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

Objective: 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. Methods: 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). Results: 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. Conclusion: 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.