Omeprazole in post-gastrocystoplasty metabolic alkalosis and aciduria

Neurogenic bladder in spinal cord injury patients

Neurogenic bladder dysfunction due to spinal cord injury poses a significant threat to the well-being of patients. Incontinence, renal impairment, urinary tract infection, stones, and poor quality of life are some complications of this condition. The majority of patients will require management to ensure low pressure reservoir function of the bladder, complete emptying, and dryness. Management typically begins with anticholinergic medications and clean intermittent catheterization. Patients who fail this treatment because of inefficacy or intolerability are candidates for a spectrum of more invasive procedures. Endoscopic managements to relieve the bladder outlet resistance include sphincterotomy, botulinum toxin injection, and stent insertion. In contrast, patients with incompetent sphincters are candidates for transobturator tape insertion, sling surgery, or artificial sphincter implantation. Coordinated bladder emptying is possible with neuromodulation in selected patients. Bladder augmentation, usually with an intestinal segment, and urinary diversion are the last resort. Tissue engineering is promising in experimental settings; however, its role in clinical bladder management is still evolving. In this review, we summarize the current literature pertaining to the pathology and management of neurogenic bladder dysfunction in patients with spinal cord injury.

The evolution of bladder augmentation: from creating a reservoir to reconstituting an organ

Bladder augmentation was first described in 1899. The goal at the time was to establish the ideal method to create a simple capacious reservoir for the safe storage of urine. That simple idea has over the last 100 years grown into one of the most dynamic areas in Pediatric Urology. Creative minds and hands from individuals in multiple disciplines have led us from creating a reservoir to the threshold of recreating a functional organ. In this review, we look at the historical evolution of bladder augmentation and how it exponentially grew in scope from those initial descriptions of intestinocystoplasty to the work being reported today in the field of tissue engineering.

Dysfunction of the lower urinary and distal gastrointestinal tracts in pediatric patients with known spinal cord problems

Destruction of the urinary tract in children with elimination, storage, and holding dysfunction of the lower urinary and the distal GI tracts is caused primarily by high intravesical pressure. UTI accelerates this process. The LPP and the status of the urethral control mechanism and its relationship to the detrusor are the primary determinants of intravesical pressure. Intravesical pressures of more than 40 cm H2O are dangerous because they cause a pressure gradient that is transmitted proximally to the renal papillae, which results in the cessation of renal blood flow and a loss of renal function over time. Hydroureteronephrosis, VUR, UTI, urinary incontinence, and calculi formation also may occur. If these dangerously high intravesical pressures remain untreated, renal failure is likely to occur over time. These children then require dialysis or renal transplantation to survive, which is tragic and represents an enormous economic cost to society. Renal failure and upper urinary tract damage is nearly 100% preventable with early and appropriate evaluation and treatment. CIC is a crucial part of the management of these children and has been shown to be safe and effective, even in newborn boys. The use of the Credé maneuver (i.e., manual compression) to empty the bladder is obsolete and should be abandoned. The distal GI tract is inseparable from the lower urinary tract and must be treated simultaneously. Failure to treat the distal GI tract yields poor clinical results and much patient dissatisfaction and makes it difficult or impossible to treat the child's urinary tract problem successfully. Bowel-management programs must include daily high water and fiber intake, together with digital perianal stimulation or fecal extraction. Neuropathic bladder and bowel problems that are intractable to conservative medical and mechanical (i.e., CIC and digital perianal stimulation or fecal extraction, respectively) management almost always can be corrected surgically with high success rates in cooperative patients. Finally, neuropathic bladder and bowel problems can be extremely isolating and debilitating problems. Psychologic counseling and emotional support must be provided as needed. The care that these patients receive must be organized, comprehensive, and correlated with these patients' lifestyles. If these children are evaluated and treated early, they have the potential to live long, healthy, and productive lives.

An original technique for bladder autoaugmentation with protective abdominal rectus muscle flaps: an experimental study in rats

BACKGROUND

Bladder autoaugmentation uses partial detrusorectomy to create a diverticular bulge in the bladder mucosa. This technique has eliminated certain serious complications of cystoplasty with gastrointestinal tissues (e.g., fluid/electrolyte/acid-base imbalances, mucous hypersecretion), but the exposed mucosa is subject to fibrosis and, sometimes, to perforation, which can annul the benefits of surgery.

METHODS

We have developed an original technique based on traditional autoaugmentation with protection of the herniated mucosa by split-thickness pedunculated rectus abdominis muscle flaps that are sutured to the incised margins of the detrusor. Preliminary testing was done on 30 adult Wistar rats. A control group of 15 rats underwent laparotomy alone. Bladder capacity was measured via suprapubic cystography before and after (4 weeks, 8 weeks, 1 year) surgery, just before sacrifice. Sections of the reconstructed bladder were examined histologically.

RESULTS

Twenty-three bladder-augmented rats and 13 controls survived. In the experimental group, bladder capacity increased by 38% (mean). None of the rats experienced urinary retention, although one developed bladder stones. Histology revealed no pathologic changes (other than chronic inflammatory infiltrates at suture sites) in the mucosa, detrusor, or muscle flaps, which were all viable and well integrated by the fourth postoperative week. There were no signs of mucosal or muscle fibrosis.

CONCLUSIONS

Preliminary results in a rat model suggest that this new technique can produce an enlarged bladder that is fully functional and less vulnerable to fibrotic retraction and rupture. Residual contractility in the muscle flaps might theoretically be exploited to facilitate paraphysiologic micturition.

Gastrocystoplasty and chronic renal failure: an acid-base metabolism study

PURPOSE

To verify in an experimental model whether gastrocystoplasty may protect patients with chronic renal failure from acid loading associated acidosis a wedge-shaped portion of the middle stomach was used to improve bladder capacity in animals with chronic renal failure.

MATERIALS AND METHODS

An experimental model was used to study 112 adult female Wistar rats (EPM-1) weighing between 156 and 259 gm. The animals were randomly assigned to groups, including 41 controls, 24 undergoing five-sixths nephrectomy to create chronic renal failure, 26 undergoing gastrocystoplasty and 21 undergoing gastrocystoplasty and five-sixths nephrectomy to create renal failure. To provide an acid overload a 5% NH(4)Cl diet was administered to a subgroup of each group. Two months after surgery 24-hour urine was collected, and volume and pH were measured as well as the amount of bicarbonate, ammonium, titratable acidity and chloride. The animals were then exsanguinated through an abdominal aorta puncture. The blood was used for blood gas analysis and to measure sodium, potassium, chloride, ionized calcium and creatinine.

RESULTS

When undergoing an acid overload, the animals with gastrocystoplasty had no acidosis since acid radicals were eliminating in the urine as NH(4)Cl. When given the same acid overload, metabolic acidosis developed in the animals with gastrocystoplasty and chronic renal failure.

CONCLUSIONS

Gastrocystoplasty protected healthy rats from acidosis when they were given an acid overload but failed to protect the rats with chronic renal failure under the same conditions.

Gastrinaemia and G-cell density in the antral gastrocystoplasty: an experimental study in rats

OBJECTIVE

To evaluate gastrinaemia and G-cell density in the antrum incorporated into the bladder of rats after antrocystoplasty. Materials and methods Thirty-two adult, female Wistar EPM-1 rats (body weight 200-220 g) were divided into four equal groups that underwent; group 1, no treatment (controls); group 2, a sham operation; group 3, antrectomy; and group 4, antrocystoplasty. The rats were assessed 2 months after treatment, and gastrinaemia and the G-cell density determined in the antrum mucosa incorporated into the bladder.

RESULTS

Compared with group 1, serum gastrin was significantly lower in group 3 (P<0.05) and the G-cell density lower in group 4 (P<0.05), although there was no decrease in gastrinaemia in group 4.

CONCLUSION

Antrocystoplasty in rats did not affect gastrinaemia but reduced the number of G cells in the antrum incorporated into the bladder.

The gastrointestinal composite urinary reservoir in patients with myelomeningocele and exstrophy: long-term metabolic followup

PURPOSE

We investigated the long-term metabolic effects of gastrointestinal composite urinary reservoirs in patients with myelomeningocele or exstrophy.

MATERIALS AND METHODS

Seven patients with myelomeningocele or exstrophy who required complex urinary reconstruction in the setting of metabolic acidosis or the short bowel syndrome underwent construction of a gastrointestinal composite reservoir, including a staged and a single procedure in 3 and 4, respectively. Preoperatively and postoperatively serum electrolytes were measured, and urinalysis and urine cultures were performed in all patients. In 5 patients serum pH was compared preoperatively and postoperatively, and in all serum gastrin was measured postoperatively.

RESULTS

At an average followup of 62 months (range 52 to 87) serum chloride and bicarbonate significantly normalized (p <0.05) in all 7 patients with bladder exstrophy or myelomeningocele. Serum pH also significantly normalized (p <0.05) in 5 patients at long-term followup. Serum gastrin and creatinine were normal and urinary pH fluctuated insignificantly throughout followup. None of the patients had urolithiasis or symptoms of the hematuria-dysuria syndrome. Periodic symptomatic urinary tract infections developed but none required chronic antibiotic therapy.

CONCLUSIONS

Gastrointestinal composite urinary reservoirs appear to be beneficial for patients with myelomeningocele or exstrophy who have preexisting metabolic acidosis or the short bowel syndrome. Serum electrolyte neutrality is achieved during long-term followup. No patient had the hematuria-dysuria syndrome or urolithiasis.

The gastrointestinal composite urinary reservoir in patients with myelomeningocele and exstrophy: long-term metabolic followup

PURPOSE

We investigated the long-term metabolic effects of gastrointestinal composite urinary reservoirs in patients with myelomeningocele or exstrophy.

MATERIALS AND METHODS

Seven patients with myelomeningocele or exstrophy who required complex urinary reconstruction in the setting of metabolic acidosis or the short bowel syndrome underwent construction of a gastrointestinal composite reservoir, including a staged and a single procedure in 3 and 4, respectively. Preoperatively and postoperatively serum electrolytes were measured, and urinalysis and urine cultures were performed in all patients. In 5 patients serum pH was compared preoperatively and postoperatively, and in all serum gastrin was measured postoperatively.

RESULTS

At an average followup of 62 months (range 52 to 87) serum chloride and bicarbonate significantly normalized (p <0.05) in all 7 patients with bladder exstrophy or myelomeningocele. Serum pH also significantly normalized (p <0.05) in 5 patients at long-term followup. Serum gastrin and creatinine were normal and urinary pH fluctuated insignificantly throughout followup. None of the patients had urolithiasis or symptoms of the hematuria-dysuria syndrome. Periodic symptomatic urinary tract infections developed but none required chronic antibiotic therapy.

CONCLUSIONS

Gastrointestinal composite urinary reservoirs appear to be beneficial for patients with myelomeningocele or exstrophy who have preexisting metabolic acidosis or the short bowel syndrome. Serum electrolyte neutrality is achieved during long-term followup. No patient had the hematuria-dysuria syndrome or urolithiasis.

Gastric pouch acid secretion in response to physiologic digestive function

OBJECTIVES

To evaluate acid secretion and histologic features of the gastric segment used for bladder replacement in bladder cancer.

METHODS

Nine patients were investigated a mean of 36 months after gastric pouch surgery with modified shamfeeding and feeding. We determined urinary acidity, urinary pH, serum gastrin, and serum pancreatic polypeptide values and tried to find a relationship between feeding and acid secretion in the gastric pouch. In 6 patients, biopsy and histopathologic examination were performed.

RESULTS

In 8 patients, urinary acidity increased after feeding following the rise of gastrin; in 1 patient no increase of gastrin or acidity was observed. In 7 patients, urinary acidity did not change after modified shamfeeding, indicating vagal denervation after surgery. This group showed a minimal urinary pH of above 4 after feeding. On the other hand, in 2 patients an increased acid secretion was observed after modified shamfeeding, indicating the possible presence of residual vagal innervation. In this group, the acid secretion in the pouch was higher, reaching the minimal pH level earlier after feeding. Histopathologic examination showed no major structural changes of gastric mucosa.

CONCLUSIONS

Most patients are vagally denervated after gastric pouch surgery, and the gastric segment continues its original gastrointestinal function by a hormonal pathway. Our data indicate, however, that in some patients, the gastric pouch keeps a residual vagal innervation. We therefore suggest that nerve fibers present in the blood supply of the gastric segment be interrupted to avoid the complications associated with increased acid secretion of the gastric pouch.

Functional outcome and specific complications of gastrocystoplasty for failed bladder exstrophy closure

PURPOSE

The encouraging initial results of gastrocystoplasty led us to perform it for failed bladder exstrophy closure. We assess the functional outcome of the augmented bladder and evaluate complications related directly to use of the stomach in this specific group of children.

MATERIALS AND METHODS

We performed gastrocystoplasty in 22 children an average of 9.5 years old with a small, poorly compliant bladder after staged reconstruction of bladder exstrophy failed. Followup ranged from 6 months to 6 years (mean 3 years).

RESULTS

Complete urinary continence was achieved in 14 children (64%). Voiding via the urethra was possible in 13 patients (60%) but post-voiding residual urine was significant in 12. Bladder capacity increased from a mean of 77 to 270 ml. Bladder capacity decreased during followup in 3 children, requiring repeat augmentation. Six children had isolated dysuria and 2 had dysuria with hematuria. Perforation of the gastric patch and a bleeding gastric ulcer occurred in 1 patient each.

CONCLUSIONS

The disadvantages of gastrocystoplasty outnumber its advantages after failed bladder exstrophy closure. Urethral sensation makes dysuria a major discomfort. Safety is not optimal, since perforation may occur. Voiding is not efficient because gastrocystoplasty provides continence only when it is associated with intermittent catheterization. Bladder capacity is insufficiently augmented and inconsistent during followup. We believe that the use of gastrocystoplasty in cases of failed bladder exstrophy closure should be reconsidered.

Seromuscular gastrocystoplasty in rats

Long-term results of seromuscular gastrocystoplasty have not been reported in the literature. In the presented study, a seromuscular gastrocystoplasty technique in rats and related biochemical, physiological, and histopathologic results are discussed. Fifty rats were grouped as follows: control and sham (group A), animals with gastrocystoplasty (group B), and animals with seromuscular gastrocystoplasty (group C). Urine pH, blood pH, and bicarbonate levels, bladder capacity, and end filling pressures were evaluated in all groups. After gastrocystoplasty and seromuscular gastrocystoplasty both group B and C showed a statistically significant increase in bladder capacity. Aciduria developed in 22% of rats in group B. In group A and C aciduria was not noted. No statistically significant difference was observed in blood pH, bicarbonate levels, and end-filling pressure measurements in each group of rats. Significant histopathologic changes of bladder occurred in the gastrocystoplasty group. In the 13 bladders examined histologically in group B, 2 had a papilloma on the mucosal surface of the transplanted gastric patch. The bladder mucosa adjacent to the transplanted gastric patch had pronounced hyperplastic and squamous metaplastic changes. In the 15 bladders examined histologically in group C none had a papilloma on the gastric segments. Squamous metaplasia in the bladder mucosa adjacent to the transplanted gastric patch was noted only in 2 rats of this group. Two rats also had bladder calculi in the lumen. Possible etiologies and differences of gastrocystoplasty and seromuscular gastrocystoplasty related pathological changes between two groups are discussed.

The use of gastrocystoplasty in patients with bladder exstrophy

The authors report the use of a stomach segment vascularized via the right gastroepiploic artery in order to increased bladder capacity in 18 patients with bladder exstrophy. The morphological and functional results were good in 15 patients (83.4%); 13 (72.2%) continue to use intermittent catheterization to empty the bladder, while 5 (27.7%) have spontaneous voiding. Seven patients are completely continent, 8 partially continent (<3 h), and 2 are still incontinent. We encountered no metabolic complications and no patient complained of mucus production. Ten patients had a dysuria-hematuria syndrome, 8 only slight and 2 marked. We believe that even though gastrocystoplasty is a valid alternative compared with other tissues used to date for bladder augmentation, attention should be paid to this new pathological sequela, which has proved to occur quite frequently, as seen from the long- and short-term follow-up of patients who have had this operation.

Hypergastrinemia following gastrocystoplasty in rats

Gastrocystoplasty has been previously described as an effective method of bladder augmentation or replacement. Twenty-four female Wistar rats were divided into three groups of eight animals each: control (G1), partial gastrectomy with the gastric body (G2) and gastrocystoplasty with the gastric body (G3). The period of observation was 2 months and the parameter assessed was serum gastrin. Increases in serum gastrin were seen in 62.5% (5/8) of rats in group 2 and in 50% (4/8) of rats in group 3. Our results suggest that, in rats, hypergastrinemia is induced by the partial surgical removal of the gastric body and is not due to gastrocystoplasty.

Urinary pH and urea concentration correlate to the bacterial colonization rate in gastric, colonic, ileal and myoperitoneal bladder augmentation

We investigated how various types of augmentation cystoplasty alter the native bacteriostatic properties of urine, particularly urinary urea and pH, in the Sprague-Dawley rat. The augmentation cystoplasties studied included 1 cm.2 and 2 cm.2 patches of colon, ileum and stomach as well as myoperitoneal bladder flaps. Augmentations in order of decreasing incidence of bacteriuria and urinary pH are 2 cm.2 ileal greater than 1 cm.2 ileal greater than 2 cm.2 colonic greater than 1 cm.2 colonic greater than myoperitoneal greater than cystotomy alone greater than 1 cm.2 gastric greater than 2 cm.2 gastric. Urinary urea concentrations were similar between cystotomy alone, and myoperitoneal and gastric augments. In contrast, all colonic and ileal augments had significantly lower urea concentrations compared to the aforementioned groups. Our findings suggest that the type and size of augmentation directly affect urinary pH and urea nitrogen concentration, and the incidence of bacteriuria.

Hypergastrinemia, dysuria-hematuria and metabolic alkalosis: complications associated with gastrocystoplasty

PURPOSE

To help determine the etiology and most appropriate treatment regimen for hypergastrinemia, dysuria-hematuria and metabolic alkalosis following augmentation gastrocystoplasty.

MATERIALS AND METHODS

Two patients who presented with refractory metabolic alkalosis (1 with dysuria-hematuria) underwent extensive laboratory evaluation, complete upper gastrointestinal evaluation and intravesical pH probe placement.

RESULTS

Both patients eventually required high dose oral potassium chloride supplementation. Bladder mucosal pH was not reflected by buffered urinary pH. Both patients demonstrated significant gastroesophageal reflux and diminished overall gastric acid output.

CONCLUSIONS

Outpatient maintenance on potassium chloride supplementation may be warranted in select patients and appears to be preferable to histamine blockade or omeprazole. Postoperative screening esophagogastroscopy and an additional surgical maneuver might be indicated to prevent possible adverse sequelae of reflux esophagitis. Gastrocystoplasty may be an inappropriate operation in children with renal insufficiency who have not had metabolic acidosis.

Gastrocystoplasty: technical and metabolic characteristics of the most versatile childhood bladder augmentation modality

The authors report on 23 patients who underwent complex continent urinary reconstructions, made successful by the selection of gastrocystoplasty as the chosen augmentation modality. The mean patient age was 6.1 years, and the mean weight was 17.9 kg. The minimum follow-up period was 1.5 years. The bladder capacity increased from a preoperative mean of 77.8 +/- 52.2 (SD) mL to a postoperative mean of 303.5 +/- 117.4 mL (P < .000001). No adverse effects on renal function or serum electrolyte composition were encountered, and there were no instances of acidosis or alkalosis. Continence was achieved in 91% of patients. In two patients (0.9%), hematuria-dysuria developed; one case was extremely mild. The other occurred only during a period of severe oliguria and resolved after transplantation. Gastrointestinal complications were minimal. Five patients had end-stage renal disease at the time of reconstruction and have since had successful transplantation. Gastrocystoplasty is particularly applicable to the pediatric population because of its unique anatomic and metabolic characteristics, which bestow tremendous versatility.

Gastropyeloplasty: an alternative procedure in reconstruction of the renal pelvis

We report our first experience with the use of a small gastric patch for reconstruction of the renal pelvis. We performed left gastropyeloplasty based on the right gastroepiploic artery in 1 patient suffering from recurrent urinary tract infections and renal stones, and moderate renal failure. The use of a gastric patch for reconstruction of the renal pelvis prevented the recurrence of calculi and bacterial infections, and produced an improvement in renal function. We confirm the feasibility of the use of a small gastric patch in reconstruction of the renal pelvis and we argue that there are several possible ways to use stomach in upper urinary tract reconstruction.

Autoaugmentation gastrocystoplasty: early clinical results

OBJECTIVE

To assess the urodynamic and clinical outcome of five patients following an autoaugmentation gastrocystoplasty.

PATIENTS AND METHODS

Four patients, two boys and two girls aged between 8 and 16 years, with a neuropathic bladder and incontinence, and one boy, aged 16 years, with an ileal conduit were included in the study. The bladder augmentation technique combined autoaugmentation and the addition of a demucosalized patch of gastric muscle to the created bladder diverticulum.

RESULTS

All patients have improved bladder function, although one may require further surgery. Three had temporary difficulty tolerating full meals.

CONCLUSIONS

This new technique seems to have a place in the management of the neuropathic bladder, but further laboratory study and cautious clinical application is required to ascertain its role in bladder augmentation.

Urinary solute transport by gastric mucosa: a comparison with ileum using a rat model

OBJECTIVES

This study was conducted to quantitate and compare urinary solute transport by stomach and ileum using an in vivo rat model.

METHODS

An artificial urine solution was perfused through isolated gastric and ileal segments in the anesthetized rat. Concentrations of solutes and a volume marker were periodically determined in the perfusate and net solute flux was calculated.

RESULTS

The stomach secretes less sodium and very little bicarbonate in comparison with ileum. Hydrogen ion and chloride are absorbed by ileum but secreted in large quantities by the stomach. Ammonium, potassium, and urea are absorbed by both segments but to a much lesser degree in the stomach. Overall, there was a net osmolar absorption by ileum, and a net secretion by the stomach. Both segments secrete water to a similar degree.

CONCLUSIONS

These findings both suggest the mechanism of the hypochloremic metabolic alkalosis seen after urinary reconstruction with the stomach and provide insight into potential therapeutic approaches. Solute fluxes in both the stomach and the ileum are consistent with the known physiology of these segments.

Bladder peptic ulcer after gastrocystoplasty for radiation cystitis

We report on a woman who underwent gastrocystoplasty for radiation cystitis and in whom a peptic ulcer developed in the native portion of an augmented bladder despite hydrogen blockade medication. The ulcer resolved after the administration of a hydrogen secretion inhibitor. Peptic ulcer may be a potential hazard to patients who undergo gastrocystoplasty after pelvic radiation therapy.

The syndrome of dysuria and hematuria in pediatric urinary reconstruction with stomach

Between July 1989 and March 1992 at a single institution 27 male and 30 female patients underwent lower urinary reconstruction with stomach. Mean patient age was 9.9 years (range 1.5 to 28 years). The diagnoses were epispadias/exstrophy complex (19 patients), myelodysplasia (11), cloacal exstrophy (6), posterior urethral valves (6), Hinman syndrome (4), sacral agenesis (3) and other (8). Indications for surgery were urinary incontinence, upper tract deterioration or undiversion. A total of 54 patients underwent augmentation gastrocystoplasty and 3 had total bladder replacement. Mean followup time was 23.2 months (range 12 to 39 months). The syndrome of dysuria and hematuria is defined as 1 or a combination of the following symptoms: bladder spasm or suprapubic, penile or periurethral pain, coffee brown or bright red hematuria without infections, skin irritation or excoriation and dysuria without infections. Telephone and clinic interviews identified 21 patients (36%) with symptoms of the dysuria and hematuria syndrome. The most common symptoms were hematuria (71%) and bladder or suprapubic pain (76%). Of the patients 18 (86%) ranked the severity of symptoms as mild to moderate and 3 (14%) ranked them as severe. No medications were required to control the symptoms in 13 patients (62%) and 3 other patients only required medications on an as needed basis. Overall patients who required no medications had lower symptom scores than those who required medications. Patients with decreased renal function may be more at risk for the dysuria and hematuria syndrome than those with normal renal function. Patients who were wet were more prone to have the dysuria and hematuria syndrome than those who were totally dry. The pathophysiology of the dysuria and hematuria syndrome is currently unknown. Patients who require urinary reconstruction with stomach tissue need to be made aware of the potential of the dysuria and hematuria syndrome.

Metabolic complications of the use of stomach for urinary reconstruction

A total of 34 children with normal renal function underwent either gastrocystoplasty or continent urinary reservoirs with stomach at our institutions. Severe hypochloremic hypokalemic metabolic alkalosis developed in 2 patients, manifested by intractable seizure disorder in 1 and altered mental status with respiratory depression in 1. Symptoms developed at 4 and 6 months, respectively. Despite severe alkalosis, urinary pH was less than 5.0 and fractional excretion of chloride remained high in both patients. Resuscitation with sodium chloride, arginine hydrochloride and potassium chloride restored electrolyte balance in less than 48 hours in both patients. Serum gastrin was slightly elevated in 1 patient (137 pg./ml., normal 0 to 125) who responded to long-term histamine-blocker therapy. The other patient had significant hypergastrinemia (624 pg./ml.) with secondary hyperaldosteronism. Maximum doses of histamine blockers, oral replacement of sodium chloride and potassium chloride, and the proton pump inhibitor omeprazole failed to control recurrent bouts of severe hypochloremic metabolic alkalosis. This patient ultimately underwent removal of three-quarters of the gastric augmentation and replacement with ileum. Postoperatively, serum gastrin levels and electrolytes reverted to normal. The pathophysiology of this potentially lethal complication is further discussed.

The use of stomach in pediatric urinary reconstruction

We report on 30 consecutive patients (mean age 9 years) who underwent gastrocystoplasty (21) or received a continent urinary reservoir with stomach (9). A successful outcome, defined as complete urinary continence for intervals greater than 3 hours, preservation or improvement of the upper tracts and renal function, and normal electrolyte and acid base balance, was achieved in 90% of the patients who received continent urinary reservoir and 72% of those who underwent gastrocystoplasty. Urodynamic data were obtained in 17 patients in the gastrocystoplasty group and 7 in the continent urinary reservoir group at a mean of 6 months postoperatively. Metabolic alkalosis associated with hypergastrinemia occurred in 2 children. Partial excision of the gastric segment was necessary in 1 patient refractory to medical treatment.

Long-term results of antral gastrocystoplasty

Long-term results of gastrocystoplasty had not been reported in the literature. The results of 10 patients (7 augmentation and 3 replacement) during 15 years were reviewed. All patients voided spontaneously and achieved daytime continence. Enuresis occurred in 3 patients. Median peak flow rate and post-void residual urine were 16.0 ml. per second and 10 ml., respectively. Average cystometric capacity was 554 ml. and median pressure at full capacity was 46 cm. water. Phasic contractions resulted in pressures higher than 50 cm. water in 4 patients. Small capacity, absence of bladder sensation and high pressure were identified as risk factors for a poor result. Routine urine culture was positive in 20.5%. Urine mucus content remained low. Electrolyte disturbance, histopathological abnormalities and ulcer syndrome related to hypergastrinemia were absent. The data showed that antral gastrocystoplasty is superior because of the low infective complication rate, ability to empty and absence of metabolic disturbance.