EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Kidney transplant is the gold standard surgical treatment for patients with end-stage chronic kidney disease. Over the past decade, the frequency and prevalence of chronic kidney disease in children have been increasing, with it being a serious problem worldwide. Kidney transplant in Uzbekistan is still at an early stage, with the first successful kidney transplant performed in 2018. Here, we describe a successful kidney transplant in a pediatric female patient with a congenital abnormality of the urinary tract. The patient first showed symptoms at 7 years of age and was diagnosed with urolithic illness with inflammation of both kidneys. At presentation, she was 14 years of age with end-stage chronic kidney disease (diagnosed with stage 5 chronic kidney disease at age 13 years) caused by an anomaly in the development of the urinary tract. She received a kidney transplant from her mother as a living donor. There was vesicoureteral reflux on both sides and ureterohydronephrosis from 2 sides. On day 9 posttransplant, her creatinine level decreased from 0.40 to 0.066 mmol/L. Doppler ultrasonogram showed normal size and echogenicity of the graft, as well as adequate blood flow in the renal and iliac vessels. The patient was discharged on day 10 posttransplant in a satisfactory condition. In about 50% of cases, the cause of chronic renal failure in children is congenital anomalies of the urinary tract. The most common causes of hydronephrosis in newborns and children are vesicourethral reflux, which leads to the expansion of the urinary tract collecting system and the development of chronic renal failure. Early and accurate diagnosis and timely treatment of urinary tract abnormalities can reduce the incidence of end-stage chronic kidney disease in children.

Key words : Chronic kidney disease, Congenital urinary tract abnormality, End-stage renal failure, Pediatric surgery, Renal transplantation

Chronic kidney disease (CKD) is a serious health issue around the world.^1-5 In Europe, the prevalence of stage 5 CKD in children is 11 to 12 per million population.^6-9 Worldwide, the prevalence of stage 5 CKD is 80 cases per million of the child population.¹⁰ The frequency of stage 5 CKD increases with age and mainly presents in those from 15 to 19 years of age.^10,11 Men have a higher incidence of CKD than women, since the incidence of congenital anomalies of the urinary tract is more common than shown in female patients.¹⁰ About 50% of the causes of CKD in children are congenital anomalies of the kidneys and urinary tract.⁶

Kidney transplant is the therapy of choice in children with end-stage renal disease (ESRD). In Uzbekistan, as in other countries, CKD in children is a leading health issue.¹² From 2017 to the present in Uzbekistan, more than 10 kidney transplants have been performed in children with urinary tract abnormalities. Here, we present a clinical case of a kidney transplant to a child from a mother.

A 14-year-old girl developed CKD at the age of 7 years, with diagnosis made after the patient had lower back pain. A diagnosis of urolithic illness with an inflammatory process was made. At the age of 13 years, the patient had stage 5 CKD and program hemodialysis was prescribed, which she received for 1 year. During magnetic resonance imaging and computed tomography examinations, signs of bilateral megaureter transformation were revealed. On the right, the ureter was elongated and curved, which expanded to 15.7 mm. A conical narrowing reaching the entrance to the bladder was also visualized. On the left, in the pelvic-ureteral segment, the ureter from the ureteropelvic segment level was not visualized. Diagnostic cystoscopy revealed vesicourethral reflux on both sides. The openings of both ureters did not completely close, and the diameter of the right ureter only opened to about 1.5 cm and the left only opened to 1.7 cm.

The donor was the mother of the patient. HLA compatibility showed matches of HLA-A, HLA-B, and HLA-DR of 1 match each, with 4% cross-matches. The patient underwent heterotopic kidney transplant in the right iliac region with the imposition of an end-to-end anastomosis between the kidney artery and the internal iliac artery and end-to-side anastomosis between the renal vein and the external iliac vein. Uretero-vesical anastomosis was performed in accordance with the standard Lich-Gregoire procedure with double J stenting. Next, we performed duplication of the wall of the right ureter with the imposition of ureterocystoneostomy anastomosis on the right with double J stenting and imposition of ureterocystoneostomy anastomosis on the left with double J stenting. Immediate graft function was observed during the operation.

The recipient received standard three-component immunosuppressive therapy. The daily diuresis was 5400 mL (Table 1), which gradually decreased to 3200 mL on day 9 postsurgery. The creatinine level decreased from 0.40 to 0.066 mmol/L on postoperative day 9. Moderate proteinuria of 0.066 g/L on day 2 and 0.198 g/L on day 4 after surgery was also noted. The absence of proteinuria was observed only on day 5 postsurgery. An ultrasonogram of the transplanted kidney on day 7 showed smooth and clear contours of the kidney, with dimension of 10.2 × 4.6 cm. The size of the kidney cortex was 1.4 to 1.5 cm. There was no pronounced pyramidal pattern, and the heart and pelvis were not expanded. Blood flow volume in the arcuate arteries was at 28.7 cm/s with resistance index (RI) of 0.61. Blood flow volume in segmental arteries was at 50.6 cm/s with RI of 0.65. Blood flow volume in anastomosis was 120.4 cm/s with RI of 0.72. These findings showed that the transplanted kidney had function within normal limits.

On day 17 after transplant, an ultrasonography of the native kidney on the right showed a size of 7.3 × 2.5 cm with smooth contours. Respiratory mobility was preserved, and the thickness of the kidney parenchyma (size of kidney cortex) was 0.4 to 0.6 cm. The pelvicalyceal system of the kidney and the pelvis were not expanded, and the ureter was not visualized. The left kidney size was 6.3 × 2.4 cm. Respiratory mobility was preserved, and the thickness of the kidney cortex was 0.3 to 0.4 cm. Heart rate was normal, and pelvis was not expanded. The calyx and the ureter in the upper third were normal. The patient had ureteral stents removed on day 27 posttransplant and was discharged in a satisfactory condition.

Given its growing prevalence in recent decades, CKD has become a major health problem worldwide. The main causes of CKD in children are congenital anomalies of the kidneys and urinary tract, steroid-resistant nephrotic syndrome, chronic glomerulonephritis, and kidney ciliopathy. Kidney transplant surgery in children has become a common surgical operation and is associated with high success rates. Kidney transplant in Uzbekistan began in 2018.¹² The patient described in our report did not have a timely diagnosis of abnormal development of the urinary tract. During diagnostic cystoscopy, insufficiency of the vesicoureteral segment on the right side was revealed, which caused ESRD. For this patient, kidney transplant and simultaneous bilateral duplication of the ureter were the best treatment options and were successful. Early and accurate diagnosis and timely treatment of urinary tract abnormalities can reduce the incidence of ESRD in children.

Volume: 20 Issue: 5 May 2022 - Supplement - 3

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