Radiation Exposure to the Surgeon During Open Lumbar Microdiscectomy and Minimally Invasive Microdiscectomy

TLDR

Fluoroscopy during lumbar microdiscectomy exposes surgeons to ionizing radiation, yet the magnitude of exposure during minimally invasive procedures remains unknown. The study prospectively compared surgeon radiation exposure during 10 minimally invasive lumbar microdiscectomy cases with 10 traditional open discectomy cases. Using digital dosimeters placed at the thyroid/eye, chest, and dominant forearm, the authors measured radiation in 20 cases, collected operative details, and applied Occupational Exposure Guidelines to estimate allowable case numbers. Surgeons experienced significantly higher radiation during MIS (thyroid/eye 1.72 mR, chest 3.08 mR, hand 4.45 mR) versus open cases (0.16 mR, 0.21 mR, 0.20 mR), with differences statistically significant and requiring many thousands of MIS cases to reach exposure limits; substerile room protection was inadequate.

Abstract

This is a prospective in vivo study comparing radiation exposure to the surgeon during 10 minimally invasive lumbar microdiscectomy cases with 10 traditional open discectomy cases as a control.Radiation exposure to the eye, chest, and hand of the operating surgeon during minimally invasive surgery (MIS) and open lumbar microdiscectomy were measured. The Occupational Exposure Guidelines were used to calculate the allowable number of cases per year from the mean values at each of the 3 sites.Fluoroscopy is a source of ionizing radiation and as such, is a potential health hazard with continued exposure during surgery. Presently, radiation exposure to the surgeon during MIS lumbar microdiscectomy is unknown.Radiation exposure to the surgeon (millirads [mR]) per case was measured by digital dosimeters placed at the level of the thyroid/eye, chest, and dominant forearm. Other data collected included operative side and level, side of the surgeon, side of the x-ray source, total fluoroscopy time, and energy output.The average radiation exposure to the surgeon during open cases was thyroid/eye 0.16 ± 0.22 mR, chest 0.21 ± 0.23 mR, and hand 0.20 ± 0.14 mR. During minimally invasive cases exposure to the thyroid/eye was 1.72 ± 1.52 mR, the chest was 3.08 ± 2.93 mR, and the hand was 4.45 ± 3.75 mR. The difference between thyroid/ eye, chest, and hand exposure during open and minimally invasive cases was statistically significant (P = 0.010, P = 0.013, and P = 0.006, respectively). Surgeons standing in an adjacent substerile room during open cases were exposed to 0.2 mR per case.MIS lumbar microdiscectomy cases expose the surgeon to significantly more radiation than open microdiscectomy. One would need to perform 1623 MIS microdiscectomies to exceed the exposure limit for whole-body radiation, 8720 cases for the lens of the eye, and 11,235 cases for the hand. Standing in a substerile room during x-ray localization in open cases is not fully protective.