Beneficial effects of clazosentan add-on treatment on delayed cerebral microcirculatory disturbances after aneurysmal subarachnoid hemorrhage

This retrospective study aimed to analyze the prospectively collected data of computed tomography (CT) perfusion imaging and to examine if clazosentan add-on administration prevented post-subarachnoid hemorrhage (SAH) delayed cerebral microcirculatory dysfunctions. A total of 36 consecutive patients with non-mild SAH due to ruptured anterior circulation aneurysms and no significant cardiopulmonary dysfunctions (mean age, 67.9 years; and admission World Federation of Neurological Surgeons grades IV–V, 66.7 %) underwent aneurysmal obliteration up to day 3 post-SAH, followed by our conventional treatment (fasudil hydrochloride, cilostazol and perampanel administrations; n = 20; January 2020 to May 2022) or add-on administration of clazosentan (10 mg/hr) to the conventional treatment (n = 16; June 2022 to May 2023). Clazosentan add-on treatment significantly affected perioperative fluid management, which appeared to have no effects on the finding of CT perfusion imaging performed a median of 6.5 to 7.0 days post-SAH. However, cerebral blood flow and mean transit time were better in patients receiving add-on administration of clazosentan, although angiographic vasospasm frequencies and cerebral blood volume values were similar between the two treatment groups. The findings suggest that clazosentan add-on treatment has beneficial effects against post-SAH angiographic vasospasm-unrelated delayed cerebral microcirculatory dysfunctions possibly by improving blood flow in smaller resistance arteries or arterioles.