Role of clipping in aneurysmal subarachnoid hemorrhage: a post hoc analysis of the Earlydrain trial

The choice between clipping and coiling of ruptured cerebral aneurysms in subarachnoid hemorrhage (SAH) remains controversial. The recently published Earlydrain trial provides the opportunity to analyze the latest clip-to-coil ratio in German-speaking countries and to evaluate vasospasm incidence and explorative outcome measures in both treatment modalities. We performed a post hoc analysis of the Earlydrain trial, a multicenter randomized controlled trial investigating the use of an additional lumbar drain in aneurysmal SAH. The decision whether to clip or to coil the ruptured aneurysm was left to the discretion of the participating centers, providing a real-world insight into current aneurysm treatment strategies. Earlydrain was performed in 19 centers in Germany, Switzerland, and Canada, recruiting 287 patients with aneurysmal SAH of all severity grades. Of these, 140 patients (49%) received clipping and 147 patients (51%) coiling. Age and clinical severity based on Hunt-Hess/WFNS grades and radiological criteria were similar. Clipping was more frequently used for anterior circulation aneurysms (55%), whereas posterior circulation aneurysms were mostly coiled (86%, p < 0.001). In high-volume recruiting centers, 56% of patients were treated with clipping, compared to 38% in other centers. A per-year analysis showed a stable and balanced clipping/coiling ratio over time. Regarding vasospasm, 60% of clipped versus 43% of coiled patients showed elevated transcranial Doppler criteria (p = 0.007), reflected in angiographic vasospasm rates (51% vs. 38%, p = 0.03). In contrast to the Earlydrain main results establishing the superiority of an additional lumbar drain, explorative outcomes after clipping and coiling measured by secondary infarctions, mortality, modified Rankin Score, Glasgow Outcome Scale Extended, or Barthel-Index showed no significant differences after discharge and at six months. In clinical practice, aneurysm clipping is still a frequently used method in aneurysmal SAH. Apart from a higher rate of vasospasm in the clipping group, an exploratory outcome analysis showed no difference between the two treatment methods. Further development of periprocedural treatment modalities for clipped ruptured aneurysms to reduce vasospasm is warranted.