Significance of renal function in changes in acid-base metabolism after orthotopic bladder replacement: colon neobladder compared with ileal neobladder

Ileal conduit to small intestine fistula following extensive abdominopelvic resection and radiation for metastatic colon cancer

A woman in her mid-60s presented with decreased output from urostomy, which was an opening from the neobladder (ileal conduit). Presentation was preceded by a 6-month history of alternating faecaluria and increased colostomy output. Laboratory studies were notable for normal anion gap metabolic acidosis. Creatinine level of the colostomy output was 17.7 mg/dL, a finding indicative of the presence of urine in the sample. CT enterography and X-ray loopogram confirmed neobladder to small intestine fistula.Neobladder creation is commonly performed in patients with bladder cancer requiring resection. Fistulas between the neobladder and intestine are observed in fewer than 2.7% of cases. The patient's history of extensive abdominopelvic resection, colostomy creation and radiation likely contributed to fistula development. We highlight the need for a high index of suspicion for a fistula in a patient with a neobladder experiencing recurrent urinary tract infections or a high colostomy output concurrently with low neobladder output.

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.

Urinary Diversion and Metabolic Acidosis: A Case Report

Urinary diversion, a surgical technique to redirect urine usually after cystectomy, and its complications are potential challenges to physicians and early recognition decreases mortality and morbidity. A 45-year-old male with a history of type 2 diabetes mellitus and hypertension for over three years underwent urinary diversion as a treatment for invasive bladder cancer and was discharged ambulatory with an indwelling Foleys catheter. The patient returned to the emergency room with a primary complaint of hematuria. The patient was noted to be frail-looking, dehydrated and tachycardic. Laboratory results yielded an acute kidney injury reflected by the elevated creatinine, hyperkalemia and a venous blood gas demonstrating a hyperchloremic metabolic acidosis. The patient had bilateral distended renal calyces by ultrasound and irrigation of bladder through a three-way Foley showed to have large thick clots. The patient was admitted under the surgical intensive care unit after involving appropriate sub-specialties. The patient was started on sodium bicarbonate infusion, broad-spectrum antibiotics and a urinary catheter in place to monitor urine output. The patient's acidosis steadily improved with correction of his laboratory parameters, transferred out of ICU and the remaining stay in the medical ward was uneventful. The purpose of this case report is to help demonstrate the association between urinary diversion and the type of acidosis that subsequently develops in relation to this surgical procedure.

[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.

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.

Risk Factors for Developing Metabolic Acidosis after Radical Cystectomy and Ileal Neobladder

Purpose

To investigate the serial changes of metabolic acidosis and identify associated risk factors in patients who underwent radical cystectomy and ileal neobladder.

Material and Methods

From January 2010 to August 2014, 123 patients who underwent radical cystectomy and ileal neobladder reconstruction for bladder cancer were included in this study. Metabolic acidosis was defined as a serum bicarbonate level less than 22 mEq/L and impaired renal function was defined as a GFR <50ml/min. The presence of metabolic acidosis was evaluated at 1 month, 1 year, and 2 years after surgery. Multivariate logistic regression analysis was conducted to identify risk factors associated with development of metabolic acidosis.

Results

Metabolic acidosis was observed in 52%, 19.5%, and 7.3% of patients at 1 month, 1 year, and 2 years after surgery, respectively. At 1 month after surgery, impaired renal function was the only independent risk factor associated with metabolic acidosis (OR 3.87, P = 0.046). At 1 year after surgery, diabetes was the only independent risk factor associated with metabolic acidosis (OR 5.68, P = 0.002). At 2 years post-surgery, both age and diabetes were significant risk factors associated with metabolic acidosis.

Conclusion

Approximately, half of patients experienced metabolic acidosis one month after ileal neobladder reconstruction. Preoperative impaired renal function was the most significant risk factor for developing metabolic acidosis in the early postoperative period. However, the incidence of metabolic acidosis decreased to less than 20% 1 year after surgery, and diabetes was an independent risk factor during this period.

An unrecognised case of metabolic acidosis following neobladder augmentation cystoplasty

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Hyperchloraemic metabolic acidosis is a well established complication following urinary diversion.

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Patients with orthotopic neobladder with high residual urine and large capacity are at particular risks.

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A delay in the diagnosis can lead to significant morbidity.

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The risks of metabolic acidosis should be clearly documented on discharge to ensure early recognition by non-specialists.

Introduction

Presentation of case

Discussion

Conclusion

Risk factors of hospital readmission after radical cystectomy and urinary diversion: analysis of a large contemporary series

OBJECTIVES

To determine the incidence, risk factors and causes of hospital readmission in a large series of patients who underwent radical cystectomy (RC) and urinary diversion.

PATIENTS AND METHODS

We retrospectively analysed the data of 1000 patients who underwent RC and urinary diversion between January 2004 and September 2009 in our tertiary referral centre. Patients stayed in hospital for 21 and 11 days for orthotopic and ileal conduit diversions, respectively. The primary outcome was the development of a complication requiring hospital readmission at ≤3 months (early) and >3 months (late). Causes of hospital readmissions were categorised according to frequency of readmissions. Predictors were determined using univariate and multivariate logistic regression models.

RESULTS

In all, 895 patients were analysed excluding 105 patients because of perioperative mortality and loss to follow-up. Early and late readmissions occurred in 8.6% and 11% patients, respectively. The commonest causes of first readmission were upper urinary tract obstruction (UUO, 13%) and pyelonephritis (12.4%) followed by intestinal obstruction (11.9%) and metabolic acidosis (11.3%). The development of postoperative high-grade complications (odds ratio [OR] 1.955; 95% confidence interval [CI] 1.254-3.046; P = 0.003) and orthotopic bladder substitution (OR 1.585; 95% CI 1.095-2.295; P = 0.015) were independent predictors for overall hospital readmission after RC. Postoperative high-grade complications (OR 2.488; 95% CI 1.391-4.450; P = 0.002), orthotopic bladder substitution (OR 2.492; 95% CI 1.423-4.364; P = 0.001) and prolonged hospital stay (OR 1.964; 95% CI:1.166-3.308; P = 0.011) were independent predictors for early readmission while hypertension (OR 1.670; 95% CI 1.007-2.769; P = 0.047) was an independent predictor for late readmission.

CONCLUSION

Hospital readmissions are a significant problem after RC. In the present study, UUO, pyelonephritis, metabolic acidosis and intestinal obstruction were the main causes of readmission. Orthotopic bladder substitution and development of postoperative high-grade complications were significant predictors for overall readmission.

Neobladder long term follow-up

One of the commonest forms of orthotopic bladder substitution for bladder cancer survivors, used in our institute, is the use of ileocecal segment. Sometimes, the need for Indiana pouch heterotropic continent diversion arises.

AIM

To compare the long-term effect of orthotopic ileocecal bladder and heterotropic Indiana pouch following radical cystectomy in bladder cancer patients.

PATIENTS AND METHODS

Between January 2008 and December 2011, 91 patients underwent radical cystectomy/anterior pelvic exentration and orthotopic ileocecal bladder reconstruction (61 patients) and Indiana pouch (30 patients), when orthotopic diversion could not be technically or oncologically feasible.

RESULTS

Convalescence was uneventful in most patients. All minor and major urinary leakage cases, in both diversions groups, where successfully conservatively treated. Only one patient in the ileocecal group with major urinary leak required re-exploration with successful revision of uretro-colonic anastomosis. Only one patient in the Indiana pouch group had accidentally discovered sub-centimetric stone, which was simply expelled. The overall survival proportion of ileocecal group was 100% compared to 80% in the Indiana pouch group (p<0.001). The disease free survival proportion of ileocecal group was 90.8% compared to 80% in the Indiana pouch group (p=0.076). Effective comparative daytime and nighttime urinary continence as well as renal function deterioration were not statistically significant between both reconstruction types.

CONCLUSION

Both ileocecal bladder and Indiana pouch are safe procedures in regard to long-term effects over kidney function following radical cystectomy.

Morphological changes on the intestinal mucosa in orthotopic neobladder

INTRODUCTION

The intestinal mucosa undergoes significant atrophic changes when it is used to reconstruct the urinary tract. We analyzed the ultrastructural changes of intestinal mucosa in the orthotopic neobladder on the basis of our clinical experience.

PATIENTS AND METHODS

Fifteen male patients with an ileal neobladder underwent endoscopic biopsy at different postoperative intervals.

RESULTS

No significant changes were observed 3 months after surgery. After 6 and 12 months, the structure of the microvilli was modified significantly. No other substantial changes after 24 months were observed.

CONCLUSIONS

Progressive modifications occur in the cytoplasmic structures involved in the absorptive process. They do not seem to begin before 3 months and are almost totally completed after 1 year.

Orthotopic neobladder reconstruction after radical cystectomy in patients with a solitary functioning kidney: clinical outcome and evaluation

OBJECTIVE

To evaluate, in a prospective study, the clinical outcome of orthotopic neobladder reconstruction after radical cystectomy in patients with a solitary functioning kidney at the time of surgery.

PATIENTS AND METHODS

This study included a total of 28 patients (25 males and three females) with muscle invasive bladder cancer and a solitary functioning kidney at the time of surgery who underwent radical cystectomy (anterior pelvic excentration for females) and urinary reconstruction using orthotopic neobladder at The National Cancer Institute, Cairo University between February 2004 and April 2009. The surgical procedures included ileocaecal neobladder in 19 patients, ileal neobladder (Studer) in five and sigmoid neobladder in four. All perioperative and long-term complications were recorded. The renal functions were evaluated using mainly serum creatinine level, abdominal ultrasonography and intravenous urography (IVU).

RESULTS

The mean age of patients was 51.4years (range of 38-62years) while the mean follow-up period was 41.4months (range 18-62months). Early complications included wound infections in five patients, urine leakage in six, abdominal dehiscence with deep venous thrombosis in two, intestinal obstruction and prolonged ileus in three. During the follow-up period, 21 renal units (75%) remained stable with normal serum creatinine level and normal radiological configuration of the kidney. The remaining seven patients (25%) developed varying degrees of renal deterioration either due to uretero-intestinal stricture in three patients (10.7%), who were all treated by open surgical revision of the anastomotic sites or due to stricture at the vesico-urethral anastomosis in four patients (14.3%) that had been successfully managed by endoscopic dilatation and internal urethrotomy with stabilization of renal function. Severe metabolic acidosis occurred in one patient while mild forms occurred in three. These four patients required sodium bicarbonate therapy and their metabolic status was normalized thereafter.

CONCLUSION

Selecting the type of urinary diversion is important in patients with a solitary functioning kidney after radical cystectomy. Orthotopic neobladder reconstruction is a good choice in properly selected patients and could provide comparatively satisfactory results. Accordingly, a solitary functioning kidney should not be regarded as a contraindication for neobladder reconstruction after radical cystectomy.

Ileocystoplasty in rats: metabolic, renal and enteropatch changes in a mid- and long-term follow-up

INTRODUCTION

Bladder augmentation predisposes humans to many metabolic, renal and enteropatch changes. Our aim was to evaluate in a rat model of ileocystoplasty mid- and long-term urinary, metabolic, renal and graft changes.

MATERIALS AND METHODS

We performed an ileocystoplasty and a sham operation in 30 rats. Seven augmented rats and 3 sham-operated animals were euthanized after 1, 3 and 6 months. We performed urinalysis, urine culture and blood sampling for serum electrolytes and urea. Histopathological changes of the ileal patch and kidneys were also evaluated.

RESULTS

The urine cultures were positive in 14.3, 57 and 71%, respectively, 1, 3 and 6 months after surgery. Urinary pH, serum chloride and urea of the augmented group were significantly higher. Bladder calculi were formed in 23.8% of ileocystoplasty. Histopathological examination showed urothelialization of the graft with hyperplastic/metaplastic changes. The kidneys showed glomerular depletion and a marked distal tubular ectasia.

CONCLUSIONS

Our data showed that, in a mid- and long-term follow-up, rat bladders subjected to ileocystoplasty displayed hyperchloremic metabolic acidosis, electrolyte imbalance, enhanced serum blood urea levels and glomerular/tubular changes. Hyperplastic and/or metaplastic changes at the junctional zone were observed. Our experimental results suggest that frequent monitoring of renal function and surveillance of humans who have undergone ileocystoplasty are recommended.

Coronary spasm and hypersensitivity to amoxicillin: Kounis or not Kounis syndrome?

Several reports have suggested that the onset of allergic phenomena in predisposed subjects may trigger an angina episode, and this association has been described as Kounis syndrome. However, no previous reports have convincingly demonstrated a causal relationship between allergic reactions and acute coronary syndrome, and other possible mechanisms have not been excluded as causes of angina onset. We present a patient with chronic metabolic acidosis because of ureteroileourethrostomy and history of hypersensivity to beta-lactamic agents. He suffered three episodes of documented vasospastic angina, two of them related to amoxicillin administration; however, worsening of metabolic acidosis was found in all three episodes. This report shows that although allergic phenomena could play a role triggering this kind of acute coronary syndrome, other uncommon underlying mechanisms should be considered before the diagnosis of Kounis syndrome is established.

Clinical outcome of orthotopic neobladder replacement in patients with a solitary functioning kidney

OBJECTIVE

To evaluate the outcome of orthotopic neobladder creation in patients with a solitary functioning renal unit at the time of surgery.

METHODS

This study included a total of 18 patients (15 men and three women) with a solitary functioning kidney who underwent radical cystectomy for invasive bladder cancer followed by orthotopic neobladder replacement. Of these, an ileal, ileocolic or sigmoid colon neobladder was constructed in 11, three or four patients, respectively. Clinical data from these patients were retrospectively reviewed to clarify the significance of neobladder creation in patients with a solitary functioning kidney.

RESULTS

During the observation period of this series (mean, 44.2 months; range, 15-95 months), there were nine early complications in six patients (wound infection, ileus, urine leakage and pulmonary embolism in four, three, one and one, respectively) and 10 late complications in nine patients (severe metabolic acidosis, vesicourethral anastomotic stricture, ureterointestinal anastomotic stricture and neobladder calculi in six, two, one and one, respectively). Severe metabolic acidosis occurred in six (five ileal neobladders and one ileocolic neobladder); however, there were no significant differences in preoperative renal function and serum electrolytes as well as postoperative voiding function between patients with and without severe metabolic acidosis. These six patients required administration of sodium bicarbonate, and their metabolic status was normalized thereafter. Furthermore, there were no significant differences in renal function and serum electrolytes between these two groups throughout the observation period, and none of the patients demonstrated renal deterioration.

CONCLUSIONS

These findings suggest, despite the analysis including a small number of patients with a short follow-up period, orthotopic neobladder replacement could provide comparatively satisfactory results in patients with a solitary functioning kidney; hence, a solitary kidney should not be regarded as a contraindicated factor for neobladder creation after radical cystectomy.