneurysm formation in prior reports. [1][2][3]18 The presence of multiple aneurysms was a strong and independent predictor of AO aneurysms in our cohort (42.0% vs 20.0%, OR…”

Microsurgical Clip Suspension to Prevent Optic Neuropathy Following Ligation of Anterior Communicating Artery Aneurysm: A Technical Report and Surgical Video

“…Several studies have demonstrated the efficacy of microsurgical clip ligation in the treatment of cerebral aneurysms through long-term follow-up angiography, with a 0.14% recurrence rate of nearly 700 clipped aneurysms without residua [9]. Bohnstedt et al investigated 319 cases of ACoA aneurysms treated with microsurgical clip ligation [8].…”