Validity of task-specific metrics for assessment in perineal proctectomy.

BACKGROUND: Perineal proctectomy is a complex procedure that requires advanced skills. Currently, there are no simulators for training in this procedure. As part of our objective of developing a virtual reality simulator, our goal was to develop and validate task-specific metrics for the assessment of performance for this procedure. We conducted a three-phase study to establish task-specific metrics, obtain expert consensus on the appropriateness of the developed metrics, and establish the discriminant validity of the developed metrics. METHODS: In phase I, we utilized hierarchical task analysis to formulate the metrics. In phase II, a survey involving expert colorectal surgeons determined the significance of the developed metrics. Phase III was aimed at establishing the discriminant validity for novices (PGY1-3) and experts (PGY4-5 and faculty). They performed a perineal proctectomy on a rectal prolapse model. Video recordings were independently assessed by two raters using global ratings and task-specific metrics for the procedure. Total scores for both metrics were computed and analyzed using the Kruskal-Wallis test. A Mann-Whitney U test with Benjamini-Hochberg correction was used to evaluate between-group differences. Spearman's rank correlation coefficient was computed to assess the correlation between global and task-specific scores. RESULTS: In phase II, a total of 23 colorectal surgeons were recruited and consensus was obtained on all the task-specific metrics. In phase III, participants (n = 22) included novices (n = 15) and experts (n = 7). There was a strong positive correlation between the global and task-specific scores (rs = 0.86; P < 0.001). Significant between-group differences were detected for both global (χ2 = 15.38; P < 0.001; df = 2) and task-specific (χ2 = 11.38; P = 0.003; df = 2) scores. CONCLUSIONS: Using a biotissue rectal prolapse model, this study documented high IRR and significant discriminant validity evidence in support of video-based assessment using task-specific metrics.

Outcomes following Lower Extremity Amputation in Patients with Diabetes Mellitus and Peripheral Arterial Disease.

BACKGROUND: Lower extremity amputations (LEAs) are projected to increase drastically in the United States. The potential effects of diabetes mellitus (DM) and peripheral arterial disease (PAD) on LEA outcomes have not been well-explored. We sought to investigate the clinical outcomes of LEA in patients with DM alone, PAD alone, and patients with concurrent DM and PAD (DM + PAD) from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample. METHODS: Adult patients (≥18 years) undergoing LEA in 2007-2011 based on ICD-9 procedure codes were selected. Patient morbidity, and mortality were assessed utilizing logistic and linear regression. Multivariable analyses adjusted for additional patient and hospital characteristics. RESULTS: A total of 62,291 LEAs were identified between 2007 and 2011. The mean (SD) age was 66.4 (13.7) years. Patients were predominantly Caucasian (56.4%), male (62.9%), and admitted as an emergency admission (44.1%). A higher incidence of LEA was observed in patients with DM + PAD (47.3%) than those with either DM alone (26.4%) or PAD alone (26.3%). On adjustment for patient characteristics, PAD alone was associated with significantly higher mortality and complications postoperatively (OR 1.71; P < 0.001, and 1.28; P < 0.001, respectively), but concurrent DM + PAD was not associated with these outcomes. CONCLUSION: Outcomes were significantly affected by presence of PAD as a comorbidity in patients undergoing LEA. It is imperative to understand and enhance preventive measures and screening guidelines for such comorbidities to optimize postoperative outcomes to ensure best-practice care in this patient population.

Assessment of Risk Factors for Iatrogenic Genitourinary Injuries During a Proctectomy.

BACKGROUND: It is critical to avoid iatrogenic injuries affecting genitourinary organs in order to prevent postoperative urinary or sexual dysfunction, which lead to lengthier recovery and possibly reoperation. METHODS: Using the 2016-2019 American College of Surgeons National Quality Improvement Program (ACS NSQIP) Targeted Proctectomy Database, we collated 2577 patients with non-metastatic rectal cancer who underwent a laparoscopic or open proctectomy. Univariate analysis was used to identify differences in perioperative factors and genitourinary injuries (GUIs) between operative approaches, and multivariate logistic regression was used to identify independent risk factors for sustaining an intraoperative GUI. RESULTS: The rates of preoperative comorbidities were significantly higher among patients who received an open operation. The proportion of GUIs was also significantly higher in this patient population. Multivariate logistic regression demonstrated that patients who underwent a laparoscopic proctectomy were associated with a 51.4% lower risk of sustaining a GUI. Furthermore, >10% body weight loss in the past 6 months and ASA class 3 status were independently associated with a higher risk of GUI regardless of operation type. CONCLUSION: Patients who undergo a laparoscopic proctectomy are associated with a lower risk of GUI. On the other hand, patients with >10% body weight loss and ASA class 3: Severe Systemic Disease were associated with a higher risk of GUI.

Kinetics and genomic profiling of adult human and mouse ß-cell maturation.

Diabetes is a multifactorial metabolic disorder defined by the loss of functional pancreatic insulin-producing ß-cells. The functional maturation and dedifferentiation of adult ß-cells is central to diabetes pathogenesis and to ß-cell replacement therapy for the treatment of diabetes. Despite its importance, the dynamics and mechanisms of adult ß-cell maturation remain poorly understood. Using a novel Pdx1/Ins1 dual fluorescent reporter lentiviral vector, we previously found that individual adult human and mouse ß-cells exist in at least two differentiation states distinguishable by the activation of the rat Ins1 promoter and performed the first real-time imaging of the maturation of individual cultured ß-cells. Our previous study focused on transformed (MIN6) ß-cells as a model to investigatethe kinetics of ß-cell maturation. In the present study, we investigated the kinetics of the maturation process in primary human and mouse ß-cells and performed gene expression profiling. Gene expression profiling of FACS purified immature Pdx1 (+) /Ins1 (low) cells and mature Pdx1 (high) /Ins1 (high ) cells from cultures of human islets, mouse islets and MIN6 cells revealed that Pdx1 (+) /Ins1 (low) cells are enriched for multiple genes associated with ß-cell development/progenitor cells, proliferation, apoptosis, as well as genes coding for other islet cell hormones such as glucagon. We also demonstrated that the heterogeneity in ß-cell maturation states previously observed in vitro, can also be found in vivo. Collectively, these experiments contribute to the understanding of maturation, dedifferentiation and plasticity of adult pancreatic ß-cells. The results have significant implications for islet regeneration and for in vitro generation of functional ß-cells to treat diabetes.