Asleep triple-modality motor mapping for perirolandic gliomas: an update on outcomes.

OBJECTIVE: Maximal safe resection of gliomas near motor pathways is facilitated by intraoperative mapping. Here, the authors review their results with triple-modality asleep motor mapping with motor evoked potentials and bipolar and monopolar stimulation for cortical and subcortical mapping during glioma surgery in an expanded cohort. METHODS: This was a retrospective analysis of patients who underwent resection of a perirolandic glioma near motor pathways. Clinical and neuromonitoring data were extracted from the electronic medical records for review. All patients with new or worsened postoperative motor deficits were followed for at least 6 months. Regression analyses were performed to assess factors associated with a persistent motor deficit. RESULTS: Between January 2018 and December 2021, 160 operations were performed in 151 patients with perirolandic glioma. Sixty-four patients (40%) had preoperative motor deficits, and the median extent of resection was 98%. Overall, patients in 38 cases (23.8%) had new or worse immediate postoperative deficits by discharge, and persistent deficits by 6 months were seen in 6 cases (3.8%), all in patients with high-grade gliomas. There were no new persistent deficits in low-grade glioma patients (0%). The risk factors for a persistent deficit included an insular tumor component (OR 8.6, p = 0.01), preoperative motor weakness (OR 8.1, p = 0.03), intraoperative motor evoked potential (MEP) changes (OR 36.5, p < 0.0001), and peri-resection cavity ischemia (OR 7.5, p = 0.04). Most persistent deficits were attributable to ischemic injury despite structural preservation of the descending motor tracts. For patients with persistent motor deficits, there were 3 cases (50%) in which a change in MEP was noted but subsequent subcortical monopolar stimulation still elicited a response in the corresponding muscle groups, suggesting axonal activation distal to a point of injury. CONCLUSIONS: Asleep triple motor mapping results in a low rate of permanent deficits, especially for low-grade gliomas. Peri-resection cavity ischemia continues to be a significant risk factor for permanent deficit despite maintaining appropriate distance for subcortical tracts based on monopolar feedback.

Reducing complication rates for repeat craniotomies in glioma patients: a single-surgeon experience and comparison with the literature.

BACKGROUND: There is a concern that glioma patients undergoing repeat craniotomies are more prone to complications. The study's goal was to assess if the complication profiles for initial and repeat craniotomies were similar, to determine predictors of complications, and to compare results with those in the literature. METHODS: A retrospective study was conducted of glioma patients (WHO grade II-IV) who underwent either an initial or repeat craniotomy performed by the senior author from 2012 until 2019. Complications were recorded by discharge, 30 days, and 90 days postoperatively. New neurologic deficits were recorded by 90 days postoperatively. Multivariate regression was performed to identify factors associated with complications. A meta-analysis was performed to identify rates of complications based on number of prior craniotomies. RESULTS: Within the cohort of 714 patients, 400 (56%) had no prior craniotomies, 218 (30.5%) had undergone 1 prior craniotomy, and 96 (13.5%) had undergone ≥ 2 prior craniotomies. There were 27 surgical and 10 medical complications in 30 patients (4.2%) and 19 reoperations for complications in 19 patients (2.7%) with no deaths by 90 days. Complications, reoperation rates, and new neurologic deficits did not differ based on number of prior craniotomies. On multivariate analysis, older age (OR1.5, 95%CI 1.0-2.2) and significant leukocytosis due to steroid use (OR12.6, 95%CI 2.5-62.9) were predictors of complications. Complication rates in the cohort were lower than rates reported in the literature. CONCLUSION: Contrary to prior reports in the literature, repeat craniotomies can be as safe as initial operations if surgeons implement best practices.

Resection of supplementary motor area gliomas: revisiting supplementary motor syndrome and the role of the frontal aslant tract.

OBJECTIVE: The supplementary motor area (SMA) is an eloquent region that is frequently a site for glioma, or the region is included in the resection trajectory to deeper lesions. Although the clinical relevance of SMA syndrome has been well described, it is still difficult to predict who will become symptomatic. The object of this study was to define which patients with SMA gliomas would go on to develop a postoperative SMA syndrome. METHODS: The University of California, San Francisco, tumor registry was searched for patients who, between 2010 and 2019, had undergone resection for newly diagnosed supratentorial diffuse glioma (WHO grades II-IV) performed by the senior author and who had at least 3 months of follow-up. Pre- and postoperative MRI studies were reviewed to confirm the tumor was located in the SMA region, and the extent of SMA resection was determined by volumetric assessment. Patient, tumor, and outcome data were collected retrospectively from documents available in the electronic medical record. Tumors were registered to a standard brain atlas to create a frequency heatmap of tumor volumes and resection cavities. RESULTS: During the study period, 56 patients (64.3% male, 35.7% female) underwent resection of a newly diagnosed glioma in the SMA region. Postoperatively, 60.7% developed an SMA syndrome. Although the volume of tumor within the SMA region did not correlate with the development of SMA syndrome, patients with the syndrome had larger resection cavities in the SMA region (25.4% vs 14.2% SMA resection, p = 0.039). The size of the resection cavity in the SMA region did not correlate with the severity of the SMA syndrome. Patients who developed the syndrome had cavities that were located more posteriorly in the SMA region and in the cingulate gyrus. When the frontal aslant tract (FAT) was preserved, 50% of patients developed the SMA syndrome postoperatively, whereas 100% of the patients with disruption of the FAT during surgery developed the SMA syndrome (p = 0.06). Patients with SMA syndrome had longer lengths of stay (5.6 vs 4.1 days, p = 0.027) and were more likely to be discharged to a rehabilitation facility (41.9% vs 0%, p < 0.001). There was no difference in overall survival for newly diagnosed glioblastoma patients with SMA syndrome compared to those without SMA syndrome (1.6 vs 3.0 years, p = 0.33). CONCLUSIONS: For patients with SMA glioma, more extensive resections and resections involving the posterior SMA region and posterior cingulate gyrus increased the likelihood of a postoperative SMA syndrome. Although SMA syndrome occurred in all cases in which the FAT was resected, FAT preservation does not reliably avoid SMA syndrome postoperatively.

Effects of ventricular entry on patient outcome during glioblastoma resection.

OBJECTIVE: Tumor proximity to the ventricle and ventricular entry (VE) during surgery have both been associated with worse prognoses; however, the interaction between these two factors is poorly understood. Given the benefit of maximal tumor resection, it is imperative for surgical planning and technique to know if VE has negative consequences for patient survival and tumor dissemination. METHODS: The University of California, San Francisco tumor registry was searched for patients with newly diagnosed and recurrent supratentorial glioblastoma (GBM) who underwent resection by the senior author between 2013 and 2018. Tumor location with respect to the subventricular zone (SVZ), size, and extent of resection were assessed using pre- and postoperative imaging. VE was determined by postoperative imaging and/or the operative report. RESULTS: In this 200-patient cohort of newly diagnosed and recurrent GBM, 26.5% of patients had VE during resection. Patients with VE were more likely to have preexisting subependymal disease (41.5% vs 15.0%, p < 0.001). Comparing patients with VE to those without VE, there was no difference in the rates of postoperative hydrocephalus (1.9% vs 4.8%, p = 0.36), ventriculoperitoneal shunting (0% vs 3.4%, p = 0.17), pseudomeningoceles (7.5% vs 5.4%, p = 0.58), or subdural hematomas (11.3% vs 3.4%, p = 0.07). Importantly, rates of subsequent leptomeningeal disease (7.5% vs 10.2%, p = 0.57) and distant parenchymal recurrence (17.0% vs 23.1%, p = 0.35) were not different between the groups. Newly diagnosed patients with tumors contacting the SVZ (type I or II) had worse survival than patients with tumors that did not contact the SVZ (type III or IV) (1.27 vs 1.84 years, p = 0.014, HR 1.8, 95% CI 1.08-3.03), but VE was not associated with worse survival in these patients with high-risk SVZ type I and II tumors (1.15 vs 1.68 years, p = 0.151, HR 0.59, 95% CI 0.26-1.34). CONCLUSIONS: VE was well tolerated, with postoperative complications being rare events. There was no increase in leptomeningeal spread or distant parenchymal recurrence in patients with VE. Finally, although survival was worse for patients with preoperative subependymal disease, VE did not change survival for patients with tumors contacting the ventricle. Therefore, VE during GBM resection is not associated with adverse patient outcomes and should be used by surgeons to enhance extent of resection.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: retrospective cohort; evidence: class II.

Surgical management of incidentally discovered low-grade gliomas.

OBJECTIVE: Although most patients with low-grade glioma (LGG) present after a seizure, a small proportion is diagnosed after neuroimaging is performed for a sign or symptom unrelated to the tumor. While these tumors invariably grow, some surgeons argue for a watchful waiting approach. Here, the authors report on their experience in the surgical treatment of patients with incidental LGG (iLGG) and describe the neurological outcomes, survival, and complications. METHODS: Relevant cases were identified from a prospective registry of patients undergoing glioma resection at the University of California, San Francisco, between 1997 and 2019. Cases were considered iLGG when the lesion was noted on imaging performed for a reason unrelated to the tumor. Demographic, clinical, pathological, and imaging data were extracted from the electronic medical record. Tumor volumes, growth, and extent of resection were calculated from pre- and postoperative volumetric FLAIR sequences. RESULTS: One hundred thirteen of 657 (17.2%) first-time resections for LGG were for incidental lesions. The most common reasons for the discovery of an iLGG were headaches (without mass effect, 34.5%) or trauma (16.8%). Incidental tumors were no different from symptomatic lesions in terms of laterality or location, but they were significantly smaller (22.5 vs 57.5 cm3, p < 0.0001). There was no difference in diagnosis between patients with iLGG and those with symptomatic LGG (sLGG), incorporating both molecular and pathological data. The median preoperative observation time for iLGG was 3.1 months (range 1 month-12 years), and there was a median growth rate of 3.9 cm3/year. Complete resection of the FLAIR abnormality was achieved in 57% of patients with incidental lesions but only 23.8% of symptomatic lesions (p < 0.001), and the residual volumes were smaller for iLGGs (2.9 vs 13.5 cm3, p < 0.0001). Overall survival was significantly longer for patients with incidental tumors (median survival not reached for patients with iLGG vs 14.6 years for those with sLGG, p < 0.0001). There was a 4.4% rate of neurological deficits at 6 months. CONCLUSIONS: The authors present the largest cohort of iLGGs. Patient age, tumor location, and molecular genetics were not different between iLGGs and sLGGs. Incidental tumors were smaller, a greater extent of resection could be achieved, and overall survival was improved compared to those for patients with sLGG. Operative morbidity and rates of neurological deficit were acceptably low; thus, the authors advocate upfront surgical intervention aimed at maximal safe resection for these incidentally discovered lesions.

Triple motor mapping: transcranial, bipolar, and monopolar mapping for supratentorial glioma resection adjacent to motor pathways.

OBJECTIVE: Maximal safe resection of gliomas near motor pathways is facilitated by intraoperative mapping. The authors and other groups have described the use of bipolar or monopolar direct stimulation to identify functional tissue, as well as transcranial or transcortical motor evoked potentials (MEPs) to monitor motor pathways. Here, the authors describe their initial experience using all 3 modalities to identify, monitor, and preserve cortical and subcortical motor systems during glioma surgery. METHODS: Intraoperative mapping data were extracted from a prospective registry of glioma resections near motor pathways. Additional demographic, clinical, pathological, and imaging data were extracted from the electronic medical record. All patients with new or worsened postoperative motor deficits were followed for at least 6 months. RESULTS: Between January 2018 and August 2019, 59 operations were performed in 58 patients. Overall, patients in 6 cases (10.2%) had new or worse immediate postoperative deficits. Patients with temporary deficits all had at least Medical Research Council grade 4/5 power. Only 2 patients (3.4%) had permanently worsened deficits after 6 months, both of which were associated with diffusion restriction consistent with ischemia within the corticospinal tract. One patient's deficit improved to 4/5 and the other to 4/5 proximally and 3/5 distally in the lower limb, allowing ambulation following rehabilitation. Subcortical motor pathways were identified in 51 cases (86.4%) with monopolar high-frequency stimulation, but only in 6 patients using bipolar stimulation. Transcranial or cortical MEPs were diminished in only 6 cases, 3 of which had new or worsened deficits, with 1 permanent deficit. Insula location (p = 0.001) and reduction in MEPs (p = 0.01) were the only univariate predictors of new or worsened postoperative deficits. Insula location was the only predictor of permanent deficits (p = 0.046). The median extent of resection was 98.0%. CONCLUSIONS: Asleep triple motor mapping is safe and resulted in a low rate of deficits without compromising the extent of resection.

Molecular characteristics of diffuse lower grade gliomas: what neurosurgeons need to know.

The importance of genomic information in intrinsic brain tumors is highlighted in the World Health Organization (WHO) 2016 classification of gliomas, which now incorporates both phenotype and genotype data to assign a diagnosis. By using genetic markers to both categorize tumors and advise patients on prognosis, this classification system has minimized the risk of tissue sampling error, improved diagnostic accuracy, and reduced inter-rater variability. In the neurosurgical community, it is critical to understand the role genetics plays in tumor biology, what certain mutations mean for the patient's prognosis and adjuvant treatment, and how to interpret the results of sequencing data that are generated following tumor resection. In this review, we examine the critical role of genetics for diagnosis and prognosis and highlight the importance of tumor genetics for neurosurgeons caring for patients with diffuse lower grade gliomas.

Awake glioma surgery: technical evolution and nuances.

INTRODUCTION: Multiple studies have demonstrated that improved extent of resection is associated with longer overall survival for patients with both high and low grade glioma. Awake craniotomy was developed as a technique for maximizing resection whilst preserving neurological function. METHODS: We performed a comprehensive review of the literature describing the history, indications, techniques and outcomes of awake craniotomy for patients with glioma. RESULTS: The technique of awake craniotomy evolved to become an essential tool for resection of glioma. Many perceived contraindications can now be managed. We describe in detail our preferred technique, the testing paradigms utilized, and critically review the literature regarding functional and oncological outcome. CONCLUSIONS: Awake craniotomy with mapping has become the gold standard for safely maximizing extent of resection for tumor in or near eloquent brain. Cortical and subcortical mapping methods have been refined and the technique is associated with an extremely low rate of complications.

The Glioma-Network Interface: A Review of the Relationship Between Glioma Molecular Subtype and Intratumoral Function.

Gliomas are a major cause of morbidity. Direct cortical stimulation mapping offers the ability to identify functional areas within the broader neural network both cortically and subcortically. Since the World Health Organization (WHO) 2016 classification categorized gliomas into molecular subgroups with varied molecular signatures and clinical behavior, it is possible that gliomas may demonstrate rates of functional network integration. We therefore retrospectively reviewed a data registry of 181 patients with dominant hemisphere frontal, parietal, insular, or temporal gliomas. Our goal was to test the hypothesis that WHO glioma histopathology and molecular subtype influences functional language or motor sites identified within the tumor. Intratumoral function as determined by direct cortical and subcortical stimulation mapping was identified at the highest rate in isocitrate dehydrogenase mutant astrocytomas and oligodendrogliomas. Finally, we reviewed the emerging literature exploring the interface between functional neural networks and gliomas. These data shed light on glioma molecular and histological characteristics most commonly associated within intratumoral function.

Reoperation for Recurrent Glioblastoma and Its Association With Survival Benefit.

BACKGROUND: Glioblastoma is the most common and aggressive primary brain tumor. Despite current treatment, recurrence is inevitable. There are no clear guidelines for treatment of recurrent glioblastoma. OBJECTIVE: To investigate factors at initial surgery predictive of reoperation, and the prognostic variables associated with survival, including reoperation for recurrence. METHODS: A retrospective cohort study was performed, including adult patients diagnosed with glioblastoma between January 2010 and December 2013. Student t test and Fisher exact test compared continuous and categorical variables between reoperation and nonreoperation groups. Univariable and Cox regression multivariable analysis was performed. RESULTS: In a cohort of 204 patients with de novo glioblastoma, 49 (24%) received reoperation at recurrence. The median overall survival in the reoperation group was 20.1 months compared with 9.0 months in the nonreoperation group (P = .001). Reoperation was associated with longer overall survival in our total population (hazard ratio, 0.646; 95% confidence interval, 0.543-0.922; P = .016) but subject to selection bias. Subgroup analyses excluding patients unlikely to be considered for reoperation suggested a much less significant effect of reoperation on survival, which warrants further study with larger cohorts. Factors at initial surgery predictive for reoperation were younger age, smaller tumor size, initial extent of resection ≥50%, shorter inpatient stay, and maximal initial adjuvant therapy. When unfavorable patient characteristics are excluded, reoperation is not an independent predictor of survival. CONCLUSION: Patients undergoing reoperation have favorable prognostic characteristics, which may be responsible for the survival difference observed. We recommend that a large clinical registry be developed to better aid consistent and homogenous data collection. ABBREVIATIONS: ECOG, Eastern Cooperative Oncology GroupEOR, extent of resectionIDH-1, isocitrate dehydrogenase 1IP, inpatientMGMT, O-methylguanine methyltransferaseOS, overall survivalPFS, progression-free survivalRMH, Royal Melbourne Hospital.

Legal disputes over informed consent for cosmetic procedures: a descriptive study of negligence claims and complaints in Australia.

BACKGROUND: Plastic surgeons and other doctors who perform cosmetic procedures face relatively high risks of malpractice claims and complaints. In particular, alleged problems with the consent process abound in this area, but little is known about the clinical circumstances of these cases. METHOD: We reviewed 481 malpractice claims and serious health care complaints resolved in Australia between 2002 and 2008 that alleged failures in the informed consent process for cosmetic and other procedures. We identified all "cases" involving cosmetic procedures and reviewed them in-depth. We calculated their frequency, and described the treatments, allegations, and outcomes involved. RESULTS: A total of 16% (77/481) of the legal disputes over informed consent involved cosmetic procedures. In 70% (54/77) of these cases, patients alleged that the doctor failed to disclose risks of a particular complication, in 39% patients claimed that potential lack of benefit was not explained, and in 26% patients allegations centred on the process by which consent was sought. Five treatment types-liposuction, breast augmentation, face/neck lifts, eye/brow lifts, and rhinoplasty/septoplasty-featured in 70% (54/77) of the cases. Scarring (30/77) and the need for reoperation (18/77) were among the most prevalent adverse health outcomes at issue. CONCLUSION: A mix of factors "supercharges" the informed consent process for cosmetic procedures. Doctors who deliver these procedures should take special care to canvas the risks and possible outcomes that matter most to patients.

The role of transcranial Doppler ultrasound monitoring in patients with aneurysmal subarachnoid haemorrhage.

The effect of transcranial Doppler (TCD) ultrasound monitoring of vasospasm on patient management following aneurysmal subarachnoid haemorrhage (aSAH) remains unclear. We reviewed our departmental use of TCD by retrospectively analysing 152 medical records. Results of investigations and management changes, including frequency of neurological monitoring and changes in triple H therapy, were examined. TCD monitoring occurred in 87 patients (57%) by untrained neurosurgical registrars. There was high variability in the number of operators for each patient (over 50% of patients had more than two different operators), insonation protocol and monitoring duration (at least 50% of patients were monitored for fewer than seven days). TCD results influenced management in only 18 (12%) patients, while clinical deterioration or improvement dictated more than 80% of changes in triple H therapy and neurological monitoring. Prospective validation in similar neurosurgical settings is needed to justify continued usage of TCD monitoring. Formal training for operators and a standard monitoring protocol should also be considered to increase TCD utility. Prospective evaluation of TCD at our centre has recently been completed.

When informed consent goes poorly: a descriptive study of medical negligence claims and patient complaints.

OBJECTIVE: To describe the frequency, characteristics, and outcomes of medicolegal disputes over informed consent. DESIGN AND SETTING: Retrospective review and analysis of negligence claims against doctors insured by Avant Mutual Group Limited and complaints lodged with the Office of the Health Services Commissioner of Victoria that alleged failures in the informed consent process and were adjudicated between 1 January 2002 and 31 December 2008. MAIN OUTCOME MEASURES: Case frequency (by medical specialty), type of allegation, type of treatment. RESULTS: A total of 481 cases alleged deficiencies in the informed consent process (218 of 1898 conciliated complaints [11.5%]; 263 of 7846 negligence claims [3.4%]). 57% of these cases were against surgeons. Plastic surgeons experienced dispute rates that were more than twice those of any other specialty or subspecialty group. 92% of cases (442/481) involved surgical procedures and 16% (77/481) involved cosmetic procedures. The primary allegation in 71% of cases was that the clinician failed to mention or properly explain risks of complications. Five treatment types - procedures on reproductive organs (12% of cases), procedures on facial features excluding eyes (12%), prescription medications (8%), eye surgery (7%) and breast surgery (7%) - accounted for 46% of all cases. CONCLUSIONS: The typical dispute over informed consent involves an operation, often cosmetic, and allegations that a particular complication was not properly disclosed. With Australian courts now looking to patient preferences in setting legal standards of care for risk disclosure, medicolegal disputes provide valuable insights for targeting both quality improvement efforts and risk management activities.

Remedies sought and obtained in healthcare complaints.

In the wake of adverse events, injured patients and their families have a complex range of needs and wants. The tort system, even when operating at its best, will inevitably fall far short of addressing them. In Australia and New Zealand, government-run health complaints commissions take a more flexible and expansive approach to providing remedies for patients injured by or disgruntled with care. Unfortunately, survey research has shown that many patients in these systems are dissatisfied with their experience. We hypothesised that an important explanation for this dissatisfaction is an 'expectations gap'; discordance between what complainants want and what they eventually get out of the process. Analysing a sample of complaints relating to informed consent from the Commission in Victoria (Australia's second largest state, with 5.2 million residents), we found evidence of such a gap. One-third (59/189) of complainants who sought restoration received it; 1 in 5 complainants (17/101) who sought correction received assurances that changes had been or would be made to reduce the risk of others suffering a similar harm; and fewer than 1 in 10 (3/37) who sought sanctions saw steps taken to achieve this outcome initiated. We argue that bridging the expectations gap would go far toward improving patient satisfaction with complaints systems, and suggest several ways this might be done.