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.

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).

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.

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.

Lithiasis in renal graft recipients might be a dangerous condition with a potential risk of organ function impairment.

A systematic literature search was conducted through February 2023. The primary objective was to assess the incidence of lithiasis in kidney transplant (KT) recipients. The secondary objective was to assess the timing of stone formation, localization and composition of stones, possible treatment options, and the incidence of graft loss.

A total of 41 non-randomized studies comprising 699 patients met our inclusion criteria. The age at lithiasis diagnosis ranged between 29-53 years. Incidence of urolithiasis ranged from 0.1-6.3%, usually diagnosed after 12 months from KT. Most of the stones were diagnosed in the calyces or in the pelvis. Calcium oxalate composition was the most frequent. Different treatment strategies were considered, namely active surveillance, ureteroscopy, percutaneous/combined approach, or open surgery. 15.73% of patients were submitted to extracorporeal shock wave lithotripsy (ESWL), while 26.75% underwent endoscopic lithotripsy or stone extraction. 18.03% of patients underwent percutaneous nephrolithotomy whilst 3.14% to a combined approach. Surgical lithotomy was performed in 5.01% of the cases. Global stone-free rate was around 80%.

Lithiasis in kidney transplant is a rare condition usually diagnosed after one year after surgery and mostly located in the calyces and renal pelvis, more frequently of calcium oxalate composition. Each of the active treatments is associated with good results in terms of stone-free rate, thus the surgical technique should be chosen according to the patient's characteristics and surgeon preferences.

De Novo nephrolithiasis in renal transplant can have severe consequences since renal transplantation involves a single functioning kidney with medical and anatomical specificities (heterotopic transplantation on iliac vessels, immunosuppressive treatments, and comorbidities).

To systematically review all available evidence on the prevalence of de novo nephrolithiasis in renal transplant, presentation, and stone characteristics, and to report in a meta-analysis the efficacy of stone treatments (extracorporeal shock wave lithotripsy [ESWL], medical treatment, percutaneous nephrolithotomy [PCNL], open surgery, and ureteroscopy).

Medline, Embase, and the Cochrane Library were searched up to November 2021 for all relevant publications reporting the management of de novo nephrolithiasis in renal allografts. The primary outcome was stone-free rate (SFR) at 3 mo. Secondary outcomes included prevalence, stone characteristics (size, density, and composition), symptoms on presentation, need for drainage, complications, and recurrence. Data were narratively synthesized in light of methodological and clinical heterogeneity, and a meta-analysis was performed for SFR. The risk of bias of each included study was assessed.

We included 37 retrospective studies with 553 patients and 612 procedures; of the 612 procedures 20 were antegrade ureteroscopy, 154 retrograde ureteroscopy, 118 PCNL, 25 open surgery, 155 ESWL, and 140 surveillance/medical treatment. The prevalence of nephrolithiasis in renal transplant was 1.0%. The mean stone size on diagnosis was 11 mm (2-50). The overall SFR at 3 mo was 82%: 96% with open surgery, 95% with antegrade ureteroscopy, 86% with PCNL, 81% with retrograde ureteroscopy, and 75% with ESWL.

De novo nephrolithiasis in renal transplant is an infrequent condition. A high SFR were obtained with an antegrade approach (ureteroscopy, PCNL, and open approach) that should be considered in renal transplant patients owing to the heterotopic position of the renal graft. The choice of technique was correlated with stone size: generally ureteroscopy and ESWL for stones 11-12 mm (mean stone size) versus PCNL and open surgery for 17-25 mm stones.

De novo nephrolithiasis in renal transplants is an infrequent situation that can have severe consequences on the function of the renal graft. We evaluated the efficacy of each treatment and noted that antegrade approaches (open surgery, percutaneous nephrolithotomy, and antegrade ureteroscopy) were associated with the highest stone-free rate. As opposed to the management of nephrolithiasis in native kidney, an antegrade approach should be considered more in renal transplant patients.

Nephrolithiasis has been increasing over the last millennium. Although early epidemiologic studies have shown that kidney stones were two to three times more frequent in males than in females, recent reports have suggested that this rate is decreasing. In parallel a dramatic increase of nephrolithiasis has also been observed among children and adolescents. Furthermore, epidemiologic studies have shown a strong association between metabolic syndrome (Mets) traits and kidney stone disease. Patients with hypertension have a higher risk of stone formation and stone formers are predisposed to develop hypertension compared to the general population. An incidence of nephrolithiasis greater than 75% has been shown in overweight and obese patients compared to those of normal weight. It has also been reported that a previous diagnosis of diabetes mellitus increases the risk of future nephrolithiasis. Additionally, an association between metabolic syndrome and uric acid stone formation has been clearly recognized. Furthermore, 24-h urinary metabolic abnormalities have been decreasing among patients with nephrolithiasis over the last decades. Finally, nephrolithiasis could cause chronic kidney disease (CKD) and end stage renal disease (ESRD), especially in women and overweight patients. According to these observations, a better understanding of these new features among stone former patients may be required. Hence, the recognition and the correction of metabolic disorders could help not only to reduce the primary disease, but also stone recurrence.

Renal transplant lithiasis is a rather unusual disease, and the recurrence of lithiasis presents a challenging situation.

We retrospectively analyzed the medical history of one patient who suffered renal transplant lithiasis twice, reviewed the relevant literature, and summarized the characteristics of this disease.

We retrieved 29 relevant studies with an incidence of 0.34 to 3.26% for renal transplant lithiasis. The summarized incidence was 0.52%, and the recurrence rate was 0.082%. The mean interval after transplantation was 33.43 ± 56.70 mo. Most of the patients (28.90%) were asymptomatic. The management included percutaneous nephrolithotripsy (PCNL, 22.10%), ureteroscope (URS, 22.65%), extracorporeal shockwave lithotripsy (ESWL, 18.60%) and conservative treatment (17.13%). In our case, the patient suffered from renal transplant lithiasis at 6 years posttransplantation, and the lithiasis recurred 16 months later. He presented oliguria, infection or acute renal failure (ARF) during the two attacks but without pain. PCNL along with URS and holmium laser lithotripsy were performed. The patient recovered well after surgery, except for a 3 mm residual stone in the calyx after the second surgery. He had normal renal function without any symptoms and was discharged with oral anticalculus drugs and strict follow-up at the clinic. Fortunately, the calculus passed spontaneously about 1 month later.

Due to the lack of specific symptoms in the early stage, patients with renal transplant lithiasis may have delayed diagnosis and present ARF. Minimally invasive treatment is optimal, and the combined usage of two or more procedures is beneficial for patients. After surgery, taking anticalculus drugs, correcting metabolic disorders and avoiding UIT are key measures to prevent the recurrence of lithiasis.

Urinary lithiasis is one of severe postoperative complications in patients undergoing renal transplantation, possibly leading to anuria, urinary infection, or even acute renal failure. Potassium sodium hydrogen citrate (PSHC), a potassium-bearing citrate, is commonly prescribed to prevent stone formation.

A 25-year-old man (patient 1) and a 31-year-old man (patient 2) receiving renal transplantation for end-stage renal disease (ESRD) were enrolled in this study. They were given 10 g/day of PSHC granules from the ninth day to the 17th day after surgery. Patient 1 presented chest tightness, nausea, muscle weakness, and ascending paralysis on the 10th day. Patient 2 presented weak waves on EGG on the 17th day. Moreover, their serum potassium concentrations (SPCs) were 7.67 and 6.05 mmol/L, respectively.

Acute hyperkalemia.

Hemo-filtration was performed for patient 1, while patient 2 received 10% calcium gluconate 10 mL, 5% NaHCO3 125 mL, and 10% glucose 500 mL with the addition of 10 units of insulin through intravenous drip.

Their SPCs dropped to the normal range.

Physicians should pay close attentions to potential risks caused by PSHC, and monitor the SPCs to minimize the occurrence of hyperkalemia.