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Quantification of incidental needle and suture contamination during strabismus surgery
Thomas S Carothers1, David K Coats, Kathryn M B McCreery
1Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, USA.
Purpose:
To quantify the level of bacterial contamination of needles and sutures immediately after use in strabismus surgery.
Methods:
Strabismus surgery was performed on 56 eyes from 31 pediatric strabismus surgical cases. Preoperative site preparation included instillation of 5% povidone-iodine in the conjunctival fornices in all cases. A total of 124 needles and 127 sutures were cultured immediately after final scleral passage.
Results:
Seventeen of the 31 cases (54.8%) produced at least one positive specimen. Nineteen per cent of the needles and 25.2% of the sutures were culture positive. The bulk of positive specimens (96.7% of needles, 91.3% of sutures) produced 3 or less colony forming units, corresponding to 7 or less total viable organisms per needle or sutures in accordance with the dilution scheme. Coagulase-negative staphylococci overwhelmingly predominated.
Conclusions:
Needles and sutures used in strabismus surgery can become contaminated during surgery despite preoperative povidone-iodine preparation. The number of viable bacterial contaminants is usually below the level known to consistently produce experimental endophthalmitis. However, a few needles and sutures carried a high contaminant load, suggesting the possibility that contaminated needles and sutures could potentially cause postoperative intraocular infection.
Insights
Bacterial contamination of needles and sutures is common after strabismus surgery, even with povidone-iodine. While usually low-level, some contaminated surgical materials may pose a risk for intraocular infection.
Area of Science:
- Ophthalmology
- Microbiology
- Surgical Infection Control
Background:
- Strabismus surgery involves delicate instruments like needles and sutures.
- Maintaining sterility during ophthalmic procedures is crucial to prevent infections.
- Povidone-iodine is a standard antiseptic used for surgical site preparation.
Purpose of the Study:
- To quantify bacterial contamination levels on needles and sutures post-strabismus surgery.
- To assess the effectiveness of preoperative povidone-iodine in reducing contamination.
- To identify potential sources of postoperative intraocular infection.
Main Methods:
- Culturing of 124 needles and 127 sutures immediately after use in 31 pediatric strabismus cases.
- Standard preoperative antiseptic preparation with 5% povidone-iodine was applied to all cases.
- Analysis of bacterial colony counts and identification of predominant organisms.
Main Results:
- Over half (54.8%) of the surgical cases yielded at least one positive culture.
- 19% of needles and 25.2% of sutures showed bacterial contamination.
- Coagulase-negative staphylococci were the most common contaminants, typically in low numbers (≤7 organisms per item).
Conclusions:
- Surgical needles and sutures can become contaminated during strabismus surgery despite antiseptic preparation.
- The bacterial load is generally low, but a small number of items had high contamination.
- Contaminated surgical materials, though infrequent, may represent a risk factor for postoperative intraocular infections.