Percutaneous nephrolithotomy for adult renal transplant de novo graft lithiasis: a single center analysis and systematic review of the literature.

INTRODUCTION/OBJECTIVE: Graft stones in renal transplant recipients pose a unique challenge, finding effective interventions to ensure optimal graft function and patient well-being. Various methods of stone clearance have been described for graft stones, including percutaneous nephrolithotomy (PCNL). While PCNL is a promising approach for managing graft stones, specific outcomes and associated characteristics for this approach have not been comprehensively evaluated before. This study aims to evaluate the safety and efficacy of the use of PCNL as the primary intervention of graft stones by assessing stone-free rates (SFR), treatment impact on graft function, and perioperative complications.

METHODS: A retrospective clinical audit was performed for all transplants performed in a single center from 2007 to 2022, which included all graft lithiasis patients who were treated with PCNL. Both perioperative parameters and post-operative outcomes were collected. In addition, a systematic review including articles from MEDLINE, Embase, Web of Science yielded 18 full-text articles published between 1/1/2000 and 15/11/2023. The results pertaining to patients who underwent PCNLs for graft stones were cross-referenced and thoroughly evaluated. The review encompassed a comprehensive analysis of clinical data, postoperative outcomes, and procedural details. The protocol for the systematic review was prospectively registered on PROSPERO (CRD42023486825).

RESULTS: In our center, 6 graft lithiasis patients were treated with PCNL. The initial SFR was 83.3%. SFR at 3 months and 1 year were both 100.0%. SFR at 3 years was 66.7%. Other centers reported initial SFR of 82.6-100.0% (interquartile range). SFR at 3 months, 1 year, 3 years was not well reported across the included studies. Incidence of graft lithiasis ranged from 0.44%-2.41%. Most common presentations at diagnosis were oliguria/anuria/acute kidney injury and asymptomatic. Reported complications included blood loss, transient hematuria, high urine output, sepsis, and damage to surrounding structures. The most commonly reported metabolic abnormalities in transplant lithiasis patients included hyperuricemia and hyperparathyroidism.

CONCLUSION: PCNL is a practical and efficient choice for addressing graft lithiasis, demonstrating excellent stone clearance and minimal perioperative complications. These findings show the importance of PCNL as a primary intervention in this complex patient population.