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Nicholas G Berger, Timothy J Ridolfi, Kirk A LudwigDivision of Colorectal Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin USAAbstract: Postoperative Ileus (POI), which occurs after surgical manipulation of the bowel during abdominal operations, is associated with prolonged hospital stay, increasing medical costs, and delayed advancement of enteral diet, which contributes to a significant economic burden on the healthcare system. The use of accelerated care pathways has shown to positively impact gut function, but inevitable postoperative opioid use contributes to POI. Alvimopan is a peripherally acting µ-opioid receptor antagonist designed to mitigate antimotility effects of opioids. In our review, we examined ten trials on alvimopan's use after abdominal operations. Several of the earlier studies on patients undergoing bowel resection showed correlations between the study group and GI recovery as defined by passage of flatus, first bowel movement, and time to readiness for discharge. Data in patients undergoing total abdominal hysterectomy showed similarly decreased GI recovery time. Additionally, data within the past few years shows alvimopan is associated with more rapid GI recovery time in patients undergoing radical cystectomy. Based on our review, use of alvimopan remains a safe and potentially cost-effective means of reducing POI in patients following open GI surgery, radical cystectomy, and total abdominal hysterectomy, and should be employed following these abdominal operations.Keywords: postoperative ileus, alvimopan, ileus, bowel resection, return of bowel function

Introduction: Mounting evidence supports traveling to high-volume centers for complex surgical procedures, such as a proctectomy, yet the burden of travel and outcomes of patients traveling long distances is not yet clear. Thus, we aimed to evaluate oncologic outcomes, quality of life, and travel burdens for patients treated for rectal cancer at a single tertiary-care institution., Methods: A retrospective study of patients treated with proctectomy for locally advanced rectal cancer was performed comparing long and short travel distance (STD) cohorts. Primary outcome measures included overall mortality, disease recurrence, and quality of life. Secondary outcomes included out-of-pocket expenses. The cohorts were compared using Wilcoxon rank-sum and Chi-square tests for continuous and categorical variables, respectively. Kaplan-Meier plots were created to evaluate overall and disease-free survival., Results: Among 102 patients, 51 (50%) were classified as long travel distance (LTD, mean 57.8 miles) and 51 (50%) were classified as STD (mean 12.8 miles). There was no statistical difference in 5-y mortality (4% LTD versus 4% STD, P = 1.000), disease recurrence (26% LTD versus 18% STD, P = 0.336), or quality of life (0.85 LTD versus 0.87 STD, P = 0.690). The LTD cohort did have significantly lower postresection compliance with surveillance (84% LTD versus 96% STD, P = 0.046). LTD cohort also had significantly more lodging ($77.1 LTD versus $0 STD, P = 0.025) and transportation expenses ($133.6 LTD versus $92.6 STD, P = 0.010)., Conclusions: As the surgical management of rectal cancer becomes increasingly centralized, this study found patients who traveled long-distances received comparable care with outcomes similar to those who lived locally. Higher travel costs and lower compliance with surveillance were identified as barriers to care in the long-distance population, but a number of solutions can be implemented to address these issues., (Copyright © 2024. Published by Elsevier Inc.)

Background: While self-sampling could help address anal cancer screening barriers, no studies have investigated annual engagement with this method or compared it to annual screening with a provider. Building on our baseline paper,(7) we compared annual anal screening engagement between home-based self-sampling and clinic-based clinician sampling., Methods: The Prevent Anal Cancer Self-Swab Study recruited and randomized sexual and gender minority individuals 25 years and over who have sex with men to a home or clinic arm. Home-based participants were mailed an anal human papillomavirus self-sampling kit at baseline and 12 months, while clinic-based participants were asked to schedule and attend one of five participating clinics at baseline and 12 months. Using Poisson regression, we conducted an intention-to-treat analysis of 240 randomized participants who were invited to screen at both timepoints., Results: 58.8% of participants completed annual (median = 370 days) anal screening. In the home arm, 65.0% of participants engaged in annual screening compared to 52.5% of clinic-based participants (p = 0.049). When stratified by HIV status, persons living with HIV had a higher proportion of home (71.1%) versus clinic (22.2%) annual screening (p < 0.001). Non-Hispanic Black participants participated more in home-based annual anal screening(73.1%) than annual clinic screening(31.6%) (p = 0.01). Overall, annual screening engagement was significantly higher among participants who had heard of anal cancer from an LGBTQ organization, reported "some" prior anal cancer knowledge, preferred an insertive anal sex position, and reported any prior cancer diagnosis., Conclusions: Annual screening engagement among those at disproportionate anal cancer risk was higher in the home arm., Competing Interests: Conflicts of Interest: The authors declare no conflicts of interest., (Copyright © 2024 American Sexually Transmitted Diseases Association. All rights reserved.)

Background Anal cancer disproportionately affects sexual and gender minority individuals living with HIV. High-resolution anoscopy (HRA) is an in-clinic procedure to detect precancerous anal lesions and cancer, yet prospective data on factors associated with HRA attendance are lacking. We examined whether anal HPV sampling at home versus in a clinic impacts HRA uptake and assessed HRA acceptability. Methods Sexual and gender minority individuals were randomised to home-based self-sampling or clinical sampling. All were asked to attend in-clinic HRA 1year later. We regressed HRA attendance on study arm using multivariable Poisson regression and assessed HRA acceptability using χ 2 tests. Results A total of 62.8% of 196 participants who engaged in screening attended HRA. Although not significant (P =0.13), a higher proportion of participants who engaged in clinic-based screening attended HRA (68.5%) compared to home-based participants (57.9%). Overall, HRA uptake was higher among participants with anal cytology history (aRR 1.40, 95% CI 1.07-1.82), and lower among participants preferring a versatile anal sex position versus insertive (aRR 0.70, 95% CI 0.53-0.91), but did not differ by race or HIV serostatus. In the clinic arm, persons living with HIV had lower HRA attendance (42.9%) versus HIV-negative participants (73.3%) (P =0.02) and Black non-Hispanic participants had lower HRA attendance (41.7%) than White non-Hispanic participants (73.1%), (P =0.04). No differences in attendance by race or HIV status were observed in the home arm. Conclusions HRA uptake differed significantly by race and HIV status in the clinic arm but not the home arm.

Background: Current guidelines recommend elective colectomy for the management of diverticulitis-associated fistulas. These cases present considerable operative challenges, and surgical approaches and fistula tract management vary widely. Hand-assisted laparoscopic surgery offers the benefits of minimally invasive surgery while maintaining the tactile advantages of open surgery. This study aims to evaluate outcomes of hand-assisted laparoscopic surgery colectomy for diverticulitis-associated fistulas, fistula tract, and urinary catheter management., Methods: A retrospective review of patients with diverticulitis-associated fistula who underwent elective hand-assisted laparoscopic surgery colectomy between January 2, 2008, and September 8, 2022, was performed. Patients with Crohn disease or who underwent emergency surgery were excluded., Results: Seventy patients were included; the mean patient age was 64.1 ± 14.8 years, and the mean body mass index was 30.9 ± 9.1 kg/m 2 . Colovesical fistulas were most common (n = 48; 68.6%), followed by colovaginal fistulas (n = 22; 31.4%). The median operative time was 186 minutes. Conversion to an open approach occurred in 4 cases (5.7%). The fistula tract remnant was left without intervention in 35 patients (50%), and omental coverage occurred in 23 cases (32.9%). The median duration of the urinary catheter was 3 days (range = 1-63). There were no postoperative urine leaks. Three patients (4.3%) were readmitted in ≤30 days. There were no 30-day mortalities., Conclusion: The challenges of colectomy for diverticulitis-associated fistulas can be mitigated using the hand-assisted laparoscopic surgery technique. We found a low conversion-to-open rate, falling below rates reported for laparoscopic colectomy. There were no cases of postoperative urine leak, suggesting that no intervention or omental coverage is a safe approach to fistula tract management., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to provide a direct comparison of first-year general surgery resident stipends across states and major cities, using the Cost-of-Living Index (COLI) to determine stipend value., Background: Financial challenges are among residents' top sources of stress, and this may be exacerbated in areas with high costs of living. A 2021 survey found that the mean first-year medical resident stipend increased by 0.6%, or $358, from 2020 to 2021, and only 33% of institutions used cost-of-living to determine annual resident stipend adjustments., Methods: An American Medical Association database was used to identify accredited general surgery residency programs. The 2021-2022 stipend data for first-year general surgery positions were obtained, then data were grouped by state and major city and averaged. Major cities were defined as cities with >4 programs.A direct comparison of stipends was performed using the COLI., Results: Stipend data were available for 337 of 346 general surgery programs. The national average first-year residency stipend was $60,064±$4233. The average COLI-adjusted stipend was $57,090±$5742, with a value loss of -$3493, or 5%.For major cities, the average stipend was $63,383±$4524, and the average COLI-adjusted stipend was $46,929±$8383, with an average value loss of -$16,454, or 26%., Conclusions: The financial burdens that residents face cannot be overlooked, and the cost of living has a meaningful impact on resident stipend value. The current Graduate Medical Education compensation structure limits federal and institutional capacity to adjust for the cost of living and creates an insulated market in which residents are under-compensated., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

The Rothman Index (RI) is a real-time health indicator score that has been used to quantify readmission risk in several fields but has never been studied in gastrointestinal surgery. In this retrospective single-institution study, the association between RI scores and readmissions after unplanned colectomy or proctectomy was evaluated in 427 inpatients. Patient demographics and perioperative measures, including last RI, lowest RI, and increasing/decreasing RI score, were collected. In the selected cohort, 12.4% of patients were readmitted within 30 days of their initial discharge. Last RI, lowest RI, decreasing RI, and increasing RI scores remained significant after controlling for covariates in separate multivariate regression analyses. The last RI score at the time of discharge was found to be the most strongly associated with 30-day readmission risk following colorectal resection. These findings support the RI as a potential tool in the inpatient management of postoperative patients to identify those at high risk of readmission., (Copyright © 2023 the American College of Medical Quality.)

Sexual minority men are at increased risk for anal squamous cell carcinoma. Our objective was to compare screening engagement among individuals randomized to self-collect an anal canal specimen at home or to attend a clinic appointment. Specimen adequacy was then assessed for human papillomavirus (HPV) DNA genotyping. A randomized trial recruited cisgendered sexual minority men and transgender people in the community and assigned them to use a home-based self-collection swabbing kit or attend a clinic-based swabbing. Swabs were sent for HPV genotyping. The proportions of participants completing screening in each study arm and the adequacy of their specimens for HPV genotyping were assessed. Relative risks were estimated for factors associated with screening. A total of 240 individuals were randomized. Age (median, 46 years) and HIV status (27.1% living with HIV) did not differ by study arm. A total of 89.2% and 74.2% of home-arm and clinic-arm individuals returned the swab, respectively (P = .003), difference between groups, 15.0% (95% CI 5.4%-24.6%). Among black individuals, 96.2% and 63.2% in the home and clinic arms screened (P = .006). Among individuals with HIV, 89.5% and 51.9% in the home and clinic arms screened (P < .001). Self-collected swabs and clinician-collected swabs were comparable in adequacy for HPV genotyping (96.3% and 93.3%, respectively). People at highest risk for anal cancer may be more likely to screen if they are able to self-collect swabs at home rather than attend a clinic., (© 2023 UICC.)

Objective: Multiple organizations recommend an annual digital anal rectal examination (DARE) for people at highest risk for anal cancer. The authors assessed DARE usage among sexual minority men and transgender women., Methods: Community-recruited and asymptomatic individuals from a mid-sized US city were enrolled into the Prevent Anal Cancer Self-Swab Study, a longitudinal clinical trial of anal cancer screening. Self-reported data from the baseline survey were used to assess usage of DARE in the last year and during the lifetime. Adjusted odds ratios (aORs) and CIs for factors associated with each outcome were determined using multivariable logistic regression., Results: Among 241 participants, median age was 46 years (interquartile range, 33-57 years), 27.0% were living with HIV, and 24.5% reported a previous diagnosis of anal warts. A total of 13.7% (95% CI = 9.4%-18.0%) of individuals reported a DARE in the previous year, whereas 53.9% (95% CI = 47.7%-60.2%) reported a DARE during the lifetime. The following were associated with a DARE in the previous year: increasing age (aOR = 1.04; 95% CI = 1.01-1.08 for each additional year), any previous anal cytology (aOR = 2.62; 95% CI = 1.19-5.80, compared with no previous test or no knowledge of a test), and preferred receptive position during anal sex (aOR = 4.93; 95% CI = 1.17-20.86 compared with insertive)., Conclusions: Despite guidelines recommending an annual DARE, it was uncommonly reported. There is an urgent need to understand barriers to conducting DARE among individuals most vulnerable to anal cancer and their health care providers., Competing Interests: The authors have declared they have no conflicts of interest., (Copyright © 2023, ASCCP.)

Background: Radiomics is an approach to medical imaging that quantifies the features normally translated into visual display. While both radiomic and clinical markers have shown promise in predicting response to neoadjuvant chemoradiation therapy (nCRT) for rectal cancer, the interrelationship is not yet clear., Methods: A retrospective, single-institution study of patients treated with nCRT for locally advanced rectal cancer was performed. Clinical and radiomic features were extracted from electronic medical record and pre-treatment magnetic resonance imaging, respectively. Machine learning models were created and assessed for complete response and positive treatment effect using the area under the receiver operating curves., Results: Of 131 rectal cancer patients evaluated, 68 (51.9%) were identified to have a positive treatment effect and 35 (26.7%) had a complete response. On univariate analysis, clinical T-stage (OR 0.46, p = 0.02), lymphovascular/perineural invasion (OR 0.11, p = 0.03), and statin use (OR 2.45, p = 0.049) were associated with a complete response. Clinical T-stage (OR 0.37, p = 0.01), lymphovascular/perineural invasion (OR 0.16, p = 0.001), and abnormal carcinoembryonic antigen level (OR 0.28, p = 0.002) were significantly associated with a positive treatment effect. The clinical model was the strongest individual predictor of both positive treatment effect (AUC = 0.64) and complete response (AUC = 0.69). The predictive ability of a positive treatment effect increased by adding tumor and mesorectal radiomic features to the clinical model (AUC = 0.73)., Conclusions: The use of a combined model with both clinical and radiomic features resulted in the strongest predictive capability. With the eventual goal of tailoring treatment to the individual, both clinical and radiologic markers offer insight into identifying patients likely to respond favorably to nCRT., (© 2022. The Society for Surgery of the Alimentary Tract.)

A 48-year-old female with metastatic colon adenocarcinoma and history of pre-existing coronary vasospasm with ventricular tachycardia (VT) successfully tolerated de novo 5-fluorouracil (5-FU) chemotherapy infusions with prophylactic administration and optimization of anti-spasm medications. 5-FU has been reported to produce severe cardiotoxic side effects, including coronary vasospasm, ventricular arrhythmias, and sudden cardiac death, and is not typically reported in individuals with pre-existing coronary vasospasm., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Background: Current American Society of Colorectal Surgery Clinical Practice Guidelines for Ambulatory Anorectal Surgery endorse use of monitored anesthesia care, general anesthesia, or spinal anesthesia based on physician and patient preference. Although several studies support the use of monitored anesthesia care over general anesthesia, the literature regarding spinal anesthesia is limited and heterogenous due to small sample sizes and disparate spinal anesthesia techniques. Saddle block anesthesia is a form of spinal anesthesia that localizes to the lowermost sacral spinal segments allowing for preservation of lower extremity motor function and faster recovery. We accrued one of the largest reported cohort of anorectal procedures using saddle block anesthesia, as such, we sought to evaluate our institutional 12-year experience., Methods: Patients who underwent a benign anorectal procedure at our outpatient surgery center between July 2008-2020 were retrospectively reviewed. Demographics, surgical factors, perioperative times, and adverse events were collected from the electronic medical records. Saddle block anesthesia was generally performed in the preoperative area using a spinal needle (25-27 gauge) and a single injection technique of a 1:1 ratio local anesthetic mixed with 10% dextrose solution. Between 2.5-5 mg of hyperbaric anesthetic was injected intrathecally in the sitting position and the patient remained upright for 3-10 minutes. This technique of saddle block anesthesia provides analgesia for approximately 1-3 hours., Results: In the study, 859 saddle block anesthesia patients were identified, with a mean age of 44.6 years and American Society of Anesthesia score of 1.9; 609 (70.9%) were male. Surgical indications included lesion removal (27.1%), anal fistula (25.8%), hemorrhoidectomy (24.7%), pilonidal disease (6.3%), anal fissure (5.8%), and a combination of prior (10.2%). Prone jackknife positioning was used in 91.6% of procedures. Saddle block anesthesia most often was performed with bupivacaine (48.9%) or ropivacaine (41.7%). The median procedural saddle block anesthesia time was 11 minutes, surgery time was 17 minutes, anesthesia time was 42 minutes, and recovery time was 91 minutes. Patients spent a median of 3 hours and 53 minutes in the facility. Adverse events included urinary retention (1.9%), conversion to general anesthesia (1.8%), spinal headache (1.5%), hemodynamic instability (0.9%), and injection site reaction (0.3%)., Conclusion: Demonstrated using the largest known cohort of anorectal patients with saddle block anesthesia, saddle block anesthesia provides an effective method of analgesia to avoid general anesthesia with a low rate of adverse events., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: Squamous cell carcinoma of the anus is a common cancer among sexual minority men, especially HIV-positive sexual minority men; however, there is no evidenced-based national screening protocol for detection of anal precancers. Our objective is to determine compliance with annual anal canal self-sampling or clinician-sampling for human papillomavirus (HPV) DNA., Methods and Analysis: This is a prospective, randomised, two-arm clinical study to evaluate compliance with annual home-based versus clinic-based HPV DNA screening of anal canal exfoliated cells. The setting is primary care community-based clinics. Recruitment is ongoing for 400 HIV-positive and HIV-negative sexual minority men and transgender persons, aged > 25 years, English or Spanish speaking, no current use of anticoagulants other than nonsteroidal anti-inflammatory drugs and no prior diagnosis of anal cancer. Participants are randomised to either receive a swab in the mail for home-based collection of an anal canal specimen at 0 and 12 months (arm 1) or attend a clinic for clinician collection of an anal canal specimen at 0 and 12 months (arm 2). Persons will receive clinic-based Digital Anal Rectal Examinations and high-resolution anoscopy-directed biopsy to assess precancerous lesions, stratified by study arm. Anal exfoliated cells collected in the study are assessed for high-risk HPV persistence and host/viral methylation. The primary analysis will use the intention-to-treat principle to compare the proportion of those who comply with 0-month and 12-month sampling in the home-based and clinic-based arms. The a priori hypothesis is that a majority of persons will comply with annual screening with increased compliance among persons in the home-based arm versus clinic-based arm., Ethics and Dissemination: The study has been approved by the Medical College of Wisconsin Human Protections Committee. Results will be disseminated to communities where recruitment occurred and through peer-reviewed literature and conferences., Trial Registration Number: NCT03489707., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Narcotics are the cornerstone of postoperative pain control, but the opioid epidemic and the negative physiological and psychological effects of narcotics implore physicians to utilize nonpharmacological methods of pain control., Objective: This pilot study investigated a novel neurostimulation device for postoperative analgesia. We hypothesized that active neurostimulation would decrease postoperative narcotic requirements., Design: This was a placebo-controlled, double-blinded trial., Settings: This trial was conducted at an academic medical center and a Veterans Affairs hospital., Patients: This trial included adult patients who underwent elective bowel resection between December 2016 and April 2018., Interventions: Patients were randomly assigned to receive an active or inactive (sham) device, which was applied to the right ear before surgery and continued for 5 days., Main Outcome Measures: The primary outcome was total opioid consumption. The secondary outcomes included pain, nausea, anxiety, return of bowel function, complications, 30-day readmissions, and opioid consumption at 2 weeks and 30 days., Results: A total of 57 patients participated and 5 withdrew; 52 patients were included in the analysis. Twenty-eight patients received an active device and 24 received an inactive device. There was no difference in total narcotic consumption between active and inactive devices (90.79 ± 54.93 vs 90.30 ± 43.03 oral morphine equivalents/day). Subgroup analyses demonstrated a benefit for patients after open surgery (p = 0.0278). When patients were stratified by decade, those aged 60 to 70 and >70 years derived a benefit from active devices in comparison with those aged 30 to 40, 40 to 50, and 50 to 60 years old (p = 0.01092). No serious adverse events were related to this study., Limitations: This study was limited by the small sample sizes., Conclusions: No difference in opioid use was found with auricular neurostimulation. However, this pilot study suggests that older patients and those with larger abdominal incisions may benefit from auricular neurostimulation. Further investigation in these high-risk patients is warranted. See Video Abstract at http://links.lww.com/DCR/B452.ClinicalTrials.gov identifier: NCT02892513., Impacto De La Neuroestimulacin Auricular En Pacientes Sometidos a Ciruga Colorrectal Con Un Protocolo De Recuperacin Mejorada Un Ensayo Piloto Aleatorizado Y Controlado: ANTECEDENTES:Los narcóticos son la piedra angular del control del dolor postoperatorio, pero la epidemia de opioides y los efectos fisiológicos y psicológicos negativos de los narcóticos incentivan a los médicos a que utilicen métodos no farmacológicos de control del dolor.OBJETIVO:Este estudio piloto investigó un nuevo dispositivo de neuroestimulación para analgesia postoperatoria. Hipotetizamos que la neuroestimulación activa disminuiría los requerimientos narcóticos postoperatorios.DISEÑO:Este fue un ensayo doble ciego controlado con placebo.ESCENARIO:Esto se llevó a cabo en un centro médico académico y en un hospital de Asuntos de Veteranos (Veterans Affairs hospital).PACIENTES:Este ensayo incluyó pacientes adultos que se sometieron a resección intestinal electiva entre diciembre de 2016 y abril de 2018.INTERVENCIONES:Los pacientes fueron asignados al azar para recibir un dispositivo activo o inactivo (falso), que se aplicó al oído derecho antes de la cirugía y se mantuvo durante 5 días.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el consumo total de opioides; los resultados secundarios incluyeron dolor, náusea, ansiedad, retorno de la función intestinal, complicaciones, reingresos a 30 días y consumo de opioides a 2 semanas y a 30 días.RESULTADOS:Participaron un total de 57 pacientes y 5 se retiraron; Se incluyeron 52 pacientes en el análisis. Veintiocho pacientes recibieron un dispositivo activo y 24 recibieron un dispositivo inactivo. No hubo diferencias en el consumo total de narcóticos entre los dispositivos activos e inactivos (90.79 ± 54.93 vs 90.30 ± 43.03 equivalentes de morfina oral [OME] / día). Los análisis de subgrupos demostraron un beneficio para los pacientes después de cirugía abierta (p = 0.0278). Cuando los pacientes se estratificaron por década, aquellos de 60-70 y > 70 años obtuvieron un beneficio de los dispositivos activos en comparación con los de 30-40, 40-50 y 50-60 años (p = 0.01092). No hubo eventos adversos graves relacionados con este estudio.LIMITACIONES:Este estudio estuvo limitado por los pequeños tamaños de muestra.CONCLUSIONES:No se encontró diferencia en el uso de opioides con la neuroestimulación auricular. Sin embargo, este estudio piloto sugiere que los pacientes mayores y aquellos con incisiones abdominales más grandes pueden beneficiarse de la neuroestimulación auricular. Está justificada la investigación adicional en estos pacientes de alto riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B452. (Traducción-Dr. Jorge Silva Velazco)., (Copyright © The ASCRS 2020.)

Background: Human Papillomavirus (HPV) is known to cause dysplasia and cancer. In cervical disease, there are documented differences in prevalence of HPV genotypes among racial/ethnic groups. Little is known about prevalence of HPV genotypes in anal dysplasia. This study aimed to evaluate association between HPV genotypes and race/ethnicity in a racially heterogenous population with anal dysplasia., Methods: This was a single-institution retrospective review of patients treated for anal dysplasia between 2008 and 2019. HPV genotype, obtained via anal swab testing, was recorded as HPV 16, HPV 18, or other non-16/18 high-risk (HR) HPV genotypes. Univariate and multivariate logistic regression analyses were used to evaluate the association between patient factors and HPV genotype., Results: Of 517 patients meeting inclusion criteria, 46.8% identified as White, 37.1% as Black, 13.2% as Hispanic, and 2.9% as other/unknown. Race/ethnicity (P = 0.016) and sex (P < 0.001) were significantly associated with differences in prevalence of HPV genotypes. Black (odds ratio 1.56, 95% confidence interval 1.00-2.44) and male (odds ratio 2.35, 95% confidence interval 1.42-3.92) patients were significantly more likely to have non-16/18 HR HPV genotypes., Conclusions: In a racially and socioeconomically diverse cohort of patients with anal dysplasia, Black race and male sex were associated with increased likelihood of infection with a non-16/18 HR HPV genotype. Many of these genotypes are not covered by currently available vaccines. Further study is warranted to evaluate anal HPV genotypes in a larger cohort, as this may have important implications in HPV vaccination and anal dysplasia screening efforts., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The robotic platform is increasingly used in colorectal surgery. Recent upgrades in the robotic platform and introduction of proctectomy-specific reports from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) warrant updated evaluation of minimally invasive proctectomy outcomes. The aim of this study was to compare outcomes in robotic versus laparoscopic proctectomy using ACS-NSQIP data., Materials and Methods: The ACS-NSQIP data set was used to identify adult patients undergoing elective robotic and laparoscopic proctectomy in 2016 and 2017. Demographics, preoperative and intraoperative data, and postoperative outcomes were collected. Propensity-weighted analysis was used to estimate the effect of robotic versus laparoscopic surgery on outcomes., Results: Of 3845 patients meeting inclusion criteria, 2681 (70%) underwent a laparoscopic approach and 1164 (30%) underwent a robotic approach. Patients undergoing a robotic procedure were more likely to be older, have higher American Society of Anesthesiologists scores, low rectal tumors, and have undergone chemotherapy or radiation before surgery. After propensity adjustment, a robotic approach was associated with a decrease in conversion to open operation (estimated mean difference, -6.7%; P < 0.01), length of stay (-0.6 d; P = 0.01), occurrence of postoperative ileus (-3.7%; P = 0.01), and an increase in operative time (20.3 min; P < 0.01)., Conclusions: Using data from a national cohort, we found that compared with laparoscopy, robotic proctectomy is associated with decreased conversion to open operation, longer operation time, decreased length of stay, and decreased postoperative ileus. Our study identified several advantages to a robotic approach; however, further work is needed to assess cost-effectiveness in conjunction with clinical outcomes., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Left hemicolectomy and complicated sigmoid colectomy require an anastomosis between the transverse colon and rectum. Generous mobilization will typically allow the colon to reach to the rectum. However, despite full mobilization of the splenic flexure and extensive work on the mesentery, there are cases in which reach to the pelvis is still an issue. Retroileal routing of the colon is one technique for overcoming such a reach problem and achieving a tension-free anastomosis. Performing retroileal routing using laparoscopic techniques has been reported rarely, and to date, there are no data on this technique when performed in a hand-assisted laparoscopic fashion. This study aimed to describe the feasibility of doing a retroileal routing using a hand-assisted laparoscopic technique., Methods: This was a retrospective chart review of patients who underwent a colon or rectal resection, either open or laparoscopic, with a pelvic anastomosis, by a single colorectal surgeon at an academic institution between 2008 and 2015 with a focus on the immediate and long-term postoperative complications, estimated blood loss, and operating room time for patients having an operation that included retroileal routing for construction of a colorectal anastomosis., Results: A total of 340 patients fit inclusion criteria and of these, 13 underwent hand-assisted laparoscopic procedures with retroileal routing of the proximal colon to the colorectal anastomosis. Postoperative morbidity included intubation for CO 2 retention in one patient and a RLL effusion in another patient; there were no anastomotic leaks. Long-term morbidities included two ventral hernias at 2 years postoperatively. Mean operating room time was 208 min. There were no 30- or 90-day mortalities., Conclusions: Hand-assisted laparoscopic retroileal routing is a feasible and safe technique in accomplishing a tension-free colorectal anastomosis when proximal colon length makes standard routing of the colon to the rectum an issue.

Background: Current treatment for locally advanced rectal cancer includes neoadjuvant chemoradiation followed by surgery and adjuvant chemotherapy. With neoadjuvant chemotherapy (NC), both chemoradiation and chemotherapy are given in the neoadjuvant setting. This study aims to assess patterns of NC utilization and differences in treatment response compared with standard treatment at our institution., Materials and Methods: We performed a retrospective review of patients treated for stage II-III rectal cancer at our institution between 2008 and 2018, examining patient demographics, tumor characteristics, and treatment modality. The primary outcome of interest was complete response (CR) to treatment, including both pathologic and clinical CR., Results: Of 184 patients, 134 (72.8%) received standard therapy, and 50 (27.2%) received NC. In the standard treatment group, 70.1% were node positive, and 9.0% had T4-disease, compared with 92.0% and 26.0% in the NC group, respectively (both P < 0.01). NC utilization increased over time, with 3.4% of patients receiving NC between 2008 and 2012, compared with 48.5% in 2013-2018 (P < 0.01). CR was achieved in 19.4% versus 34.0% (P < 0.01) of patients in standard versus NC groups. With multivariate analysis, NC (odds ratio = 3.02 [95% confidence interval 1.37-6.67], P = 0.01) was associated with increased likelihood of achieving CR, whereas higher T-stage was associated with decreased likelihood of CR (for cT4, odds ratio = 0.06 [95% confidence interval 0.01-0.56], P = 0.01)., Conclusions: Use of NC was increasingly used at our institution from 2008 to 2018. Patients who received NC achieved higher rates of CR compared with those undergoing standard therapy, despite having more advanced disease. These data support trends from other institutions and provides rationale for further study regarding use of NC for locally advanced rectal cancer., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Alvimopan has been shown to reduce length of stay after bowel resection. Use remains variable among institutions due to cost and efficacy concerns in laparoscopic surgery. Additionally, alvimopan's effects have not been isolated from other medications within enhanced recovery protocols. The aim of this study was to distinguish the relationship between alvimopan use, length of stay, and cost in both open and laparoscopic segmental colectomies., Methods: The Vizient dataset was queried to identify patients undergoing open and laparoscopic colectomies from 2015 to 2017. Patient demographics and treatment details were collected. Primary outcomes of interest included duration of stay and total direct costs., Results: In the study, 12,727 patients met inclusion criteria and 3,358 (26.4%) received alvimopan. For both open and laparoscopic groups, alvimopan was associated with decreased length of stay in unadjusted (4.0 vs 6.0 days, P < .01 and 3.0 vs 4.0 days, P < .01, respectively) and adjusted analysis (effect ratio 0.79, P < .01 and 0.85, P < .01, respectively). Alvimopan was associated with a 7% decrease in direct cost after adjustment (effect ratio 0.93, P = .04), with no cost difference in laparoscopic procedures (effect ratio 0.99, P = .71)., Conclusion: Alvimopan use is associated with decreased length of stay for both open and laparoscopic colon resections, decreased cost in open procedures, and no cost difference for laparoscopic procedures., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Human papillomavirus is a common sexually transmitted infection that may affect the oropharynx, genitalia, or anus. Some strains of this virus may cause bulky growths around the anus known as giant anal condylomas. These can become large, disfiguring, and may cause bleeding, as well as difficulty with defecation and hygiene. Surgical management is usually necessary for large condylomas, whereas office-based procedures are common for smaller lesions. It is unclear why some develop large anal margin tumors, whereas others develop limited disease. The aim of the present study was to evaluate for risk factors that may play a role in the development of extensive disease warranting operative management., Materials and Methods: A retrospective chart review of patients seen within the Anal Dysplasia Clinic at the Medical College of Wisconsin was undertaken. Clinic encounters for patients with anogenital condyloma were abstracted for demographic information, operative interventions, Human Immunodeficiency Virus status, and smoking history to determine risk factors that predicted operative intervention for giant anal condylomas., Results: A total of 239 patients met inclusion criteria; 211 (88.3%) were male and 28 (11.7%) were female. Racial makeup of the cohort included 49% Caucasian, 38.9% African-American, 9.2% Hispanic, and 2.9% were identified as another ethnicity. One hundred forty-three patients (60.1%) were current or past smokers. One hundred ninety-eight (82.8%) patients tested positive for human immunodeficiency virus (HIV), whereas 41 (17.2%) were negative. Multiple linear regression identified only African-American race as predictive of greater disease burden., Conclusions: African-American race was associated with increased size of anal condyloma. As the size of anal condylomas increase, management shifts from topical treatments to operative intervention. This is the first study to correlate race with burden of disease in the general population., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Aortic graft infections are a rare but devastating complication of aortic revascularization. Often infections occur due to contamination at the time of surgery. Iatrogenic misplacement of the limbs of an aortobifemoral graft is exceedingly rare, and principles of evaluation and treatment are not well defined. We report 2 cases of aortobifemoral bypass graft malposition through the colon., Case Report: Case 1 is a 54-year-old male who underwent aortobifemoral bypass grafting for acute limb ischemia. He had previously undergone a partial sigmoid colectomy for diverticulitis. Approximately 6 months after vascular surgery, he presented with an occult graft infection. Preoperative imaging and intraoperative findings were consistent with graft placement through the sigmoid colon. Case 2 is a 60-year-old male who underwent aortobifemoral bypass grafting due to a nonhealing wound after toe amputation. His postoperative course was complicated by pneumonia, bacteremia thought to be secondary to the pneumonia, general malaise, and persistent fevers. Approximately 10 weeks after the vascular surgery, he presented with imaging and intraoperative findings of graft malposition through the cecum., Conclusions: Aortic graft infection is usually caused by surgical contamination and presents as an indolent infection. Case 1 presented as such; Case 2 presented more acutely. Both grafts were iatrogenically misplaced through the colon at the index operation. The patients underwent extra-anatomic bypass and graft explantation and subsequently recovered.

Background: Restorative proctocolectomy with IPAA improves quality of life in patients with medically refractory ulcerative colitis. Although bowel obstruction is common, pouch volvulus is rare and described only in case reports. Diagnosis can be challenging, resulting in delayed care and heightened morbidity., Objective: The purpose of this study was to delineate the symptoms and successful management strategies used in patients with IPAA volvulus that result in pouch salvage., Design: This study was a case series., Settings: The study was conducted at a tertiary referral center for ulcerative colitis in Milwaukee, Wisconsin., Patients: Patients included those with volvulus of the IPAA., Main Outcome Measures: Over the study period (2010-2015), 6 patients were diagnosed with IPAA volvulus. The primary outcomes were symptom manifestation, diagnostic practices, and treatment of pouch volvulus., Results: Six patients with ulcerative colitis were identified with pouch volvulus. The majority (n = 4) underwent a laparoscopic pouch creation and had early symptom manifestation after surgery. Complications preceding volvulus included pouch ulceration (n = 5) and pouchitis (n = 4). The most common presenting symptoms of volvulus were abdominal pain (n = 4) and obstipation (n = 4). Multiple imaging modalities were used, but volvulus was most frequently identified by CT scan. Management was primarily operative (n = 5), composed of excision of the pouch (n = 3), pouch-pexy (n = 1), and detorsion with defect closure (n = 1). Both operative and nonoperative treatment with endoscopic detorsion resulted in low morbidity and improved patient symptoms., Limitations: This single-institution study is limited by its retrospective design and small number of patients., Conclusions: IPAA volvulus is a rare and challenging cause of bowel obstruction in ulcerative colitis. Heralding signs and symptoms, such as pouch ulceration and acute obstipation, should initiate a workup for a twisting pouch. Diagnosis, which is multimodal, must occur early to avert necrosis and allow for preservation of a well-functioning pouch. See Video Abstract at http://links.lww.com/DCR/A561.

Background: The risk of postoperative venous thromboembolism is high in patients with colon cancer and IBD. Although The American Society of Colon and Rectal Surgeons suggests posthospital prophylaxis after surgery in patients with colon cancer, there are no such recommendations for patients with IBD., Objective: This study aims to analyze the incidence and risk factors for postoperative venous thromboembolism., Design: This was a retrospective review using the Explorys platform., Settings: Aggregated electronic medical records from 26 major health care systems across the United States from 1999 to 2017 were used for this study., Patients: Patients who underwent colon surgery were included., Main Outcome Measures: Patients were followed up to 90 days postoperatively for deep vein thrombosis and pulmonary embolism., Results: A total of 75,620 patients underwent colon resections, including 32,020 patients with colon cancer, 9850 patients with IBD, and 33,750 patients with diverticulitis. The 30-day incidence of venous thromboembolism was higher in patients with cancer and IBD than in patients with diverticulitis (2.9%, 3.1%, and 2.4%, p < 0.001 for both comparisons). The 30-day incidence of venous thromboembolism in patients with ulcerative colitis is greater than in patients with Crohn's disease (4.1% vs 2.1%, p < 0.001). The cumulative incidence of venous thromboembolism increased from 1.2% at 7 days after surgery to 4.3% at 90 days after surgery in patients with cancer, and from 1.3% to 4.3% in patients with IBD. In multivariable analysis, increase in the risk of venous thromboembolism was associated with cancer diagnosis, IBD diagnosis, age ≥60, smoking, and obesity., Limitations: This study was limited by its retrospective nature and by the use of the aggregated electronic database, which is based on charted codes and contains only limited collateral clinical data., Conclusions: Because of the elevated and sustained risk of postoperative thromboembolism, patients with IBD, especially ulcerative colitis, might benefit from extended thromboembolism prophylaxis similar to that of patients with colon cancer. See Video Abstract at http://links.lww.com/DCR/A544.

Background: Enhanced recovery pathways have decreased length of stay after colorectal surgery. Loop ileostomy closure remains a challenge, because patients experience high readmission rates, and validation of enhanced recovery pathways has not been demonstrated. This study examined a protocol whereby patients were discharged on the first postoperative day and instructed to advance their diet at home with close telephone follow-up., Objective: The hypothesis was that patients can be safely discharged the day after loop closure, leading to shorter length of stay without increased rates of readmission or complications., Design: Patients undergoing loop ileostomy closure were queried from the American College of Surgeons National Surgical Quality Improvement Project and compared with a single institution (2012-2015). Length of stay, 30-day readmission, and 30-day morbidity data were analyzed., Settings: The study was conducted at a tertiary university department., Patients: The study includes 1602 patients: 1517 from the National Surgical Quality Improvement Project database and 85 from a single institution., Main Outcome Measures: Length of stay and readmission rates were measured., Results: Median length of stay was less at the single institution compared with control (2 vs 4 d; p < 0.001). Thirty-day readmission (15.3% vs 10.4%; p = 0.15) and overall 30-day complications (15.3% vs 16.7%; p = 0.73) were similar between cohorts. Estimated adjusted length of stay was less in the single institution (2.93 vs 5.58 d; p < 0.0001). There was no difference in the odds of readmission (p = 0.22)., Limitations: The main limitations of this study include its retrospective nature and limitations of the National Surgical Quality Improvement Program database., Conclusions: Next-day discharge with protocoled diet advancement and telephone follow-up is acceptable after loop ileostomy closure. Patients can benefit from decreased length of stay without an increase in readmission or complications. This has the potential to change the practice of postoperative management of loop ileostomy closure, as well as to decrease cost. See Video Abstract at http://links.lww.com/DCR/A310.

Background: Anastomotic leak after colorectal resection increases morbidity, mortality, and in the setting of cancer, increases recurrences rates and reduces survival odds. Recent reports suggest that fluorescence evaluation of perfusion after colorectal anastomosis creation is associated with low anastomotic leak rates (1.4%). The purpose of this work was to evaluate whether a similar low anastomotic leak rate after left-sided colorectal resections could be achieved using standard assessment of blood flow to the bowel ends., Methods: We performed a retrospective chart review at an academic tertiary referral center, evaluating 317 consecutive patients who underwent a pelvic anastomosis after sigmoid colectomy, left colectomy, or low anterior resection. All operations were performed by a single surgeon from March 2008 to January 2015 with only standard clinical measures used to assess perfusion to the bowel ends. The primary outcome measure was the anastomotic leak rate as diagnosed by clinical symptoms, exam, or routine imaging., Results: The average patient age was 59.7 years with an average body mass index of 28.8 kg/m(2). Rectal cancer (128, 40.4%) was the most common indication for operation while hypertension (134, 42.3%) was the most common comorbidity. In total, 177 operations were laparoscopic (55.8%), 13 were reoperative resections (4.1%), and 108 were protected with a loop ileostomy (34.1%). Preoperative chemotherapy was administered to 25 patients (7.9%) while preoperative chemo/radiation was administered to 64 patients (20.2%). The anastomotic leak rate was 1.6% (5/317)., Conclusion: Our data suggests that standard, careful evaluation of adequate blood flow via inspection and confirmation of pulsatile blood flow to the bowel ends and meticulous construction of the colorectal or coloanal anastomoses can result in very low leak rates, similar to the rate reported when intraoperative imaging is used to assess perfusion., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Outcomes for rectal cancer surgery have improved significantly over the past 20 years with increasing rates of survival and recurrence, specifically local recurrence. These gains have been realized during a period of time in which there has been an increasing emphasis on sphincter preservation. As we have become increasingly aggressive in avoiding resection of the anus, we have begun accepting bowel dysfunction as a normal outcome. Low anterior resection syndrome, defined as a constellation of symptoms including incontinence, frequency, urgency, or feelings of incomplete emptying, has a significant impact on quality of life and results in many patients opting for a permanent colostomy to avoid these symptoms. In this article, we will highlight the most recent clinical and basic science research on this topic and discuss areas of future investigation.

Background: Patients with an incomplete colonoscopy are potentially at risk for missed lesions., Objective: The purpose of this work was to identify the percentage of patients completing colonic evaluation after incomplete colonoscopy, the manner in which the evaluation was completed, and the incidence of significant pathology., Design: This was a retrospective analysis of prospectively collected data., Settings: The study was conducted in an outpatient colonoscopy clinic in the colorectal surgery department of a tertiary referral center., Patients: Patients included those undergoing incomplete colonoscopy from a database of 25,645 colonoscopies performed from 1982 to 2009., Interventions: Procedures aimed at completing colorectal evaluation were included in the study., Main Outcome Measures: Reason for incompletion, secondary study, its success, and findings were measured., Results: A total of 242 patients with incomplete colonoscopies were identified; 166 (69%) were women. The average age of patients was 59 years. Most frequent causes for incomplete colonoscopy were inadequate preparation (34%), pain (30%), and tortuosity (20%). The scope could not pass the splenic flexure in 165 patients (71%). A total of 218 patients (90%) were offered completion studies, and 179 patients (82%) complied. Seventy-three of 82 patients who had a surveillance colonoscopy had a follow-up (89%), compared with 72 (87%) of 83 with symptoms and 40 (74%) of 54 who had a screening. Barium enema (BE) was performed in 74 (41%), repeat colonoscopy in 71 (40%), CT colonography in 17 (9%), and colonoscopy under general anesthesia in 9 patients (5%). Resection with intraoperative/perioperative colonoscopy was required in 8 patients (4%). Repeat colonoscopy found 32 lesions (24 tubular adenomas, 4 tubulovillous adenomas, and 4 sessile serrated polyps) in 17 patients (24%). Radiology demonstrated new abnormalities in 11 (12%) of 91 patients, prompting 7 colonoscopies. In 3 patients, colonoscopy showed an inverted appendix, a tubulovillous adenoma, and a sigmoid stricture. Overall, clinically significant lesions were found in 19 patients (10%)., Limitations: This study was limited by an incomplete colonoscopy subjectively determined at the time of colonoscopy, as well as by a lack of comparison group., Conclusions: Complete colonic evaluation in patients with an incomplete colonoscopy is important. Repeat colonoscopy may be the most efficient way to achieve this.

Intra-abdominal infections are a common problem for the general surgeon and major sources of morbidity and mortality in the intensive care unit. Some of these patients present with peritonitis that can rapidly progress to septic shock. The basic principles of care include prompt resuscitation, antibiotics, and source control. This article will use a detailed case study to outline the management of a patient with severe intra-abdominal infection from diverticulitis from initial resuscitation to reconstruction. Components of the Surviving Sepsis Campaign as they pertain to surgical patients are discussed and updated, and the concept of damage control general surgery is applied., (Copyright © 2012. Published by Elsevier Inc.)

Background: Clinical studies show that disturbed colonic motility induced by extrinsic nerves damage is restored over time. We studied whether 5-HT3 and 5HT4 receptors are involved in mediating the adaptive mechanisms following parasympathetic denervation., Methods: Parasympathetic denervation of the entire colon was achieved by bilateral pelvic nerve transection and truncal vagotomy in rats. Colonic transit was measured by calculating the geometric center (GC) of 51Cr distribution. Expression of 5-HT3 and 5HT4 receptor mRNA was determined by real time RT-PCR., Results: Parasympathetic denervation caused a significant delay in colonic transit (GC=4.36) at postoperative day (POD) 1, compared with sham operation (GC=6.31). Delayed transit was gradually restored by POD 7 (GC=5.99) after the denervation. Restored colonic transit was antagonized by the administration of 5-HT3 and 5HT4 receptors antagonists at POD 7. 5-HT3 and 5HT4 receptors mRNA expression were significantly increased in the mucosal/submucosal layer at POD 3 or POD 7, whereas no significant difference was observed in the longitudinal muscle layers adherent with the myenteric plexus (LMMP)., Conclusions: It is suggested that up-regulation of 5-HT3 and 5-HT4 receptors expression in the mucosal/submucosal layer is involved to restore the delayed transit after the parasympathetic denervation in rats., (Published by Elsevier Inc.)

Introduction: Injury to pelvic sympathetic and parasympathetic nerves from surgical and obstetrical trauma has long been cited as a cause for abnormal colorectal motility in humans. Using a rat model, acute transaction of these extrinsic nerves has been shown to effect colorectal motility. The aim of this study is to determine in a rat model how transection of these extrinsic nerves affects colonic transit over time., Methods: Eighty-two Sprague-Dawley rats underwent placement of a tunneled catheter into the proximal colon. Bilateral hypogastric, pelvic nerves (HGN and PN) or both were transected in 66 rats. The remaining 16 rats received a sham operation. Colonic transit was evaluated at postoperative days (PODs) 1, 3, and 7 by injecting and calculating the geometric center (GC) of the distribution of (51)Cr after 3 h of propagation., Results: At POD 1, transection of PNs significantly delayed colonic transit (GC = 4.9, p < 0.05), while transection of HGNs (GC = 8.5, p < 0.05) or transection of both nerves (GC = 7.8, p < 0.05) significantly accelerated colonic transit, when compared with sham operation (GC = 6.0). A significant trend toward recovery was noted in both the HGN and PN transection groups at POD 7., Conclusions: Damage to the extrinsic sympathetic and/or parasympathetic PNs affects colonic transit acutely. These changes in large bowel motor function normalize over time implicating a compensatory mechanism within the bowel itself.

Objective: Interstitial cells of Cajal (ICC) have been endowed with considerable intrinsic plasticity. Blockade of the c-kit signaling pathway results in the shift of ICC towards a smooth muscle-like phenotype. Little is known about stem cell factor (SCF), the ligand of c-kit, and the role it plays in the process of restoration. The aim of this study was to determine whether exogenous SCF can promote ICC replenishment following the blockade of c-kit signaling., Material and Methods: Neutralizing anti-c-kit monoclonal antibody (ACK2) was administered to mice for 8 days after birth. Jejunal muscle strips were cultured up to 7 days. Electrical rhythmic changes were monitored and ICC were examined by immunohistochemistry. Expression of c-kit mRNA was detected by reverse transcriptase-polymerase chain reaction, and expression of Kit protein was detected by Western blot., Results: When c-kit receptors were blocked, ICC nearly disappeared from the jejunum accompanied by the loss of electrical slow waves. By day 7, after in vitro culture with SCF (100 ng/ml), the amplitude of muscle strip slow waves was restored to 0.19 +/- 0.07 mV (p < 0.05), whereas the frequency recovered to 13.7 +/- 3.32/min (p < 0.01). Furthermore, labeling for c-kit(+) cells in the myenteric plexus increased and c-kit mRNA and protein expression were up-regulated compared to that of non-treatment with SCF., Conclusions: The c-kit signaling pathway, activated by SCF, is the critical pathway associated with the control of ICC survival and proliferation. The restoration of ICC number and jejunal electrical rhythm, resulting from blockade of the c-kit signaling pathway, could be facilitated by local SCF administration.

Background: Several disease processes of the colon and rectum, including constipation and incontinence, have been associated with abnormalities of the autonomic nervous system. However, the autonomic innervation to the colon and rectum are not fully understood. The aims of this study were to investigate the effect of stimulation of vagus nerves, pelvic nerves (PN) and hypogastric nerves (HGN) on colorectal motility in rats., Methods: Four strain gauge transducers were implanted on the proximal colon, mid colon, distal colon and rectum to record circular muscle contractions in rats. Electrical stimulation was administered to the efferent distal ends of the cervical vagus nerve, PN and HGN. Motility index (MI) was evaluated before and during stimulation., Key Results: Electrical stimulation (5-20 Hz) of the cervical vagus elicited significant contractions in the mid colon and distal colon, whereas less pronounced contractions were observed in the proximal colon. Pelvic nerves stimulation elicited significant contractions in the rectum as well as the mid colon and distal colon. Atropine treatment almost completely abolished the contractions induced by vagus nerve and PN stimulation. Hypogastric nerves stimulation caused relaxations in the rectum, mid colon and distal colon. The relaxations in response to HGN stimulation were abolished by propranolol., Conclusions & Inferences: Vagal innervation extends to the distal colon, while the PN has projections in the distribution of the rectum through the mid colon. This suggests a pattern of dual parasympathetic innervation in the left colon. Parasympathetic fibers regulate colorectal contractions via muscarinic receptors. The HGN mainly regulates colorectal relaxations via beta-adrenoceptors.

Introduction: The colon and rectum are regulated by the autonomic nervous system (ANS). Abnormalities of the ANS are associated with diseases of the colon and rectum while its modulation is a putative mechanism for sacral nerve stimulation. The purpose of this study is to establish a rat model elucidating the role of the efferent ANS on rectal motility., Materials and Methods: Rectal motility following transection or stimulation of parasympathetic pelvic nerves (PN) or sympathetic hypogastric nerves (HGN) was measured with rectal strain gauge transducers and quantified as a motility index (MI). Colonic transit was measured 24 hours after transection by calculating the geometric center (GC) of distribution of (51)Cr, Results and Discussion: Transection of PN and HGN decreased MI to 518 +/- 185 g*s (p < 0.05) and increased MI to 5,029 +/- 1,954 g*s (p < 0.05), respectively, compared to sham (975 +/- 243 g*s). Sectioning of PN and HGN decreased transit with GC = 4.9 +/- 0.2 (p < 0.05) and increased transit with GC = 8.1 +/- 0.7 (p < 0.02), respectively, compared to sham (GC = 5.8 +/- 0.3). Stimulation of PN and HGN increased MI to 831 +/- 157% (p < 0.01) and decreased MI to 251 +/- 24% (p < 0.05), respectively., Conclusion: Rectal motility is significantly altered by sectioning or stimulating either HGN or PN. This model may be useful in studying how sacral nerve stimulation exerts its effects and provide insight into the maladies of colonic motility.