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Microscope sterility during spine surgery
Jesse E Bible1, Kevin R O'Neill, Colin G Crosby
1Vanderbilt Orthopaedic Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA. jesse.bible@vanderbilt.edu
Study Design:
Prospective study.
Objective:
Assess the contamination rates of sterile microscope drapes after spine surgery.
Summary Of Background Data:
The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection.
Methods:
This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique.
Results:
No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002).
Conclusion:
Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact with unsterile parts of the surgeon. Therefore, we believe that changing gloves after making adjustments to the optic eyepieces and avoid handling any portion of the drape above the eyepieces may decrease the risks of intraoperative contamination and possibly postoperative infection as well.
Insights
Sterile microscope drapes used in spine surgery showed significant bacterial contamination, particularly around the optic eyepieces. Implementing changes like glove changes after adjustments may reduce contamination risks.
Area of Science:
- Neurosurgery
- Surgical Technology
- Infection Control
Background:
- The operating microscope enhances visualization in spine surgery but may increase infection risk.
- Microscope drapes are used to maintain sterility during procedures.
- Assessing drape contamination is crucial for patient safety.
Purpose of the Study:
- To evaluate the bacterial contamination rates of sterile microscope drapes post-spine surgery.
- To identify specific areas on the drape prone to contamination.
Main Methods:
- A prospective study involving 25 spine surgery cases using an operating microscope.
- Swabs collected from 7 sites on microscope drapes post-surgery.
- Positive and negative controls used to validate contamination findings.
Main Results:
- All evaluated drape sites showed contamination post-surgery (12-44%).
- Significant contamination occurred on optic eyepiece shafts (24-28%) and overhead portions (44%).
- Negative controls showed no bacterial growth, confirming drape sterility before use.
Conclusions:
- Microscope drapes are significantly contaminated after spine surgery.
- Contamination is linked to touching unsterile parts, especially around eyepieces.
- Changing gloves and avoiding drape manipulation above eyepieces may reduce contamination.
