A Retrospective Study to Evaluate Use of Negative Pressure Wound Therapy in Patients Undergoing Bilateral Internal...

Bilateral internal thoracic artery (BITA) grafting may be associated with a higher risk of postoperative deep sternal wound infection than monolateral internal thoracic artery grafting due to a limited blood supply to the thoracic chest wall. Because preliminary studies suggest negative pressure wound therapy (NPWT) may reduce the risk of infection, a retrospective chart review of 129 patients who underwent BITA between February 2003 and October 2014 was conducted. Of those, 21 patients received NPWT for 5 days immediately following surgery and the incisions of 108 patients were covered with a conventional gauze dressing. Patient demographic and history variables as well as surgical procedure and outcome variables were abstracted. Outcome variables assessed included infection, need for transfusion, and length of hospital stay. The NPWT group was significantly younger (average age 55.9 ± 7.6 versus 60 ± 10.5 years, P = 0.049), had fewer urgent/emergent surgeries (4 [19%] versus 36 [33.3%], P = 0.247), and had significantly lower surgical risk scores (2.0 ± 2.3 versus 3.8 ± 2.8, P = 0.010). The rate of deep sternal wound infections was lower in the NPWT than in the control group, but the difference was not statistically significant (0% versus 5.6%, P = 0.336). Sternal instability was noted in 4 control patients, requiring wound re-exploration versus 0 in the NPWT group (3.7% versus 0%, P = 0.487). One (1) patient in the NPWT group had postoperative bleeding that required removal of the device. The rates of re-thoracotomy due to bleeding were 9.3% in the control compared to 4.8% in the NPWT group (P = 0.435), which translated into a greater need for blood transfusions (1.77 ± 3.4 units versus 0.3 3± 0.7 units, P = 0.056) and larger chest drainage volume (997.8 ± 710 mL versus 591.2 ± 346 mL, P = 0.012) in the control group. Hospital stay was longer in the control group, but the difference was not statistically significant (12 ± 8.8 days versus 9.4 ± 4.2 days, P = 0.184). These preliminary results are encouraging, and prospective, randomized, controlled clinical studies to compare the efficacy, effectiveness, and costeffectiveness of NPWT to other wound management modalities following cardiac surgery are warranted.