Risk Factors for Readmission in Excisional Hemorrhoidectomy at a Tertiary Teaching Center.

INTRODUCTION: Unplanned readmission is often seen after excisional hemorrhoidectomy. This study aims to explore associations between patient and operative factors, and readmission rates in excisional hemorrhoidectomy. METHODS: We performed a retrospective analysis of all excisional hemorrhoidectomies performed in Capital and Coast District Health Board for an 8-year period from January 1, 2012, to December 31, 2020. The primary outcome measure was 30-day readmissions post hemorrhoidectomy. Univariate and multivariable logistic regression analyses were performed to identify risk factors to readmisson. A decision tree model was designed to further look at the interactions between risk factors. RESULTS: There were a total 370 patients undergoing 389 excisional hemorrhoidectomies over the study period. There were 47 (12.1%) readmissions. The commonest reasons for readmission were pain (48.9%) and bleeding (38%). 17% of readmitted patients required operative intervention. Readmission was associated with the use of advanced energy devices (OR 2.21; P = 0.027). Trainees were more likely to use advance energy devices than consultants (51% versus 38%, P = 0.010). Consultants were involved in more procedures requiring a removal of 3 pedicles or more than trainees (43% versus 30%, P = 0.010). A decision tree model predicts readmission based on primary operator experience, age, advanced energy device use, and patient ethnicity. CONCLUSIONS: Two risk models are presented showing the complex relationship between the factors associated with readmission after hemorrhoidectomy. Advanced energy device use was associated with an increased risk of readmission after hemorrhoidectomy in our population. Future work could involve targeted interventions to patients at increased risk of readmission such as preprocedural and postprocedural information, early interval follow-up and targeted analgesia regimes.

Delayed Gastric Emptying and Gastric Remnant Function After Pancreaticoduodenectomy: A Systematic Review of Objective Assessment Modalities.

BACKGROUND: Delayed gastric emptying (DGE) is a frequent complication after pancreaticoduodenectomy (PD). The diagnosis of DGE is based on International Study Group for Pancreatic Surgery (ISGPS) clinical criteria and objective assessments of DGE are infrequently used. The present literature review aimed to identify objective measures of DGE following PD and determine whether these measures correlate with the clinical definition of DGE. METHODS: A systematic search was performed using the MEDLINE Ovid, EMBASE, Google Scholar and CINAHL databases for studies including pancreatic surgery, delayed gastric emptying and gastric motility until June 2022. The primary outcome was modalities undertaken for the objective measurement of DGE following PD and correlation between objective measurements and clinical diagnosis of DGE. Relevant risk of bias analysis was performed. RESULTS: The search revealed 4881 records, of which 46 studies were included in the final analysis. There were four objective modalities of DGE assessment including gastric scintigraphy (n = 28), acetaminophen/paracetamol absorption test (n = 10), fluoroscopy (n = 6) and the 13C-acetate breath test (n = 3). Protocols were inconsistent, and reported correlations between clinical and objective measures of DGE were variable; however, amongst these measures, at least one study directly or indirectly inferred a correlation, with the greatest evidence accumulated for gastric scintigraphy. CONCLUSION: Several objective modalities to assess DGE following PD have been identified and evaluated, however are infrequently used. Substantial variability exists in the literature regarding indications and interpretation of these tests, and there is a need for a real-time objective modality which correlates with ISGPS DGE definition after PD.

Faecal incontinence is associated with an impaired rectosigmoid brake and improved by sacral neuromodulation.

BACKGROUND: The rectosigmoid brake, characterised by retrograde cyclic motor patterns on high-resolution colonic manometry, has been postulated as a contributor to the maintenance of bowel continence. Sacral neuromodulation (SNM) is an effective therapy for faecal incontinence, but its mechanism of action is unclear. This study aims to investigate the colonic motility patterns in the distal colon of patients with faecal incontinence, and how these are modulated by SNM. METHODS: A high-resolution fibreoptic colonic manometry catheter, containing 36 sensors spaced at 1-cm intervals, was positioned in patients with faecal incontinence undergoing stage 1 SNM. One hour of pre- and post meal recordings were obtained followed by pre- and post meal recordings with suprasensory SNM. A 700-kcal meal was given. Data were analysed to identify propagating contractions. RESULTS: Fifteen patients with faecal incontinence were analysed. Patients had an abnormal meal response (fewer retrograde propagating contractions compared to controls; p = 0.027) and failed to show a post meal increase in propagating contractions (mean 17 ± 6/h premeal vs. 22 ± 9/h post meal, p = 0.438). Compared to baseline, SNM significantly increased the number of retrograde propagating contractions in the distal colon (8 ± 3/h premeal vs. 14 ± 3/h premeal with SNM, p = 0.028). Consuming a meal did not further increase the number of propagating contractions beyond the baseline upregulating effect of SNM. CONCLUSION: The rectosigmoid brake was suppressed in this cohort of patients with faecal incontinence. SNM may exert a therapeutic effect by modulating this rectosigmoid brake.

Potential causes of the preoperative increase in the rectosigmoid cyclic motor pattern: A high-resolution manometry study.

BACKGROUND: Cyclic motor patterns (CMPs) are the most common motor pattern in the distal colon. This study used high-resolution (HR) colonic manometry to quantify trends in distal colonic motor activity before elective colonic surgery, determine the effect of a preoperative carbohydrate load, and compare this with a meal response in healthy controls. METHODS: Fiber-optic HR colonic manometry (36 sensors, 1 cm intervals) was used to investigate distal colonic motor activity in 10 adult patients prior to elective colonic surgery, 6 of whom consumed a preoperative carbohydrate drink (200 kCal). Data were compared with nine healthy volunteers who underwent HR colonic manometry recordings while fasted and following a 700 kCal meal. The primary outcome was the percentage of recording occupied by CMPs, defined as propagating contractions at 2-4 cycles per minute (cpm). Secondary outcomes included amplitude, speed, and distance of propagating motor patterns. RESULTS: The occurrence of CMPs progressively increased in time periods closer to surgery (p = 0.001). Consumption of a preoperative drink resulted in significantly increased CMP occurrence (p = 0.04) and propagating distance (p = 0.04). There were no changes in amplitude or speed of propagating motor patterns during the preoperative period. The increase in activity following a preoperative drink was of similar magnitude to the colonic meal response observed in healthy controls, despite the lesser caloric nutrient load. CONCLUSION: Distal colonic CMP increased in occurrence prior to surgery, amplified by ingestion of preoperative carbohydrate drinks. We hypothesize that anxiety, which is also known to rise with proximity to surgery, could play a contributing role.

Intraoperative serosal extracellular mapping of the human distal colon: a feasibility study.

BACKGROUND: Cyclic motor patterns (CMP) are the predominant motor pattern in the distal colon, and are important in both health and disease. Their origin, mechanism and relation to bioelectrical slow-waves remain incompletely understood. During abdominal surgery, an increase in the CMP occurs in the distal colon. This study aimed to evaluate the feasibility of detecting propagating slow waves and spike waves in the distal human colon through intraoperative, high-resolution (HR), serosal electrical mapping. METHODS: HR electrical recordings were obtained from the distal colon using validated flexible PCB arrays (6 × 16 electrodes; 4 mm inter-electrode spacing; 2.4 cm2, 0.3 mm diameter) for up to 15 min. Passive unipolar signals were obtained and analysed. RESULTS: Eleven patients (33-71 years; 6 females) undergoing colorectal surgery under general anaesthesia (4 with epidurals) were recruited. After artefact removal and comprehensive manual and automated analytics, events consistent with regular propagating activity between 2 and 6 cpm were not identified in any patient. Intermittent clusters of spike-like activities lasting 10-180 s with frequencies of each cluster ranging between 24 and 42 cpm, and an average amplitude of 0.54 ± 0.37 mV were recorded. CONCLUSIONS: Intraoperative colonic serosal mapping in humans is feasible, but unlike in the stomach and small bowel, revealed no regular propagating electrical activity. Although sporadic, synchronous spike-wave events were identifiable. Alternative techniques are required to characterise the mechanisms underlying the hyperactive CMP observed in the intra- and post-operative period. NEW FINDINGS: The aim of this study was to assess the feasibility of detecting propagating electrical activity that may correlate to the cyclic motor pattern in the distal human colon through intraoperative, high-resolution, serosal electrical mapping. High-resolution electrical mapping of the human colon revealed no regular propagating activity, but does reveal sporadic spike-wave events. These findings indicate that further research into appropriate techniques is required to identify the mechanism of hyperactive cyclic motor pattern observed in the intra- and post-operative period in humans.

ManoMap: an automated system for characterization of colonic propagating contractions recorded by high-resolution manometry.

RATIONALE: Colonic high-resolution manometry (cHRM) is an emerging clinical tool for defining colonic function in health and disease. Current analysis methods are conducted manually, thus being inefficient and open to interpretation bias. OBJECTIVE: The main objective of the study was to build an automated system to identify propagating contractions and compare the performance to manual marking analysis. METHODS: cHRM recordings were performed on 5 healthy subjects, 3 subjects with diarrhea-predominant irritable bowel syndrome, and 3 subjects with slow transit constipation. Two experts manually identified propagating contractions, from five randomly selected 10-min segments from each of the 11 subjects (72 channels per dataset, total duration 550 min). An automated signal processing and detection platform was developed to compare its effectiveness to manually identified propagating contractions. In the algorithm, individual pressure events over a threshold were identified and were then grouped into a propagating contraction. The detection platform allowed user-selectable thresholds, and a range of pressure thresholds was evaluated (2 to 20 mmHg). KEY RESULTS: The automated system was found to be reliable and accurate for analyzing cHRM with a threshold of 15 mmHg, resulting in a positive predictive value of 75%. For 5-h cHRM recordings, the automated method takes 22 ± 2 s for analysis, while manual identification would take many hours. CONCLUSIONS: An automated framework was developed to filter, detect, quantify, and visualize propagating contractions in cHRM recordings in an efficient manner that is reliable and consistent.

High-Resolution Colonic Manometry Pressure Profiles Are Similar in Asymptomatic Diverticulosis and Controls.

BACKGROUND: Elevated colonic pressures and increased colonic activity have been thought to contribute to the pathophysiology of diverticulosis. However, evidence for this has been limited to low-resolution manometry, which is of limited accuracy. AIMS: This study aimed to evaluate the contraction pressures, counts, and distance of propagation recorded by high-resolution colonic manometry in diverticulosis vs control patients. METHODS: High-resolution colonic manometry was used to record descending and sigmoid colon activity pre- and post-meal in patients with established, asymptomatic diverticulosis and in healthy controls. Antegrade and retrograde propagating contractions, distance of propagation (mm), and mean contraction pressures (mmHg) in the descending and sigmoid colon were compared between patients and controls for all isolated propagating contractions, the cyclic motor pattern, and high-amplitude propagating contractions independently. RESULTS: Mean manometry pressures were not different between controls and diverticulosis patients (p > 0.05 for all comparisons). In the descending colon, diverticulosis patients had lower post-meal mean distance of propagation for all propagating contractions [10.8 (SE1.5) mm vs 20.0 (2.0) mm, p = 0.003] and the cyclic motor pattern [6.0 (2.5) mm vs 17.1 (2.8) mm, p = 0.01]. In the sigmoid colon, diverticulosis patients showed lower post-meal mean distance of propagation for all propagating contractions [10.8 (1.5) mm vs 20.2 (5.9) mm, p = 0.01] and a lower post-meal increase in retrograde propagating contractions (p = 0.04). CONCLUSIONS: In this first high-resolution colonic manometry study of patients with diverticular disease, we did not find evidence for increased manometric pressures or increased colonic activity in patients with diverticular disease.

Development and feasibility of an ambulatory acquisition system for fiber-optic high-resolution colonic manometry.

BACKGROUND: High-resolution colonic manometry is an emerging technique that has provided new insights into the pathophysiology of functional colorectal diseases. Prior studies have been limited by bulky, non-ambulatory acquisition systems, which have prevented mobilization during prolonged recordings. METHODS: A novel ambulatory acquisition system for fiber-optic high-resolution colonic manometry was developed. Benchtop validation against a standard non-ambulatory system was performed using standardized calibration metrics. Clinical feasibility studies were conducted in three patients undergoing right hemicolectomy. RESULTS: Pressure profiles obtained from benchtop testing were near-identical using the ambulatory and the non-ambulatory systems. Clinical studies successfully demonstrated ambulatory data capture with patients freely mobilizing postoperatively during continuous recordings of >60 hours. The occurrence (P = .56), amplitude (P = .65), velocity (P = .10), and extent (P = .12) of colonic motor patterns were similar to those obtained in non-ambulatory studies. CONCLUSIONS: A novel ambulatory system for high-resolution colonic manometry has been developed and validated. This technique will facilitate prolonged ambulatory recordings of colonic motor activity, assisting with investigations into the role of colonic motility in disease states.

Can pathological reports of rectal cancer provide national quality indicators?

BACKGROUND: Rectal cancer care has become increasingly complex and requires accurate information. The pathology report is a vital tool for accessing information to gauge a patient's prognosis and to guide treatment decisions. The aim of this study was to assess the quality of histopathological reporting and surgery for rectal cancer in New Zealand using defined quality indicators. METHODS: This is a retrospective audit of pathological reports of all resected rectal cancer pathology reports submitted to the New Zealand Cancer Registry (NZCR) in 2015. The quality of reporting was assessed using specified criteria: synoptic report, adequate lymph node retrieval, reporting of circumferential resection margin (CRM) and mesorectal excision quality. Surgical outcomes were sphincter preservation rate, CRM clearance and complete mesorectal excision. RESULTS: A total of 803 patients with rectal cancer were reported to the NZCR in 2015, 505 underwent proctectomy. A total of 89.5% of reports were structured, 81.8% reported mesorectal excision quality and 86.7% reported CRM status. Adequate lymph node retrieval was obtained in 65.1%, complete mesorectal excision in 84.6% and positive CRM in 6.2% of cases. Quality varied between laboratories and district health boards. High-volume laboratories had higher quality reporting. Surgeon volume and training was related to adequate lymph node retrieval but not CRM clearance nor mesorectal excision quality. CONCLUSION: High-quality pathological reporting is associated with the use of synoptic reporting templates. Surgical outcomes for rectal cancer in New Zealand, especially the low rate of CRM involvement, compare favourably with international audits.

The "rectosigmoid brake": Review of an emerging neuromodulation target for colorectal functional disorders.

The regulation of gastrointestinal motility encompasses several overlapping mechanisms including highly regulated and coordinated neurohormonal circuits. Various feedback mechanisms or "brakes" have been proposed. While duodenal, jejunal, and ileal brakes are well described, a putative distal colonic brake is less well defined. Despite the high prevalence of colonic motility disorders, there is little knowledge of colonic motility owing to difficulties with organ access and technical difficulties in recording detailed motor patterns along its entire length. The motility of the colon is not under voluntary control. A wide range of motor patterns is seen, with long intervals of intestinal quiescence between them. In addition, the use of traditional manometric catheters to record contractile activity of the colon has been limited by the low number of widely spaced sensors, which has resulted in the misinterpretation of colonic motor patterns. The recent advent of high-resolution (HR) manometry is revolutionising the understanding of gastrointestinal motor patterns. It has now been observed that the most common motor patterns in the colon are repetitive two to six cycles per minute (cpm) propagating events in the distal colon. These motor patterns are prominent soon after a meal, originate most frequently in the rectosigmoid region, and travel in the retrograde direction. The distal prominence and the origin of these motor patterns raise the possibility of them serving as a braking mechanism, or the "rectosigmoid brake," to limit rectal filling. This review aims to describe what is known about the "rectosigmoid brake," including its physiological and clinical significance and potential therapeutic applications.

High-resolution anatomic correlation of cyclic motor patterns in the human colon: Evidence of a rectosigmoid brake.

Colonic cyclic motor patterns (CMPs) have been hypothesized to act as a brake to limit rectal filling. However, the spatiotemporal profile of CMPs, including anatomic origins and distributions, remains unclear. This study characterized colonic CMPs using high-resolution (HR) manometry (72 sensors, 1-cm resolution) and their relationship with proximal antegrade propagating events. Nine healthy volunteers were recruited. Recordings were performed over 4 h, with a 700-kcal meal given after 2 h. Propagating events were visually identified and analyzed by pattern, origin, amplitude, extent of propagation, velocity, and duration. Manometric data were normalized using anatomic landmarks identified on abdominal radiographs. These were mapped over a three-dimensional anatomic model. CMPs comprised a majority of detected propagating events. Most occurred postprandially and were retrograde propagating events (84.9 ± 26.0 retrograde vs. 14.3 ± 11.8 antegrade events/2 h, P = 0.004). The dominant sites of initiation for retrograde CMPs were in the rectosigmoid region, with patterns proximally propagating by a mean distance of 12.4 ± 0.3 cm. There were significant differences in the characteristics of CMPs depending on the direction of travel and site of initiation. Association analysis showed that proximal antegrade propagating events occurred independently of CMPs. This study accurately characterized CMPs with anatomic correlation. CMPs were unlikely to be triggered by proximal antegrade propagating events in our study context. However, the distal origin and prominence of retrograde CMPs could still act as a mechanism to limit rectal filling and support the theory of a "rectosigmoid brake."NEW & NOTEWORTHY Retrograde cyclic motor patterns (CMPs) are the dominant motor patterns in a healthy prepared human colon. The major sites of initiation are in the rectosigmoid region, with retrograde propagation, supporting the idea of a "rectosigmoid brake." A significant increase in the number of CMPs is seen after a meal. In our study context, the majority of CMPs occurred independent of proximal propagating events, suggesting that CMPs are primarily controlled by external innervation.

Dynamic Article: Full-Thickness Excision for Benign Colon Polyps Using Combined Endoscopic Laparoscopic Surgery.

BACKGROUND: Benign colon polyps are commonly encountered but may not always be amenable to endoscopic excision because of their size, shape, location, or scarring from previous attempts. The addition of laparoscopy allows a greater degree of bowel manipulation, but the current technique is still limited when encountering a polyp with inadequate lifting attributed to polyp morphology or scarring. We describe an extension to the existing combined endoscopic laparoscopic surgery technique using a full-thickness approach to increase polyp maneuverability and local excision of difficult but benign polyps. OBJECTIVE: The purpose of this study was to report the technical details and preliminary results of a new approach for full-thickness excision of difficult colon polyps, combined endoscopic laparoscopic surgery full-thickness excision. DESIGN: This study is a retrospective review of our experience from December 2013 to May 2015. SETTINGS: The study was conducted at a single academic institution. PATIENTS: All of the patients had previous incomplete colonoscopic polypectomy performed at other institutions. Patients were selected for our technique if the polyp had a benign appearance but was unable to be resected by traditional endoscopic or combined endoscopic laparoscopic surgery methods because of polyp morphology or scarring from previous biopsies. MAIN OUTCOME MEASURES: The safety and feasibility of this procedure were measured. RESULTS: Three patients underwent combined endoscopic laparoscopic surgery-full-thickness excision for difficult colon polyps. There were no intraoperative or postoperative complications. The length of stay was 1 day for all of the patients. All 3 of the patients had benign final pathology. LIMITATIONS: This study was limited by the small number of patients in a single institution. CONCLUSIONS: Full-thickness excision for benign colon polyps using combined endoscopic laparoscopic surgery is safe and feasible. Using this technique, difficult polyps not amenable to traditional endoscopic approaches can be removed and colectomy may be avoided.

Risk stratification of patients undergoing pulmonary metastasectomy for soft tissue and bone sarcomas.

OBJECTIVES: Our objective was to identify risk factors associated with survival in patients who underwent pulmonary metastasectomy for soft tissue or bone sarcoma and to create a risk stratification model. METHODS: A retrospective review of the prospectively maintained University of California Los Angeles Sarcoma Database was performed. Clinical, pathologic, and treatment variables were analyzed for overall survival and disease-free survival. Univariate and multivariate analyses were performed, and variables that were identified as significant were included to create a risk model. A total of 155 patients who underwent pulmonary metastasectomy for soft tissue sarcoma (n = 108 patients) or bone sarcoma (n = 47 patients) from 1994 to 2010 were identified. RESULTS: Multivariate analysis identified 7 factors associated with poor overall survival: age more than 45 years, disease-free interval less than 1 year, thoracotomy, synchronous disease, location and type of sarcoma (soft tissue vs bone sarcoma), and performance of a lobectomy. The number of factors present was associated with poor overall survival, which varied widely from 64% in patients with 2 factors to 3% in those with 5 factors. CONCLUSIONS: We have identified prognostic variables associated with overall survival after lung metastasectomy. Our model may be used as a risk stratification model to guide treatment decisions on the basis of the number of risk factors present. Although prospective studies are warranted to determine the benefit of surgical intervention in all cohorts compared with other local therapies or medical therapy, given the attendant dismal prognosis in patients with 5 or more risk factors, the benefit of surgical resection in this group is questioned.