Colorectal anastomotic leakage: a narrative review of definitions, grading systems, and consequences of leaks.

Background: Anastomotic leaks (ALs) are a significant and feared postoperative complication, with incidence of up to 30% despite advances in surgical techniques. With implications such as additional interventions, prolonged hospital stays, and hospital readmission, ALs have important impacts at the level of individual patients and healthcare providers, as well as healthcare systems as a whole. Challenges in developing unified definitions and grading systems for leaks have proved problematic, despite acknowledgement that colorectal AL is a critical issue in intestinal surgery with serious consequences. The aim of this study was to construct a narrative review of literature surrounding definitions and grading systems for ALs, and consequences of this postoperative complication. Methods: A literature review was conducted by examining databases including PubMed, Web of Science, OVID Embase, Google Scholar, and Cochrane library databases. Searches were performed with the following keywords: anastomosis, anastomotic leak, colorectal, surgery, grading system, complications, risk factors, and consequences. Publications that were retrieved underwent further assessment to ensure other relevant publications were identified and included. Results: A universally accepted definition and grading system for ALs continues to be lacking, leading to variability in reported incidence in the literature. Additional factors add to variability in estimates, including differences in the anastomotic site and institutional/individual differences in operative technique. Various groups have worked to publish guidelines for defining and grading AL, with the International Study Group of Rectal Cancer (ISGRC/ISREC) definition the current most recommended universal definition for colorectal AL. The burden of AL on patients, healthcare providers, and hospitals is well documented in evidence from leak consequences, such as increased morbidity and mortality, higher reoperation rates, and increased readmission rates, among others. Conclusions: Colorectal AL remains a significant challenge in intestinal surgery, despite medical advancements. Understanding the progress made in defining and grading leaks, as well as the range of negative outcomes that arise from AL, is crucial in improving patient care, reduce surgical mortality, and drive further advancements in earlier detection and treatment of AL.

Colonic Anastomotic Leak Model in Swine.

INTRODUCTION: Anastomotic leaks (ALs) are serious postoperative complications. Current experimental studies designed to investigate leaks are based on acute intraoperative dehiscence of the anastomosis. Clinically, however, AL usually happens later in the postoperative course. Presented here is a clinically relevant colonic AL model in swine. METHODS: Seventeen Yorkshire pigs were divided into 2 groups: the control group (n = 6) and the experimental group (n = 11). An enterotomy was performed on the descending colon and an end-to-end handsewn anastomosis was created in the groups. The proximal and distal ends of the suture were exteriorized and tied to a plastic tube. Subsequently, the suture was cut and pulled to induce breakdown of the anastomosis in the experimental group 3-4 h postoperatively. Study endpoints included behavioral changes, clinical assessment, laboratory indicators, and macroscopic indicators of leakage. RESULTS: Leaks were successfully created in 8/11 of the experimental group animals and confirmed through exploratory relaparotomy. Seven of the experimental pigs showed complete anastomotic breakdown and one showed partial rupture. Fecal peritonitis and enteric spillage were observed macroscopically within the abdomen of the experimental pigs, confirming the presence of a leak. The remaining (3/11) experimental pigs did not experience those findings due to either a tamponade/containment by the abdominal wall or surrounding organs. Statistical significance (p < 0.05) was achieved between the experimental and control cohorts for laboratory and clinical indicators including fever, leukocytosis, and decreased blood potassium. CONCLUSION: This animal model generated postoperative induced leak in approximately three-quarters (8/11) of experimental pigs, allowing control over the time of leak onset to simulate clinical settings.

Continuous pH monitoring using a sensor for the early detection of anastomotic leaks.

Anastomotic leaks (AL) and staple line leaks are a serious post-operative complication that can develop following bariatric surgery. The delay in the onset of symptoms following a leak usually results in reactive diagnostics and treatment, leading to increased patient morbidity and mortality, and a clinical and economic burden on both the patient and the hospital. Despite support in literature for pH as a biomarker for early detection of AL, the current methods of pH detection require significant clinician involvement and resources. Presented here is a polyaniline (PANI)-based pH sensor that can be connected inline to surgical drains to continuously monitor peritoneal secretion in real time for homeostatic changes in pH. During this study, the baseline peritoneal fluid pH was measured in two pigs using the PANI sensor and verified using a benchtop pH probe. The PANI sensor was then utilized to continuously monitor the changes in the pH of peritoneal effluent, as a gastric leak was simulated. The inline sensors were able to detect the resulting local changes in drainage pH within 10 min of leak induction. The successful implementation of this sensor in clinical practice can both enable high efficiency continuous monitoring of patient status and drastically decrease the time required to detect AL, thus potentially decreasing the clinical and economic burden incurred by gastric leaks.