Purpose
MAINZ pouch I urinary diversion provides a high-capacity, low-pressure reservoir. The use of terminal ileum can cause a decrease of vitamin B12 levels. Symptoms caused by vitamin B12 deficiency are rare, but some are irreversible, therefore annual check-ups are recommended. In this study the vitamin B12 levels in the above patients were analyzed in retrospect.
Material and Methods
The ileocecal segment was used for urinary tract reconstruction in > 80 children ≤17 years of age. B12 levels were determined at various time points within up to 21 years after surgery in 63 patients (8 with ileocecal bladder substitution, 55 continent cutaneous diversion). B12 values below 200pg/ml were considered low and substitution therapy was recommended. Values after substitution therapy were excluded from further analysis.
Results
A total of 170 B12 levels were determined over an average of 8 years postoperatively (1-21). In 27/63 patients, ≥3 (3-8, median 4.0) B12 values were available for analysis. In 7/27 patients values only showed some undulation or increase over time (15 % - 135 % (median 46 % )). In the remaining 20 patients a general decrease (8 % - 61 % median -36 % ) was observed. 5 of 63 patients (8 % ) were in need of vitamin B12 supplementation. Overall, a continuous slow decrease of B12 values was observed over the follow-up period of 21 years in the majority of the patients.
Conclusions
Patients in whom the ileocecal segment was used for reconstruction of the urinary tract in childhood are at risk for development of vitamin B12 deficiency. There is a wide variation of the vitamin B12 levels over time, however, a decrease below 200pg/ml has to be considered relevant and supplementation is needed.
In our patients we observed a slow but permanent decrease of vitamin B12 levels in more than 60 % of the patients, 8 % underwent substitution of vitamin B12.
Annual serum B12 levels determination are recommended beginning 5 years postoperatively.
