Endourological Management of Urolithiasis in Donor Kidneys prior to Renal Transplant

Treatment of donors' asymptomatic small kidney stones and post-transplant outcomes: a meta-analysis

Kidney donors with asymptomatic small kidney stones were increasingly accepted in kidney transplantation (KT) due to organ shortage and advances in endoscopic urology. However, recipients' clinical outcomes using these donors remained unclear. We conducted a meta-analysis to summarize transplant outcomes using these donors with asymptomatic small kidney stones. Finally, 15 retrospective studies were included. The prevalence of asymptomatic small kidney stones was 5.3% (95%CI 3.5-7.8%). After transplantation, low incidence of urinary fistula (0%, 95%CI 0-1.0%), obstruction (0%, 95%CI 0-1.1%), relapse of kidney graft stone (0.3%, 95%CI 0-2.5%), and delayed graft function (0.6%, 95%CI 0-3.5%) was reported. Pooled serum creatinine was 1.3 (95%CI 1.2-1.5) mg/dl and 1.4 (95%CI 1.2-1.6) mg/dl at post-transplant 1 month and 1 year, respectively. Notably, we observed numerically higher relapse rate after conservative management (1.8% [0-9.2%] vs 0% [0-1.8%]) but numerically higher DGF rate after surgical removal of asymptomatic stones (1.8% [0-7.0%] vs 0% [0-1.9%]). Overall, short-term transplant outcomes using kidneys with asymptomatic small stones were acceptable. However, long-term transplant outcomes remained unexplored. Well-designed prospective studies are also needed to compare the efficacy of conservative management with surgical removal of "donors' gifted" asymptomatic kidney stones.

Donor kidney lithiasis and back-table endoscopy: a successful combination

INTRODUCTION

Urolithiasis in renal allografts is relatively rare with an incidence of 0.17-4.40%. It is nonetheless an important issue, as there is a risk of obstruction, sepsis and even loss of the renal allograft. The management of stones in renal allografts remains challenging because of the anatomy, the renal denervation and the use of immunosuppressive medication.

CASE PRESENTATION

This report discusses the ex-vivo treatment of asymptomatic nephrolithiasis in a living donor kidney allograft. A CT abdomen revealed a lower pole stone (5.9 × 5.5 × 5.0 mm; 920 HU) in the right kidney of the potential donor. After multidisciplinary discussion, it was decided to procure the right kidney despite the presence of a documented nephrolithiasis. After discussion with both donor and recipient, an ex-vivo flexible ureterorenoscopy for stone removal on the back table just before implantation of the allograft was planned. The stone was found in the lower pole covered by a thin film of the urothelium. The thin film of urothelium was opened with a laser and the stone fragments were retrieved with a basket. CT after one month showed no residual stones in the transplanted kidney.

CONCLUSION

Back-table endoscopy in a renal allograft is a feasible technique and should be discussed as an option in case of urolithiasis in a kidney that is considered for transplantation. Furthermore, the appropriate treatment of donor kidney lithiasis is another, although rare, method to expand the living donor renal allograft pool.

Outcomes of Renal Stone Surgery Performed Either as Predonation or Ex Vivo Bench Procedure in Renal Grafts from Living Donors: A Systematic Review

AIMS

We aimed to summarize available evidence about intraoperative and postoperative donors' and recipients' outcomes following stone surgery in renal grafts from living donors performed either before donation or as ex vivo bench surgery at the time of living-donor nephrectomy.

METHODS

A systematic review of PubMed, ISI Web of Knowledge, and Scopus databases was performed in September 2020. We included full papers that met the following criteria: original research, English language, human studies, and describing the results of stone surgery in renal grafts from living donors performed either before transplantation or as ex vivo bench surgery.

RESULTS

We identified 11 studies involving 106 patients aged between 22 and 72 years. Predonation and bench stone surgery was performed in 9 (8.5%) and 96 (90.6%) patients, respectively. Predonation stone surgery involved extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, and percutaneous nephrolithotomy in 8, 1, and 1 patient, respectively. The overall success rate of predonation stone surgery was 78%, and the complication rate was 0%. Bench stone surgery involved ureteroscopy, pyelolithotomy, or a combination of both in 79 (82.3%), 10 (10.4%), and 7 (7.3%) cases, respectively, with an overall success rate of 95.8% and an overall complication rate of 9.37%.

CONCLUSIONS

Predonation and bench stone surgery in grafts from living donors represents efficacious and safe procedures. Further studies on wider series with a longer follow-up are required.

Application of ureterorenoscope and flexible ureterorenoscope lithotripsy in removing calculus from extracorporeal living donor renal graft: a single-center experience

Here, we reported our clinical application of ureterorenoscope (URS) and flexible URS lithotripsy in stone removal on 10 cases of excised living donor kidney graft. After the extraction of donor kidney by retroperitoneal laparoscopy, the donor graft was perfused with 4 °C HCA solution. Calculus between 2–4 mm were removed intact with lithotomy forceps under direct vision of URS. Larger calculi of >4 mm were fractured with flexible URS combining holmium laser lithotripsy. Fragments of the calculus were extracted with basket extractor and lithotomy forceps. All operations were successful. The operation time was 14–31 min (average 21.2 ± 6.3 min). The kidneys were then transplanted to the recipients using routine procedure. The transplanted kidneys functioned well after transplantation. Gross hematuria resolved 1–4 d after operation (average 2.6 ± 0.9 d). The transplanted kidneys functioned well without early complications such as functional recovery delay and acute graft rejection. The donors and recipients were followed for 12 months. The size of the transplanted kidneys was normal and new stones or urinary obstruction was not seen upon urinary color Doppler ultrasound examination. In conclusion, we believe it is feasible, safe and effective to use URS or flexible URS combining holmium laser lithotripsy on extracorporeal living donor kidney.

A case of kidney transplantation using donation after circulatory death with renal calculi

Donation after circulatory death (DCD) supplies a big percentage of the organ source pool. Compared to living-related donations, donor kidneys from DCD are commonly with lower quality since they inevitably suffer from hypoxia, hypotension, and inadequate organ perfusion during the progression to circulatory arrest. The current case presents a 44-year-old male donor with wide range subarachnoid hemorrhage and multiple skull fracture from a car accident. Multiple stones were detected in his right kidney. We performed a modified ex vivo pyelolithotomy and ureteroscopy on the bench to render a stone-free allograft. We also improved the donor kidney with hypothermic/perfusion preservation machine before renal transplantation. The recipient showed no complications during the first two-month post-operational follow-up. Such a donor kidney with stones may probably be discarded by conventional perspective. Yet, the combination of the ex vivo bench-surgery technique and hypothermic oxygenation/perfusion makes it a qualified donor kidney. Thus we have demonstrated a promising way of saving borderline qualified DCD donor kidneys.