Impact of additional resection on new ischemic lesions and their clinical relevance after intraoperative 3 Tesla MRI in neuro-oncological surgery

Abstract

Intraoperative MRI (ioMRI) has become a frequently used tool to improve maximum safe resection in brain tumor surgery. The usability of intraoperatively acquired diffusion-weighted imaging sequences to predict the extent and clinical relevance of new infarcts has not yet been studied. Furthermore, the question of whether more aggressive surgery after ioMRI leads to more or larger infarcts is of crucial interest for the surgeons’ operative strategy. Retrospective single-center analysis of a prospective registry of procedures from 2013 to 2019 with ioMRI was used. Infarct volumes in ioMRI/poMRI, lesion localization, mRS, and NIHSS were analyzed for each case. A total of 177 individual operations (60% male, mean age 45.5 years old) met the inclusion criteria. In 61% of the procedures, additional resection was performed after ioMRI, which resulted in a significantly higher number of new ischemic lesions postoperatively (p < .001). The development of new or enlarged ischemic areas upon additional resection could also be shown volumetrically (mean volume in ioMRI 0.39 cm3 vs. poMRI 2.97 cm3; p < .001). Despite the surgically induced new infarcts, mRS and NIHSS did not worsen significantly in cases with additional resection. Additionally, new perilesional ischemia in eloquently located tumors was not associated with an impaired neurological outcome. Additional resection after ioMRI leads to new or enlarged ischemic areas. However, these new infarcts do not necessarily result in an impaired neurological outcome, even when in eloquent brain areas.

Failure of diffusion-weighted imaging in intraoperative 3 Tesla MRI to identify hyperacute strokes during glioma surgery

“…Infarction detection based on DWI sequences in an intraoperative setting is a valuable tool for early diagnosis of surgery related complications. Various groups could show that intraoperatively acquired DWI sequences are of sufficient quality to delineate acute ischemic brain injury 11 , 15 . Additionally, numerous studies have shown that thin DWI restrictions, at e.g.…”

“…Additionally, numerous studies have shown that thin DWI restrictions, at e.g. the resection cavity margin, can be frequently delineated in 20–64% of cases postoperatively after tumor resection 14 , 15 , 28 , 29 . While small ischemic areas around the resection cavity are often considered as “normal postoperative changes”, larger surgically induced infarcts harbor the risk of transient or persistent new neurological deficits.…”

“…Infarcts were only included when adjacent to the resection cavity or the surgical approach and subdivided into 4 classes based on their morphology as described previously 15 : (1) point-shaped infarcts; (2) band-shaped infarcts at the resection cavity; (3) sector-shaped infarcts that involve deeper parts of the parenchyma; (4) territorial infarcts 15 . In the case of multiple isolated infarcts, only the highest class was considered.…”

“…In ioMRI, DWI sequences are employed for the early detection of new surgery related infarcts potentially impairing neurological outcome 11 – 14 . Various studies have shown that the quality of intraoperatively acquired DWI sequences is sufficient to delineate new surgery-related ischemic lesions 11 , 15 . Furthermore, the surgeon's decision whether to continue with further tumor resection after ioMRI control has an impact on the development of new or enlarged ischemic areas around the resection cavity 15 .…”

Incidence of ischemic complications and technical nuances of arteries protection for insular gliomas resection.

“…However, postoperative motor de cits remain major concern [4]. Reported rates of glioma surgery-related ischemic strokes range from 21% to 80% [9,26]. Regarding the insular gliomas, the perioperative ischemic incidence and its risk factors remains obscure, and its arteries protection skills also need further exploration.…”