Extrapolative Validity Evidence of the Anastomosis Objective Structured Assessment of Technical Skill (A-OSATS) for Robotic Ileocolic Anastomosis.

OBJECTIVE: To collect validity evidence for the use of the Anastomosis Objective Structured Assessment of Technical Skills (A-OSATS) instrument, which has been developed to evaluate performance of a minimally invasive side-to-side bowel anastomosis with hand-sewn common enterotomy. DESIGN: Residents performed a robotic ileocolic anastomosis simulation on an ex vivo porcine model. Faculty scored each resident with the A-OSATS and performed a provocative leak test on the completed anastomoses. Residents were reassessed on the sewing sub-score 1 month later. Data were compared with parametric and nonparametric analysis. SETTING: Single academic general surgery residency PARTICIPANTS: PGY-4 and -5 general surgery residents (n = 17) RESULTS: PGY-5s performed better than PGY-4s in repeat A-OSATS sewing sub-score (mean 55/55 ± 0 vs 43 ± 4.9, p < 0.001) and time to complete (minutes, mean 14.5 ± 4.9 vs 21.2 ± 3.9, p = 0.01). There was a strong correlation between A-OSATS score and time (r = -0.67, p = 0.005). For the initial assessment, there was no significant difference in mean A-OSATS score between anastomoses that leaked and those that did not leak (137.3 ± 14.5 vs 150.1 ± 11.2, p = 0.098), but on repeat assessment, intact anastomoses had a higher mean A-OSATS sewing sub-score than those that leaked (52.2 ± 4.7 vs 39 ± 3.5, p = 0.007). There was no significant difference between initial A-OSATS score and repeat score (p = 0.14). CONCLUSIONS: We provide extrapolative validity evidence for the A-OSATS instrument by comparing A-OSATS score to time to sew, provocative leak test, and discrimination between PGY-4s and PGY-5s. Generalizability validity evidence is provided by test-retest reliability. Further refinement is needed for the A-OSATS tool to be used for high-stakes entrustment decisions in resident-performed robotic ileocolic anastomoses.

Use of Simulation For Training Advanced Colorectal Procedures.

OBJECTIVE: Simulation training for minimally invasive colorectal procedures is in developing stages. This study aims to assess the impact of simulation on procedural knowledge and simulated performance in laparoscopic low anterior resection (LLAR) and robotic right colectomy (RRC). DESIGN: LLAR and RRC simulation procedures were designed using human cadaveric models. Resident case experience and simulation selfassessments scores for operative ability and knowledge were collected before and after the simulation. Colorectal faculty assessed resident simulation performance using validated assessment scales (OSATS-GRS, GEARS). Paired t-tests, unpaired t-tests, Pearson's correlation, and descriptive statistics were applied in analyses. SETTING: Barnes-Jewish Hospital/Washington University School of Medicine in St. Louis, Missouri. PARTICIPANTS: Senior general surgery residents at large academic surgery program. RESULTS: Fifteen PGY4/PGY5 general surgery residents participated in each simulation. Mean LLAR knowledge score increased overall from 10.0 ±  2.0 to 11.5  ±  1.6 of 15 points (p = 0.0018); when stratified, this increase remained significant for the PGY4 cohort only. Mean confidence in ability to complete LLAR increased overall from 2.0 ±  0.8 to 2.8  ± 0.9 on a 5-point rating scale (p = 0.0013); when stratified, this increase remained significant for the PGY4 cohort only. Mean total OSATS GRS score was 28  ±  6.3 of 35 and had strong positive correlation with previous laparoscopic colorectal experience (r = 0.64, p = 0.0092). Mean RRC knowledge score increased from 9.4 ±  2.2 to 11.1 ±  1.5 of 15 points (p = 0.0030); when stratified, this increase again remained significant for the PGY4 cohort only. Mean confidence in ability to complete RRC increased from 1.9 ±  0.9 to 3.2  ±  1.1 (p = 0.0002) and was significant for both cohorts. CONCLUSIONS: Surgical trainees require opportunities to practice advanced minimally invasive colorectal procedures. Our simulation approach promotes increased procedural knowledge and resident confidence and offers a safe complement to live operative experience for trainee development. In the future, simulations will target trainees on the earlier part of the learning curve and be paired with live operative assessments to characterize longitudinal skill progression.

A Percutaneous Endoscopic Colostomy Tube to the Rescue.

Percutaneous endoscopic colostomy (PEC) tube placement is a minimally invasive procedure used to treat recurrent colonic pseudo-obstruction, sigmoid volvulus, chronic intractable constipation, and neurogenic bowel. PEC is a viable treatment alternative for patients who have failed conservative therapies and are deemed high risk for surgical management. We present a case of acute colonic pseudo-obstruction after Clostridioides difficile infection that was unresponsive to medical treatment or endoscopic decompression. A PEC tube was placed into the transverse colon with successful resolution of the colonic distension.

Treating acute diverticulitis in pre- and post-solid-organ transplant patients: a single-institution cohort study.

AIM: Immunosuppressed patients are more likely to fail nonoperative management of acute diverticulitis and have more postoperative complications than the immunocompetent. Transplant recipients form a subcategory among the immunosuppressed with unique challenges. The aim of this work is to report 30-day postoperative complications after colectomy for acute diverticulitis and success rates of nonoperative management in pre- and post-transplant patients. METHOD: This is a retrospective cohort study at a single-institution tertiary referral centre. Patients with a history of acute diverticulitis were extracted from a database of 6152 recipients of solid-organ abdominal transplant between 2000 and 2015 and stratified by the index episode of diverticulitis: before or after solid-organ transplant surgery. Outcomes included 30-day postoperative complications and failure of nonoperative management. RESULTS: Acute diverticulitis occurred in 93 patients, 69 (74%) posttransplant. Postcolectomy complications were higher posttransplant than pretransplant (43% vs. 13%, p = 0.04). Posttransplant status was not an independent risk factor for complications (odds ratio 3.59, 95% CI 0.79-16.31) when adjusting for sex and surgical acuity. Immediate urgent colectomy (29% vs. 31%, p = 0.84) and failure of nonoperative management (7% vs. 9%, p = 0.82) were similar. Complications occurred equally in those requiring urgent colectomy after nonoperative management and those undergoing immediate urgent colectomy. CONCLUSION: Urgent colectomy rates are similar in solid-organ abdominal transplant recipients pre- and posttransplant. Posttransplant complication rates appear to be increased but transplant status as an independent factor is not significantly associated with an increased risk in this study cohort. These findings should be considered when counselling patients on the relative risks and benefits of surgical intervention for diverticulitis before versus after solid-organ transplantation.

Impaired outcome colitis-associated rectal cancer versus sporadic cancer.

BACKGROUND: The surgical management of colitis-associated rectal cancer (CARC) is not well defined. This study determines outcomes after surgery for CARC compared with sporadic rectal cancer. MATERIALS AND METHODS: This is a retrospective cohort study comparing 27 patients with CARC with 54 matched patients with sporadic cancer. Matching criteria included age, gender, neoadjuvant chemoradiation, and American Joint Committee on Cancer stage. Outcome measures were disease-free and overall survival, tumor characteristics, and postoperative morbidity. RESULTS: Compared to those with sporadic rectal cancer, patients with CARC underwent proctocolectomy more frequently (21 [78%] versus 6 [22%] P < 0.001) and were more likely to have mucinous tumors (11 [40.7%] versus 12 [22.3%] P = 0.03). Overall 3-y survival was significantly reduced in CARC patients compared with patients with sporadic rectal cancer. Those with CARC undergoing segmental proctectomy only demonstrated reduced overall and disease-free survival compared to patients with sporadic rectal cancer and to colitis patients undergoing proctocolectomy (P = 0.002). CONCLUSIONS: Patients with CARC undergoing proctectomy demonstrate reduced disease-free survival versus those undergoing proctocolectomy, and versus patients with sporadic rectal cancer undergoing proctectomy. These findings warrant further study and suggest that proctocolectomy should be considered the preferred surgical approach for CARC.

The prognostic value of lymph node ratio in colon cancer is independent of resection length.

BACKGROUND: Lymph node ratio (LNR), the ratio of tumor-positive lymph nodes (+LN) to the total number of resected lymph nodes (rLN), predicts recurrence and survival in colon cancer. Variations in colonic resection length (RL) may influence rLN, +LN, or both, thereby potentially impacting LNR and its prognostic value in colon cancer. METHODS: All colon cancer patients treated surgically at our center from 2004 to 2011 were included in an institutional review board-approved data repository (n = 1,039). RESULTS: Larger RL was associated with increased rLN (ρ = .22; P < .001) but not with +LN (P = .21). In node-positive patients (n = 411), RL-adjusted LNR had weaker correlations with death (ρ = .338 vs .373, both P < .001) or metastatic disease (ρ = .303 vs .345; both P < .001) and a smaller area under the curve (death: .695 vs .715, metastasis: .675 vs .699). Findings were similar in segmental, extended segmental, and total colectomy subgroups. CONCLUSIONS: Provided that resections are performed following standard oncologic principles, our analysis shows that RL does not significantly impact the prognostic value of LNR in colon cancer. Correcting LNR for RL seems redundant and may even act as noise distorting LNR values.

Polyp Genetics.

The genetic events involved in the transformation of normal colonic epithelium to neoplastic polyps to invasive carcinoma, as initially proposed by Fearon and Vogelstein, form the foundation of our understanding of colorectal cancer. The identification of the polyp as the precursor lesion to colorectal cancer is the basis of many of our current practices for screening, surveillance, and prevention. The last three decades have seen a veritable explosion in our understanding of the molecular events involved in the pathogenesis of colorectal cancer. It is now clear that there are multiple genetic pathways in the polyp to carcinoma sequence. Some polyps previously thought to be nonneoplastic have now been shown to have malignant potential. Finally, increased understanding of the sequence of genetic events has led to the development of targeted therapeutics. The clinical translation of these scientific advances has made a significant impact on the management of patients with colorectal cancer. Accordingly, it is imperative that all clinicians caring for these patients have an understanding of the genetics of colorectal polyps and cancer. In this article, we review the etiology and genetic pathways to carcinoma associated with a range of polyps of the colon and rectum.

Intestinal epithelial HuR modulates distinct pathways of proliferation and apoptosis and attenuates small intestinal and colonic tumor development.

HuR is a ubiquitous nucleocytoplasmic RNA-binding protein that exerts pleiotropic effects on cell growth and tumorigenesis. In this study, we explored the impact of conditional, tissue-specific genetic deletion of HuR on intestinal growth and tumorigenesis in mice. Mice lacking intestinal expression of HuR (Hur (IKO) mice) displayed reduced levels of cell proliferation in the small intestine and increased sensitivity to doxorubicin-induced acute intestinal injury, as evidenced by decreased villus height and a compensatory shift in proliferating cells. In the context of Apc(min/+) mice, a transgenic model of intestinal tumorigenesis, intestinal deletion of the HuR gene caused a three-fold decrease in tumor burden characterized by reduced proliferation, increased apoptosis, and decreased expression of transcripts encoding antiapoptotic HuR target RNAs. Similarly, Hur(IKO) mice subjected to an inflammatory colon carcinogenesis protocol [azoxymethane and dextran sodium sulfate (AOM-DSS) administration] exhibited a two-fold decrease in tumor burden. Hur(IKO) mice showed no change in ileal Asbt expression, fecal bile acid excretion, or enterohepatic pool size that might explain the phenotype. Moreover, none of the HuR targets identified in Apc(min/+)Hur(IKO) were altered in AOM-DSS-treated Hur(IKO) mice, the latter of which exhibited increased apoptosis of colonic epithelial cells, where elevation of a unique set of HuR-targeted proapoptotic factors was documented. Taken together, our results promote the concept of epithelial HuR as a contextual modifier of proapoptotic gene expression in intestinal cancers, acting independently of bile acid metabolism to promote cancer. In the small intestine, epithelial HuR promotes expression of prosurvival transcripts that support Wnt-dependent tumorigenesis, whereas in the large intestine epithelial HuR indirectly downregulates certain proapoptotic RNAs to attenuate colitis-associated cancer. Cancer Res; 74(18); 5322-35. ©2014 AACR.

Segmental versus extended resection for sporadic colorectal cancer in young patients.

BACKGROUND AND OBJECTIVES: Guidelines on the management of colon cancer state that extensive colectomy should be "considered" for patients of young age (<50). This study aimed to compare the risk of metachronous cancer, overall recurrence and mortality between segmental and extended colon resections in patients under the age of 50 with sporadic CRC. METHODS: We performed a retrospective review of patients age <50 undergoing surgery for CRC from 1991 to 2009. Patients were divided into two groups based on extent of resection: segmental versus extended. The primary outcomes analyzed were metachronous tumors, disease recurrence, and overall survival. RESULTS: Two hundred seventy one patients underwent segmental resection and 30 underwent extended resection. 3.3% in the segmental resection group developed metachronous CRC versus 0% in the extended resection group (P = 0.61). There was no significant difference in the risk of recurrence or mortality for those who underwent a segmental resection compared to those with an extended resection. In a regression model, type of surgery was not an independent risk factor for recurrence or mortality. CONCLUSIONS: Extended colectomy for sporadic CRC in patients younger than 50 does not improve disease-free or overall survival. Further study to determine if segmental resection is appropriate oncologic treatment is warranted.

Accordion complication grading predicts short-term outcome after right colectomy.

BACKGROUND: The Accordion severity grading system is a novel system to score the severity of postoperative complications in a standardized fashion. This study aims to demonstrate the validity of the Accordion system in colorectal surgery by correlating severity grades with short-term outcomes after right colectomy for colon cancer. METHODS: This is a retrospective cohort review of patients who underwent right colectomy for cancer between January 1, 2002, and January 31, 2007, at a single tertiary care referral center. Complications were categorized according to the Accordion severity grading system: grades 1 (mild), 2 (moderate), 3-5 (severe), and 6 (death). Outcome measures were hospital stay, 30-d readmission rate and 1-y survival. Correlation between Accordion grades and outcome measures is reflected by Spearman rho (ρ). One-year survival was obtained per Kaplan-Meier method and compared by logrank test for trend. Significance was set at P ≤ 0.05. RESULTS: Overall, 235 patients underwent right colectomy for cancer of which 122 (51.9%) had complications. In total, 52 (43%) had an Accordion grade 1 complication; 44 (36%) grade 2; four (3%) grade 3; 11 (9%) grade 4; seven (6%) grade 5; and four (3%) grade 6. There was significant correlation between Accordion grades and hospital stay (ρ = 0.495, P < 0.001) and 30-d readmission rate (ρ = 0.335, P < 0.001). There was a significant downward trend in 1-y survival as complication severity by Accordion grade increased (P = 0.02). CONCLUSIONS: The Accordion grading system is a useful tool to estimate short-term outcomes after right colectomy for cancer. High-grade Accordion complications are associated with longer hospital stay and increased risk of readmission and mortality.