Long term serum electrolytes and arterial acid-base changes after continent urinary diversion: the rectosigmoid bladder versus the urethral kock reservoir

ABSTRACT

To compare the long term serum electrolytes and arterial acid-base changes following the use of rectosigmoid bladder [RSB] and the urethral Kock reservoir [UKR] for continent urinary diversion. Serum electrolytes and arterial acid-base changes were studied in 50 patients with RSB and 40 with UKR after cystectomy for bladder carcinoma. All the patients have a cancer free survival of at least 5 years. No significant serum electrolytes disturbances were noticed apart from hyperchloraemia which was significantly more common in RSB than in UKR [p < 0.001]. Chronic metabolic acidosis was diagnosed in 13 [32.5%] and in 25 [88%] of UKR and RSB respectively [p < 0.001]. The severity of acidosis was generally less in UKR, moderate to marked acidosis was found in 30% and 92% of the patients with acidosis in UKR and RSB consecutively. Patients with continent urinary reservoirs are at risk of developing chronic metabolic acidosis. The incidence and severity was lower following UKR compared to RSB. UKR imparts an insignificant metabolic insult over the long term to patients with normal renal function. Regarding absorptive complications the ileum is favoured than the rectosigmoid segment in the construction of continent urinary reservoirs