German Society of Neurosurgery Section on Vascular Neurosurgery: Position Statement on the International Subarachnoid Hemorrhage Trial (ISAT).

The outcome after a specific treatment (clipping or coiling) of ruptured intracranial aneurysms is determined by both the periprocedural complication rate and the success of preventing re-bleeding from the treated aneurysm. The latter is associated with a cumulative risk over many years, particularly in incompletely treated aneurysms. Incomplete occlusion of the aneurysm is not infrequently seen after endovascular coiling, even in cases with a perfect anatomical configuration. Therefore, we believe that the 1-year outcome as reported in the ISAT is not an appropriate endpoint for the comparison of both methods. There has also been a tendency to apply the 1-year ISAT data to all patients harbouring intracranial aneurysms. It is inappropriate and dangerous to be less critical when selecting the endovascular approach as the method of choice for treating an aneurysm. This will ultimately result in a higher complication rate of coiling. Another striking finding is the poor surgical outcome in the ISAT. This good-grade patient population (94 % were WFNS grade 1-3 and 89 % were WFNS grade 1-2) had an almost 10 % higher rate of poor outcome compared to other good-grade patients in large prospective surgical studies or the same outcome as trials that included up to 20 % poor-grade patients.[nl]Neurosurgeons should acknowledge that endovascular coiling is a safe method associated with less complications than clipping in experienced hands (Fig. ). Endovascular radiologists should acknowledge that the success of complete obliteration is higher after surgery, that incompletely occluded aneurysms have a higher rate of re-rupture and that the definitive long-term re-rupture rate still remains unknown. Therefore, we await with interest the angiographic and clinical follow-up data that will provide evidence about the final patient outcome.