Metabolic findings after colocystoplasty in children.

Objectives: To investigate whether colocystoplasty has resulted in metabolic changes in the growing child during long-term follow-up according to whether cecum with ascending or sigmoid colon was used.

Methods: Twenty-eight patients (mean age at surgery 11 years) were included in the study and divided into two groups: group 1, cystoplasty with cecum and ascending colon (12 patients) and group 2, sigmoid cystoplasty (16 patients). Patients' linear growth, body mass index, and the following parameters were estimated before surgery and at 3, 6, and 12 months, and then yearly after surgery: blood and urine electrolytes (sodium, potassium, chloride, calcium, phosphorus, magnesium), creatinine, urea, blood gases, blood pH, urine pH, and blood alkaline phosphatase (ALP). All the data were statistically analyzed.

Results: In group 1, the blood ALP increased significantly (P = 0.026) during follow-up. Severe metabolic acidosis with or without hyperchloremia was found in 7 patients. In group 2, the serum sodium and serum calcium levels decreased significantly (P = 0.014 and P = 0.003, respectively); however, the blood ALP, urine sodium, and urine phosphorus levels increased significantly (P = 0.033, P = 0.027, and P = 0.026, respectively) during follow-up. A statistically significant decrease in blood pH (P = 0.022) was found after surgery. Severe metabolic acidosis with or without hyperchloremia was detected in 5 patients. The average linear growth decreased significantly (P = 0.001 and P = 0.016, respectively) 1 and 2 years postoperatively.

Conclusions: The statistically significant increase in blood ALP and decrease in serum calcium indicate bone demineralization after colocystoplasty. Our investigations in children suggest that bone demineralization is more frequent after sigmoid cystoplasty than after the use of cecum and ascending colon.