BALTIMORE – While rates of surgical site infections after bariatric surgery have been reported in the low single digits, SSIs have continued to be a persistent complication.
At the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons, researchers reported on two strategies to reduce SSI in bariatric surgery: a predictive tool that identifies risk factors for wound infection, allowing surgeons to employ protective measures before and during surgery, and a change in surgical practice leading to a 78% reduction in wound infection rates that resulted from a single-center study.
Jerry Dang, MD, of the University of Alberta, Edmonton, reported that the BariWound predictive tool designed to stratify patients into risk categories showed a high level of accuracy with an area under the curve of 0.73. Cynthia Weber, MD, of University Hospitals, Cleveland, reported that changing the method for performing circular-stapled gastrojejunostomy (GJ) from the transoral to the transabdominal approach along with more vigilant use of wound protection reduced wound infection rates from 6% to 1.3%.
Dr. Dang noted that SSI has been reported as the most common hospital-acquired complication in bariatric surgery, with reported rates of between 1% and 10%. A 2014 analysis of the American College of Surgeons National Surgical Quality Improvement Program database reported an SSI rate of 1.8% (Surg Endosc. 2014;28:3285-92). Although these rates are low, Dr. Dang explained that his group wanted to identify factors associated with SSI within 30 days of bariatric surgery. They analyzed outcomes data of 274,187 patients in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database who had bariatric surgery in 2015 and 2016 (196,608 by laparoscopic sleeve gastrectomy [SG] and 77,579 laparoscopic Roux-en-Y gastric bypass [RYGB]). Their analysis determined an incisional SSI rate of 0.47% (n = 1,291). “Incisional SSI rates were four times higher for laparoscopic RYGB: 1.04% vs. 0.25%,” Dr. Dang said.
On multivariable logistic regression, the adjusted odds ratio of SSI after RYGB vs. SG was 3.13 (P less than .001). Other significant risk factors were chronic steroid or immunosuppressant use (odds ratio, 1.75; P = .001), female sex (OR, 1.48; P less than .001) and history of gastroesophageal reflux disease (OR, 1.45; P less than .001). Other factors with a 21%-31% greater risk of SSI were white race (P = .002), history of diabetes (P less than .001), hypertension (P less than .001), obstructive sleep apnea (P = .001), and longer operation times (P less than .001). Each single-digit increase in body mass index increased risk by 3%, and older age actually had a protective effect for unknown reasons, Dr. Dang noted.
The BariWound tool assigns points to each risk factor. Each hour of operation time and each 10 kg/m2 of weight carry a value of 1 point, with partial points allowed. RYGB equals 5 points, and chronic steroid/immunosuppressant use, 4 points. The tool assigns risk to four categories based on score and 30-day SSI rate:
- Low, less than 15 (1% risk of SSI).
- Moderate, 15-21.9 (1%-5%).
- High, 22-26.9 (5%-10%).
- Very high, greater than 27 (greater than 10%).