Thoracotomy patch repair of large diaphragmatic herniae in a porcine model: a tale of two patches.

Purpose: Congenital diaphragmatic herniae (CDH) may require patch closure in 50% of the cases. We assessed a biologic and composite mesh in a porcine CDH model.

Methods: Left sided thoracotomy was performed in 20 pigs. Approximately, 30% of the diaphragm was excised and the patch (Surgisis® or Parietex®) inserted to close this defect. The pigs were killed at 6 months and the diaphragm was harvested for biomechanical and histological assessment.

Results: The mean weight of the pigs at surgery and killing were 6.1 kg (4.2-8.4 kg) and 94.1 kg (80-131 kg), respectively. There were two recurrences and three eventrations, all with Surgisis®. There were less dense lung and abdominal adhesions in the Parietex group (P < 0.0001 and 0.025, respectively). The tensile strength of the Surgisis®, the Parietex® groups and controls were similar. There was significantly more muscle in-growth in the Parietex® patch over Surgisis® (p = 0.016).

Conclusion: Parietex® and Surgisis® patches at 6 months have a similar tensile strength to normal tissue. All recurrences and eventrations were in the Surgisis® group. Parietex® patches demonstrated more muscle in-growth into the patch compared to Surgisis®. This is the first study utilising Parietex® composite patch in the repair of large diaphragmatic defects in a porcine model.