Triological Society Best Practice
Are prophylactic antibiotics necessary for otologic surgery?†
The authors have no funding, financial relationships, or conflicts of interest to disclose.
Otologic surgery, performed for a variety of disorders such as chronic otitis media with or without tympanic membrane perforation, cholesteatoma, and otosclerosis can be classified as clean, clean-contaminated, or contaminated. Regardless of classification, these cases are generally associated with low rates of infection and high success rates. Perioperative antibiotics have been advocated to minimize infectious complications such as wound infection, purulent otorrhea, labyrinthitis, and tympanic membrane graft failures; however, their routine use for otologic surgery remains controversial. In this Triological Society Best Practice review, we examined the evidence regarding the use of prophylactic antibiotics in otologic surgery.
Several studies have compared the use of systemic antibiotics to placebo in otologic surgery (Table 1). In 1988, John et al.1 published a prospective, single-blind, randomized study of 130 patients who underwent myringoplasty. Patients in the antibiotic group received 250 mg of ampicillin and 250 mg of flucloxacillin 1 hour prior to surgery and orally four times a day for 5 days postoperatively. At 8 weeks postoperatively, there were no significant differences between the antibiotic and no-antibiotic groups in terms of tympanic membrane graft success (85% vs. 87%), air conduction, or bone conduction. Only one case of wound infection occurred (not stated whether this patient received antibiotics or not). The authors concluded that prophylactic antibiotics do not influence the rate of postoperative infection, graft success, or audiometric results.
Table I. Summary of Prospective Studies Evaluating the Role of Perioperative Antibiotics in Otologic Surgery
|John et al. (1988)||130||N/A||N/A||87||85|
|Govaerts et al. (1998)||750||4.7||3.1||99.7||99.5|
|Hester et al. (1998)||146||5.3||1.4||90.7||93|
|Tong et al. (2002)||101||N/A||N/A||89||82–85|
Also in 1988, Jackson2 published a large prospective, double-blind, randomized, placebo-controlled study of 3,481 patients who underwent otologic and neurotologic surgery over a 7-year period. Most cases were classified as clean (89.1%), whereas the rest were contaminated infected ears (10.9%). In the antibiotic group, intravenous cefazolin or oxacillin was given prior to incision and continued every 6 hours for 24 hours after surgery. At 3 weeks postoperatively, the wound infection rates were similar: 5.7% in the placebo group and 6.0% in the antibiotic group. In patients with preoperative infections, antibiotics favorably influenced postoperative wound infection rates (3.8% vs. 6.5%, with and without antibiotics, respectively), but the differences were not significant. In terms of tympanic membrane grafting, the success rates were again similar: 98.8% in the placebo group and 98.5% in the antibiotic group. The authors concluded that antibiotics do not reduce postoperative infection or tympanic membrane graft success, challenging the common practice of giving antibiotic prophylaxis.
Ten years later in 1998, Govaerts et al.3 published a prospective, double-blind, randomized, placebo-controlled study of 750 patients who underwent either clean or contaminated procedures from January 1993 to June 1995. In the group randomized to antibiotics, intravenous cefuroxime was given both prior to incision and 6 hours later. Within the first postoperative week, there was noted to be a significantly higher rate of wound infection in the patients receiving placebo. At 2 weeks postoperatively, however, the wound infection rates became similar in the placebo group and the antibiotic group (4.7% and 3.1%, respectively). In clean ears, the postoperative infection rate was especially low (<5%), and thus the authors concluded that antibiotic prophylaxis was not indicated for these cases. However, contaminated ears had a higher postoperative infection rate (>10%), and the authors concluded that antibiotics might be helpful in these cases to prevent infection within the first postoperative week and improve patient comfort.
In an attempt to resolve the controversy over the use of prophylactic antibiotics, Hester et al.4 published a prospective, randomized, double-blinded, placebo-controlled study of 146 patients who underwent surgery for chronic otitis media and/or cholesteatoma from 1992 to 1996. Patients randomized to the antibiotic group received intravenous ampicillin/sulbactam prior to incision, followed by a 5-day course of oral amoxicillin/clavulanate. Within the first 3 weeks after surgery, there were similar wound infection rates: four postoperative infections in the placebo group (5.3%), and one infection in the antibiotic group (1.4%, P < .3); lack of significance may reflect small sample size. At 3 months postoperatively, there were similar tympanic membrane graft failure rates: seven graft failures in the placebo group (9.3%) and five graft failures in the antibiotic group (7.0%). The authors concluded that prophylactic antibiotics do not reduce postoperative infection or improve results after surgery for chronic otitis media.
In addition to systemic antibiotics, topical antibiotics are often used perioperatively for otologic surgeries. In 2002, Tong et al.5 published a prospective, randomized, single-blinded study of 101 patients undergoing type I tympanoplasty from April 1996 to December 1997. Patients were randomly assigned to receive 10-minute daily treatments with topical ofloxacin for 2 weeks preoperatively, 3-minute daily treatments for 2 weeks preoperatively, or no treatment. At 8 weeks postoperatively, tympanic membrane graft success rates were similar, ranging from 82% to 89%. Interestingly, of the 15 patients who did have graft failure, 10 had positive bacterial cultures at the time of surgery (five Staphylococcus aureus, five coagulase-negative Staphylococcus). These patients were spread across the three treatment groups. The authors concluded that although preoperative topical ofloxacin does not improve graft success in type I tympanoplasty, positive bacterial cultures at the time of surgery appear to increase the chance of graft failure.
The routine use of prophylactic antibiotics in clean otologic surgery is not supported by evidence as it does not reduce postoperative wound infection nor improve tympanic membrane graft success. The potential role of prophylactic antibiotics in contaminated otologic cases, which are at higher risk for postoperative infections, needs to be further studied with sufficient sample size and power.
LEVEL OF EVIDENCE
In this review, five level 1 studies (randomized controlled trials) were examined.