Nutritional and Gastrointestinal Complications of the Use of Bowel Segments in the Lower Urinary Tract

Multidisciplinary management of people with spina bifida across the lifespan

The average worldwide prevalence of neural tube defects (NTDs) is 1.0 per 1000 births. Its development is multifactorial due to genetic and non-genetic factors. Spina bifida (SB) is one of main representatives of NTD. The spinal cord lesion level is the main determinant of the level of paralysis, numbness, and difficulties with bladder/bowel functions. Myelomeningocele prenatal repair reduces hydrocephalus and hindbrain herniation and improves motor function. The severity of hydrocephalus is associated with poorer neurodevelopmental outcomes whether operated on prenatally or after birth. People with SB tend to have a lower IQ and cognitive difficulties. Early diagnosis, proactivity, and lifelong multidisciplinary follow-up are key protective issues. Invasive urological interventions should be considered in selected patients after failure of conservative treatment. Transition to adult care should be well planned as it is challenging. Health literacy is directly associated with success at transition. Sexuality and fertility should be addressed before/during puberty. Overall, the rates of fecal and urinary continence and skin breakdown increase with age, whereas the ability to ambulate declines with age. Bowel and urinary incontinence are independent predictors of lower health-related quality of life (HRQoL) in adults with SB. Bowel incontinence has negative impact on HRQoL regardless of frequency or amount. Long-term caregiver support should be offered at diagnosis. Survival at a mean of 50 years is poor, at 32%, due to central nervous system deaths, cancer, urological disease, and sepsis. Challenges to implementation of recommended practices exist, especially in low and middle-income countries.

Female pelvic organ-preserving robot-assisted simple cystectomy and intracorporeal ileal neobladder reconstruction on a young woman with Hunner-type interstitial cystitis

Introduction

Cystectomy is the last treatment option for Hunner-type interstitial cystitis. However, consensus regarding optimal patient selection or treatment approaches is lacking.

Case presentation

A 27-year-old woman presented to a regional hospital with bladder pain and frequent urination. Antimicrobial therapy was administered; however, her symptoms persisted and she was finally diagnosed with HIC. Multiple endoscopic fulgurations of Hunner's lesions with bladder hydrodistension or intravesical therapy were performed; however, the symptoms persisted. A urethral catheter was inserted 1 month before she visited our clinic because of a severely contracted bladder. We performed female pelvic organ-preserving robot-assisted simple cystectomy and intracorporeal ileal neobladder reconstruction. The patient's postoperative course was uneventful and her symptoms resolved.

Conclusion

This is the first report of pelvic organ-preserving robot-assisted simple cystectomy and intracorporeal ileal neobladder reconstruction in a young woman with HIC.

Functional, Diagnostic and Therapeutic Aspects of Bile

Bile is a unique body fluid synthesized in our liver. Enterohepatic circulation preserves bile in our body through its efficient synthesis, transport, absorption, and reuptake. Bile is the main excretory route for bile salts, bilirubin, and potentially harmful exogenous lipophilic substances. The primary way of eliminating cholesterol is bile. Although bile has many organic and inorganic contents, bile acid is the most physiologically active component. Bile acids have a multitude of critical physiologic functions in our body. These include emulsification of dietary fat, absorption of fat and fat-soluble vitamins, maintaining glucose, lipid, and energy homeostasis, sustenance of intestinal epithelial integrity and epithelial cell proliferation, reducing inflammation in the intestine, and prevention of enteric infection due to its antimicrobial properties. But bile acids can be harmful in certain altered conditions like cholecystectomy, terminal ileal disease or resection, cholestasis, duodenogastric bile reflux, duodenogastroesophageal bile reflux, and bile acid diarrhea. Bile acids can have malignant potentials as well. There are also important diagnostic and therapeutic roles of bile acid and bile acid modulation.

Evaluation of Bowel Function Following Radical Cystectomy and Urinary Diversion Using Two Validated Questionnaires: What Are the Effects on Quality of Life?

OBJECTIVE

To assess both short- and long-term constipation symptoms and their impact on quality of life in patients who underwent radical cystectomy (RC) with three different types of urinary diversion: orthotopic neobladder (ONB), continent cutaneous diversion (CCD), and ileal conduit (IC).

MATERIALS AND METHODS

The validated Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires were administered to all patients at follow-up greater than 30 days from surgery. Clinical and pathological characteristics were prospectively recorded in an institutional review board approved bladder cancer database. Using multivariable linear regression analyses, we determined significant predictors of improved constipation symptoms and quality of life scores.

RESULTS

A total of 198 patients completed 255 PAC-SYM and PAC-QOL questionnaires with a median follow-up time of 1.7 years (IQR: 0.7 - 3.0 years). ONB, CCD, and IC were performed in 78%, 5.5%, and 16.5% of patients, respectively. Higher bowel function scores (i.e. worse symptoms) were noted at 3 months post-operatively, while these scores significantly improved over time for PAC-SYM total score (P = .004), abdominal subscore (P = .001), and rectal subscore (P = .018). On multivariable analysis, we found that patients <70 years old (B -2.1, P = .004), with follow-up >1 year (B -4.8, P = .001), and who received an IC (B -2.4, P = .02) had significantly lower PAC-SYM scores.

CONCLUSION

Patients have few constipation symptoms and are overall satisfied with their bowel function at long-term follow-up after RC. While patients with IC have significantly fewer constipation symptoms compared to those with ONB or CCD, all patients had significant improvement one year after the surgery.

Bowel Resection and Ileotransverse Anastomosis as Preferred Therapy for 15 Typhoid Ileal Perforations and Severe Peritoneal Contamination in a Very Elderly Patient

Typhoid ileal perforation (TIP) is the most lethal complication of typhoid fever. Although TIP is a surgical emergency by consensus, there is still much controversy regarding the most appropriate surgical approach to be used. Bowel exteriorization and secondary closure are usually recommended for patients presenting late with multiple TIPs and heavy peritoneal soiling. We, however, discuss a unique case of an 86-year-old patient with 15 typhoid ileal perforations successfully treated with one-step surgery comprising bowel resection and ileotransverse anastomosis in a resource-constrained setting of Cameroon.

Metabolic and Nutritional Consequences of Urinary Diversion Using Intestinal Segments to Reconstruct the Urinary Tract

Intestinal segments in various forms have been used to reconstruct the urinary tract since the mid-1800s. Currently, many different forms of continent and incontinent diversion options exist. Incorporating bowel mucosa within the urinary tract leads to predictable metabolic and nutritional consequences. The use of ileum or colon can cause a hyperchloremic metabolic acidosis, vitamin B12 deficiency, osteoporosis, fat malabsorption, urinary calculi, and ammoniagenic encephalopathy. Due to metabolic and nutritional consequences associated with the use of jejunum and gastric segments, the use of these bowel segments is not recommended.

Bowel function in patients with urinary diversion: a gender-matched comparison of continent urinary diversion with the ileocecal pouch and ileal conduit

PURPOSE

To evaluate stool habits and associated quality of life (QoL) in a matched pair analysis of patients who underwent continent cutaneous diversion using the ileocecal segment [Mainz pouch I (MzPI)] with an intussuscepted ileal nipple as efferent segment with those receiving an ileal conduit (IC) after radical cystectomy.

METHODS

We identified 250 patients who underwent radical cystectomy and urinary diversion (UD) with either MzPI with an ileal nipple or IC in our database. A detailed history of stool habits using the modified Wexner score was obtained, and questions addressing general lifestyle, comparison of symptom differences before and after surgery considering bowel function as well as bowel-associated QoL were assessed.

RESULTS

Forty-five age- and sex-matched pairs could be compared. Overall, stool incontinence (p = 0.481) and the Wexner score (p = 0.464) revealed no differences between both groups. However, patients with MzPI as compared to those with IC had significant higher rates of stool frequency (53 vs 31 %), softer stool consistencies (60 vs 13 %), diarrhea (62 vs 20 %) and a lower rate of constipation (4 vs 22 %). Patients with MzPI had a trend toward lower bowel-associated QoL compared with patients with IC. Similarly, the MzPI group reported a significantly impaired overall postoperative QoL (51 %) compared to the IC group (29 %) (p = 0.024).

CONCLUSIONS

Patients following UD by MzPI have an increased stool frequency and softer stool consistency. However, there is no difference between both groups in terms of de novo stool incontinence. Change in bowel habits should be part of preoperative informed consent in any kind of UD. Careful patient selection is of paramount importance.

Metabolic consequences after urinary diversion

Metabolic disturbances are well-known, but sometimes neglected immediate consequences or late sequelae following urinary diversion (UD) using bowel segments. Whereas subclinical disturbances appear to be quite common, clinically relevant metabolic complications, however, are rare. Exclusion of bowel segments for UD results in loss of absorptive surface for its physiological function. Previous studies demonstrated that at least some of the absorptive and secreting properties of the bowel are preserved when exposed to urine. For each bowel segment typical consequences and complications have been reported. The use of ileal and/or colonic segments may result in hyperchloremic metabolic acidosis, which can be prevented if prophylactic treatment with alkali supplementation is started early. The resection of ileal segments may be responsible for malabsorption of vitamin B12 and bile acids with subsequent neurological and hematological late sequelae as well as potential worsening of the patient's bowel habits. Hence, careful patient and procedure selection, meticulous long-term follow-up, and prophylactic treatment of subclinical acidosis is of paramount importance in the prevention of true metabolic complications.

Bladder augmentation and urinary diversion in patients with neurogenic bladder: non-surgical considerations

Segments from almost all parts of the bowel have been used for urinary diversion. As a result, the available absorptive surface area of the bowel is reduced, and the incorporation of bowel segments into the urinary tract may have metabolic consequences. This is an area somewhat neglected in the literature. Metabolic complications are rare, but sub-clinical metabolic disturbances are quite common. Several studies have demonstrated that some of the absorbent and secreting properties of the bowel tissue are preserved after incorporation into the urinary tract. Hyperchloraemic metabolic acidosis can occur if ileal and/or colon segments are used, as well as malabsorption of vitamin B(12) and bile acid after the use of ileal segments. These metabolic effects are not as severe as may be suspected and can be prevented by prophylactic substitution. Secondary malignancies can develop as a long-term consequence of bladder augmentation. Using colonic segments, tumours are most likely to occur at the ureteral implantation site. To prevent metabolic complications, careful patient selection and meticulous and lifelong follow up, as well as prophylactic treatment, are mandatory. Endoscopy for early detection has been recommended, starting 10 years postoperatively for patients who underwent surgery for a benign condition.

[Metabolic aspects of bowel use in urologic surgery]

Urinary diversion, pouches and orthotopic bladder replacement have been made possible by the use of bowel segments in urologic surgery. The most important complications at short and long-term are metabolic disorders due to the permanent contact of urine with the bowel segment or the exclusion of this segment from bowel continuity. Metabolic acid-base problems occur immediately after the derivation beginning and depend on the renal capacity to compensating. The metabolic disorder due to the exclusion of a bowel segment appears generally years later, after complete depletion of physiologic reserves (vitamin B12). Perfect knowledge of early and late metabolic complications of urinary diversion allows a more accurate indication, a more adequate selection of the derivation type, an improved patient followup, and better long-term results. Metabolic complications constitute the best selection criteria for urinary diversion; subsequently, only a few techniques are likely to persist in the future.

Urinary conduit formation using retubularized bowel from continent urinary diversion or intestinal augmentations: I. A multi-institutional experience

OBJECTIVES

To present our multi-institutional experience with retubularized bowel conduits. Some patients with augmentation cystoplasty, augmented rectal bladder, or continent urinary reservoirs require conversion to an ileal conduit for various reasons. This is generally accomplished by construction of a de novo ileal conduit. We retubularized the bowel segment used in the augmented bladder or the urinary reservoir to form the intestinal urinary conduit.

METHODS

A total of 29 patients (mean age 42 years) underwent conduit formation using the augmentation patch of enterocystoplasty, the segment of cutaneous urinary diversion reservoir or orthotopic neobladder, or the augmentation patch of an augmented rectal bladder. Patients were followed up with history, physical examination, laboratory tests, and imaging studies.

RESULTS

The follow-up ranged from 12 to 130 months (mean 42). One patient developed small bowel obstruction requiring laparotomy with lysis of adhesions. None of the other patients had bowel complications. Two patients developed ureteral obstruction with hydronephrosis. One had pyocystitis requiring simple cystectomy. One patient was lost to follow-up.

CONCLUSIONS

Retubularization of previously used bowel segments to construct a urinary conduit is feasible and has several advantages. It is possible to perform this procedure after several types of reconstructive procedures in which bowel was incorporated into the urinary tract.

Urolithiasis in enterocystoplasties

The incidence of stones in patients with enterocystoplasty is reported as 12-52.5%. Most patients will have multiple physical factors such as immobility, need for self catheterisation and poor urine drainage, so that it is not certain that an intestinal reservoir is the cause of stones on its own. There is little or no evidence that mucus is an aetiological factor. Foreign bodies in the reservoir, such as staples, increase the risk of stone formation from 13% to 43%. Stones require surgical removal. Minimally invasive techniques may be used for small stones. A low velocity disintegrator is required so that fragments are not propelled into the intestinal mucosa. Stones are infective in origin in 86% of cases, but 14% are sterile. Metabolic screen shows that 80% of patients have risk factors for at least three different types of stone. All patients have raised pH (mean 6.93) and hypocitraturia. Raised serum and urinary calcium, hyperoxaluria and hyperuricosuria are found in up to 33% of patients.

Bowel function after urinary diversion

Removal of bowel segments for the purposes of urinary diversion may have a significant effect on bowel function. The remaining bowel may not be able to fulfill its normal role, resulting in not only malabsorption syndromes, but also dysfunctional defecation. Provided, however, care is taken in selecting patients and the bowel segments for such procedures and follow-up is vigilant, complications should be minimal. There appears to be a significant risk of developing symptoms of increased bowel frequency following urinary diversion and reconstruction. Patients need to be counselled regarding this prior to surgery, however, further data needs to be collected to accurately quantify the risk and the effect it has on quality of life.

Fat malabsorption induced by gastrointestinal lipase inhibitor leads to an increase in urinary oxalate excretion

BACKGROUND

Unabsorbed fat and bile acids may react with calcium in the intestinal lumen, limiting the amount of free calcium binding with oxalate and thereby raising intestinal oxalate absorption leading to hyperoxaluria. The aim of the present study was to determine whether orlistat (Xenical), a gastrointestinal lipase inhibitor, might increase urinary oxalate in an experimental rat model.

METHODS

Thirty-nine male adult Wistar rats were fed a standard diet alone (controls) or supplemented with either 2% sodium oxalate (NaOx) or 3.2 mL of soy oil, or with both (NaOx + soy oil) for 4 weeks (diet period). Orlistat (16 mg/day) was added to the diet from the 5th to the 8th week (diet + orlistat period). Urinary oxalate (uOx), calcium (uCa), magnesium (uMg), and citrate (uCit) were determined and the ion-activity product of calcium oxalate [AP (CaOx) index(rat)] was estimated.

RESULTS

Compared to baseline uOx significantly increased after diet + orlistat in controls (0.64 +/- 0.1 mg/24 hours vs. 0.56 +/-0.1 mg/24 hours), soy oil (0.80 +/- 0.3 mg/24 hours vs. 0.49 +/-0.2 mg/24 hours), and NaOx (2.48 +/- 0.8 mg/24 hours vs. 0.57 +/- 0.2 mg/24 hours), but the most marked increase occurred in NaOx + soy oil (3.87 +/- 0.7 mg/24 hours vs. 0.47 +/- 0.1 mg/24 hours). All groups except controls presented a significant reduction in uCa and uMg. Orlistat induced a significant increase in AP (CaOx) index(rat) compared, respectively, to baseline and to the diet period in NaOx (4.52 +/- 2.34 mg/24 hours vs. 0.94 +/- 0.86 and 1.53 +/- 0.93 mg/24 hours) and NaOx + soy oil (6.49 +/- 4.03 mg/24 hours vs. 0.54 +/- 0.17 and 1.76 +/- 1.32 mg/24 hours).

CONCLUSION

These data suggest that the use of lipase inhibitors, especially under a diet rich in oxalate alone or associated with fat, leads to a significant and marked increase in urinary oxalate and a slight reduction in uCa and uMg that, taken together, resulted in an increase in AP (CaOx) index(rat), elevating the risk of stone formation.

Urothelial ingrowth over demucosalized gastrocystoplasty: an experimental study

OBJECTIVE

To evaluate histopathologically the ingrowth of urothelium over a demucosalized gastric flap used for augmentation, as such flaps increase the capacity of the bladder if the urothelium can cover the seromuscular patch.

MATERIALS AND METHODS

The study included eight male dogs; the urinary bladder was widely divided at its dome anteroposteriorly to receive a seromuscular gastric flap, sutured to the edges of the urinary bladder. Before and 1 month after surgery the changes in bladder capacity and pressure were recorded, and urothelial ingrowth assessed histopathologically.

RESULTS

Two of the eight dogs died; the increase in mean bladder capacity in the remaining dogs was 20% and the decrease in mean intravesical pressure 34%. Gross pathological examination of the urinary bladder showed good 'take' of the gastric flap by the urinary bladder. Histopathologically, there was good healing of the flap, active ingrowth of urothelium, and no mucosal re-growth.

CONCLUSION

Bladder augmentation with a demucosalized gastrocystoplasty allows the creation of a large compliant urinary bladder with few complications caused by the incorporation of the enteric or gastric epithelium into the urinary bladder. The stomach has a rich blood supply, allowing the harvesting of a well-vascularized flap, and urothelial ingrowth over this flap in the present study was significant.

Vitamin B12 malabsorption following bladder reconstruction or diversion with bowel segments

BACKGROUND

Vitamin B12 is absorbed exclusively in the terminal ileum the resection of which may produce malabsorption of B12. The present study aimed to determine whether the length or specific segment of the intestine used in bladder reconstruction affects the overall incidence of B12 malabsorption. It was also aimed at the reasonable way of following these patients.

METHODS

Seventy patients who underwent urinary reconstruction between 1988 and 1997 were studied: 28 had undergone orthotopic reconstruction, 14 had ileal conduit diversion, 8 had continent diversion and 20 had undergone enterocystoplasty. The median follow up was 65 months (10-137 months). Indications for operation included carcinoma of the bladder, neurogenic bladder dysfunction, idiopathic detrusor instability and interstitial cystitis. Schilling tests were performed, and serum B12 level and haematological indices were measured.

RESULTS

Patients were classified depending on whether the ileocaecal junction was used. Group 1 included ileal conduit and entero-cystoplasty where 15-20 cm of ileum, 15-20 cm from ileocaecal junction was used. Group 2 consisted of orthotopic reconstruction and continent diversions where the ileocaecal segment was used. Group 3 comprised patients in whom long ileal segments (50-60 cm) had been used for reconstruction. Five patients in group 1 and one in group 2 had low B12 levels, but none had developed neuropathy or megaloblastic anaemia. One patient in group 1, and six patients in group 2 had low Schilling tests indicating intestinal malabsorption of B12. No patient in group 3 had a low B12 or an abnormal Schilling test.

CONCLUSION

This study showed that use of ileocaecal segments results in intestinal malabsorption of B12. The length of ileum alone does not seem to be the determinant factor in causing B12 deficiency or B12 malabsorption.

Vitamin B12 metabolism after urinary diversion with a Kock ileal reservoir

OBJECTIVE

To elucidate the influence of construction of a Kock reservoir for urinary diversion using 70 cm of the distal ileum on vitamin B12 metabolism.

MATERIAL AND METHODS

Blood samples for determination of cobalamin concentrations were drawn up to 18 years after construction of a Kock reservoir in 97 patients. Preoperative values were obtained in 20 of these patients. Pre- and postoperative Schilling tests and analyses of methylmalonic acid and homocysteine concentrations were performed in subgroups.

RESULTS

The operation did not induce a significant decrease in cobalamin uptake as reflected in the pre- and postoperatively performed Schilling tests. No significant decline in cobalamin concentration postoperatively was noted. The value of analysis of methylmalonic acid and homocysteine concentrations in finding patients with cobalamin deficiency is limited by the fact that kidney function influences the results. Ten per cent of the patients did develop true cobalamin deficiency. A postoperative vitamin B12 value below 200 pmol/l indicates a 50% risk of later cobalamin deficiency.

CONCLUSIONS

The construction of a Kock reservoir does not per se cause cobalamin deficiency. Substitution should be instituted at a postoperative concentration below 200 pmol/l.

Decreased linear growth associated with intestinal bladder augmentation in children with bladder exstrophy

PURPOSE

We determine if enterocystoplasty results in delayed linear growth using a case controlled study to observe the effects of intestinal bladder augmentation on growth in patients with bladder exstrophy.

MATERIALS AND METHODS

A total of 50 patients who had undergone bladder augmentation for incontinence due to classic bladder exstrophy were selected from our patient database and matched for gender, age and type of exstrophy with 50 patients who had nonaugmented bladder exstrophy. Patients were then contacted and asked to permit the pediatricians to release growth charts. Once consent was obtained the charts were requested from the pediatricians, and evaluable data, defined as at least 1 height before and after augmentation, were obtained for 17 of 50 (34%) augmented and 15 of 50 (30%) nonaugmented cases.

RESULTS

Mean age at surgery was 7.7 years. Delayed growth as defined by a postoperative decrease in percentile height occurred in 14 of 17 (82%) augmented cases (mean loss 15.6 percentile points). Delayed growth after age 7.7 years occurred in 5 of 15 (33%) controls but average growth for the entire group was 6.7 percentile points (p = 0. 014). Mean followup was 5.7 years (median 4.9) for the augmented group and 7.3 years (median 8.2) for the control group.

CONCLUSIONS

Intestinal bladder augmentation is associated with a nearly universal decrease in percentile height. Close long-term followup of these patients and analysis of subtle metabolic alterations may provide information to help minimize or prevent growth impediment in the future.

The relationship between Helicobacter pylori infection and acid-hematuria syndrome in pediatric patients with gastric augmentation-II

BACKGROUND/PURPOSE

The acid-hematuria syndrome, which presents with dysuria, hematuria, and perineal pain still remains a problem in those patients who have undergone bladder augmentation using the gastrocystoplasty technique. Additionally, there is still a question regarding the explanation for postoperative metabolic problems such as metabolic alkalosis, hypocholoremia, hypergastrinemia, and various complications related to gastritis and peptic ulcer disease. The aim of this study was to investigate the relation of Helicobacter pylori (HP) infection in this patient group and the relationship between HP infection and the above-mentioned clinical problems and complications.

METHODS

In this study, 10 children with a history of previous gastrocystoplasty (five girls, five boys; mean age, 6.75+/-2.53 years; range, 2.5 to 12 years) were evaluated. Blood samples for HP detection were analyzed by serological testing (ELISA technique). Histopathologic studies were performed for gastric tissue specimens, obtained by endoscopic procedures from the stomach and augmented bladder. Urine pH and serum gastrin levels were measured in all patients.

RESULTS

Regarding the serological studies, four of ten patients had a positive ELISA test result (40%). The four patients with HP-positive serological test results, were the patients who had acid-hematuria syndrome. These patients also had low urine pH levels (mean, 4.5) when compared with those of HP-negative patients. HP-positive patients also had high serum gastrin levels in comparison with those of HP-negative patients.

CONCLUSIONS

The relation between HP infection and problems such as hypergastrinemia, acid output, and ulcer disease is well known. Our study demonstrates a correlation between the HP-positive gastrocystoplasty patients and the above-mentioned symptoms and complications. Because of the potential risk of HP infection, we suggest that HP infection be investigated in patients with gastrocystoplasty or in candidates for a gastrocystoplasty operation. HP-positive patients should be treated, to reduce the risks of postoperative complications.

Bowel motility after enterocystoplasty

OBJECTIVE

To determine whether the distension of bowel-augmented bladders during filling and urine storage stimulates gastrointestinal peristalsis, resulting in diarrhoea and increased bowel frequency.

PATIENTS AND METHODS

Five patients with symptomatic diarrhoea occurring after enterocystoplasty were studied; all had undergone bladder augmentation using ileum or colon at least 6 months previously. Using bowel frequency charts and colonic transit-time studies, their bowel function was assessed over 6 days while patients self-catheterized 4-hourly. This was repeated when the patient's bladders were decompressed with an indwelling catheter, and the results before and after bladder decompression compared.

RESULTS

One patient showed a significant increase in colonic transit time, from 44.4 to 57.6 h, a decrease in the percentage of liquid motions from 50% to 42.8% and a corresponding small decrease in bowel frequency with bladder decompression. One patient reported an increase in liquid stools, but there was a minor decrease in colonic transit time. The remaining three patients showed no improvement with bladder decompression. When data were combined and analysed using Student's paired t-test, there were no significant changes in colonic transit time, bowel frequency and diarrhoea stools with bladder decompression.

CONCLUSIONS

Eliminating bladder distension and hence distension of the incorporated bowel segment in reconstructed bladders has no impact on bowel motility.

Long-term nutritional consequences of bowel segment use for lower urinary tract reconstruction in pediatric patients

OBJECTIVES

To identify whether nutritional abnormalities, specifically vitamin B12 deficiency, folate deficiency, and low carotene levels, are long-term sequelae of the use of ileum and/or colon for lower urinary tract reconstruction in pediatric patients.

METHODS

Serum levels of vitamin B12, methyl malonic acid (MMA), carotene, and folate were measured 3 to 13 years (mean 6) after surgery in patients less than 18 years old at the time of operation.

RESULTS

Thirteen (44.8%) of 29 patients had abnormal nutritional serum levels, with 5 (38.5%) of 13 having more than one abnormal value. Vitamin B12 was low in 4 (14%) of 29 patients; MMA was abnormally high in 7 (26%) of 27; and both folate and carotene levels were low in 4 (14.8%) of 27. No patient with reconstruction with colon alone (n = 3) had abnormal values, and no patient had any clinical signs or symptoms of vitamin B12 deficiency or fat malabsorption.

CONCLUSIONS

Nutritional abnormalities can occur in patients after lower urinary tract reconstruction with ileum. No patient in this study had symptomatic abnormalities; however, long-term clinical effects may be significant. The implications of low folate levels in women of childbearing age must also be taken into consideration because of the potential association with congenital anomalies.

The use of in bowel urology. Metabolic and nutritional complications

Metabolic and nutritional complications of urinary diversion through bowel or stomach segments are common, but fortunately, not often severe. When metabolic abnormalities are problematic, deterioration or baseline insufficiency in renal function is the most likely cause. Deterioration is most commonly associated with obstruction or infection. The urologist should be acutely aware of the potential for metabolic derangements when the prediversion creatinine is greater than 2.0 mg/dL. In this situation, the urologist should employ the basic principles in this article when planning the procedure in order to minimize metabolic complications and morbidities. In the setting of significant renal insufficiency, a short colon or ileal conduit would likely be superior to an ileal or colonic neobladder, or a diversion, incorporating a large gastric segment. Furthermore, in the absence of symptomatic metabolic abnormalities, we advocate treatment of minor laboratory abnormalities, particularly acidosis, to reduce the incidence of metabolic bone disease. Nutritional and gastrointestinal complications are treated on an "as needed" basis, with the exception of metabolic bone disease, which we would hope to prevent with alkalinization and Vitamin C supplementation. Some of the nutritional and gastrointestinal complications are best avoided by leaving the ileocecal valve intact, or by minimizing the use of certain segments. Some evidence exists that over time, histologic changes in the epithelium of diversion segments may impair absorption and contribute to greater resistance against metabolic derangements. Whether the changes truly reduce the incidence of metabolic abnormalities remains to be studied. The ideal, complication-free, diversion with universal application does not exist; however, the urologist must strive to select an option that will provide a functional result for the patient with minimal associated morbidity.

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.

Vitamin B12 deficiency in patients with urinary intestinal diversion

BACKGROUND

Because vitamin B12 is absorbed exclusively by the terminal ileum, we investigated vitamin B12 deficiency as a potential metabolic complication after urinary intestinal diversion.

METHODS

We measured serum levels in patients with Kock pouches (n = 35); Indiana pouches (n = 27); and ileal conduits (n = 25). Serial determinations of serum B12 levels were obtained in 19 patients with kock pouches and 14 patients with Indiana pouches. The dual-isotope Schilling test was performed in 9 patients with Kock pouches and 6 patients with Indiana pouches.

RESULTS

No patient had an abnormally low serum B12 level (< 200 pg/mL). Mean (+/-SD) serum B12 levels in patients with the Kock pouch (506 +/- 202 pg/mL) and the Indiana pouch (536 +/- 249 pg/mL) were lower than that in patients with the ileal conduit (727 +/- 391 pg/mL). The mean serum B12 level was not significantly different between patients with and without preoperative irradiation. Serial determinations showed that serum B12 levels in some patients with continent urinary reservoirs were persistently near the lower normal limit, or became progressively lower. Three of the 9 patients (33%) with Kock pouches and 4 of the 6 patients (67%) with Indiana pouches were B12 malabsorbers, although no patients had megaloblastic anemia or neurologic symptoms.

CONCLUSIONS

Some patients with continent urinary reservoirs are at risk for vitamin B12 deficiency due to malabsorption. Routine evaluation of serum B12 levels is recommended for all patients with continent urinary reservoirs, and a Schilling test for those with subnormal serum B12 levels.

Bladder Replacement and Urinary Diversion After Radical Cystectomy

BACKGROUND: The optimal mode of urinary tract reconstruction following cystectomy continues to challenge the urologic surgeon. Disadvantages with bowel conduits have prompted the search for better techniques to improve patient outcomes. METHODS: The development of urinary tract reconstruction is reviewed, and results from several forms of continent urinary diversion and bladder replacement construction are presented. The authors report on their experience in creating continent reservoirs or neobladders in over 400 patients. RESULTS: Several surgical approaches are now available for continent urinary diversion. Metabolic and nutritional abnormalities, stone formation, infection, and cancer formation are potential complications. CONCLUSIONS: Advances in surgical techniques, an understanding of the physiology of isolated bowel segments, and improvements in pre- and post-operative care have altered the field of urinary reconstruction after cystectomy for bladder cancer. Most patients can expect minimal morbidity and mortality.

Effect of urinary intestinal diversion on urinary risk factors for urolithiasis

We investigated the effect of urinary intestinal diversion on risk factors for calcium urolithiasis, such as calcium, phosphate, magnesium, uric acid, oxalate and citrate, in 3 groups of patients (Kock pouch, Indiana pouch and ileal conduit). Mean urinary volume was not significantly different among the 3 groups. Mean serum creatinine and 24-hour creatinine clearance in the continent reservoir group were better than in the ileal conduit group. Mean urinary excretion of calcium, phosphate and magnesium was significantly greater in the continent reservoir group than in the ileal conduit group. Although calcium excretion had a positive correlation with 24-hour creatinine clearance, calcium excretion per ml. per minute creatinine clearance still showed a significant difference. Increased calcium excretion is considered to reflect metabolic disturbances resulting from reabsorption of urinary solutes through the intestinal segments. Overall, there was no significant difference in the urinary parameters between the Kock and Indiana pouch groups. While mean urinary oxalate and citrate were within the normal range in all 3 groups, more than a third of the patients in each group were hypocitraturic (less than 100 mg. per day). In none of the 3 groups did the levels of urinary calcium, phosphate and magnesium, as well as other urinary risk parameters show any correlation with the duration of diversion. In summary, our study indicated that the continent urinary reservoir causes a long-term increase in urinary excretion of calcium, phosphate and magnesium. These urinary metabolic alterations might promote the formation of calcium urolithiasis as well as infectious stones. The degree of metabolic alterations may be greater with a continent reservoir than with an ileal conduit.

Continent urinary reservoirs

With the increasing incidence of bladder cancer, many different operations have been devised to reconstruct the lower urinary tract in a continent fashion. The incontinent type of urinary reservoir (ileal conduit) has been a surgical preference for many years. However, the continent urinary reservoir (CUR), neobladder, and rectal bladder offer the capable and motivated patient an alternative to an incontinent permanent stoma. Nursing management of patients requiring diversional surgery requires continual updating of these specialized surgical procedures and unique aspects of care.

Urolithiasis in children following augmentation cystoplasty

Until recently urolithiasis in children following augmentation cystoplasty was an infrequently noted problem. We examined our 10-year experience and found urinary calculi to form in 52% of children and young adults undergoing augmentation cystoplasty. Calculi formed at a median interval of 24.5 months after surgery, predominantly in the lower tract. Urinary tract infection was a statistically significant risk factor, while the use of absorbable staples, intestinal mucus and hypocitraturia were also implicated. Calculus composition was primarily a mixture of apatite, struvite and ammonium urate. Bladder calculi were effectively managed endoscopically in the majority of cases without complication. Upper tract calculi presented an endourological challenge.