Antegrade percutaneous dilation of ureteral strictures after kidney transplantation

Endoscopic incision for obstruction of vesico-ureteric anastomosis in transplanted kidneys

OBJECTIVE

To report our experience of endoscopic incision for obstruction of vesico-ureteric anastomosis (VUA) in transplanted kidneys.

PATIENTS AND METHODS

Between February 2001 and March 2006, six men and two women (mean age 38 years, range 27-57) with VUA obstruction in their transplanted kidneys were treated by percutaneous nephrostomy and endoscopic incision. After the anastomosis was completely cut, two JJ stents were placed in the ureter for 4-6 weeks. During the follow-up, serum urea, creatinine and uric acid levels were measured, and urine culture, ultrasound examination and washout renal scintigraphy were performed every month for the first 6 months, then every 3 months.

RESULTS

In all, 12 procedures of endoureterotomy were performed and all procedures resulted in successful incision of the obstruction. There were no complications during or after the procedures. The retrograde and antegrade endoureterotomies were performed with four procedures in two patients and eight procedures in six patients, respectively. At a mean (range) follow-up of 16 (4-45) months, five of the eight patients had ureteric patency and stable renal function. In three patients there was a recurrence of obstructive uropathy, immediately after JJ stent removal, which finally required open surgical correction.

CONCLUSIONS

Percutaneous nephrostomy and endoscopic incision is safe and effective for obstruction of VUA in transplanted kidney, and it can be the initial therapy for ureteric obstruction in transplanted kidneys; however, open surgical reconstruction should be considered if the initial endoscopic incision procedure fails.

Ureteral stenosis in HDAF pig-to-primate renal xenotransplantation: a phenomenon related to immunological events?

The aim of this study was to analyze the incidence of ureteral stenosis in a life-supporting human decay-accelerating factor (hDAF) transgenic pig-to-cynomolgus monkey kidney transplantation model and determine the role of possible immunological events in its pathogenesis. Thirty consecutive bi-nephrectomized cynomolgus monkeys received a kidney from hDAF transgenic pigs with or without a ureteral stent. Four monkeys were euthanized prematurely after transplantation. In the remaining 26 cases, the mean survival was 24 +/- 19 days. Except in one case, there was a close relationship between ureter and kidney in terms of type and severity of rejection. There were six ureteral stenoses; five were repaired by stent positioning and resurgery extended survival for an additional 16 +/- 10 days. The stenotic ureters showed diffuse acute humoral xenograft rejection (AHXR), while all cases with no or only focal signs of ureteral rejection never revealed ureteral obstruction. Use of a ureteral stent extends the survival of a xenografted primate, thereby helping to clarify the immunological events surrounding the onset of AHXR in kidneys in long-term xenograft recipients.

Results of pyeloureterostomy after ureterovesical anastomosis complications in renal transplantation

OBJECTIVES

The most frequent urologic complications after renal transplantation involve the ureterovesical anastomosis (ie, leakage, stenosis, and reflux), with a frequency of 1% to 30% in different series. We present the results of pyeloureterostomy using the recipient's ureter.

METHODS

From 1988 to 1996, 570 cadaveric renal grafts were performed at our institution. A Lich Gregoir ureterovesical anastomosis was used in every case. Complications involving the anastomosis occurred in 19 cases (3.3%), with 10 stenoses (1.7%), 6 cases of leakage (1.1%), and 3 of reflux (0.5%). The mean donor age was 36.2 years, and the mean duration of cold ischemia was 29.4 hours. The mean recipient age was 41.3 years. Corrective surgery was performed 0.09 years (range 0.01 to 0.22) after transplantation for leakage, 1.13 years (range 0.14 to 5.11) for stenosis, and 5.55 years (range 0.51 to 9.71) for reflux. The recipient's ureter was stented with a ureteral catheter before median laparotomy, except in 3 cases of early leakage (less than 3 days). The recipient's ureter was cut, without the need for ipsilateral nephrectomy, and sutured to the graft pelvis. A nephroureterostomia stent (Gil Vernet stent) (12 cases) or a double J ureteral stent (7 cases) was used for urinary drainage.

RESULTS

One graft was lost on day 1 through renal vein thrombosis. Percutaneous nephrostomy was performed on day 2 to clear an obstruction of the double J ureteral stent in one case, and a double J ureteral stent was inserted on day 2 because the nephrouretrostomia stent was incorrectly positioned in another case. Pyelographic controls on day 15 were normal in every case. The mean follow-up was 2.25 years (range 0.24 to 6.1) (2.9 years for leakage, 2.08 years for stenosis, and 1.44 years for reflux). One patient died with a functional graft 3 years after surgery. One graft was lost 4 years after surgery through chronic rejection. There were no complications affecting the ipsilateral kidney. No further ureteral complications occurred after surgery. The mean creatinine level 3 years after surgery was 1.59 mg/dL.

CONCLUSIONS

Pyeloureterostomy is a safe and permanent treatment for complications of ureterovesical anastomosis and gives excellent results. The technique requires stenting of the recipient's ureter and graft drainage with a nephroureterostomia stent or a double J ureteral stent.

Endoscopic retrograde stenting for allograft hydronephrosis

BACKGROUND AND OBJECTIVES

Ureteral obstruction occurs in 2% to 10% of all renal transplant recipients. Antegrade endourologic intervention has been the gold standard of therapy but carries significant morbidity. This study was designed to investigate the feasibility of retrograde stenting of these difficult ureters and to determine whether it can be performed with minimal morbidity without general or regional anesthesia.

METHODS

Ninety-seven consecutive patients were found to have renal allograft hydronephrosis by ultrasonography, between August 1993 and March 1997. Of these, 61 (63%) had confirmation of obstruction by MAG-3 imaging, with equivocal results in 25 (26%). The remaining 11 patients had a rising creatinine concentration despite Foley catheter drainage. All patients had retrograde stenting attempted under local anesthesia followed by intravenous sedation if necessary. If stent placement was unsuccessful, the procedure was repeated under regional or general anesthesia.

RESULTS

A total of 85 patients (88%) were managed successfully with retrograde stenting. Of these procedures, 24 (28%) were performed under local anesthesia alone, while 57 (67%) required both local anesthesia and intravenous sedation. Only 4 patients (5%) required general anesthesia. No patient suffered any morbidity associated with retrograde stenting. Of the 12 patients in whom retrograde stenting failed, 2 had renal allograft rupture and 10 had ureteral necrosis at surgical exploration.

CONCLUSIONS

Retrograde stenting of the hydronephrotic renal allograft can be achieved with a high success rate and minimal morbidity, usually without general or regional anesthesia. If the ureter cannot be managed in a retrograde fashion, a high index of suspicion for a serious allograft complication should exist.

Antegrade balloon dilation of postoperative ureterovesical junction obstruction in children

Obstruction of the ureterovesical junction is an uncommon but well-recognized complication of ureteral reimplantation that traditionally has been treated by surgical correction [1, 5-9]. We report our experience with antegrade balloon dilation (ABD) of these strictures in two children. Obstruction was confirmed by diuretic renogram and pressure perfusion studies prior to ABD. Clinical follow-up was done at 3 months and 14 months, and ultrasonographic studies revealed resolution of the hydronephrosis. In addition, diuretic renograms showed complete washout of radiotracer. Morbidity was limited to episodes of pyelonephritis that readily responded to medical management. ABD of ureteral strictures is a relatively simple procedure with a potential for a high success rate and low morbidity. This modality should be considered as the first line of treatment in patients with distal ureteral obstruction after reimplantation.

Endo-urological cold-knife incision for ureteral stenosis after renal transplantation

Cold-knife incision of stenoses in the transplant ureter was performed in 11 patients with upper urinary tract obstruction in renal transplants. The operations were complicated by bleeding in 2 patients and the graft had to be removed in 1 of them. The stenoses could be treated successfully in 10 of the 11 patients (91%) and the mean serum creatinine concentration decreased significantly from 3.4 to 1.8 mg./dl. After a mean of 26 months only 1 obstruction recurred, so the long-term success rate was 82%. Because of the favorable long-term results and the low incidence of complications, we recommend endo-urological cold-knife incision of ureteral stenosis as the first-line treatment for upper urinary tract obstruction in renal transplants.

Percutaneous antegrade dilation of ureteral strictures in kidney transplants

Transplant ureteral stricture can be treated by either incisional surgery or percutaneous endoluminal dilation. We present 17 cases of percutaneous antegrade endoluminal dilation. The results of this procedure were satisfactory, with a 70% success rate that seems to be maintained during long-term followup. The results were better if dilation was done on a short and recent juxta-anastomotic stricture stented with a 10F Double-J* catheter for 2 months.