Larson, David W.

INTRODUCTION: An IPAA is the preferred operative approach for restoration of intestinal continuity in patients with ulcerative colitis and familial adenomatous polyposis. As minimally invasive approaches have become more widely adopted, their use in IPAA has also become increasingly commonplace. Laparoscopy has the same limitations during the proctectomy portion as seen in operations for rectal cancer, including dissection in the mid-to-lower rectum attributed to angles created by bony confines of the deep pelvis and lack of visibility when constructing the anastomosis. Robotic surgery provides improved 3-dimensional and high-definition visualization of the pelvis and multiple degrees of freedom, which greatly enhance performance during the proctectomy and construction of the anastomosis. TECHNIQUE: In the setting of a previous subtotal colectomy, the ileostomy site is taken down and stapled across. A 15-mm balloon trocar is placed in the site to achieve insufflation, and the robotic ports are placed horizontally just above the umbilicus. The lateral mesenteric attachments are mobilized laparoscopically, then the J-pouch is constructed through the ostomy site. The J-pouch is placed back into the abdomen with the anvil in place, and the proctectomy is performed after docking the robot. The rectum is stapled with the robotic stapler and exteriorized from the ileostomy site, and the anastomosis is constructed under direct robotic visualization. RESULTS: In addition to the potential ergonomic advantages, the maneuverability and visualization in the pelvis during the proctectomy and construction of the anastomosis are reported by many surgeons to be improved as compared with laparoscopy, especially in male or obese patients. CONCLUSIONS: A robotic approach during the proctectomy and IPAA offers significant advantages to a laparoscopic approach, expanding our armamentarium of minimally invasive surgical techniques to IPAA.

Abstract Background Deficiencies in the DNA mismatch repair system cause errors during DNA replication, which in turn give rise to microsatellite instability (MSI). The impact of MSI on survival in metastatic colorectal cancer (mCRC) is unclear. This cohort study aims to investigate the prognostic and predictive value of MSI in mCRC prior to the immune therapy era. Materials and Methods A total of 75 MSI-high (MSI-H) mCRC patients (pts) and 75 matched (age, gender, disease sidedness, metachronous/synchronous) microsatellite-stable (MSS) mCRC pts were identified from 1,268 mCRC pts who had MSI/mismatch repair test results at Mayo Clinic Rochester between January 1992 and July 2016. A retrospective review was conducted by using data from electronic medical records. Statistical analyses utilized the Kaplan-Meier method, log-rank test, and Cox proportional hazards models. Results The MSS group was well matched to the MSI-H group based on age, gender, location, and chronicity of metastatic disease. MSI-H mCRC pts had earlier disease recurrence (median time from initial diagnosis to metastatic disease diagnosis, MSI-H group 12.9 vs. MSS group 20.9 months, p = .034). Median overall survival (OS) was 28.1 and 37.4 months for MSI-H and MSS pts, respectively (p = .99). In total, 94.7% of MSI-H pts and 98.7% of MSS pts had fluoropyrimidine-based chemotherapy for metastatic disease, and there was no difference in OS between these two groups (32.3 vs. 37.4 months, p = .91). Forty-three MSI-H and thirty-nine MSS pts had metastasectomy and/or ablation of metastases (p = .51) with longer median OS compared with pts without metastasectomy (MSI-H: 82.0 vs. 13.9, p < .001; MSS: 69.9 vs. 19.7, p < .001). Age <65 years, BRAF wild type, and metastasectomy were associated with better OS in univariate analysis. Only metastasectomy remained statistically significant in multivariate analysis (p < .001). Conclusion In mCRC, patients with MSI-H tumors have similar, but numerically shorter, median overall survival compared with those with MSS tumors. In both groups, metastasectomy and ablation of metastatic disease should be considered to optimize OS. Implications for Practice This study clearly demonstrated the survival benefits that aggressive metastasectomy provides in selected microsatellite instability-high metastatic colorectal cancer patients. This could be meaningful practice-changing information that has been long awaited.

Abstract Background The prognostic value of pathological lymph node status following neoadjuvant radiotherapy (ypN) remains unclear. This study was designed to determine whether ypN status predicted overall survival. Methods Patients with locally advanced rectal adenocarcinoma who underwent neoadjuvant long-course radiation between 2005 and 2014 were identified from the National Cancer Data Base, and divided into ypN0, ypN1 and ypN2 groups. The primary outcome was overall survival. Univariable and multivariable analyses were used to determine factors associated with overall survival. Results Of 12 271 patients, 3713 (30·3 per cent) were found to have residual nodal positivity. A majority of patients with ypN1 (1663 of 2562) and ypN2 (878 of 1151) disease had suspected lymph node-positive disease before neoadjuvant therapy, compared with 3959 of 8558 with ypN0 tumours (P < 0·001). Moreover, ypN1 and ypN2 were significantly associated with ypT3–4 disease (65·7 and 83·0 per cent respectively versus 39·4 per cent for ypN0; P < 0·001). In unadjusted analyses, survival differed significantly between ypN groups (P < 0·001). Five-year survival rates were 81·6, 71·3 and 55·0 per cent for patients with ypN0, ypN1 and ypN2 disease respectively. After adjustment for confounding variables, ypN1 and ypN2 remained independently associated with overall survival: hazard ratio (HR) 1·61 (95 per cent c.i. 1·46 to 1·77) and 2·63 (2·34 to 2·95) respectively (P < 0·001). Overall survival was significantly longer in patients with ypN1–2 combined with ypT0–2 status than among those with ypT3–4 tumours even with ypN0 status (P = 0·031). Clinical nodal status before neoadjuvant therapy was not significantly associated with overall survival (HR 1·05, 0·97 to 1·13; P = 0·259). Conclusion Both ypT and ypN status is of prognostic significance following neoadjuvant therapy for rectal cancer.

Purpose. Multimodal analgesia is an essential component of an enhanced recovery pathway (ERP). An ERP that includes the use of single-injection intrathecal analgesia (IA) has been shown to decrease morbidity and cost and shorten length of stay (LOS). Limited data exist on safety, feasibility, and the optimal IA regimen. Our objective was to characterize the efficacy, safety, and feasibility of IA within an ERP in a cohort of colorectal surgical patients. Methods. We performed a retrospective review of all consecutive patients aged ≥ 18 years who underwent open or minimally invasive colorectal surgery from October 2012 to December 2013. All patients were enrolled in an institutional ERP that included the use of single-injection IA. Demographics, anesthetic management, efficacy (pain scores and opiate consumption), postoperative ileus (POI), adverse effects, and LOS are reported. Results. 601 patients were identified. The majority received opioid-only IA (91%) rather than a multimodal regimen. Median LOS was 3 days. Overall rate of ileus was 16%. Median pain scores at 4, 8, 16, 24, and 48 hours were 3, 2, 3, 4, and 3, respectively. There was no difference in postoperative pain scores, LOS, or POI based on intrathecal medication or dose received. Overall, development of respiratory depression (0.2%) or pruritus (1.2%) was rare. One patient required blood patch for postdural headache. Conclusion. Intrathecal analgesia is safe, feasible, and efficacious in the setting of ERP for colorectal surgery. All regimens and doses achieved a short LOS, low pain scores, and a low incidence of POI. This trial is registered with Clinicaltrails.gov NCT03411109.

Abstract Background The purpose of this study was to define survival rates in patients with isolated advanced abdominal nodal metastases secondary to colorectal cancer (CRC), treated with curative-intent trimodality therapy. Materials and Methods Sixty-five patients received trimodality therapy, defined as chemotherapy delivered with external beam radiotherapy (EBRT) followed by lymphadenectomy and intraoperative radiotherapy (IORT). Infusional 5-fluorouracil was the most common radiosensitizer used (63%, 41 patients). The median dose of EBRT was 50 Gy, and the median dose of IORT was 12.5 Gy. We evaluated time to distant metastasis, toxicities, local failure within the EBRT field, recurrence within the IORT field, and survival. Results Fifty-two percent of patients were male; patients’ median age was 50.5 years. All patients had an Eastern Cooperative Oncology Group score ≤1. Twenty-nine patients had right-sided colon cancer, 22 had left-sided colon cancer, and 14 had rectal primaries. The median time from initial CRC diagnosis to development of abdominal nodal metastatic disease was 20.6 months (95% confidence interval [CI], 21.2–40.8 months). Seventy-eight percent (51 patients) had para-aortic nodal metastases, 15% (10 patients) had mesenteric nodal metastases, and 6% (4 patients) had both. With a median follow-up of 77.6 months, the median overall survival and 5-year estimated survival rate were 55.4 months (95% CI, 47.2–80.9 months) and 45%, respectively. The median progression-free survival was 19.3 months (95% CI, 16.5–32.8 months). Twenty-six (40%) patients never developed distant disease. The outcome was not affected by disease sidedness or rectal primary. Treatment was well tolerated without grade 3 or 4 toxicities. Conclusion Trimodality therapy produces sustainable long-term survival in selected patients with metastatic CRC presenting with isolated retroperitoneal or mesenteric nodal relapse. Implications for Practice This article reports a unique trimodality approach incorporating external beam radiotherapy with radiosensitizing chemotherapy, surgical resection, and intraoperative radiotherapy provides durable survival benefit with significant curative potential for patients with metastatic colorectal cancer who present with isolated abdominal nodal (mesenteric and/or retroperitoneal) recurrence.

Background Meckel's diverticulum is present in about 2% of the population. The literature reports 3.2% incidence of tumors within Meckel's diverticulum; the tumors are predominantly benign. Objective and methods The purpose of this study was to evaluate malignant tumors in Meckel's diverticulum through systematic review of the literature and review of electronic medical records including pathology reports over 14 years at the Mayo Clinic, Rochester, USA. Results A literature review over the last 10 years identified 37 citations with 402 patients (median age: 58 years; 68.9% males). The predominant malignancy reported was neuroendocrine tumor 84.6%, followed by gastrointestinal stromal tumor 8.2%, and adenocarcinoma 6%. At the time of diagnosis, 29.5% of patients had metastases. In the Mayo Clinic electronic medical records review, there were 19 patients (5.1% of them surgically removed Meckel's diverticulum) who had a malignancy associated with Meckel's diverticulum: 63.2% neuroendocrine tumor, 10.5% gastrointestinal stromal tumor, 5.3% adenocarcinoma, 5.3% pancreatic epithelial neoplasia, and 15.8% metastases from secondary location. Median size of the malignancy was 7 mm, and 17/19 malignancies were coincidental findings. Most neuroendocrine tumors infiltrated the submucosa, while gastrointestinal stromal tumor and adenocarcinoma invaded the serosa. At the time of diagnosis, 33.3% of patients had metastases. Conclusion About 5% of Meckel's diverticulums resected were associated with malignant tumors, most commonly neuroendocrine tumor, and a significant portion of Meckel's diverticulum malignancy was metastatic at the time of discovery.

BACKGROUND: Despite distant historical studies that demonstrated the adequacy of preoperative antibiotic prophylaxis, current surgical practice continues to use antibiotics for postoperative coverage up to 24 hours. OBJECTIVE: The aim of this study was to evaluate a change in antibiotic prophylaxis duration and its effect on surgical site infection in a high-volume modern colorectal practice. DESIGN: A case-controlled series retrospectively reviewed outcomes through a prospective validated data base. SETTING: The study was conducted at Mayo Clinic, Rochester, Minnesota. PATIENTS: A total of 965 patients were evaluated. Our study analyzed patient outcomes related to surgical site infection comparing cohort 1 (2012–2013), which had the same antibiotic coverage preoperatively up to 24 hours postoperatively, and cohort 2 (2014–2015), which eliminated postoperative doses and relied solely on pre- and intraoperative dosing duration. MAIN OUTCOME MEASURES: The primary outcomes of this study are superficial and deep surgical site infection. RESULTS: There were no differences identified for superficial or deep surgical site infection rates between cohorts. Before the change in antibiotic dosing duration (2012–2013), 28 of 493 patients (5.7%) vs after the practice change (2014–2015), 25 of 472 patients (5.3%) were reported to have superficial or deep surgical site infection (p = 0.794). LIMITATIONS: This study is limited by its retrospective design within a single institution. CONCLUSION: These equivalent results present an opportunity for surgeons to reconsider optimal antibiotic duration and minimize unnecessary antibiotic dosing. See Video Abstract at http://links.lww.com/DCR/A322.

Hospital-specific electronic health record systems are used to inform clinical practice about best practices and quality improvements. Many surgical centers have developed deterministic clinical decision rules to discover adverse events (e.g. postoperative complications) using electronic health record data. However, these data provide opportunities to use probabilistic methods for early prediction of adverse health events, which may be more informative than deterministic algorithms. Electronic health record data from a set of 9598 colorectal surgery cases from 2010 to 2014 were used to predict the occurrence of selected complications including surgical site infection, ileus, and bleeding. Consistent with previous studies, we find a high rate of missing values for both covariates and complication information (4–90%). Several machine learning classification methods are trained on an 80% random sample of cases and tested on a remaining holdout set. Predictive performance varies by complication, although an area under the receiver operating characteristic curve as high as 0.86 on testing data was achieved for bleeding complications, and accuracy for all complications compares favorably to existing clinical decision rules. Our results confirm that electronic health records provide opportunities for improved risk prediction of surgical complications; however, consideration of data quality and consistency standards is an important step in predictive modeling with such data.

535 Background: The most effective management of locally recurrent colorectal cancer (CRC) is resection. This is also true for hepatic metastases (HM). Data remains limited, however, regarding concomitant resection of recurrent CRC and HM. The aims of this study were to determine the feasibility, safety and outcomes in terms of disease-free survival (DFS) and overall survival (OS) in patients undergoing concomitant resection of recurrent CRC with HM. Methods: All patients who underwent resection of recurrent CRC from 1/1995 to 1/2007 at Mayo Clinic, Rochester were reviewed (n=406). The study group consisted of patients who underwentconcomitant resection of locally recurrent CRC and hepatic resection for metastatic CRC (n= 45). Kaplan-Meier Survival was used to estimate DFS and OS. Results: The study group consisted of 27 men and 18 women. The median age was 59 years. Surgical management involved pelvic dissection in 43 patients and ileotransverse colectomy in two. 17 patients required resection of contiguous organs. 24 patients received intra-operative radiation. 34 patients underwent multiple hepatic wedge resections, 6 patients segmentectomy, 3 left hepatectomy, and 2 right hepatectomy. There was no perioperative mortality. Morbidity was 37%, 2 patients required re-operation. The 1, 3, and 5 year DFS was 72.2, 42.3, and 18.5%, respectively. The 1, 3, and 5 year OS was 87.7, 47.6, and 36.2%, respectively. Conclusions: Synchronous resection of locally recurrent CRC and HM is safe and feasible; morbidity is reasonable and mortality zero. DFS and OS in this patient population appear comparable to that of patients undergoing separate, staged resections.

711 Background: For patients with stage IVA rectal cancer with liver metastases treated with curative-intent chemotherapy and surgery, the role of adjuvant pelvic radiotherapy (RT) is unclear. The purpose of this study was to evaluate the impact of pelvic RT on oncologic outcomes in this patient population. Methods: We retrospectively reviewed medical records of all patients with stage IVA rectal adenocarcinoma with liver metastases treated with curative-intent resection of the primary tumor and all liver metastases at our institution between 1991 and 2010. Patient and treatment characteristics were compared between patients who did or did not receive pelvic RT using chi-square and unpaired ttests. Survival and recurrence estimates were calculated from date of initial diagnosis using the Kaplan-Meier method. Local recurrence (LR) was defined as recurrence in the pelvis occurring at or before distant recurrence (DR). Cox regression was used to compare rates of freedom from LR (FFLR), freedom from DR (FFDR), and overall survival (OS) between patients who did or did not receive pelvic RT. Results: The analysis included 65 patients. Median patient age at diagnosis was 59 years (range, 27-87). Tumor stage was T2 (n = 4), T3 (n = 53), or T4 (n = 8). The median number of liver metastases was 2 (range, 1-14). Surgery was low anterior resection (n = 54) or abdominoperineal resection (n = 11). All patients received perioperative fluoropyrimidine based chemotherapy. Pelvic RT was administered to 35 patients (54%), either preoperatively (n = 22) or postoperatively (n = 13). Median RT dose was 50.4 Gy (range 25-58). Patient characteristics were similar for those who did or did not receive pelvic RT. Median follow-up was 3.7 years. The 3-year estimates of FFLR, FFDR and OS were 81% vs 58% (p =.056), 35% vs 29% (p =.75), and 66% vs 71% (p =.81) for RT vs no RT, respectively. Conclusions: In this analysis of patients with stage IVA rectal cancer with liver metastases undergoing curative intent therapy, pelvic RT (vs. no pelvic RT) was associated with a trend to lower rates of LR and similar rates of DR and OS.