Todd C Hollon1, Luis E Savastano2, Davis P Argersinger2, Douglas J Quint3, B Gregory Thompson2. 1. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA. Electronic address: tocho@med.umich.edu. 2. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA. 3. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA; Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
Abstract
OBJECTIVE: To identify a potential microvascular etiology in patients who underwent vestibular schwannoma surgery (VSS) complicated by postoperative microvascular brainstem ischemia. METHODS: Charts were retrospectively reviewed of all patients who had an MRI within 14 days of VSS in years 2005-2016. Patient characteristics, preoperative and postoperative imaging features, clinical course and potential predictors of brainstem ischemia were recorded. Cadaveric dissections of 4 cerebellopontine angle (CPA) cisterns with focus on the anterior inferior cerebellar artery (AICA) microvascular were also performed to identify candidate vessels and potential etiology. RESULTS: Fifty-four of 258 patients had an MRI within 14 days of VSS. Retrosigmoid approach was used in 61.1% of patients, translabyrinthine approach in 25.9%, and middle fossa approach in 13.0%. Four patients (7.4%) had acute microvascular ischemia involving the middle cerebellar peduncle (MCP) adjacent to the cranial nerve (CN) VII-VIII complex demonstrated on postoperative MRI. A statistically significant association was found between the translabyrinthine approach and acute brainstem ischemia (odds ratio, 10.6; 95% confidence interval, 1.004-112.7). Dissection of CPAs revealed 10-20 perforating arteries per specimen originating from the lateral pontine and the flocculopeduncular segments of the AICA. Most microvessels travelled in retrograde fashion along the anteroinferior surface of the CN VII-VIII complex to perforate the cisternal surface of the MCP. No patient had residual or delayed neurologic deficits related to brainstem ischemia at final follow-up. CONCLUSIONS: While effort should be made to preserve perforating vessels, microvascular brainstem ischemia is often asymptomatic and did not lead to permanent neurologic deficits in our series.
OBJECTIVE: To identify a potential microvascular etiology in patients who underwent vestibular schwannoma surgery (VSS) complicated by postoperative microvascular brainstem ischemia. METHODS: Charts were retrospectively reviewed of all patients who had an MRI within 14 days of VSS in years 2005-2016. Patient characteristics, preoperative and postoperative imaging features, clinical course and potential predictors of brainstem ischemia were recorded. Cadaveric dissections of 4 cerebellopontine angle (CPA) cisterns with focus on the anterior inferior cerebellar artery (AICA) microvascular were also performed to identify candidate vessels and potential etiology. RESULTS: Fifty-four of 258 patients had an MRI within 14 days of VSS. Retrosigmoid approach was used in 61.1% of patients, translabyrinthine approach in 25.9%, and middle fossa approach in 13.0%. Four patients (7.4%) had acute microvascular ischemia involving the middle cerebellar peduncle (MCP) adjacent to the cranial nerve (CN) VII-VIII complex demonstrated on postoperative MRI. A statistically significant association was found between the translabyrinthine approach and acute brainstem ischemia (odds ratio, 10.6; 95% confidence interval, 1.004-112.7). Dissection of CPAs revealed 10-20 perforating arteries per specimen originating from the lateral pontine and the flocculopeduncular segments of the AICA. Most microvessels travelled in retrograde fashion along the anteroinferior surface of the CN VII-VIII complex to perforate the cisternal surface of the MCP. No patient had residual or delayed neurologic deficits related to brainstem ischemia at final follow-up. CONCLUSIONS: While effort should be made to preserve perforating vessels, microvascular brainstem ischemia is often asymptomatic and did not lead to permanent neurologic deficits in our series.
Authors: Tarek Rayan; Ahmed Helal; Christopher S Graffeo; Avital Perry; Lucas P Carlstrom; Colin L W Driscoll; Michael J Link Journal: J Neurol Surg B Skull Base Date: 2021-05-31
Authors: Adam Alaoui-Ismaili; M E Krogager; A S Jakola; L Poulsgaard; W Couldwell; T Mathiesen Journal: Neurosurg Rev Date: 2020-08-08 Impact factor: 3.042