Does Intraoperative Angiographic Vasospasm during Aneurysm Clipping influence the Incidence of Delayed Cerebral Vasospasm and Delayed Neurological Deficit?

Aims: Delayed cerebral vasospasm (dCVS) occurs in more than half of the patients with SAH and is associated with delayed neurological deficits (DND) mostly between days 4 and 15 after ictus. The incidence of acute CVS within 72 hours after SAH is controversial. Acute surgically-induced CVS might influence the incidence of dCVS and outcome of patients undergoing clipping or coiling of ruptured and unruptured aneurysms. The aim of this study was to elucidate the incidence of intraoperative angiographic CVS (iCVS) during aneurysm surgery and analyze its possible role on the risk for dCVS and DND.

Methods: We retrospectively reviewed the intraoperative angiograms of 139 consecutive patients who underwent surgical or interventional occlusion of aneurysms during a 4-year period in our institution. iCVS Categorization: Percent stenosis= [1-(Dstenosis/Dnormal)] x 100 (Dstenosis = artery diameter at site of most severe stenosis/ Dnormal = diameter of same artery before treatment, alternatively diameter of most proximal “normal” segment of artery). Spasm severity was classified with respect to reduction in transverse diameter (mild 10-30%, moderate 30-50%, and severe >50%). Results: Final analysis included 109 patients, 77 had acute SAH and 32 were treated for incidental aneurysms. Patients with acute SAH had a higher incidence of iCVS than patients undergoing elective aneurysm treatment (p = 0.02). 17/77 (22%) patients with SAH had evidence of iCVS. Only one patient (3%) had iCVS in the elective treatment group. The severity of iCVS was documented as follows: mild (9 patients, 53%), moderate (5 patients 29%), and severe (3 patients, 18%). Among patients with SAH, CVS on admission and prior to intervention could be documented in only 1 (5.9%) out of 17 patients. The incidence of dCVS, DND, and poor outcome (mRS≥3) in patients with iCVS during surgical treatment of ruptured aneurysms was 56% (p = 0.001), 63% (p = 0.02), and 38% (p = 0.14) respectively.

Conclusions: The incidence of iCVS in patients undergoing treatment for ruptured intracranial aneurysms has been underestimated, especially during surgical occlusion of ruptured aneurysms. Surgically-induced iCVS has to be considered as an important influencing factor. In this series, a significant correlation between iCVS and dCVS or DND could be documented. Further studies are warranted to investigate the pathogenesis of iCVS, namely acute CVS, and its influence on the outcome after acute treatment of SAH.