Transplantation of the Horseshoe Kidneys: A Model for Dual Adult Kidney Transplantation

Abstract

Background: The shortage of organs has called for the use of two marginal adult kidneys (MAKs) with a low nephron mass as dual adult kidneys transplanted to a single recipient. The operative techniques of the transplantation of these kidneys are still debated. Since the horseshoe kidneys have been transplanted as early as 1975, it is theorized that the technique of the en bloc transplantation of the horseshoe kidney may be applied to the MAKs. Material and Methods: The world literature search during the period 1975–2021 on the use of deceased-donor horseshoe kidneys was reviewed. The selection of the donors, the anatomy of the kidneys, the principles of organ recovery, the transplantation procedure, and the results were discussed. Finally, this technique of en bloc transplantation was applied successfully to seven pairs of MAKs and is described herein. The dual adult kidneys were simultaneously vascularized by the donor aorta and vena cava, which were anastomosed, respectively, to the recipient iliac artery and vein. Results: A total of 131 case reports of deceased horseshoe kidney donors were reviewed, of which 53 en bloc kidneys were transplanted successfully to a single recipient, and the remaining 78 were divided and transplanted as single units to 131 recipients. Twenty-five single kidneys were discarded. At the time of publication, all horseshoe kidneys had a good renal function. In the series of seven pairs of MAKs transplanted en bloc, the operative time was 3 h. There were no primary nonfunctions, no vascular thromboses, no urinary leakages, and no wound infections. Only two patients required temporary dialysis despite an average of 28.4 h of cold ischemia time. No hydronephrosis and lymphocele was experienced. Both patient and graft survival were 100%. At the time of follow-up at 36 months, serum creatinine levels averaged 1.8 mg/dL (range 1.4–1.9). Conclusions: This technique of en bloc renal transplantation using the donor aorta and vena cava for revascularization can be applied to both the horseshoe kidneys and the MAK, and improve organ utilization.