Randomized clinical trial of biodegradeable intraluminal sheath to prevent anastomotic leak after stapled colorectal anastomosis

Poly-ϵ-caprolactone scaffold as staple-line reinforcement of rectal anastomosis: an experimental piglet study

PURPOSE

Rectal anastomoses have a persisting high incidence of anastomotic leakage. This study aimed to assess whether the use of a poly-ϵ-caprolactone (PCL) scaffold as reinforcement of a circular stapled rectal anastomosis could increase tensile strength and improve healing compared to a control in a piglet model.

METHOD

Twenty weaned female piglets received a stapled rectal anastomosis and were randomised to either reinforcement with PCL scaffold (intervention) or no reinforcement (control). On postoperative day five the anastomosis was subjected to a tensile strength test followed by a histological examination to evaluate the wound healing according to the Verhofstad scoring.

RESULTS

The tensile strength test showed no significant difference between the two groups, but histological evaluation revealed significant impaired wound healing in the intervention group.

CONCLUSION

The incorporation of a PCL scaffold into a circular stapled rectal anastomosis did not increase anastomotic tensile strength in piglets and indicated an impaired histologically assessed wound healing.

Collagenase-producing bacteria are common in anastomotic leakage after colorectal surgery: a systematic review

PURPOSE

Some gut bacteria can produce enzymes (collagenases) that can break down collagen in the intestinal wall. This could be a part of the pathophysiology of anastomotic leakage (AL). This systematic review aimed to investigate if such bacteria were present more frequently in AL patients versus non-AL patients following colorectal surgery.

METHODS

This systematic review was reported according to the PRISMA and AMSTAR guidelines. Before the literature search, a study protocol was registered at PROSPERO (CRD42022363454). We searched PubMed, EMBASE, Google Scholar, and Cochrane CENTRAL on April 9th, 2023, for randomized and observational human studies of AL following colorectal surgery with information on gastrointestinal bacteria. The primary outcome was bacteria with the potential to produce collagenase. The risk of bias was assessed with the Newcastle-Ottawa Scale, as all studies were observational.

RESULTS

We included 15 studies, with a total of 52,945 patients, of which 1,747 had AL, and bacteriological information from feces, mucosa, the resected specimen, or drain fluid was presented. In 10 of the 15 studies, one or more collagenase-producing bacteria were identified in the patients with AL. Neither the bacteria nor the collagenase production were quantified in any of the studies. The studies varied greatly in terms of sample material, analytical method, and time of collection. Studies using DNA sequencing methods did not report findings of collagenase-producing bacteria.

CONCLUSION

Collagenase-producing bacteria are more common in patients with AL following colorectal surgery than in patients without AL, but the significance is unclear. From the current studies, it is not possible to determine the pathogenicity of the individual gut bacteria.

Surgical approaches to colonic and rectal anastomosis: systematic review and meta-analysis

PURPOSE

Postoperative complications after a colonic and rectal surgery are of significant concern to the surgical community. Although there are different techniques to perform anastomosis (i.e., handsewn, stapled, or compression), there is still no consensus on which technique provides the least number of postoperative problems. The objective of this study is to compare the different anastomotic techniques regarding the occurrence or duration of postoperative outcomes such as anastomotic dehiscence, mortality, reoperation, bleeding and stricture (as primary outcomes), and wound infection, intra-abdominal abscess, duration of surgery, and hospital stay (as secondary outcomes).

METHODS

Clinical trials published between January 1, 2010, and December 31, 2021, reporting anastomotic complications with any of the anastomotic technique were identified using the MEDLINE database. Only articles that clearly defined the anastomotic technique used, and report at least two of the outcomes defined were included.

RESULTS

This meta-analysis included 16 studies whose differences were related to the need of reoperation (p < 0.01) and the duration of surgery (p = 0.02), while for the anastomotic dehiscence, mortality, bleeding, stricture, wound infection, intra-abdominal abscess, and hospital stay, no significant differences were found. Compression anastomosis reported the lowest reoperation rate (3.64%) and the handsewn anastomosis the highest (9.49%). Despite this, more time to perform the surgery was required in compression anastomosis (183.47 min), with the handsewn being the fastest technique (139.92 min).

CONCLUSIONS

The evidence found was not sufficient to demonstrate which technique is most suitable to perform colonic and rectal anastomosis, since the postoperative complications were similar between the handsewn, stapled, or compression techniques.

Dysbiosis and Gastrointestinal Surgery: Current Insights and Future Research

Surgery of the gastrointestinal tract can result in deep changes among the gut commensals in terms of abundance, function and health consequences. Elective colorectal surgery can occur for neoplastic or inflammatory bowel disease; in these settings, microbiota imbalance is described as a preoperative condition, and it is linked to post-operative complications, as well. The study of bariatric patients led to several insights into the role of gut microbiota in obesity and after major surgical injuries. Preoperative dysbiosis and post-surgical microbiota reassessment are still poorly understood, and they could become a key part of preventing post-surgical complications. In the current review, we outline the most recent literature regarding agents and molecular pathways involved in pre- and post-operative dysbiosis in patients undergoing gastrointestinal surgery. Defining the standard method for microbiota assessment in these patients could set up the future approach and clinical practice.

Role of transanal drainage tubes in preventing anastomotic leakage after low anterior resection: a meta-analysis of randomized controlled trials

BACKGROUND

The transanal drainage tube (TDT) is thought to reduce the incidence of anastomotic leakage (AL) in patients with low anterior resection (LAR). However, results from different clinical trials are inconsistent, although nearly all meta-analyses agree on the efficacy. In contrast to results of many previous studies, 2 recent independent randomized controlled trials (RCTs) suggest that the use of TDT does not prevent AL. We performed a meta-analysis including only RCTs to compare patients with TDTs vs. those without TDTs in terms of AL rate.

METHODS

A systematic literature search was performed in the PubMed, Embase, Cochrane Library databases, Clinicaltrials.gov and WHO/ICTRP from inception until February 14, 2022. RCTs that evaluated the role of TDTs in AL prevention in patients who underwent LAR for rectal cancer were included. A meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were extracted by two authors independently, and random-effects models were implemented. The main outcome was AL, and the secondary outcome was the grade of AL.

RESULTS

Three RCTs were included involving a total of 1115 participants (559 patients in the TDT group and 556 in the non-TDT group). No significant difference in the AL rate was detected (RR = 0.69, 95% confidence interval (CI) 0.42-1.15, p = 0.15, I² = 21%, very low certainty evidence). The incidence of grade C AL was possibly lower in the TDT group (RR = 0.33, 95% CI 0.11-1.01, p = 0.05, very low certainty evidence), while the rate of grade B AL was similar between the two groups (RR = 1.17, 95% CI 0.66-2.08, p = 0.59, very low certainty evidence).

CONCLUSIONS

The present meta-analysis suggests that TDTs are not effective in reducing the overall incidence of AL, but possibly have a potential benefit in reducing the occurrence of grade C AL in patients with LAR. Based on the current limited data and existing heterogeneity, the inclusion of larger populations and the identification of more uniform indications for TDT need to be addressed in future studies.

Two-year follow-up results of the use of a fecal diverting device as a substitute for a defunctioning stoma

PURPOSE

Our previously published clinical studies described the short-term outcomes of a newly developed intraluminal fecal diverting device (FDD). FDD was a safe and effective substitute for a defunctioning stoma. However, the long-term efficacy and safety of this device remain unknown. We investigated the long-term outcomes of the use of the FDD as a substitute for a defunctioning stoma.

METHODS

We examined the medical records of patients who participated in our two previous FDD clinical studies. The main outcome was the number of patients with bowel continuity for 2 years after undergoing the FDD procedure or defunctioning stoma creation.

RESULTS

Between May 2015 and July 2018, 85 patients were screened for inclusion in this study. Of those, 27 patients underwent a defunctioning ileostomy after proctectomy. The remaining 58 underwent the FDD procedure after proctectomy. Seventy-two patients (ileostomy group, n = 22; FDD group, n = 50) with a follow-up duration > 24 months were included in this analysis. The mean duration of fecal diversion was significantly shorter (p < 0.001) in the FDD group (3.1 [1.6-6.1] weeks) than in the ileostomy group (16.7 [10.0-31.6] weeks). However, the rate of permanent stoma creation was not statistically different between the two groups (ileostomy and FDD groups, 13.6% [3/22] and 10.0% [5/50], respectively; p = 0.693).

CONCLUSIONS

The FDD procedure is a feasible substitute for a defunctioning stoma after proctectomy. Multicenter large-scaled clinical studies are required to validate our results.

Evaluation of the SafeHeal Colovac+ Anastomosis Protection Device: A Preclinical Study

BackgroundThe protective ostomy is the current standard of care to protect a low colorectal anastomosis from leakage, but exposes patients to complications requiring an alternative strategy. The Colovac+ is a vacuum-based intraluminal bypass device designed to shield the anastomosis from fecal content, preventing the clinical outcomes of anastomotic leakage. The objective of this study was to evaluate the preliminary efficacy, safety, and technical feasibility of the Colovac+ in a porcine model. Methods: Twelve pigs received a colorectal anastomosis with Colovac+ implantation. The device was left in situ for 10 days and then retrieved endoscopically. Six pigs were to be sacrificed immediately after device retrieval and the other 6 were to be sacrificed on day 38. Clinical, endoscopic, and histopathological examinations were performed to evaluate the following endpoints: prevention of contact between the anastomosis and fecal content, device migration, feasibility of the implantation and retrieval procedure, collateral damage to the colonic wall, colon healing after device retrieval, and systemic toxicity related to the device. Results: Eleven pigs completed the study. One pig died prematurely due to a surgical complication unrelated to the device (bladder damage with uroperitoneum). There was no evidence of contact between the anastomosis and fecal content, none of the pigs developed symptomatic anastomotic leakage, there were no significant device migrations, and there was no evidence of systemic toxicity. Colovac+ implantation was easily performed in all cases except 1 (due to an inappropriate lubricant). Colovac+ retrieval was achieved successfully in all cases. Postretrieval examinations on day 10 revealed ulcerations at the anchoring site in 4 cases indicating mechanical damage caused by the stent. However, in the recovery group, no ulcerations were observed on day 38, and the colonic wall had properly healed in all animals. Conclusions: The Colovac+ is a technically feasible, safe, and efficient device for the protection of a colorectal anastomosis in a porcine model. The device holds promise for clinical use and warrants further research.

New Technologies to Prevent Anastomotic Leak

Leaks from anastomoses can be a serious complication of any gastrointestinal resection. Leaks lead to increased morbidity, delayed postoperative recovery, and potential delays in adjuvant treatment in cancer cases. Prevention of anastomotic leak has been an area of ongoing research for decades. Methods of assessing bowel perfusion have been developed that may provide forewarning of anastomotic compromise. Physical reinforcement of the anastomosis with buttressing material is an available method employed with the goal of preventing leaks. Liquid-based sealants have also been explored. Lastly, interactions between the gut microbiome and anastomotic healing have been investigated as a mean of manipulating the microenvironment to reduce leak rates. Though no single technology has been successful in eliminating leaks, an understanding of these developing fields will be important for all surgeons who operate on the gastrointestinal tract.

The effects of preoperative intestinal dysbacteriosis on postoperative recovery in colorectal cancer surgery: a prospective cohort study

Background

Accumulating evidence suggests a critical role of intestinal dysbacteriosis in surgical site infections and anastomotic leakage after abdominal surgery. However, a direct correlation between pre-existing dysbacteriosis and postoperative infectious complications has not yet been established clinically.

Methods

A total of 353 consecutive patients who underwent colorectal cancer (CRC) surgery were enrolled. Gram-stained faecal smears were tested at admission and the first defecation after surgery. Intestinal dysbacteriosis was graded into three groups: normal or slightly decreased intestinal microflora (grade 1), moderate dysbacteriosis (grade 2), and severe dysbacteriosis (grade 3). Clinical outcomes were postoperative infections and anastomotic leakage within 30 days after surgery.

Results

At the preoperative assessment, 268 (75.9%) patients had normal or slightly decreased intestinal microflora, 58 (16.4%) patients had moderate dysbacteriosis, and 27 (7.6%) patients had severe dysbacteriosis. The patients with preoperative dysbacteriosis had a higher rate of early postoperative diarrhoea (grade 2: OR = 4.53, 95% CI 2.28–9.00, grade 3: OR = 4.52, 95% CI 1.81–11.31), total complications (grade 3 40.7% vs. grade 2 25.9% vs. grade 1 12.7%, P < 0.001), and anastomotic leakage (grade 3 11.1% vs. grade 2 5.2% vs. grade 1 1.5%, P = 0.002). An interaction effect among preoperative dysbacteriosis and early postoperative diarrhoea on total complications was observed in rectal cancer patients (P for interaction = 0.007).

Conclusions

An imbalance of the intestinal microbiome exists in a considerable proportion of CRC patients before surgery. Preoperative dysbacteriosis is associated with higher rates of early postoperative diarrhoea, which further correlates with infectious complications and anastomotic leakage. However, the contribution of preoperative dysbacteriosis to the occurrence of anastomotic leakage needs to be clarified in further studies.

Trial registration ChiCTR, ChiCTR1800018755. Registered 8 October 2018—Retrospectively registered, http://www.chictr.org.cn/ChiCTR1800018755.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02035-6.

Anastomotic Leak: Toward an Understanding of Its Root Causes

BACKGROUND

When an anastomotic leak is discussed at a typical surgical morbidity and mortality conference, it is often presented as a due to an error in surgical technique involving ischemia, tension, or device failure. Here we assert that without direct visual analysis of the leak site and its tissue histology, an ex post facto claim that an anastomotic leak is due to an error in surgical technique remains speculative.

METHODS

The arguments and rationale used to conclude that an anastomotic leak is due to an error in surgical technique are critically reviewed and assessed for their validity.

RESULTS

No case series or literature exists in which a root cause analysis has been carried out with visual and tissue level evidence to determine the root cause(s) of an anastomotic leak.

CONCLUSIONS

At the individual case level, declaring that an anastomotic leak is due to an error in surgical technique without clear and compelling evidence either visually and/or at the tissue level to substantiate such a claim remains speculative.

Use of transanal drainage tube to prevent anastomotic leakage: intangible differences between the East and the West

Trans-anal drainage tube is used to reduce the rectal pressure, especially at the anastomotic site and thus to protect the anastomosis. Ideally it serves as and even may replace a diverting stoma. When compared to no treatment, the effectiveness of TDT seems confirmed based on the literature, but it remains uncertain whether TDT can replace the diverting stoma. Despite the insignificant tangible costs of TDT, it seems different cultures put varied weight on the intangible costs such as discomfort and pain to patients after surgery.

Mucosa plication reinforced colorectal anastomosis and trans-anal vacuum drainage: a pilot study with preliminary results

Dehiscence of colorectal anastomosis is a serious complication that is associated with increased mortality, impaired functional and oncological outcomes. The hypothesis was that anastomosis reinforcement and vacuum trans-anal drainage could eliminate some risk factors, such as mechanically stapled anastomosis instability and local infection. Patients with rectal cancer within 10 cm of the anal verge and low anterior resection with double-stapled technique were included consecutively. A stapler anastomosis was supplemented by trans-anal reinforcement and vacuum drainage using a povidone-iodine-soaked sponge. Modified reinforcement using a circular mucosa plication was developed and used. Patients were followed up by postoperative endoscopy and outcomes were acute leak rate, morbidity, and diversion rate. The procedure was successfully completed in 52 from 54 patients during time period January 2019–October 2020. The mean age of patients was 61 years (lower–upper quartiles 54–69 years). There were 38/52 (73%) males and 14/52 (27%) females; the neoadjuvant radiotherapy was indicated in a group of patients in 24/52 (46%). The mean level of anastomosis was 3.8 cm (lower–upper quartiles 3.00–4.88 cm). The overall morbidity was 32.6% (17/52) and Clavien–Dindo complications ≥ 3 grade appeared in 3/52 (5.7%) patients. No loss of anastomosis was recorded and no patient died postoperatively. The symptomatic anastomotic leak was recorded in 2 (3.8%) patients and asymptomatic blind fistula was recorded in one patient 1/52 (1.9%). Diversion ileostomy was created in 1/52 patient (1.9%). Reinforcement of double-stapled anastomosis using a circular mucosa plication with combination of vacuum povidone-iodine-soaked sponge drainage led to a low acute leak and diversion rate. This pilot study requires further investigation.

Registered at ClinicalTrials.gov.: Trial registration number is NCT04735107, date of registration February 2, 2021, registered retrospectively.

Incorporation of a Poly-ε-Caprolactone Scaffold in a ;Circular Stapled End-To-End Small Intestine Anastomosis Does Not Have Any Adverse Effects Within 30 days: A Study in Piglets

Background. Incorporation of a poly-ε-caprolactone (PCL) scaffold in circular stapled anastomoses has been shown to increase the anastomotic tensile strength on postoperative day (POD) 5 in a pig model. The aim of this study was to investigate the effects of incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis, with stricture formation and anastomotic histology as primary outcomes in a 30-day observation period. Methods. A total of 15 piglets were included. In each piglet, three circular stapled end-to-end anastomoses were made in the small intestines. Two were interventional and one was a control. On POD 10, 20, or 30, the anastomoses were subjected to in vivo intraluminal contrast study, and the index for anastomotic lumen was calculated. The anastomotic segment was resected and subjected to a tensile strength test and histological examination. Results. At POD 10, the mean ± SD value for anastomotic index was .749 ± .065 in control anastomoses and .637 ± .051 in interventional anastomosis (P = .0046), at POD 20, .541 ± .150 and .724 ± .07 (P = .051), and at POD 30, .645 ± .103 and .686 ± .057 (P = .341), respectively. No significant difference was observed in maximum tensile strength and histology at POD 30. Conclusions. The incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis does not increase the risk of stricture or impair wound healing after 30 days.

Intraluminal bypass devices as an alternative to protective ostomy for prevention of colorectal anastomotic leakage: a systematic review of the literature

AIM

Anastomotic leakage (AL) is the most important complication of colorectal surgery, leading to high morbidity and mortality. Protective ostomy, the current standard of care for protecting a colorectal anastomosis, has important drawbacks that require the creation of an alternative strategy. Over the past 30 years, several intraluminal bypass devices, designed to shield the anastomosis from the faecal stream, have been developed. The aim of this literature review was to create an updated overview of the devices available and their effectiveness in preventing AL, and to investigate whether they could serve as an alternative to protective ostomy in the future.

METHOD

A systematic review of the literature on intraluminal bypass devices used for preventing colorectal AL was performed. The MEDLINE and Cochrane Library databases were searched, and articles were marked as relevant if an intraluminal bypass device was studied in an animal or human population.

RESULTS

The database search yielded 24 relevant articles related to 10 intraluminal bypass devices protecting a colorectal anastomosis. These articles included experimental animal studies, preclinical (pilot) studies, as well as retrospective and prospective clinical studies. Each device was assessed with regard to surgical technique, effectiveness and device-related complications.

CONCLUSION

Intraluminal bypass devices show promise in preventing AL and its clinical consequences. However, there is insufficient high-level evidence to draw firm conclusions. There is a need for randomized controlled trials that directly compare these devices with the protective ostomy.

Intestinal Microbiota in Colorectal Cancer Surgery

Simple Summary

The microbial communities of the intestine exist in a delicate balance with the human. Colorectal cancer is one of the most common gastrointestinal malignancies, and the microbiota seems to be related to it. The intestinal microbiota of patients after colorectal surgery is changed due to surgical stress and other perioperative factors. The occurrence of complications after colorectal cancer (CRC) surgery may depend on these bacterial shifts, which could also be associated with prognosis and survival in postoperative CRC patients.

Abstract

The intestinal microbiota consists of numerous microbial species that collectively interact with the host, playing a crucial role in health and disease. Colorectal cancer is well-known to be related to dysbiotic alterations in intestinal microbiota. It is evident that the microbiota is significantly affected by colorectal surgery in combination with the various perioperative interventions, mainly mechanical bowel preparation and antibiotic prophylaxis. The altered postoperative composition of intestinal microbiota could lead to an enhanced virulence, proliferation of pathogens, and diminishment of beneficial microorganisms resulting in severe complications including anastomotic leakage and surgical site infections. Moreover, the intestinal microbiota could be utilized as a possible biomarker in predicting long-term outcomes after surgical CRC treatment. Understanding the underlying mechanisms of these interactions will further support the establishment of genomic mapping of intestinal microbiota in the management of patients undergoing CRC surgery.

Innovative approaches for induction of gastrointestinal anastomotic healing: an update on experimental and clinical aspects

PURPOSE

In most cases, traditional techniques to perform an anastomosis following gastrointestinal resections lead to successful healing. However, despite focused research in the field, in certain high-risk situations leakage rates remain almost unchanged. Here, additional techniques may help the surgeon to protect the anastomosis and prevent leakage. We give an overview of some of the latest developments on experimental and clinical techniques for induction of anastomotic healing.

METHODS

We performed a review of the current literature on approaches to improve anastomotic healing.

RESULTS

Many promising approaches with a high clinical potential are in the developmental pipeline. Highly experimental approaches like inhibition of matrix metalloproteinases, stem cell therapy, hyperbaric oxygen therapy, induction of the hypoxic adaptive response, and the administration of growth factors are still in the preclinical phase. Other more clinical developments aim to strengthen the anastomotic suture line mechanically while shielding it from the influence of the microbiome. Among them are gluing, seaming the staple line, attachment of laminar biomaterials, and temporary intraluminal tubes. In addition, individualized bowel preparation, selectively reducing certain detrimental microbial populations could become the next stage of bowel preparation. Compression anastomoses are evolving as an equivalent technique additional to established hand-sewn and stapled anastomoses. Fluorescence angiography and flexible endoscopy could complement intraoperative quality control additionally to the air leak tests. Virtual ileostomy is a concept to prepare the bowel for the easy formation of a stoma in case of leakage.

CONCLUSION

A variety of promising diagnostic and prophylactic measures that may support the surgeon in identifying high-risk anastomoses and support them according to their potential deficits is currently in development.

In vitro degradation profiles and in vivo biomaterial-tissue interactions of microwell array delivery devices

To effectively apply microwell array cell delivery devices their biodegradation rate must be tailored towards their intended use and implantation location. Two microwell array devices with distinct degradation profiles, either suitable for the fabrication of retrievable systems in the case of slow degradation, or cell delivery systems capable of extensive remodeling using a fast degrading polymer, were compared in this study. Thin films of a poly(ethylene glycol)‐poly(butylene terephthalate) (PEOT‐PBT) and a poly(ester urethane) were evaluated for their in vitro degradation profiles over 34 weeks incubation in PBS at different pH values. The PEOT‐PBT films showed minimal in vitro degradation over time, while the poly(ester urethane) films showed extensive degradation and fragmentation over time. Subsequently, microwell array cell delivery devices were fabricated from these polymers and intraperitoneally implanted in Albino Oxford rats to study their biocompatibility over a 12‐week period. The PEOT‐PBT implants shown to be capable to maintain the microwell structure over time. Implants provoked a foreign body response resulting in multilayer fibrosis that integrated into the surrounding tissue. The poly(ester urethane) implants showed a loss of the microwell structures over time, as well as a fibrotic response until the onset of fragmentation, at least 4 weeks post implantation. It was concluded that the PEOT‐PBT implants could be used as retrievable cell delivery devices while the poly(ester urethane) implants could be used for cell delivery devices that require remodeling within a 4–12 week period.

Can the microbiota predict response to systemic cancer therapy, surgical outcomes, and survival? The answer is in the gut

INTRODUCTION

The gut microbiota seems to play a key role in tumorigenesis, across various hallmarks of cancer. Recent evidence suggests its potential use as a biomarker predicting drug response and adding prognostic information, generally in the context of immuno-oncology.

AREAS COVERED

In this review, we focus on the modulating effects of gut microbiota dysbiosis on various anticancer molecules used in practice, including cytotoxic and immune-modulating agents, primarily immune-checkpoint inhibitors (ICI). Pubmed/Medline-based literature search was conducted to find potential original studies that discuss gut microbiota as a prognostic and predictive biomarker for cancer therapy. We also looked at the US ClinicalTrials.gov website to find additional studies particularly ongoing human clinical trials.

EXPERT COMMENTARY

Sequencing of stool-derived materials and tissue samples from cancer patients and animal models has shown a significant enrichment of various bacteria such as Fusobacterium nucleatum and Bacteroides fragilis were associated with resistant disease and poorer outcomes. Gut microbiota was also found to be associated with surgical outcomes and seems to play a significant role in anastomotic leak (ATL) after surgery mainly by collagen breakdown. However, this research field is just at the beginning and the current findings are not yet ready to change clinical practice.

Current evidence on the relation between gut microbiota and intestinal anastomotic leak in colorectal surgery

BACKGROUND

Anastomotic leak (AL) is a major complication in colorectal surgery. It worsens morbidity, mortality and oncological outcomes in colorectal cancer. Some evidence suggests a potential effect of the intestinal microbiome on wound healing. This review aims to provide a comprehensive review on historical and current evidence regarding the relation between the gastrointestinal microbiota and AL in colorectal surgery, and the potential microbiota-modifying effect of some perioperative commonly used measures.

DATA SOURCES

A comprehensive search was conducted in Pubmed, Medline and Embase for historical and current clinical and animal studies addressing perioperative intestinal microbiota evaluation, intestinal healing and AL.

CONCLUSIONS

Evidence on microbes' role in AL is mainly derived from animal experiments. The microbiota's composition and implications are poorly understood in surgical patients. Elaborate microbiota sequencing is required in colorectal surgery to identify potentially beneficial microbial profiles that could lead to specific perioperative microbiome-altering measures and improve surgical and oncological outcomes.

Assessment of a Vacuum-Based Intra-Colonic Diverting Device: A Preclinical Study

Purpose. Anastomotic leak is the main complication after low colorectal anastomosis. Defunctioning ileostomy is therefore recommended, which carries its own morbidity. The aim of this study was to assess the technical feasibility, safety, and preliminary efficacy of a vacuum-based intra-colonic diverting device (Colovac) to reduce the impact of anastomotic leak. Methods. This prospective preclinical study was conducted on living swine. The device was surgically inserted transanally, proximal to a colorectal anastomosis, and removed endoscopically at day 14. Then, open surgery was performed to look for deep sepsis and/or anastomotic leak, and the remaining colorectal anastomosis was resected for histopathological analysis. The endpoints were successful insertion and delivery of the device, postoperative morbidity, successful maintaining of the device, and absence of feces spillage and/or abscess in the abdominal cavity. Results. The Colovac was inserted in 22 swine. Stent migration occurred in 7 of the first 8 specimens, leading to natural expulsion of the device. After diet adaptation, a subsequent group of 14 swine was undertaken, of which 13 did not show any sign of migration post-implantation. Disconnection of the suction drain occurred in 1 case, leading to device expulsion on day 10. Colovac retrieval was achieved successfully in 13 cases. The endoscopic assessment of the anchorage site showed limited mucosal injury, whereas histopathological findings revealed mild hyperplasia. One swine died prematurely of postoperative colonic ischemia. Conclusion. This new device appears to be safe in the swine model and may prevent peritonitis or abscess due to colorectal anastomotic leak.

The effectiveness of a fecal diverting device for prevention of septic complications in a dog model of ischemic bowel anastomosis

OBJECTIVE

A type of bypass tube for a fecal diversion device (FDD) was created to protect colorectal anastomosis. We evaluated the effectiveness of the FDD in an animal study.

METHODS

The study was performed in an experimental animal laboratory of a tertiary referral center hospital. Thirty mongrel dogs were randomized to the FDD or control group (n = 15, each). An ischemic anastomosis model was used to readily produce anastomotic leakage (AL) in both groups. The FDD was fixed intraluminally at 10 cm above the anastomotic site in the FDD group. No protective methods were used in the control group. The postoperative observation period was 3 weeks.

RESULTS

The 3 week-survival rates were higher in the FDD group compare with the control group (80%, 12/15 vs. 40%, 6/15; log-rank, P = 0.024). The incidence of AL causing generalized peritonitis was lower in the FDD group than in the control group (20.0%, 3/15 vs. 60.0%, 9/15; P = 0.025) despite the overall incidence of complications being similar in the both groups (53.3%, 8/15 vs. 66.7%, 10/15; P = 0.456). Colonic wall erosions in the FDD fixing area were seen in two subjects (13.3%) in the FDD group. However, the two subjects survived to the end of the experimental period. In the FDD group, five subjects (33.3%, 5/15) did not retain their FDD, and three among them died from generalized peritonitis.

CONCLUSION

This study shows the effectiveness of the FDD at preventing septic complications in a dog model of ischemic bowel anastomosis.

Impact of omentoplasty on anastomotic leak and septic complications after low pelvic anastomosis: a study from the NSQIP database

PURPOSE

The role of omentoplasty in the prevention of anastomotic leak (AL) in colorectal surgery is controversial. The aim of this study was to evaluate the impact of omentoplasty on AL and septic complications after low pelvic anastomosis using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

METHODS

The ACS-NSQIP database was queried for patients who underwent segmental colectomy with low pelvic anastomosis by using 2012 targeted colectomy participant use data file. Patients were divided into two groups according to omentoplasty versus no-omentoplasty formation. AL and surgical site infections (SSIs) within postoperative 30 days were compared between the groups.

RESULTS

A total of 2891 patients (1447 [50.1%] males) with a mean age of 60.2 ± 13.0 years met the inclusion criteria. There were 86 (2.9%) and 2805 (97.1%) patients in the omentoplasty and no-omentoplasty group, respectively. In the multivariate analysis, omentoplasty neither reduced AL (p = 0.83; OR = 0.88, 95% CI, 0.21-2.44) nor organ/space SSIs (p = 0.08; OR = 2.14, 95% CI, 0.91-4.41). Also, this technique did not play any role in reducing AL and organ/space SSI rates regardless of diversion with the exception of its association with higher organ/space SSIs in patients without diverting stoma (9.2% vs 3.8%, p = 0.04). No differences were detected between the groups with respect to the management strategies for AL (p = 0.22).

CONCLUSIONS

Omentoplasty did not decrease AL and septic complications after low pelvic anastomosis and had no impact on the postoperative management of AL.

The use of a novel adhesive tissue patch as an aid to anastomotic healing

Introduction One of the most feared complications of colorectal surgery is anastomotic leak. Numerous techniques have been studied in the hope of decreasing leakage. This study was designed to assess the handling characteristics of a novel adhesive tissue patch (TissuePatch™; Tissuemed, Leeds, UK) applied to colorectal anastomoses in a pilot study. This was with a view to assessing its potential role in aiding anastomotic healing in subsequent trials. Methods A patch was applied to colorectal anastomoses after the surgeon had completed the anastomosis and prior to abdominal closure. Handling characteristics and patient outcomes were recorded prospectively. Results Nine patients were recruited before the study was prematurely terminated. In one patient, the patch fell off and in another patient, the surgeon omitted to apply it. Six patients had significant postoperative problems (1 confirmed leak necessitating return to theatre and excision anastomosis, 3 suspicious of leak on computed tomography delaying discharge, 2 perianastomotic collections). One patient had an uneventful recovery. Conclusions Although the handling characteristics of this novel tissue patch were deemed satisfactory, it appears that wrapping a colorectal anastomosis with an adhesive hydrophilic patch has significant deleterious effects on anastomotic healing. This could be a consequence of the creation of a microenvironment between the patch and the anastomosis that impairs healing. Further research is required to better understand the mechanisms involved. At present, the use of such patches on colorectal anastomoses should be discouraged outside the confines of a well monitored trial.

Stercoral perforation proximal to the stapled anastomosis after low anterior resection with an intraluminal device

Stercoral perforation of the colon is a rare phenomenon and a potential life-threatening condition requiring acute intervention. A little more than 200 cases have been described to date. The mechanism is not completely understood. In this short communication, we present three patients with a colon perforation proximal to the anastomosis, similar to a stercoral perforation, following colorectal cancer resection with application of an intraluminal device, the C-seal.