Triage, then what? Next steps toward reducing surgical morbidity after complex cytoreductive surgery in fit surgical patients (461)

Abstract

<b>Objectives:</b> In advanced ovarian cancer (OC), the use of a validated triage algorithm based on patient/disease factors results in significantly fewer poor outcomes, including mortality, after primary cytoreductive surgery (PCS). However, the rate of complications remains high even for triage-appropriate women, suggesting an opportunity for process improvement. To steer surgical innovation research, we sought to identify procedures that are most associated with postoperative complications in surgically fit OC patients. <b>Methods:</b> Triage-appropriate stage IIIC/IV women with OC undergoing PCS from January 2, 2012, to April 30, 2018, were identified from a prospectively maintained database. Women were considered triage- appropriate if none of the following high-risk criteria was present: <i>(i)</i> Albumin <3.5 g/dl, <i>(ii)</i> age ≥80 years, or <i>(iii)</i> age 75-79 and at least one of the following: ECOG performance status >1, stage IV disease, or complex surgery required (more than hysterectomy, salpingo- oophorectomy, and omentectomy). Characteristics were compared between patients with and without 30-day Accordion Grade 3+ complications. We calculated risk ratios (RR) using Poisson regression models with robust error variance and population attributable fractions (PAF). The PAF is defined as the reduction in the complication rate that could be expected if exposure to that specific procedure was eliminated and is a useful tool for analyzing impact and steering quality improvement. <b>Results:</b> Among 214 included women, 177 (82.7%) had intermediate/ high complexity surgery. Complete gross resection was achieved in 68.7%, and only 3.7% had residual disease >1 cm. Overall, 40 women (18.7%) experienced a grade (G) 3+ complication. The following factors were significantly associated with G3+ complications in univariate analysis: stage IV, surgical complexity, operative time, bowel resection/extent of bowel resection, and splenectomy. Additionally, operative time and bowel resection/extent of bowel resection were associated with G4+ complications (relative to none/G1/G2). Table 1 summarizes the association between specific procedures and the occurrence of a G3+ complication, and PAF analysis, adjusted for ASA score and stage. We observed that multiple bowel resections had the highest PAF (25.6; 95% CI: 4.0-47.2). Diaphragm stripping/resection and splenectomy had a PAF of 25.9 (95% CI:-3.8-55.6) and 12.1 (95% CI: -4.8-29.0), respectively, though not statistically significant. <b>Conclusions:</b> Bowel resection, diaphragm procedures, and splenectomy are essential to successful PCS in OC. Each is a potential source of significant complications, even after triage, to eliminate high-risk patient factors. For example, 25% of all G3+ complications occur in patients with multiple bowel resections. Focusing our surgical improvement research on these procedures will likely have the highest yield in further reducing morbidity associated with cytoreductive surgery for our patients.