Nonsurgical Procedure Related Postoperative Complications Predicts 30 Days Perioperative Mortality, in Abdominal Surgeries. A Propensity Score Matched Analysis.

Abstract

Aims and Objectives: Our primary aim was to study association between nonsurgical techniques related complications and mortality and our secondary aim was to determine factors responsible for non surgical technique related complications. Material and Methods: All gastrointestinal and hepatobiliary procedures performed in last 3 years have been evaluated retrospectively. Nonsurgical procedure related postoperative complications were defined as perioperative complications nonrelated to surgical procedures or techniques and related to patients’ physiological health or comorbidities. To avoid selection bias in attempt to evaluate effect of non-surgical procedural related complication on mortality, we did 1:1 propensity score matching analysis with nonsurgical technique related complications as dependent factor. Propensity scores were calculated using logistic regression. Pre operative confounding factors like age, sex, American society of Anesthesia score (ASA), emergency surgery, type of surgeries like HPB surgeries, Upper gastrointestinal surgeries, small bowel surgeries, colorectal surgeries, hernia surgeries, open or laparoscopic surgeries were entered in model as covariates. We used nearest neighbor matching protocol with a calipher of 0.2. Cases were not reusable after matching. Statistical analysis was done using SPSS version 23. Results: Total 348 patients underwent various abdominal surgeries (gastrointestinal and hepatobiliary) in our department from April 2017 to March 2020. Total 24 patients developed nonsurgical technique related complications. Before Propensity score matching nonsurgical technique related complications were significantly higher in Upper Gastrointestinal surgeries (gastric and esophageal), emergency surgeries, Open surgeries, in patients who developed intraoperative hypotension, patients operated for malignancies, patients with higher ASA grades, patients in whom more blood products were used and patient who had more operative time. ASA scores independently predicted nonsurgical technique related complications. [P=0.001. Odds Ratio 3.955 (95% C.I.) 1.774-8.813)]. After Matching 24 patients patients were included in nonsurgical complication related complication group and they were compared with 23 matched controls. After matching also nonsurgical procedural related complications were significantly associated with mortality. (p< 0.0001). No intraoperative factors like intraoperative hypotension, blood product requirement, operative time predicted non-surgical technique related complication. Surgery related complications were not associated with mortality after matching. Conclusion: Nonsurgical technique related complications are associated with significant increase risk of mortality.