Circular anastomotic experimental fibrin sealant protection in deep colorectal anastomosis in pigs in a randomized 9-day survival study

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.

Clinical results after external reinforcement of colorectal anastomosis: a systematic review

OBJECTIVE

The aim of this review is to describe and assess the existing methods to cover colorectal anastomoses with biomaterials and their clinical impact in reducing anastomotic leakage (AL).

SUMMARY BACKGROUND DATA

The most serious complication in colorectal surgery is AL. Despite improvements in its diagnosis and management, AL remains an unresolved issue. To prevent its appearance and clinical consequences, different external reinforcement techniques with synthetic or biomaterials have been described.

METHODS

A systematic review search of the available literature until June 2022 was performed, looking for all literature regarding external reinforcement of colonic or colorectal anastomoses. After the review process, a classification of materials was proposed into solid and liquid materials, and an assessment of their clinical impact was performed. The study protocol has been registered at PROSPERO and has been reported in the line with PRISMA and AMSTAR Guidelines 11,12 .

RESULTS

Ninety-seven articles that fulfilled inclusion criteria, were identified and revised. Overall, 18 of the selected articles focused on human clinical trials and 79 on animal models. Only fibrin sealants, collagen patches, and omentoplasty have shown positive results in humans.

CONCLUSIONS

Fibrin sealants, collagen patches, and omentoplasty are, so far, the most studied biomaterials. However, further studies are required to confirm these findings before definite recommendations can be made.

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.

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.

Is Circular Fibrin Sealing of Low Rectal Anastomosis Able to Prevent Leakage in 21-Day Follow-up? Randomized Experimental Trial in Pigs

Purpose. Clinically apparent anastomotic leakage (AL) after low anterior rectal resection (LAR; <7 cm from anal verge) using circular double-stapled anastomosis without defunctioning stoma is up to 37.5%. However, it is unclear whether there is reduction of LAR after 21 postoperative days without defunctioning stoma but with extraluminal anastomotic application of fibrin sealant. Methods. Forty-eight-week-old pigs underwent LAR and circular double-stapled anastomosis in end-to-end technique (descendo-rectostomy). Animals were randomized into therapy and control group (cg). Therapy group (n = 20) received additional extraluminal circular anastomotic application of fibrin sealant. Objective was to assess incidence of clinically apparent and nonclinically apparent leakage through the 21st postoperative day. Remaining animals were sacrificed on the 21st day, and anastomotic region was analyzed. In case of earlier diagnosed AL, animals were sacrificed. Results. In cg, we observed clinically and nonclinically AL in 20% (n = 4). No animal was identified with a nonclinical-apparent leakage in this group, and all 4 animals with leakages presented clinical signs. In the therapy group, no animal (0/20) developed clinically apparent leakage signs. There were no leakages in this group, but 3 animals had ulcerative lesions without leak and without clinical signs. These lesions were observed intraluminally at crossing of staple lines after 21 days. In one of these animals, incomplete leakage was observed, blocked by fibrin sealant. Conclusion. In circular stapled colorectal anastomosis, circular fibrin glue sealant successfully protected anastomotic intraluminal wall defects at crossing of staple lines, reducing leakage rate from 20% to 0% (cg vs therapy group) after 21 postoperative days.

Human Amniotic Membrane Is Not Suitable for the Grafting of Colon Lesions and Prevention of Adhesions in a Xenograft Rat Model

INTRODUCTION

New biological materials are needed for specific applications in reconstructive bowel surgery and for the prevention of adhesion formation. Amniotic membranes (AMs) are assumed to have a number of unique characteristics that enhance the ingrowth of the surrounding tissue. The aim of the present study was to provide proof of these qualities in a xenograft model.

MATERIALS AND METHODS

A multilayer human AM (HAM) was applied to repair defined colon wall defects in Sprague-Dawley rats (n = 18). The control group was repaired with a suture (n = 6). The animals were killed humanely at 7, 21, and 42 days after implantation. Adhesions and perioperative complications were examined. Histological and immunohistological analyses were performed to assess a number of parameters, including degradation of the HAM, inflammation, graft rejection, and smooth muscle ingrowth.

RESULTS

Two rats in the treated group died. No other severe complications were observed. Adhesion formation was more prominently visible in the HAM group ( P < .05). The initially increased inflammation in the HAM group reduced over time but remained significantly increased ( P < .05). The HAM degraded over time and a subtle transient glomerulitis could be observed.

CONCLUSION

HAMs were found to increase adhesion formation and were not suitable for bowel augmentation in the presented xenograft model.