CT angiography for anterior lumbar spine access: high radiation exposure and low clinical relevance.

Abstract

Some spine surgeons perform CT angiography for detailed planning of anterior access to the lumbar spine. However, the value of this imaging method and its influence on surgeons' decisions are unclear. We determined (1) the dose of radiation used in preoperative CT angiography and (2) whether CT angiography affects planning of anterior lumbar spine surgeries. We assessed preoperative CT angiograms of 28 patients undergoing anterior spine surgery. The level of aortic bifurcation, iliac vein confluence, course of the ascending lumbar vein, central sacral vessels, and any vascular variation were mapped. We determined the effective dose of radiation and recorded whether the preoperative CT angiography influenced surgical planning. We observed variations in the location of the aortic bifurcation and the iliac vein confluence. In 32% of patients, there were accessory renal arteries originating from the aorta; 7% had a rudimentary persistent left-sided caval vein. The findings did not change the plan for surgery in any patient. We detected high organ radiation dosages (mSv) for the stomach (63 mSv), liver (58 mSv), urinary bladder (47 mSv), and colon (46 mSv); other high exposure dosages involved the lungs, bone marrow, ovaries, and uterus. About one in 1919 men and one in 2971 women undergoing CT angiography therefore are expected to have colon cancer develop, and one in 2781 men and one in 2856 women are expected to have cancer of the urinary bladder develop. CT angiography is of low value for preoperative planning for anterior access to the lumbar spine and should be avoided to prevent radiation-induced damage. Level II, diagnostic study.