Minimally invasive transforaminal lumbar interbody fusions and fluoroscopy: a low-dose protocol to minimize ionizing radiation.

OBJECT: There is an increasing awareness of radiation exposure to surgeons and the lifelong implications of such exposure. One of the main criticisms of minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is the amount of ionizing radiation required to perform the procedure. The goal in this study was to develop a protocol that would minimize the fluoroscopy time and radiation exposure needed to perform an MIS TLIF without compromising visualization of the anatomy or efficiency of the procedure.

METHODS

A retrospective review of a prospectively collected database was performed to review the development of a low-dose protocol for MIS TLIFs in which a combination of low-dose pulsed fluoroscopy and digital spot images was used. Total fluoroscopy time and radiation dose were reviewed for 50 patients who underwent single-level MIS TLIFs.

RESULTS

Fifty patients underwent single-level MIS TLIFs, resulting in the placement of 200 pedicle screws and 57 interbody spacers. There were 28 women and 22 men with an average age of 58.3 years (range 32-78 years). The mean body mass index was 26.2 kg/m(2) (range 17.1-37.6 kg/m(2)). Indications for surgery included spondylolisthesis (32 patients), degenerative disc disease with radiculopathy (12 patients), and recurrent disc herniation (6 patients). Operative levels included 7 at L3-4, 40 at L4-5, and 3 at L5-S1. The mean operative time was 177 minutes (range 139-241 minutes). The mean fluoroscopic time was 18.72 seconds (range 7-29 seconds). The mean radiation dose was 0.247 mGy*m(2) (range 0.06046-0.84054 mGy*m(2)). No revision surgery was required for any of the patients in this series.

CONCLUSIONS

Altering the fluoroscopic technique to low-dose pulse images or digital spot images can dramatically decrease fluoroscopy times and radiation doses in patients undergoing MIS TLIFs, without compromising image quality, accuracy of pedicle screw placement, or efficiency of the procedure.