The American Journal of (2016) 212, 527-536

Review Adhesive small after laparoscopic and open colorectal surgery: a systematic review and meta-analysis

Gi Won Ha, M.D., Min Ro Lee, M.D., Ph.D.*, Jong Hun Kim, M.D., Ph.D.

Research Institute of Clinical Medicine, Chonbuk National University Medical School, San 2-20 Geumam-dong, Deokjin-gu, Jeonju, Jeonbuk 561-180, South Korea

KEYWORDS: Abstract Colorectal surgery; BACKGROUND: It is considered that laparoscopic surgery is associated with a much lower rate of ; postoperative formation of adhesions than open surgery. This meta-analysis assessed the incidence Adhesion; of adhesion-related readmissions and surgery for adhesive small bowel obstruction (SBO) in patients ; who underwent laparoscopic or open colorectal surgery. Small bowel METHODS: Multiple comprehensive databases were searched systematically to identify relevant obstruction studies and meta-analysis was done. RESULTS: Meta-analysis showed that laparoscopic surgery was associated with a lower rate of adhesive SBO, both for randomized clinical trials (relative risk [RR] .26, 95% confidence interval [CI] .10 to .67, I2541%) and nonrandomized studies (RR .49, 95% CI .32 to .76, I2591%). Laparo- scopic surgery was also associated with a lower rate of subsequent surgery for adhesive SBO, both for randomized clinical trials (RR .25, 95% CI .06 to .96, I250%) and nonrandomized studies (RR .56, 95% CI .33 to .94, I2577%). CONCLUSIONS: Laparoscopic colorectal surgery significantly reduced the rates of adhesive SBO and subsequent surgery for adhesive SBO, compared with open surgery. Ó 2016 Published by Elsevier Inc.

Small bowel obstruction (SBO) is defined as abdominal the abdominal cavity that are normally separated, are the pain or distension, vomiting, and the appearance of a most common complications of abdominal and pelvic dilated small bowel loop on abdominal radiography or surgery. About 65% to 75% of acute intestinal obstructions computed tomography. Postoperative adhesions, defined as are caused by adhesions, predominantly involving the small abnormal fibrous bands between organs and/or tissues in bowel.1 Of all types of , open colorectal surgery was found to result in the highest rate of adhesion-related There were no relevant financial relationships or any sources of support readmissions. Colorectal are associated with in the form of grants, equipment, or drugs. approximately 30% risk of adhesion-related complications The authors declare no conflicts of interest. over 4 years. Moreover, approximately 10% of the patients 1 1 * Corresponding author. Tel: 82-63-250-1570; fax: 82-63-271- who undergo colorectal surgery are at risk for readmission 6197. 2–4 E-mail address: [email protected] directly related to adhesions. Theoretically, laparoscopic Manuscript received November 29, 2015; revised manuscript February surgery is associated with a much lower rate of postoperative 13, 2016 formation of adhesions than open surgery. Because adhesion

0002-9610/$ - see front matter Ó 2016 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.amjsurg.2016.02.019 528 The American Journal of Surgery, Vol 212, No 3, September 2016 formation represents a stepwise failure of peritoneal tissue resolved by discussion between the reviewers. All studies repair mechanisms, clean dissection, and/or minimal blood investigating adhesive SBO in patients who underwent loss and/or less-environmental exposure of the bowel during laparoscopic and open surgery for were laparoscopic surgery may reduce the rate of adhesion considered. Studies included in the meta-analysis were formation. those in which most of the included patients had been However, it remains unclear whether laparoscopic diagnosed with malignant or benign tumors, and in which colorectal resection reduces rates of adhesion formation laparoscopic and open surgery were compared. Studies and the incidence of adhesive SBO when compared were excluded if they (1) mainly assessed patients with with open colorectal surgery. Several recent studies have inflammatory bowel disease such as ulcerative ; (2) reported lower rates of adhesive SBO after laparoscopic assessed only specific groups of patients, including elderly than after open colorectal surgery,5–12 whereas other studies or obese patients; (3) assessed patients who developed have reported comparable rates for the 2 approaches.13–16 adhesive SBO during the early postoperative period These access-related complications have been associated (,1 month follow-up); (4) had no extractable data and with increased morbidity and mortality rates, as well as the authors could not be reached to provide additional increased medical costs, because of rehospitalization and information; (5) were case series with fewer than 10 additional surgical procedures.17–20 The magnitude of patients; and (6) were not published in English. health problems and costs related to adhesions indicate the need to develop methods that reduce the occurrence Data extraction of postoperative adhesions. This meta-analysis was designed to assess the incidence All eligible studies were reviewed, and all relevant data of adhesion-related readmissions and surgery for adhesive were extracted independently by 2 reviewers using a SBO in patients who underwent laparoscopic and open predefined data extraction form. Variables recorded colorectal surgery. included: (1) study information, including last name of the first author, year of publication, country, and number of Methods patients in each group; (2) demographic, clinical, and treatment characteristics of the patients; and (3) follow-up This meta-analysis was performed in a manner consis- time and outcome measures. Any disagreements unresolved tent with the recommendations of the Preferred Reporting by discussion were reviewed by a 3rd reviewer. The Items for Systematic Reviews and Meta-Analyses state- primary outcome measure was incidence of adhesive ment.21 Multiple comprehensive databases were searched SBO, and the secondary outcome measure was surgery for studies that compared rates of adhesive SBO in patients for adhesive SBO. who underwent laparoscopic and open surgery for colo- rectal cancers. The study protocol was based on Cochrane Assessment of methodological quality review methods.22 The methodological quality of randomized clinical trials Data source and literature source (RCTs) was assessed using the Cochrane Collaboration risk of bias tool.22 The methodological quality of nonrandomized Multiple comprehensive databases, including PubMed studies (NRSs) was assessed using the Newcastle-Ottawa (January 1, 1976 to June 24, 2015), EMBASE (January 1, Quality Scale, which allocates a maximum of 9 points to 1985 to June 24, 2015), and the Cochrane Central Register each study and in which a score of 6 or more indicated of Controlled Trials (January 1, 1987 to June 24, 2015), high quality.23 Any unresolved disagreements between were searched. There were no restrictions on the year of reviewers were resolved through consensus discussions or publication. Articles in all languages were sought, but only consultation with a 3rd reviewer. those published in English were included in this study. The search terms and combinations included: ‘‘colorectal sur- Statistical analysis gery’’, ‘‘colorectal cancer’’, laparoscopy, adhesion, ileus, ‘‘small bowel obstruction’’. After the initial electronic The meta-analysis determined relative risk (RR) for search, articles were manually searched to identify addi- dichotomous outcomes using the Mantel-Haenszel statisti- tional studies. Articles identified were assessed individually cal method. Pooled es