Spontaneous Rupture of Kidney Due to Posterior Urethral Valve–Diagnostic Difficulties
Previously healthy 6-week-old boy, born to a GIII PIII, birth weight 2900g, was admitted to the district hospital with fever, vomiting and oliguria persisting for several hours. Family history was of no significance. On admission, infant's general condition was poor. A distended abdomen, tense and tender on palpation, was noted. Urethral catheterization was difficult. Laboratory investigations revealed: WBC 3.7 K/u, Hb 8.4 g/dl, urea 70 mg/dl, CRP 132.3 mg/l, procalcitonine >200 ng/ml, and uncompensated metabolic acidosis. Urine microscopy revealed pyuria and few fresh red cells. Ultrasound examination showed a left kidney measuring 70 mm in length with a dilated pelvi-calyceal system and an enlarged hydronephrotic right kidney measuring 90 mm in length. Treatment was started with cefotaxime, vancomycin, dopamine and furosemide. The infant's general condition improved, but CRP continued to rise (281.5 mg/l). Serum urea, creatinine and procalcitonine were 98.0 mg/dl, 1.0 mg/dl and 180.74 ng/ml, respectively. Blood and urine cultures were negative. A diagnosis of bilateral hydronephrosis was made.\nOn the 2nd day of hospitalization the infant was transferred to our Department. A distended abdomen with a right sided large palpable mass was found. Laboratory tests showed CRP 309.4 mg/l, urea 116 mg/dl, creatinine 1.81 mg/dl, Hb 10.5 g/dl and compensated metabolic acidosis. Urine output in less than 24-hours measured about 280 ml. Cefotaxime and vancomycin were discontinued and meropenem commenced. Abdominal ultrasound demonstrated left kidney 7×2.8 cm, with mild pelvic dilatation, and right kidney 11×6.6 cm with a dilated and deformed collecting system. The upper and middle calyces seemed mostly dilated with a total volume of about 216 ml, pelvic volume 3 ml. Right kidney parenchyma was compressed. The bladder was empty. Hydronephrosis was considered, but a suspicion of kidney compression by an extraneous cystic structure was also raised. Due to worsening of the infant's condition and equivocal ultrasound images, he was qualified for an urgent laparotomy.\nDuring surgery a huge cyst was found in the peritoneal cavity, encircling almost the whole right kidney and connected to the renal capsule by its capsule. The cyst contained about 500 ml of watery bright fluid which was resected revealing that its wall was a fragment of the anterior wall of the renal capsule. Drains were set up to postoperative sites. Additionally, the bladder was noted to have a thick and hard wall.\nIn the following 24-hours renal function improved (urea 47 mg/dl, creatinine 0.95 mg/dl), CRP decreased to 65 mg/dl. Urine output was 2-5 ml/h. Bright yellow draining fluid, about 20 ml/h, was noted to have similar biochemical properties to urine: urea 496 mg/dl, urea nitrogen 231.8 mg/dl, creatinine 9 mg/dl. Follow up abdominal ultrasound reported a slightly wider right pelvi-calyceal system, with a small fluid collection near the upper pole (). Voiding cystourethrography showed trabeculated bladder wall. Cystoscopy revealed urethral structures which could correspond to disrupted posterior urethral valves. Valve ablation was performed. Histopathologically the wall of the resected cyst turned out to be the right kidney capsule and was reported as Pseudocystis in inflammatione chronica. Retrospectively spontaneous kidney rupture due to posterior urethral valves was diagnosed.\nAfter 21 days of treatment, inflammatory markers and renal function normalized. Renoscintigraphy performed 6 weeks post surgery revealed cumulative renogram curves of both kidneys, the right kidney (operated) contributing 81.5% of renal function and the left kidney 18.5%. At 20 months follow up review both renal function parameters and blood pressure values were normal. Ultrasound examinations revealed persisting mild dilatation of both pelvi-calyceal systems. History regarding urinary tract infection was negative.