Generating operative workflows for vestibular schwannoma resection: a two-stage Delphi consensus in collaboration with British Skull Base Society. Part 1: the retrosigmoid approach

Objective: An operative workflow systematically compartmentalises operations into hierarchal components of phases, steps, instrument, technique errors and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In Part 1 we present a codified operative workflow for the retrosigmoid approach to vestibular schwannoma resection. / Methods: A mixed-method consensus process of literature review, small group Delphi consensus, followed by a national Delphi consensus was performed in collaboration with British Skull Base Society (BSBS). Each Delphi round was repeated until data saturation and over 90% consensus was reached. / Results: Eighteen consultant skull base surgeons (10 neurosurgeons; 8 ENT) with median 17.9 years of experience (IQR 17.5 years) of independent practice participated. There was a 100% response rate across both Delphi rounds. The operative workflow for the retrosigmoid approach contained 3 phases and 40 unique steps: Phase 1: approach and exposure; Phase 2: tumour debulking and excision; Phase 3: closure. For the retrosigmoid approach, technique and event error for each operative step was also described. / Conclusions: We present Part 1 of a national, multi-centre, consensus-derived codified operative workflow for the retrosigmoid and approach to vestibular schwannomas that encompasses phases, steps, instruments, technique errors, and event errors. The codified retrosigmoid approach presented in this manuscript can serve as foundational research for future work, such as operative workflow analysis or neurosurgical simulation and education

CovidNeuroOnc: A UK multicenter, prospective cohort study of the impact of the COVID-19 pandemic on the neuro-oncology service

BackgroundThe COVID-19 pandemic has profoundly affected cancer services. Our objective was to determine the effect of the COVID-19 pandemic on decision making and the resulting outcomes for patients with newly diagnosed or recurrent intracranial tumors.MethodsWe performed a multicenter prospective study of all adult patients discussed in weekly neuro-oncology and skull base multidisciplinary team meetings who had a newly diagnosed or recurrent intracranial (excluding pituitary) tumor between 01 April and 31 May 2020. All patients had at least 30-day follow-up data. Descriptive statistical reporting was used.ResultsThere were 1357 referrals for newly diagnosed or recurrent intracranial tumors across 15 neuro-oncology centers. Of centers with all intracranial tumors, a change in initial management was reported in 8.6% of cases (n = 104/1210). Decisions to change the management plan reduced over time from a peak of 19% referrals at the start of the study to 0% by the end of the study period. Changes in management were reported in 16% (n = 75/466) of cases previously recommended for surgery and 28% of cases previously recommended for chemotherapy (n = 20/72). The reported SARS-CoV-2 infection rate was similar in surgical and non-surgical patients (2.6% vs. 2.4%, P > .9).ConclusionsDisruption to neuro-oncology services in the UK caused by the COVID-19 pandemic was most marked in the first month, affecting all diagnoses. Patients considered for chemotherapy were most affected. In those recommended surgical treatment this was successfully completed. Longer-term outcome data will evaluate oncological treatments received by these patients and overall survival

Identifying the deficiencies of current diagnostic criteria for neurofibromatosis 2 using databases of 2777 individuals with molecular testing

Purpose We have evaluated deficiencies in existing diagnostic criteria for neurofibromatosis 2 (NF2). Methods Two large databases of individuals fulfilling NF2 criteria (n = 1361) and those tested for NF2 variants with criteria short of diagnosis (n = 1416) were interrogated. We assessed the proportions meeting each diagnostic criterion with constitutional or mosaic NF2 variants and the positive predictive value (PPV) with regard to definite diagnosis. Results There was no evidence for usefulness of old criteria “glioma“ or “neurofibroma.” “Ependymoma” had 100% PPV and high levels of confirmed NF2 diagnosis (67.7%). Those with bilateral vestibular schwannoma (VS) alone aged ≥60 years had the lowest confirmation rate (6.6%) and reduced PPV (80%). Siblings as a first-degree relative, without an affected parent, had 0% PPV. All three individuals with unilateral VS and an affected sibling were proven not to have NF2. The biggest overlap was with LZTR1-associated schwannomatosis. In this category, seven individuals with unilateral VS plus ≥2 nondermal schwannomas reduced PPV to 67%. Conclusions The present study confirms important deficiencies in NF2 diagnostic criteria. The term “glioma” should be dropped and replaced by “ependymoma.” Similarly “neurofibroma” should be removed. Dropping “sibling” from first-degree relatives should be considered and testing of LZTR1 should be recommended for unilateral VS