Peritransplant management of retained native kidneys in autosomal dominant polycystic kidney disease.

As with other forms of end-stage kidney disease, transplantation is the treatment of choice for patients with autosomal dominant polycystic kidney disease (ADPKD) [1]. Transplantation is both life-extending and provides a superior quality of life for those patients who reach the need for renal replacement therapy. Most transplant centers proceed with transplantation either from a living donor or from a deceased donor without removal of the native polycystic kidneys since in most patients these kidneys are asymptomatic and removal pretransplant entails additional surgery with finite complications [2]. Bilateral nephrectomies done simultaneously with the transplant extend the procedure and introduce potential complications that presumably would not occur in patients undergoing standard transplants [3]. The major indications for nephrectomy of polycystic kidneys prior to the transplant are shown in Table 1. Many patients complain about abdominal pain related to their autosomal dominant polycystic kidneys and if this pain is refractory to medical management, it could be an additional indication for native kidney removal [4]. It is actually unusual for patients after the transplant to require nephrectomies for complications related to their native kidneys (<20% in my experience). Also, there is evidence that the size of the kidney stabilizes and perhaps even regresses after a successful transplant, particularly with mTOR inhibitors used as immunosuppression [5]. The major advantages of polycystic kidneys left in situ are the maintenance of urine output that make the fluid restrictions on dialysis easier to handle and the kidney’s ability to produce erythropoietin and thus maintain hemoglobin values higher than other patients with chronic renal disease. In the absence of a major indication for nephrectomy, the major argument favoring this procedure is the potential need for post-transplant nephrectomy that involves major surgery in an immunosuppressed patient. However, this risk is mitigated by having a patient with normal renal function which avoids the inherent risk of operating on a patient with end-stage renal disease. The standard approach to removing polycystic kidneys has been by a separate operation prior to transplantation. For living donor recipients, this can be staged so that when the patient recovers from the nephrectomy surgery there is only a short-time dialysis requirement in the anephric state. For a deceased donor recipient, pretransplant nephrectomy does provide a hardship since the patient must be maintained on dialysis until a suitable donor is identified thus having to endure severe restrictions on fluid intake. A paper in the current issue of Nephrology Dialysis Transplantation contains a large experience with ipsilateral nephrectomy at the time of renal transplant [6]. This series is unique in that the procedure was done whether or not an indication for a nephrectomy existed. In these authors’ experienced hands, the procedure is relatively safe and did not impair graft or patient survival. However, since there are no concomitant controls, the paper raises many questions in regard to patient management. Obviously, since the ipsilateral nephrectomy was done in some cases without specific indications, it is possible that the extra surgery by adding anesthesia and prolonged cold ischemia could cause inferior long-term transplant results. Although the mean weight of the removed kidneys was substantial, some kidneys as small as 500 g were removed making the indication for the extra operation more questionable. If the indication for nephrectomy is a chronic infection, it seems hard to justify leaving one kidney in place. Likewise, if the indication for nephrectomy is a massive enlargement of the kidneys producing symptoms, it would be very difficult to know which kidney has to be removed before the transplant was actually performed. Bilateral nephrectomy is not a simple operation and even in the hands of this experienced group neither is ipsilateral nephrectomy. The complication rate of 12% requiring reoperation is not trivial and is additive to the potential surgical complications of the transplant procedure itself. The remaining polycystic kidney after transplantation is another obvious drawback to this procedure. In the series, the contralateral kidney was already removed from the patient prior to the transplant in 22 patients. Another 20 patients had this done after the transplant, 2 at retransplantation. The timing was anywhere from 5 to 153 months. However, 57 patients still had their contralateral kidney in place. Thus, the argument that the number of surgical procedures would be reduced by the simultaneous ipsilateral transplant and nephrectomy is only true if the patient is left alone. Clearly, a major concern for any type of nephrectomy operation is to do it safely without