The rationale behind recommendations for follow-up after urinary diversion: an evidence-based approach

Prevalence of metabolic acidosis in ileal diversions more than one year after radical cystectomy and associated secondary metabolic effects

INTRODUCTION AND OBJECTIVE

Metabolic acidosis (MA) is a well-known complication in patients with ileal urinary diversions. It is common in the early postoperative stages and decreases over time. Our objective is to investigate the prevalence of MA after more than one year of follow-up, identify the associated risk factors, and analyze its secondary metabolic consequences.

MATERIALS AND METHODS

We conducted an observational study between January 2018 and September 2022 following the STROBE guidelines. MA was defined as a serum bicarbonate level ​​<22mEq/L. Finally, we analyzed 133 patients with a mean follow-up of 55.24 ± 42.36 months.

RESULTS

MA was observed in 16 (12%) patients. Patients with and without MA were comparable in age, sex, and follow-up time. The group with MA presented a higher rate of anemia (68,75% vs 19,65%, p < 0.001) and renal failure (100% vs 45,29%, p < 0.001), statistically significant higher levels of serum creatinine, chloride, potassium, parathyroid hormone, and phosphorus but lower serum values ​​of hemoglobin, renal glomerular filtration rate, total cholesterol, vitamin D, calcium, and albumin (all p < 0.05). Renal glomerular filtration rate was the only independent risk factor related to the development of MA (OR 0.914; 95% CI 0.878-0.95; p < 0.0001), proving a close correlation with venous bicarbonate values ​​(r = 0.387, p < 0.001).

CONCLUSIONS

MA is a little prevalent disorder in ileal urinary diversions more than one year after radical cystectomy is performed but it has secondary consequences on hematologic, renal, protein, lipid, and bone metabolism. We recommend to a close follow-up in patients with renal failure for early diagnosis and treatment.

Metabolic acidosis after ileal urinary diversion and radical cystectomy. Do we know as much as we think we do? A systematic review

Urine contact with the mucosa of the urinary diversion (UD) after radical cystectomy (RC) produces different ion exchanges that favor the development of metabolic acidosis (MA). This phenomenon is a frequent cause of hospital readmission and short/long-term complications. We performed a systematic review of MA in RCs with ileal UD, analyzing its prevalence, diagnosis, risk factors and treatment. We systematically searched Pubmed® and Cochrane Library for original articles published before May 2022 according to PRISMA guidelines. A total of 421 articles were identified. We selected 25 studies that met the inclusion criteria involving 5811 patients. Obtaining precise data on the prevalence of MA is difficult, largely due to the heterogeneity of the diagnostic criteria used given the diversity of studies analyzed. Development of MA is multifactorial. In the early period, MA is more prevalent in patients with UD with longer ileal segments, better urinary continence, and impaired renal function. Age and diabetes are risk factors associated with MA in later periods. MA is the most common cause of second or more hospital readmissions. Prophylaxis with oral bicarbonate for three months in patients at risk could improve these results. Although MA after ileal UD is a well-known condition, this review highlights the need to implement homogeneous criteria for the diagnosis, follow-up, and treatment, in addition to protocolizing prevention/prophylaxis strategies in patients at risk.

Cost comparison of intra-detrusor injection of botulinum toxin versus augmentation cystoplasty for refractory neurogenic detrusor overactivity in children

INTRODUCTION

Treatment options for refractory neurogenic detrusor overactivity (NDO) in children include botulinum toxin type A (BTX-A) and augmentation cystoplasty (AC). Although BTX-A is accepted in contemporary pediatric urologic practice, cost and long-term outcomes data for BTX-A are limited relative to the gold standard, AC. The purpose of this study was to compare the projected 10-year costs of AC versus BTX-A.

METHODS

We performed a cost analysis from the payer perspective by computationally modeling treatment sequences by a Markov model. In the model, we used probabilities derived from published sources, and costs obtained at a tertiary medical center. The base case was a pediatric patient with refractory NDO. In the model, we assumed biannual BTX-A treatments. Treatment costs over 10 years were compared between immediate AC versus bridging therapy with BTX-A. Using the computational model, we simulated 100,000 instances of 10-year treatment cost for each of the two treatment modalities. The costs for the two treatment approaches were then compared using t-test and Wilcoxon test.

RESULTS

The projected median and mean 10-year cost of immediately AC were $51,798.72 (95% CI [$51,798.72, $327,483.80]) and $123,473.4 (SD: $98,085.23) respectfully, while the projected median and mean 10-year cost of bridging therapy with BTX-A prior to proceeding to AC as needed were $74,552.46 (95% CI [$53,188.56, $309,913.07]) and $124,858.80 (SD: $84,495.35) (p < 0.001).

CONCLUSIONS

For a typical index pediatric patient with NDO, bridging therapy with intravesical BTX-A is associated with an increased cost compared to immediate AC over a ten-year period.

Follow-up Management of Cystectomy Patients

Bladder cancer is the sixth leading cancer in the United States. Radical cystectomy is a lifesaving procedure for bladder cancer with or without muscle invasion. Radical cystectomy is performed on 39% of these patients, and 35% will have a life-threatening recurrence. Distant metastases are the most common; local, upper tract, and urethral recurrence can also occur. Surveillance after cystectomy is critical to diagnosing recurrence early. Functional complications after urinary diversion include bowel dysfunction, vitamin B12 deficiency, acidosis, electrolyte abnormalities, osteopenia, nephrolithiasis, urinary tract infections, renal functional decline, and urinary obstruction, which can be reversed when diagnosed early.

Metabolic and Electrolyte Abnormalities Related to Use of Bowel in Urologic Reconstruction

Many urologic reconstructive techniques involve the use of autologous bowel for urinary diversion and bladder augmentation. The resection of bowel and its reimplantation into the urinary system often comes with a variety of metabolic and electrolyte derangements, depending on the type of bowel used and the quantity of urine it is exposed to in its final anatomic position. Clinicians should be aware of these potential complications due to the serious consequences that may result from uncorrected electrolyte disturbances. This article reviews the common electrolyte complications related to both bowel resection and the interposition of bowel within the urinary tract.

Acid-base disorders after orthotopic bladder replacement: comparison of an ileal neobladder and an ileal conduit

Objectives: For many years, creation of an orthotopic neobladder after cystectomy has been popular. In the present study, we measured the extent of metabolic acidosis in patients with ileal neobladders compared with ileal conduits and defined risk factors for development of metabolic acidosis.

Methods: We retrospectively studied 95 patients, who underwent radical cystectomy and urinary diversion to treat invasive bladder cancer from January 2001 to December 2014 at Hallym University Kangnam Sacred Heart Hospital, through investigation of acid-base balance, serum electrolyte levels and renal function one month and one year after operation.

Results: One month after the operation, metabolic acidosis was found from 18 patients (31.0%) in an ileal neobladder group and from 4 (14.8%) in an ileal conduits group. One year after the operation, the numbers became 11 (22.9%) and 2 (10.0%), respectively. However, there was not a statistical difference. The blood biochemical profiles of the two groups did not differ significantly after urinary diversion. Logistic analysis revealed that lower estimated glomerular filtration rate (eGFR) was associated with metabolic acidosis at one month (odds ratio, OR = 0.94 [0.91–0.97]; p < 0.001) and one year (OR = 0.94 [0.92–0.97]; P = 0.001) after urinary diversion. In multivariate analysis, lower eGFR is a significant risk factor for metabolic acidosis at one month.

Conclusions: Patients with ileal neobladders and conduits are at the similar risk of metabolic acidosis. A close association between renal function and development of metabolic acidosis was observed, especially stronger in an early period after operation.

Is chronic alkali therapy in orthotopic ileal neobladders necessary? A prospective controlled study

PURPOSE

To evaluate the necessity of chronic alkali therapy in non-complicated orthotopic ileal neobladders with normal renal function.

MATERIALS AND METHODS

This is a prospective study that included 200 male patients who underwent radical cystectomy and ileal W neobladder for invasive bladder carcinoma between January 1993 and December 2013. The studied patients included 100 consecutive patients who were maintained on regular alkali therapy since surgery and 100 consecutive patients who stopped the use of alkali treatment after initial 3 months postoperative with minimum postoperative observation time of 1 year. All patients had satisfactory function of the reservoirs with normal upper tract. The patients were subjected to blood analysis for creatnine, electrolytes, pH and bicarbonate and urine chemical analysis. The study also included 40 healthy male age-matched volunteers who served as a control group.

RESULTS

Both groups were comparable as regard age, BMI, follow-up period and surgical technique. There were no significant differences between both groups as regard serum creatnine, electrolytes blood pH and bicarbonate and the mean values were within normal range; however, the neobladder patients are still toward the acidotic side in comparison to healthy volunteers. Also there were no significant differences between both groups of patients as regard urine pH and excretion of electrolytes, calcium, phosphorus and creatnine.

CONCLUSION

Patients with non-complicated ileal neobladders with normal upper tract who were not maintained on alkali prophylaxis for long period have a compensated acid base status. Therefore, the prolonged alkali prophylaxis is not mandatory.

Urostomy and health-related quality of life in patients with lower urinary tract dysfunction

OBJECTIVE

Urinary diversion may be an option in patients with disabling lower urinary tract dysfunction (DLUTD), refractory to conservative and minor invasive treatment. The aim of this study was to evaluate whether urostomy improves quality of life and cost of surgery, in terms of complications, loss of kidney function and hospital stay, in these patients.

MATERIAL AND METHODS

This prospective study included 52 consecutive patients (nine men and 43 women) with various benign disorders. Twenty-six patients received an ileal conduit and 26 a continent cutaneous diversion. The patients completed the general health-related quality of life instrument WHOQOL-BREF and a urinary problem-specific quality of life instrument preoperatively and 6 and 12 months after surgery. Length of hospital stay and complications were registered. Intravenous urography and determination of glomerular filtration rate (GFR) were performed preoperatively and 12 months postoperatively.

RESULTS

Disease-specific and health-related quality of life improved significantly (p < 0.0005 and p < 0.05) in all domains except for social relationship, from preoperative to 12 months after surgery. There was no difference in improvement between patients with continent and those with incontinent diversion. Mean hospital stay was 14 days. Early and late complications required open surgery in 12 patients (23%). GFR was unchanged postoperatively.

CONCLUSIONS

Urinary diversion improves health-related and disease-specific quality of life in patients with DLUTD refractory to conservative and minor invasive treatments. The burden of surgery is acceptable. Urinary diversion could be recommended more often in such patients.

Functional results after orthotopic bladder substitution: a prospective multicentre study comparing four types of neobladder

OBJECTIVE

The aim of this study was to evaluate enterocystometry, voiding pattern and urine leakage of four types of orthotopic bladder substitute.

MATERIAL AND METHODS

At eight urological departments, 78 consecutive men were studied: 66 with an ileal neobladder [30 Studer pouches (S), 24 Hautmann pouches (H) and 12 T-pouches (T)] and 12 with a right colonic [Goldwasser type (G)] neobladder. Enterocystometry, determination of residual urine, micturition protocol and 24 h pad weight test were performed 6 and 12 months postoperatively.

RESULTS

Colonic neobladders had higher pouch pressure at first desire, normal desire and strong desire than ileal neobladders (except at first and normal desire at 12 months) (p < 0.02) and contraction was present more often at both 6 and 12 months (p < 0.01 and p < 0.01). Compliance was good in all types of pouch. Intermittent self-catheterization was more common in H patients at 6 months (p = 0.033). All patients with colonic neobladders used pads during the day and night. In patients with ileal pouches 32% used pads during the day and 70% during the night at 12 months. Urine leakage was higher in patients with colonic bladders at 6 and 12 months during the day (mean/median of 98/31 ml and 82/16 ml versus 10/0 ml and 4/0 ml, p < 0.001). T-pouches had excellent day-time continence, but nocturnal leakage was high.

CONCLUSIONS

The Hautmann pouch and the Studer pouch behaved similarly at enterocystometry and clinically, and continence was good in the majority of patients. The low number of patients with the other two types of pouch precludes definitive statements.

[Patients' acceptance of urinary diversion. The pouch of Sisyphus]

It is important that any patient with a urinary diversion can accept the psychological impact alongside the surgical and physical aspects. However, there are currently no validated methods or instruments available to allow direct measurement of this phenomenon in these patients. Health-related quality of life (HRQoL) is often high following different types of urinary diversion-this may suggest a high acceptance level and thus may act as a secondary end point. Such an assessment is a retrospective validation of successful patient selection, allowing us to redirect the nihilistic misinterpretation that urologists should return to offering ileal conduits as a standard. In modern urinary diversion, high patient acceptance develops from comprehensive counselling providing a realistic expectation, careful patient-to-method-matching, strict adherence to surgical detail during the procedure and a meticulous lifelong follow-up. Coping strategies, disease-related social support and confidence in the success of treatment are among other factors which contribute to acceptance of urinary reconstruction as either independent or combined factors. Significant experience is required in every respect, as misjudgement and mistakes in any of these issues may be detrimental to the patients' health. It should be acknowledged that there is no 'best' urinary diversion in general terms. A reconstructive surgeon must have all techniques available and choices need to be tailored to the individual patient.

Metabolic changes after urinary diversion

Urinary diversion is performed on a regular basis in urological practice. Surgeons tend to underestimate the metabolic effects of any type of diversion. From the patient's perspective, diarrhea is the most bothersome complaint after urinary diversion. This might be accompanied by malabsorption syndromes, such as vitamin B12 deficiency. Electrolyte abnormalities can occur frequently such as hyperchloremic metabolic acidosis, or less frequently such as hypokalemia, hypocalcaemia, and hypomagnesaemia. Bone health is at risk in patients with urinary diversion. Some patients might benefit from vitamin D and calcium supplementation. Many patients are also subject to urinary calculus formation, both at the level of the upper urinary tract as in intestinal reservoirs. Urinary diversion can affect hepatic metabolism, certainly in the presence of urea-splitting bacteria. The kidney function has to be monitored prior to and lifelong after urinary diversion. Screening for reversible causes of renal deterioration is an integral part of the followup.