Anastomotic failure is one of the most feared complications of gastrointestinal surgery due to the resultant morbidity and mortality. Failure of an anastomosis, or intestinal junction, can cause a spectrum of morbidities to the patient including local abscess formation - requiring procedural drainage, tumor recurrence, debilitating pain, dysfunctional defecation, and overwhelming bacterial sepsis resulting in death. Despite improvements in surgical technique, and the widely accepted use of surgical staplers, anastomotic failure in the form of leakage or stricture occurs at unacceptable high levels given the severe consequences. In the performance of a low anterior resection (LAR) for excision of rectal cancer, anastomotic failure has been reported to occur in up to 30% of cases. One large multicenter, observational study of 2729 patients reported a leak rate of 14.3%. These anastomotic failures cause a significant and avoidable economic burden on the healthcare system, as well as an incalculable amount of pain, suffering, and hardship for the patients in which the failure occurs. As a precaution many surgeons will tunnel a proximal segment of the bowel through the abdominal wall to form a diverting stoma. The rationale of this maneuver is to prevent the leakage of fecal matter into the abdominal cavity from a potential failure at the newly formed anastomotic site. Many times the surgeons will perform another procedure to reverse the stoma months after the initial procedure. In the same multicenter study 881 patients were given a temporary diverting stoma to mitigate the risk of an anastomotic leak, however, within this group only 128 patients developed a leak. Thus up to 85% of those patients underwent an additional surgical procedure to reverse the stoma that provided questionable benefit. The arbitrary creation of a temporary diverting stoma, and the eventual reversing procedure presents a significant and avoidable economic burden on the healthcare system, as well as exposes numerous patients to arguably unnecessary surgical risk. Presently, there is neither a clinically practical method nor device available for predicting anastomotic failure, nor objective criteria by which the operative team can decide when a diverting stoma is indicated. Our objective is to create a clinically transparent device that reduces anastomotic failures through analysis of target tissues before, during, and after creation of an anastomosis. If the tissues are deemed unsuitable for reliable formation of an anastomosis, the device alerts the operative team to take corrective action. Our approach is to design a device that: integrates into the surgical workflow by coupling to a commercially available, off-the-shelf surgical stapling instrument, employs an array of multimodality sensors to assess the viability of the tissues at the staple line, and wirelessly transmits sensor data to a base station where the real-time feedback is displayed to the operative team. Phase I of this study will focus on the evaluation of in-vivo oxygen dependent quenching of phosphorescence as the primary modality capable of assessing tissue viability, while maintaining clinical and commercial feasibility.
The proposed research is the first step to realizing a clinically transparent device capable of providing real-time assessment of anastomotic viability not currently available to the operative team;the operative team will be able to take appropriate measures to reduce anastomotic failures by ensuring adequate tissue perfusion. The proposed device will assist the operative team by objectively determining the optimal staple gap, minimizing tension across the anastomosis, and indicating when the creation of a diverting ostomy or the provision of an alternative therapy is in the best interest of the patient. The proposed device could significantly reduce patient suffering, while saving $2 billion dollars annually in excess healthcare costs.
