Anastomotic configuration and mucosal 5-aminosalicyclic acid (5-ASA) concentrations in patients with Crohn's disease: a GISC study. Gruppo Italiano per lo Studio del Colon e del Retto

Results of the Eighth Scientific Workshop of ECCO: Prevention and Treatment of Postoperative Recurrence in Patients With Crohn's Disease Undergoing an Ileocolonic Resection With Ileocolonic Anastomosis

Despite the introduction of biological therapies, an ileocolonic resection is often required in patients with Crohn's disease [CD]. Unfortunately, surgery is not curative, as many patients will develop postoperative recurrence [POR], eventually leading to further bowel damage and a decreased quality of life. The 8th Scientific Workshop of ECCO reviewed the available scientific data on both prevention and treatment of POR in patients with CD undergoing an ileocolonic resection, dealing with conventional and biological therapies, as well as non-medical interventions, including endoscopic and surgical approaches in case of POR. Based on the available data, an algorithm for the postoperative management in daily clinical practice was developed.

Stapled side-to-side anastomosis might be better than handsewn end-to-end anastomosis in ileocolic resection for Crohn's disease: a meta-analysis

BACKGROUND

Ileocolic anastomosis is an essential step in the treatment to restore continuity of the gastrointestinal tract following ileocolic resection in patients with Crohn's disease (CD). However, the association between anastomotic type and surgical outcome is controversial.

AIMS

The aim of this meta-analysis is to compare surgical outcomes between stapled side-to-side anastomosis (SSSA) and handsewn end-to-end anastomosis (HEEA) after ileocolic resection in patients with CD.

METHODS

Studies comparing SSSA with HEEA after ileocolic resection in patients with CD were identified in PubMed and EMBASE. Outcomes such as complication, recurrence, and re-operation were evaluated. Eight studies (three randomized controlled trials, one prospective non-randomized trial, and four non-randomized retrospective trials) comparing SSSA (396 cases) and HEEA (425 cases) were included.

RESULTS

As compared with HEEA, SSSA was superior in terms of overall postoperative complications [odds ratio (OR), 0.54; 95 % confidence interval (CI) 0.32-0.93], anastomotic leak (OR 0.45; 95 % CI 0.20-1.00), recurrence (OR 0.20; 95 % CI 0.07-0.55), and re-operation for recurrence (OR 0.18; 95 % CI 0.07-0.45). Postoperative hospital stay, mortality, and complications other than anastomotic leak were comparable.

CONCLUSION

Based on the results of our meta-analysis, SSSA would appear to be the preferred procedure after ileocolic resection for CD, with reduced overall postoperative complications, especially anastomotic leak, and a decreased recurrence and re-operation rate.

A meta-analysis comparing conventional end-to-end anastomosis vs. other anastomotic configurations after resection in Crohn's disease

PURPOSE

This study compared outcomes between end-to-end anastomosis and other anastomotic configurations after intestinal resection for patients with Crohn's disease by using meta-analytical techniques.

METHODS

Comparative studies published between 1992 and 2005 of end-to-end anastomosis vs. other anastomotic configurations were included. Using a random effects model, end points evaluated were short-term complications and perianastomotic recurrence of Crohn's disease. Heterogeneity was assessed and sensitivity analysis was performed to account for bias in patient selection.

RESULTS

Eight studies (2 prospective, randomized, controlled trials; 1 nonrandomized, prospective; 5 nonrandomized, retrospective studies) reported on 661 patients who underwent 712 anastomoses, of which 383 (53.8 percent) were sutured end-to-end anastomosis and 329 (46.2 percent) were other anastomotic configurations (259 stapled side-to-side, 59 end-to-side or side-to-end, 11 stapled circular end-to-end). Anastomotic leak rate was significantly reduced in the other anastomotic configurations group (odds ratio (OR), 4.37; P = 0.02) and remained significantly lower in studies comparing only side-to-side anastomosis vs. end-to-end anastomosis (OR, 4.37; P = 0.02) and studies including only ileocolonic anastomosis (OR, 3.8; P = 0.05). Overall postoperative complications (OR, 2.64; P < 0.001), complications other than anastomotic leak (OR, 1.89; P = 0.04), and postoperative hospital stay (weighted mean difference, 2.81; P = 0.007) were significantly reduced in the side-to-side anastomosis group when considering studies comparing only side-to-side anastomosis vs. end-to-end anastomosis. There was no significant difference between the groups in perianastomotic recurrence and reoperation needed because of perianastomotic recurrence.

CONCLUSIONS

End-to-end anastomosis after resection for Crohn's disease may be associated with increased anastomotic leak rates. Side-to-side anastomosis may lead to fewer anastomotic leaks and overall postoperative complications, a shorter hospital stay, and a perianastomotic recurrence rate comparable to end-to-end anastomosis. Further randomized, controlled trials should be performed for confirmation.

Systematic review: the potential influence of mesalazine formulation on maintenance of remission in Crohn's disease

AIM

To evaluate the effectiveness of pH 6-/pH 7-dependent and controlled-release mesalazines in maintaining medically and surgically induced Crohn's disease remission.

METHODS

A systematic search identified 13 randomized controlled trials (RCTs). The rate of symptomatic relapse (Crohn's disease activity index >150, or an increase in baseline by at least 60-100 points) was extracted from each randomized controlled trial. Pooled odds ratios (OR), the number needed to treat (NNT), and percentage therapeutic benefit (absolute risk reduction) were calculated.

RESULTS

Treatment with pH 7-dependent mesalazine significantly reduced the risk of relapse in patients with either surgically [OR 0.28; 95% confidence interval (CI) 0.12-0.65; P = 0.0032] or medically induced remission (OR 0.38; 95% CI 0.17-0.85; P = 0.0113). However, treatment with controlled-release mesalazine and pH 6-dependent mesalazine failed to show any significant advantage over placebo. The NNT to maintain surgically or medically induced remission was lowest for pH 7-dependent mesalazine (NNT = 4 and 5, respectively; NNT = 15 and 16 for controlled-release mesalazine and NNT = 11 and 23 for pH 6-dependent mesalazine). Therapeutic benefit was highest for pH 7-dependent mesalazine (surgical = 30.6%, medical = 22.8%). This compared with 6.9% (surgical) and 6.4% (medical) for controlled-release mesalazine, and 9.8% and 4.4%, respectively, for pH 6-dependent mesalazine.

CONCLUSION

Further trials of pH 7-dependent mesalazine formulations are warranted in the maintenance of remission in Crohn's disease.

Indications for 5-aminosalicylate in inflammatory bowel disease: is the body of evidence complete?

Mesalazine is a safe drug, although adverse events may be seen in a minority of patients. This applies also to pregnant women and children. The role of mesalazine in combination therapy to improve efficacy and concomitant drug pharmacokinetics, or in chemoprevention against inflammatory bowel disease (IBD)-related colonic carcinoma has not yet been completely elucidated. Therapeutic success of mesalazine may be optimized by a combination of high dose and low frequency of dosage to improve compliance. Therefore, due to its superior safety profile and pharmacokinetic characteristics, mesalazine is preferable to sulphasalazine. This paper reviews the literature concerning mechanisms of action, indications and off-label use, pharmacokinetic properties and formulations, therapeutic efficacy, compliance, paediatric indications, chemoprevention, and safety issues and adverse event profile of mesalazine treatment versus sulphasalazine. It also highlights these controversies in order to clarify the potential benefits of mesalazines in IBD therapy and evidence for its use.

A novel anti-oxidant and anti-cancer strategy: a peptoid anti-inflammatory drug conjugate with SOD mimic activity

Activation of reactive oxygen and nitrogen species (RONS) by redox-active metal ions has been proposed to contribute to oxidative damage in inflamed tissues. Here, we report a dual-function anti-oxidant conjugate comprising an anti-inflammatory agent (5-aminosalicylic acid) and a chelator with potential as a superoxide dismutase mimic. The conjugate ethylenediaminetetraacetic acid bis-(5-aminosalicylic acid methyl ester) [EBAME] chelates Cu(II) ions in a 1:1 ratio, as assessed spectrophotometrically using Job's method. Superoxide dismutase (SOD) activity was determined for the Mn(II)-conjugate as 0.758+/-0.130 U at a concentration of 0.99 microM. In inflamed tissues, peptidase mediated release of active 5-ASA would also release the EDTA chelator which has significant SOD mimic activity when complexed to Cu(II) ions. Thus, EBAME has potential as a dual-function anti-inflammatory agent with reduced gastric irritability.

Azatioprina y mesalazina en la prevención de la recurrencia posquirúrgica en la enfermedad de Crohn: estudio retrospectivo

OBJECTIVES

Surgical resection is still a mainstay of the treatment of Crohn's disease (CD). However, recurrence is the rule. The aim of the present study was to evaluate CD recurrence in a series of patients who underwent surgical resection with subsequent treatment with azathioprine (AZA) or mesalazine (5-ASA) and to identify the factors associated with recurrence.

METHODS

The medical records of patients with CD who underwent bowel resection during a 4-year period were reviewed. Only patients who received AZA or 5-ASA as prophylaxis for recurrence were included.

RESULTS

Thirty-three patients treated with AZA and 16 treated with 5-ASA were included. Endoscopic recurrence was found in 8.6% of the AZA group and in 87.5% of the 5-ASA group (p <0.001). Clinical recurrence occurred in 31.2% of patients in the 5-ASA group and in none in the AZA group (p=0.004). The accumulated probability of both clinical and endoscopic recurrence was significantly lower in the AZA group (p=0.0025 and p=0.005, respectively). Factors associated with a greater risk of endoscopic recurrence were termino-terminal anastomosis and 5-ASA treatment. The only factor associated with clinical recurrence was 5-ASA treatment.

CONCLUSION

AZA seems to be more effective than 5-ASA in the prevention of postsurgical endoscopic recurrence of CD. Prospective studies with long-term follow-up are required to establish the true utility of AZA in the prophylaxis of CD recurrence.

Enteral Drug Absorption in Patients with Short Small Bowel

Drug therapy may become difficult when a significant amount of the small intestine is resected, as happens in patients with a short small bowel. Drug absorption from the gastrointestinal tract is altered in these patients; however, this effect is variable in patients and differs with each drug. Literature regarding clinical outcomes of normal or alternative administration routes in patients with a short small bowel is limited. We explored what is written about the normal absorption of commonly used drugs and what difference the resection of different but substantial parts of the small intestine makes. Changes in the gastrointestinal tract after resection of >50% of the small intestine causes malabsorption of macronutrients and micronutrients, and may alter the drug absorption process. The metabolic activity of the abundantly present intestinal lactobacilli can also affect the enteral drug absorption in patients with short small bowel as this results in the production of lactic acid, gaseous CO(2), ethanol and an increased bile acid deconjugation. Accelerated intestinal luminal transit time causes a reduction in absorption of certain antimicrobial agents, digoxin, hydrochlorothiazide, ciclosporin, cimetidine, mesalazine (5-aminosalicylic acid), oral contraceptives and levothyroxine. Gastric hypersecretion and lack of sufficient contact time with the intestinal mucosa in patients with short small bowel leads to insufficient absorption of drugs such as omeprazole. Successful treatment with warfarin, tricyclic antidepressants, metronidazole, fluconazole, procainamide, sotalol and pindolol are reported in several studies. Many different factors cause this variability in drug absorption in such patients. Monitoring the serum drug concentration in these patients may ease dealing with the management problems.

Pharmacokinetic considerations in the treatment of inflammatory bowel disease

This review describes the pharmacokinetics of the major drugs used for the treatment of inflammatory bowel disease. This information can be helpful for the selection of a particular agent and offers guidance for effective and well tolerated regimens. The corticosteroids have a short elimination half-life (t1/2beta) of 1.5 to 4 hours, but their biological half-lives are much longer (12 to 36 hours). Most are moderate or high clearance drugs that are hepatically eliminated, primarily by cytochrome P450 (CYP) 3A4-mediated metabolism. Prednisone and budesonide undergo presystemic elimination. Any disease state or comedication affecting CYP3A4 activity should be taken into account when prescribing corticosteroids. Depending on the preparation used, 10 to 50% of an oral or rectal dose of mesalazine is absorbed. Rapid acetylation in the intestinal wall and liver (t1/2beta 0.5 to 2 hours) and transport probably by P-glycoprotein affect mucosal concentrations of mesalazine, which apparently determine clinical response. Any clinical condition influencing the release and topical availability of mesalazine might modify its therapeutic potential. Metronidazole has high (approximately 90%) oral bioavailability, with hepatic elimination characterised by a t1/2beta of 6 to 10 hours and a total clearance of about 4 L/h/kg. Ciprofloxacin is largely excreted unchanged both renally (about 45% of dose) and extrarenally (25%), with a relatively short t1/2beta (3.5 to 7 hours). Thus, renal function affects the systemic availability of ciprofloxacin. Both mercaptopurine and its prodrug azathioprine are metabolised to active compounds (6-thioguanine nucleotides; 6-TGN) by hypoxanthine-guanine phosphoribosyltransferase and to inactive metabolites by the polymorphically expressed thiopurine S-methyltransferase (TPMT) and xanthine oxidase. Patients with low TPMT activity have a higher risk of developing haemopoietic toxicity. Both mercaptopurine and azathioprine have a short t1/2beta (1 to 2 hours), but the t1/2beta of 6-TGN ranges from 3 to 13 days. Therapeutic response seems to be related to 6-TGN concentration. Almost complete bioavailability has been observed after intramuscular and subcutaneous administration of methotrexate, which is predominantly (85%) excreted as unchanged drug with a t1/2beta of up to 50 hours. Thus, renal function is the major determinant for disposition of methotrexate. Cyclosporin is slowly and incompletely absorbed. It is extensively metabolised by CYP3A4/5 in the liver and intestine (median t1/2beta and clearance 7.9 hours and 0.46 L/h/kg, respectively), and inhibitors and inducers of CYP3A4 can modify response and toxicity. Infliximab is predominantly distributed to the vascular compartment and eliminated with a t1/2beta between 10 and 14 days. No accumulation was observed when it was administered at intervals of 4 or 8 weeks. Methotrexate may reduce the clearance of infliximab from serum.

Clinical pharmacology of inflammatory bowel disease therapies

Knowledge about the clinical pharmacology of medical therapy of inflammatory bowel disease has incrementally advanced. Small studies with mesalamine have suggested that intestinal mucosal concentrations of mesalamine may predict clinical response to mesalamine therapy. Increased expression of glucocorticoid receptor beta and increased expression of the multidrug resistance drug pump P-glycoprotein 170 have been proposed as markers of drug resistance to glucocorticoids. A baseline determination of thiopurine methyltransferase phenotype or genotype may predict early leukopenia in patients treated with azathioprine or 6- mercaptopurine. Serial measurement of erythrocyte 6-thioguanine nucleotides may be useful in tailoring the dose of these medications. A loading dose of intravenous azathioprine does not accelerate the time to response in patients with steroid-treated Crohn's disease; however, standard azathioprine may work more quickly than previously reported. Methotrexate, 15 to 25 mg/wk, is effective for the treatment of Crohn's disease (active or in remission), and there is no significant difference in the erythrocyte concentrations of methotrexate polyglutamate in patients with inflammatory bowel disease receiving 15 mg, compared with 25 mg, subcutaneously on a weekly basis.