Anastomosis, Leaking

Despite advancements in surgical procedures, Anastomotic leakage (AL) remains a common complication following gastrointestinal surgery. It carries a high rate of morbidity and mortality, increases the cost of treatment, and leads to further interventions and delayed recovery. As surgical practice advances, AL becomes a significant obstacle for gastrointestinal surgeons worldwide (Smith et al., 2023). The rate of AL depends on the type of operation, the location of the anastomosis, the disease itself, the method of surgery, and patient-related factors. Patient factors that contribute to AL include malnutrition, diabetes mellitus, smoking, obesity, steroid use, emergency operations, and poor blood flow to tissues (Johnson and Lee, 2024). Even though AL begins with a small lesion in the area of the anastomosis, it can lead to extensive intra-abdominal sepsis, multiple organ failure, and death due to late diagnosis. Furthermore, in cases of oncological surgery, AL can negatively impact long-term outcomes because of delay in adjuvant treatment and increased recurrence (Brown et al., 2025). Early identification of AL is quite challenging because postoperative symptoms are nonspecific and may resemble the common inflammatory reaction after major surgery. Symptoms including fever, tachycardia, abdominal pain, ileus, leukocytosis, or purulent drainage usually become visible only when the condition is already at an advanced stage. Radiologic tests including contrast-enhanced CT are effective methods in identifying complications. However, using these techniques in every patient after major surgery is neither feasible nor economical, and some early cases may be overlooked (Wilson et al., 2023).

This study will evaluate the effectiveness of hyperbaric oxygen therapy (HBOT) on treating emerging indications (i.e., conditions that have shown to potentially benefit from HBOT) using the Multicenter Registry for Hyperbaric Oxygen Treatment. The study team aims to collect ongoing data on how well HBOT treats these emerging indications, and to add these data to the growing HBO Registry. The research team hypothesizes that HBOT will result in improvements of the condition of the various emerging indications.

Patients with rectal or rectosigmoid cancer undergoing radical resection will be randomly assigned to either high-tie (HT) or low-tie (LT) ligation of the Inferior Mesenteric Artery (IMA). Proximal bowel blood perfusion will be measured using Laser Speckle Contrast Imaging, and the perfusion characteristics will be compared between the two ligation groups. Additionally, for participants randomized to the LT group, an embedded prospective cohort sub-study will be performed. This sub-study involves controlled, temporary intraoperative occlusion of the preserved Left Colic Artery (LCA). During this temporary occlusion, LSCI will be used to assess the resulting changes in colonic perfusion, specifically measuring outcomes like the ischemic demarcation line (LOD) retraction distance, to further investigate the functional contribution of the preserved LCA. The overall trial aims to determine the optimal IMA ligation strategy based on objective perfusion data and a deeper understanding of LCA's role.