The introduction of calcineurin inhibitors (CNIs) has significantly improved the outcome of solid organ transplantation. However, CNIs have been associated with nephrotoxicity and other side-effects . One alternative to CNIs is a new class of immunosuppressants, sirolimus (SRL) and everolimus (EVL) that inhibit the mammalian target of rapamycin (mTOR inhibitors). Quite early after the introduction of mTOR inhibitors into immunosuppressive regimens, it became apparent that the antiproliferative actions of mTOR inhibitors might have an effect on healing as evident by poor wound healing and the occurrence of lymphoceles after renal transplantation [2–4]. This antiproliferative effect on fibroblasts in the healing wound is likely to be the explanation for complications of healing . In particular, tracheal dehiscence was noted after lung transplantation .
In 2006, a Cochrane review by Webster et al.  evaluated the efficacy and safety of mTOR inhibitors for kidney transplant recipients in the immediate post-transplant period. The authors found that patients treated with mTOR inhibitors showed an increased risk of developing lymphoceles when compared with patients treated with CNIs or antimetabolites. They did not find an increased risk for developing wound complications nor did they find a difference when comparing lower versus higher dose mTOR inhibitors or when comparing lower dose mTOR inhibitors plus standard CNIs versus higher dose mTOR inhibitors plus lower dose CNIs. Their literature search was done up to July 2005 and since then some of the included conference abstracts have been published as full articles and a number of additional, large RCTs have been published that report on wound complications or lymphoceles.
Therefore, the primary aim of the study was to evaluate the occurrence of wound complications and lymphoceles in solid organ transplant recipients receiving mTOR inhibitors from the time of transplantation compared with patients not receiving mTOR inhibitors. We tested the null hypothesis that wound complications and lymphoceles do not occur more commonly in patients receiving mTOR inhibitors than in patients who do not receive mTOR inhibitors.
As it has been suggested that steroid avoidance may reduce the negative impact of mTOR inhibitors on wound healing and lymphocele formation, a secondary analysis was planned to review the effects of mTOR inhibitors plus steroids versus mTOR inhibitors without steroids on these outcomes [8,9].