No abstract

BACKGROUNDDuring surgery in the posterior fossa in the prone position, blood can sometimes fill the surgical field, due both to the less efficient venous drainage compared to the sitting position and the horizontally positioned surgical field itself. In some cases, blood clots can wedge into the cerebral aqueduct and the third ventricle, and potentially cause acute hydrocephalus during the postoperative course.OBJECTIVETo illustrate a technique that can be used in these cases: the use of a flexible scope introduced through the opened roof of the fourth ventricle with a freehand technique allows the navigation of the fourth ventricle, the cerebral aqueduct, and the third ventricle in order to explore the cerebrospinal fluid pathways and eventually aspirate blood clots and surgical debris.METHODSWe report on one patient affected by an ependymoma of the fourth ventricle, for whom we used a flexible neuroendoscope to explore and clear blood clots from the cerebral aqueduct and the third ventricle after the resection of the tumor in the prone position. Blood is aspirated with a syringe using the working channel of the scope as a sucker.RESULTSA large blood clot that was lying on the roof of the third ventricle was aspirated, setting the ventricle completely free. Other clots were aspirated from the right foramen of Monro and from the optic recess.CONCLUSIONWe describe this novel technique, which represents a safe and efficient way to clear the surgical field at the end of posterior fossa surgery in the prone position. The unusual endoscopic visual perspective and instrument maneuvers are easily handled with proper neuroendoscopic training.

Background: Flow 800 is microscope-integrated analytical visualization tool which analyses the indocyanine green (ICG) video sequence and converts it into an intensity diagram. This allows an objective evaluation of the result rather than subjective assessment of ICG fluorescence. The anatomy of anterior communicating artery region is complex because of multiple vessels and perforators in small space; hence, there is a need of objective assessment tool which can give precise idea about vascular compromise. Flow 800 can serve as a valuable tool in this complex surgery. Objective: The objective of this study was to evaluate the utility of microscope-integrated fluorescent ICG videoangiography (Flow 800) in A-com aneurysm surgery. Materials and Methods: We used Flow 800 in ten consecutive patients of A-com aneurysm surgery from July 2019 to October 2019. We studied patient characteristics, intraoperative observation of ICG and Flow 800, and corresponding changes made in the operative decisions. Results: The use of Flow 800 helped in intraoperative decision of four out of ten patients of A-com aneurysm. In two patients, incomplete clipping was confirmed with Flow 800 and the second clip was applied. In the third patient, perforator compromise was found hence needed clip readjustment, whereas in the fourth patient, ICG was inconclusive and Flow 800 confirmed complete clipping of aneurysm. Conclusion: Flow 800 is a conclusive reproducible and objective tool for early detection of vascular compromise of multiple vessels and perforators in A-com aneurysm surgery. It gives a better idea of vasculature, especially where ICG is ambiguous or inconclusive.

Background: Anterior communicating (A-com) artery region is very complex; perforators are not always visualized on the microscope. The neuroendoscope with its higher magnification, better observation, and additional illumination can provide us information that may not be available with the microscope in aneurysm surgery. Objective: The objective was to study the use of endoscope in surgical management of A-com aneurysm surgery and its advantages, whether and how it changes operative management. Materials and Methods: We studied 25 serial cases of A-com aneurysm at Bantane Hospital, Fujita University, Japan, from November 2018 to October 2019. Once aneurysm was exposed, we did preclipping indocyanine green (ICG) study and examination with endoscope. After clipping, we again did ICG and endoscopic assessment. Preclipping and postclipping endoscopic information was used and necessary changes were made in the operative decisions. Whether endoscope gives any additional information over microscope and ICG which led to change in the operative decision was assessed. Results: In six out of 25 A-com aneurysm patients, the use of endoscope has given additional information over microscope, and ICG leading to change in the operative plans such as readjustment of the clip/application of the second clip or release of perforator compromise. Conclusion: Simultaneous endoscopic and microscopic guidance can reveal important information hidden from the microscope. Thus, this method increases the safety and durability of the A-com aneurismal clipping.