Anastomotic Troubleshooting

Anastomotic leak remains a critical and feared complication in colorectal surgery. The development of a leak can be catastrophic for a patient, resulting in overall increased morbidity and mortality. To help mitigate this risk, there are several ways to assess and potentially validate the integrity of a new anastomosis to give the patient the best chance of avoiding this postoperative complication. A majority of anastomoses will appear intact with no obvious sign of anastomotic dehiscence on gross examination. However, each anastomosis should be interrogated before the conclusion of an operation. The most common method to assess for an anastomotic leak is the air leak test (ALT). The ALT is a safe intraoperative method utilized to test the integrity of left-sided colon and rectal anastomoses and most importantly allows the ability to repair a failed test before concluding the operation. Additional troubleshooting is sometimes needed due to technical difficulties with the circular stapler. Problems, such as incomplete doughnuts and stapler misfiring, do occur and each surgeon should be prepared to address them.

Diagnosis of Anastomotic Leak

Anastomotic leaks after colorectal surgery is associated with increased morbidity and mortality. Understanding the impact of anastomotic leaks and their risk factors can help the surgeon avoid any modifiable pitfalls. The diagnosis of an anastomotic leak can be elusive but can be discerned by the patient's global clinical assessment, adjunctive laboratory data and radiological assessment. The use of inflammatory markers such as C-Reactive Protein and Procalcitonin have recently gained traction as harbingers for a leak. A CT scan and/or a water soluble contrast study can further elucidate the location and severity of a leak. Further intervention is then individualized on the spectrum of simple observation with resolution or surgical intervention.

Diagnosis and Management of Chronic Anastomotic Leak

Chronic anastomotic leaks present a daunting challenge to colorectal surgeons. Unfortunately, anastomotic leaks are common, and a significant number of leaks are diagnosed in a delayed fashion. The clinical presentation of these chronic leaks can be silent or have low grade, indolent symptoms. Operative options can be quite formidable and highly complex. Leaks are typically diagnosed by radiographic and endoscopic imaging during the preoperative assessment prior to defunctioning stoma reversal. The operative strategy depends on the location of the anastomosis and the specific features of the anastomotic dehiscence. Low colorectal anastomosis (i.e. following low anterior resection) may require a transanal approach, transabdominal approach, or a combination of the two. While restoration of bowel continuity is encouraged, it is not infrequent for a permanent ostomy to be required to maximize patient quality of life.

Treatment Modalities for Anastomotic Leakage in Rectal Cancer Surgery

Despite advances in rectal cancer surgery, anastomotic leakage (AL) remains a common complication with a significant impact on patient recovery, health care costs, and oncologic outcomes. The spectrum of clinical severity associated with AL is broad, and treatment options are diverse with highly variable practices across the colorectal community. To be effective, the treatment must match not only the patient's current status but also the type of leak, the surgeon's skill, and the resources available. In this chapter, we will review the current and emergent treatment modalities for AL after rectal cancer surgery.

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.

Risk Factors for Anastomotic Leak, Consideration for Proximal Diversion, and Appropriate Use of Drains

Anastomotic leaks are a major source of morbidity after colorectal surgery. There is a myriad of risk factors that may contribute to anastomotic leaks. These risk factors can be categorized as modifiable, nonmodifiable, and intraoperative factors. Identification of these risk factors allows for preoperative optimization that may minimize the risk of anastomotic leak. Knowledge of such high-risk features may also affect intraoperative decision-making regarding the creation of an anastomosis, consideration for proximal diversion, or placement of a drain. A thorough understanding of the interplay between risk factors, indications for proximal diversion, and utility of drain placement is imperative for colorectal surgeons.

Influence of the Microbiome on Anastomotic Leak

Despite advances in surgical technique and the expanded use of antibiotics, anastomotic leak remains a dreaded complication leading to increased hospital length of stay, morbidity, mortality, and cost. Data continues to grow addressing the importance of a functional and diverse colonic microbiome to ensure adequate healing. Individual pathogens, such as Enterococcus faecalis and Pseudomonas aeruginosa, have been implicated in the pathogenesis of anastomotic leak. Yet how these pathogens proliferate remains unclear. It is possible that decreased microbial diversity promotes a shift to a pathologic phenotype among the remaining microbiota which may lead to anastomotic breakdown. As the microbiome is highly influenced by diet, antibiotic use, the stress of surgery, and opioid use, these factors may be modifiable at various phases of the surgical process. A large amount of data remains unknown about the composition and behavior of the “normal” gut microbiome as compared with an altered community. Therefore, targeting the gut microbiome as a modifiable factor in anastomotic healing may represent a novel strategy for the prevention of anastomotic leak.

Anastomotic Leak after Ileal Pouch–Anal Anastomosis

There are special considerations when treating anastomotic leak after restorative proctocolectomy and ileal pouch–anal anastomosis. The epidemiology, risk factors, anatomic considerations, diagnosis and management, as well as the short- and long-term consequences to the patient are unique to this patent population. Additionally, there are specific concerns such as “tip of the J” leaks, transanal management of anastomotic leak/presacral sinus, functional outcomes after leak, and considerations of redo pouch procedures.