Assessing perioperative complications associated with use of intraoperative magnetic resonance imaging during glioma surgery – a single centre experience with 516 cases

Information-guided Surgery Centered on Intraoperative Magnetic Resonance Imaging Guarantees Surgical Safety with Low Mortality

Neurosurgery is complex surgery that requires a strategy that maximizes the removal of tumors and minimizes complications; thus, a safe environment during surgery should be guaranteed. In this study, we aimed to verify the safety of brain surgery using intraoperative magnetic resonance imaging (iMRI), based on surgical experience since 2000. Thus, we retrospectively examined 2,018 surgical procedures that utilized iMRI performed in the operating room at Tokyo Women's Medical University Hospital between March 2000 and October 2019. As per our data, glioma constituted the majority of the cases (1,711 cases, 84.8%), followed by cavernous hemangioma (61 cases, 3.0%), metastatic brain tumor (37 cases, 1.8%), and meningioma (31 cases, 1.5%). In total, 1,704 patients who underwent glioma removal were analyzed for mortality within 30 days of surgery and for reoperation rates and the underlying causes within 24 hours and 30 days of surgery. As per our analysis, only one death out of all the glioma cases (0.06%) was reported within the 30-day period. Meanwhile, reoperation within 30 days was performed in 37 patients (2.2%) due to postoperative bleeding in 17 patients (1.0%), infection in 12 patients (0.7%), hydrocephalus in 6 patients (0.4%), cerebrospinal fluid (CSF) leakage in 1 patient, and brain edema in 1 patient (0.06%). Of these, 14 cases (0.8%) of reoperation were performed within 24 hours, that is, 13 cases (0.8%) due to postoperative bleeding and 1 case (0.06%) due to acute hydrocephalus. Mortality rate within 30 days was less than 0.1%. Thus, information-guided surgery with iMRI can improve the safety of surgical resections, including those of gliomas.

The impact of 1.5-T intraoperative magnetic resonance imaging in pediatric tumor surgery: Safety, utility, and challenges

Objective

In this study, we present our experience with 1.5-T high-field intraoperative magnetic resonance imaging (ioMRI) for different neuro-oncological procedures in a pediatric population, and we discuss the safety, utility, and challenges of this intraoperative imaging technology.

Methods

A pediatric consecutive-case series of neuro-oncological surgeries performed between February 2020 and May 2022 was analyzed from a prospective ioMRI registry. Patients were divided into four groups according to the surgical procedure: intracranial tumors (group 1), intraspinal tumors (group 2), stereotactic biopsy for unresectable tumors (group 3), and catheter placement for cystic tumors (group 4). The goal of surgery, the volume of residual tumor, preoperative and discharge neurological status, and postoperative complications related to ioMRI were evaluated.

Results

A total of 146 procedures with ioMRI were performed during this period. Of these, 62 were oncology surgeries: 45 in group 1, two in group 2, 10 in group 3, and five in group 4. The mean age of our patients was 8.91 years, with the youngest being 12 months. ioMRI identified residual tumors and prompted further resection in 14% of the cases. The mean time for intraoperative image processing was 54 ± 6 min. There were no intra- or postoperative security incidents related to the use of ioMRI. The reoperation rate in the early postoperative period was 0%.

Conclusion

ioMRI in pediatric neuro-oncology surgery is a safe and reliable tool. Its routine use maximized the extent of tumor resection and did not result in increased neurological deficits or complications in our series. The main limitations included the need for strict safety protocols in a highly complex surgical environment as well as the inherent limitations on certain patient positions with available MR-compatible headrests.

Impact of Intraoperative Magnetic Resonance Imaging (i-MRI) on Surgeon Decision Making and Clinical Outcomes in Cranial Tumor Surgery

Background  Although intraoperative magnetic resonance imaging (iMRI) has an established role in guiding intraoperative extent of resection (EOR) in cranial tumor surgery, the details of how iMRI data are used by the surgeon in the real-time decision-making process is lacking.

Materials and Methods  The authors retrospectively reviewed 40 consecutive patients who underwent cranial tumor resection with the guidance of iMRI. The tumor volumes were measured by volumetric software. Intraoperative and postoperative EOR were calculated and compared. Surgeon preoperative EOR intention, intraoperative EOR assessment, and how iMRI data impacted surgeon decisions were analyzed.

Results  The pathology consisted of 29 gliomas, 8 pituitary tumors, and 3 other tumors. Preoperative surgeon intention called for gross total resection (GTR) in 28 (70%) cases. After resection and before iMRI scanning, GTR was 20 (50.0%) cases based on the surgeon's perception. After iMRI scanning, the results helped identify 19 (47.5%) cases with unexpected results consisting of 5 (12.5%) with unexpected locations of residual tumors and 14 (35%) with unexpected EOR. Additional resection was performed in 24 (60%) cases after iMRI review, including 6 (15%) cases with expected iMRI results. Among 34 cases with postoperative MRI results, iMRI helped improve EOR in 12 (35.3%) cases.

Conclusion  In cranial tumor surgery, the surgeon's preoperative and intraoperative assessment is frequently imprecise. iMRI data serve several purposes, including identifying the presence of residual tumors, providing residual tumor locations, giving spatial relation data of the tumor with nearby eloquent structures, and updating the neuro-navigation system for the final stage of tumor resection.

Standard clinical approaches and emerging modalities for glioblastoma imaging

Glioblastoma (GBM) is the most common primary adult intracranial malignancy and carries a dismal prognosis despite an aggressive multimodal treatment regimen that consists of surgical resection, radiation, and adjuvant chemotherapy. Radiographic evaluation, largely informed by magnetic resonance imaging (MRI), is a critical component of initial diagnosis, surgical planning, and post-treatment monitoring. However, conventional MRI does not provide information regarding tumor microvasculature, necrosis, or neoangiogenesis. In addition, traditional MRI imaging can be further confounded by treatment-related effects such as pseudoprogression, radiation necrosis, and/or pseudoresponse(s) that preclude clinicians from making fully informed decisions when structuring a therapeutic approach. A myriad of novel imaging modalities have been developed to address these deficits. Herein, we provide a clinically oriented review of standard techniques for imaging GBM and highlight emerging technologies utilized in disease characterization and therapeutic development.

Use of intraoperative MRI for resection of intracranial tumors: A nationwide analysis of short-term outcomes

OBJECTIVE

Recent evidence supports the use of intraoperative MRI (iMRI) during resection of intracranial tumors due to its demonstrated efficacy and clinical benefit. Though many single-center investigations have been conducted, larger nationwide outcomes have yet to be characterized.

METHODS

We used the American College of Surgeons National Surgical Quality Improvement Program database to examine baseline characteristics and 30-day postoperative outcomes among patients undergoing craniotomy for tumor resection with and without iMRI. Comparisons between outcomes were accomplished after propensity matching using chi-square tests for categorical variables and Welch two-sample t-tests for continuous variables.

RESULTS

A total of 38,003 patients met inclusion criteria. Of this population, 54 (0.1%) received iMRI, while 37,949 (99.9%) did not receive iMRI. After propensity score matching, the resulting groups consisted of an iMRI group (n = 54) and a matched non-iMRI group (n = 54). Procedures involving iMRI were associated with significantly increased operation length compared to those without (p < 0.01). Length of hospital stay was higher in patients without iMRI, with this difference trending towards significance (p = 0.05) in the unmatched comparison. Patients undergoing craniotomy without iMRI had a higher rate of readmission (p = 0.04). There was no significant difference in occurrence of other adverse events between the two patient groups.

CONCLUSION

Despite increasing operative length, iMRI is not associated with higher infection rate and may have a clinical benefit associated with reducing readmissions and a trend towards reducing inpatient length of stay. Additional nationwide analyses including more iMRI patients would provide further insight into the strength of these findings.

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-05067-9.

Awake Craniotomy Under 3-Tesla Intraoperative Magnetic Resonance Imaging: A Retrospective Descriptive Report and Canadian Institutional Experience

BACKGROUND

The role of high-field 3-Tesla intraoperative magnetic resonance imaging (I-MRI) during awake craniotomy (AC) has not been extensively studied. We report the feasibility and safety of AC during 3-Tesla I-MRI.

METHODS

This retrospective descriptive report compared 3 groups: AC with minimal sedation and I-MRI; I-MRI-guided craniotomy under general anesthesia (GA), and; AC without I-MRI. Perioperative factors, surgical, anesthetic and radiologic complications, and postoperative morbidity and mortality were recorded.

RESULTS

Overall, 85 patients are included in this report. Five of 23 patients (22%) who underwent AC with I-MRI had anesthetic complications (nausea/vomiting and conversion to GA) compared with 3 of 40 (8%) who underwent I-MRI-guided craniotomy under GA (nausea/vomiting during extubation, and arrhythmia). Intraoperative surgical complications (seizures and speech deficits) occurred in 5 patients (22%) who underwent AC and I-MRI, excessive intraoperative bleeding occurred in 2 patients (5%) who had I-MRI-guided craniotomy under GA, and 4 of 22 (18%) patients who underwent AC without I-MRI experienced neurological complications (seizures, motor deficits, and transient loss of consciousness). Eight patients (20%) who had I-MRI with GA had postoperative complications, largely neurological. The duration of surgery and anesthesia were shortest in the group of patients receiving AC without I-MRI. Seventy-three percent of the patients in this group had residual tumor postoperatively compared with 44% and 38% in those having I-MRI with AC or GA, respectively. Patients who underwent I-MRI-guided craniotomy with GA had the highest morbidity (8%) at hospital discharge.

CONCLUSIONS

Our institutional experience suggests that AC under 3-Tesla I-MRI could be an option for glioma resection, although firm conclusions cannot be drawn given the limited and heterogenous nature of our data. Future multicenter trials comparing anesthetic and imaging modalities for glioma resection are recommended.

Intraoperative contrast-enhanced ultrasound for intramedullary spinal neoplasms: patient series

BACKGROUND

Primary intramedullary spinal tumors cause significant morbidity and death. Intraoperative ultrasound as an adjunct for localization and monitoring the extent of resection has not been systematically evaluated in these patients; the effectiveness of intraoperative contrast-enhanced ultrasound (CEUS) remains almost completely unexplored.

OBSERVATIONS

A retrospective case series of patients at a single institution who had consented to the off-label use of intraoperative CEUS was identified. Seven patients with a mean age of 52.8 ± 15.8 years underwent resection of intramedullary tumors assisted by CEUS performed by a single attending neurosurgeon. Histopathological evaluation revealed 3 cases of hemangioblastoma, 1 case of pilocytic astrocytoma, 2 cases of ependymoma, and 1 case of subependymoma. Contrast enhancement correlated with gadolinium enhancement on preoperative magnetic resonance imaging. Intraoperative CEUS facilitated precise lesion localization and myelotomy planning. Dynamic CEUS studies were useful in demonstrating the blood supply to lesions with a dominant vascular pedicle. Regardless of contrast uptake, the differential enhancement between spinal cord tissue and neoplasm assisted in determining interface boundaries.

LESSONS

Intraoperative CEUS constitutes a useful adjunct for the intraoperative delineation of contrast-enhancing intramedullary tumors and in vivo confirmation of gross-total resection. Systematic investigation is needed to establish the role of CEUS for resection of intramedullary spinal tumors of various pathologies.

Intraoperative MRI-guided Resection in Pediatric Brain Tumor Surgery: A Meta-analysis of Extent of Resection and Safety Outcomes

BACKGROUND

 The objective of this meta-analysis was to analyze the impact of intraoperative magnetic resonance imaging (iMRI) on pediatric brain tumor surgery with regard to the frequency of histopathologic entities, additional resections secondary to iMRI, rate of gross total resections (GTR) in glioma surgery, extent of resection (EoR) in supra- and infratentorial compartment, surgical site infections (SSIs), and neurologic outcome after surgery.

METHODS

 MEDLINE/PubMed Service was searched for the terms "intraoperative MRI," "pediatric," "brain," "tumor," "glioma," and "surgery." The review produced 126 potential publications; 11 fulfilled the inclusion criteria, including 584 patients treated with iMRI-guided resections. Studies reporting about patients <18 years, setup of iMRI, surgical workflow, and extent of resection of iMRI-guided glioma resections were included.

RESULTS

 IMRI-guided surgery is mainly used for pediatric low-grade gliomas. The mean rate of GTR in low- and high-grade gliomas was 78.5% (207/254; 95% confidence interval [CI]: 64.6-89.7, p < 0.001). The mean rate of GTR in iMRI-assisted low-grade glioma surgery was 74.3% (35/47; 95% CI: 61.1-85.5, p = 0.759). The rate of SSI in surgery assisted by iMRI was 1.6% (6/482; 95% CI: 0.7-2.9). New onset of transient postoperative neurologic deficits were observed in 37 (33.0%) of 112 patients.

CONCLUSION

 IMRI-guided surgery seems to improve the EoR in pediatric glioma surgery. The rate of SSI and the frequency of new neurologic deficits after IMRI-guided surgery are within the normal range of pediatric neuro-oncologic surgery.

Cost-effectiveness of Intraoperative MRI for Treatment of High-Grade Gliomas

Background Intraoperative MRI has been shown to improve gross-total resection of high-grade glioma. However, to the knowledge of the authors, the cost-effectiveness of intraoperative MRI has not been established. Purpose To construct a clinical decision analysis model for assessing intraoperative MRI in the treatment of high-grade glioma. Materials and Methods An integrated five-state microsimulation model was constructed to follow patients with high-grade glioma. One-hundred-thousand patients treated with intraoperative MRI were compared with 100 000 patients who were treated without intraoperative MRI from initial resection and debulking until death (median age at initial resection, 55 years). After the operation and treatment of complications, patients existed in one of three health states: progression-free survival (PFS), progressive disease, or dead. Patients with recurrence were offered up to two repeated resections. PFS, valuation of health states (utility values), probabilities, and costs were obtained from randomized controlled trials whenever possible. Otherwise, national databases, registries, and nonrandomized trials were used. Uncertainty in model inputs was assessed by using deterministic and probabilistic sensitivity analyses. A health care perspective was used for this analysis. A willingness-to-pay threshold of $100 000 per quality-adjusted life year (QALY) gained was used to determine cost efficacy. Results Intraoperative MRI yielded an incremental benefit of 0.18 QALYs (1.34 QALYs with intraoperative MRI vs 1.16 QALYs without) at an incremental cost of $13 447 ($176 460 with intraoperative MRI vs $163 013 without) in microsimulation modeling, resulting in an incremental cost-effectiveness ratio of $76 442 per QALY. Because of parameter distributions, probabilistic sensitivity analysis demonstrated that intraoperative MRI had a 99.5% chance of cost-effectiveness at a willingness-to-pay threshold of $100 000 per QALY. Conclusion Intraoperative MRI is likely to be a cost-effective modality in the treatment of high-grade glioma. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Bettmann in this issue.

Anesthetic challenges and outcomes for procedures in the intraoperative magnetic resonance imaging suite: A systematic review

BACKGROUND AND OBJECTIVE

Hybrid operating room suites with intraoperative magnetic resonance imaging enable image guided surgery in a fully functional operating room environment. While this environment creates challenges to anesthetic care, the effects on anesthetic adverse events and outcomes are largely unknown. This systematic scoping review aims to map the existing knowledge about anesthetic care in advanced imaging hybrid operating rooms.

METHODS

A broad-based literature search was performed using the PubMed (Medline), Embase, Cochrane Library, Web of Science, and Google Scholar databases. References published in English between January 1994 and August 2017 were included. Quality of evidence was assessed using the GRADE guidelines.

RESULTS

Forty-seven manuscripts were eligible for data collection. Adverse events were heterogeneously defined across 17 manuscripts and occurred in 0 to 100% (quality of evidence mostly very low). Monitoring difficulty was reported in 4 manuscripts of very low data quality. Interference between the magnet and the electrocardiogram was investigated in 2 manuscripts (quality of evidence low and very low, respectively). None of the reported events appeared to result in long-term patient harm. Author recommendations or a narrative review of the literature were provided in 40 manuscripts. Common safety concerns included lower equipment reliability, inaccessibility of the patient and airway, and the relative isolation of the suite (in relationship to other anesthesia care areas). Most authors also emphasized the importance of safety checklists, protocols, and provider training.

DISCUSSION

While intraoperative magnetic resonance imaging hybrid operating rooms are increasingly utilized, the existing literature does not allow estimating adverse event rates in this location. Prospective studies quantifying the effect of the environment on anesthesia outcomes are lacking. Despite this, there is a broad consensus regarding the anesthetic and safety concerns. More research is needed to inform practice standards and training requirements for this challenging environment.

The Role of Intraoperative MRI in Awake Neurosurgical Procedures: A Systematic Review

Background: Awake craniotomy for brain tumors remains an important tool in the arsenal of the treating neurosurgeon working in eloquent areas of the brain. Furthermore, with the implementation of intraoperative magnetic resonance imaging (I-MRI), one can afford the luxury of imaging to assess surgical resection of the underlying gross imaging defined neuropathology and the surrounding eloquent areas. Ideally, the combination of I-MRI and awake craniotomy could provide the maximal lesion resection with the least morbidity and mortality. However, more resection with the aid of real time imaging and awake craniotomy techniques might give opposite outcome results. The goal of this systematic review.is to identify the available literature on combined I-MRI and awake craniotomy techniques, to better understand the potential morbidity and mortality associated.

Methods: MEDLINE, EMBASE, and CENTRAL were searched from inception up to December 2016. A total of 10 articles met inclusion in to the review, with a total of 324 adult patients.

Results: All studies showed transient neurological deficits between 2.9 to 76.4%. In regards to persistent morbidity, the mean was ~10% (ranges from zero to 35.3%) with a follow up period between 5 days and 6 months.

Conclusion: The preliminary results of this review also suggest this combined technique may impose acceptable post-operative complication profiles and morbidity. However, this is based on low quality evidence, and is therefore questionable. Further, well-designed future trials with the long-term follow-up are needed to provide various aspects of feasibility and outcome data for this approach.

Method for temporal keyhole lobectomies in resection of low- and high-grade gliomas

OBJECTIVE

The purpose of this study was to describe a method of resecting temporal gliomas through a keyhole lobectomy and to share the results of using this technique.

METHODS

The authors performed a retrospective review of data obtained in all patients in whom the senior author performed resection of temporal gliomas between 2012 and 2015. The authors describe their technique for resecting dominant and nondominant gliomas, using both awake and asleep keyhole craniotomy techniques.

RESULTS

Fifty-two patients were included in the study. Twenty-six patients (50%) had not received prior surgery. Seventeen patients (33%) were diagnosed with WHO Grade II/III tumors, and 35 patients (67%) were diagnosed with a glioblastoma. Thirty tumors were left sided (58%). Thirty procedures (58%) were performed while the patient was awake. The median extent of resection was 95%, and at least 90% of the tumor was resected in 35 cases (67%). Five of 49 patients (10%) with clinical follow-up experienced permanent deficits, including 3 patients (6%) with hydrocephalus requiring placement of a ventriculoperitoneal shunt and 2 patients (4%) with weakness. Three patients experienced early postoperative anomia, but no patients had a new speech deficit at clinical follow-up.

CONCLUSIONS

The authors provide their experience using a keyhole lobectomy for resecting temporal gliomas. Their data demonstrate the feasibility of using less invasive techniques to safely and aggressively treat these tumors.

Postoperative Neurosurgical Infection Rates After Shared-Resource Intraoperative Magnetic Resonance Imaging: A Single-Center Experience with 195 Cases

OBJECTIVES

To determine the rate of surgical-site infections (SSI) in neurosurgical procedures involving a shared-resource intraoperative magnetic resonance imaging (ioMRI) scanner at a single institution derived from a prospective clinical quality management database.

METHODS

All consecutive neurosurgical procedures that were performed with a high-field, 2-room ioMRI between April 2013 and June 2016 were included (N = 195; 109 craniotomies and 86 endoscopic transsphenoidal procedures). The incidence of SSIs within 3 months after surgery was assessed for both operative groups (craniotomies vs. transsphenoidal approach).

RESULTS

Of the 109 craniotomies, 6 patients developed an SSI (5.5%, 95% confidence interval [CI] 1.2-9.8%), including 1 superficial SSI, 2 cases of bone flap osteitis, 1 intracranial abscess, and 2 cases of meningitis/ventriculitis. Wound revision surgery due to infection was necessary in 4 patients (4%). Of the 86 transsphenoidal skull base surgeries, 6 patients (7.0%, 95% CI 1.5-12.4%) developed an infection, including 2 non-central nervous system intranasal SSIs (3%) and 4 cases of meningitis (5%). Logistic regression analysis revealed that the likelihood of infection significantly decreased with the number of operations in the new operational setting (odds ratio 0.982, 95% CI 0.969-0.995, P = 0.008).

CONCLUSIONS

The use of a shared-resource ioMRI in neurosurgery did not demonstrate increased rates of infection compared with the current available literature. The likelihood of infection decreased with the accumulating number of operations, underlining the importance of surgical staff training after the introduction of a shared-resource ioMRI.