Association between aortic pathology, surgeon experience, and regional variability on use of intravascular ultrasonography during thoracic endovascular aortic repair

Objective

Intravascular ultrasound (IVUS) is a useful adjunct to obtain precise intraluminal measurements during thoracic endovascular aortic repair (TEVAR), but IVUS examination is not routinely used by all surgeons or centers during TEVAR. We sought to identify patient- and system-related factors that influence the decision to use IVUS examination during TEVAR.

Methods

A retrospective review of the Vascular Quality Initiative (VQI) database was performed to identify all patients undergoing TEVAR from 2015 to 2019. Multivariable logistic regression modeling with three-fold repeated cross-validation was performed to identify predictors of IVUS use during TEVAR. Association of IVUS use with contrast volume and radiation exposure was also assessed.

Results

A total of 12,414 patients undergoing TEVAR met the inclusion criteria. Of these, IVUS examination was used in 41.3% of cases (n = 5121). IVUS use was more common in younger patients with fewer comorbidities; however, IVUS examination was also more commonly deployed in symptomatic patients and those with a higher preoperative American Society of Anesthesiology classification. IVUS examination was use in 80% (n = 3385/4213) TEVAR procedures performed for type B aortic dissection, which accounted for 50% of total IVUS use and only 11% of cases during which IVUS examination was not used (n = 822/7293) (P < .01). In multivariable analysis, the strongest independent predictor of IVUS use was aortic dissection (odds ratio, 13.7; 95% confidence interval, 11.7-16.3; P < .001, with aortic aneurysm as the reference). Surgeon years of independent practice experience was not associated with IVUS use, but when accounting for clustering on physicians and geographic regions, these variables explained 15% of the variance observed in the final risk-adjusted model. After adjustment for confounding factors, IVUS use was associated with a significant decrease in fluoroscopy time and contrast volume (both P < .001).

Conclusions

The decision to use IVUS examination during TEVAR is most heavily influenced by aortic pathology. Although surgeon experience was not associated with the decision to use IVUS examination, there was substantial variation in IVUS examination use among individual surgeons and VQI regions. IVUS use was associated with decreased contrast administration and fluoroscopy use but did not appear to have an impact on survival or re-intervention. Although aortic dissection was strongly associated with IVUS use, a significant number of TEVAR for dissection were performed without IVUS examination. Further research is warranted to identify the barriers to IVUS use as well as the risks and benefits of IVUS use during TEVAR so that quality benchmarks can be established and resource use is improved.