Microscope sterility during spine surgery

Surgery

Spine 2012;37:623–627

Title:

Microscope sterility during spine surgery

Authors

Bible JE

O'Neill KR

Crosby CG

Schoenecker JG

McGirt MJ

Devin CJ.

Study Design.

Prospective study

Objective.

Assess the contamination rates of sterile microscope drapes after spine surgery

Summary of Background Data.

1. Prevalent usage of operating microscope

   *Superior magnification, visualization, illumination of operative field

2. However, additional source of bacterial contamination and the infection risk.

Methods.

1. 25 cases by single spine surgeon using operative microscope

2. Sterile culture swabs to obtain samples from 7 defined locations on the microscope drape after operation

3. Undraped technician's console was sampled in each case as a positive control

4. Additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls.

5. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semi-quantitative technique.

Results.

1. No growth on any of the 25 negative control drapes

2. But obvious contamination

*100% of preoperative and 96% of postoperative positive controls

3. In the postoperative group

*All 7 sites were contaminated (12% ~ 44%).

*4 of 7 locations: significant contamination 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.

1. Bacterial contamination of the microscope was found to be significant after surgery.

2. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions.

3. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact with unsterile parts of the surgeon.

4. Therefore, recommendations

*Changing gloves after making adjustments

*Avoiding handling any portion of the drape above the eyepieces

5. Microscope can be a potential source of contamination.

"This comes from Spine (c) 2012 Lippincott Williams & Wilkins, Inc."