EP695 - Outcomes of Diaphragmatic Plication Following Diaphragmatic Stripping in CRS with HIPEC at the Philippine General Hospital

Purpose/Background: Diaphragmatic stripping (DS) may be performed in select cases during cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) to optimize tumor clearance. However, it is associated with postoperative respiratory complications such as pleural effusion, pneumonia, and diaphragmatic eventration. At the PGH, we have routinely performed plication to reinforce the diaphragm to avoid potential deleterious effects of DS. However, its actual impact on pulmonary outcomes remains unclear.

The study aimed to compare the incidence of postoperative respiratory complications and postoperative length of stay (LOS) between patients who underwent diaphragmatic plication (DP), and those who did not, following DS in the conduct of CRS with HIPEC.

Methods/Interventions: A retrospective review of electronic medical records was conducted on patients who underwent CRS with HIPEC at the Philippine General Hospital (PGH) between 2013 and 2025. Cases involving DS were identified, and patients were stratified based on whether DP was performed, or not. Respiratory outcomes (i.e., pleural effusion, pneumonia, eventration) were analyzed using two-sided Fisher's exact test for association. Postoperative LOS, on the other hand, was analyzed using Mann-Whitney U test (two-sided).

Results/Outcomes: Of the 193 CRS-HIPEC cases reviewed, 45 involved DS. Among these, 17 patients underwent DP, while 28 did not. Of the 28 patients who did not undergo plication, three developed diaphragmatic eventration.

For the succeeding analysis nine non-DP cases were excluded due to incomplete records, leaving 19 non-DP patients for analysis. The incidence of pleural effusion was higher in the DP group (47.1%) compared to the non-DP group (26.3%) (RR 1.79, 95% CI 0.76-4.21). Pneumonia was observed in 17.6% of patients with DP versus 5.3% in the non-DP group(RR=3.35, 95% CI: 0.38-29.37). The mean LOS did not statistically differ between groups (14.0 vs. 9.5 days, p=0.57).

Conclusion/Discussion: The wide confidence interval and relatively small sample may limit inference, and the pattern likely reflects confounding by indication. The higher complication rates observed in the DP group may reflect greater disease burden, or operative complexity, rather than an adverse effect of DP.

Diaphragmatic plication, however, remains to be a potentially beneficial adjunct in maintaining diaphragmatic integrity in cases that require extensive DS, particularly when pleural breach is encountered. Prospective studies utilizing multivariate analyses and propensity score matching are recommended to elucidate the independent impact of DP on postoperative outcomes.

Table 1. Incidence of postoperative respiratory complications and mean postoperative length of stay in patients who underwent plication after diaphragmatic stripping, and those who did not, at the Philippine General Hospital from 2013-2025.
Table 2. Relative risk (RR) of postoperative complications in patients who underwent plication after diaphragmatic stripping, and those who did not, at the Philippine General Hospital from 2013-2025.