Prenatal Diagnosis of an Aortopulmonary Window With an Interrupted Aortic Arch.

A prenatal aortopulmonary window with an interrupted aortic arch was detected in a 22-week-old fetus. The 3-vessel and trachea view showed a communication between the ascending aorta and the pulmonary artery. Early postnatal surgery was successful. A PubMed-based search identified all cases of prenatal aortopulmonary windows between 2002 and 2015. Nine articles were identified. The average gestational age at diagnosis was 28 weeks (range, 22-33 weeks). The most frequent aortopulmonary window was type I (40%). All cases were associated with congenital heart defects, mainly an interrupted aortic arch (50%). No chromosomal or extracardiac abnormalities were seen. Prenatal echocardiography is useful for early diagnosis of an aortopulmonary window. The prognosis depends on the time of surgery and the nature of the associated anomalies.

Vascular rings.

The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time.

Central stiffening in adulthood linked to aberrant aortic remodeling under suboptimal intrauterine conditions.

This study examined perturbed aortic development and subsequent wall stiffening as a link to later cardiovascular disease. Placental insufficiency was induced in pregnant guinea pigs at midgestation by uterine artery ligation. Near term, fetuses were killed and defined as normal birth weight (NBW), low birth weight (LBW), and intrauterine growth restricted (IUGR). Offspring were classified according to birth weight and killed in adulthood. Collagen and elastin content of aortas were analyzed using Sirius red and orcein staining, respectively. Immunofluorescence was used for detection of α-actin and nonmuscle myosin heavy chain (MHC-B), a marker of synthetic-type vascular smooth muscle cells (VSMCs). Ex vivo generation of length-tension curves was performed with aortic rings from adult offspring. Relative elastic fiber content was decreased by 10% in LBW and 14% in IUGR compared with NBW fetuses. In adulthood, relative elastic fiber content was 51% lower in LBW vs. NBW, and the number of elastic laminae adjusted for wall thickness was 25% lower in LBW (P < 0.01). The percent area stained for MHC-B was sixfold higher in LBW vs. NBW fetuses (P < 0.0001) and threefold higher in LBW vs. NBW adult offspring (P < 0.05). The increase in MHC-B in LBW offspring concurred with a 41% increase in total collagen content and a 33 and 56% increase in relative and total α-actin content, respectively (P < 0.05). Thus aortic wall stiffening in adulthood can be traced to altered matrix composition established under suboptimal intrauterine conditions that is amplified postnatally by the activity of synthetic VSMCs.

Prenatal diagnosis of left ventricular aneurysm in association with interruption of the aortic arch.

Left ventricular aneurysms in the foetus are a rare abnormality that can occur in isolation or associated with pentalogy of Cantrell. Here, we report a case of a foetus with a left ventricular aneurysm in association with interruption of the aortic arch, and no features of pentalogy of Cantrell. To our knowledge, this is the first report of such an association.

Ischemia is not required for arteriogenesis in zebrafish embryos.

OBJECTIVE: The role of ischemia in collateral vessel development (arteriogenesis) is a contentious issue that cannot be addressed using mammalian models. To investigate this, we developed models of arteriogenesis using the zebrafish embryo, which gains sufficient oxygenation via diffusion to prevent ischemia in response to arterial occlusion. METHODS AND RESULTS: We studied gridlock mutant embryos that suffer a permanently occluded aorta and show that these restore aortic blood flow by collateral vessels. We phenocopied gridlock mutants by laser-induced proximal aortic occlusion in transgenic Fli1:eGFP/GATA1:dsRED embryos. Serial imaging showed these restore aortic blood flow via collateral vessels by recruitment of preexisting endothelium in a manner similar to gridlocks. Collateral aortic blood flow in gridlock mutants was dependent on both nitric oxide and myeloid cells. Confocal microscopy of transgenic gridlock/Fli1:eGFP mutants demonstrated no aberrant angiogenic response to the aortic occlusion. qPCR of HIF1alpha expression confirmed the absence of hypoxia in this model system. CONCLUSIONS: We conclude that NO and myeloid cell-dependent collateral vessel development is an evolutionarily ancient response to arterial occlusion and is able to proceed in the absence of ischemia.

Injury of an aberrant subclavian artery: a rare complication of video assisted thoracoscopic esophagectomy.

An aberrant right subclavian artery is an uncommon anomaly. When associated with esophageal cancer, it can cause diagnostic confusion as the symptoms are similar. If unrecognized and injured during esophageal surgery, it can lead to disastrous complications. We report a patient in whom this aberrant artery was injured during a thoracoscopic mobilization of the esophagus. The embryological and radiologic aspects of this anomaly and its clinical significance are discussed. Pre-operative diagnosis will require a high index of suspicion, as the clinical and radiological features are not specific. If injury occurs, an immediate vascular reconstruction will prevent limb ischemia and hence knowledge of this entity is of utmost importance.

Embryology, anatomy, and surgical exposure of the great abdominal vessels.

This article describes the embryology of the abdominal aorta and the anatomic features of its major visceral branches, including the celiac, superior mesenteric, and inferior mesenteric arteries. The common anatomic variants of these visceral vessels also are reviewed. Various operative techniques to gain surgical exposure to these vessels are described.

Unique vascular morphology of the fourth aortic arches: possible implications for pathogenesis of type-B aortic arch interruption and anomalous right subclavian artery.

OBJECTIVE: Neural crest-derived cells were previously shown to participate in vessel wall formation of the great thoracic arteries, and their contribution was proposed to affect morphology and physiology of these vessels in the chick. The present investigation was undertaken to examine vascular differentiation and morphogenesis of the neural crest-derived aortic arches in mammals. METHODS: Using immunohistochemical markers for smooth muscle cell differentiation and a neurofilament marker, we examined morphogenesis of the great arteries in mice, ranging from embryonic day 11.5 to the adult. RESULTS: We observed that in the 4th aortic arch arteries early media formation differed from the other arteries, in that they almost completely lacked (or showed decreased) actin expression in certain areas. This discontinuity in actin expression persisted throughout much of foetal development, in the form of circular segments of cells displaying decreased staining for smooth muscle markers, both at the left and right side of the arterial tree. In adult mice, the 4th arch artery derivatives, segment B of the aortic arch and the proximal right subclavian artery, were observed to differ from adjoining vessels in their smooth muscle and elastic composition. Staining for neurofilaments revealed close association of the developing segments with apparent sensory afferent vascular innervation. CONCLUSION: The unique areas of the 4th arch artery identified here reflect the basic segmental patterning of the early embryonic pharyngeal arches. These segments correlate with sites that are predisposed to interruption or severe hypoplasia, and may thus reveal part of the aetiology of type-B aortic arch interruptions and arteria lusoria.

The aortic diverticulum: a remnant of the partially involuted dorsal aortic root.

The aortic diverticulum, a large bulge on the lesser curvature of the aortic isthums, is an occasional variation found during thoracic aortography in patients with a left aortic arch and normal origin of the brachiocephalic arteries. Although it is commonly thought to be a remnant of the closed ductus arteriosus, the results of this study support the hypothesis that it is a remnant of the right dorsal aortic root.