Long-term metabolic effects of urinary diversion: a comparison of myelomeningocele patients managed by clean intermittent catheterization and urinary diversion

Secondary Osteoporosis

Osteoporosis is a global public health problem, with fractures contributing to significant morbidity and mortality. Although postmenopausal osteoporosis is most common, up to 30% of postmenopausal women, > 50% of premenopausal women, and between 50% and 80% of men have secondary osteoporosis. Exclusion of secondary causes is important, as treatment of such patients often commences by treating the underlying condition. These are varied but often neglected, ranging from endocrine to chronic inflammatory and genetic conditions. General screening is recommended for all patients with osteoporosis, with advanced investigations reserved for premenopausal women and men aged < 50 years, for older patients in whom classical risk factors for osteoporosis are absent, and for all patients with the lowest bone mass (Z-score ≤ -2). The response of secondary osteoporosis to conventional anti-osteoporosis therapy may be inadequate if the underlying condition is unrecognized and untreated. Bone densitometry, using dual-energy x-ray absorptiometry, may underestimate fracture risk in some chronic diseases, including glucocorticoid-induced osteoporosis, type 2 diabetes, and obesity, and may overestimate fracture risk in others (eg, Turner syndrome). FRAX and trabecular bone score may provide additional information regarding fracture risk in secondary osteoporosis, but their use is limited to adults aged ≥ 40 years and ≥ 50 years, respectively. In addition, FRAX requires adjustment in some chronic conditions, such as glucocorticoid use, type 2 diabetes, and HIV. In most conditions, evidence for antiresorptive or anabolic therapy is limited to increases in bone mass. Current osteoporosis management guidelines also neglect secondary osteoporosis and these existing evidence gaps are discussed.

Update on bone fragility in spina bifida

BACKGROUND CONTEXT

Patients with spina bifida (SB) are at risk for pathological fractures and low bone mineral density (BMD).

PURPOSE AND METHODS

This article reviews the literature and provides a comprehensive overview of how the characteristics of SB and its associated comorbidities intersect with bone fragility to identify possible pathophysiological mechanisms of fractures and low BMD.

RESULTS

Bone fragility occurs early in the life of patients with SB as a result of a disturbance that determines changes in bone shape, quantity, and quality, as poor mineralization reduces bone stiffness. Bone fragility in SB occurs due to local and systemic factors and may be considered a state of impaired bone quality of multifactorial aetiology, with complex interacting influences of neurological, metabolic, and endocrinological origins and the presence of smaller bones. Bone fragility should be evaluated globally according to skeletal age and Tanner staging. The phases of the evolution of Charcot joints seem to intercept the evolution of epiphyseal fractures. Charcot arthropathy in SB may be initiated by the occurrence of repetitive trauma and fractures in epiphyseal and subepiphyseal regions, where there is a deficit of bone mineralization and greater bone mass deficits.

CONCLUSION

Bone fragility in MMC potentially has a multifactorial neuro-endocrinological-metabolic-renal dimension, with smaller bones, lower bone mass, and mineralization deficits affecting bone strength.

Fractures in spina bifida from childhood to young adulthood

This study assessed the prevalence and types of fractures in spina bifida and examined risk factors for fracture. Fracture prevalence was highest in childhood and reduced in adolescence and young adulthood. The importance of maintaining mobility is highlighted by the increased risk of fracture in those who are non-ambulatory.

INTRODUCTION

The aims of this study are to study the prevalence and types of fractures according to age group in spina bifida and examine risk factors associated with fracture.

METHODS

This is a retrospective cohort study of 146 individuals with spina bifida aged 2 years or older who attended the paediatric or adult spina bifida multidisciplinary clinic at a single tertiary hospital.

RESULTS

Median age at which first fracture occurred was 7 years (interquartile range 4-13 years). Fracture rates in children (ages 2-10), adolescents (ages 11-18) and adults (age > 18) were 10.9/1000 (95 % confidence interval 5.9-18.3), 5.4/1000 (95 % CI 1.5-13.8) and 2.9/1000 (95 % CI 0.6-8.1) patient years respectively. Childhood fractures predominantly involved the distal femur and femoral shaft; these fractures were rarely seen in adulthood. Non-ambulatory status was associated with a 9.8 times higher risk of fracture compared with ambulatory patients (odds ratio 9.8, p = 0.016, 95 % CI 1.5-63.0). Relative risk of re-fracture was 3.1 (95 % CI 1.4-6.8). Urological intervention with intestinal segments was associated with renal calculi (p = 0.037) but neither was associated with fracture.

CONCLUSIONS

The risk of fracture is lower in adults compared with children with spina bifida. The predominant childhood fracture affects the distal femur, and immobility is the most significant risk factor for fracture. Clinical factors contributing to fracture risk need to be elucidated to enable selection of patients who require investigation and treatment of osteoporosis.

Enterocystoplasty: The long-term effects on bone mineral density

BACKGROUND

Studies show that enterocystoplasty has a negative effect on bone mineral density (BMD). The aim of this study was to investigate the long-term impact of enterocystoplasty on BMD. We used dual energy x-ray absorptiometry (DEXA) scans to determine BMD and identify patients with osteopenia and osteoporosis who are at potential long-term risk for fracture.

MATERIALS AND METHODS

We reviewed our database of >200 individuals, who had undergone enterocystoplasty or continent diversion for both neurogenic and non-neurogenic reasons during childhood. We chose to study the non-neurogenic group first for a number of technical reasons, and identified 24 individuals who had undergone the procedure for non-neurogenic reasons, and had more than 15 years of follow-up. In addition we had a control group of 10 individuals born with bladder exstrophy, who had undergone primary closure before the year 2000, without enterocystoplasty. We used DEXA scan T- and Z-scores to identify patients with osteopenia and osteoporosis.

RESULTS

Eleven of 24 patients had normal DEXA scans with normal T- and Z-scores; seven had identifiable osteopenia and increased long-term risk for fracture. Six had osteoporosis; three of whom had reduced glomerular filtration rate (GFR). Eight of the 10 individuals in the control group had a normal DEXA scan.

CONCLUSIONS

Enterocystoplasty during childhood can lead to loss of BMD. This does not seem to be related to the enterocystoplasty alone. It is more pronounced in individuals who have other risk factors, such as reduced GFR. The identification of BMD loss makes it possible to intervene before osteoporosis occurs and leads to pathologic fracture.

Bricker Conduit for Pediatric Urinary Diversion--Should we Still Offer It?

PURPOSE

We sought to evaluate long-term outcomes of the Bricker conduit urinary diversion in children.

MATERIALS AND METHODS

We retrospectively reviewed the database of a single tertiary center for children who had undergone ileal conduit between 1981 and 2011. Patients followed for less than 1 year were excluded. Patient files were reviewed for demographics, diversion indication, preoperative imaging, surgical details, hospital readmissions and followup data. Renal function at baseline and last followup was assessed by estimated glomerular filtration rate, calculated using the modified Schwartz or MDRD (Modified Diet in Renal Disease) formula. Growth charts elucidated patient growth patterns, while an internally designed quality of life questionnaire demonstrated patient and family satisfaction with the procedure.

RESULTS

We evaluated 29 children who underwent Bricker conduit at a median age of 10 years (range 2 to 18) and were followed for a median of 91 months (16 to 389). Neuropathic bladder was the underlying diagnosis in 72.4% of cases. Hydronephrosis improved or remained stable in 39 of 55 studied renal units (70.9%). Although no statistically significant difference was observed between mean ± SD baseline (64.5 ± 46 ml/minute/1.73 m(2)) and last followup estimated glomerular filtration rate (54.1 ± 44.9 ml/minute/1.73 m(2)), chronic kidney disease stage had worsened in 13 patients (44.8%), end-stage kidney disease had developed in 11 patients and 9 patients had died. Six patients underwent undiversion after stabilization of renal function. Linear growth was negatively affected in 12 patients (41.4%), and 85% reported poor quality of life. A total of 19 hospital readmissions were required in 14 patients to treat diversion related complications.

CONCLUSIONS

The Bricker conduit does not seem to halt renal deterioration in children. Negative impact on growth and quality of life, and the anticipated rate of complications are significant limitations of the procedure in the pediatric population.

Bone and metabolic complications of urinary diversions

Hyperchloremic metabolic acidosis is a complication of urinary diversion using ileum or colon. Its prevalence ranges from 25% and 46% depending on the procedure used and renal function of the patient. It is a consequence of intestinal fluid and electrolyte exchange between intestinal mucosa and urine. The main mechanism is absorption of ammonium and chloride from urine. Long-term chronic metabolic acidosis in these patients may lead to impaired bone metabolism and osteomalacia. Regular monitoring of pH, chlorine, bicarbonate, and calcium-phosphorus metabolism is therefore essential for early diagnosis and treatment.

Risk of fracture after radical cystectomy and urinary diversion for bladder cancer

PURPOSE

Radical cystectomy and urinary diversion may cause chronic metabolic acidosis, leading to long-term bone loss in patients with bladder cancer. However, the risk of fractures after radical cystectomy has not been defined. We assessed whether radical cystectomy and intestinal urinary diversion are associated with increased risk of fracture.

PATIENTS AND METHODS

Population-based study using SEER-Medicare-linked data from 2000 through 2007 for patients with stage 0-III bladder cancer. We evaluated the association between radical cystectomy and risk of fracture at any site, controlling for patient and disease characteristics.

RESULTS

The cohort included 50,520 patients, of whom 4,878 had cystectomy and urinary diversion. The incidence of fracture in the cystectomy group was 6.55 fractures per 100 person-years, compared with 6.39 fractures per 100 person-years in those without cystectomy. Cystectomy was associated with a 21% greater risk of fracture (adjusted hazard ratio, 1.21; 95% CI, 1.10 to 1.32) compared with no cystectomy, controlling for patient and disease characteristics. There was no evidence of an interaction between radical cystectomy and age, sex, comorbidity score, or cancer stage.

CONCLUSION

Patients with bladder cancer who have radical cystectomy and urinary diversion are at increased risk of fracture.

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.

Long-term outcomes of urinary tract reconstruction in patients with neurogenic urinary tract dysfunction

The advent of specialized spinal units and better understanding of the pathophysiology of neurogenic urinary tract dysfunction has made long-term survival of these patients a reality. This has, in turn, led to an increase in quality and choice of management modalities offered to these patients including complex anatomic urinary tract reconstructive procedures tailored to the unique needs of each individual with variable outcomes. We performed a literature review evaluating the long-term outcomes of these reconstructive procedures. To achieve this, we conducted a world-wide electronic literature search of long-term outcomes published in English. As the premise of this review is long-term outcomes, we have focused on pathologies where evidence of long-term outcome is available such as patients with spinal injuries and spina bifida. Therapeutic success following urinary tract reconstruction is usually measured by preservation of renal function, improvement in quality-of-life, the satisfactory achievement of agreed outcomes and the prevention of serious complications. Prognostic factors include neuropathic detrusor overactivity; sphincter dyssynergia; bladder over distension; high pressure storage and high leak point pressures; vesicoureteric reflex, stone formation and urinary tract infections. Although, the past decade has witnessed a reduction in the total number of bladder reconstructive surgeries in the UK, these procedures are essentially safe and effective; but require long-term clinical and functional follow-up/monitoring. Until tissue engineering and gene therapy becomes more mainstream, we feel there is still a place for urinary tract reconstruction in patients with neurogenic lower urinary tract dysfunction.

Downstream complications following urinary diversion

PURPOSE

Surveillance following urinary diversion should be tailored to capture complications downstream from the initial reconstruction. Most analyses of the morbidity associated with urinary diversion are restricted to the index admission or the immediate postoperative period. We characterize the long-term medical and surgical complications and burden of health care use after urinary diversion.

MATERIALS AND METHODS

Using the 5% Medicare sample from 1998 to 2005 we identified individuals who underwent cutaneous and orthotopic continent urinary diversion, ileal conduit or other types of diversion including enterocystoplasty from physician claims for the index admission. We restricted our sample to subjects with claims 1 year before surgery and at least 2 years after the diversion. We included benign and malignant primary diagnoses, and evaluated the incidence of medical and surgical complications 2 and 5 years after surgery. We stratified complications by diversion type and compared long-term complications after urinary diversion surgery.

RESULTS

Of the 1,565 subjects identified 80% underwent ileal conduit urinary diversion, 7% underwent cutaneous or orthotopic continent diversion and 13% underwent other types of reconstruction. Urinary stone formation, wound complications and fistula complications were more common following continent diversion 5 years after surgery, while ureteral obstruction and renal failure/impairment were more common after ileal conduit diversion. Overall we estimated that more than 16% of patients experienced renal failure or impairment after urinary diversion.

CONCLUSIONS

Complications are common after urinary diversion and continue to occur through 5 years postoperatively. Urolithiasis and delayed wound complications appear to occur more commonly after continent diversion than after other urinary diversions. A large proportion of patients experience renal deterioration after diversion. These results highlight the need to survey patients for the diversion related complications of cystectomy as rigorously as we monitor for cancer recurrence.

Chronic kidney disease in patients with ileal conduit urinary diversion

While renal dysfunction is often observed in patients following urinary diversion due to bladder cancer, there have been few studies on this subject. A cross-sectional study was performed on the renal function of ileal conduit urinary diversion patients and the prevalence and risk factors for chronic kidney disease (CKD) were examined. Patients with ileal conduit urinary diversion (n=102), who were being followed-up as outpatients and who were in stable condition, as well as age- and gender-matched healthy control subjects (n=63) were selected for this study. The prevalence of CKD was compared between the patients and healthy subjects. Next, the clinical factors associated with the presence of CKD were investigated in the patients with ileal conduit diversion using logistic regression analysis. The prevalence of CKD was significantly higher in the patients with ileal conduit diversion compared with the healthy subjects [60 patients (58.8%) vs. 11 healthy subjects (17.5%), P<0.0001]. The mean decrease in the estimated glomerular filtration rate per year of the patients with urinary diversion was 0.95±2.0 ml/min/1.73 m². Multiple logistic regression analysis revealed that the independent and significant factors associated with the presence of CKD were older age and the presence of hypertension, urolithiasis and a past history of hydronephrosis. In conclusion, an increased prevalence of CKD was revealed in the patients with ileal conduit urinary diversion, suggesting the need for better management of hypertension, urolithiasis and hydronephrosis following surgery.

[Metabolic long-term complications after urinary diversion]

Metabolic long-term complications and consequences after urinary diversion are somewhat neglected. Subclinical metabolic disturbances are quite common; however, complications are rare. The absorptive surface of the bowel segment is lost for the physiological function of the gastrointestinal tract. Some studies demonstrated that at least some of the absorbent and secreting properties of the bowel are preserved if exposed to urine. For each bowel segment typical complications are reported. Using ileal and/or colon segments, hyperchloremic metabolic acidosis may occur. Studies demonstrated that metabolic effects are not as severe as suspected and could be prevented if a prophylactic treatment is started early.The resection of ileal segments is responsible for malabsorption of vitamin B(12) and bile acid; when using colonic segments, electrolyte disturbances are more common. Careful patient selection, meticulous follow-up and prophylactic treatment are crucial to prevent 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.

Osteoporosis in paediatric patients with spina bifida

The prevalence and morbidity associated with osteoporosis and fractures in patients with spina bifida (SB) highlight the importance of osteoporosis prevention and treatment in early childhood; however, the issue has received little attention. The method for the selection of appropriate patients for drug treatment has not been clarified.

OBJECTIVE

To review the literature concerning fracture risks and low bone density in paediatric patients with SB. We looked for studies describing state-of-the-art treatments and for prevention of secondary osteoporosis.

METHODS

Articles were identified through a search in the electronic database (PUBMED) supplemented with reviews of the reference lists of selected papers. The main outcome measures were incidence of fractures and risk factors for fracture, an association between bone mineral density (BMD) and occurrence of fracture, risk factors of low BMD, and effects of pharmacological and non-pharmacological treatments on BMD and on the incidence of fractures. We considered as a secondary outcome the occurrence of fractures in relation to the mechanism of injury.

RESULTS

Results indicated that patients with SB are at increased risk for fractures and low BMD. Risk factors that may predispose patients to fractures include higher levels of neurological involvement, non-ambulatory status, physical inactivity, hypercalciuria, higher body fat levels, contractures, and a previous spontaneous fracture. Limitations were observed in the number and quality of studies concerning osteoporosis prevention and treatment in paediatric patients with SB. The safety and efficiency of drugs to treat osteoporosis in adults have not been evaluated satisfactorily in children with SB.

Bone mineral density in children with myelomeningocele

The aim of the present study was to document bone mineral density (BMD) in children with myelomeningocele and to identify variables that contribute to reduced BMD. The study included 24 children with myelomeningocele (nine males, 15 females; age range 4-18y), who had varied levels of neurological impairment (thoracic/high-lumbar, n=6; mid-lumbar, n=9; sacral, n=9) and ambulatory status (non-ambulators, n=12; part-time ambulators n=2; full-time ambulators, n=10). BMD measurements of the femoral neck and whole body using dual energy X-ray absorptiometry assessments of dietary calcium intake, and serum markers of bone metabolism were obtained. BMD is presented as standardized scores (z-scores) which are age- and sex-matched to normally developing children. The mean femoral-neck z-score was -2.41. Femoral-neck z-scores differed significantly according to ambulatory status, with lower z-scores in children who were wheelchair-dependent (p=0.03). The mean z-score at the femoral neck demonstrated a trend toward lower z-scores in children with higher levels of lesions. Almost all children met their recommended daily intake of calcium. Markers of bone metabolism were normal in all patients. This study demonstrates that reduced BMD is a major complication in children with myelomeningocele. There is a significant relationship with low BMD in children who are wheelchair-dependent, a trend in those with higher neurological levels, and no relationship between fractures and reduced BMD.

Skeletal health after intestinal bladder augmentation: findings in 54 patients

OBJECTIVE

To evaluate the risk of osteopenia in patients after intestinal bladder augmentation.

PATIENTS AND METHODS

In all, 54 patients with bladder augmentation were evaluated during the regular follow-up programme. Augmentation was performed because of paediatric neurogenic or non-neurogenic reasons. Areal bone mineral densities (aBMD) for the lumbar spine (L1-L4), femoral neck and whole body were measured with dual-energy X-ray absorptiometry. In addition, acid-base balance and plasma 25-hydroxyvitamin D (vitamin D), kidney and gonadal functions as well as body mass index (BMI) were measured. Findings were correlated with clinical characteristics.

RESULTS

BMD was reduced in 34 (63%) of the 54 patients. There was a significant difference in the prevalence of decreased aBMDs between neurogenic and non-neurogenic groups 31 of 42 patients (74%) and three of 12 patients, respectively (P < 0.01). There were spinal compression fractures in 23% of patients. Risk factors for osteoporosis were inability to walk, renal insufficiency, hypogonadism, vitamin D deficiency, acidosis, and a low BMI. There was moderate or severe vitamin D deficiency in 42% of patients but the vitamin D status did not correlate with BMD. The glomerular filtration rate correlated to the whole-body aBMD (P = 0.04). In 26% of patients (predominantly males with myelomeningocele) plasma follicle-stimulating hormone levels were elevated, indicating variable degrees of hypogonadism. Hypogonadism was associated with reduced lumbar spine aBMD (P = 0.03).

CONCLUSION

Patients with paediatric reasons for bladder augmentation are at risk of osteopenia and compression fractures. The risk factors are mostly related to the patient's underlying illness and not to the augmentation per se.

Urinary Diversion

A consensus conference convened by the World Health Organization (WHO) and the Société Internationale d'Urologie (SIU) met to critically review reports of urinary diversion. The world literature on urinary diversion was identified through a Medline search. Evidence-based recommendations for urinary diversion were prepared with reference to a 4-point scale. Many level 3 and 4 citations, but very few level 2 and no level 1, were noted. This outcome supported the clinical practice pattern. Findings of >300 reviewed citations are summarized. Published reports on urinary diversion rely heavily on expert opinion and single-institution retrospective case series: (1) The frequency distribution of urinary diversions performed by the authors of this report in >7000 patients with cystectomy reflects the current status of urinary diversion after cystectomy for bladder cancer: neobladder, 47%; conduit, 33%; anal diversion, 10%; continent cutaneous diversion, 8%; incontinent cutaneous diversion, 2%; and others, 0.1%. (2) No randomized controlled studies have investigated quality of life (QOL) after radical cystectomy. Such studies are desirable but are probably difficult to conduct. Published evidence does not support an advantage of one type of reconstruction over the others with regard to QOL. An important proposed reason for this is that patients are subjected preoperatively to method-to-patient matching, and thus are prepared for disadvantages associated with different methods. (3) Simple end-to-side, freely refluxing ureterointestinal anastomosis to an afferent limb of a low-pressure orthotopic reconstruction, in combination with regular voiding and close follow-up, is the procedure that results in the lowest overall complication rate. The potential benefit of "conventional" antireflux procedures in combination with orthotopic reconstruction seems outweighed by the higher complication and reoperation rates. The need to prevent reflux in a continent cutaneous reservoir is not significantly debated, and this should be done. (4) Most reconstructive surgeons have abandoned the continent Kock ileal reservoir largely because of the significant complication rate associated with the intussuscepted nipple valve.

A comparison of engineered urinary bladder and intestinal smooth muscle for urinary bladder wall replacement in a rabbit model

BACKGROUND/PURPOSE

The small intestine is the most common resource for bladder augmentation. Little is known whether intestinal smooth muscle cells (SMCs) may be engineered into bladder tissue. We investigated the phenotypic and functional characteristics of engineered bladder and intestinal SMCs as bladder wall replacement in a rabbit model.

METHODS

One month after an initial 70% partial cystectomy, 3 autoaugmentation surgeries were performed, including traditional autoaugmentation (TA, n = 6), TA using engineered bladder SMCs (TA + B, n = 6), and TA using intestinal SMCs (TA + I, n = 6). All were followed up by bladder volume measurement and retrieved on the first, third, and sixth month. The grafts and the native bladder wall were evaluated with immunocytochemistry and electrical field stimulation (EFS). Statistical analysis was performed using analysis of variance.

RESULTS

Both the TA + I and TA + B groups showed significant and similar bladder capacity increment in all time points. The engineered muscle cells demonstrated the typical "contraction-relaxation" response to supramaximal EFS. There were no statistical differences in both the TA + I and TA + B groups in contractility force.

CONCLUSION

Engineered SMCs derived from urinary bladder and small intestine could retain their phenotype after implantation in vivo. Both exhibited a similar degree of contractility to EFS. These results suggest that there are no phenotypic or functional differences between muscle cells obtained from the 2 different organs. Both have the potential to be engineered into normal bladder tissues.

Evaluation of bone mineral density after ileocystoplasty in children with and without myelomeningocele

We evaluated the bone mineral density (BMD) after ileal augmentation cystoplasty in a group of children with and without myelomeningocele. Between 1996 and 2003, eight patients with neurogenic bladder and seven patients with non-neurogenic bladder underwent augmentation ileocystoplasty. Preoperative and postoperative serum creatinine and electrolytes were measured. All patients underwent clinical evaluation, supine height measurement, blood gas analysis, and BMD measurement using a dual energy X-ray absorptiometry (DEXA) postoperatively. BMD was measured at L1-L4 and femoral neck, and compared to age- and sex-matched population. Follow-up time was calculated from the day of surgery to the day of DEXA performance. A total of eight boys and seven girls with the mean age of 10.2 +/- 4.1 years were evaluated with respect to BMD measurement. Mean age was 9.8 years in neurogenic group and 10.5 in non-neurogenic group. Mean follow-up was 728 and 616 days in neurogenic and non-neurogenic groups, respectively. There were no significant differences between ages, follow-up times, preoperative and postoperative creatinine levels, pH and bicarbonate values, and supine heights. Mean BMD at L1-L4 was 55.7% in neurogenic group and 83.8% in non-neurogenic group. There was a statistically significant difference between the two groups (P = 0.02). Mean BMD at femoral neck was 72% in neurogenic group and 86.2% in non-neurogenic group. The difference was also statistically significant (P = 0.028). After augmentation ileocystoplasty, the BMD in early postoperative period of patients with myelomeningocele is lower than the patients with non-neurogenic neurogenic bladder, which have the same clinical characteristics except the neurologic pathology. In the light of our findings and the reported literature data as well, we may claim that BMD decrease after augmentation ileocystoplasty depends more on the underlying neurologic pathology and its locomotor consequences rather than the enterocystoplasty itself.

Osteoporosis in Adults With Meningomyelocele: An Unrecognized Problem at Rehabilitation Clinics

OBJECTIVES

To assess the prevalence of osteoporosis and osteopenia in adults with meningomyelocele and to explore whether neurologic level, ambulatory status, and other medical problems are associated with bone mineral density (BMD).

DESIGN

A cross-sectional study, including a self-administered questionnaire and clinical assessment.

SETTING

Outpatient referral clinic in Sweden.

PARTICIPANTS

Twenty-one adults (mean age, 30 y) with meningomyelocele admitted to the Young Adult Teams in Göteborg and Boras, Sweden.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BMD in the lumbar spine and hip and forearm measured with dual x-ray absorptiometry.

RESULTS

Seven (33%) subjects had osteoporosis in at least 1 of the measured sites. Three patients had osteopenia and 2 had osteoporosis in the lumbar spine. Among the 15 subjects whose BMD of the hip region could be reliably measured, 7 (47%) had osteoporosis in the femoral neck or trochanteric region of the hip. Subjects with other medical problems commonly occurring in meningomyelocele had lower BMD in the femoral neck and trochanteric region of the hip than subjects without such factors. Ambulation alone showed only a tendency to be associated with BMD of the femoral neck, whereas the effect of other medical risk factors on BMD of the femoral neck was stronger among the nonambulators than the ambulators.

CONCLUSIONS

Our results show that osteoporosis is a medical problem to be considered when treating and rehabilitating patients with meningomyelocele.

Bladder autoaugmentation using various biodegradable scaffolds seeded with autologous smooth muscle cells in a rabbit model

BACKGROUND/PURPOSE

The prolapsed mucosa after bladder autoaugmentation usually collapses, and the volume increment is limited. This study is aimed at evaluating the efficacy of autoaugmentation assisted with 2 different scaffolds, polyglycolic acid (PGA) mesh and small intestinal submucosa (SIS), seeded with autologous bladder smooth muscle cells in a rabbit model.

METHODS

One month after an initial 70% partial cystectomy, various autoaugmentation surgeries were performed. These procedures included traditional autoaugmentation (n = 6) and traditional autoaugmentation covered with PGA or SIS without cell seeding (N) (PGA-N, n = 6; SIS-N, n = 6) or covered with scaffolds seeded with autologous bladder smooth muscle cells (C) (PGA-C, n = 6; SIS-C, n = 6). All were followed up by bladder volume measurement and retrieved on 1, 2, 3, and 6 months. Statistical analysis was by analysis of variance.

RESULTS

A normal urothelial layer was maintained in all groups. Only PGA-C group showed a significant bladder capacity increment as compared with the other groups in all time-points (P = .001, .000, .000, and .001 at first, second, third, and sixth months, respectively). The PGA-C group showed grossly normal bladder wall with scattered smooth muscle bundles. The other groups had marked graft shrinkage with only unorganized muscle fibers.

CONCLUSION

Cell-seeded PGA polymer facilitates smooth muscle regeneration, offers sufficient bladder wall backup, and achieves satisfactory volume increment after the autoaugmentation with time. The collagen matrix, although seeded with cells, did not offer adequate mechanical support after the surgery.

Changes in bone structure after augmentation cystoplasty in chronic uraemic rats

OBJECTIVE

To investigate the effect of urinary diversion using several types of intestinal segments on cortical and cancellous bone structure of growing rats with renal insufficiency.

MATERIAL AND METHODS

In all, 110 female Sprague-Dawley rats (8 weeks old) had either a two-stage subtotal nephrectomy by removing five-sixths of the renal mass, or a sham operation. Except for a uraemic control group, all uraemic rats then had an enterocystoplasty using stomach, ileum or colon (20 animals per group). An additional group with colic augmentation received the bisphosphonate ibandronate. After 12 weeks, the left tibia was assessed using peripheral quantitative computed tomography and bone histomorphometry.

RESULTS

After subtotal nephrectomy all groups had approximately 30% less endogenous creatinine clearance. Renal failure alone or in association with gastric or colic augmentation induced only negligible changes in the mass and structure of cortical and cancellous tibial bone. In contrast, rats after ileal augmentation and renal failure had a significant reduction in cancellous bone mineral density (P < 0.05) whereas the reduction in trabecular bone area and volume was not statistically significant. Furthermore, ileocystoplasty caused a decrease in trabecular number and perimeter, increased trabecular separation and enlarged bone marrow space, whereas ileocystoplasty had no effect on cortical bone. The changes were not associated with alterations in serum pH. Ibandronate treatment in the colonic cystoplasty group increased trabecular bone mass and structural variables over the untreated colonic cystoplasty group.

CONCLUSIONS

These results suggest that cystoplasty using an ileal segment causes a decrease in bone mass and architecture in growing rats with mild uraemia. It remains open to question whether the results obtained from experimental animals can be directly extrapolated to the clinical situation.

METABOLIC CONSEQUENCES AND LONG-TERM COMPLICATIONS OF ENTEROCYSTOPLASTY IN CHILDREN: A REVIEW

PURPOSE

We summarize important metabolic consequences and long-term complications associated with enterocystoplasty with particular emphasis on the pediatric patient with genitourinary abnormalities.

MATERIALS AND METHODS

A directed MEDLINE literature review for metabolic and long-term complications following enterocystoplasty was performed. Information gained through the published literature and from our database was reviewed and summarized to provide the reader with a thorough review of the subject.

RESULTS

Bowel is not a perfect tissue for substitution or augmentation and its use to treat functionally and structurally compromised bladders is associated with several metabolic consequences and long-term complications. Metabolic acidosis is the most common metabolic abnormality seen. The rates and severity of these complications vary, although they may have a profound impact on patient quality of life after enterocystoplasty.

CONCLUSIONS

The metabolic consequences and long-term complications associated with enterocystoplasty are important clinical features of this intervention. Careful consideration should be given to them prior to pursuing enterocystoplasty.

Bladder, bowel and bones--skeletal changes after intestinal urinary diversion

Impaired bone metabolism following urinary diversion through intestinal segments has always been a controversial subject of unclear clinical relevance. Whereas the perpetuated pathophysiological considerations seem conclusive in theory, the role of acidosis and malabsorption is less clear in animal experimentation and, even more so, in the clinical reality of modern continent diversion. In hardly any of the available contemporary case series was overt derangement of the acid-base balance, rickets or osteomalacia encountered. No consistent changes in osteotropic serum parameters could be found with normal calcium and phosphate in all patients. The assumption that colonic reservoirs have a higher risk of developing metabolic bone disease could not be confirmed by clinical data. As early correction of base excess is easy and probably a common policy in patients with intestinal urinary reservoirs, it will be virtually impossible to further study the natural history of bone metabolism after urinary diversion. While there is no need for a bone specific follow-up in asymptomatic adults with a normal acid-base balance, particular attention should be paid to children and to all patients with impaired renal function.

Effect of Augmentation Cystoplasty on Bone Metabolism in Chronic Uremic Rats

PURPOSE

We examined the impact of urinary diversion using several types of intestinal segments on the bone metabolism of growing rats with renal insufficiency.

MATERIALS AND METHODS

A total of 110, 8-week-old Sprague-Dawley rats underwent 2-stage subtotal nephrectomy by removal of 5/6 of the renal mass or sham operation. Except for a uremic control group all uremic rats underwent enterocystoplasty using stomach, ileum or colon. An additional group with colic augmentation received the bisphosphonate ibandronate. Bone mineral density of the tibia and lumbar spine, serum analysis and urinary excretion of the bone resorption marker deoxypyridinoline were determined monthly for 12 weeks. At study termination bone ash weight, bone mineral analysis and serum osteotropic hormone levels were determined.

RESULTS

All groups undergoing subtotal nephrectomy had a decreased endogenous creatinine clearance of approximately 30%. The lowest gains in tibial and lumbar spine bone mineral density were observed in animals undergoing ileocystoplasty. Femoral calcium content was significantly decreased in uremic ileocystoplasty rats compared with uremic controls. These changes were not induced by alterations in serum pH, nor were they associated with accelerated bone resorption as assessed by deoxypyridinoline. Ibandronate prevented changes related to bone resorption and increased bone mass.

CONCLUSIONS

Our results suggest that cystoplasty using ileum segments can aggravate renal bone disease in growing rats with mild uremia. Since the acid-base state was unchanged, other properties of the interposed ileum segment must be responsible for the negative effect on bone metabolism.

Long-Term Evaluation of Metabolic Profile and Bone Mineral Density After Ileocystoplasty in Children

PURPOSE

We evaluated the long-term effects of ileocystoplasty on linear growth, serum electrolytes, acid-base profile and bone mineral density (BMD) in a group of neurologically intact children with a mean followup of 8.9 years.

MATERIALS AND METHODS

Between 1988 and 1997, 9 girls and 16 boys with a mean age of 6 years (range 1 month to 14 years) underwent ileocystoplasty for etiologies other than myelomeningocele and neuropathic bladder. Indications for ileocystoplasty were small noncompliant bladder secondary to bladder exstrophy in 12 cases, bladder outlet obstruction in 10 and post-partial cystectomy for rhabdomyosarcoma in 3. All patients underwent clinical evaluation, supine height measurement, serum electrolytes, arterial blood gases and BMD measurement using a fan beam dual energy absorpitometry scan. BMD was measured at L1-L4 and corrected for age and sex.

RESULTS

Followup ranged from 4 to 13 years (mean 8.9). Serum creatinine was normal in 20 of the 25 patients. All patients had normal supine height measurement with a mean of 45th (+/- 9) centile on growth charts. Serum electrolytes, calcium, phosphorus and arterial blood gases were normal in all patients. Mean BMD corrected for age and sex was 89 (+/- 10)%. BMD was normal in 17 of 25 (68%) patients. Mild reduction in bone density between 1 and 2 standard deviations below the age/sex mean was documented in 3 (12%) patients and the remaining 5 (20%) showed marked osteopenia of 2 or more standard deviations. Of the latter 5 patients 2 had increased serum creatinine, 1 had a history of radiotherapy for pelvic rhabdomyosarcoma and 2 had cloacal exstrophy and short bowel, all of which might have contributed to the osteopenia.

CONCLUSIONS

Ileocystoplasty for children with normal kidney function is not associated with alterations in serum electrolytes or arterial blood gases in the long term. However, 32% of patients showed variable degrees of reduction in BMD. Although marked reduction in BMD was associated with cofactors, 12% of patients had evidence of mild osteopenia in absence of those cofactors. We recommend routine preoperative and longitudinal followup BMD measurements for children undergoing intestinal bladder augmentation.

The effect of enterocystoplasty on bone strength assessed at four different skeletal sites in a rat model

The objective of the study was to investigate bone strength at four different skeletal sites in a chronic animal model of urinary diversion. Young male Wistar rats (120) were allocated randomly to four groups undergoing ileocystoplasty; ileocystoplasty and resection of the ileocecal segment; colocystoplasty; or sham operation (controls). After 8 months the lumbar vertebrae, femora, and tibiae were harvested at necropsy. Bone strength was assessed biomechanically at four different skeletal sites: vertebra L3, femoral middiaphysis, femoral neck, and distal femoral metaphysis. Bone mass and architecture were assessed using standard static histomorphometry of the proximal tibial metaphysis (trabecular bone volume [BV/TV]; trabecular number [Tb.N]) and ash weight. Statistically significant differences of biomechanical parameters between groups were observed at three skeletal sites with corresponding changes in tibial histomorphometry. Isolated ileocystoplasty resulted in decreased maximum load values of L3 (-16.4%; p < 0.0035) and a substantial reduction in tibial BV/TV (-34.7%; p < 0.05). Ileocystoplasty combined with resection of the ileocecal segment led to a significant loss of bone strength of L3 (-32.4%; p < 0.0015) and a dramatic reduction of tibial BV/TV (-45.9%; p < 0.01). Loss of tibial metaphyseal bone mass was predominantly caused by a decrease in Tb.N. (p < 0.01). Colonic augmentation had no significant effect on bone strength or histomorphometric values. In conclusion, this is the first experimental study to demonstrate the relevance of histomorphometrically proven bone loss after enterocystoplasty in terms of biomechanical variables.

Skeletal growth and long-term bone turnover after enterocystoplasty in a chronic rat model

OBJECTIVE

To investigate skeletal growth and bone metabolism in a chronic animal model of urinary diversion.

MATERIALS AND METHODS

Young male Wistar rats (120) were allocated randomly to four groups undergoing: ileocystoplasty, ileocystoplasty and resection of the ileocaecal segment, colocystoplasty, and controls. All animals received antibiotics for 1 week after surgery; half of each group remained on oral antibiotics. Bone-related biochemistry was measured in serum and urine. Dual-energy X-ray absorptiometry and peripheral quantitative computed tomography (pQCT) were used to determine bone mass ex vivo.

RESULTS

Most (90%) of the rats survived the study period (8 months); six rats died from bowel obstruction at the level of the entero-anastomosis and four had to be killed because of persistent severe diarrhoea. Vital intestinal mucosa was found in all augmented bladders. There were no differences in bone length and volume. Loss of bone mass was almost exclusively in rats with ileocystoplasty and resection of the ileocaecal segment (-37.5%, pQCT, P < 0.01). There was no hyperchloraemic metabolic acidosis or gross impairment of renal function. Hypomagnesaemia, hypocalcaemia and decreased insulin-like growth factor-binding protein 3 were the only significant findings on blood analysis. Deoxypyridinoline crosslinks in urine were higher in rats with an enterocystoplasty than in controls.

CONCLUSIONS

Enterocystoplasty in rats neither impairs skeletal growth nor bone quantity, but leads to significant loss of bone mass when combined with resection of the ileocaecal segment. Rarefaction of the trabecular network is confined to the metabolically highly active cancellous compartment, most likely as a consequence of intestinal malabsorption.

Evaluation of bone mineral density with dual x-ray absorptiometry for osteoporosis in children with bladder augmentation

BACKGROUND/PURPOSE

Osteoporosis can appear as a result of metabolic acidosis in patients with bladder augmentation and total bladder replacement. These patients must be monitored for early diagnosis and osteoporosis to avoid related complications such as fracture. The current method for diagnosis of osteoporosis mainly involves bone densitometry. Dual x-ray absorptiometry (DXA) provides bone mineral content and bone mineral density (BMD). The purpose of this report is to determine the value of BMD measurement with DXA in the diagnosis and follow-up of osteoporosis and evaluation of response to treatment in the patients with bladder augmentation and total bladder replacement.

METHODS

Six patients with bladder extrophy and neurogenic bladder underwent colocystoplasty, ureterocystoplasty, and total bladder replacement. The Sigmoid colon segment was used for colocystoplasty. DXA (Hologic 2000 DXA) was used for measuring bone mineral content and density. Results for lumbar spinal BMD were expressed as the average of L1 through L4 values. Each patient's BMD was compared with the mean BMD in the young normal population (T score) and in the age- and sex-matched group (Z score). But because our patients were children, BMD was evaluated according to Z score. Arterial blood gas analysis was obtained periodically with BMD measurement. Arterial blood pH and HCO(3) levels of the patients were compared with normal values, which ranged from 7.35 to 7.45 for pH and from 22 to 27 mmol/L for HCO3.

RESULTS

Arterial blood pH of 5 of 6 patients (83.3%) and HCO3 levels of all patients were low. Ten BMD measurements were obtained for 6 children. One patient underwent BMD measurement 3 times, 2 patients underwent twice, and the others once. Z scores of 4 of 6 patients (66.6%) were decreased. Blood pH, HCO3 level, and BMD of 2 patients increased after oral bicarbonate intake. Two patients had normal BMD. One of these patients had ureterocystoplasty. The other had undergone colocystoplasty but was incontinent.

CONCLUSIONS

Intestinal segments have been used for bladder augmentation and total bladder replacement. Exposure of highly absorptive intestinal mucosa to urine has been associated with electrolyte abnormalities and metabolic acidosis. Hyperchloremic acidosis leads to bone demineralization. DXA provides bone mineral content and BMD for diagnosis of osteoporosis. DXA is preferred because the low radiation dose (average, 2 to 4 mrem), accuracy, low price, and short examination time. Not only can BMD confirm the diagnosis of osteoporosis, but it also can be used to monitor the course of the disease and the effectiveness of treatment.

Enterocystoplasty in childhood: a second look at the effect on growth

OBJECTIVE

To re-evaluate the assumption that enterocystoplasty in children has a detrimental effect on linear growth (which is almost exclusively based upon a chance finding in a retrospective study 10 years ago) in a larger cohort and with a longer follow-up.

PATIENTS AND METHODS

The original 12 children who had impaired linear growth in a previous study 10 years earlier were re-measured. A larger cohort was identified from the 242 children and adolescents who had undergone enterocystoplasty between 1982 and 1997. Patients with conditions involving organ systems apart from the urinary tract, and those with myelomeningocele, malignant diseases, reduced glomerular filtration rate and incomplete notes were excluded. In the definitive study cohort (123; mean age at operation 8.6 years; mean age at investigation 16.8 years) enterocystoplasty had been undertaken using colon in 70, ileum in 37, a combination of both in 11, ileocaecal segments in three and stomach in two patients.

RESULTS

Of the original 12 patients, six had regained or surpassed their preoperative position on their growth charts. In all patients with a known target centile range the final height was within their genetic growth potential. In the cohort of 123 patients, 1215 height and weight measurements had been recorded. The distribution of percentile positions before and after enterocystoplasty showed a normal configuration, with 83% and 80% of patients growing within two standard deviations of the 50th percentile. After surgery, 85% either remained on the same or reached a higher centile. Nineteen (15.5%) were in a lower position, with a similar tendency in the weight centile. A clinically relevant growth disorder was recognized in four patients with a complete endocrinological evaluation; in none of these was enterocystoplasty thought to be a causal factor.

CONCLUSIONS

It is very unlikely that the loss of the preoperative percentile position on the growth curve in 15% of children after enterocystoplasty is a consequence of the surgery. Rather it is a non-specific phenomenon that has to be considered in any clinical population of the same size and age distribution after the same length of time.

Growth and metabolic consequences of bladder augmentation in children with myelomeningocele and bladder exstrophy

OBJECTIVE

Bladder augmentation using intestinal segments is reported to cause decreased linear growth in bladder exstrophy and myelomeningocele patients. We studied changes in calcium metabolism, height, bone chemistry, and bone density in exstrophy and myelomeningocele patients after bladder augmentation.

METHODS

Thirty-three patients were prospectively admitted to the Pediatric Clinical Research Center at the University of California San Francisco for 24 hours. Blood and urine were analyzed for electrolytes, and serum was obtained for markers of calcium metabolism. Dual radiograph bone densitometry of the forearm was performed. Myelomeningocele patients were compared with nonaugmented myelomeningocele patients matched by age, gender, level of defect, and ambulatory status. Exstrophy augmented patients were compared with nonaugmented exstrophy patients. The bone densities in both groups were compared with normal children. Laboratory values and percentile heights were statistically analyzed using the Student t test; bone densitometry was analyzed using the Tukey test.

RESULTS

Twenty-two patients with myelomeningocele and 11 with bladder exstrophy were studied. Mean follow-up was 3.7 years postaugmentation (range: 1-13 years). The results indicate a significant difference in serum bicarbonate and chloride levels between myelomeningocele patients who underwent ileal augmentation and those who did not. Although this may be indicative of chronic metabolic acidosis, there was no affect on growth or bone density when compared with controls. There were no other significant differences in laboratory values, or percentile heights, nor were any differences noted in patients who underwent gastrocystoplasty. In the exstrophy group, there were no observable differences in percentile height or laboratory values between the augmented and nonaugmented group. There were no significant differences in bone density between these 2 groups when matched for age and gender. No significant difference was seen in bone density when these groups were compared with normal children.

CONCLUSION

Bladder augmentation is safe and does not impact negatively on the linear growth or bone densities of patients with myelomeningocele or bladder exstrophy.

Surgical management of overactive bladder

The majority of patients with overactive bladder (OAB) can be managed with office-based techniques. When medical therapy fails as treatment for OAB, surgical intervention ranging from electric stimulation administered in the office to extensive procedures, such as augmentation or urinary diversion, may be needed. Any surgical intervention should be tailored to the patient with consideration of the degree of his or her discomfort, underlying pathology, general health, and obviously, the patient's own motivation.

Plasticity of the urothelial phenotype: effects of gastro-intestinal mesenchyme/stroma and implications for urinary tract reconstruction

The present study tests the hypothesis that heterotypic stromal-epithelial interactions cause phenotypic changes in urothelium. The rational for the experimental design is to simulate heterotypic stromal-epithelial interactions that are created at the anastomotic site of intestinal-bladder augmentations and internal urinary diversions where the urothelium is in direct contact with the gastro-intestinal tract tissues. Tissue recombination experiments were performed by combining 14-day embryonic rat and mouse rectal mesenchyme with urothelium from embryonic, newborn, and adult mice or rats. All tissue recombinants were grown beneath the renal capsule of athymic mouse hosts for 6-16 weeks. Analyses were performed to detect expression of uroplakins, cytokeratin 7, 14, 19 and mucin secreting epithelial cells via Periodic Acid-Schiff (PAS). The phenotype of both mouse and rat urothelium was changed to a glandular morphology under the influence of rectal mesenchyme. Immunohistochemical staining revealed a loss of the urothelial specific uroplakins and cytokeratins 7, 14, and 19 (characteristic of urothelium). Histologic analysis revealed the presence of mucin secreting glandular structures which stained positive for PAS. The urothelial transdifferentiation into glandular epithelium was not a function of epithelial age and occurred in the embryonic, newborn and adult urothelium. Likewise, rectal mesenchyme from embryonic, neonatal, and adult animals was able to induce glandular differentiation in bladder epithelium. Urothelium exhibits the plasticity to change into an intestinal like epithelium as a result of mesenchymal/stromal stimulation from the gastro-intestinal tract. This experimental result is germane to heterotypic stromal-epithelial interactions that are created in patients with urinary tract reconstructions (intestinal augmentations, de-mucosalized urothelial lined bladder patches, and internal urinary diversion such as ureterosigmoidostomies). We propose that heterotypic stromal-epithelial interactions may play a role in determining histodifferentiation of urothelial cells at the anastomotic site between bowel and bladder tissue in patients with gastro-intestinal urothelial reconstructions.

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.

Urinary diversion and bladder substitution in patients with bladder cancer

For the majority of patients with invasive bladder carcinoma, radical cystectomy remains the gold standard of care. As a result the twentieth century has seen the continuous development of methods for reconstructing the urinary tract. Two decades ago the ileal conduit was by far the most commonly used method, whereas today methods geared toward patient continence are first choices in most centers. Some of these methods are unquestionably more complex than the ileal conduit, yet whether they actually yield uniformly improved quality of life is the cause of much debate. Many different variables play a role in determining the best type of reconstruction for an individual bladder cancer patient. This review analyzes the different factors that must be considered to obtain an optimal match between patient and reconstructive method.

Determinants of bone loss in patients with Kock ileal urinary reservoir

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