Influence of pH on reservoir mucosal absorption/-secretion and tubular and glomerular function. Studies in patients with a continent ileal reservoir for urinary diversion

Evaluation of Kock urinary reservoir function in children and adolescents at 3-10 years' follow-up

The aim of this study was to evaluate Kock reservoir function in children and adolescents operated for congenital urinary incontinence and to determine the complication rate. Reservoir function was investigated in 13 children (age range 10.8-16 years) and 7 adolescents (age range 16-18 years) through enterocystometry, enterocystoscopy and patient history. Patients were followed up for 3-10 years. The follow-up was reported as early (3 months-2 years) and late (2-10 years) postoperative periods. At early follow-up reservoir capacity was high in four patients and normal in the remaining patients. A low reservoir pressure was accompanied by high capacity and compliance. On enterocystometry first sensation for emptying was experienced in 82% of patients at early follow-up and 92% at late follow-up. Reservoir contractions were recorded in 60% of patients at early follow-up and 65% at late follow-up. The contractions were recorded at an average reservoir capacity of 270 ml at early follow-up and 340 ml at late follow-up. The complication rate was high in the child group compared with that in adolescents. Of 13 patients with at least one reservoir complication 10 were from the child group. Nipple dysfunction (angled nipple, prolapsed or stenosed stoma) occurred in 35% of patients, stones in 40% and bleeding during catheterization in 15%. Revision was performed in 38% of the child group and 15% of the adolescents. Reservoir perforation was observed in two patients at 6 and 9 years postoperatively. At late follow-up continence was excellent in 17 of 19 patients and good in 2. We conclude that the Kock reservoir is a good modality for urinary diversion, but the complication incidence is high in the child group (<16 years). Stability of the reservoir in terms of volume and low internal pressures was achieved one year after operation, except in the patients with infrequent reservoir emptying. A time-related increase in the reservoir sensitivity and contractility was reported on enterocystometry. Nipple dysfunction is common during the first two years after surgery, particularly in the child group. Stones may form 3-4 years after surgery. Satisfactory continence was achieved in all patients, although a revisional operation was necessary in some patients in order to obtain permanent continence.

Early and late metabolic alterations in children and adolescents with a kock urinary reservoir

OBJECTIVE

To assess the early and late metabolic effects of urinary diversion in children and adolescents with a Kock urinary reservoir.

PATIENTS AND METHODS

Thirteen children (aged 10.8- 16 years) and seven adolescents (aged 16-18 years; 10 girls and 10 boys), underwent surgery for congenital urinary incontinence. They were followed for 3-10 years (mean 6.5), divided into an early (3 months to 2 years) and a late (2-10 years) period, and assessed for renal function and any metabolic effects.

RESULTS

At the early and late follow-up, one of 19 and three of 16 patients, respectively, had metabolic acidosis. Hyperchloraemia was present in four of 20 patients at the early and in eight of 18 at the late follow-up. Serum creatinine was increased in four of 20 patients at the early and eight of 18 at the late follow-up. In patients with infrequent reservoir emptying (</=4 times/day), the serum creatinine level was increased in seven of 13 at the early and eight of 10 at the late follow-up (P<0.05). The glomerular filtration rate was below normal in four of 20 patients preoperatively, in six of 19 at the early and in eight of 18 at the late follow-up.

CONCLUSIONS

The continent ileal reservoir in children and adolescents produces similar changes to those previously reported in adults. However, almost all patients with metabolic disorders were younger than 16 years at operation. The pre-existing impairment of renal function, together with associated congenital anomalies, mental and/or physical disorders, young age, recurrent urinary tract infections and infrequent reservoir emptying, leads to deterioration in renal function after the Kock operation. Even with this risk, the Kock pouch remains a viable alternative to other forms of continent urinary diversion, because it has a wide calibre stoma, allowing large-bore catheters, and is therefore especially suitable for individuals with weak hand function, e.g. quadriplegic or meningomyelocele patients. However, as shown by these results, the child with a Kock pouch requires continuous medical attention.

Serum levels of IgG antibodies against Tamm-Horsfall protein and urinary excretion of NAG and alpha-1-microglobulin as possible markers for tubular damage in patients with a continent ileal reservoir for urinary diversion

Serum IgG antibodies against Tamm-Horsfall protein and urinary excretion of NAG and alpha-1-microglobulin were measured in 26 patients with a Kock reservoir for continent urinary diversion or orthotopic bladder reconstruction in order to detect any signs of tubular damage. None of these markers for tubular damage was correlated to the postoperative observation time ranging between 2 and 16 years. No correlation was found between these markers and signs of renal scarring or upper urinary tract dilatation as judged from urographies. A positive correlation was demonstrated between NAG excretion and antibodies against Tamm-Horsfall protein. The annual reduction in GFR was increased in patients with elevated alpha-1-microglobulin excretion but not in patients with elevated titres of antibodies against Tamm-Horsfall protein or increased NAG excretion. Patients with previous or present reflux nipple problems had elevated excretion of alpha-1-microglobulin. Regular determinations of alpha-1-microglobulin excretion appear to be of value in the follow-up of these patients.

Renal tubular dysfunction after urinary diversion

Renal tubular function can be assessed by measuring low molecular weight proteins in urine. In the present study, urinary levels of protein HC, also called alpha 1-microglobulin, were determined in 84 patients, 3-17 years after conduit diversion or continent urinary reconstruction. Increased excretion of protein HC, indicating tubular dysfunction, was found in 30 patients (36%), but was slight in most cases. Among patients with GFR > 45 ml/min/1.73 m2 at latest follow-up, the fall from preoperative GFR was greater in those with elevated levels of protein HC than in those with normal levels (p < 0.01). No permeation of protein HC through the intestinal mucosa in contact with urine could be demonstrated. Urinary protein HC may be a suitable marker for detecting early renal impairment after urinary diversion.