Impact of bariatric surgery on early-onset colorectal cancer risk: a systematic review and meta-analysis.

The aim of this meta-analysis is to determine the impact of bariatric surgery on the risk of early-onset colorectal neoplasia. This systematic review was conducted according to PRISMA recommendations. It was registered in the PROSPERO international database. A comprehensive search was conducted in electronic databases (MEDLINE, EMBASE, and Web of Science) for completed studies until May 2022. The Search was made using a mixture of indexed terms and title, abstract and keywords. The search included terms: obese, surgical weight loss intervention, colorectal cancer, and colorectal adenomas. Studies that included bariatric intervention patient's vs non-surgical obese patients younger than 50 years were considered. Inclusion criteria were patients with BMI more than 35 kg/m2 who underwent a colonoscopy. Studies with follow-up colonoscopy performed in less than 4 years after bariatric surgery and those that evaluated patients with a mean age difference of 5 or more years between groups were excluded. Outcomes analyzed in obese patients with surgical treatment vs control patients included colorectal cancer incidence. From 2008 to 2021, a total of 1536 records were identified. Five retrospective studies that included 48,916 patients were analyzed. Follow-up period ranged from 5 to 22.2 years. 20,663 (42.24%) patients underwent bariatric surgery and 28,253 (57.76%) were part of the control patients. Roux-en-Y gastric bypass was performed in 14,400 (69.7%) individuals. The intervention and control group were similar in age range, proportion of female participants and initial body mass index (35-48.3 vs 35-49.3, respectively). 126/20663 (0.61%) patients in the bariatric surgery group and 175/28253 (0.62%) individuals in the control group presented CRC. In this meta-analysis, we were unable to demonstrate a significant impact of the Bariatric Surgery on EOCRC risk. Prospective trials with longer follow-up periods should be done to prove the colorectal cancer risk reduction.

Population-based study of outcomes following an initial acute diverticular abscess.

BACKGROUND: Studies examining long-term outcomes following resolution of an acute diverticular abscess have been limited to single-institution chart reviews. This observational cohort study compared outcomes between elective colectomy and non-operative management following admission for an initial acute diverticular abscess. METHODS: The Statewide Planning and Research Cooperative System was queried for unscheduled admissions for an initial acute diverticular abscess in 2002-2010. Bivariable and propensity-matched multivariable analyses compared stoma rates and use of healthcare in patients who had an elective resection and those receiving non-operative management. Diverticulitis recurrence rates were analysed for non-operative management. RESULTS: Among 10 342 patients with an initial acute diverticular abscess, one-third (3270) underwent surgical intervention within 30 days despite initial non-operative management. Of the remaining 7072 patients, 1660 had an elective colectomy within 6 months. Of 5412 patients receiving non-operative management, 1340 (24·8 per cent) had recurrence of diverticulitis within 5 years (median 278 (i.q.r. 93·5-707) days to recurrence). Elective colectomy was associated with higher stoma rates (10·0 per cent, compared with 5·7 per cent for non-operative observation, P < 0·001; odds ratio 1·88, 95 per cent c.i. 1·50 to 2·36), as well as more inpatient hospital days for diverticulitis-related admissions (mean 8·0 versus 4·6 days respectively, P < 0·001; incidence rate ratio (IRR) 2·16, 95 per cent c.i. 1·89 to 2·47) and higher mean diverticulitis-related cost (€70 107 versus €24 490, P < 0·001; IRR 3·11, 2·42 to 4·01). CONCLUSION: Observation without elective colectomy following resolution of an initial diverticular abscess is a reasonable option with lower healthcare costs than operation.

Surgery beyond the visible light spectrum: theoretical and applied methods for localization of the male urethra during transanal total mesorectal excision.

The risk of urethral injury during transanal total mesorectal excision (taTME) is delineated, and potential risk factors for iatrogenic transection are reviewed. A variety of applied and theoretical techniques can be used by surgeons to diminish the risk of injury in males undergoing this operation. Many of the approaches utilize non-optic media and wavelengths beyond the visible light spectrum which can enhance the surgeon's frame of reference. The aim of the present study was to assess the techniques and theoretical approaches to urethral localization during taTME. Future directions in surgical imaging are also discussed, including the use of organic dyes, quantum dots, and carbon nanotubes; collectively, technology that could someday provide surgeons with an ability to identify anatomic structures prone to injury.

Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery.

Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

Association between operative approach and complications in patients undergoing Hartmann's reversal.

BACKGROUND: Complications following reversal of Hartmann's procedure are common, with morbidity rates of up to 50 per cent, and a mortality rate as high as 10 per cent. This is based on case series with heterogeneous data collection and analysis. This study determined risk factors for complications following Hartmann's reversal. METHODS: Patients who underwent elective open and laparoscopic Hartmann's reversal were identified from the American College of Surgeons National Surgical Quality Improvement Program database (2005-2010). The programme collects patient demographics, preoperative medical history, clinical findings and laboratory investigations. Postdischarge data were obtained by a certified reviewer. Complications were categorized as major, septic or incisional. Risk-adjusted 30-day outcomes were assessed by univariable and multivariable analyses, adjusting for patient characteristics, co-morbidity and operative approach. RESULTS: During the study period 7996 patients had a Hartmann's procedure and 2567 cases of Hartmann's reversal were identified, including 336 laparoscopic procedures (13·1 per cent). Major, septic and incisional complication rates were 13·3, 8·5 and 15·7 per cent respectively, with a mortality rate of 0·5 per cent. A laparoscopic approach was found to be independently associated with fewer major (odds ratio (OR) 0·53, 95 per cent confidence interval 0·34 to 0·81), septic (OR 0·48, 0·27 to 0·83) and incisional (OR 0·54, 0·37 to 0·80) complications. A history of chronic obstructive pulmonary disease (OR 1·78-2·00), steroid use (OR 1·75), body mass index at least 30 kg/m² (OR 1·48), diabetes (OR 1·40), smoking (OR 1·33-1·40), American Society of Anesthesiologists fitness grade III and IV (OR 1·46-1·48) and prolonged operating time (OR 1·02) were other factors associated with complications. CONCLUSION: A laparoscopic approach to Hartmann's reversal was associated with fewer complications than open surgery in this highly selected group of patients.

Closure of defunctioning loop ileostomy is associated with considerable morbidity.

AIM: An elective defunctioning ileostomy is commonly employed to attenuate the morbidity that may arise from distal anastomotic leakage. The magnitude of risk associated with subsequent ileostomy closure is difficult to estimate as many of the data arise from small series. This study looked at the rate of complications and predictive factors in a large series of patients. METHODS: The National Surgical Quality Improvement Program database was queried for patients who had an elective closure of ileostomy between 2005 and 2010. Patient demographics, preoperative risk factors and operative variables were recorded. The primary outcome was occurrence of major (mortality, sepsis, return to the operating room, renal failure, major cardiac, neurological or respiratory episode) or minor (wound infection, urinary tract infection) complications within 30 days. Univariate and multivariate regression was used to evaluate the effect of these clinical factors on the complication rate. RESULTS: In total, 5401 patients underwent closure of ileostomy, of whom 502 (9.3%) patients had major complications. The incidence of minor complications was 8.4% (452 patients). There were 32 (0.6%) deaths. American Society of Anesthesiologists grade, functional status, prolonged operative time, history of chronic obstructive pulmonary disease, dialysis and disseminated cancer were independent predictors of major complications. There was no significant increase in complication rates in patients over the age of 80. Major complications were associated with a significant increase in postoperative stay (13.9 vs 4.7 days, P < 0.0001). CONCLUSION: Closure of ileostomy is associated with a significant complication rate. It may use as many resources as the primary surgery and is not a minor follow-up operation.

Prognostic significance of lymph node ratio in patients undergoing abdominoperineal resection of rectum.

BACKGROUND: Lymph node ratio (LNR) has been shown to be an independent prognostic factor in stage III colorectal cancer. Abdominoperineal resection (APR) of rectum is historically associated with poorer oncological outcomes compared to other colorectal resections, and significance of LNR in this group of patients has not been studied. OBJECTIVE: Our aim was to determine impact of LNR on oncological outcomes in a series of patients with rectal cancers undergoing APR. PATIENTS AND METHODS: A series of patients who had undergone APR and had lymph node metastasis were identified from a prospectively maintained clinical, histopathological and radiological database. LNR was calculated, and Cox regression was used to determine the impact of factors affecting local recurrence, distal metastases and overall survival. RESULTS: Fifty-eight (42 males) patients were identified to have rectal cancer with lymph node involvement. LNR was an independent predictor of distal metastasis and overall survival at cutoff levels of 0.17, 0.41 and 0.69. CONCLUSION: Lymph node ratio is an independent predictor of survival outcomes in patients with stage III tumours undergoing APR. LNR may help improve stratification of this group of patients.

A laparoscopic approach reduces short-term complications and length of stay following ileocolic resection in Crohn's disease: an analysis of outcomes from the NSQIP database.

AIM: Studies to date examining the impact of laparoscopy in resection for Crohn's disease on short-term morbidity have been limited by small study populations. The aim of this study was to establish the impact of the operative approach (laparoscopic or open) on outcomes after ileocolic resection for Crohn's disease. METHOD: Ileocolic resections for Crohn's disease were identified using Current Procedural Terminology (CPT) and International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes from the National Surgical Quality Improvement Program (NSQIP) database (2005-2009). Complications were categorized as major (organ system damage and systemic sepsis) or minor (incisional and urinary infections). Multivariate 30-day outcomes and length of stay were determined using linear models adjusting for patient characteristics, comorbidities and operative approach. RESULTS: Of 1917 ileocolic resections, 644 (34%) were performed laparoscopically. At baseline, the open group was significantly older, had more comorbidities, higher American Society of Anesthesiology (ASA) classes, and more intra-operative transfusions (all variables, P<0.05). On multivariate analysis, laparoscopic ileocolic resections were associated with a decrease in major (OR=0.629, 95% CI: 0.430-0.905, P=0.014) and minor (OR=0.576, 95% CI: 0.405-0.804, P=0.002) complications compared with open resections. Laparoscopy was associated with a significant reduction in adjusted length of stay compared with the open approach (-1.08±0.29 days, P=0.0002). CONCLUSION: After adjusting for comorbidities and perioperative factors, such as preoperative sepsis, higher ASA class and higher transfusion rates in the open group, laparoscopic ileocolic resection for Crohn's disease was found to be a safer choice than the open approach, resulting in fewer complications and length of stay. All other things being equal, such patients should be offered the laparoscopic approach as a first-choice option.

It's the procedure not the patient: the operative approach is independently associated with an increased risk of complications after rectal prolapse repair.

AIM: This study compares 30-day outcomes following rectal prolapse repair, examining potential surgical and patient factors associated with perioperative complications. METHOD: Using the NSQIP database, patients with rectal prolapse were categorized by surgical approach to repair (perineal or abdominal) and abdominal cases were further subdivided by procedure (resection compared with rectopexy alone). Univariate and multivariate analyses compared major and minor complication rates between the groups. RESULTS: Of 1275 patients, the perineal group (n=706, 55%) was older, with more comorbidity, than those undergoing an abdominal procedure. There were fewer minor (odd ratio (OR)=0.35; 95% confidence interval (CI), 0.20-0.60; P=0.0038) and major complications (OR=0.46; 95% CI, 0.31-0.80; P=0.0038) in the perineal compared with the abdominal cohort. There was a significant increase in major complications amongst patients undergoing a resection compared with rectopexy only (OR=2.15; 95% CI, 1.10-4.41; P=0.0299). There was no difference in major complications between abdominal rectopexy and a perineal approach, but the latter had a lower chance of minor complications (OR=0.47; 95% CI, 0.24-0.94; P=0.0287). CONCLUSION: A perineal approach is safer than an abdominal approach to the treatment of rectal prolapse. Regarding an abdominal operation, rectopexy has fewer major complications than resection.

Randomized controlled trial of patient-controlled sedation for colonoscopy: Entonox vs modified patient-maintained target-controlled propofol.

AIM: Propofol sedation is often associated with deep sedation and decreased manoeuvrability. Patient-maintained sedation has been used in such patients with minimal side-effects. We aimed to compare novel modified patient-maintained target-controlled infusion (TCI) of propofol with patient-controlled Entonox inhalation for colonoscopy in terms of analgesic efficacy (primary outcome), depth of sedation, manoeuvrability and patient and endoscopist satisfaction (secondary outcomes). METHOD: One hundred patients undergoing elective colonoscopy were randomized to receive either TCI propofol or Entonox. Patients in the propofol group were administered propofol initially to achieve a target concentration of 1.2 µg/ml and then allowed to self-administer a bolus of propofol (200 µg/kg/ml) using a patient-controlled analgesia pump with a handset. Entonox group patients inhaled the gas through a mouthpiece until caecum was reached and then as required. Sedation was initially given by an anaesthetist to achieve a score of 4 (Modified Observer's Assessment of Alertness and Sedation Scale), and colonoscopy was then started. Patients completed an anxiety score (Hospital Anxiety and Depression questionnaire), a baseline letter cancellation test and a pain score on a 100-mm visual analogue scale before and after the procedure. All patients completed a satisfaction survey at discharge and 24 h postprocedure. RESULTS: The median dose of propofol was 174 mg, and the median number of propofol boluses was four. There was no difference between the two groups in terms of pain recorded (95% confidence interval of the difference -0.809, 5.02) and patient/endoscopist satisfaction. There was no difference between the two groups in either depth of sedation or manoeuvrability. CONCLUSION: Both Entonox and the modified TCI propofol provide equally effective sedation and pain relief, simultaneously allowing patients to be easily manoeuvred during the procedures.

Differences in cytokine levels due to gender in colorectal cancer patients.

INTRODUCTION: Female gender is associated with longer survival after treatment for colorectal cancer (CRC). Reasons behind this phenomenon are not entirely clear. In addition, higher interleukin-6 (IL-6) and interleukin-1 (IL-1) levels have been found to be associated with poorer prognosis in CRC patients. The aim of this study was to investigate if cytokine levels were different in male and female CRC patients. METHODS: Pre- and post-operative levels of IL-1, interleukin-1 receptor antagonist (IL-1ra), IL-6 and tumour necrosis factor-alpha (TNF-alpha) were measured using standard solid phase sandwich ELISA in 104 consecutive eligible patients undergoing elective resection for CRC. RESULTS: Seventy (67.3%) participants were male and the mean age of the group was 67.6years (standard deviation 10.4years, range 39-86years). Pre-operative IL-1beta and post-operative IL-6 levels were significantly higher in males compared with females (U=486.5, p=0.03, U=424, p=0.04), values approaching statistical significance were obtained for pre-operative IL-6 (U=508.5, p=0.06) and post-operative IL-1beta (U=448, p=0.07). Differences in the levels of TNF-alpha and IL-1ra were not statistically significant. Multiple regression analysis using TNM stage as a covariate, showed that gender was an independent predictor of post-operative IL-6 levels (p=0.04). CONCLUSION: IL-1beta and IL-6 levels were significantly higher in men than in women. This provides evidence of a possible link between gender and cytokine levels in patients with colorectal cancer.

Quality assurance in flexible sigmoidoscopy: medical and nonmedical endoscopists.

PURPOSE: The clinical assessment of position in colon and hence completion during flexible sigmoidoscopy (FS) is believed to be inaccurate. The technique of applying endomucosal clips with follow-up X-ray has previously been used for establishing completion in colonoscopy. Furthermore, we have now trained non-healthcare professionals (non-medical endoscopists, NME) to perform FS, but there is no data on assessment of their performance of FS. We performed this study with the aims of determining accuracy of endoscopists' clinical impression regarding actual position of endoscope in colon during FS, comparing medical (ME) and NME in terms of clinical accuracy, and to determine role of endomucosal clips with follow-up X-rays in documenting completion and hence quality assurance. METHODS: All patients undergoing elective FS, except those with surgical resection, were included, after ethics approval. During FS, endoscopist applied an endomucosal clip at most proximal bowel reached and endoscopists recorded their independent opinion about position of clip. Post procedure, all patients underwent an abdominal X-ray, reported by consultant radiologist, blinded to outcome of FS. X-ray results were compared with endoscopist findings. Complete FS was defined as one where descending colon was reached. RESULTS: Fifty-one patients, with median age of 55 years, participated in study. The endoscopists were accurate in their assessment of position in colon in 38 patients (75%). The attending nurse was accurate in only 31% of cases. The crude and corrected completion rates were 73% and 84%, respectively. There was no correlation between length of endoscope and its position in colon. There were no differences between NME and ME in terms of clinical accuracy. CONCLUSION: This study has shown that clinical impression of endoscopist during FS regarding position is not very accurate, implying need for regular quality assurance. The technique of applying endomucosal clips with follow-on abdominal X-ray is an excellent objective measure of quality assurance in FS. NME can perform FS with comparable completion rates and accuracy.

Artificial neural networks to predict presence of significant pathology in patients presenting to routine colorectal clinics.

AIM: Artificial neural networks (ANNs) are computer programs used to identify complex relations within data. Routine predictions of presence of colorectal pathology based on population statistics have little meaning for individual patient. This results in large number of unnecessary lower gastrointestinal endoscopies (LGEs - colonoscopies and flexible sigmoidoscopies). We aimed to develop a neural network algorithm that can accurately predict presence of significant pathology in patients attending routine outpatient clinics for gastrointestinal symptoms. METHOD: Ethics approval was obtained and the study was monitored according to International Committee on Harmonisation - Good Clinical Practice (ICH-GCP) standards. Three-hundred patients undergoing LGE prospectively completed a specifically developed questionnaire, which included 40 variables based on clinical symptoms, signs, past- and family history. Complete data sets of 100 patients were used to train the ANN; the remaining data was used for internal validation. The primary output used was positive finding on LGE, including polyps, cancer, diverticular disease or colitis. For external validation, the ANN was applied to data from 50 patients in primary care and also compared with the predictions of four clinicians. RESULTS: Clear correlation between actual data value and ANN predictions were found (r = 0.931; P = 0.0001). The predictive accuracy of ANN was 95% in training group and 90% (95% CI 84-96) in the internal validation set and this was significantly higher than the clinical accuracy (75%). ANN also showed high accuracy in the external validation group (89%). CONCLUSION: Artificial neural networks offer the possibility of personal prediction of outcome for individual patients presenting in clinics with colorectal symptoms, making it possible to make more appropriate requests for lower gastrointestinal endoscopy.