Oral versus single intravenous bolus dose antibiotic prophylaxis against postoperative surgical site infection in external dacryocystorhinostomy for primary acquired nasolacrimal duct obstruction – A randomized study

Purpose: To compare the efficacy of a single perioperative bolus dose of intravenous antibiotic versus postoperative oral antibiotic prophylaxis for prevention of surgical site infection (SSI) in external dacryocystorhinostomy (DCR) for primary acquired nasolacrimal duct obstruction (PANDO). Methods: This was a prospective randomized controlled study with a noninferiority design. Patients undergoing external DCR surgery were randomized into two groups A and B. Patients in group A received a single bolus dose of intravenous cefazolin 1 g at surgery, whereas those in group B received oral cephalexin 500 mg postoperatively twice a day for 5 days. Allocation concealment was ensured by sequentially numbered opaque sealed envelopes (SNOSEs). Both groups were advised identical postoperative local wound care regimens. Any clinical evidence of SSI at 4 weeks of follow-up in either group was the main outcome measure. Results: In all, 338 patients randomized into two groups of 169 patients each participated in this study. At follow-up of 4 weeks, only one patient in group B developed postoperative SSI. None in group A developed postoperative SSI. Other potential risk factors for postoperative SSI were also analyzed by univariate and multivariate analyses but none achieved statistical significance in either group. Conclusion: Our results demonstrate that a single bolus dose of perioperative intravenous antibiotic offers adequate prophylaxis against postoperative SSI and compares favorably with the more commonly used oral antibiotic prophylaxis in external DCR for PANDO in our population and our practice scenario.