En-Bloc Pediatric Kidney Transplant to Adult Recipient with Two Different Ureterovesical Anastomosis Techniques

Background

Kidney transplantation (KT) is one of the most recommended treatment options for patients with chronic kidney disease (CKD). Since Meakins et al. [1] reported the first successful pediatric en-bloc kidney transplantation (EBKT) to an adult recipient, many case reports of KTs using small en-bloc graft kidneys to an adult recipient have been published with good long-term outcomes reported [2–5]. Kato et al. [6] first reported a partial bladder transplantation with EBKT to avoid double ureteroneocystostomies. However, it is unclear which type of vesico-ureteral anastomosis is better in pediatric EBKTs to adult recipients. Therefore, we report 2 cases to support that small pediatric EBKT to adult recipient, with different ureterovesical anastomoses, is a safe and acceptable treatment option for CKD. This case report was reviewed and approved by the Institutional Review Board at Chonbuk National University hospital (IRB No. 2018-03-024).

Case Report

For the first case, the pediatric donor was a 5-month-old boy who weighed 7.24 kg, and who died of hypoxic brain death (initial serum creatinine of the donor was 0.41 mg/dL; estimated glomerular filtration rate (eGFR) was 194.8 mL/min/1.73 m2, with normal range of urine output, without proteinuria). The first case recipient was a 48-year-old man who weighed 76.8 kg and who had CKD secondary to diabetes and hypertension. He had been on peritoneal dialysis for 5 years before transplantation.

For the second case, the donor was a 4-year-old boy who weighed 15.5 kg, and who was declared brain death due to hypoxic brain injury (initial creatinine was 0.45 mg/dL; >2000 mL of daily urine output, without proteinuria). The second recipient was 54-year-old man who weighed 69 kg and who had CKD secondary to diabetes and hypertension. He had been on hemodialysis for 24 months before transplantation.

The first pediatric donor’s urinary bladder was retrieved in continuity with bilateral ureters and kidneys that were harvested en bloc, with the proximal end of the aorta and inferior vena cava (IVC) oversewn (Figure 1A). The distal end of the donor’s infrarenal aorta was anastomosed end-to-end to the recipient’s right internal iliac artery with 7-0 Prolene (polypropylene) and the distal end of the donor’s infrarenal inferior vena cava (IVC) was anastomosed end-to-side to the recipient’s right external iliac vein with 6-0 Prolene by continuous non-locking suture. The graft bladder patch was anastomosed to the recipient bladder with running 5-0 Maxon (polyglyconate) suture by full-thickness technique without insertion of double-J catheters (Figure 1C), and the donor’s en-bloc kidneys were laid on the psoas muscle perpendicular to the right iliac vessels (Figure 1E). The cold and warm ischemic times were 170 and 39 minutes, respectively.

The second pediatric donor’s kidneys were harvested en bloc with bilateral ureters (Figure 1B). In the bench work, the stump of both proximal aorta and IVC were closed with continuous suture, and ureteroplasty was accomplished by side-to-side anastomosis with the distal ureters (Figure 1D). The distal end of the infrarenal aorta and the IVC of the graft were anastomosed end-to-side to the recipient’s right internal iliac artery and external iliac vein, respectively, by continuous non-locking suture with Vascufil (polybutester) 6-0. The graft ureter was anastomosed to the anterior dome of the recipient bladder with Maxon 5-0 in continuous suture by full thickness technique without double-J stent insertion (Figure 1F). The cold and warm ischemic times were 197 and 33 minutes, respectively.

For the first recipient, tacrolimus, mycophenolate mofetil, and prednisolone were used as immunosuppressants. Renal Doppler ultrasound at postoperative day 4 showed normal range of kidney size (7 cm) and arterial resistive index (0.65–0.75), demonstrating normal patency of vessels in both graft kidneys, without stenosis (Figure 2A). Renal scan performed at postoperative day 5 with 99mTc-mercaptoacetyltriglycine revealed normal perfusion and excretion of both graft kidneys. Serum creatinine decreased to 1.67 mg/dL at 14 days post-transplantation. During follow-up at 29 months, the recipient was maintaining good urine output and normal serum creatinine (0.80 mg/dL) with normal eGFR (103.4 mL/min/1.73 m2).

The second recipient was also given tacrolimus, mycophenolate mofetil, and prednisolone under the same protocol. Renal Doppler sonography performed at day 4 showed normal range of kidney size (7 cm) and upper normal limit value of the resistive index (0.81) (Figure 2B). Renal scan with 99mTc-mercaptoacetyltriglycine on day 4 showed normal renal excretion. The patient was discharged on day 14 with decreased serum creatinine (1.12 mg/dL). Follow-up renal Doppler ultrasound at 14 months showed upper normal limit range of the resistive index (0.75–0.77). At 100 months of follow-up, serum creatinine was 0.69 mg/dL and eGFR was 101.0 mL/min/1.73 m2, without urinary complications.

Clinical characteristics of the 2 recipients in this study are summarized in Table 1.

Discussion

With the increasing demands for grafts for KT and the shortage of donor kidneys, pediatric EBKT to adult recipients should be considered a useful strategy for patients on the KT waitlist [2]. Small pediatric donor kidneys have been underutilized because of high rates of vascular complications and rejections [5,7]. Anastomosing small graft ureters and the bladder is a challenging technique that requires ureteroneocystostomy or augmentation of the bladder segment of graft. Ureteroneocystostomy requires technical skill for ureterovesical reconstruction and long surgery time. However, using the full length of the bilateral ureters with donor’s bladder segment has several benefits over ureteroneocystostomy [8,9].

It requires much less technical skill for ureterovesical reconstruction and has a shorter operation time. Furthermore, the natural anti-reflux mechanism at the ureterovesical junction and tension in ureters could be preserved.

In our 2 cases, we performed different anastomoses between the graft ureters and the bladder in each patient. The use of the bladder segment with EBKT was applied to the first recipient. In the second recipient, ureteroplasty was done by joining the distal ureters to widen the diameter of the ureter, which would be beneficial in preventing stricture due to ureteroneocystostomy. All recipients showed increased kidney size and normal renal function during follow-up periods without serious complications such as rejection, thrombosis, or urinary complications.

Conclusions

In conclusion, the favorable outcomes of our 2 cases could support the previous reports demonstrating that small pediatric EBKT to an adult recipient is safe. Although anastomosis with the bladder segment of the graft is easier to perform and faster compared with ureteroneocystostomy, with careful and skilled management, both techniques could be acceptable and provide good outcomes. Therefore, pediatric EBKT to an adult recipient should be considered as an acceptable treatment option for CKD.