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Professor of Obstetrics and Gynecology, Western Michigan University Homer Stryker M.D. School of Medicine, Kalamazoo
Dr. Rebar reports no financial relationships relevant to this field of study.
SYNOPSIS: The authors of a retrospective cohort study suggest that perioperative antibiotics reduce the risk of surgical site infection in women undergoing myomectomy.
SOURCE: Kim AJ, et al. Perioperative antibiotic use and associated infectious outcomes at the time of myomectomy. Obstet Gynecol 2019;133:626-635.
There has been a continuing effort to reduce the number and severity of surgical site infections, defined here as infection occurring within 30 days of surgery and involving the surgical incision(s), organ, or site. Part of that effort has involved the possible use of perioperative antibiotics. Current recommendations from the American College of Obstetricians and Gynecologists suggest the use of perioperative antibiotics in several gynecologic procedures, including laparotomy, but do not recommend use in cases involving diagnostic or operative laparoscopy not involving hysterectomy or a pre-existing infection.1
Although an estimated 34,000 myomectomies are performed annually in the United States,2 there are no good studies examining the use of perioperative antibiotics in these cases. Consequently, investigators at a single medical center in Boston sought to identify patterns of antibiotic use in a cohort of women undergoing myomectomy and to examine associations between antibiotic use and surgical site infections by reviewing data from women undergoing myomectomy at two area hospitals between the years of 2009 and 2016.
A total of 1,211 women undergoing myomectomy were included in the cohort. The most frequent indications for surgery were pelvic pain or pressure or heavy menstrual bleeding. Excluded from analysis were women undergoing vaginal or hysteroscopic myomectomy, those undergoing chromotubation, and those converted to hysterectomy. Almost 93% of the women received perioperative antibiotics, and only 88 women did not receive any antibiotics. Of those patients receiving perioperative antibiotics, 95.6% received a beta-lactam drug, most commonly cefazolin (1 to 3 g) intravenously. It was not possible to determine precisely when the antibiotics were administered. Two-thirds of the cases were performed in a minimally invasive manner, with almost 96% performed by trained subspecialists. Patients receiving antibiotics had longer median operative times (140 minutes vs. 85.5 minutes; P < 0.001), greater estimated blood loss (137.5 mL vs. 50 mL; P < 0.001), a greater number of myomas removed (7.2 vs. 2.4; P < 0.001), greater median myoma weight (255 g vs. 52.9 g; P < 0.001), higher frequency of entry into the endometrial cavity (30.1% vs. 13.6%; P = 0.001), and longer median length of stay (1 vs. 0 days; P < 0.001). Yet, multivariable regression analysis of infectious outcomes, which controlled for age, route of surgery, high-risk factors, any intraoperative complication, myoma weight, and entrance into the endometrial cavity, indicated that surgical site infection occurred almost four-fold more commonly in the absence of antibiotics (6.8% vs. 2.9%; adjusted odds ratio, 3.77; 95% confidence interval, 1.30-10.97; P = 0.015).
A retrospective cohort study from a single institution involving a limited number of surgeons, most with advanced fellowship training in minimally invasive surgery, is far from the ideal way to answer a clinical question. The authors themselves noted that they were unable to tabulate data regarding many perioperative factors that might contribute to surgical site infection, including any type of preoperative abdominal and vaginal wash, hair clipping, type of surgical scrub, method of wound closure, and intraoperative temperature. The authors further noted that the generalizability of their findings might be limited because most patients were white and largely healthy, with low rates of diabetes mellitus and active smoking and an average body mass index of less than 30 kg/m2.
So why choose this article? Surgical site infections are the second most common reason for unplanned hospital readmission after hysterectomy and result in increased morbidity and healthcare costs.3 Surgical site infections are a common cause of morbidity for all gynecologic procedures. Because of the frequency of infections following gynecologic surgery, various groups have attempted to develop consensus patient safety bundles to prevent infection.4,5 Investigators are reporting in the literature that adherence to such gynecologic-specific bundles is proving effective for hysterectomy. In one recent study, full implementation of a patient safety bundle reduced the site-specific infection rate for hysterectomy from 4.51% to 1.87%.6 Maintaining low rates will require continued vigilance and adherence to the entire patient safety bundle, including appropriate therapy for medical conditions such as diabetes prior to and during surgery, standardization of a patient wash before admission, preoperative and intraoperative warming, standardized aseptic skin and vaginal preparation, standardized regimens for sterile dressing, standardized antibiotic use, and timely and constructive direct feedback to all members of the healthcare team. In a study examining data from the National Surgical Quality Improvement Program, researchers reported that minimally invasive surgery was associated with reduced rates of surgical site infection for each of four procedures (appendectomy, colectomy, hysterectomy, and radical prostatectomy) examined.7
We have an obligation to attempt to reduce surgical site infection for all gynecologic procedures. Myomectomy is becoming more common as women delay childbearing. Kim et al emphasized the need for randomized, controlled trials to document that standardized antibiotic prophylaxis can reduce surgical site infection. We are all aware of circumstances in which randomized trials have failed to replicate findings from retrospective studies. In a review of guideline-based antibiotic prophylaxis for more than 545,000 women undergoing gynecologic surgery for whom antibiotic prophylaxis was recommended (abdominal, vaginal, or laparoscopically assisted vaginal hysterectomy), investigators indicated that 87.1% received appropriate prophylaxis, 2.3% received non-guideline recommended antibiotics, and 10.6% received no prophylaxis.8 Among more than 490,000 women who had surgery for which antibiotic prophylaxis was not recommended (oophorectomy, cystectomy, tubal ligation, dilation and curettage, and myomectomy), 40.2% received antibiotics.8 Yet, we all know that giving antibiotics in situations in which the benefit is unproven may have untoward consequences as well.
With regard to myomectomy, the authors of a Cochrane Review concluded that laparoscopic myomectomy is associated with less subjectively reported postoperative pain, lower postoperative fever, and shorter hospital stay compared with all types of open myomectomy.2 This meta-analysis was unable to address site specific infection, uterine rupture, occurrence rates for thromboembolism, and the need for repeat myomectomy and hysterectomy at a later date. Still, it suggests that minimally invasive surgery is indicated for myomectomy when and where possible. The study by Kim et al strongly suggested that perioperative antibiotics should be used for women undergoing myomectomy by whatever route until such time as we have the definitive answer from needed randomized trials. Accumulating literature further indicates the need for each medical center to develop standardized patient safety bundles for all gynecologic procedures to reduce surgical site infection. I selected this imperfect but informative article for discussion to emphasize this need. Moreover, for the present the article should encourage us all to use perioperative antibiotics when performing myomectomy.
Financial Disclosure: OB/GYN Clinical Alert’s Editor Jeffrey T. Jensen, MD, MPH, reports that he is a consultant for and receives grant/research support from ObstetRx, Bayer, Merck, and Sebela; he receives grant/research support from Abbvie, Mithra, and Daré Bioscience; and he is a consultant for CooperSurgical and the Population Council. Peer Reviewer Catherine Leclair, MD; Nurse Planners Marci Messerle Forbes, RN, FNP, and Andrea O’Donnell, FNP; Editorial Group Manager Leslie Coplin; Editor Jonathan Springston; and Accreditations Manager Amy M. Johnson, MSN, RN, CPN, report no financial relationships relevant to this field of study.