EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Renal transplant is the preferred treatment for patients with end-stage renal disease (ESRD). There are several possible postoperative renal transplant complications, including urine leak, ureteral stricture, vesicoureteral reflux, hematuria, urinary tract infections, and vascular complications.¹ Ureteral obstruction is the most common cause of urinary complications.¹ Ureteral stricture has been found to be associated with decreased death of censored graft survival.^2,3

The management of ureteral strictures consists of minimally invasive techniques and open surgical procedures based on the level of complexity.4 Herein, we report a case of ureterocalicostomy, using the native ureter in a patient with extensive allograft ureteral stricture after renal transplant.

Informed consent was obtained from the described patient. A 20-year-old female patient with ESRD due to glomerulonephritis underwent deceased donor renal transplant. Two months after transplant, she presented with oliguria, nausea, and vomiting. The patient had no history of fever, gross hematuria, graft surgery site pain, or malaise. The immunosup-pressive regimen consisted of tacrolimus, mycop-henolate mofetil, and prednisolone.

Physical examination showed that vital signs were stable with no abdominal or graft site tenderness, but edema was present in the lower extremities.

The laboratory data showed elevated serum creatinine (7.4 mg/dL). The abdominopelvic sonography showed severe pelvocaliectasis (hydronephrosis) of the transplanted kidney without ureteral dilatation. Due to severe hydronephrosis and elevated serum creatinine, a 6F percutaneous nephrostomy tube was placed into the grafted kidney, guided by sonography. After nephrostomy insertion, the patient developed adequate urine output through the nephrostomy tube, and her serum creatinine decreased to 1.1 mg/dL after 4 days. Nephrostography via a nephrostomy tube revealed severe pelvocaliectasis and small intrarenal pelvis without visualization of the ureter, conditions which favored extensive ureteral stricture (Figure 1). We were not able to progress the guide wire through the transplanted ureter for endoscopic management. Thus, we decided to proceed with exploration of the graft and reconstruction of the ureter.

Operation
After preparation and drape, under general anesthesia in the supine position, the retropubic space was entered through the previous hockey stick incision; the grafted ureter was identified, and it was diffusely fibrotic. Therefore, the ureter was dissected proximally to the renal hilum. No extrarenal pelvis was seen. The whole length of the ureter was fibrotic. Due to the totally fibrotic transplanted ureter and absence of a proper renal pelvis, the decision was to perform ureterocalicostomy using the patient’s native ureter. The right native ureter was found and ligated proximally with a proper length. The graft kidney was well mobilized, and vascular clamps were applied on the renal vessels. Lower pole partial nephrectomy was performed sharply to expose the lower calyx. The native ureter was spatulated and anastomosed to the lower pole calyx with 4-0 monofilament polydioxanone sutures (PDS). A 4.8F double-J ureteral stent was placed into the lower calyx, and the other site was sent to the urinary bladder. Vascular clamps of the renal vessels were removed. Lower pole parenchymal bleed sites were sutured with 4-0 PDS (Figure 2). After hemostasis and irrigation of the wound, a 16F drain catheter was placed into the retropubic space, and then the muscle and fascia were closed anatomically with 2-0 PDS. The skin was finished with 3-0 nylon sutures. The patient was transferred to the recovery room with stable condition.

After the operation, the patient had normal urine output, but unfortunately her serum creatinine rose 2.6 mg/dL. Color Doppler ultrasonography of the graft kidney showed no vascular event. After several days, the patients’ serum creatinine gradually decreased and reached the normal level. The patient was discharged from the hospital with creatinine levels in the reference range.

Follow up
The patient was followed up 1 month later. Ultrasonographic evaluation of the transplanted kidney showed normal findings. Serum creatinine was 0.9 mg/dL.

Although most patients with ESRD undergo hemo-dialysis as the initial treatment, kidney transplant results in higher survival, better quality of life, and lower maintenance costs compared with dialysis.⁵

Ureteral stricture is the most common comp-lication after renal transplant. Cold ischemia time, residual diuresis, the body mass index, donor serum creatinine, donor age, recipient age, and presence of multiple renal arteries have been identified as risk factors of ureteral stricture.^6,7 Minimal invasive treatments, such as nephrostomy tube insertion, double-J stent insertion, and balloon dilation, as well as surgical treatments, such as ureteroneocystostomy, pyeloureterostomy, and ureteroureterostomy, are the most favorable approaches for management of ureteral strictures.^3,8 The results of a study from 2018 showed that graft survival was significantly shorter in the patients managed with minimally invasive approach compared with those with no stricture; graft survival was not statistically different in patients treated with open surgery.² In the most distal ureter strictures, ureteral reimplantation is the treatment choice for ureteral strictures; however, for those with more ureteral stricture length, other procedures could be required, such as psoas hitch, Boari bladder flap, or ureteroureterostomy.

Ureterocalicostomy, first described by Neuwirt in 1948, is a salvage procedure option for surgeons faced with otherwise difficult reconstructive surgery.⁹ Ureterocalicostomy provides direct urine drainage from the lower calyx of the kidney to the ureter. It is rarely indicated for managing uretero-pelvic ureteropelvic junction obstruction with an intrarenal pelvis, or small extrarenal pelvis.^10,11 Our patient had a small intrarenal pelvis, and the total course of the graft ureter was fibrotic. Therefore, we proceeded to explore the native ureter. After partial nephrectomy of the lower pole of the transplanted kidney, it was anastomosed to the native ureter.

Our literature search discovered only 4 cases of ureterocalicostomy in transplanted kidney.^12-15 Astolfi and colleagues performed ureterocalicostomy with partial lower pole allograft nephrectomy, as we did.¹² The main complication of ureterocalicostomy is stricture formation due to inadequate excision of the parenchyma of the kidney.¹¹ Notably, this procedure should be performed in centers with high experience in management of transplanted kidney compli-cations.

Ureterocalicostomy is a problem-solving procedure in very rare cases of transplanted kidney with extensive allograft ureteral stricture and very small, contracted, and intrarenal pelvis.

Volume: 21 Issue: 4 April 2023

FULL TEXT