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

Early and late post-procedural complications in different orthotopic neobladder surgical approaches: A systematic review

Bladder cancer (BCa) represents the second most common malignancy of the genitourinary tract. The major risk factors include age, gender, smoking attitude, and occupational exposure, while the exact etiopathogenesis is still uncertain. Patients diagnosed with a BCa showing invasion of the muscle layer below the submucosa must undergo radical cystectomy (RC) with urinary diversion (UD). Many different surgical approaches to UD have been developed. Packaging an orthotopic neobladder (ON) with a bowel tract represents the gold standard when certain patient selection criteria are satisfied. Using PRISMA guidelines, we performed a systematic review assessing early (within 90 days) and late (beyond 90 days) post-procedural complications of different ON surgical approaches. A comprehensive systematic search was conducted in PubMed, Scopus, and Google Scholar databases to identify papers starting from 2012 using dedicated keywords ("neobladder", "orthotopic neobladder", "complications'' and "outcomes"). A total of 27 articles were found to satisfy the inclusion criteria and selected. Although the ON is a safe procedure that guarantees the patient the best quality of life (QoL), it is not free from risks. Many complications could occur during and after the surgical time which imposes the necessity of strict follow-up and careful checks over time, which should be properly discussed with patients before.

Why do patients with urinary diversions have an increased risk of bone fracture? A systematic review on risk factors for osteoporosis and bone mineral density loss in this group of patients

INTRODUCTION

Patients undergoing radical cystectomy with urinary diversions (UD) are at increased risk of bone fractures compared to the general population. Although a loss of bone mineral density (BMD) has been described in patients with UD, we still do not know with certainty why these patients follow this tendency.

OBJECTIVE

We performed a systematic review of the available literature to analyze the prevalence of osteoporosis and bone alterations in patients with ileal UD and the possible associated risk factors.

EVIDENCE ACQUISITION

We systematically searched PubMed® and Cochrane Library for original articles published before December 2022 according to PRISMA guidelines.

EVIDENCE SYNTHESIS

A total of 394 publications were identified. We selected 12 studies that met the inclusion criteria with 496 patients included. Six of the twelve studies showed decreased BMD values. Prevalence of osteoporosis was specified in three articles, with values ranging ​​from 0% to 36%. Risk factors such as age, sex, body mass index, metabolic acidosis and renal function appear to have an impact on bone tissue reduction, while type of UD, follow-up, 25-hydroxyvitamin D and parathormone had less evidence or contradictory data. The heterogeneity of the studies analyzed could led to interpretation bias.

CONCLUSIONS

UD are associated with multiple risk factors for osteoporosis and bone fractures. Identifying patients at highest risk and establishing diagnostic protocols in routine clinical practice are essential to reduce the risk of fractures and the resulting complications.

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.

Detailed Description of the Karolinska Technique for Intracorporeal Studer Neobladder Reconstruction

In the last two decades, surgical techniques for intracorporeal urinary diversion have been developed with the aim of reducing surgical morbidity. Although increasing constantly, the numbers of urologists offering intracorporeal neobladder reconstruction remain limited due to the complex nature of the procedure. In this article, we aim to provide a detailed description of the surgical technique we currently use at our institution. This technique was initially developed and perfected at the Karolinska Institutet in Sweden starting in 2003. It is a reproducible surgical approach with standardized and well-defined surgical steps. We give a detailed description of the surgical steps and provide tips and tricks to address specific situations and to increase efficiency. We also review the indications, the preoperative considerations, equipment necessary, postoperative considerations, and clinical outcomes for this procedure. Finally, we provide an accompanying didactic surgical video. We believe that this standardized approach can be learned and reproduced safely by motivated robotic surgeons.

Neobladder creation in patients with chronic kidney disease: A viable diversion strategy

INTRODUCTION

Renal function impairment is often cited as a contraindication to continent diversion strategies. There is little evidence exploring renal function changes between continent and incontinent surgery in patients with preoperative chronic kidney disease (CKD), in particular CKD3B.

METHODS

This was a retrospective review of two high-volume centers performing robotic assisted radical cystectomy (RARC) with orthotopic neobladder (ONB) or ileal conduit (IC) between 2014 to 2020. Patients were stratified based on CKD estimated glomerular filtration (eGFR) stage, which was estimated via the CKD-EPI equation. Postoperative renal function was compared for up to 60 months postoperative. Surgical, post-surgical, complications, and readmission data were gathered and compared between all patients RESULTS: 522 cystectomy patients, 430 with IC and 125 with ONB, were included. eGFR decline was statistically significant in a matched cohort of IC and ONB patients only at 3 months. There were no statistically significant differences between readmission rates, time to readmission, or complications. 34.6% of stage 3B patients had hydronephrosis on imaging prior to surgery, compared to 11.4%, 22.1% and 21.8% of CKD stage 1, 2, and 3A patients. CKD stage 3B had statistically and clinically improved eGFR through 24 months.

CONCLUSION

ONB surgery may be a viable diversion strategy in patients previously thought to be contraindicated due to low renal function.

Hyperchloremic Metabolic Acidosis with Hyperglycemic Hyperosmolar Syndrome after Robot-Assisted Radical Cystoprostatectomy with Ileal Conduit Urinary Diversion: A Case Report

Hyperchloremic metabolic acidosis can be a problem in urinary diversion using the ileum. A 73-year-old Japanese male was hospitalized in emergency due to anorexia and malaise 3 weeks after being discharged from the hospital after getting robot-assisted radical cystoprostatectomy and intracorporeal ileal conduit urinary diversion. The blood analysis revealed metabolic acidosis, elevated chloride ions, and marked hyperglycemia: he was diagnosed with hyperchloremic metabolic acidosis and hyperglycemic hyperosmolar syndrome. We started administering insulin and large amounts of fluid replacement; besides, we inserted a large-diameter open tip catheter into the ileal conduit in hopes of inhibiting urine reabsorption in the intestinal mucosa. His general condition gradually improved, and he was discharged 10 days after his hospitalization.

Studying the electrolyte changes in ileal urine at the time of radical cystectomy and ileal conduit diversion

To the Editor, Radical cystectomy (RC) for bladder cancer is a life-changing surgery, associated with high morbidity and mortality rate. Ileal neobladder seems as an attractive way for urine management post cystectomy but would carry the risk of retaining urine in the ileal pouch for a long time, resulting in serum electrolyte changes, that may add to the patients' morbidity. EAU guidelines recommend against ileal neobladder for patients with liver and renal disorders, as well as for patients > 80 years old [...].

[Metabolic acidosis in neobladder patients : Risk factors and treatment options]

BACKGROUND

In cystectomy patients who underwent neobladder creation, the intestinal mucosa of the neobladder is in constant contact with urine, which may result in chronic metabolic acidosis (CMA) due to specific absorption capabilities of the intestinal mucosa. Despite being a prevalent comorbidity, the risk factors for CMA and its diagnostic parameters are poorly understood.

OBJECTIVES

This review examines the risk factors associated with the development of CMA and their prevalence in patients with a neobladder.

MATERIALS AND METHODS

We conducted a systematic literature search using the PubMed database to detect studies about the topics CMA and neobladder that were published between 2000 and 2020. The prevalence and risk factors for CMA in neobladder patients were assessed by reviewing 23 studies.

RESULTS

Acidosis is most prevalent during the first year after surgery (25-70%). Risk factors are renal failure, high continence, old age and diabetes mellitus.

CONCLUSIONS

The prevalence of CMA is at its highest during the early postoperative period for neobladder patients, so for this time period, weekly diagnostic investigations are recommended according to the German S3-guidelines for the "Früherkennung, Diagnose, Therapie und Nachsorge des Harnblasenkarzinomsent für Neoblasepatienten". Blood gas tests should not only be used to analyze the pH value but also to detect and counteract acid-base imbalance issues in time. The recommended normalization of serum bicarbonate levels with oral bicarbonate follows patient-specific therapy strategies.

A systematic review and meta-analysis of the long-term outcomes of ileal conduit and orthotopic neobladder urinary diversion

INTRODUCTION

We aimed to perform a systematic review and meta-analysis on the long-term durability, incidence of complications, and patient satisfaction outcomes in ileal conduit (IC) and orthotopic neobladder (ONB).

METHODS

A systematic electronic literature search was performed in Medline, Embase, Cochrane Library, and Scopus using MeSH and free-text search terms "Urinary diversion" AND "Ileal conduit" AND "Neobladder." The search concluded June 19, 2018. Inclusion criteria were those patients who had a cystectomy and required urinary diversion by either IC or neobladder.

RESULTS

In total, 32 publications met the inclusion criteria. Data were available on 46 787 patients (n=36 719 for IC and n=10 068 for ONB). Meta-analyses showed that IC urinary diversions performed less favorably than ONB in terms of re-operation rates, Clavien-Dindo complications, and mortality rates; odds ratios (ORs) and 95% confidence intervals (CIs) were 1.76 (1.24, 2.50), p<0.01; 1.16 (1.09, 1.22), p<0.01; and 6.29 (5.30, 7.48), p<0.01, respectively. IC urinary diversion performed better than ONB in relation to urinary tract infection rates and ureteric stricture rates, OR and 95% CI 0.67 (0.58, 0.77), p<0.01; and 0.70 (0.55, 0.89), p<0.01, respectively.

CONCLUSIONS

Our results show that there is no significantly increased morbidity with ONB compared to IC. Selection of either urinary diversion technique should be based on factors such as tumor stage, comorbidities, surgical experience, and patient acceptance of postoperative sequalae.

Review of clinical experience on biomaterials and tissue engineering of urinary bladder

PURPOSE

In recent pre-clinical studies, biomaterials and bladder tissue engineering have shown promising outcomes when addressing the need for bladder tissue replacement. To date, multiple clinical experiences have been reported. Herein, we aim to review and summarize the reported clinical experience of biomaterial usage and tissue engineering of the urinary bladder.

METHODS

A systematic literature search was performed on Feb 2019 to identify clinical reports on biomaterials for urinary bladder replacement or augmentation and clinical experiences with bladder tissue engineering. We identified and reviewed human studies using biomaterials and tissue-engineered bladder as bladder substitutes or augmentation implants. The studies were then summarized for each respective procedure indication, technique, follow-up period, outcome, and important findings of the studies.

RESULTS

An extensive literature search identified 25 studies of case reports and case series with a cumulative clinical experience of 222 patients. Various biomaterials and tissue-engineered bladder were used, including plastic/polyethylene mold, preserved dog bladder, gelatine sponge, Japanese paper with Nobecutane, lypholized human dura, bovine pericardium, amniotic membrane, small intestinal mucosa, and bladder tissue engineering with autologous cell-seeded biodegradable scaffolds. However, overall clinical experiences including the outcomes and safety reports were not satisfactory enough to replace enterocystoplasty.

CONCLUSION

To date, several clinical experiences of biomaterials and tissue-engineered bladder have been reported; however, various studies have reported non-satisfactory outcomes. Further technological advancements and a better understanding is needed to advance bladder tissue engineering as a future promising management option for patients requiring bladder drainage.