Evaluation of closed incision management with negative pressure wound therapy (CIM): hematoma/seroma and involvement of the lymphatic system.

The objective of this porcine study was to evaluate the effect of closed incision management with negative pressure wound therapy (CIM) on hematoma/seroma formation, fluid removal into the CIM canister, and involvement of the lymphatic system. In each swine (n = 8), two sets of ventral contralateral subcutaneous dead spaces with overlying sutured incisions were created. Stable isotope-labeled nanospheres were introduced into each subcutaneous dead space. Each contralateral incision was assigned to CIM (continuous -125 mmHg negative pressure) and control (semipermeable film dressing), respectively. Following 4 days of therapy, hematoma/seroma was weighed, total fluid volume in canisters was measured, five pre-identified lymph nodes were harvested, and five key organs were biopsied. There was 25 ± 8 g (standard error [SE]) (63%) less hematoma/seroma in CIM sites compared to control sites (p = 0.002), without any fluid collection in the CIM canister. In lymph nodes, there were ∼60 μg (∼50%) more 30- and 50-nm nanospheres from CIM sites than from control sites (p = 0.04 and 0.05, respectively). There was significantly greater nanosphere incidence from CIM sites than from control sites in lungs, liver, and spleen (p < 0.05); no nanospheres were detected in kidney biopsies. Thus, in this porcine model, application of CIM significantly decreased hematoma/seroma levels without fluid collection in the canister, which may be explained by increased lymph clearance.