Management of peripheral nerve sheath tumors: 17 years of experience at Toronto Western Hospital

OBJECTIVEA surgical series of 201 benign and malignant peripheral nerve sheath tumors (PNSTs) was assessed to characterize the anatomical and clinical presentation of tumors and identify predictors of neurological outcome, recurrence, and extent of resection.METHODSAll surgically treated PNSTs from the Division of Neurosurgery at Toronto Western Hospital from 1993 to 2010 were reviewed retrospectively. Data were collected on patient demographics, clinical presentation, surgical technique, extent of resection, postoperative neurological outcomes, and recurrence.RESULTSOne hundred seventy-five patients with 201 tumors had adequate follow-up for analysis. There were 182 benign and 19 malignant PNSTs. Of the benign lesions, 133 were schwannomas, 21 of which were associated with a diagnosis of schwannomatosis. There were 49 neurofibromas, and 26 were associated with neurofibromatosis Type 1 (NF1). Patients presenting with schwannomas were significantly older than those with neurofibromas. Schwannomas were more readily resected than neurofibromas, with the extent of resection of the former influenced by tumor location. Patients with benign PNSTs typically presented with a painful mass and less frequently with motor deficits. The likelihood of worsened postoperative motor function was decreased in patients with fully resected tumors or preoperative deficits. Recurrence of schwannomas and neurofibromas were seen more frequently in patients diagnosed with NF3 and NF1, respectively. Subtotal resection was associated with the increased recurrence of all benign lesions.CONCLUSIONSOutcomes following resection of benign PNSTs depend on tumor histopathology, tumor location, and genetic predisposition syndrome. Gross-total resection should be attempted for benign lesions where possible. The management of malignant PNSTs remains challenging, requiring a multimodal approach.

Transient Neurologic Symptoms following Spinal Anesthesia with Isobaric Mepivacaine: A Decade of Experience at Toronto Western Hospital

Background. Transient neurologic symptoms (TNSs) can be distressing for patients and providers following uneventful spinal anesthesia. Spinal mepivacaine may be less commonly associated with TNS than lidocaine; however, reported rates of TNS with intrathecal mepivacaine vary considerably. Materials and Methods. We conducted a retrospective cohort study reviewing the internal medical records of surgical patients who underwent mepivacaine spinal anesthesia at Toronto Western Hospital over the last decade to determine the rate of TNS. We defined TNS as new onset back pain that radiated to the buttocks or legs bilaterally. Results. We found one documented occurrence of TNS among a total of 679 mepivacaine spinal anesthetics (0.14%; CI: 0.02–1.04%) that were performed in 654 patients. Conclusion. Our retrospective data suggest that the rate of TNS associated with mepivacaine spinal anesthesia is lower than that previously reported in the literature.

F.10 Management of peripheral nerve sheath tumours: the Toronto Western Hospital experience

Background: We retrospectively review benign peripheral nerve sheath tumours (BPNST) managed surgically at the Toronto Western Hospital. The incidence of BPNST is classified by anatomic location and predisposition syndrome. Independent predictors of tumour recurrence and symptom resolution are identified. Methods: 175 patients with 201 tumours were eligible for analysis. Data was collected on patient age, gender, diagnosis of neurofibromatosis (NF), tumour histopathology, tumour location, tumour volume, and extent of resection. Postoperative motor, sensory and pain outcomes were dichotomized as stable/improved or worse than preoperative scores. Relationships between tumour recurrence, or symptom resolution, and predictor variables were assessed with univariate and multiple logistic regression models. Results: Among Schwannomas, subtotal resection, a diagnosis of Schwannomatosis, and larger tumour volume were associated with recurrence (p=0.012, p=0.048, p=0.049, respectively); for neurofibromas, subtotal resection and a diagnosis of NF1 were associated with recurrence (p=0.036, p=0.022, respectively). Multivariate analyses revealed subtotal resection as an independent predictor of recurrence for BPNSTs (p=0.007, OR=13.16, 95%-CI 2.34-52.63). Gross-total resection (p=0.023, OR=4.01, 95%-CI 1.21-13.22) and presence of a preoperative motor deficit (p=0.038, OR=8.06, 95%-CI 4.65-90.91) were independent predictors of stable/improved postoperative motor function for BPNSTs. Conclusions: Gross-total resection is associated with both reduced recurrence and improved postoperative motor function, and should be attempted for all eligible BPNSTs.

Predictors of Surgical Candidacy in 414 Epilepsy Patients Admitted to the EMU

Objectives:Admission to an Epilepsy Monitoring Unit (EMU) is essential for pre-surgical evaluation of patients with medically-refractory epilepsy; however, prolonged referral times and resource limitations are significant access barriers. Therefore, identification of pre-EMU variables that predict potential surgical candidates can assist in the triage of patient admissions to the EMU.Methods:In this hypothesis-generating study, a retrospective analysis of patients admitted for pre-surgical evaluation to the Toronto Western Hospital EMU (2004-2011) was performed. Univariate and multivariate logistic regression was used to identify variables that could independently predict subsequent surgical candidacy following EMU evaluation.Results:Four hundred and fourteen patients were admitted to the EMU. Overall, 259 patients (62.5%) were identified as potential surgical candidates. One hundred and seven patients (25.8%) required invasive electroencephalogram (iEEG) implantations; of 75 patients consenting to iEEG analysis 39 underwent a subsequent resective procedure. Male patients and those with a lesion on MRI were 1.9 times more likely to be surgical candidates (95% CI 1.18-2.98 and 0.94-3.80, respectively), while patients with non-localizable seizures were seven times less likely (95% CI 0.02-1.25).Conclusion:In this retrospective, hypothesis-generating study male gender, presence of a lesion on MRI and localizable seizures on routine outpatient EEG analysis independently predicted subsequent resective epilepsy surgical candidacy in EMU patients. Upon validation by other studies, these variables may be considered by clinicians referring patients to the EMU in order to improve wait times and optimize patient care.

Analysis of Complaints to a Tertiary Care Pain Clinic Over a Nine-Year Period

BACKGROUND: The present study is the result of an internal audit and examines the profiles of complainants and the sources and nature of complaints toward the staff in a tertiary care pain clinic, the Comprehensive Pain Program of the Toronto Western Hospital in Toronto, Ontario.METHODS: All sources of complaints over a nine-year period were reviewed, which included the following: Toronto Western Hospital Patient Relations (PR) records, with a subset of the files qualitatively analyzed in depth regarding the nature of complaints and complainants; complaints that bypassed PR and were addressed directly to the program director against members of the staff; complaints to the College of Physicians and Surgeons of Ontario; and complaints recorded anonymously at rateMDs.com.RESULTS: Although the prevalence of PR complaints was very low (1.73 complaints per 1000 visits), several other sources of complaints were identified. The typical complainant was a Canadian-born woman acting on her behalf or on behalf of a family member. More than one-half of the complaints were directed against the physicians regarding their opinion of psychological factors augmenting the patient’s presentation and/or inappropriate use of opioids. Defensive techniques instituted by the Comprehensive Pain Program staff in reaction to the complaints are discussed, and pertinent literature is reviewed.CONCLUSION: The present study is the first to examine the nature of complaints and complainants from a Canadian pain clinic. Further studies are needed to explore the complex issues of patient and staff interactions, and complaints in the era of ‘patient-centred care’.