Solitary Intercostal Arterial Trunk

Abstract

D uring embryonic life, events may alter the normal growth and fusion of the endocardial tube, the paired dorsal aortae, and the vitelline plexus, leading to anomalies and variants of the mature axial arterial system. 1 Many of these are well known, especially those associated with the aorta, heart, and umbilical artery. 1,2 Vitelline variants have also been found that are either associated with Meckel diverticulum or caudal regression syndrome. 3,4 We present a case of anomalous intercostal arterial supply, which, to our knowledge, has not been reported previously. The aberrant intercostal trunk is associated with aberrant descending thoracic aorta position, a replaced common hepatic artery from the superior mesenteric artery, and an isolated splenic artery origin from the aorta.A 27-year-old man with a medical history of irritable bowel syndrome and stage I hypertension presented for renal vasculature evaluation. A renal arterial magnetic resonance angiogram (not shown) and subsequent thoracoabdominal computed tomography (CT) angiogram [64-row multidetector-row computed tomography (MDCT), 1.0-mm section thickness after intravenous injection of 600 mgI/kg Isovue 370] demonstrated normal renal arteries and an anomalous branch artery arising from the posterior aspect of the aorta at the level of T12 with median ascension, terminating at T3. The artery gradually tapered from its 7-mm diameter origin to its terminus and supplied the third through twelfth intercostal arteries bilaterally (Figure 1). This "anomalous intercostal trunk" coursed between the thoracic spine and the descending thoracic aorta, which was elevated 23 mm anterior to the thoracic vertebral bodies and was in close association with the esophagus (Figure 2). An additional posterior trunk arose at the level of T6 and ascended superiorly to supply the first and second intercostals spaces. Associated with this anomaly was an isolated splenic artery Figure 1. Frontal volume-rendered CT angiogram demonstrates the T4 -T12 intercostal arteries arising from the anomalous intercostal trunk arising from the aorta at the T12 level (arrow). Figure 2.Transverse CT section demonstrates centralized apices of the hemidiaphragms. In the upper abdomen, the aorta (A) is anteriorly displaced from the vertebrae and the anomalous trunk (curved arrow) occupies the prevertebral space. Fat occupies the space in the middle mediastinum between the aorta and vertebrae. The online-only Data Supplement is available at http://circimaging.ahajournals.org/cgi/content/full/2/6/e49/DC1.

Case report: persistent double dorsal aorta

“…The most observed variation within the category of complete separation of the dorsal aortas consists of presence of a principal dorsal aorta in conjunction with an accessory ascending aorta, which, in the majority of cases, runs to supply the posterior intercostal arteries. 3,[11][12][13][14][15][16] The anomaly presented in the current report is similar to the pattern reported by Mosquera and Micarelli, 4 who described complete separation of two dorsal aortas into branches of the same caliber: one ventral and the other dorsal.…”

“…3,8 Trubnikov et al 9 and Khristova et al 10 describe a descending aorta pattern in which there is a double lumen separated by a central dividing septum. The second, more prevalent pattern, has been described by Mosquera and Micarelli, 4 Eibach and Walter, 11 Formanek et al, 12 Brew et al, 13 Karadeli and Ulu, 8 Chang and Rubin, 14 Edwards et al, 15 Jie et al, 16 Mills and Gest 3 and Hurtado et al, 5 and consists of complete separation of the two portions of the dorsal aorta.…”

“…Trubnikov et al 9 e Khristova et al 10 reportaram um padrão de aorta descendente de duplo lúmen com a presença de um septo divisor central. O segundo, mais prevalente, descrito por Mosquera e Micarelli 4 , Eibach e Walter 11 , Formanek et al 12 , Brew et al 13 , Karadeli e Ulu 8 , Chang e Rubin 14 , Edwards et al 15 , Jie et al 16 , Mills e Gest 3 e Hurtado et al 5 , consiste na completa separação das duas porções da aorta dorsal.…”

Relato de caso: aorta dorsal dupla persistente

“…A variação mais observada dentre a categoria da completa separação das aortas dorsais compõe-se da presença de uma aorta dorsal principal em associação a uma aorta acessória ascendente, a qual, na maioria dos casos, dirige-se para irrigar as artérias intercostais posteriores 3,[11][12][13][14][15][16] . A anomalia apresentada nesse relato assemelha-se ao padrão reportado por Mosquera e Micarelli 4 , onde descreveram a completa separação das duas aortas dorsais em ramos de mesmo calibre: um ventral e outro dorsal.…”

“…As malformações ocorrem, principalmente, no sistema renal, vascular ou esquelético, em especial no esqueleto axial, associadas ou não. Além disso, são descritas aberrações cardíacas, pulmonares, glandulares, intestinais e genitais 3,4,9,[11][12][13][14][15][16] . Em associação ao defeito embriológico apresentado por esse caso, observouse uma anomalia na origem da mesentérica inferior, que formou-se da parede anterior do ramo posterior da aorta dorsal.…”