Long term survival and perioperative propensity score matched outcomes of diaphragmatic resections compared to stripping in cytoreductive surgery + intra-peritoneal chemotherapy.

OBJECTIVES: To assess the impact of short and long term outcomes of diaphragm resection and repair in cyto-reductive surgery (CRS) and intra-peritoneal chemotherapy (IPC).

METHODS: 1230 consecutive CRS/IPC procedures were performed between 1996 and 2018 in Sydney, Australia. Among these, 652 underwent diaphragmatic intervention. The analysis was preformed according to histological subtype. First diaphragm interventions were compared to non-diaphragmatic CRS. Secondly, diaphragm resection was compared to diaphragm stripping. Overall survival and recurrence free survival was assessed based on histological diagnosis.

RESULTS: There were no differences between the resection and stripping groups for the colorectal cohort. For mesothelioma, increased incidences of pleural effusions in the resection group were noted (63% vs.28%, p = 0.017). In HAMNs, the resection group was associated with increased reoperations (42% vs. 15%, p = 0.03) and in hospital death (16.7% vs. 0.6%, p = 0.012). Resection in LAMNs were linked with increased transfusion requirements (9 vs. 6, p = 0.01), reoperation (39% vs. 23%, p = 0.05) and prolonged length of stay (34 days vs. 25 days, p = 0.02). There were no differences in overall survival and recurrence free survival in colorectal cancer. Median overall survival was decreased in mesothelioma by 20 months. In LAMNs the median survival was significantly decreased for the resection group. Similarly, the resection group had a 4-month earlier recurrence.

CONCLUSION: We conclude that diaphragm interventions are an essential part of CRS. They are associated with increased perioperative morbidity. This morbidity is not attributable to whether the patient underwent diaphragm stripping or resection. However in mesothelioma and LAMNs, requiring diaphragm resection is likely to be an indicator for tumor aggression.