Use of Antibiotic-Impregnated Absorbable Beads and Tissue Coverage of Complex Wounds

A Scoping Review on the Use of Antibiotic-Impregnated Beads and Applications to Vascular Surgery

INTRODUCTION

Surgical site infection (SSI) presents a ubiquitous concern to surgical specialties, especially in the presence of prosthetic material. Antibiotic-impregnated beads present a novel and evolving means to combat this condition. This review aims to analyze the quality of evidence and methods of antibiotic bead use, particularly for application within vascular surgery.

METHODS

A systematic scoping review was conducted within Embase, MEDLINE, and the Cochrane Registry of Randomized Controlled Trials. Articles were evaluated by 2 independent reviewers. Level of evidence was evaluated using the Oxford Center for Evidence-Based Medicine Criteria and the Cochrane Risk of Bias Tool for Randomized Controlled Trials.

RESULTS

The search yielded 6951 papers, with 275 included for final analysis. Publications increased in frequency from 1978 to the present. The most common formulation was polymethyl methacrylate; however publications on biodegradable formulations, including calcium sulfate beads, have been published with increasing frequency. Most publications had positive conclusions (94.2%); however, the data was mainly subjective and may be prone to publication bias. Only 11 randomized controlled trials were identified and all but one was evaluated to be at a high risk of bias. The most common indication was for osteomyelitis (52%), orthopedic prosthetic infections (20%), and trauma (9%). Within vascular surgery, beads have been used primarily for the treatment of graft infection, with freedom from recurrence rates being reported from 41% to 87.5%.

CONCLUSIONS

Antibiotic-impregnated beads provide a means to deliver high doses of antibiotic directly to a surgical site, without the risks of parenteral therapy. There has yet to be significant high-level quality data published on their use. There is a large body of evidence that suggests antibiotic beads may be used in SSIs in high-risk patients, prosthetic infections, and other complex surgical infections. Important potential areas of application in vascular surgery include graft infection, prevention of wound infection in high-risk patients, and diabetic foot infection.

A Single Center Retrospective Evaluation of a Surgical Strategy to Combat Persistent Soft Tissue Wounds Utilizing Absorbable Antibiotic Beads

Objective: To determine whether use of absorbable antibiotic-imbued beads in chronic soft tissue wounds presents a viable therapeutic modality. Approach: Retrospective analysis of all cases utilizing calcium sulfate antibiotic beads was conducted. Cases comprised complex wound and breast reconstruction performed by the senior author (C.P.D.) over 4 years at the University of New Mexico Hospital. All-cause need for reoperation and reoperation for infection in the 90 days following bead-assisted surgery were compared to traditional surgical intervention in the 90-day period preceding bead-assisted surgery. Paired-samples t-test and corrected Cohen's d were calculated for outcome significance and effect size. Results: A total of 60 patients underwent 84 bead-assisted surgeries. There was a significant decrease in rate of reoperation following bead surgery (M = 0.32) compared with prebead surgery (M = 2.2), p < 0.001. Rate of reoperation for infection significantly decreased from 1.7 before bead surgery to 0.05 following bead surgery, p < 0.001. Results remained significant when stratified by complex wound or breast reconstruction, p < 0.01. Cohen's d ranged from 1.25 to 2.13, with probability of superiority between 80% and 93%. Innovation: Use of antibiotic-laden materials is well established in the orthopedic literature, but poorly characterized in soft tissue applications. Biofilms are increasingly implicated as a unifying pathologic foe underlying chronic wound infection and nonhealing. Antibiotic beads have demonstrated activity against biofilm in vitro. This study demonstrates diminished reoperative burden for these wounds following antibiotic bead surgery, possibly as a result of in vivo biofilm antagonism. Conclusion: Antibiotic bead-assisted surgery was associated with significantly decreased infectious and all-cause reoperations for chronic and infected wounds.