The durability of endovascular coiling versus neurosurgical clipping of ruptured cerebral aneurysms: 18 year follow-up of the UK cohort of the International Subarachnoid Aneurysm Trial (ISAT)

Abstract

SummaryBackgroundPrevious analyses of the International Subarachnoid Aneurysm Trial (ISAT) cohort have reported on the risks of recurrent subarachnoid haemorrhage and death or dependency for a minimum of 5 years and up to a maximum of 14 years after treatment of a ruptured intracranial aneurysm with either neurosurgical clipping or endovascular coiling. At 1 year there was a 7% absolute and a 24% relative risk reduction of death and dependency in the coiling group compared with the clipping group, but the medium-term results showed the increased need for re-treatment of the target aneurysm in the patients given coiling. We report the long-term follow-up of patients in this UK cohort.MethodsIn ISAT, patients were randomly allocated to either neurosurgical clipping or endovascular coiling after a subarachnoid haemorrhage, assuming treatment equipoise, between Sept 12, 1994, and May 1, 2002. We followed up 1644 patients in 22 UK neurosurgical centres for death and clinical outcomes for 10·0–18·5 years. We assessed dependency as self-reported modified Rankin scale score obtained through yearly questionnaires. Data for recurrent aneurysms and rebleeding events were collected from questionnaires and from hospital and general practitioner records. The Office for National Statistics supplied data on deaths. This study is registered, number ISRCTN49866681.FindingsAt 10 years, 674 (83%) of 809 patients allocated endovascular coiling and 657 (79%) of 835 patients allocated neurosurgical clipping were alive (odds ratio [OR] 1·35, 95% CI 1·06–1·73). Of 1003 individuals who returned a questionnaire at 10 years, 435 (82%) patients treated with endovascular coiling and 370 (78%) patients treated with neurosurgical clipping were independent (modified Rankin scale score 0–2; OR 1·25; 95% CI 0·92–1·71). Patients in the endovascular treatment group were more likely to be alive and independent at 10 years than were patients in the neurosurgery group (OR 1·34, 95% CI 1·07–1·67). 33 patients had a recurrent subarachnoid haemorrhage more than 1 year after their initial haemorrhage (17 from the target aneurysm).InterpretationAlthough rates of increased dependency alone did not differ between groups, the probability of death or dependency was significantly greater in the neurosurgical group than in the endovascular group. Rebleeding was more likely after endovascular coiling than after neurosurgical clipping, but the risk was small and the probability of disability-free survival was significantly greater in the endovascular group than in the neurosurgical group at 10 years.FundingUK Medical Research Council.

Hydrogel versus Bare Platinum Coils in Patients with Large or Recurrent Aneurysms Prone to Recurrence after Endovascular Treatment: A Randomized Controlled Trial

“…Thus, clipping, reputed but not proved, at least for unruptured aneurysms, 31 to be more durable than coiling, is a reasonable option for some of these patients, though the long-term follow-up ISAT data con- firm a low rebleed risk after de novo coiling and long-term outcome superiority over clipping. 9 Patients with large ruptured aneurysms could be offered participation in the ISAT II trial.…”

Effect of treatment modality on in-hospital outcome in patients with subarachnoid hemorrhage: a nationwide study in Japan (J-ASPECT Study)

“…However, the ISAT reported that the probability of death or dependency at 2 months, 1 year, and 10 years after treatment were higher in the clipping group. 19,20 Results of the ISAT suggest that short-term outcomes regarding mRS scores and mortality may serve as reasonable predictive markers for long-term outcomes. Fourth, the external validity of the CSC grading system has not been confirmed.…”

“…7,[17][18][19][20][21]26,28,30,31 The International Subarachnoid Aneurysm Trial (ISAT), a large randomized controlled trial (RCT) that compared neurosurgical clipping with endovascular coiling in patients with SAH, demonstrated the superiority of coiling. 20 This finding of the ISAT led to a prominent shift in the pattern of treatment for SAH, with the number of coiling procedures steadily increasing following publication.…”

Analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial

“…Finally, the study protocol for the BRAT did not include an anticipated analysis restricted to saccular aneurysms. However, in light of the fact that all other randomized trials comparing clipping and coil- 7 Although the remaining 3 studies 4,5,11 were statistically underpowered, it is noteworthy that the larger 2 of the 3 (i.e., the BRAT 11 and the study by Li et al 5 ) both showed 1-year trends of a magnitude similar to the original ISAT 9 results favoring endovascular treatment. In this analysis of saccular aneurysms in the BRAT, there were 5.5% (p = 0.29) fewer poor outcomes in the coiling group at 1 year, whereas in the study by Li et al there were 9.4% fewer dead or disabled patients in the endovascular treatment group.…”