Infection risk after surgery in patients using medications for inflammatory bowel disease

Background

More than 1.2 million individuals in North America are affected by inflammatory bowel disease (IBD). It is a condition that involves inflammation in the large and/or small intestine(s), resulting in symptoms such as diarrhea and abdominal pain. Many of the medications used to treat IBD suppress the immune system. As a result, use of these medications increases the risk of infection. This increased risk of infection is particularly concerning in patients undergoing surgery.

Review Question

This systematic review examined the combined data from 68 previously published studies to determine whether patients using IBD medications around the time of surgery had more infections compared to those not using the same medications.

Study Characteristics

This systematic review is current up to 29 October 2019. It included 68 studies in patients with IBD who underwent surgery. Most participants were 18 years or older and both men and women were included. Five IBD medication groups were examined within our study. Infections were tracked up to 30 days after surgery.

Key Results

Analyses of this large set of data revealed that infection risk around the time of surgery varied depending on which type of IBD medication the patients were on. Patients being treated with corticosteroids or anti-TNF agents seemed to have more infections after surgery, while those on 5-ASA, immunomodulators or anti-integrin agents did not seem to have more infections after surgery. These findings should be taken with caution as our review included studies which were of limited quality, and therefore we were not able to draw any firm conclusions.

These findings could help doctors choose which medications to treat IBD patients with before surgery. Decisions should be tailored to each patient's unique health needs. In addition, this study suggests the need to carefully monitor for infections after surgery in patients who are on certain types of IBD medications.
 

Limitations

One limitation of this systematic review was its dependence on data from a wide range of previously published studies, with various approaches and quality control standards. Most studies examined had very low certainty regarding its conclusions. This review illustrates the need for future high-quality research examining the impact of medications used to treat IBD on infection risk after surgery.

Authors' conclusions: 

The evidence regarding corticosteroids, 5ASA, immunomodulators, anti-TNF mediations and anti-integrin medications was low or very low in certainty. Thus, the impact of these medications on postoperative infectious complications is uncertain and no firm conclusions can be drawn regarding their safety in the perioperative period. Decisions regarding preoperative IBD medications should be tailored to each patient’s unique circumstances. Future studies should focus on controlling for potential confounding factors to generate higher quality evidence.

Read the full abstract...
Background: 

Medications used to treat inflammatory bowel disease (IBD) have significantly improved patient outcomes and delayed time to surgery. However, some of these therapies are recognized to increase the general risk of infection and have an unclear impact on postoperative infection risk.

Objectives: 

To assess the impact of IBD medications on postoperative infection risk within 30 days of surgery.

Search strategy: 

We searched the Cochrane IBD Groups Specialized Register (29 October 2019), MEDLINE (January 1966 to October 2019), EMBASE (January 1985 to October 2019), the Cochrane Library, Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform from inception up to October 2019 and reference lists of articles.

Selection criteria: 

Randomized controlled trials, quasi-randomized controlled trials, non-randomized controlled trials, prospective cohort studies, retrospective cohort studies, case-control studies and cross-sectional studies comparing patients treated with an IBD medication preoperatively or within 30 days postoperatively to patients who were not taking that medication. Manuscripts and abstracts were included.

Data collection and analysis: 

Two authors independently screened titles and abstracts and extracted data. The primary outcome was postoperative infection within 30 days of surgery. Secondary outcomes included incisional infections and wound dehiscence, intra-abdominal infectious complications and extra-abdominal infections. Three authors assessed risk of bias using the Newcastle-Ottawa scale. We contacted authors for additional information when data were missing. For the primary and secondary outcomes, we calculated odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) using the generic inverse variance method. When applicable, we analyzed adjusted and unadjusted data separately. The certainty of the evidence was evaluated using GRADE.

Main results: 

Sixty-eight non-randomized studies were included. Twenty-four studies had low risk of bias while the remaining had very high risk. Based on pooling of adjusted data, overall infectious complications were increased in patients who received anti-TNF agents (OR 1.60; 95% CI 1.20 to 2.13; very low certainty evidence) and corticosteroids (OR 1.70; 95% CI 1.38 to 2.09; low certainty evidence). Use of 5-ASA (OR 0.76; 95% CI 0.51 to 1.14; very low certainty evidence), immunomodulators (OR 1.29; 95% CI 0.95 to 1.76; low certainty evidence) and anti-integrin agents (OR 1.04; 95% CI 0.79 to 1.36; low certainty evidence) had no impact on overall infectious complications. No difference in the odds of wound-related complications was seen in patients using corticosteroids, 5-ASA, immunomodulators, anti-TNF or anti-integrin agents when compared to controls. Both corticosteroids and anti-TNF agents increased odds of intra-abdominal infection (OR 1.53; 95% CI 1.28 to 1.84; very low certainty evidence and OR 1.38; 95% CI 1.04 to 1.82; very low certainty evidence, respectively) whereas no impact was observed with 5-ASA, immunomodulators or anti-integrin agents. The rate of extra-abdominal infections was not affected by corticosteroids, immunomodulators, anti-TNF or anti-integrin agents.