S1811 Risk Factors of Prolonged Bowel Dysfunction after Hyperthermic Intraperitoneal Chemotherapy and Cytoreductive Surgery for the Treatment of Metastatic Tumors of the Abdomen and Pelvis

Introduction: Hyperthermic intraperitoneal chemotherapy (HIPEC) with cytoreductive surgery (CRS) is used to treat metastatic tumors of the abdomen and pelvis. The treatment is known to cause prolonged ileus and pseudo-obstruction. Risk factors of small bowel dysmotility after HIPEC and CRS are not well known. Methods: A retrospective review of an IRB-approved database was conducted. We evaluated all patients who had HIPEC and CRS for metastatic colon and appendiceal cancer and mesothelioma from 2016-2023. We sub classified patients with a high or low peritoneal tumor burden by a validated peritoneal cancer index (PCI). Ileus and PSBO were diagnosed by abdominal imaging. NGT removal post op., use of TPN, enteral tubes, prokinetics and opioids was analyzed. Comparisons of categorical and continuous covariables were conducted using Fisher’s exact test and the Wilcoxon rank sum test, respectively. Predictors with P-values < 0.1 and sufficient data points were further analyzed by univariate and multivariate logistic regression analysis. Results: 195 patients met the study criteria. PCI was available for 158 patients. There was no significant difference in the demographics of the low PCI (range 1-14, n: 54) and high PCI (range 15-29, n: 96) groups. There was a significantly higher bowel recovery time in the high PCI than low PCI group (median : 11.5 days vs 9 days), P = 0.027. Patients with persistent bowel dysfunction at day 30 were 7.47 times more likely to have malnutrition P = 0.001. TPN use at day 30 was associated with malnutrition (OR =3.58, 95%CI (1.27, 10.12), P = 0.016). TPN use was 2.63 times more likely in patients with bowel dysfunction at 30-day, P = 0.024). Persistent bowel dysfunction was 6.95 times more likely linked to a venting G tube P = 0.032). TPN users were 11.51 times more likely to have a venting G tube (OR =11.51, 95%CI (1.1, 120.69), P = 0.042). A h/o radiation therapy was 12.25 times more likely with bowel dysfunction complications (OR =12.25, 95%CI (1.5, 99.83), P = 0.019). The use of mu receptor antagonist was only seen in 2 patients (Table 1). Conclusion: This study identified statistically significant risk factors for prolonged post op bowel dysfunction after HIPEC and CRS. A high PCI score, malnutrition and use of TPN for 30 days, a history of pelvic radiation therapy were statistically significant risk factors. The use of peripherally acting mu receptor antagonists was rare. Table 1. - Predictive factors for 5 outcome variables assessed by univariate and multivariate logistic regression analysis Univariate Analysis Multivariate Analysis Predictors OR 95% CI P-value OR 95% CI P-value Post-Op Bowel functioning (30 days) Persistent SBO 3.49 (1.33,9.14) 0.011 2.95 (1.02,8.52) 0.046 TPN 3.38 (1.53,7.46) 0.003 2.63 (1.14,6.07) 0.024 TPN Duration (days) 1.00 (0.99,1.01) 0.508 Malnutrition Opioid use History 2.93 (1.31,6.52) 0.009 2.00 (0.78,5.13) 0.148 Abnormal CT scan at Dx 2.62 (1.15,5.96) 0.022 1.87 (0.68,5.14) 0.228 Persistent SBO 7.74 (2.85,21.00) < .0001 7.47 (2.24,24.89) 0.001 NPO Duration (days) 1.13 (1.03,1.23) 0.011 1.02 (0.92,1.13) 0.700 TPN 6.20 (2.67,14.36) < .0001 3.58 (1.27,10.12) 0.016 TPN Duration (days) 1.01 (0.99,1.03) 0.238 Bowel dysfunction BMI 0.89 (0.79,1.01) 0.066 0.83 (0.72,0.97) 0.019 Opioid use History 4.14 (1.07,16.02) 0.039 2.99 (0.6,14.86) 0.180 Radiation Abd Pelvis 6.94 (1.49,32.46) 0.014 12.25 (1.5,99.83) 0.019 Abnormal CT scan at Dx 4.71 (1.40,15.93) 0.013 3.67 (0.81,16.52) 0.091 NPO Duration (days) 1.11 (1.01,1.22) 0.025 1.03 (0.91,1.17) 0.623 TPN 11.13 (2.33,53.12) 0.003 9.70 (1.46,64.52) 0.019 TPN Duration (days) 1.00 (1.00,1.01) 0.309 Feeding Tube Duration (days) 1.02 (0.95,1.09) 0.585 Venting G Tube Persistent SBO 16.83 (3.36,84.40) 0.001 6.95 (1.19,40.64) 0.032 NPO Duration (days) 1.12 (1.01,1.23) 0.033 1.01 (0.88,1.15) 0.930 TPN 19.75 (2.33,167.73) 0.006 11.51 (1.1,120.69) 0.042 Note: SBO: Small Bowel Obstruction, NPO means "nothing by mouth", TPN: Total Parental Nutrition.