Posterior Cerebral Artery-to-Superior Cerebellar Artery Side-to-Side Bypass via Extreme Lateral Supracerebellar Infratentorial Approach: Technical Note.

BACKGROUND: Difficult-to-treat aneurysms of the distal posterior cerebral artery (PCA) can often be treated by parent artery occlusion. A cerebrovascular bypass can complement PCA occlusion to curb the risk of ischemic complications. An in situ bypass may be considered when the occipital artery or superficial temporal artery cannot serve as a bypass donor. This article describes the use of a side-to-side bypass of superior cerebellar artery as a donor to the PCA via an extreme lateral supracerebellar infratentorial approach (ELSCIT). This bypass approach can be a useful surgical strategy for PCA revascularization. METHODS: A 40-year-old woman underwent a side-to-side PCA-superior cerebellar artery bypass via the ELSCIT approach for to treat a complex and previously coiled PCA aneurysm. The bypass was followed by endovascular aneurysm and parent artery occlusion. RESULTS: Postoperatively, the patient experienced transient, partial trochlear nerve palsy of the left eye without ischemic lesions on magnetic resonance imaging. The clinical condition was stable, and angiography showed a patent bypass and complete aneurysm occlusion 12 months after surgery. CONCLUSIONS: The ELSCIT approach offers access to the medial and distal PCA that is suitable for a side-to-side PCA-superior cerebellar artery bypass. This type of approach and bypass may be of value when revascularization of a P2-P3 portion of the PCA is needed, but a suitable occipital artery or superficial temporal artery is not available.

Efficacy and histopathological effects of self-assembling peptides RADA16 and IEIK13 in neurosurgical hemostasis.

There is a continued need for effective hemostatic agents that are safe for neurosurgical use. Self-assembling peptide hydrogels have been suggested as novel hemostatic agents. They offer some advantages for neurosurgical hemostasis (e.g., transparency), but their efficacy and safety for neurosurgery have not been established. In this paper, the efficacy and safety of two self-assembling peptides, RADA16 and IEIK13, are explored for hemostasis of oozing bleeding on the rat cerebral cortex (n = 56). Chronic safety was evaluated by neuropathological evaluation at one, four, and twelve weeks after craniotomy (n = 32). An inactive control and oxidized cellulose served as comparators. Mean time-to-hemostasis was significantly shorter for RADA16 and IEIK13 compared to controls, while safety evaluation yielded similar results. Histopathological response consisted primarily of macrophage infiltration at the lesion site in all groups. This study confirms the hemostatic potential and safety of RADA16 and IEIK13 for hemostasis in the rat brain.

Polyvinyl Alcohol Sponges to Facilitate Cerebral Bypass Surgery: Technical Note.

OBJECTIVE: The standard way of isolating bypass vessels from surrounding structures during cerebral bypass surgery has been to use a rubber dam or neurosurgical patty. Here, the use of polyvinyl alcohol (PVA) sponges is described as a possible upgrade from these traditional bypass dams. METHODS: PVA sponges were used to isolate bypass arteries from surrounding tissues during microvascular anastomosis in 25 patients undergoing bypass surgery at our institution. RESULTS: There were no adverse events related to the use of PVA for microvascular anastomosis. PVA sponges offered some specific advantages when compared with rubber and cottonoid dams. CONCLUSIONS: Although preliminary, our experience using PVA sponges during microvascular anastomosis suggests some of their properties can facilitate cerebral bypass surgery.

Extreme Lateral Supracerebellar Infratentorial Approach (ELSCIT) for Occipital Artery-to-Posterior Cerebral Artery Bypass: Results in 3 Cases.

OBJECTIVE/BACKGROUND: The need for revascularization of the distal posterior cerebral artery (PCA) in the treatment of PCA aneurysms is a contentious issue. Approaches to the PCA, such as the subtemporal route, carry significant perioperative risk. This risk at times outweighs the risk of ischemia associated with endovascular PCA sacrifice. This paper describes the use of an extreme lateral supracerebellar infratentorial (ELSCIT) approach as an alternative technique for distal PCA revascularization. METHODS: Between 2016 and 2019, 3 patients underwent a PCA bypass via the ELSCIT approach for the treatment of a PCA aneurysm. In all cases, an end-to-side anastomosis to the P2- or P3-segment of the PCA was made, with the occipital artery as a donor. Bypass procedures were followed by endovascular parent artery occlusion, without ischemic complications. RESULTS: In all 3 cases, the ELSCIT approach offered a broad enough surgical corridor to perform an occipital artery-to-PCA bypass. One patient suffered a cerebrospinal fluid leak that was surgically treated. Patients' clinical conditions were stable on follow-up (mean follow-up of 34 months). All 3 aneurysms remained occluded, and no ischemia was detected on magnetic resonance imaging. CONCLUSIONS: The ELSCIT approach offers an alternative route to the distal PCA for extracranial-to-intracranial bypass with seemingly low perioperative morbidity and good surgical access to the PCA.

Ruptured blood blister like aneurysm: does the best therapeutic option really exist?

Our study aimed to evaluate the outcome of patients with ruptured blood-blister like aneurysm (BBLA) in our institution by comparing microsurgical selective treatment to endovascular treatment using flow-diverter stent (FD). Our study included 18 consecutive patients treated for BBLA between 2004 and 2020. Until 2014, microsurgery was preferred in all patients with BBLA (n = 10). Significant postoperative morbi-mortality was recorded at this time and led us to change therapeutic strategy and to favor FD as first-line treatment in all patients (n = 8). Postprocedural complications and BBLA occlusion were recorded. High WFNS score (> 2) was noted in 6 patients of microsurgical group and in 2 of endovascular group. In microsurgical group, ischemic lesions were noted in 6 patients and led to death in 3 patients. Immediate BBLA occlusion was obtained in all patients. Favorable outcome after 3 months (mRS < 3) was recorded in 4 of the 7 survivors. In endovascular group, ischemic lesions were noted in 4 patients. One patient died from early postprocedural BBLA rebleeding. Scarpa hematoma was noted in 3 patients with surgical evacuation in 1. Persistent BBLA at 3 months was recorded in 4 patients without rebleeding, but further FD was required in 1 with growing BBLA. Favorable outcome was noted in 6 of the 7 survivors. Although, rate of morbi-mortality appear lower in patients treated with FD, neurological presentation was better and BBLA diagnosis remains questionable in this group. Moreover, persistent BBLA imaging with potential risk of rebleeding after FD deserves to be discussed.

Complete Transection of Optic Nerve After Endovascular Coiling of a Large Ophthalmic Artery Aneurysm.

BACKGROUND: We describe a patient who developed delayed blindness of the left eye at 5 weeks after endovascular coiling of a large ophthalmic aneurysm. CASE DESCRIPTION: A 44-year-old male was admitted with visual decline due to compression of the optic nerve by a large ophthalmic aneurysm. The aneurysm was treated by endovascular coiling, but visual function was unchanged. One month and 7 days later, the patient developed sudden blindness of the affected eye, despite complete angiographical occlusion of the aneurysm. Surgical exploration in an attempt to restore vision showed a fully thrombosed aneurysm but, surprisingly, complete transection of the optic nerve just proximal to its entry into the optic canal. CONCLUSIONS: This report describes a rare complication of a sudden increase in size of a large ophthalmic aneurysm despite successful endovascular occlusion.

Protective STA-MCA bypass to prevent brain ischemia during high-flow bypass surgery: case series of 10 patients.

BACKGROUND: High-flow extracranial-intracranial bypass is associated with a significant risk of ischemic stroke. The goal of this study is to evaluate the effectiveness of STA-MCA bypass preceding a high-flow bypass as a means of protecting the brain from ischemia during the high-flow bypass anastomosis in patients with otherwise untreatable aneurysms. MATERIALS AND METHOD: This prospective study included 10 consecutive patients treated for complex/giant aneurysm using a previous combined STA-MCA bypass and high-flow EC-IC bypass between June 2016 and January 2018 when classical endovascular or microsurgical exclusion was estimated too risky. Early cranial Doppler, MRI, CT scan, and conventional angiography were performed in each patient to confirm patency of bypasses, measure flow in the anastomoses, detect any ischemic lesions, and evaluate exclusion of the aneurysm. RESULTS: The mean age at treatment was 55 years (range 34 to 67). The mean time of microsurgical procedure was 11 h (range 9 to 12). In all patients, the high-flow bypass was patent intraoperatively and complete occlusion of aneurysm was obtained. No ischemic lesions were noted on early MRI. One patient died from a large hemispheric infarction related to a common carotid artery dissection 10 days after the microsurgical procedure and immediate postoperative epidural hematoma was noted in one other patient. CONCLUSION: In this study, we described the use of a protective STA-MCA bypass, performed prior to the high-flow bypass, in order to reduce the risk of perioperative ischemic lesions without increasing the morbidity of the surgical procedure. This treatment paradigm was feasible in all ten patients without complications related to the STA-MCA anastomosis.