Kommerell diverticulum: distinctions between arch side, and evaluation of morphology, size, and risk.

Abstract

BACKGROUND\nKommerell diverticulum (KD) is a dilated proximal aberrant subclavian artery associated with either right or left aortic arches (RAA-ARSA or LAA-ALSA). Although case series suggest KD may be a liability for vascular complications, the risk, pattern of dilation throughout the lifespan, and differences between arch sides, are not known.\n\n\nMETHODS\nA single-center retrospective review of patients of all ages with KD on cross-sectional imaging. Maximal short axis diameter of KD (KDmax), absolute and indexed to descending aortic (DAo) diameter, was correlated with age. Comparisons were made between arch sides. Patients with vascular complications are described.\n\n\nRESULTS\nOne hundred and four patients with KD were included [68 (65%) RAA-ALSA, 36 (35%) LAA-ARSA; 43 (41%) asymptomatic]. Although KDmax was correlated with age (RAA-ALSA r=0.84 [p<.0001]; LAA-ARSA r=0.51 [p=0.001]), KDmax/DAo was not (RAA-ALSA r=0.14 [p=0.27]; LAA-ARSA r=-0.22 [p=0.21]). RAA-ALSA had larger KDmax/DAo (1.02±0.20 vs 0.89±0.18 mm/mm, p=0.002), more symptoms (75% vs 28%, p <.0001), and younger age (median 9.5 vs 61.7 years, p<.0001). Six patients had vascular complications, age 58-80 years, all with LAA-ARSA and risk factors for acquired aneurysms.\n\n\nCONCLUSIONS\nIn older patients, KDmax/DAo was not larger, arguing against isolated KD dilation with age. Diverticula from RAA-ALSA and LAA-ARSA demonstrate different phenotypes, suggesting different disease processes and likely different risk. The incidence of vascular complication was lower than previous reports, and occurred exclusively in patients with LAA-ARSA and aneurysm risk factors. This suggests conservative management of asymptomatic KD is often reasonable, especially with RAA-ALSA.