Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis.

STUDY DESIGN: Mixed-methods approach. OBJECTIVES: Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. METHODS: A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. RESULTS: The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. CONCLUSIONS: ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

A Clinical Practice Guideline for Prevention, Diagnosis and Management of Intraoperative Spinal Cord Injury: Recommendations for Use of Intraoperative Neuromonitoring and for the Use of Preoperative and Intraoperative Protocols for Patients Undergoing Spine Surgery.

STUDY DESIGN: Development of a clinical practice guideline following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) process. OBJECTIVE: The objectives of this study were to develop guidelines that outline the utility of intraoperative neuromonitoring (IONM) to detect intraoperative spinal cord injury (ISCI) among patients undergoing spine surgery, to define a subset of patients undergoing spine surgery at higher risk for ISCI and to develop protocols to prevent, diagnose, and manage ISCI. METHODS: All systematic reviews were performed according to PRISMA standards and registered on PROSPERO. A multidisciplinary, international Guidelines Development Group (GDG) reviewed and discussed the evidence using GRADE protocols. Consensus was defined by 80% agreement among GDG members. A systematic review and diagnostic test accuracy (DTA) meta-analysis was performed to synthesize pooled evidence on the diagnostic accuracy of IONM to detect ISCI among patients undergoing spinal surgery. The IONM modalities evaluated included somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), electromyography (EMG), and multimodal neuromonitoring. Utilizing this knowledge and their clinical experience, the multidisciplinary GDG created recommendations for the use of IONM to identify ISCI in patients undergoing spine surgery. The evidence related to existing care pathways to manage ISCI was summarized and based on this a novel AO Spine-PRAXIS care pathway was created. RESULTS: Our recommendations are as follows: (1) We recommend that intraoperative neurophysiological monitoring be employed for high risk patients undergoing spine surgery, and (2) We suggest that patients at "high risk" for ISCI during spine surgery be proactively identified, that after identification of such patients, multi-disciplinary team discussions be undertaken to manage patients, and that an intraoperative protocol including the use of IONM be implemented. A care pathway for the prevention, diagnosis, and management of ISCI has been developed by the GDG. CONCLUSION: We anticipate that these guidelines will promote the use of IONM to detect and manage ISCI, and promote the use of preoperative and intraoperative checklists by surgeons and other team members for high risk patients undergoing spine surgery. We welcome teams to implement and evaluate the care pathway created by our GDG.

The Impact of Surgeon Experience on Script Concordance Test Scoring.

OBJECTIVE: The Script Concordance Test (SCT) is a test of clinical decision-making that relies on an expert panel to create its scoring key. Existing literature demonstrates the value of specialty-specific experts, but the effect of experience among the expert panel is unknown. The purpose of this study was to explore the role of surgeon experience in SCT scoring. DESIGN: An SCT was administered to 29 general surgery residents and 14 staff surgeons. Staff surgeons were stratified as either junior or senior experts based on years since completing residency training (<15 versus >25 years). The SCT was scored using the full expert panel, the senior panel, the junior panel, and a subgroup junior panel in practice <5 years. A one-way ANOVA was used to compare the scores of first (R1) and fifth (R5) year residents using each scoring scheme. Cognitive interviews were analyzed for differences between junior and senior expert panelist responses. RESULTS: There was no statistically significant difference between the mean score of six R1s and five R5s using the full expert panel (R1 69.08 versus R5 67.06, F1,9 = 0.10, P = 0.76), the junior panel (R1 66.73 versus R5 62.50, F1,9 = 0.35, P = 0.57), or the subgroup panel in practice <5 years (R1 61.07 versus R5 58.79, F1,9 = 0.18, P = 0.75). However, the average score of R1s was significantly lower than R5s when using the senior faculty panel (R1 52.04 versus R5 63.26, F1,9 = 26.90, P = 0.001). Cognitive interview data suggests that some responses of junior experts demonstrate less confidence than those of senior experts. CONCLUSIONS: SCT scores are significantly affected by the responses of the expert panel. Expert differences between first and fifth year residents were only demonstrated when using an expert panel consisting of senior faculty members. Confidence may play a role in the response selections of junior experts. When constructing an SCT expert panel, consideration must be given to the experience of panel members.

Early Midterm Results After Valve Replacement With Contemporary Pericardial Prostheses for Severe Aortic Stenosis.

BACKGROUND: Clinical studies have demonstrated improved gradients after aortic valve replacement with the Trifecta (TR) valve (Abbott Cardiovascular, St Paul, MN) as compared with the Carpentier-Edwards Magna Ease (ME) valve (Edwards Lifesciences, Irvine, CA). Clinical benefits of this strategy have not been demonstrated. METHODS: Patients undergoing aortic valve replacement for severe aortic stenosis with either valve were included. Patients were excluded if they underwent concomitant procedures other than coronary artery bypass grafting. Inverse proportion treatment weighting was used in the analysis. The primary outcome was a composite of cardiac mortality, need for reintervention, and freedom from first congestive heart failure (CHF). Secondary outcomes were all-cause mortality, the composite components, and cumulative CHF admission. Follow-up echocardiograms were assessed in a cohort of patients to assess structural valve degeneration. RESULTS: There were 331 patients in the TR group and 360 patients in the ME group. The TR group had more women (48% vs 32%, P < .001) with smaller roots (left ventricular outflow tract diameter: TR, 2.11 cm; ME, 2.17 cm; P < .001). After weighting there was no significant difference in the composite measure between groups (P > .05). There was no difference in all-cause mortality (hazard ratio, 0.82; 95% confidence interval, 0.42-1.59; P = .56), and 5-year survival was 91.9% in the ME group and 93.4% in the TR group. There was no difference in cardiac death, reintervention, or first onset of CHF or incidence of structural valve degeneration between groups. There was no difference in the rate of admissions for CHF per 100 patients between the 2 valve types (P = .19). CONCLUSIONS: Early hemodynamic benefits have not translated into differences in medium-term clinical outcomes between these 2 valves. Long-term follow-up is necessary.

Exploring the Impact of the Surgical Exploration and Discovery (SEAD) Program on Medical Students' Perceptions of Gender Biases in Surgery: A Mixed-Method Evaluation.

OBJECTIVE: Female representation in surgery is increasing; however, many surgical specialties continue to observe disproportionately fewer females entering their residencies. This study assesses how medical students' gender-based perceptions of surgical careers are impacted by attending the Surgical Exploration and Discovery (SEAD) program, a 2-week, immersive procedural program that offers observerships, mentorship, and workshops across 8 surgical specialties. DESIGN: In this mixed-method prospective cohort study, medical students' awareness, beliefs, and experiences of gender bias in surgery were assessed using a 10-item Gender Bias in Medical Students Assessment-Surgery (GBMSA-S) psychometric survey instrument inspired by the validated Gender Bias in Medical Education Scale (Parker et al., 2016). SETTING: Undergraduate Medical Education, Faculty of Medicine, at the University of Ottawa in Ottawa, Ontario, Canada. PARTICIPANTS: Eighteen first-year medical students in the experimental group (8 male, 10 female) and 18 in the control group (7 male, 11 female). RESULTS: Compared to the control group, SEAD participants had significant changes in agreement with the statements: "surgery is male-dominated," "medical studies are mainly done in males," "gender discrimination is more pronounced in surgery than other medical professions," "consideration of my gender is an important factor in whether or not to pursue surgery as a career," and "I have encountered gender-biased attitudes and/or behaviors among non-physician health care staff" (p < 0.05). Perceptions of gender bias were reduced post-SEAD. Subgroup analysis by gender suggested that the significance of these changing perspectives was due to female participants' responses. SEAD also produced an increase in the level of interest in surgery (p = 0.04). Receptive and authentic dialogue was identified as a critical step toward social inclusivity (n = 11). CONCLUSIONS: Early surgical exposure through SEAD produces a statistically significant increase in surgical interest and reduces certain perceptions of gender bias in surgery, particularly among female medical students.

Aortic Valve Intervention During Aortic Root Surgery in Children: A Systematic Review.

BACKGROUND: Pediatric aortic root dilatation is a life-threatening condition that lacks guidelines for surgical management. We aimed to analyze the data on aortic valve interventions during root surgery to guide decision-making. METHODS: A search was performed of MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and WHO ICTRP. Citations were screened in duplicate and independently to identify randomized controlled trials, cohorts, and case series involving populations aged 0 to 18 years, who received valve-sparing and valve-replacing aortic root surgeries between 1999 and 2019. Outcomes considered included mortality (perioperative, one year, five year), reintervention rates. RESULTS: After duplicate removal, 689 citations were screened through abstract and full text review, identifying five eligible studies. All five were observational studies evaluating valve-sparing procedures. There were 81 patients with a mean study age range of 9.9 to 13.9 years. Both reimplantation (74%) and remodeling (26%) subtypes were done. Range of mean duration of follow-up was 1.2 to 4.4 years. There was no mortality reported until the one-year follow-up period. The long-term mortality rate was calculated as 0.02 per patient-year (95% CI: 0.01-0.05). The long-term reintervention rate was 0.08 per patient-year (95% CI: 0.05-0.13). CONCLUSIONS: There is limited experience on aortic valve intervention during aortic root surgery in children. Single-arm studies on valve-sparing surgeries show excellent survival up to one year. Mortality and reintervention rates increase in the longer term. The small sample size and lack of controlled studies do not allow for direct comparisons between procedure types.

Nanoparticle-mediated binning and profiling of heterogeneous circulating tumor cell subpopulations.

The analysis of circulating tumor cells (CTCs) is an important capability that may lead to new approaches for cancer management. CTC capture devices developed to date isolate a bulk population of CTCs and do not differentiate subpopulations that may have varying phenotypes with different levels of clinical relevance. Here, we present a new device for CTC spatial sorting and profiling that sequesters blood-borne tumor cells with different phenotypes into discrete spatial bins. Validation data are presented showing that cancer cell lines with varying surface expression generate different binning profiles within the device. Working with patient blood samples, we obtain profiles that elucidate the heterogeneity of CTC populations present in cancer patients and also report on the status of CTCs within the epithelial-to-mesenchymal transition (EMT).