Determinants of bone loss in patients with Kock ileal urinary reservoir.

The purpose of the present study was to determine the change in bone mineral density (BMD) measured with dual energy X-ray absorptiometry (DXA) in patients with Kock reservoirs for urinary diversion who were examined with the same technique 3 years earlier, and relate the changes to kidney function and variables reflecting bone metabolism. A total of 28 patients with Kock ileal reservoirs to the skin (23) or urethra (5) were reinvestigated 3 years after the first measurement. BMD was measured in the lumbar spine, femur and whole body with DXA. Bone specific alkaline phosphatase, osteocalcin, parathyroid hormone (PTH), calcitonin and chloride were also determined in serum. GFR was determined from the plasma clearance of 51Cr-EDTA. The mean values for BMD expressed in percentage of corresponding mean values for age-matched controls (BMD%) were almost identical after 3 years. Only osteocalcin levels correlated with the BMD% values. However, significant positive correlations were found between GFR and the observed individual changes in BMD% over the 3 years in spite of the fact that most GFR values were fairly normal. Enhanced bone loss was associated with high concentrations of osteocalcin and bone specific alkaline phosphatase. Comparisons with blood gas analyses and determination of 1,25 dihydroxyvitamin D performed in the previous study indicate to us that the relation between reduced GFR and low mineral content might, in part, be related to a low-grade metabolic acidosis and reduced availability of the biologically active vitamin D hormone. The conclusion to be drawn is that urinary diversion with a Kock reservoir does not regularly cause bone demineralization. However, patients with even moderately reduced GFR appear to be at risk for developing osteoporosis in the long-time run.

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.

Concrement formation and urease-induced crystallization in urine from patients with continent ileal reservoirs.

OBJECTIVES: To study the relationship between urinary tract infection, urine composition and concrement formation in patients with continent ileal reservoirs for urinary diversion. PATIENTS AND METHODS: The study comprised 27 patients (seven men and 20 women, mean age 47 years, range 23-76) with continent ileal reservoirs who were followed for a mean of 67 months (range 13-146) by annual reservoiroscopy, intravenous urography and urine culture; at the final follow-up, a sample of their morning urine was analysed for a range of compounds and the number and size of any particles present or produced in response to incubation with urease. RESULTS: The presence of urease-producing bacteria was associated with the formation of concrement. However, a few patients in whom an infection with urease-producing organisms was not detected also formed concrement. Urine from those patients forming stones tended to have a high calcium and a low citrate concentration. After incubation with urease, significantly more and larger particles were formed in the urine from stone formers. There was a strong correlation (r = 0.8) between urinary calcium content and urinary pH when the urease-induced precipitation commenced, and between urinary calcium and the size and volume of the crystals developed (r = 0.9) after 4 h of incubation. CONCLUSIONS: There are many factors which might influence the formation of concrement, e.g. outflow conditions, the presence of staples or infection in the reservoir, and the composition of the urine is also important. It thus appears appropriate to determine if measures to reduce urinary calcium and increase urinary citrate can decrease the episodes of stone formation in those patients with continent ileal reservoirs for urinary diversion who frequently form stones.

Mucosal permeability of ileal and colonic reservoirs for urine.

OBJECTIVES: To evaluate the intestinal mucosal permeability in continent reservoirs for urine. PATIENTS AND METHODS: The mucosal permeability in continent urinary reservoirs, constructed either from an ileal or a colonic segment (six patients each), was assessed by analysing serial samples of plasma, after instilling the reservoir with 51Cr-ethylene diaminetetra-acetic acid (51Cr-EDTA), and serum, after instillation with polyethylene glycol (PEG 400). RESULTS: There was no or negligible permeation of 51Cr-EDTA and PEG 400 in either type of reservoir, as there was no significant increase of the markers in plasma and serum, respectively. CONCLUSION: The intestinal barrier to medium-sized hydrophilic molecules seems intact in continent urinary reservoirs. The lack of significant permeation of 51Cr-EDTA confirms the usefulness of a single injection of 51Cr-EDTA for the determination of glomerular filtration rate in patients with intestinal urinary diversion.

Stabilization of the nipple base with titanium rings when reoperating patients with continent urostomies for nipple dysfunction.

Nipple dysfunction in Kock reservoirs used for continent urinary diversion is usually caused by a flattening out of the intestinal nipple due to a lateral tore at the base of the nipple when the reservoir expands. This study describes a new method to repair dysfunctioning nipples based on the use of titanium rings applied outside the reservoir around the base of the nipple. Experiments on dogs and rats have shown that rings and plates of titanium rapidly attach to the serosal surface of ileum exposed to urine with only minor signs of inflammation. Ten patients with Kock reservoirs for urinary diversion have been reoperated for nipple dysfunction due to nipple sliding with elongation of the nipple and fixation of the nipple base with titanium rings. The functional result is excellent in 9 out of the 10 patients. No signs of erosion of the rings into the reservoirs have been noted. With this new method for nipple repair the need for using more intestine to construct a new nipple is eliminated.

Effect of pre-treatment with desferrioxamine and mannitol on radical production and kidney function after ischaemia-reperfusion. A study on rabbit kidneys.

The effects of pre-treatment with mannitol and the iron chelator desferrioxamine on oxygen radical formation and glomerular and tubular function after ischaemia in the rabbit kidney were studied. Radicals were measured with ESR and spin trapping. At reperfusion after 60 min of renal ischaemia there was a significant increase in the production of free radicals in the venous effluent from the kidney. Administration of either mannitol or desferrioxamine given before ischaemia and before recirculation reduced the radical production significantly. The iron chelator appeared to be more effective. Glomerular function measured 48 h after reperfusion was significantly better after pretreatment with desferrioxamine and mannitol compared with mannitol alone. Tubular function did not differ between the two pre-treatment groups.

Bacteriuria in patients with a continent ileal reservoir for urinary diversion does not regularly require antibiotic treatment.

OBJECTIVE: To elucidate the importance of bacteriuria in patients with a continent urinary diversion. PATIENTS AND METHODS: Eighteen asymptomatic patients (16 women and two men, with a mean age of 53 years [range 22-73]) with ileal reservoirs coupled to the skin for urinary diversion were studied. Consecutive urine cultures were performed over 5 months. Concomitant measurements of antibody titres against Escherichia coli and Proteus, and C-reactive protein (CRP) values were made. RESULTS: The results of the urine cultures varied considerably between samples. Increased titres of antibodies against E. coli were seen in several patients but the correlation with bacteriuria caused by E. coli was weak (sensitivity 33%, specificity 56%). Increased titres of antibodies against Proteus were rarely seen and in no patient correlated with bacteriuria caused by Proteus. Increased levels of CRP were seen in three patients. CONCLUSION: The present results indicate that asymptomatic bacteriuria in patients with a continent ileal reservoir for urinary diversion is generally of no clinical importance and should not be treated with antibiotics. This conclusion is based on the observations that the bacterial strains growing in the reservoir changed spontaneously indicating colonization rather than infection. Raised titres of antibodies against E. coli correlated weakly with bacterial growth. The observed elevations in antibody titres were usually just above the normal upper limit.

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

Ten patients with a continent ileal reservoir for urinary diversion were studied regarding transmucosal fluxes of water and electrolytes at different pH. The urine was by-passed the reservoir via a Foley catheter. The experiment set-up was designed to exclude urine from reservoir mucosa exposition during the study. Test solutions of pH 4 and pH 7 with electrolytes and a non-absorbable volume marker (PEG MW 4000) were instilled into the empty reservoir. The influence of altered pH on the flow of water and Na,+K+ and Cl- across the reservoir mucosa was analysed. The maximal concentration ability after intranasal desmopressin (Minirin), the creatinine and Na-clearance as well as the fractional Na-excretion were calculated from measurements on the by-passed urine. The results showed a secretion of water, Na+ and Cl- into the reservoir while the K+ content was constant. The mucosal flows of water and electrolytes were not affected by alterations in reservoir pH. Maximal concentration ability appeared to be reduced compared to normals. Fractional Na excretion was within normal limits.

Absorption of sodium and chloride in continent reservoirs for urine: comparison of ileal and colonic reservoirs.

The absorptive capacity of urinary reservoir mucosa was studied by measuring the fractions of 22sodium and 36chloride absorbed after instillation into reservoirs constructed from an ileal or a colonic segment. The absorption of 22sodium did not differ between the 2 reservoir types but absorption of 36chloride was greater in the colonic reservoirs. The levels of chloride in serum were significantly higher in patients with a colonic than in those with an ileal reservoir. In the ileal reservoirs the absorptive capacity was greater for 22sodium than for 36chloride.

ESR-measurement of oxygen radicals in vivo after renal ischaemia in the rabbit. Effects of pre-treatment with superoxide dismutase and heparin.

The effects of intracellular and extracellular superoxide dismutase and heparin administration on oxygen radical formation after ischaemia in the rabbit kidney were studied. Radicals were measured with ESR and spin trapping. At reperfusion after 60 min of renal ischaemia there was a significant increase in the production of free radicals in the venous effluent from the kidney. Administration of either intracellular superoxide dismutase or extracellular superoxide dismutase before ischaemia and before reperfusion prevented approximately 85% of the radical formation seen in the untreated control group. Administration of heparin 5 min before recirculation resulted in a 65% decrease in radical production compared to the control group.

ESR-measurement of production of oxygen radicals in vivo before and after renal ischaemia in the rabbit.

This study describes a spin trap technique to determine production of oxygen radicals in rabbit kidneys after ischaemia and reperfusion. OXANOH was infused intra-arterially. When exposed to oxygen free radicals OXANOH is oxidized to the stable radical OXANO(.). The concentration of OXANO. in samples of renal venous blood was determined by ESR. Production of oxygen radicals was calculated from the amount of OXANO. in the venous blood and the blood flow which was determined by an ultrasound technique. The radical production at reperfusion after ischaemia was expressed as a per cent of the pre-ischaemic value. A drastic increase in radical production was observed during (60 min) reperfusion after 60 min of ischaemia. Pretreatment with oxypurinol (20 mg kg-1) before ischaemia and before recirculation almost completely abolished the rise in radical production at recirculation. Similar results were obtained when oxypurinol was given before recirculation only.

Significance of the antireflux valve for upper urinary tract pressure. An experimental study in patients with urinary diversion via a continent ileal reservoir.

When bladder substitution is required, a low pressure receptacle and an antireflux valve with low resistance to flow is essential for preservation of the upper urinary tract. The aim of this study was to evaluate whether these criteria are attained in the continent ileal reservoir used for urinary diversion. The investigations were performed in six patients more than one year after supravesical urinary diversion via a continent ileal reservoir. The pressure was recorded simultaneously both in the afferent loop and in the reservoir during filling of the reservoir. There was a slow parallel increase in the basal pressure in the reservoir and the afferent loop. Pressure waves appeared sometimes simultaneously and sometimes in only one compartment at a time. Only during short periods of time did the pressure exceed 25 cm of water. The frequency of pressure waves increased with increased filling of the reservoir. The "total pressure" was larger in the reservoir than in the afferent loop. It is the antireflux valve which prevents pressure rises in the reservoir from being conveyed to the upper urinary tract. The resistance to urinary flow was moderate.

Pregnancy and delivery in patients with urinary diversion through the continent ileal reservoir.

The social and psychologic sequelae after external urinary diversion are known to be fewer in patients with urinary diversion through the continent ileal reservoir (Kock pouch) compared with those with diversion through the incontinent ileal conduit. Therefore, in young female patients treated surgically with urinary diversion through the continent ileal reservoir, a number of pregnancies can be expected. We report herein the results of four pregnancies in three women with this type of reservoir. All deliveries were vaginal. One patient showed urinary obstruction at the end of the pregnancy and delivery was induced. This particular infant was treated with phototherapy because of hyperbilirubinemia; the other three infants were mature. No damage to renal function was noted and revisional surgical treatment of the reservoir was not necessary in any. Consequently, pregnancy is not contraindicated after urinary diversion through the continent ileal reservoir (Koch pouch).

Decreased absorption of 22Na and 36Cl in ileal reservoirs after exposure to urine. An experimental study in patients with continent ileal reservoirs for urinary or fecal diversion.

After urinary diversion to intestinal segments, reabsorption of chloride, ammonium, and hydrogen ions occurs, sometimes leading to hyperchloremic acidosis. The mucosa of ileal reservoirs exposed to urine show substantial atrophy, indicating a loss of absorptive capacity. In ten patients with urinary diversion via a continent ileal reservoir, the absorption of [22Na] and [36Cl] was studied after instillation for 15 min into the reservoir of a test solution containing 50 kBq [22Na] and 50 kBq [36Cl]. The activity of the radionuclides was determined in serum samples after 60 and 180 min and the fractions absorbed were calculated. Absorption of the two radionuclides was also calculated by comparison of the activities in samples of the test solution taken before and 15 min after instillation into the reservoir. The same investigations were performed in seven patients with continent ileostomy reservoirs. The study demonstrated a decreased capacity to absorb [22Na] and [36Cl] across the mucosa of the reservoirs exposed to urine compared to the mucosa of those exposed to feces. Due to the transformation of the ileal mucosa after exposure to urine, the risk for development of metabolic disturbances should be minimal after urinary diversion to a continent ileal reservoir.

Renal function and upper urinary tract configuration following urinary diversion to a continent ileal reservoir (Kock pouch): a prospective 5 to 11-year followup after reservoir construction.

We followed 17 patients who underwent urinary diversion via a continent ileal reservoir (Kock pouch) with yearly examinations for 5 to 11 years postoperatively. The examinations involved control of renal function and configuration of the upper urinary tract. In 5 patients the upper urinary tract had become dilated during followup and in 2 of these renal scarring also had developed. All 5 patients had endured temporary outflow obstruction or reflux (stricture, overdistension of the reservoir or a defective antireflux valve). Of the patients 1 had a marked decrease in renal function before the outflow obstruction was corrected by an operation. Routine blood chemistry study was normal and hyperchloremic acidosis was not noted in any patient. After peroral loading of 6 patients with ammonium chloride significant excretion of titratable acid was found in the urine. Substitution with vitamin B12 was given to 6 patients due to subnormal values in 2 and borderline values in 4.

Voiding pattern, urinary volume, composition and bacterial contamination in patients with urinary diversion via a continent ileal reservoir.

A series of 41 patients with a continent ileal reservoir for urinary diversion (Kock pouch) was studied with regard to voiding pattern (voiding frequency), voided volume, urinary composition, bacterial contamination and mucus secretion. The mean voiding frequency in 21 patients was 5/24 h and the time required for the procedure, including the time to cover the stoma with a bandage, was 3 to 5 min; 2 patients voided once or twice at night, while 19 patients never did so. The mean volume voided during the day were significantly smaller than the volume voided in the morning. The total 24-h urinary volume exceeded that of normal individuals but the 24-h secretion of electrolytes was within normal limits. Bacterial contamination was found in most samples of urine. Evacuation was not impeded by the rich mucus content of the urine and mucus production did not diminish with time.

Urinary diversion via the continent ileal reservoir. Functional characteristics and long-term outcome.

The aim of the present investigation was to study the functional characteristics and the long-term outcome after urinary diversion via a continent ileal reservoir. The villus height and absorptive capacity of ileal mucosa were studied in cats after exposure of the ileal mucosa to urine. In 16 patients at various intervals after their reservoir construction, the absorptive rate of L-phenylalanine was estimated after instillation of a test solution into the reservoir. The influence of the reservoir pressure was studied in 13 patients with empty and full reservoirs. The reservoir pressure was registered during renography and the volume recovered from the reservoir was measured. Twenty-one patients registered their emptying patterns and their emptying volumes during seven 24-hour periods. Urine samples were taken for determination of electrolytes (Na+, K+, Cl-), osmolality, pH and possible bacteriuria. Mucus in the urine was measured at various postoperative time intervals. Seventeen patients were followed postoperatively with a yearly determination of renal function and urography in special reference to the upper urinary tract. Routine blood tests, vitamin B12 in serum and base excess were also determined. In six patients, the excretion of titratable acid was determined after peroral loading with ammonium chloride. After exposing ileal mucosa to urine in cats, a significant decrease was found in the villus height and the absorption of water and electrolytes. This was true for the isotonic test solution but not for the hypertonic solution. The rate of active absorption of L-phenylalanine from the patient reservoirs decreased with the postoperative interval. With ordinary filling volumes, the pressure in the reservoir did not interfere with upper urinary tract drainage. The patients emptied their reservoir with a frequency similar to that of the voiding frequency of normal individuals. The 24 h volume was somewhat increased but the excretion of electrolytes and osmoles was normal. Bacteriuria was often present but, as long as reflux was prevented, it seemed to be of no harm. Mucus production did not diminish with time. Long-term follow-up (5-11 years) of renal function and upper urinary tract configuration disclosed that deterioration is infrequent and occurs only as a consequence of reflux or obstruction to flow. No metabolic disturbances have occurred.

Absorption of L-phenylalanine in human ileal reservoirs exposed to urine.

The mucosa of ileal reservoirs exposed to urine undergoes successive structural changes, indicating a loss of absorptive capacity. In patients with urinary diversion via a continent ileal reservoir, the active absorption of L-phenylalanine from the reservoir was studied at different postoperative time intervals. A test solution containing L-phenylalanine was instilled into the reservoir and samples were taken at intervals during a period of one hour for determination of phenylalanine. In one group of patients, urine from the kidneys by-passed the reservoir via a catheter inserted into the afferent segment. Within three months after construction of the ileal reservoir, the uptake was significantly slower than that in ileostomy reservoirs and the absorption decreased even more with longer observation times. Mixing of urine with the reservoir contents did not influence the uptake of L-phenylalanine to any significant degree. The reduced absorption of L-phenylalanine indicates that the uptake of other substances from this type of ileal reservoirs might be decreased also.

Drainage of the upper urinary tract as recorded with renography in patients with a continent urostomy (Kock pouch). An experimental study with various degrees of reservoir filling.

The drainage from the upper urinary tract was studied by the use of renography in thirteen patients with well functioning continent ileal reservoirs for urinary diversion (Kock-pouch). Renography was performed with empty reservoir and with submaximal or maximal filling of the reservoir. The reservoir pressure was continuously recorded when renography was performed with a full reservoir. When the reservoir was empty renography showed normal drainage in all patients. When the reservoir was full the renography was normal in eight patients, these having a mean reservoir volume of 715 ml but showed a delay in five patients, these having a mean reservoir volume of 930 ml. When the renography was repeated in the latter group of patients with submaximal filling (mean reservoir volume 544 ml) there was no delay of the drainage phases on the renograms. In these five patients the considerable "over-filling" of the reservoir had resulted in volumes greatly exceeding the previously recorded maximal reservoir capacity and also in pressures exceeding considerably those usually recorded in ileal reservoirs. These results show that the pressure in the bladder substitute is of great significance for the drainage from the upper urinary tract and that the low pressure ileal reservoir under ordinary circumstances does not obstruct the flow from the upper urinary tract.