Calculi complicating a renal transplant

Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis

AIM

To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients.

METHODS

A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones.

RESULTS

Twenty one studies with 64416 kidney transplant patients were included in the analyses to assess the incidence of kidney stones after kidney transplantation. The estimated incidence of kidney stones was 1.0% (95%CI: 0.6%-1.4%). The mean duration to diagnosis of kidney stones after kidney transplantation was 28 ± 22 mo. The mean age of patients with kidney stones was 42 ± 7 years. Within reported studies, approximately 50% of kidney transplant recipients with kidney stones were males. 67% of kidney stones were calcium-based stones (30% mixed CaOx/CaP, 27%CaOx and 10%CaP), followed by struvite stones (20%) and uric acid stones (13%).

CONCLUSION

The estimated incidence of kidney stones in patients after kidney transplantation is 1.0%. Although calcium based stones are the most common kidney stones after transplantation, struvite stones (also known as “infection stones”) are not uncommon in kidney transplant recipients. These findings may impact the prevention and clinical management of kidney stones after kidney transplantation.

Renal transplantation in cats with calcium oxalate urolithiasis: 19 cases (1997–2004)

OBJECTIVE

To determine outcome of renal transplantation in cats with renal failure associated with calcium oxalate urolithiasis.

DESIGN

Retrospective case series.

ANIMALS

19 cats.

PROCEDURE

Medical records were reviewed for evaluation of signalment, preoperative clinical signs, physical examination results, dietary history, clinicopathologic data, abdominal imaging, postoperative diet, complications, and long-term outcome.

RESULTS

The domestic shorthair was the most common breed represented. There were 13 spayed females and 7 castrated males. Mean age was 6.8 years. Clinical signs included weight loss, lethargy, vomiting, anorexia, polyuria, and polydipsia. Before surgery, cats received commercially available canned or dry food (n = 10), a prescription renal failure diet (5), a commercial diet to manage struvite crystalluria (1), or an unknown diet (3). Seventeen cats were anemic. All cats were azotemic. Hypercalcemia was detected in 7 cats. Abdominal imaging revealed nephrolithiasis, ureterolithiasis, or both in all cats. Median duration of survival of all cats was 605 days. Eight cats were alive 282 to 2,005 days (median, 1,305 days) after surgery. Eleven cats died 2 to 1,197 days (median, 300 days) after surgery. Five cats formed calculi in their allograft (120 to 665 days). Two of the 5 cats that formed calculi were hypercalcemic. Four of the 5 cats died following complications associated with formation of calculi.

CONCLUSIONS AND CLINICAL RELEVANCE

Renal transplantation appears to be a viable option for cats in renal failure secondary to calcium oxalate urolithiasis. In addition to reported complications in renal transplant recipients, formation of calculi within the allograft may also occur.

Urinary stones following renal transplantation

BACKGROUND

The formation of urinary tract stones following renal transplantation is a rare complication. The clinical features of stones after transplantation differ from those of non-transplant patients. Renal colic or pain is usually absent and rarely resembles acute rejection.

METHODS

We retrospectively studied 849 consecutive kidney transplant patients in The Rogosin Institute/The Weill-Cornell Medical Center, New York who were transplanted between 1980 and 1997 and had functioning grafts for more than 3 months, to determine the incidence of stone formation, composition, risk factors and patient outcome.

RESULTS

At our center, urinary stones were diagnosed in 15 patients (1.8%) of 849 functioning renal grafts for 3 or more months. Of the 15 patients, 10 were males and 5 were females in their third and fourth decade. Eight patients received their transplant from living donors and 7 from cadaveric donors. The stones were first diagnosed between 3 and 109 months after transplantation (mean 17.8 months) and 5 patients had recurrent episodes. The stones were located in the bladder in 11 cases (73.3%), transplanted kidney in 3 cases and in multiple sites in one case. The size of stones varied from 3.4 mm to 40 mm (mean 12 mm). The composition of stones was a mixed form of calcium oxalate and calcium phosphate in 5 cases and 4 patients had infected stones consisting of struvite or mixed form of struvite and calcium phosphate. Factors predisposing to stone formation included tertiary hyperparathyroidism (n = 8), hypercalciuria (n = 5), recurrent urinary tract infection (n = 5), hypocitraturia (n = 4), and obstructive uropathy (n = 2). Many cases had more than one risk factor. Clinically, painless hematuria was observed in 6 patients and dysuria without bacteriuria in 5 patients. None had renal colic or severe pain at any time. There were no changes in graft function at diagnosis and after removal of stones. Five patients passed stones spontaneously and 8 patients underwent cystoscopy for stone removal.

CONCLUSION

Urinary stone formation following kidney transplantation is a rare complication (1.8%). Hyperparathyroidism, hypercalciuria, recurrent urinary tract infection and hypocitraturia are the most common risk factors, but often there are multiple factors which predispose to stone formation. To detect stones and determine their location and size, ultrasonography appears to be the most useful diagnostic tool. Prompt diagnosis, the removal of stones and stone-preventive measures can prevent adverse effects on renal graft outcome.

Urolithiasis in renal and combined pancreas/renal transplant recipients

PURPOSE

Urological complications in renal transplant recipients will become more common with increasing numbers of transplantations as well as increased graft survival secondary to improvements in immunosuppression. Urinary stone disease may be one of those complications. We determine the current incidence of urinary stone disease in renal transplant patients based on contemporary immunosuppressive regimens.

MATERIALS AND METHODS

We reviewed the records of 1,730 renal and 83 pancreas/renal transplantations performed during the cyclosporine era and identified 8 recipients (0.4%) with urinary stone disease, including 3 with renal pelvic stones, 1 with multiple ureteral stones and 4 with bladder calculi.

RESULTS

Treatment ranged from conservative observation to open pyelolithotomy, and included percutaneous nephrolithotomy and extracorporeal shock wave lithotripsy. The ureteral stones were removed with antegrade and retrograde ureteroscopy. The 4 bladder stones were treated with cystolithalopaxy. No case had significant permanent graft damage. Mean followup was 68.6 months. Mean serum creatinine was 1.5 mg./dl. (normal 0.5 to 1.3) at baseline and 2.38 after followup.

CONCLUSIONS

While the incidence of upper tract urinary stone disease in renal (0.23%) and pancreas/renal (1.2%) transplant recipients is not statistically significant (p <0.45), the latter have significantly higher rates of bladder stones (4.8 versus 0%, p <0.001). The diagnosis of urinary stone disease in transplant recipients can be challenging because of the lack of symptoms but the treatment approach is the same as in the normal population.

A case study with delayed renal graft function as a consequence of severe secondary hyperparathyroidism

A 36-year-old Arab man had been treated with hemodialysis for 6 years. During that time he received no treatment with phosphate binders or 1,25-dihydroxy-vitamin D3. He thus developed a severe form of secondary hyperparathyroidism and presented with bone disease, pseudoclubbing of the fingers, and soft-tissue calcification. He was transplanted with a kidney from a living donor, but there was no immediate onset in renal function. A biopsy showed crystal deposition that was thought to be due to his secondary hyperparathyroidism. Four weeks after the renal transplantation with still no evidence of a functioning graft, a parathyroidectomy was performed. A few days later, graft function recovered, and the amount of the crystals in the kidney decreased. There is strong evidence that the severe secondary hyperparathyroidism prevented the onset of renal function. It is concluded that crystal deposition with graft dysfunction should be an absolute indication for parathyroidectomy.

Extracorporeal shock-wave lithotripsy in transplanted kidney

Urolithiasis is the least described urologic sequela of renal transplantation. We describe a renal transplant patient who presented with painless gross hematuria. An intravenous pyelogram demonstrated a 4 x 7-mm calculi in the region of the ureteropelvic junction, causing moderate hydronephrosis. The patient was treated successfully with extracorporeal shock-wave lithotripsy (ESWL). Serum creatinine and twenty-four-hour creatinine clearance were unchanged from levels prior to ESWL.

Percutaneous nephrolithotomy in transplanted kidney

Renal transplant patients with urologic complications can be managed safely with percutaneous techniques. The development of renal calculi in transplanted kidneys is uncommon, but in these cases complications such as infection and urinary tract obstruction with impairment of graft function can occur. We report 2 cases managed successfully with percutaneous nephrolithotomy.

Treatment of renal transplant stones by extracorporeal shock-wave lithotripsy in the prone position

Two patients with renal transplant lithiasis were successfully treated with extracorporeal shock-wave lithotripsy (ESWL) in the prone position. Pathogenesis and treatment of transplant lithiasis are discussed. Performing ESWL on renal transplant patients in the prone position has advantages over standard positioning techniques.

Percutaneous stone and stent removal from renal transplants

Techniques developed for removal of stones from normally sited kidneys can be safely employed in the transplanted kidney. We describe our experience in removing stones, stent material and organised blood clot from renal transplant collecting systems, using modified percutaneous techniques.

Extracorporeal shock wave lithotripsy in a renal transplant patient

We report a case of nephrolithiasis in a transplanted kidney that was treated successfully with extracorporeal shock wave lithotripsy. The patient experienced transient partial obstruction after lithotripsy and, thus, intense monitoring of the transplant patient is necessary.

Current operative management of urinary calculi after renal transplantation

We examined the medical records of renal transplantation patients at our institution to determine the incidence and etiology of renal calculi after renal transplantation. Of 7 patients identified calculi formed on the basis of congenital hyperoxaluria in 2, secondary to chronic urinary infection in 1 and from iatrogenic causes in 4. We review the various surgical and radiological procedures used to treat these renal transplant patients. We also discuss the role of the new treatment modalities in managing urolithiasis in transplant recipients.

Lithiasic complications of renal transplantation: the donor graft lithiasis concept

Lithiasis is usually a late complication of renal transplantation reported in approximately 1% of all renal allografts. Underlying predisposing conditions for the formation of calculi are present in almost all cases. Preexisting stones in the donor kidney have been reported once previously. The authors have observed 2 such cases, detected by routine sonography. In 1 case, stone migration into the ureter led to acute postoperative transplant failure; this complication has been reported previously.

The percutaneous removal of calculi from transplanted kidneys

Renal calculi complicating transplanted kidneys are uncommon but they can be an important cause of deterioration in graft function. We report 2 complicated cases managed by percutaneous nephrostolithotomy.

Stones in renal transplants

In a 50-year-old man (case 1) and a 17-year-old girl (case 2) stones developed in a functioning renal transplant. The respective intervals from transplantation to appearance of stone were seven years and six months. The serum calcium was elevated to approximately 3.00 mmol/l in case 1 and 2.65 mmol/l in case 2. The concentration of parathyroid hormone in serum was increased in case 1. Subtotal parathyroidectomy was performed in both patients, with removal of 2550 mg (case 1) and 150-160 mg (case 2) parathyroid tissue. In case 2 slight hypercalcaemia reappeared two months later. When stones in a transplanted kidney are associated with only slight hypercalcaemia and there is no deterioration of the renal function, conservative measures to reduce the serum calcium should be tried before subtotal parathyroidectomy is undertaken.

Urolithiasis after kidney transplantation--clinical and mineralogical aspects

Urolithiasis is a rare complication following kidney transplantation. Experience with this complication in 6 of 426 transplantations performed from 1968 to 1979 is reviewed. The clinical symptoms are different from the disease in non-transplant patients. Three major predisposing causes for the development of calculi after kidney transplantation were found in our patients--urodynamic disorders following complications of the ureterovesical anastomosis, persistent bacteriuria and renal tubular acidosis and, less importantly, the presence of hypercalcemia and hypercalciuria as a result of secondary hyperparathyroidism. Crystal-optical and x-ray-diffraction studies contributed to the interpretation of the constituents and texture of the calculi and of the aetiological factors concerned.

Urinary tract calculous disease after renal transplantation

We report 3 cases of a series of 372 (0.8 per cent) renal transplant recipients in whom urinary tract calculi developed as a complication of the procedure. In each patient symptoms were minimal and not classic of calculous disease. We disagree with the contention that all such patients have either hypercalcemia, infection, or tubular acidosis, although thorough evaluation is indicated. We believe this entity should be considered in problematic renal transplantation patients. Conservative therapy is advocated when the situation permits.

Calculi in renal transplants

Three patients who underwent live donor renal transplantation subsequently developed calculi in their allografts. Hypercalcaemia and secondary hyperparathyroidism were present in 2 cases and these were treated by subtotal parathyroidectomy. Urinary stagnation and infection were contributory factors in the third case and reimplantation of the ureter was necessary. In all patients no further calculi have developed following treatment and allograft function remains satisfactory.

Kidney stones and renal transplantation

Only 10 cases of renal calculi in transplanted kidneys are reported in the literature. Etiology is not uniform in all the cases. Some of these cases were managed conservatively. We herein report a case in which the etiology of the stone may be urinary tract infection. This patient was managed conservatively.

Pyelolithotomy of a renal transplant

A large calculus developed in a renal transplant patient and was removed by pyelolithotomy. Hyperparathyroidism was not present. Important factors to consider before performing a nephrolithotomy in a transplanted kidney are whether the transplant was a right or left kidney and the timing of the operation in relation to renal function and infection. The etiology for renal stone formation in renal transplant recipients includes hyercalciuria, renal tubular acidosis, antacid administration and infection.

Idiopathic ureterolithiasis in a renal transplant patient

Only 9 cases of ureteral stone formation in renal transplant recipients have been reported previously. The majority of these occurred in association with hyperparathyroidism. We herein describe a case in which a ureteral calculus caused partial obstruction within 3 months in a euparathyroid recipient of a living related renal transplant.

Nephrolithiasis and nephrocalcinosis after renal transplantation: a case report and review of the literature

Stone formation in renal allografts is rare. Although infection or renal tubular acidosis can predispose to calcium deposition in a renal allograft, hyperparathyroidism is usually an accompanying factor. Parathyroidectomy is recommended as the treatment of choice when stone deposition or nephrocalcinosis occurs after transplantation. The reported case demonstrates that aggressive therapy is also necessary to eliminate calculi from the urinary system to avoid mechanical obstruction, continued infection or renal paraenchymal damage.