Subcutaneous Depth in Kidney Transplantation: Indication for Negative Pressure Wound Vacuum Therapy?

Purpose: Wound complications after kidney transplant (KTx) consume valuable resources, including prolonged hospital stays and increased costs. Risk factors include immunosuppression exposure, diabetes, and obesity as indexed by body mass index (BMI). However, BMI is not an accurate surrogate of body habitus. In this study, we sought to determine the effect of subcutaneous depth (SQD) on KTx outcomes, specifically wound complications. Methods: We measured SQD in 97 KTx only (79 cadaveric;18 living donor) only over 18 months. The mean age of the recipients (56M:41F) was 48 years, with an average BMI 27.8. SQD was measured from the midpoint of the lateral portion of the incision and measured the distance from the fascia to the skin edge, to the closest 0.5cm.. Data analyzed included presence of diabetes, hypertension, PRA, pretransplant dialysis, prior transplant, and induction therapy. Post transplant complications analyzed included wound infection, dehiscence, lymphocele, renal artery thrombosis/stenosis, urine leak, ureteral stenosis and need for vacuum assisted closure therapy. Results: The average SQD of our recipients was 2.9cm. Patients with a SQD > 2.5cm were more likely to require wound vac therapy (average length of therapy, 46.6 days) compared to those with a SQD25, SQD > 2.5cm was still associated with a higher likelihood of requiring a wound vac (odds ratio 3.4). Conclusions: In summary, SQD > 2.5cm is an independent risk factor for requiring negative pressure vacuum therapy. This is a simple intraoperative identifier which should stratify those at risk for later intervention.