Vitamin B12 and folate after 5-12 years of continent ileal urostomy (Kock reservoir) in children and adolescents

Abstract

Objective: To assess B12 and folate deficiency after continent urinary diversion via a Kock continent urinary reservoir in children and adolescents.

Methods: Ten boys and 10 girls (10.8-18 years old at surgery) were operated with a Kock reservoir and followed for 5-12 years (mean 8.5). The follow-up period was divided into early (3 months-5 years, EFU) and late (5-12 years, LFU) follow-up. Patients were investigated for haemoglobin, serum iron, total iron binding capacity (TIBC), serum Vitamin B12, serum and blood folate, methylmalonic acid (MMA), homocystine and glomerular filtration rate.

Results: Two patients developed subnormal B12 values (median 107.5 pmol/l), one at the EFU, and the other at LFW. The B12 value decreased during the LFU compared to the EFU in nine patients, but it was still within the normal range. Two patients with renal impairment had elevated MMA with normal B12 values. Five patients had high values of homocystine with folate deficiency and/or B12 deficiency and renal impairment. Plasma folate mean value was normal during the whole follow-up. Blood folate was below normal in five patients at the EFU. Two of these five patients, in addition to three patients, had low values at the LFU. Three of four patients with remaining short terminal ileum (20-45 cm) had normal B12 values at both the EFU & LFU and one had low values at the LFU. Six patients had subnormal GFR at the LFU.

Conclusions: To a similar degree as in adults, Vitamin B12, folate and iron deficiency can occur in children and adolescents after continent urinary diversion using an ileal segment. Therefore, Vitamin B12 and folate should be monitored regularly in these patients. Serum MMA and homocystine may offer increased detection of Vitamin B12 deficiency, especially in the patients with normal renal function. Vitamin B12 deficiency is neither correlated with the time elapsed since surgery, nor with the ileum length. Patients are usually asymptomatic, so patients with true B12 deficiency should be identified and placed on life-long Vitamin B12 therapy. An adequate synthetic folic acid as supplements or fortified food is recommended for patients with folate deficiency.