Electrolyte and acid base imbalance in patients with rectosigmoid bladder

Outcome of complete primary bladder exstrophy repair: single-center experience

OBJECTIVE

Reconstruction of bladder exstrophy remains a challenge. We evaluated our experience with complete primary repair in classic bladder exstrophy.

METHODS

A retrospective data review was conducted of bladder exstrophy patients presenting at our institution between May 2000 and September 2007. Fifty-one patients (21 females and 30 males) with classic bladder exstrophy were included. Age of presentation ranged from 24h to 14 months. Mean follow up was 3 years (1 month-7 years). Patients were evaluated for continence, upper tract dilatation and cosmetic result.

RESULTS

Eight patients (15.6%) had failed closures and six (11.7%) had fistulae. Evaluation of continence excluded 16 patients not followed up at our center. Thirty-seven percent were continent on clean intermittent catheterization after the age of 5 years. Patients became dry only after augmentation cystoplasty. Upper tract changes were mild during our study with all patients having normal serum creatinine.

CONCLUSION

Patients may require more than one procedure for reconstruction. In our series, augmentation was required to achieve acceptable dryness. Early promising results with dry intervals in young patients did not translate to continence in older patients.

Endoscopic management of obstructive complications in ureterosigmoidostomy

OBJECTIVES

Although rarely used today for supravesical urinary diversion, ureterosigmoidostomy remains useful in patients with bladder exstrophy. However, management of ureteral stricture and ureteral urolithiasis is challenging because of the lack of anatomic landmarks.

METHODS

We reviewed our prospectively collected database from 1994 to 2006 for all patients requiring surgical treatment for obstructive complications associated with ureterosigmoidostomy.

RESULTS

Our analysis revealed 3 patients (mean age 46 years; 2 men and 1 woman). All 3 patients had undergone ureterosigmoidostomy as a component of bladder exstrophy management. All patients presented with renal failure due to obstruction and required antegrade endoscopic management. Two patients had anastomotic strictures and one had obstructive urolithiasis. One patient in whom the stricture was judged to be chronic was treated with an endoureterotomy and Acucise balloon. The second patient, who had an acute obstruction after colonoscopic biopsy of his anastomosis, was treated with antegrade balloon dilation. Both patients had stents placed across the anastomosis for 6 weeks postoperatively. Despite reflux of stool into the collecting system, neither patient manifested with local or systemic signs of infection. The patient with urolithiasis required antegrade basket stone extraction.

CONCLUSIONS

Obstructive complications after ureterosigmoidostomy should be managed using antegrade endoscopic techniques.

Complete repair of bladder exstrophy: preliminary experience with neonates and children with failed initial closure

PURPOSE

The surgical repair of bladder exstrophy remains challenging for the pediatric urologist. We present our preliminary experience with complete primary repair of exstrophy in neonates and children with failed initial closure.

MATERIALS AND METHODS

Between November 1998 and April 1999, 9 boys and 2 girls with bladder exstrophy underwent complete repair. This procedure was performed in the first 72 hours of life in 4 boys and at age 3 months in 1 girl. Complete repair with osteotomy was performed after failed initial closure in 5 boys and 1 girl at a mean age of 28 months (range 15 to 36). The bladder and urethra were closed in continuity and epispadias was repaired by total penile disassembly. All patients were kept in a spica cast for 3 weeks. Ureteral stents and suprapubic tube were removed 10 and 14 days, respectively, after surgery. Ultrasound was performed preoperatively and every 3 months postoperatively, voiding cystourethrography was done 6 to 12 months after surgery.

RESULTS

Mean followup is 14 months (range 12 to 17). All repairs were successful including 1 case of penile scrotal duplication. Concomitant augmentation was done in 2 girls due to a small bladder plate. Complete closure resulted in hypospadias in 3 of the 9 boys. No patient had dehiscence or fistula. Serial followup ultrasound revealed no hydronephrosis and normal renal growth. Febrile urinary tract infection occurred in 1 case 2 months after surgery and was managed conservatively. Bladder capacity was 200 and 270 ml., at 6 months, respectively, in the 2 patients with an augmented bladder and both are dry on intermittent catheterization. The 4 patients in whom the closure was performed at birth are voiding with dry intervals with mean bladder capacity of 75 cc at 1 year (range 60 to 90). The 5 older children had a mean bladder capacity of 120 cc (range 70 to 150) at 6 months, of whom 2 are completely continent and 3 have 1 to 3 hours of dry intervals.

CONCLUSIONS

Complete repair of bladder exstrophy is feasible in neonates and children after failed initial closure with minimal morbidity. There is no short-term evidence of worsening reflux or hydronephrosis. Longitudinal followup with adequate recording is required for continence evaluation. This technique may minimize the future need of bladder neck reconstruction and augmentation in patients with exstrophy.

Long-term outcome analysis of low pressure rectal reservoirs in 33 children with bladder exstrophy

PURPOSE

The augmented valved rectum and double folded rectosigmoid bladder represent 2 modifications of ureterosigmoidostomy. Both procedures improve continence by lowering the reservoir pressure. We present the outcome of these techniques on the upper urinary tract, continence, metabolic profile, linear growth and bone density.

MATERIALS AND METHODS

Between March 1987 and May 1997, 22 boys and 11 girls with bladder exstrophy underwent urinary diversion to a low pressure rectal reservoir. Patient age at surgery ranged from 2 to 13 years (mean 5.4). The augmented valved rectum technique was used in 18 cases and the double folded rectosigmoid bladder method was used in 15. Serial followup ultrasounds were obtained and voiding proctography was performed 1 year postoperatively in all patients. Supine height was measured at last followup in all cases. Serum electrolytes, arterial blood gases, the results of which were plotted on an acid base nomogram, and bone density using dual energy x-ray absorptiometry were measured in all patients. Prophylactic alkalization was administered to all patients.

RESULTS

Mean followup is 66 months (range 24 to 148). All patients are continent during the daytime with an emptying frequency of 3 to 5 times, and all are continent at night. No patient experienced pyelonephritis or clinical acidosis. The upper urinary tract was either improved or stabilized in 64 of 66 renal units. No patient had reflux to the upper urinary tract. All patients had normal serum creatinine, sodium, potassium, calcium and phosphorus. Hyperchloremia was noted in 19 of the 33 patients (57%), and arterial blood gases showed subclinical metabolic acidosis in 18 (55%). Supine height measurements at last followup revealed that 19 of the 33 patients (57%) had decreased linear growth (below 3rd percentile). All patients had significant reduction in bone density, and mean for age corrected bone density was 70% (standard deviation 10.9%). Both groups (augmented valved rectum and double folded rectosigmoid bladder) were comparable in regard to age, sex and followup duration. There was no statistically significant difference between the groups in any parameter measured.

CONCLUSIONS

The augmented valved rectum and double folded rectosigmoid bladder provide preservation of the upper urinary tract with excellent continence rates. However, prophylactic alkalization and functional isolation of the reservoir do not prevent the long-term metabolic consequences. Subclinical metabolic acidosis and decreased linear growth are to be anticipated in more than 50% of patients. Moreover, significant bone demineralization is to be expected in all of these patients.

LONG-TERM OUTCOME ANALYSIS OF LOW PRESSURE RECTAL RESERVOIRS IN 33 CHILDREN WITH BLADDER EXSTROPHY

PURPOSE

The augmented valved rectum and double folded rectosigmoid bladder represent 2 modifications of ureterosigmoidostomy. Both procedures improve continence by lowering the reservoir pressure. We present the outcome of these techniques on the upper urinary tract, continence, metabolic profile, linear growth and bone density.

MATERIALS AND METHODS

Between March 1987 and May 1997, 22 boys and 11 girls with bladder exstrophy underwent urinary diversion to a low pressure rectal reservoir. Patient age at surgery ranged from 2 to 13 years (mean 5.4). The augmented valved rectum technique was used in 18 cases and the double folded rectosigmoid bladder method was used in 15. Serial followup ultrasounds were obtained and voiding proctography was performed 1 year postoperatively in all patients. Supine height was measured at last followup in all cases. Serum electrolytes, arterial blood gases, the results of which were plotted on an acid base nomogram, and bone density using dual energy x-ray absorptiometry were measured in all patients. Prophylactic alkalization was administered to all patients.

RESULTS

Mean followup is 66 months (range 24 to 148). All patients are continent during the daytime with an emptying frequency of 3 to 5 times, and all are continent at night. No patient experienced pyelonephritis or clinical acidosis. The upper urinary tract was either improved or stabilized in 64 of 66 renal units. No patient had reflux to the upper urinary tract. All patients had normal serum creatinine, sodium, potassium, calcium and phosphorus. Hyperchloremia was noted in 19 of the 33 patients (57%), and arterial blood gases showed subclinical metabolic acidosis in 18 (55%). Supine height measurements at last followup revealed that 19 of the 33 patients (57%) had decreased linear growth (below 3rd percentile). All patients had significant reduction in bone density, and mean for age corrected bone density was 70% (standard deviation 10.9%). Both groups (augmented valved rectum and double folded rectosigmoid bladder) were comparable in regard to age, sex and followup duration. There was no statistically significant difference between the groups in any parameter measured.

CONCLUSIONS

The augmented valved rectum and double folded rectosigmoid bladder provide preservation of the upper urinary tract with excellent continence rates. However, prophylactic alkalization and functional isolation of the reservoir do not prevent the long-term metabolic consequences. Subclinical metabolic acidosis and decreased linear growth are to be anticipated in more than 50% of patients. Moreover, significant bone demineralization is to be expected in all of these patients.

Complete repair of bladder exstrophy: preliminary experience with neonates and children with failed initial closure

PURPOSE

The surgical repair of bladder exstrophy remains challenging for the pediatric urologist. We present our preliminary experience with complete primary repair of exstrophy in neonates and children with failed initial closure.

MATERIALS AND METHODS

Between November 1998 and April 1999, 9 boys and 2 girls with bladder exstrophy underwent complete repair. This procedure was performed in the first 72 hours of life in 4 boys and at age 3 months in 1 girl. Complete repair with osteotomy was performed after failed initial closure in 5 boys and 1 girl at a mean age of 28 months (range 15 to 36). The bladder and urethra were closed in continuity and epispadias was repaired by total penile disassembly. All patients were kept in a spica cast for 3 weeks. Ureteral stents and suprapubic tube were removed 10 and 14 days, respectively, after surgery. Ultrasound was performed preoperatively and every 3 months postoperatively, voiding cystourethrography was done 6 to 12 months after surgery.

RESULTS

Mean followup is 14 months (range 12 to 17). All repairs were successful including 1 case of penile scrotal duplication. Concomitant augmentation was done in 2 girls due to a small bladder plate. Complete closure resulted in hypospadias in 3 of the 9 boys. No patient had dehiscence or fistula. Serial followup ultrasound revealed no hydronephrosis and normal renal growth. Febrile urinary tract infection occurred in 1 case 2 months after surgery and was managed conservatively. Bladder capacity was 200 and 270 ml., at 6 months, respectively, in the 2 patients with an augmented bladder and both are dry on intermittent catheterization. The 4 patients in whom the closure was performed at birth are voiding with dry intervals with mean bladder capacity of 75 cc at 1 year (range 60 to 90). The 5 older children had a mean bladder capacity of 120 cc (range 70 to 150) at 6 months, of whom 2 are completely continent and 3 have 1 to 3 hours of dry intervals.

CONCLUSIONS

Complete repair of bladder exstrophy is feasible in neonates and children after failed initial closure with minimal morbidity. There is no short-term evidence of worsening reflux or hydronephrosis. Longitudinal followup with adequate recording is required for continence evaluation. This technique may minimize the future need of bladder neck reconstruction and augmentation in patients with exstrophy.

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.

Flow diagrams for the diagnosis of acid-base disorders

This article discusses flow diagrams and tables intended to provide a systematic approach to the rapid laboratory differential diagnosis of acid-base disorders in the emergency department.

Metabolic complications of urinary diversions: an overview

Patients with urinary diversions present unique challenges to internists who have an important role in their long-term management. Advances in surgical techniques over the past 30 years have given rise to a number of urinary diversion procedures that use various intestinal segments. In its normal function, the intestine absorbs water and solutes. When placed in contact with the urinary stream, the intestine can create numerous metabolic abnormalities. These include bone disease, hepatobiliary disease, infection, malignancy, neurologic complications, nutritional deficiencies, and a number of electrolyte and acid-base disorders. An overview of these metabolic abnormalities and their causes is provided, as well as recommendations for screening and management of patients.

Bone demineralization following urinary intestinal diversion assessed by urinary pyridinium cross-links and dual energy x-ray absorptiometry

PURPOSE

We investigated the acid-base balance and bone mineral status in patients with 3 types of urinary intestinal diversion.

MATERIALS AND METHODS

Of 46 men with urinary intestinal diversions 20 had a Kock pouch, 15 had an Indiana pouch and 11 had an ileal conduit. Acid-base balance was assessed by arterial blood gas analysis. Bone mineral status was measured by urinary pyridinium cross-links and dual energy x-ray absorptiometry. In addition, urinary deoxypyridinoline was measured in 79 patients.

RESULTS

Of the 46 patients 7 (15%) with the Kock pouch (1), Indiana pouch (5) and ileal conduit (1) had metabolic acidosis associated with significantly lower bone mineral densities (p < 0.05) and higher urinary pyridinium cross-links (p < 0.005) than did those with normal acid-base status. No difference was found in metabolic acidosis and bone demineralization among the 3 groups. Additionally, in 79 patients urinary deoxypyridinoline reached the highest level immediately postoperatively and then gradually decreased to the stable level within 1 or 2 years.

CONCLUSIONS

Metabolic acidosis following urinary intestinal diversion results in bone demineralization. The types of diversion did not cause differences in metabolic acidosis and bone resorption. Bone has a major role in buffering acid overload in the early postoperative period.

Metabolic consequences of sigmoidocystoplasty in children

Recent reports have shown that metabolic acidosis is a possible complication in patients who undergo augmentation enterocystoplasty. We studied 30 patients with neurogenic bladder who underwent sigmoidocystoplasty. Follow-up ranged from 1 to 10 years; all the patients showed normal renal function. We found significant hyperchloremic acidosis in 10% and borderline acidosis in 27% of the patients. Abnormalities of calcium and phosphorus balance were noted in 16.5% and 43% of the patients respectively, and more frequently in acidolic patients, which might be the result of activation of the bony buffers and might cause delayed growth in children. Close follow-up of all patients with enterocystoplasty is required, and oral bicarbonate is indicated when acidosis is detected.

Changes in acid-base balance and calcium metabolism after urinary diversion through ileal segments. II. Treatment with nicotinic acid

Investigations in animals have shown that nicotinic acid, an intestinal cyclic-AMP inhibitor, partially corrects the metabolic changes associated with urinary diversion through intestinal segments. Blood and serum chemistry were studied in patients before and 3 to 5 months after undergoing urinary diversion through ileal segments, both with and without nicotinic acid treatment. It was found that diverted patients had metabolic acidosis, an increased anion gap and increased levels of serum alkaline phosphatase; there were no significant changes in serum PTH and vitamin D levels, calcaemia and phosphoraemia. There was a tendency towards dehydration, hypernatraemia, hyperchloraemia and secondary hyperaldosteronism produced by ileal secretion of a hypotonic fluid. Nicotinic acid 3 g/day significantly reduced the chloraemia but did not correct the metabolic acidosis, although it reduced its severity, since blood pH decreased when treatment was suspended. Nicotinic acid cannot be recommended for routine use in the management of metabolic acidosis after urinary diversion, and patients with a marginal renal reserve should not be considered for trans-intestinal urinary diversion.

Urinary solute transport by ileal segments. I. Effects of nicotinic acid

This study was conducted to quantify urinary solute transport by the ileum, using an in vivo human model, and to determine the effect of nicotinic acid on this process. Patients were studied under both basal conditions and niacin therapy. The rates of solute transport were established by analysis of excretion indexes for each solute. Potassium and ammonium were absorbed by the ileum, while phosphorus, sodium and bicarbonate were secreted. The percentage excretion index of sodium and bicarbonate increased by approximately 100 and 600% respectively, causing a significant rise in urinary pH. Although not statistically significant, there was a tendency for chloride to be absorbed and for water to pass into the bowel lumen. Nicotinic acid 3 g/day had no significant effect on urinary solute transport.

Ureterosigmoidostomy

After a brief review of the main ureterosigmoidostomy techniques, the Authors evaluate their own experience based on 116 patients operated between 1969 and 1987. The early and late complications of this procedure have been analyzed, in particular those regarding the state of the upper urinary tracts, hyperchloremic acidosis, colonic neoplasms, renal stones and proctitis. The Authors conclude that ureterosigmoidostomy still seems to have a well-defined role among urinary diversion possibilities that may be offered to patients (in particular women).

Calcium balance, growth and skeletal mineralisation in patients with cystoplasties

Twelve adult female patients and 16 children who had undergone augmentation cystoplasty at least 2 years previously were studied to assess calcium balance and skeletal mineralisation. The serum and 24-h urinary calcium levels were measured and arterial blood gas analysis was performed in all patients. In children, skeletal mineralisation was assessed by serial study of their growth charts, comparing their growth centiles before and after cystoplasty. In adults, skeletal mineralisation was assessed by dual photon absorptiometry (DPA). As previously reported, all patients had a metabolic acidosis, usually with respiratory compensation. Serum and 24-h urinary calcium levels were all within the normal range. Growth charts of the 6 children with colocystoplasties showed an average of 20% reduction in growth potential in 3 of them. Growth charts in the 10 children with ileocystoplasties did not show any change in growth pattern. DPA bone scans in adults were all normal. These results suggest that if calcium is mobilised from bone in patients with a cystoplasty as a result of the metabolic acidosis, then it is reabsorbed from the bladder by the gut segment after an ileocystoplasty; colonic segments are less efficient than ileal segments, however, so that after a colocystoplasty skeletal demineralisation or a reduction in growth potential is more likely.

Abnormalities of colonic mucin secretion and metabolic changes after internal urinary diversion for bladder exstrophy. A prospective study

Ten patients with different types of internal urinary diversion for bladder exstrophy were studied prospectively in order to assess metabolic abnormalities and morphological, histochemical and lectin binding changes in the colorectal mucosa. The histochemical and/or lectin binding changes which were found in the majority of patients were identical to those observed in premalignant and malignant conditions of the colon. In some cases they were detectable 3 years after the initial examination but were completely absent from the colorectal mucosa of normal subjects. Metabolic disturbances (metabolic acidosis, increased anion gap, hyperchloraemia) were observed in a substantial number of asymptomatic patients. These findings stress the need for regular endoscopic, histological and metabolic follow-up in these patients and for life-long treatment with bicarbonate or citrate.

Metabolic complications of cystoplasty

A series of 48 patients with intestinal segments incorporated into the urinary tract underwent assessment of acid-base and electrolyte balance. All patients had abnormal blood gas analyses, usually a metabolic acidosis with respiratory compensation; 33% had hyperchloraemia. Radioisotope studies using sodium, potassium and bromine showed that all were absorbed and that absorption was unaffected by renal function. The results suggest that all such patients, but particularly women and children, may be at risk of the secondary effects of chronic acidosis, especially skeletal demineralisation, unless some compensatory mechanism is working to offset the effects of the acidosis.

Metabolic acidosis after bladder replacement: comparison of severity and reversibility in ileal and colonic reservoirs

Metabolic acidosis developed frequently after ureterosigmoidostomy and rectosigmoid bladder construction but has been reported rarely after the newer methods of continent urinary diversion which also employ intestinal reservoirs. We created an animal model in which to compare the metabolic effects of bladder replacement with segments of ileum or colon and the potential for reversing these derangements with nicotinic acid and chlorpromazine. One year after six dogs' bladders were replaced by colon (three) or ileum (three), all dogs appeared in excellent health and were free of urinary tract obstruction and clinical infection. Both groups of dogs were severely acidotic with diminished arterial pH and arterial and venous total CO2 concentrations although normal serum electrolytes and creatinine concentrations were maintained. Both groups of dogs absorbed approximately one half the urinary sodium, chloride and urea presented to their intestinal reservoirs. After treatment with nicotinic acid and chlorpromazine, the metabolic status of both groups of animals improved. Although nicotinic acid reduced urinary excretion of electrolytes more effectively than chlorpromazine, nicotinic acid was not more effective for reversing metabolic acidosis. When nicotinic acid was provided as an adjunct to sodium bicarbonate therapy in two animals acidosis was corrected at reduced doses of sodium bicarbonate. Based upon this work in an animal model, there does not appear to be a metabolic advantage to intestinal reservoirs which incorporate ileum versus colon. However, asymptomatic patients with normal serum electrolytes and creatinine concentrations may be acidotic. The effects of long term mild acidosis are unknown. However, if therapy is required to prevent diminution of whole body buffers or changes in bone density specific therapy with nicotinic acid or chlorpromazine may reduce the requirement for alkali for correction of metabolic acidosis.

Acid-base disturbances in gastrointestinal disease

Gastrointestinal disorders are associated with severe and often complex acid-base disturbances. We review the most important types of metabolic alkalosis and metabolic acidosis associated with gastrointestinal disorders, excluding liver disease. Special emphasis is placed on pathophysiologic mechanisms. This information may help the clinician understand the generation and maintenance of these disorders and to plan an effective therapeutic approach.