Objectives: Double J stent placement at kidney transplant may reduce stenosis or leakage com-plication rates. However, placement may also increase risk for early urinary tract infection (ie, < 3 mo after transplant). In children, the usefulness of double J stent placement is not well defined.

Materials and Methods: We analyzed retrospective data from children who received transplants at the Gazi University Transplantation Center and Pediatric Nephrology (Ankara, Turkey) for outcomes related to double J stents. At our center, double J stent placement decision is made by the transplant surgery team during operation. Placements were routinely performed in all transplant recipients. Stent removal occurs within 6 week after transplant.

Results: Among 42 transplants since 2006, early urinary tract infection was seen in 7% and stenosis in 3.6% of patients, with no leakage reported. Mean stent removal time was 6 ± 0.5 weeks. Early urinary tract infection was seen in 3 recipients with posterior urethral valve and neurogenic bladder (2 recipients) and meningoma cells and neurogenic bladder (1 recipient). All 3 recipients with early urinary tract infection received clean intermittent catheterization after transplant for adequate emptying of the bladder. In our study group, stent complications such as migration (2 patients) and hematuria (1 patient) were seen, but crusting, breakage, and stone formation were not seen. The 3 patients with urinary tract infection had neurogenic bladder types, complicating the urine outflow system. Stent placement was not a significant risk factor for early urinary tract infection and but had a protective effect.

Conclusions: In our study group, we observed no risk factors for routine double J stent placement in pediatric renal transplant procedures. Stent placement was not a risk factor for early urinary tract infection. However, regardless of stent placement, when a recipient had complicated urologic outflow problems, infection became a long-term hurdle.

Key words : Children, Renal transplant, Urinary tract infection

Introduction

Urologic complications remain a major source of morbidity and occasional mortality in renal transplant, despite a reduction in their incidence of at least one-half over the past 30 years. The most common urologic complications after renal transplant are those involving the ureter.^1,2 Leaks or obstructions make up more than 90% of urologic problems after transplant, and leaks occur because of ischemic or mechanical injury to the ureter and also technical difficulties with the anastomosis.³ In addition, ureteric obstructions may be caused by twists, kinks, and technical difficulties with the anastomosis. In these settings, a benefit of stenting has been reported.^4-6 The stent generally used to protect the urinary anastomosis is the double J tube.⁶

In different transplant centers, the incidence of ureteral complications after renal transplants varies from 2% to 20%.^7-9 However, there are no relevant data for the pediatric transplant population. We present our experience with the use of the double J stent (DJS) in pediatric renal transplant patients and the infectious complications of this procedure.

Materials and Methods

This is a retrospective review of outcomes in relation to DJS use in 42 consecutive pediatric renal trans-plant procedures to 41 recipients performed at the Gazi University Transplantation Center (Ankara, Turkey) since January 2006. Of the 42 transplant procedures, 22 were for boys and 20 were for girls. Mean age was 13.4 ± 3.1 years (range, 3.5-17 y). Twenty-eight patients (67%) received kidneys from living donors, and 14 (33%) received kidneys from deceased donors.

The Carrel Patch technique was used for deceased donor transplant, and the standard technique was used for living donor transplant with continuous 6/0 (vein) and 7/0 (artery) propylene sutures (end-to-side renal artery/vein to external iliac artery/vein, abdominal aorta, and inferior vena cava in small children) used for vascular anastomosis. The graft was placed in either the iliac fossa or, in small children (< 10 kg), in the abdomen.

The immunosuppressive protocol consisted of a triple immunosuppressive regimen (calcineurin inhibitors, mycophenolic acid, and steroids) and induction therapy (basiliximab at 20 mg from day 0 and 4 in high-risk patients, such as those receiving kidneys from deceased donors and those with high panel reactive antibodies). In deceased-donor transplant procedures, antithymocyte globulin was used when delayed graft function occurred, until serum creatinine levels decreased to 3 mg/dL.

Before start of surgery, patient bladders had been filled with isotonic saline solution via a Foley catheter. An incision to the bladder was made over the anterior part of the dome, and a small opening was made in the mucosa. The graft ureter was trimmed, assessed for good vascularity, and spatulated at the end before anastomosis. Routine DJS (4.8F, 14 cm) placement was performed in all cases. By day 5 after transplant, the Foley catheters and pelvic drains were removed. At 5 weeks after transplant, the DJS was removed under sedation on an outpatient basis by either the pediatric surgery or the urology department.

A modified version of the Lich-Gregoir method with the Haberal corner-saving technique was used with DJS for ureteroneocystostomy. The Haberal corner-saving technique has been previously described.10 Briefly, a double 6-0 monofilament polydioxanone running suture was used for ureteral reimplantation. For the corner-saving technique, the first suture stitch begins from 3 mm ahead from the corner of the posterior wall of the graft ureter and corner of the bladder. After the last stitch (3 mm below the corner of the ureter), both ends of the suture material are pulled to decrease the excess, and the posterior walls of the ureter and bladder are approximated tightly. Then, the anterior wall is sewn either with the same suture or with another running suture.

Results

Early urinary tract infection (UTI; ie, < 3 mo after transplant) was seen in 7%, leakage was seen in 3.6%, and no stenosis was seen in the 42 pediatric renal transplant procedures. Mean DJS removal time was 7 ± 0.5 weeks. Early UTI was seen in 3 recipients: 2 with posterior urethral valve and neurogenic bladder and 1 with meningoma cell and neurogenic bladder. All 3 recipients with early UTI received clean intermittent catheterization after transplant for adequate emptying of the bladder. In our study group, complications of DJS included spontaneous DJS migration (2 patients) and hematuria (1 patient). Crusting, breakage, and stone formation were not seen.

Discussion

Incidence of urologic complications leading to graft failure has decreased substantially over the past decades to below 5%.¹¹ Preservation of the distal ureter blood supply during donor nephrectomy, sparing of the periureteric fat during graft kidney harvesting, and the extravesical reconstruction technique may be responsible for these advancements in outcomes.^12-16 In this setting, a benefit of stenting has been reported.6 The stent generally used to protect the urinary anastomosis is the DJS.⁵

The routine use of a ureter DJS remains controversial, with a reported increased incidence of UTIs and ureter obstruction. The results of a prospective, randomized trial demonstrated that routine use of a ureteral stent in patients who undergo renal transplant leads to a significant decrease in urologic complications.¹⁷ Routine stenting in deceased-donor transplant procedures has also been recommended, as a protective effect has been observed in this group.¹⁸ The use of stents ensures mucosa-to-mucosa anastomosis without causing inadvertent obstruction. An indwelling stent excludes leak, obstruction, and transient edema as a cause of early postoperative oliguria. Other studies have shown that stents decrease the rate of other urologic complications in adults, but there remains a paucity of data in the pediatric age group.

Pediatric transplant differs from that in adults regarding the primary cause of renal failure and outcomes of deceased-donor transplant procedures. We believe that the Haberal technique provides better visualization of both mucosae, simplifies suture placement in the posterior walls, and provides better identification of the lumen of the ureter. After the posterior walls have been approximated, it is also easy to complete the anastomosis with the same suture. These advantages clearly make this anastomosis superior with regard to preventing technical errors.

Ureteral stents are associated with a significant reduction in ureteral complications but may increase early UTI risk. In our study, early UTI was seen in 3 patients (7%) who had neurogenic bladder types that complicated the lower urine outflow system. Using ureteral stents in renal transplant significantly decreases early urologic mechanical complications and is cost-effective.^17,18 The use of DJSs is recommended in all renal transplant recipients; however, insertion recommendation varies between 30 days to 4 weeks.¹⁷ Despite the duration of DJS removal in our study being longer than shown in general practice, we did not see any related complications.

Conclusions

In our study group, there were no increasing risk factors for routine DJS placement in pediatric renal transplant. Regardless of DJS placement, when the recipient had complicated urologic outflow problems, infection was a long-term hurdle. In addition, the use of DJS may not be associated with increased UTI in the early period for renal transplant recipients.

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