Faculty Bibliography

Complete surgical cytoreduction (R0 resection) is the single most important prognosticator in epithelial ovarian cancer (EOC). Explainable Artificial Intelligence (XAI) could clarify the influence of static and real-time features in the R0 resection prediction. We aimed to develop an AI-based predictive model for the R0 resection outcome, apply a methodology to explain the prediction, and evaluate the interpretability by analysing feature interactions. The retrospective cohort finally assessed 571 consecutive advanced-stage EOC patients who underwent cytoreductive surgery. An eXtreme Gradient Boosting (XGBoost) algorithm was employed to develop the predictive model including mostly patient- and surgery-specific variables. The Shapley Additive explanations (SHAP) framework was used to provide global and local explainability for the predictive model. The XGBoost accurately predicted R0 resection (area under curve [AUC] = 0.866; 95% confidence interval [CI] = 0.8−0.93). We identified “turning points” that increased the probability of complete cytoreduction including Intraoperative Mapping of Ovarian Cancer Score and Peritoneal Carcinomatosis Index < 4 and <5, respectively, followed by Surgical Complexity Score > 4, patient’s age < 60 years, and largest tumour bulk < 5 cm in a surgical environment of optimized infrastructural support. We demonstrated high model accuracy for the R0 resection prediction in EOC patients and provided novel global and local feature explainability that can be used for quality control and internal audit.

The ability to accurately and precisely measure the thickness of biomaterial constructs is critical for characterizing both specific dimensional features and related mechanical properties. However, in the absence of a standardized approach for thickness measurements, a variety of imaging modalities have been employed, which have been associated with varying limits of accuracy, particularly for ultrathin hydrated structures. Electron microscopy (EM), a commonly used modality, yields thickness values for extensively processed and nonhydrated constructs, potentially resulting in overestimated mechanical properties, including elastic modulus and ultimate tensile strength. Confocal laser scanning microscopy (CLSM) has often been used as a nondestructive imaging alternative. However, published CLSM-derived image analysis protocols use arbitrary signal intensity cutoffs and provide minimal information regarding thickness variability across imaged surfaces. To address the aforementioned limitations, we present a standardized, user-independent CLSM image acquisition and analysis approach developed as a custom ImageJ macro and validated with collagen-based scaffolds. In the process, we also quantify thickness discrepancies in collagen-based scaffolds between CLSM and EM techniques, further illustrating the need for improved strategies. Employing the same image acquisition protocol, we also demonstrate that this approach can be used to estimate the surface roughness of the same scaffolds without the use of specialized instrumentation.

BACKGROUND:Preventable morbidity and mortality among emergency surgery patients is not adequately analyzed. We aim to describe and classify preventable complications and deaths in this population. METHODS:The medical records and quality control documents of patients with emergency, non-trauma, surgical disease admitted between September 1, 2006, and August 31, 2018, and recorded to have a preventable or potentially preventable morbidity and mortality were reviewed. The primary outcome was a classification of the complications and deaths by a panel of experts, as attributable to issues of personal performance or system deficiencies. RESULTS:One hundred and fifty patients were identified (127 complications and 23 deaths). The most commonly encountered preventable complications were surgical-site infection (17%), bleeding (13%), injury to adjacent structures (12%), and anastomotic leak (8%). The majority of complications seemed to stem from personal performance (97%), due to either technical or judgment issues, and only 3% were linked with system flaws, either in the form of communication or inadequate protocols. Alcohol use disorder and duration of operation were different between patients with preventable adverse events related to technical issues and patients related to judgment issues; furthermore, more patients who experienced judgment issues died during hospital stay (p <0.05). CONCLUSION/CONCLUSIONS:Among emergency surgery patients, who suffer preventable complications and deaths, issues related to personal performance are more frequent than system flaws. Whereas the effort to improve systems should be unwavering, the emphasis on the surgeon's personal responsibility to avoid preventable complications should not be derailed.

The multiscale organization of protein-based fibrillar materials is a hallmark of many organs, but the recapitulation of hierarchal structures down to fibrillar scales, which is a requirement for withstanding physiological loading forces, has been challenging. We present a microfluidic strategy for the continuous, large-scale formation of strong, handleable, free-standing, multicentimeter-wide collagen sheets of unprecedented thinness through the application of hydrodynamic focusing with the simultaneous imposition of strain. Sheets as thin as 1.9 μm displayed tensile strengths of 0.5-2.7 MPa, Young's moduli of 3-36 MPa, and modulated the diffusion of molecules as a function of collagen nanoscale structure. Smooth muscle cells cultured on engineered sheets oriented in the direction of aligned collagen fibrils and generated coordinated vasomotor responses. The described biofabrication approach enables rapid formation of ultrathin collagen sheets that withstand physiologically relevant loads for applications in tissue engineering and regenerative medicine, as well as in organ-on-chip and biohybrid devices.

INTRODUCTION:Anemia's effect on head and neck surgical complications is unknown. METHODS:Head and neck cancer operations were acquired from the 2006 to 2013 American College of Surgeons National Surgical Quality Improvement Program databases. Anemia was defined as <39% or <36% hematocrit in men and women, respectively. Multivariable logistic regression analyses were performed. RESULTS:Major head and neck surgery patients had a 44.2% anemia incidence (n = 527 of 1193). Anemic patients had increased complication rates (27.1%) and mortality (2.1%) vs non-anemic patients at 19.8% (P = .003) and 0.5% (P = .009), respectively. There was a significant difference in morbidity odds with hematocrit >27% (odds ratio [OR] = 1.09) vs <27% (OR = 4.22). Complication odds were further increased with hematocrit between 24% and 27% (OR = 8.94). There were increased rates of wound dehiscence (6.6% vs 2.7%, P < .001), pneumonia (8.5% vs 4.7%, P = .006), and myocardial infarction (1.7% vs 0.3%, P = .01) in anemic vs non-anemic patients. CONCLUSION:Anemia was associated with increased morbidity at hematocrit <27%. An inverse dose-dependent effect of decreasing hematocrit was observed for overall morbidity.

PURPOSE/OBJECTIVE:Bilateral mastectomy (BM) is traditionally performed using a single-surgeon (SS) technique (SST); a co-surgeon (CS) technique (CST), where each attending surgeon concurrently performs a unilateral mastectomy, offers an alternative approach. We sought to compare the CST and SST for BM with respect to operative times and complications. METHODS:Patients undergoing BM without reconstruction at our institution between 2005 and 2015 were identified using operative caselogs and stratified into CS- and SS-cohorts. Operative time (OT; incision to closure) was calculated. Patient age, cancer presence/stage, hormone receptor/BRCA status, breast weight, axillary procedure, and 30-day complications were extracted. Differences in OT, complications, and demographics between cohorts were assessed with t tests and Chi-square tests. A multivariate linear regression model was fit to identify factors independently associated with OT. RESULTS:Overall, 109 BM cases were identified (CS, n = 58 [53.2%]; SS, n = 51 [46.8%]). Average duration was significantly shorter for the CST by 33 min (21.6% reduction; CS: 120 min vs. SS: 153 min, p < 0.001), with no difference in complication rates (p = 0.65). Demographic characteristics did not differ between cohorts except for total breast weight (TBW) (CS: 1878 g vs. SS: 1452 g, p < 0.05). Adjusting for TBW, CST resulted in a 27.8% reduction in OT (44-min savings, p < 0.001) compared to SST. CONCLUSIONS:The CST significantly reduces OT for BM procedures compared to the SST without increasing complication rates. While time-savings was < 50% and may not be ideal for every patient, the CST offers an alternative BM approach potentially best-suited for large TBW patients and those undergoing axillary procedures.