Significance of diaphragmatic resections and thoracic chemoperfusion on outcomes of peritoneal surface disease treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

Background: Diaphragmatic resection (DR) during CRS/HIPEC exposes the thoracic cavity to direct contamination from the peritoneal cavity. The effect of thoracic chemoperfusion in combination with HIPEC in these patients is unknown.

Methods: A prospective database of 1,077 procedures was analyzed. Type of malignancy, thoracic perfusion, resection status, comorbidities, morbidity, mortality, and overall survival were reviewed.

Results: DR was a component of 102 CRS/HIPEC procedures performed for 57 (55.9 %) appendiceal and 22 (21.6 %) colon primary lesions. DR was associated with higher volume of disease as evidenced by more organ resections (3.7 vs. 2.8, p < 0.001) and increased rates of incomplete cytoreduction (67 vs. 52 %, p = 0.004). Patients with and without DR had similar 30-day major morbidity (23.5 vs. 16.8 %, p = 0.1) and worse 90-day mortality (12.8 % vs. 6.12 %, p = 0.03), respectively. Multivariate analysis showed DR (p = 0.01) and diabetes (p = 0.005) to be associated with worse mortality. Nineteen (20 %) DR patients underwent synchronous abdominal and thoracic chemoperfusion. Intrathoracic recurrence following DR with thoracic perfusion was 17 % (3/18) vs. 2.3 % (2/85) without perfusion (p = 0.04). Median survival following complete cytoreduction was similar for patients with low-grade appendiceal (LGA) (not reached with DR and 175 months without DR, p = 0.17) and colorectal cancer (23 months with and 31 months without DR, p = 0.76).

Conclusions: Diaphragmatic resection during CRS/HIPEC is an independent predictor of surgical mortality. Intrapleural perfusion was associated with more thoracic recurrence; however, complete cytoreduction with or without DR can achieve similar survival for patients with LGA and colorectal primary lesions. DR should be performed only if careful inspection deems all peritoneal disease resectable.