Report of the Association of Coloproctology of Great Britain and Ireland/British Society of Gastroenterology Colorectal Polyp Working Group: the development of a complex colorectal polyp minimum dataset.

AIM: The management of large non-pedunculated colorectal polyps (LNPCPs) is complex, with widespread variation in management and outcome, even amongst experienced clinicians. Variations in the assessment and decision-making processes are likely to be a major factor in this variability. The creation of a standardized minimum dataset to aid decision-making may therefore result in improved clinical management. METHOD: An official working group of 13 multidisciplinary specialists was appointed by the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and the British Society of Gastroenterology (BSG) to develop a minimum dataset on LNPCPs. The literature review used to structure the ACPGBI/BSG guidelines for the management of LNPCPs was used by a steering subcommittee to identify various parameters pertaining to the decision-making processes in the assessment and management of LNPCPs. A modified Delphi consensus process was then used for voting on proposed parameters over multiple voting rounds with at least 80% agreement defined as consensus. The minimum dataset was used in a pilot process to ensure rigidity and usability. RESULTS: A 23-parameter minimum dataset with parameters relating to patient and lesion factors, including six parameters relating to image retrieval, was formulated over four rounds of voting with two pilot processes to test rigidity and usability. CONCLUSION: This paper describes the development of the first reported evidence-based and expert consensus minimum dataset for the management of LNPCPs. It is anticipated that this dataset will allow comprehensive and standardized lesion assessment to improve decision-making in the assessment and management of LNPCPs.

The use of an acellular porcine dermal collagen implant in the repair of complex abdominal wall defects: a European multicentre retrospective study.

BACKGROUND: The use of biological materials for the repair of complex abdominal wall defects has increased over the years; however, the role of these materials in routine practice remains unclear. The aim of the study was to evaluate clinical outcomes following the use of Permacol™ porcine collagen surgical implant in complex abdominal wall repair. METHODS: This subset analysis of seven European sites from a multicentre retrospective study included patients undergoing open or laparoscopic surgery and treated with Permacol™ surgical implant. Inguinal, parastomal, diaphragmatic, perineal, and hiatal repairs were excluded. Only patients with at least 12 months of follow-up after surgery were included. RESULTS: A total of 109 patients (56 males and 53 females) were included. Patients had a median of two comorbidities (range 0-6). Thirty-three per cent of patients were treated for recurrent hernia. All but one case used an open approach. Sixty-six per cent were Center for Disease Control wound class II-IV at the time of surgery. Fascial closure was achieved in 69%. Median follow-up length was 720 days (range 368-2857). Recurrence rates at 1 and 2 years were 9.2 and 18.3 %, respectively, and were higher in cases without fascial closure. One-year recurrence was higher following use of an onlay technique (P = 0.025). In a multivariate analysis, among 16 comorbidities examined only fascial closure significantly impacted 1-year recurrence (P = 0.049). CONCLUSIONS: Data from this large retrospective multicentre European study strongly suggest the use of Permacol™ porcine collagen surgical implant to be safe and effective for complex abdominal wall repair. The recurrence rate was impacted by fascial closure.

Modelling and predicting the spatio-temporal spread of COVID-19, associated deaths and impact of key risk factors in England.

COVID-19 caseloads in England have passed through a first peak, and at the time of this analysis appeared to be gradually increasing, potentially signalling the emergence of a second wave. To ensure continued response to the epidemic is most effective, it is imperative to better understand both retrospectively and prospectively the geographical evolution of COVID-19 caseloads and deaths at small-area resolution, identify localised areas in space-time at significantly higher risk, quantify the impact of changes in localised population mobility (or movement) on caseloads, identify localised risk factors for increased mortality and project the likely course of the epidemic at high spatial resolution in coming weeks. We applied a Bayesian hierarchical space-time SEIR model to assess the spatiotemporal variability of COVID-19 caseloads (transmission) and deaths at small-area scale in England [Middle Layer Super Output Area (MSOA), 6791 units] and by week (using observed data from week 5 to 34 of 2020), including key determinants, the modelled transmission dynamics and spatial-temporal random effects. We also estimate the number of cases and deaths at small-area resolution with uncertainty projected forward in time by MSOA (up to week 51 of 2020), the impact mobility reductions (and subsequent easing) have had on COVID-19 caseloads and quantify the impact of key socio-demographic risk factors on COVID-19 related mortality risk by MSOA. Reductions in population mobility during the course of the first lockdown had a significant impact on the reduction of COVID-19 caseloads across England, however local authorities have had a varied rate of reduction in population movement which our model suggest has substantially impacted the geographic heterogeneity in caseloads at small-area scale. The steady gain in population mobility, observed from late April, appears to have contributed to a slowdown in caseload reductions towards late June and subsequent start of the second wave. MSOA with higher proportions of elderly (70+ years of age) and elderly living in deprivation, both with very distinct geographic distributions, have a significantly elevated COVID-19 mortality rates. While non-pharmaceutical interventions (that is, reductions in population mobility and social distancing) had a profound impact on the trajectory of the first wave of the COVID-19 outbreak in England, increased population mobility appears to have significantly contributed to the second wave. A number of contiguous small-areas appear to be at a significant elevated risk of high COVID-19 transmission, many of which are also at increased risk for higher mortality rates. A geographically staggered re-introduction of intensified social distancing measures is advised and limited cross MSOA movement if the magnitude and geographic extent of the second wave is to be reduced.

The health impact of polyparasitism in humans: are we under-estimating the burden of parasitic diseases?

Parasitic infections are widespread throughout the tropics and sub-tropics, and infection with multiple parasite species is the norm rather than the exception. Despite the ubiquity of polyparasitism, its public health significance has been inadequately studied. Here we review available studies investigating the nutritional and pathological consequences of multiple infections with Plasmodium and helminth infection and, in doing so, encourage a reassessment of the disease burden caused by polyparasitism. The available evidence is conspicuously sparse but is suggestive that multiple human parasite species may have an additive and/or multiplicative impact on nutrition and organ pathology. Existing studies suffer from a number of methodological limitations and adequately designed studies are clearly necessary. Current methods of estimating the potential global morbidity due to parasitic diseases underestimate the health impact of polyparasitism, and possible reasons for this are presented. As international strategies to control multiple parasite species are rolled-out, there is a number of options to investigate the complexity of polyparasitism, and it is hoped that that the parasitological research community will grasp the opportunity to understand better the health of polyparasitism in humans.

Associations between school- and household-level water, sanitation and hygiene conditions and soil-transmitted helminth infection among Kenyan school children.

BACKGROUND: Soil-transmitted helminths, a class of parasitic intestinal worms, are pervasive in many low-income settings. Infection among children can lead to poor nutritional outcomes, anaemia, and reduced cognition. Mass treatment, typically administered through schools, with yearly or biannual drugs is inexpensive and can reduce worm burden, but reinfection can occur rapidly. Access to and use of sanitation facilities and proper hygiene can reduce infection, but rigorous data are scarce. Among school-age children, infection can occur at home or at school, but little is known about the relative importance of WASH in transmission in these two settings. METHODS: We explored the relationships between school and household water, sanitation, and hygiene conditions and behaviours during the baseline of a large-scale mass drug administration programme in Kenya. We assessed several WASH measures to quantify the exposure of school children, and developed theory and empirically-based parsimonious models. RESULTS: Results suggest mixed impacts of household and school WASH on prevalence and intensity of infection. WASH risk factors differed across individual worm species, which is expected given the different mechanisms of infection. CONCLUSIONS: No trend of the relative importance of school versus household-level WASH emerged, though some factors, like water supply were more strongly related to lower infection, which suggests it is important in supporting other school practices, such as hand-washing and keeping school toilets clean.

Effect of nicotine on large bowel mucus thickness, eicosanoids and faecal proteinase in ferrets.

BACKGROUND: Following observations on the effect of subcutaneous nicotine on rectal mucosal eicosanoids and mucus in the rabbit we have repeated the work in ferrets which may be a more suitable animal model. AIMS AND METHODS: The effect of nicotine on mucosal eicosanoids, the adherent mucus layer, and faecal proteinases in the large bowel of ferrets was examined in forty animals randomly allocated to five groups, a control and four treatment groups. They were given subcutaneous saline or nicotine via an Alzet pump in doses of 0.3, 0.6, 1.2 and 2.0 mg/kg/day for 10 days and then sacrificed; measurements were made of serum nicotine and cotinine levels, rectal mucosal eicosanoids, adherent rectal and colonic mucus thickness, and faecal proteinases. RESULTS: No significant differences were observed for any measurements, except for serum nicotine and cotinine levels, which were raised consistent with the dose given. CONCLUSION: Nicotine had no effect on measurements, which may possibly be important in the relationship between smoking and ulcerative colitis.

Colonic mucus, smoking and ulcerative colitis.

Human colonic mucosal protection is not fully understood but may in part rely on a layer of mucus gel adherent to the mucosa. Ulcerative colitis may occur if mucosal protection breaks down. Two studies are presented, both of which relate to the aetiology of ulcerative colitis. First, a layer of adherent mucus gel was demonstrated by a simple, reliable method. Measurements of mucus layer thickness were made in freshly resected colonic specimens and shown to increase from a mean of 107 microns on the right colon to 155 microns in the rectum. In ulcerative colitis the layer is significantly thinner or absent, whereas in Crohn's disease the colonic mucus layer is significantly thicker. Second, the relationship between smoking and colitis is explored by a double-blind, randomised and placebo-controlled trial of transdermal nicotine in active disease. Significant clinical benefit was seen, indicating nicotine may be both useful therapeutically and the component of tobacco smoke that acts to protect against colitis. Since smoking and nicotine have actions on mucosae and mucus in other organs, it is argued that there is a mucus deficiency in ulcerative colitis that smoking acts to reverse.

Is an outpatient appointment required for patients referred for a minor operation under local anaesthetic?

The necessity of an outpatient (OP) consultation for patients referred for minor surgery under local anaesthetic (LA) was examined. Two separate prospective studies were performed. The first comprised 107 patients referred for minor surgery, who were assessed in the outpatient department (OPD), before being booked for minor operations. The second study comprised 106 patients whose names were placed directly on a minor operations list on the basis of the GP referral letter alone. In the first study, 97 (91 per cent) patients went on to undergo minor surgery. Five were not suitable for LA and in five an operation was considered unnecessary. Patients not suitable for LA included children, neck swellings, pre-auricular swellings and swellings described as lymph nodes. In the second study, the GP referral letters were screened to exclude the above and of 106 referrals 93 (88 per cent) underwent a minor operation. The benefit of the second study was twofold. First, 106 OP slots were available for other referrals and secondly, patients avoided the OP waiting list and did not lose time from work as a result of the OP visit. There were no adverse effects demonstrated during the second study. We believe the OP consultation can be avoided if the referral letters are carefully screened.

A novel method for determining the difficulty of colonoscopic polypectomy.

INTRODUCTION: Endoscopists are now expected to perform polypectomy routinely. Colonic polypectomy varies in difficulty, depending on polyp morphology, size, location and access. The measurement of the degree of difficulty of polypectomy, based on polyp characteristics, has not previously been described. OBJECTIVE: To define the level of difficulty of polypectomy. METHODS: Consensus by nine endoscopists regarding parameters that determine the complexity of a polyp was achieved through the Delphi method. The endoscopists then assigned a polyp complexity level to each possible combination of parameters. A scoring system to measure the difficulty level of a polyp was developed and validated by two different expert endoscopists. RESULTS: Through two Delphi rounds, four factors for determining the complexity of a polypectomy were identified: size (S), morphology (M), site (S) and access (A). A scoring system was established, based on size (1-9 points), morphology (1-3 points), site (1-2 points) and access (1-3 points). Four polyp levels (with increasing level of complexity) were identified based on the range of scores obtained: level I (4-5), level II (6-9), level III (10-12) and level IV (>12). There was a high degree of interrater reliability for the polyp scores (interclass correlation coefficient of 0.93) and levels (κ=0.888). CONCLUSIONS: The scoring system is feasible and reliable. Defining polyp complexity levels may be useful for planning training, competency assessment and certification in colonoscopic polypectomy. This may allow for more efficient service delivery and referral pathways.

Thickness of adherent mucus gel on colonic mucosa in humans and its relevance to colitis.

The thickness of adherent mucus gel on the surface of colonic mucosa was measured in surgically resected specimens from 46 'control' patients most of whom had carcinoma of the colon; 12 were from right colon, 17 left colon, and 21 from rectum. In addition specimens were examined from 17 patients with ulcerative colitis and 15 patients with Crohn's disease. In controls a continuous layer of mucus was readily seen on specially prepared sections viewed by phase contrast illumination. Mean values for right and left colon and rectum were 107 (48), 134 (68), and 155 (54) microns respectively with a significant difference between right colon and rectum (p = 0.015). Values in ulcerative colitis showed greater variation and in those areas with acute inflammation mucosa was denuded of the mucus layer. In contrast, values for Crohn's disease were normal or greater than normal in thickness--right colon 190 (83) microns compared with 107 48 microns, p = 0.0093. A series of validation experiments are described for the method used to measure mucus thickness. The possible role of mucus in the pathogenesis of inflammatory bowel disease is discussed.

Malignant pancreatic polypeptide secreting tumour of islet cells: a case for aggressive surgical palliation.

A case of a malignant pancreatic polypeptide secreting tumour is reported. The tumour was metastatic at presentation at which time it was excised. Pancreatic duct obstruction occurred 3 years after excision causing severe pain on eating. Major palliative surgery, in the form of a pancreatico-jejunostomy, cured the severe symptoms. The patient survives, largely symptom free, over six years after original excision. This case illustrates the need for aggressive management of symptoms in tumours in which long term survival is possible despite locally advanced or metastatic disease.

Comparison of bismuth citrate and 5-aminosalicylic acid enemas in distal ulcerative colitis: a controlled trial.

An enema that contained a complex of bismuth citrate and polyacrylate was compared with 5-aminosalicylic acid (5-ASA) enemas for treatment of distal ulcerative colitis. The multicentre trial involving 63 patients was randomised and double blind with enemas given over four weeks; clinical, sigmoidoscopic, and histological assessments were made. Improvements were seen in both treatment groups. Clinical remission was seen in 18 of 32 patients treated with 5-ASA and 12 of 31 patients treated with bismuth citrate-carbomer (chi 2 1.94; p = 0.16). Sigmoidoscopic remission occurred in 20 of 32 patients in the 5-ASA group and 15 of 31 patients given bismuth (chi 2 1.27; p = 0.26). Improvement of rectal biopsy histology by at least one grade was seen in 16 of 32 patients in the 5-ASA group and 14 of 31 patients with bismuth (chi 2 0.15; p = 0.70). Analysis of covariance gave no significant difference between groups, although there was a trend favouring 5-ASA. There was no evidence of bismuth accumulation during the trial. Bismuth enemas may offer a new therapeutic option in distal ulcerative colitis.

Controlled trial of anti-tuberculous chemotherapy for two years in Crohn's disease.

One hundred and thirty patients with active symptoms of Crohn's disease were treated in a double blind randomised controlled trial with rifampicin, isoniazid, and ethambutol, or identical placebos for up to two years. All other treatment considered necessary was continued. Analyses were based on 126 patients, 63 in each treatment group. Thirty seven in the active and 30 in the placebo group had previous surgical procedures. There was no difference in concomitant treatment between the two groups. Thirty in the active and 46 in the placebo groups were taking corticosteroids at entry to the trial. Forty eight of 63 patients in the active and 49 of 63 in the placebo group, completed at least 12 months' therapy. Reasons for early withdrawal included pregnancy, adverse reaction, and failure to comply. There was no significant difference in the mean number of months completed between the two groups. Nineteen adverse reactions were recorded for 17 patients in the active group compared with three reactions in patients on placebo. All of the nine patients withdrawn early because of adverse reactions were in the active group. Fifteen patients on active treatment and 14 on placebo had surgery during the trial with no difference in the type of surgery required between the groups. Radiological assessments based on 98 patients at the end of the trial showed no significant differences between groups in changes of extent of disease. More patients developed strictures on placebo compared with active treatment but without a statistically significant difference. No differences were found between groups for the total prednisolone dose or the number of days on which prednisolone dose was 10 mg or above. Serial measurements of body weight and Crohn's disease activity index (CDAI) together with blood values for albumin, haemoglobin, white cell count, and platelets showed no consistent different differences between groups. There were occasional significant differences for some of these values between groups, which were not sustained. The trail provides little evidence of tangible benefit from the trail treatment.

Transdermal nicotine for active ulcerative colitis.

BACKGROUND: Ulcerative colitis is largely a disease of nonsmokers. Because anecdotal reports suggest that smoking and nicotine may improve the symptoms of the disease, we examined the effect of nicotine as a supplemental treatment for ulcerative colitis. METHODS: We treated 72 patients with active ulcerative colitis with either transdermal nicotine patches or placebo patches for six weeks in a randomized, double-blind study. Incremental doses of nicotine were given; most patients tolerated doses of 15 to 25 mg per 24 hours. All the patients had been taking mesalamine, and 12 were receiving low doses of glucocorticoids; these medications were continued without change during the study. Clinical, sigmoidoscopic, and histologic assessments were made at base line and at the end of the study; symptoms were recorded daily on a diary card, and the clinician made a global assessment. Side effects and plasma nicotine and cotinine concentrations were monitored throughout the study. RESULTS: Seventeen of the 35 patients in the nicotine group had complete remissions, as compared with 9 of the 37 patients in the placebo group (P = 0.03). The patients in the nicotine group had greater improvement in the global clinical grade of colitis (P < 0.001) and the histologic grade (P = 0.03), lower stool frequency (a difference of 1.6 stools daily; P = 0.008), less abdominal pain (P = 0.05), and less fecal urgency (P = 0.009). More patients in the nicotine group had side effects (23, vs. 11 in the placebo group; P = 0.002), the most common of which were nausea, lightheadedness, headache, and sleep disturbance. Withdrawals due to ineffective therapy were more common in the placebo group (3 vs. 8, P = 0.12). CONCLUSIONS: The addition of transdermal nicotine to conventional maintenance therapy improves symptoms in patients with ulcerative colitis.