Hotspots of small strokes in glioma surgery: an overlooked risk?

Mini-strokes after awake surgery for glioma resection: are there anesthesia related factors?

INTRODUCTION

Awake surgery is now a common approach for the resection of glioma. One of the surgical complications is mini-stroke which take the form of periresectional small areas of brain ischemic lesions. The main objective of this study is to evaluate the association between factors related to anesthetic management and the risk of mini-stroke, in awake surgery for glioma resection.

METHODS

In this single-center retrospective study, all patients who were operated on, between 2011 and 2022, in awake conditions for a glioma resection, were retrospectively included. The studied anesthetic parameters included hemodynamic variables, fluid intake and urinary output. The primary endpoint was the presence of mini-stroke on a magnetic resonance imaging performed within the first 48 h postoperatively.

RESULTS

A total of 176 surgeries were included. Mini-stroke was present in 120/171 surgeries (70%), with a median volume of 1.2 interquartile range [0.4-2.2] cubic centimeters (cc). In a multivariable analysis, only the per operative urinary output was significantly associated with the incidence of postoperative mini-strokes (adjusted odd-ratio 0.65, 95% confidence interval 0.45-0.94, p = 0.02). No variables related to the anesthetic management were associated with the volume of postoperative mini-strokes. In particular, the time spent below 90% of the baseline systolic blood pressure was not associated with either the risk or the volume of mini-strokes.

CONCLUSION

During awake surgery for glioma resection, among several anesthesia related factors, only the per operative urinary output was associated with the incidence of postoperative mini-stroke.

Laser interstitial thermal therapy for deep-seated perivascular brain tumors is not associated with distal ischemia

PURPOSE

Laser interstitial thermal therapy (LITT) is a minimally invasive cytoreductive treatment option for brain tumors with a risk of vascular injury from catheter placement or thermal energy. This may be of concern with deep-seated tumors that have surrounding end-artery perforators and critical microvasculature. The purpose of this study was to assess the risk of distal ischemia following LITT for deep-seated perivascular brain tumors.

METHODS

A retrospective review of a multi-institution database was used to identify patients who underwent LITT between 2013 and 2022 for tumors located within the insula, thalamus, basal ganglia, and anterior perforated substance. Demographic, clinical and volumetric tumor characteristics were collected. The primary outcome was radiographic evidence of distal ischemia on post-ablation magnetic resonance imaging (MRI).

RESULTS

61 LITT ablations for deep-seated perivascular brain tumors were performed. Of the tumors treated, 24 (39%) were low-grade gliomas, 32 (52%) were high-grade gliomas, and 5 (8%) were metastatic. The principal location included 31 (51%) insular, 14 (23%) thalamic, 13 (21%) basal ganglia, and 3 (5%) anterior perforated substance tumors. The average tumor size was 19.6 cm3 with a mean ablation volume of 11.1 cm3. The median extent of ablation was 92% (IQR 30%, 100%). Two patients developed symptomatic intracerebral hemorrhage after LITT. No patient had radiographic evidence of distal ischemia on post-operative diffusion weighted imaging.

CONCLUSION

We demonstrate that LITT for deep-seated perivascular brain tumors has minimal ischemic risks and is a feasible cytoreductive treatment option for otherwise difficult to access intracranial tumors.

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

Introduction

Insular gliomas have complex anatomy and microvascular supply that make resection difficult. Furthermore, resection of insular glioma is associated with a significant risk of postoperative ischemic complications. Thus, this study aimed to assess the incidence of ischemic complications related to insular glioma resection, determine its risk factors, and describe a single surgeon's experience of artery-preserving tumor resection.

Methods

We enrolled 75 consecutive patients with insular gliomas who underwent transcortical tumor resection. Preoperative and postoperative demographic, clinical, radiological [including diffusion-weighted imaging (DWI)], intraoperative neurophysiological data, and functional outcomes were analyzed. Motor evoked potentials (MEPs) and radiological characteristics like the relationship between the proximal segment of the lateral lenticulostriate arteries (LLSAs) and the tumor, the flat inner edge sign (the inner edge of the insular glioma is well-defined) or obscure inner edge sign, the distance between the lesion and posterior limb of the internal capsule and the invasion of the superior limiting sulcus by the tumor were analyzed. Strategies such as "residual triangle," "basal ganglia outline reappearance," and "sculpting" technique were used to preserve the LLSAs and the main branches of M2 for maximal tumor resection according to the Berger-Sinai classification.

Results

Postoperative DWI showed acute ischemia in 44 patients (58.7%). Moreover, nine patients (12%) had developed new motor deficits, as determined by the treating neurosurgeons. The flat inner edge sign [odds ratio (OR), 0.144; 95% confidence interval (CI), 0.024-0.876) and MEPs (>50%) (OR, 18.182; 95% CI, 3.311-100.00) were significantly associated with postoperative core ischemia, which affected the posterior limb of the internal capsule or corona radiata.

Conclusions

Insular glioma resection was associated with a high incidence of ischemia, as detected by DWI, as well as new motor deficits that were determined by the treating neurosurgeons. Insular glioma patients with obscure inner edge signs and intraoperative MEPs decline >50% had a higher risk of developing core ischemia. With our strategies, maximal safe resection of insular gliomas may be achieved.

Influences on cognitive outcomes in adult patients with gliomas: A systematic review

People with brain tumors, including those previously treated, are commonly affected by a range of neurocognitive impairments involving executive function, memory, attention, and social/emotional functioning. Several factors are postulated to underlie this relationship, but evidence relating to many of these factors is conflicting and does not fully explain the variation in cognitive outcomes seen in the literature and in clinical practice. To address this, we performed a systematic literature review to identify and describe the range of factors that can influence cognitive outcomes in adult patients with gliomas. A literature search was performed of Ovid MEDLINE, PsychINFO, and PsycTESTS from commencement until September 2021. Of 9,998 articles identified through the search strategy, and an additional 39 articles identified through other sources, 142 were included in our review. The results confirmed that multiple factors influence cognitive outcomes in patients with gliomas. The effects of tumor characteristics (including location) and treatments administered are some of the most studied variables but the evidence for these is conflicting, which may be the result of methodological and study population differences. Tumor location and laterality overall appear to influence cognitive outcomes, and detection of such an effect is contingent upon administration of appropriate cognitive tests. Surgery appears to have an overall initial deleterious effect on cognition with a recovery in most cases over several months. A large body of evidence supports the adverse effects of radiotherapy on cognition, but the role of chemotherapy is less clear. To contrast, baseline cognitive status appears to be a consistent factor that influences cognitive outcomes, with worse baseline cognition at diagnosis/pre-treatment correlated with worse long-term outcomes. Similarly, much evidence indicates that anti-epileptic drugs have a negative effect on cognition and genetics also appear to have a role. Evidence regarding the effect of age on cognitive outcomes in glioma patients is conflicting, and there is insufficient evidence for gender and fatigue. Cognitive reserve, brain reserve, socioeconomic status, and several other variables discussed in this review, and their influence on cognition and recovery, have not been well-studied in the context of gliomas and are areas for focus in future research.

Clinical and prognostic implications of rim restriction following glioma surgery

Rim restriction surrounding the resection cavity of glioma is often seen on immediate post-op diffusion-weighted imaging (DWI). The etiology and clinical impact of rim restriction are unknown. We evaluated the incidence, risk factors and clinical consequences of this finding. We evaluated patients that underwent surgery for low-grade glioma (LGG) and glioblastoma (GBM) without stroke on post-operative imaging. Analyses encompassed pre- and postoperative clinical, radiological, intraoperative monitoring, survival, functional and neurocognitive outcomes. Between 2013 and 2017, 63 LGG and 209 GBM patients (272 in total) underwent surgical resection and were included in our cohort. Post-op rim restriction was demonstrated in 68 patients, 32% (n = 20) of LGG and 23% (n = 48) of GBM patients. Risk factors for restriction included temporal tumors in GBM (p = 0.025) and insular tumors in LGG (p = 0.09), including longer surgery duration in LGG (p = 0.008). After a 1-year follow-up, LGG patients operated on their dominant with post-op restriction had a higher rate of speech deficits (46 vs 9%, p = 0.004). Rim restriction on postoperative imaging is associated with longer duration of glioma surgery and potentially linked to brain retraction. It apparently has no direct clinical consequences, but is linked to higher rates of speech deficits in LGG dominant-side surgeries.

Intraoperative risk factors for peritumoral infarctions following glioma surgery

Background

Surgical intraoperative risk factors for peritumoral infarctions are not much studied. In the present study, we explore the possible association between intraoperative factors and infarctions diagnosed from early postoperative MRIs.

Methods

We screened all adult patients operated for newly diagnosed or recurrent diffuse gliomas at out department from December 2015 to October 2020 with available postoperative MRI including DWI sequences. Patient data was prospectively collected in a local tumor registry. Immediately after surgery, the surgeon completed a questionnaire on tumor vascularization, tumor stiffness, delineation of tumor from normal brain tissue, which surgical tool(s) were used, and if they had sacrificed a functional artery or a significant vein.

Results

Data from 175 operations were included for analysis. Of these, 66 cases (38%) had postoperative peritumoral infarctions. 24 (36%) were rim-shaped and 42 (64%) infarctions were sector-shaped. The median infarction volume was 2.4 ​cm³. Surgeon reported sacrifice of a significant vein was associated with infarctions, but we found no clear “dose-response”, as “perhaps” was associated with fewer infarctions than “no”. None of the other studied factors reached statistical significance. However, there was a trend for more infarctions when an ultrasonic aspirator was used for tumor resection. Subgroup analyses were done for rim-shaped and sector-shaped infarctions, and ultrasonic aspirator was associated with sector-shaped infarctions (p ​= ​0.032). Infarction rates differed across surgeons (range 15%–67%), p ​= ​0.021).

Conclusion

In this single center study, no clear relationships between surgeon reported intraoperative factors and postoperative infarctions were observed. Still, risks seem to be surgeon dependent.

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Data on intraoperative factors from 175 operations for diffuse gliomas were assessed.

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No clear relationships between surgeon reported intraoperative factors and postoperative infarctions were observed.

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Risks of infarctions seems to be surgeon dependent.

Surgery of Insular Diffuse Gliomas-Part 1: Transcortical Awake Resection Is Safe and Independently Improves Overall Survival

BACKGROUND

Insular diffuse glioma resection is at risk of vascular injury and of postoperative new neurocognitive deficits.

OBJECTIVE

To assess safety and efficacy of surgical management of insular diffuse gliomas.

METHODS

Observational, retrospective, single-institution cohort analysis (2005-2019) of 149 adult patients surgically treated for an insular diffuse glioma: transcortical awake resection with intraoperative functional mapping (awake resection subgroup, n = 61), transcortical asleep resection without functional mapping (asleep resection subgroup, n = 50), and stereotactic biopsy (biopsy subgroup, n = 38). All cases were histopathologically assessed according to the 2016 World Health Organization classification and cIMPACT-NOW update 3.

RESULTS

Following awake resection, 3/61 patients had permanent motor deficit, seizure control rates improved (89% vs 69% preoperatively, P = .034), and neurocognitive performance improved from 5% to 24% in tested domains, despite adjuvant oncological treatments. Resection rates were higher in the awake resection subgroup (median 94%) than in the asleep resection subgroup (median 46%; P < .001). There was more gross total resection (25% vs 12%) and less partial resection (34% vs 80%) in the awake resection subgroup than in the asleep resection subgroup (P < .001). Karnofsky Performance Status score <70 (adjusted hazard ratio [aHR] 2.74, P = .031), awake resection (aHR 0.21, P = .031), isocitrate dehydrogenase (IDH)-mutant grade 2 astrocytoma (aHR 5.17, P = .003), IDH-mutant grade 3 astrocytoma (aHR 6.11, P < .001), IDH-mutant grade 4 astrocytoma (aHR 13.36, P = .008), and IDH-wild-type glioblastoma (aHR 21.84, P < .001) were independent predictors of overall survival.

CONCLUSION

Awake surgery preserving the brain connectivity is safe, allows larger resections for insular diffuse gliomas than asleep resection, and positively impacts overall survival.

Insular lobe surgery and cognitive impairment in gliomas operated with intraoperative neurophysiological monitoring

BACKGROUND

For a long time, surgery of insular gliomas was considered at high risk for postoperative cognitive deficits, but recent studies highlighted the feasibility of the surgical approach. The aims of our study were to investigate the presence of language impairment before and after surgery and the relationship between language impairment and tumor volume preoperatively and extent of resection (EOR) 3 months after surgery.

METHODS

Thirty-five patients with insular gliomas underwent an extensive language assessment before and few days after surgery, and after 3 months. Intraoperative neurophysiological monitoring (IOM) and brain mapping with direct electrical stimulation (DES) were used in all the cases; 8 patients underwent awake craniotomy. Statistical analysis was performed on the language tests administered.

RESULTS

Patients with pure left insular lesion showed language impairment before and after surgery. Overall, patients with a left lesion showed a drop of performance after surgery followed by a partial recovery. Moreover, when the tumor involved the insula and adjacent networks, we observed a more severe deficit. No correlations were found between tumor volume, EOR, and language impairment.

CONCLUSIONS

Left insular lobe is an important hub in language networks; its involvement determines pre- and postsurgical deficits, together with the involvement of white matter connections. Tumor volume and EOR are not risk factors per se directly related to language functioning. Surgery of insular gliomas is possible with a pre- and intraoperative extensive study of the patient with IOM and awake surgery, and encouraged by the trend of cognitive recovery highlighted.

Incidence and impact of stroke following surgery for low-grade gliomas

OBJECTIVE

Ischemic complications are a common cause of neurological deficits following low-grade glioma (LGG) surgeries. In this study, the authors evaluated the incidence, risk factors, and long-term implications of intraoperative ischemic events.

METHODS

The authors retrospectively evaluated patients who had undergone resection of an LGG between 2013 and 2017. Analysis included pre- and postoperative demographic, clinical, radiological, and anesthetic data, as well as intraoperative neurophysiology data, overall survival, and functional and neurocognitive outcomes.

RESULTS

Among the 82 patients included in the study, postoperative diffusion-weighted imaging showed evidence of acute ischemic strokes in 19 patients (23%), 13 of whom (68%) developed new neurological deficits. Infarcts were more common in recurrent and insular surgeries (p < 0.05). Survival was similar between the patients with and without infarcts. Immediately after surgery, 27% of the patients without infarcts and 58% of those with infarcts experienced motor deficits (p = 0.024), decreasing to 16% (p = 0.082) and 37% (p = 0.024), respectively, at 1 year. Neurocognitive functions before and 3 months after surgery were generally stable for the two groups, with the exception of a decline in verbal rhyming ability among patients with infarcts. Confusion during awake craniotomy was a strong predictor of the occurrence of an ischemic stroke. Mean arterial pressure at the beginning of surgery was significantly lower in the infarct group.

CONCLUSIONS

Recurrent surgeries and insular tumor locations are risk factors for intraoperative strokes. Although they do not affect survival, these strokes negatively affect patient activity and performance status, mainly during the first 3 postoperative months, with gradual functional improvement over 1 year. Several intraoperative parameters may suggest the impending development of an infarct.

Impaired neurocognitive function in glioma patients: from pathophysiology to novel intervention strategies

PURPOSE OF REVIEW

This review succinctly summarizes the recent literature regarding etiological contributors to impaired neurocognitive function (NCF) in adult patients with glioma. A brief overview of intervention and prevention strategies is also provided.

RECENT FINDINGS

A majority of patients with glioma exhibit NCF deficits, most frequently in memory and executive functioning. Impairments are often disabling and associated with reduced quality of life and survival. Cause is multifactorial and includes the tumour itself, treatments received and associated comorbidities. Although modern techniques such as brain mapping, dosing modifications and prophylactic medication aim to improve the NCF outcomes following neurosurgical resection and radiation therapy, a sizeable proportion of patients continue to evidence treatment-related NCF declines related to adverse effects to both local and distributed cerebral networks. Numerous patient and tumour characteristics, including genetic markers and sociodemographic factors, influence the pattern and severity of NCF impairment. Some rehabilitative and pharmacologic approaches show promise in mitigating NCF impairment in this population, though benefits are somewhat modest and larger scale intervention studies are needed.

SUMMARY

Research regarding NCF in patients with glioma has dramatically proliferated, providing insights into the mechanisms underlying impaired NCF and pointing to potential interventions, though further work is needed.