Faculty Bibliography

Elective colorectal surgery is associated with one of the highest rates of surgical site infections (SSIs), which result in prolonged length of stay, morbidity, and mortality for these patients and have a significant financial burden to healthcare systems. In an effort to reduce the frequency of SSI rates associated with colorectal surgery, the 2018 World Health Organisation (WHO) guidelines recommend the routine use of mechanical bowel preparation (MBP) and oral antibiotic prophylaxis (OAP) in adult patients undergoing elective colorectal surgery. However, this recommendation remains a topic of debate internationally. The National Institute of Clinical Excellence (NICE) guidelines, last revised in 2019, recommend against the routine use of MBP and do not address the issue of OAP. In this communication, we reviewed the current guidelines and examined the most recent evidence from randomised-control trials (RCTs) and meta-analyses on the effect of MBP and OAP on SSI rates since the 2019 NICE guideline review. This recent evidence clearly demonstrated an SSI-risk-reduction benefit with the additional use of OAP and the combination of MBP and OAP in this group of patients, and we therefore highlight the need for change of the current NICE guidelines.

BACKGROUND:Major burns complicated by stress ulceration and perforation of the stomach or duodenum is a recognized clinical phenomenon. Colonic perforation in burns patients is not common, and the overall incidence, diagnosis, intervention undertaken and mortality is incompletely described in the literature. METHOD:We performed a systematic review of the literature on severe burns resulting in colonic perforation during the initial admission period. Relevant studies from January 1975 to June 2020 were retrieved from MEDLINE and EMBASE databases. Patient demographics, co-morbidities, total body surface area (TBSA) and anatomical region of burn, site of colonic perforation and management, nutrition, sepsis and microbiology, length of stay and overall outcome were extracted. We present a case series of five burns patients who had colonic perforations in our Specialist Burns Center. RESULTS:We identified 54 studies, of which nine (two case series and seven case reports) met the inclusion criteria. Colonic perforation following burns was most common in middle-aged male patients with a proportion of patients having a history of mental health issues. In most cases, the TBSA associated with a colonic perforation was ≥30% (11/16 patients, 69%). Perforations mainly affected the right side of the colon (12/16 patients, 75%), usually occurring after the second week of admission (13/16 patients, 81%). Right-sided colonic perforations were associated with an increased mortality rate compared to left-sided perforations (42% vs 25%). CONCLUSIONS:The current literature is mainly limited to case series and case reports and confirms that colonic perforations in burns patients are rare. Colonic perforations are related to the systemic effect of burn injuries including sepsis and gastrointestinal stasis. We have identified patients who are at higher risk of developing colonic perforations and have described the common findings in these patients. Through greater awareness early diagnosis and prompt intervention may be achieved to improve outcomes and reduce associated morbidity and mortality.

PURPOSE/OBJECTIVE:To assess the efficacy and safety of a catheter-directed hemorrhoidal dearterialization technique for the management of hemorrhoidal bleeding. MATERIALS AND METHODS/METHODS:A systematic review and meta-analysis of pubmed, cochrane, and scopus databases was conducted according to the preferred reporting items for systematic reviews and meta-Analysis (PRISMA) guidelines. Clinical studies reporting on catheter-directed hemorrhoidal dearterialization for rectal bleeding were analyzed. RESULTS:Fourteen studies (n = 362) were identified. The mean maximum follow-up duration was 12.1 months (SD, 7.31; range, 1-28; median, 12), and the mean length of hospital stay was 1.5 days (SD, 1.1; range, 0-2.5). The mean technical success was 97.8% (SD, 3.5), and the mean clinical success was 78.9% (SD, 10.5). A statistically significant reduction in the french bleeding score before and after embolization was noted (P = .004). In subgroup analysis, when the coils-only group was compared with the coils and particles group, the average rebleeding rate was 21.5% (n = 111; SD, 18.2; range, 0%-44%) versus 10.05% (N = 108; SD, 4.8; range, 5%-15.7%), respectively (P < .0001). No bowel ischemia/necrosis or anorectal complications were reported. CONCLUSIONS:The current preliminary clinical evidence suggests that catheter-directed hemorrhoidal dearterialization is an effective and safe procedure for the treatment of hemorrhoidal bleeding. The standardization of the technique and the generation of higher level evidence will be required to compare this minimally invasive procedure with more invasive surgical options for patients with grades I-III hemorrhoids and chronic bleeding.

BACKGROUND:Classification of pelvic local recurrence (LR) after surgery for primary rectal cancer is not currently standardized and optimal imaging is required to categorize anatomical site and plan treatment in patients with LR. The aim of this review was to evaluate the systems used to classify locally recurrent rectal cancer (LRRC) and the relevant published outcomes. METHODS:A systematic review of the literature prior to April 2020 was performed through electronic searches of the Science Citation Index Expanded, EMBASE, MEDLINE and CENTRAL databases. The primary outcome was to review the classifications currently in use; the secondary outcome was the extraction of relevant information provided by these classification systems including prognosis, anatomy and prediction of R0 after surgery. RESULTS:A total of 21 out of 58 eligible studies, classifying LR in 2086 patients, were reviewed. Studies used at least one of the following eight classification systems proposed by institutions or institutional groups (Mayo Clinic, Memorial Sloan-Kettering - original and modified, Royal Marsden and Leeds) or authors (Yamada, Hruby and Kusters). Negative survival outcomes were associated with increased pelvic fixity, associated symptoms of LR, lateral compared with central LR and involvement of three or more pelvic compartments. A total of seven studies used MRI with specifically defined anatomical compartments to classify LR. CONCLUSION:This review highlights the various imaging systems in use to classify LRRC and some of the prognostic indicators for survival and oncological clearance based on these systems. Implementation of an agreed classification system to document pelvic LR consistently should provide more detailed information on anatomical site of recurrence, burden of disease and standards for comparative outcome assessment.

The perioperative care of colorectal cancer (CRC) patients includes antibiotics. Although antibiotics do provide a certain protection against infections, they do not eliminate them completely, and they do carry risks of microbial resistance and disruption of the microbiome. Probiotics can maintain the microbiome's balance postoperatively by maintaining intestinal mucosal integrity and reducing bacterial translocation (BT). This review aims to assess the role of probiotics in the perioperative management of CRC patients. The outcomes were categorised into: postoperative infectious and non-infectious complications, BT rate analysis, and intestinal permeability assessment. Fifteen randomised controlled trials (RCTs) were included. There was a trend towards lower rates of postoperative infectious and non-infectious complications with probiotics versus placebo. Probiotics reduced BT, maintained intestinal mucosal permeability, and provided a better balance of beneficial to pathogenic microorganisms. Heterogeneity among RCTs was high. Factors that influence the effect of probiotics include the species used, using a combination vs. single species, the duration of administration, and the location of the bowel resection. Although this review provided evidence for how probiotics possibly operate and reported notable evidence that probiotics can lower rates of infections, heterogeneity was observed. In order to corroborate the findings, future RCTs should keep the aforementioned factors constant.

Pelvic exenteration surgery for locally advanced rectal cancers is a complex and extensive multivisceral operation, which is associated with high perioperative morbidity and mortality rates. Significant technical challenges may arise due to inadequate access, visualisation, and characterisation of tissue planes and critical structures in the spatially constrained pelvis. Over the last two decades, robotic-assisted technologies have facilitated substantial advancements in the minimally invasive approach to total mesorectal excision (TME) for rectal cancers. Here, we review the emerging experience and evidence of robotic assistance in beyond TME multivisceral pelvic exenteration for locally advanced rectal cancers where heightened operative challenges and cumbersome ergonomics are likely to be encountered.

To advance the field of soft robotics, a unified database of material constitutive models and experimental characterizations is of paramount importance. This will facilitate the use of finite element analysis to simulate their behavior and optimize the design of soft-bodied robots. Samples from seventeen elastomers, namely Body Double™ SILK, Dragon Skin™ 10 MEDIUM, Dragon Skin 20, Dragon Skin 30, Dragon Skin FX-Pro, Dragon Skin FX-Pro + Slacker, Ecoflex™ 00-10, Ecoflex 00-30, Ecoflex 00-50, Rebound™ 25, Mold Star™ 16 FAST, Mold Star 20T, SORTA-Clear™ 40, RTV615, PlatSil^® Gel-10, Psycho Paint^®, and SOLOPLAST 150318, were subjected to uniaxial tensile tests according to the ASTM D412 standard. Sample preparation and tensile test parameters are described in detail. The tensile test data are used to derive parameters for hyperelastic material models using nonlinear least-squares methods, which are provided to the reader. This article presents the mechanical characterization and the resulting material properties for a wide set of commercially available hyperelastic materials, many of which are recognized and commonly applied in the field of soft robotics, together with some that have never been characterized. The experimental raw data and the algorithms used to determine material parameters are shared on the Soft Robotics Materials Database GitHub repository to enable accessibility, as well as future contributions from the soft robotics community. The presented database is aimed at aiding soft roboticists in designing and modeling soft robots while providing a starting point for future material characterizations related to soft robotics research.

BACKGROUND:Histological subtypes of colorectal cancer may be associated with varied prognostic features. This systematic review and meta-analysis aimed to compare clinicopathological characteristics, recurrence and overall survival between colorectal signet-ring cell (SC) and mucinous carcinoma (MC) to conventional adenocarcinoma (AC). METHODS:A literature search of MEDLINE, EMBASE, Ovid and Cochrane Library was performed for studies that reported data on clinicopathological and survival outcomes on SC and/or MC versus AC from January 1985 to May 2020. Meta-analysis was performed using random-effect models and between-study heterogeneity was assessed. RESULTS:98.6%; p < 0.001, respectively). CONCLUSION/CONCLUSIONS:SC and MC are associated with right-sided lesions, advanced stage at presentation, higher rates of recurrence and poorer overall survival. This has strong implications towards surgical and oncological management and surveillance of colorectal cancer.

BACKGROUND:Colorectal surgery is associated with significant pain often requiring opioid and non-opioid analgesics. Pudendal nerve blocks (PNBs) can be administered with the aim to reduce pain and improve patient satisfaction. However, there are no current accepted guidelines for the use of PNB in colorectal surgery. METHOD/METHODS:We evaluated the available literature on the role of PNB in colorectal surgery to determine which technique and anesthetic agent may provide optimal pain relief and safety. Studies from January 1970 to December 2019 assessing PNB in colorectal surgery were retrieved from MEDLINE and EMBASE databases. Indication for PNB, technique, anesthetic agent, postoperative pain outcomes, patient satisfaction and complications were extracted. RESULTS:We initially identified 339 studies of which 17 (nine randomized controlled trials, three cohort studies, one case-control study and four reviews) specifically met the inclusion criteria. The most common indication found for PNB is hemorrhoidectomy using either bupivacaine or lidocaine. The anatomical landmark and neurostimulation are the most favorable techniques being applied. The majority of studies reported better pain scores, less analgesia requirement and higher patient satisfaction when performing a bilateral PNB, with no major complications. CONCLUSIONS:The current evidence, though limited, supports the use of bilateral PNBs in colorectal surgical procedures in particular hemorrhoidectomies. PNBs can be safe and effective in improving patient outcomes particularly when using bupivacaine or lidocaine with either the anatomical landmark or neurostimulation technique.

INTRODUCTION:Abdominal wall herniation (AWH) is an increasing problem for patients, surgeons, and healthcare providers. Surgical-site specific outcomes, such as infection, recurrence, and mesh explantation, are improving; however, successful repair still exposes the patient to what is often a complex major operation aimed at improving quality of life. Quality-of-life (QOL) outcomes, such as aesthetics, pain, and physical and emotional functioning, are less often and less well reported. We reviewed QOL tools currently available to evaluate their suitability. METHODS:A systematic review of the literature in compliance with PRISMA guidelines was performed between 1st January 1990 and 1st May 2019. English language studies using validated quality-of-life assessment tool, whereby outcomes using this tool could be assessed were included. RESULTS:Heterogeneity in the QOL tool used for reporting outcome was evident throughout the articles reviewed. AWH disease-specific tools, hernia-specific tools, and generic tools were used throughout the literature with no obviously preferred or dominant method identified. CONCLUSION:Despite increasing acknowledgement of the need to evaluate QOL in patients with AWH, no tool has become dominant in this field. Assessment, therefore, of the impact of certain interventions or techniques on quality of life remains difficult and will continue to do so until an adequate standardised outcome measurement tool is available.