LAUSR

Adrenal vein sampling (AVS) is experiencing a renaissance of sorts for a variety of reasons. While this procedure is well over 50 years old, for the first several decades of its existence it was hampered by published reports of poor outcomes, with diagnostic failure usually due to unsuccessful sampling of the right adrenal vein. There is rising demand for AVS due to increasing recognition of primary aldosteronism as an important and potentially surgically treatable cause of hypertension coupled with improved outcomes from the procedure. The latter has been the result of multiple valuable technical refinements to the procedure published over the past 20 years. These include description of the inferior emissary vein sign [1], preoperative CT [2] and the use of intra-procedure cone beam computed tomography (CBCT) [3] to help less experienced operators localize and successfully sample the right adrenal vein in particular. In this issue of CVIR, Hafezi-Nejad et al. have provided a systematic review based on publications describing the use of CBCT [4] and demonstrated that there is improved operator success using CBCT compared to not using it. The authors also found that certain demographic characteristics made the use of CBCT more valuable, including higher BMI and younger age. The authors temper their conclusions appropriately by stating that intra-procedural CT should not be used all the time, but rather selectively. Indeed, since there is significant radiation associated with CBCT, judicious application of this technology should be the rule. The authors suggest that less experienced operators or difficult cases would be criteria for the use of CBCT. Readers expert in AVS are likely to scoff at the conclusions of this paper, since those with extensive experience in AVS over the course of decades of practice can achieve technical success rates of 99% without the use of CBCT. It’s almost always the senior members of an IR division who offer AVS, and for good reason-AVS takes time to learn to do well. Further, the studies included in the systematic review have non-CBCT rates that are very poor (40.6–91.8%, pooled 72.7%), and CBCT-assisted rates that are still poor compared to any experienced operator (76.5%-98.4%, pooled 92.5%). But that’s beside the point. Rather than successful AVS being limited to the older interventional radiologists in the department who have that experience, the introduction of these new techniques can help younger interventional radiologists get comfortable with AVS as quickly as possible, and as their practices grow, they will rapidly learn that they do not need to use CBCT very often or indeed perhaps not even at all. In turn, as these practices flourish based on the performance of high success rates in AVS, referrals are likely to increase as the general skepticism about AVS fades into the background over time. More widely available high quality AVS is better for our specialty and more importantly, better for patients. Perhaps the biggest challenge offered by this study is deciding exactly when an AVS operator no longer needs the support of CBCT, and weaning that operator from it. One would hope that the additional intra-procedural time needed for CBCT as well as the additional radiation dose would pay off in the form of a steeper learning curve and & Scott O. Trerotola [email protected]