Could late rebleeding overturn the superiority of cranial aneurysm coil embolization over clip ligation seen in the International Subarachnoid Aneurysm Trial?

Abstract

Object. The present purpose is to define the sensitivity of the superiority of coil embolization observed in the International Subarachnoid Aneurysm Trial (ISAT) according to the rate of late rebleeding over a reasonable range, and to find the range of rebleeding rates for which it may be overturned. In the ISAT, coil embolization appears to be safer than clip ligation at 1 year, and clip occlusion has better long-term efficacy at preventing rebleeding. This leaves open the question of which is better in the longer term.Methods. The authors calculate the life expectancy of patients following a subarachnoid hemorrhage (SAH) and compare the life expectancy of those who underwent coil embolization with those who underwent clip ligation in the ISAT cohort.Results. The 1-year poor outcome rate following treatment climbs rapidly with advancing age. A consequence is that the absolute difference between the poor outcome rates after coil embolization and clip occlusion is lower in those Ͻ 50 years of age (3.3%) than it is for those Ͼ 50 years of age (10.1%). This difference may be enough to give clip application the advantage in the Ͻ 40-year-old group despite the small size of the difference in 1-year rebleeding rates thus far observed (0.152%).Conclusions. When treating ruptured cerebral aneurysms, the advantage of coil embolization over clip ligation cannot be assumed for patients Ͻ 40 years old. In this age range the difference in the safety of the 2 procedures is small, and the better long-term protection from SAH afforded by clip placement may give this treatment an advantage in life expectancy for patients Ͻ 40 years of age.

Age-Related Trends in the Treatment and Outcomes of Ruptured Cerebral Aneurysms: A Study of the Nationwide Inpatient Sample 2001–2009

“…However, while coiling has become the procedure of choice for most patients, clipping is still being offered to a substantial number of patients, especially those who are younger. The lower use of coiling in younger patients is supported by the ISAT results, which showed little difference in outcomes for clipping and coiling for patients 40 years old and younger, 22 and by the better durability of surgical clipping.…”

The Barrow Ruptured Aneurysm Trial: 3-year results

“…1 Furthermore, follow-up data from the ISAT study suggest that younger patients may have better long- term outcomes when treated with clipping compared with coiling. 16 The entry criteria for ISAT and BRAT differed markedly. Only 22% of eligible patients were entered into ISAT.…”

The analysis of long - term follow - up screening in patients with surgically treated intracranial aneurysms

“…This final report demonstrated the increased risk of rebleeding from a coiled aneurysm compared with a clipped aneurysm although the number of recurrent bleeding episodes was very small in both treatment groups. At the conclusion of the ISAT, coil embolisation appeared to be more advantageous than clip ligation regarding death and severe disability at one year, and clip occlusion had better long-term efficacy in order to prevent recurrent bleeding and to result a better long-term outcome especially in patients younger than 40 years of age (19). Recently, The Barrow Ruptured Aneurysm Trial (BRAT) reported the initial results (18).…”