Effects of restorative proctocolectomy on renal and adrenal function

Sodium depletion and secondary hyperaldosteronism in outpatients with an ileostomy: a cross-sectional study

OBJECTIVE

Patients with an ileostomy may experience postoperative electrolyte derangement and dehydration but are presumed to stabilise thereafter. We aimed to investigate the prevalence of sodium depletion in stable outpatients with an ileostomy and applied established methods to estimate their fluid status.

METHODS

We invited 178 patients with an ileostomy through a region-wide Quality-of-Life-survey to undergo outpatient evaluation of their sodium and fluid status. The patients delivered urine and blood samples, had bioelectrical impedance analysis performed and answered a questionnaire regarding dietary habits.

RESULTS

Out of 178 invitees, 49 patients with an ileostomy were included; 22 patients (45%, 95% CI, 31-59%) had unmeasurably low urinary sodium excretion (<20 mmol/L), indicative of chronic sodium depletion, and 26% (95% CI, 16-41%) had plasma aldosterone levels above the reference value. Patients with unmeasurably low urinary sodium excretion had low estimated glomerular filtration rates (median 76, IQR 63-89, mL/min/1.73m2) and low venous blood plasma CO2 (median 24, IQR 21-26, mmol/L), indicative of chronic renal impairment and metabolic acidosis. Bioelectrical impedance analysis, plasma osmolality, creatinine and sodium values were not informative in determining sodium status in this population.

CONCLUSION

A high proportion of patients with an ileostomy may be chronically sodium depleted, indicated by absent urinary sodium excretion, secondary hyperaldosteronism and chronic renal impairment, despite normal standard biochemical tests. Sodium depletion may adversely affect longstanding renal function. Future studies should investigate methods to estimate and monitor fluid status and aim to develop treatments to improve sodium depletion and dehydration in patients with an ileostomy.IMPACT AND PRACTICE RELEVANCE STATEMENTSodium depletion in otherwise healthy persons with an ileostomy was identified in a few publications from the 1980s. The magnitude of the problem has not been demonstrated before. The present study quantifies the degree of sodium depletion and secondary hyperaldosteronism in this group, and the results may help guide clinicians to optimise treatment. Sodium depletion is easily assessed with a urine sample, and sequelae may possibly be avoided if sodium depletion is detected early and treated. This could ultimately help increase the quality of life in patients with an ileostomy.

Ileostomy diarrhea: Pathophysiology and management

Ileostomy is a common component of surgical treatments for various gastrointestinal conditions. Loss of the fluid absorptive capacity of the colon results in increased fluid and electrolyte losses, which causes a state of relative fluid depletion. These losses can be offset in part by increased oral intake, but the remaining small intestine also compensates by increasing the efficiency of fluid and electrolyte absorption, a process termed adaptation, which occurs within weeks to months of ileostomy creation. Some patients fail to adapt adequately and have high ileostomy outputs from the time of surgery. Others with a previously well-adapted ileostomy may encounter periods of sustained high output when some additional process causes diarrhea. Many patients experience periods of high output after ileostomy creation and often require hospital readmission for this reason. Any patient with an ileostomy is at great risk of dehydration and electrolyte depletion should output rise dramatically. Prompt attention should be given to rehydration and identification of the underlying cause so that directed therapies may be implemented. This review discusses the alteration of normal intestinal fluid balance from colectomy with ileostomy, proposed mechanisms for adaptation, the differential diagnosis of ileostomy diarrhea, the evaluation of ileostomy diarrhea, and current treatment options.

Oral rehydration solution normalizes plasma renin and aldosterone levels in patients with ulcerative colitis after proctocolectomy

Objectives: The possible effects and benefits of oral rehydration solution (ORS) on chronic dehydration after total proctocolectomy. Methods: To evaluate the effect of ORS on the renin-angiotensin system after remnant proctocolectomy in patients with ulcerative colitis (UC), we selected 20 patients after remnant proctocolectomy, ileal J pouch-anal anastomosis, and construction of a diverting ileostomy for UC. Patients were randomly divided into two groups, A (n=9) or B (n=11), 2 weeks after the surgery. In group A, ORS (1000 mL/day) was given for the first 7 days and mineral water (1000 mL/day) for the next 7 days. In group B, mineral water (1000 mL/day) was given for the first 7 days and ORS (1000 mL/day) for next 7 days. Plasma levels of renin, aldosterone and excretion of sodium in urine were evaluated at days 0, 7, and 14. We defined day 0 as the day of beginning this study. Results: Mean plasma renin levels on day 0 were six to eight times greater than the upper normal limit. In group A, ORS lowered plasma renin levels. In group B, plasma levels of renin and aldosterone after ORS were lower than those at days 0 and 7. Conclusions: ORS corrected increased plasma levels of renin and aldosterone to within the normal range in patients after proctocolectomy.

Readmission for dehydration or renal failure after ileostomy creation

BACKGROUND

Ileostomy creation is a commonly performed operation in colorectal surgery; however, many patients develop complications such as dehydration postoperatively. Dehydration is often severe enough to warrant hospital readmission and may result in renal failure. The true incidence of this complication has not been well described.

OBJECTIVE

The aim of this study was to identify the rate of hospital readmission secondary to dehydration or renal failure within 30 days of ileostomy creation.

DESIGN

Retrospective review of all patients undergoing ileostomy creation from 2007 to 2011 in a single colorectal practice of 4 surgeons was performed. Charts were reviewed to identify patients readmitted for dehydration or renal failure within 30 days of operation. Data were then analyzed to identify predictors of readmission, dehydration, and renal failure. Subset analysis compared patients readmitted with simple dehydration versus patients with renal failure.

PATIENTS

Two hundred one patients undergoing colorectal operations that included ileostomy creation within a 4-year period at a single institution for a variety of indications were included.

MAIN OUTCOME MEASURES

The primary outcome measured was readmission for dehydration or renal failure.

RESULTS

We observed a 17% 30-day readmission rate for dehydration or renal failure following ileostomy creation. Age greater than 50 was identified as an independent predictor of readmission with renal failure, whereas IPAA was predictive of readmission for simple dehydration, but not renal failure. Patients admitted with renal failure had significantly longer hospital stays and median hospital charges after readmission in comparison with patients admitted with simple dehydration.

LIMITATIONS

This study was limited by its retrospective nature and its limited sample size.

CONCLUSION

Hospital readmission due to dehydration or renal failure following ileostomy creation is common, with age >50 being the strongest predictor for renal failure. Appropriate strategies to decrease dehydration and renal failure following ileostomy creation need to be investigated.

Risk factors for nephrolithiasis in patients with ileal pouches

BACKGROUND AND AIMS

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become a standard of care in patients with ulcerative colitis (UC). Nephrolithiasis is common in patients with inflammatory bowel disease (IBD), but has never been studied as a complication of IPAA. We aimed to assess the risk factors for nephrolithiasis in patients with IPAA.

METHODS

Using an IRB-approved, prospectively maintained pouch registry, we identified 1221 patients between 2000 and 2010. Those with post-IPAA nephrolithiasis served as the study group whereas IPAA patients without nephrolithiasis served as the controls. Demographic and clinical variables were analyzed using multivariable logistic regression to identify risk factors.

RESULTS

There were a total of 218 IPAA patients: 81 with nephrolithiasis (37%) and 137 without (63%). Of the 81 patients in the study group, 17 were excluded due to limited clinical data. Three risk factors were found to be associated with nephrolithiasis: the presence of extra-intestinal manifestations (odd's ratio [OR]=2.9, 95% confidence interval [CI]: 1.4, 5.8, p=0.003), no use of antibiotics (OR=3.2, 95% CI: 1.5, 6.5, p=0.002) and low serum bicarbonate level (OR=0.87, 95% CI: 0.77, 0.99, p=0.038).

CONCLUSION

Nephrolithiasis was a common finding in our patients with IPAA. As pouch patients with nephrolithiasis can develop adverse clinical complications, those with at least one of the risk factors we identified may need to be monitored more closely and possibly receive prophylactic treatment with oral bicarbonate.

Proctocolectomy-ileal pouch-anal anastomosis for ulcerative colitis after liver transplantation for primary sclerosing cholangitis: a multi-institutional analysis

BACKGROUND

The association between primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) often mandates their contemporaneous management. Orthotopic liver transplantation (OLTX) has emerged as the only curative therapy for PSC, and total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the definitive treatment for refractory UC. The published experience to date describing IPAA after OLTX has been limited; we sought to examine outcomes associated with proctocolectomy-IPAA after OLTX.

MATERIALS AND METHODS

We reviewed our multi-institutional experience performing proctocolectomy-IPAA for UC after OLTX for PSC.

RESULTS

Twenty-two patients underwent proctocolectomy-IPAA for UC after OLTX for PSC at four academic medical centers between 1989 and 2006. No perioperative complications or allograft dysfunction were observed. During a median follow-up of 52 months, complications have included transient dehydration (n = 6), chronic pouchitis (n = 2), recurrent PSC (n = 2), small bowel obstruction (n = 2), and pouch-anal anastomotic stricture (n = 1). Median 24-h stool frequency was 5, and fecal continence was reported as satisfactory by all patients.

CONCLUSIONS

This multi-institutional experience suggests that proctocolectomy-IPAA can be performed safely after OLTX. Management strategies should include optimization of small bowel length during pouch and ileostomy construction, vigorous postoperative hydration, early ileostomy closure, and careful monitoring for pouchitis.

A new drug delivery system targeting ileal epithelial cells induced electrogenic sodium absorption: possible promotion of intestinal adaptation

We previously demonstrated the induction of the epithelial sodium channel, prostasin, and 11beta-hydroxysteroid dehydrogenase type 2 and activation of sodium transport mediated by those molecules in the remnant ileum after total proctocolectomy. The aims of the present study were to develop a new drug delivery system that targets ileal epithelial cells and to enhance local mineralocorticoid action without systemic effects. Orally administered D-aldosterone-containing D,L-lactide/glycolide acid copolymer microspheres are absorbed in the rat terminal ileum and released aldosterone. Blood and terminal ileal tissues were collected 2 weeks after the administration of the microspheres, and the aldosterone concentrations, mRNA, and protein expressions of the above molecules and sodium transport were evaluated. Significantly high levels of tissue aldosterone in the absence of elevated plasma levels were detected in the microspheres-treated rats. Epithelial mRNA and protein expression of the above molecules increased significantly in the microspheres-treated animals. Electrogenic sodium transport in the ileum was enhanced in the microspheres-treated rats. Aldosterone-containing microspheres successfully induced the expression of the above molecules and activated sodium transport in the ileal mucosa, both of which are essential for intestinal adaptation. Pre- and/or postoperative treatment with this drug may compensate for the excessive loss of sodium and water following proctocolectomy.

An approach to analyze mechanisms of intestinal adaptation following total proctocolectomy

We hypothesized that epithelial cells of the remnant small intestine display "colonic" phenotype after total proctocolectomy. The aims of the present study were to identify preferentially expressed molecules in the colon or in the small intestine and to evaluate mRNA levels of those in the ileal pouch. Differential gene expression was investigated between the small intestine and the colon by using cDNA microarray and was confirmed by Northern blotting. Expression of three colonic mRNAs (3-hydroxy-3-methylglutaryl-coenzyme A synthase 2, deleted malignant brain tumors 1, carcinoembryonic antigen-related cell adhesion molecule 1) and one "small intestinal" (microsomal triglyceride transfer protein) mRNA were compared between the control and the ileal pouch mucosae by quantitative reverse transcriptase-polymerase chain reaction. Seventy-four clones were differentially expressed with more than a threefold difference. Differential expression was confirmed in all mRNAs examined, including 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 and microsomal triglyceride transfer protein. The mucosal expression of carcinoembryonic antigen-related cell adhesion molecule 1 mRNA in the ileal pouch was enhanced in humans. The remnant ileum develops some, but not all, colonic phenotype after total proctocolectomy. Comparative study of epithelial gene expression between the small intestine and the colon enables us to analyze mechanisms of intestinal adaptation after total proctocolectomy.

Aldosterone enhances 11beta-hydroxysteroid dehydrogenase type 2 expression in colonic epithelial cells in vivo

OBJECTIVE

[corrected] 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) metabolizes glucocorticoids, thus enabling aldosterone to bind to the mineralocorticoid receptor. However, little is known about the regulatory mechanism of epithelial 11beta-HSD2 expression in the gut.

MATERIALS AND METHODS

Sprague-Dawley rats were maintained on a sodium-depleted diet or subjected to continuous aldosterone infusion for 4 weeks. Plasma aldosterone and arginine-vasopressin (AVP) levels were measured by radioimmunoassay. Expression of 11beta-HSD2 in colonic epithelia was evaluated by Northern blotting and immunohistochemistry. T84 and Caco2 cells were stimulated with aldosterone, dexamethasone and AVP alone or in combination, and 11beta-HSD2 mRNA was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Sodium-depleted and aldosterone-infused rats showed an increase of plasma aldosterone and AVP. Both treatments resulted in induction of 11beta-HSD2 in the colonic epithelia at mRNA and protein levels. Positive immunoreactivity was detected in the cytoplasm of the surface epithelia in control rats. In contrast, epithelial cells in the crypt also showed immunoreactivity for 11beta-HSD2 in the proximal colon of dietary sodium-depleted and aldosterone-infused rats. Induction of 11beta-HSD2 mRNA was observed when T84 cells were stimulated with corticosteroids plus AVP.

CONCLUSIONS

Aldosterone has a pivotal role by increasing expression of 11beta-HSD2 in epithelial cells of the colon. AVP may act as a synergistic hormone in aldosterone-mediated 11beta-HSD2 induction.

Comparative study of epithelial gene expression in the small intestine among total proctocolectomized, dietary sodium-depleted, and aldosterone-infused rats

We previously demonstrated enhanced plasma aldosterone, ileal activation of epithelial sodium channel (ENaC), and induction of 11 beta-hydroxysteroid dehydrogenase type 2 after total proctocolectomies in rats. However, factors other than circulating aldosterone may cause molecular induction associated with sodium transport. Sprague-Dawley rats were treated with sodium-deficient diets or subcutaneous aldosterone infusion for 4 weeks. Rats also underwent total proctocolectomies as positive control. We extracted epithelial RNA from the distal small intestine and compared mRNA expression of the alpha, beta, and gamma subunits of ENaC, prostasin, sodium glucose transporter 1 (SGLT1), and the alpha1 and beta1 subunits of Na(+)/K(+)-ATPase among control, total proctocolectomized, dietary sodium-depleted, and aldosterone-infused rats by quantitative reverse transcription-polymerase chain reaction or Northern blotting. A significant increase in aldosterone was noted in sodium-depleted and aldosterone-infused rats. The induction of three subunits of ENaC and prostasin mRNA was observed in proctocolectomized, aldosterone-infused rats but not in dietary sodium-depleted rats. The levels of the alpha1 and beta1 subunits of Na(+)/K(+)-ATPase were similar among the experimental groups. SGLT1 mRNA was induced only in proctocolectomized rats. The molecular induction of ENaC, prostasin, and SGLT1 is unique for total proctocolectomized rats. Aldosterone infusion can induce several essential molecules for sodium absorption, as seen in total proctocolectomy.

Induction of 11beta-hydroxysteroid dehydrogenase type 2 and hyperaldosteronism are essential for enhanced sodium absorption after total colectomy in rats

BACKGROUND

Patients who undergo total colectomy with ileopouch anal reconstruction often have persistent diarrhea and frequent bowel movements. Analysis of the intestinal adaptation after total colectomy may lead to developing novel therapies for postoperative diarrhea.

METHODS

Sprague-Dawley rats underwent total colectomy with ileoanal reconstruction and were sacrificed 4 and 8 weeks later. Mucosal response to aldosterone was evaluated with the use of ileal mucosa in an Ussing chamber by measuring short circuit current after in vitro stimulation with aldosterone. We investigated the expression of 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD 2) in intestinal epithelial cells. To examine the role of hyperaldosteronism, we also evaluated rats treated with a sodium-deficient diet or subcutaneous aldosterone infusion.

RESULTS

Aldosterone levels increased 80-fold after total colectomy. A comparable amount of aldosterone dramatically increased aldosterone-mediated, amiloride-sensitive short circuit current in the mucosa from colectomized rats, but not in control rats. We measured an increase in 11beta-HSD 2 messenger RNA and protein in the distal ileum from colectomized rats. Circulating aldosterone appears to be essential for these functional and molecular changes because similar results were obtained by using the mucosa from both dietary sodium-depleted and aldosterone-infused rats.

CONCLUSIONS

Induction of 11beta-HSD 2 is essential for enhanced mineralocorticoid action in the remnant ileum after total colectomy in rats.