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Occurrence of a type 2 proatlantal intersegmental artery during carotid endarterectomy for symptomatic stenosis

2016; Elsevier BV; Volume: 64; Issue: 3 Linguagem: Inglês

10.1016/j.jvs.2014.10.100

1097-6809

Joseph Liechty, Rebecca Jo Weddle, William P. Shutze, Bertram L. Smith,

Moyamoya disease diagnosis and treatment

A 63-year-old female patient presented with transient right hand weakness and left amaurosis fugax. A computed tomography angiogram demonstrated a 75% to 90% internal carotid artery (ICA) stenosis and a persistent proatlantal intersegmental artery (PAIA) originating from the external carotid artery (ECA), passing lateral to the internal jugular vein (A), and joining the ipsilateral vertebral artery. The PAIA was the major contributor to the basilar artery. Also noted were an absent left cervical vertebral artery and a hypoplastic right vertebral artery terminating as the posterior inferior cerebellar artery. Intraoperatively, the PAIA was identified as a posterior-oriented branch of the ECA (B). A shunt was placed from the common carotid artery to the ICA. Pulsatile back-bleeding was seen from the ECA/PAIA origin, and this was not shunted. Endarterectomy and patch was performed, and the ECA/PAIA was treated with an eversion endarterectomy only. The patient had a normal convalescence and was discharged the following day. A follow-up three-dimensional computed tomography angiogram demonstrated a satisfactory patch repair with patency of all intracranial and extracranial arteries (C/Cover). The hindbrain in the 4-mm to 5-mm embryo is supplied by two longitudinal neural arteries connected to the carotid circulation by four named sets of transient arteries. The nearly eponymous superior three sets travel with three cranial nerves: the trigeminal (V), hypoglossal (XII), and otic (VIII). The fourth set, the PAIA, does not follow a cranial nerve. It passes via the suboccipital region, traverses the foramen magnum, and then fuses with the horizontal portion of the vertebral artery. The trigeminal, hypoglossal, and otic arteries involute as the neural arteries fuse to form the basilar artery.1Ouriel K. Green R.M. DeWeese J.A. Anomalous carotid-basilar anastomoses in cerebrovascular surgery.J Vasc Surg. 1988; 7: 774-777Abstract Full Text PDF PubMed Scopus (58) Google Scholar The PAIA persists until the cervical vertebral arteries have formed from transverse anastomoses between adjacent intersegmental arteries of the spine when the embryo is 7 to 12 mm.1Ouriel K. Green R.M. DeWeese J.A. Anomalous carotid-basilar anastomoses in cerebrovascular surgery.J Vasc Surg. 1988; 7: 774-777Abstract Full Text PDF PubMed Scopus (58) Google Scholar A PAIA may persist in the adult as an anomalous vascular connection between the carotid and ipsilateral vertebral arterial systems. Nomenclature of the PAIA has been divided according to the vessel of origin: type 1-ICA and type 2-ECA.2Lasjaunias P. Theron J. Moret J. The occipital artery, anatomy, normal arteriographic aspects, embryological significance.Neuroradiology. 1978; 15: 31-37Crossref PubMed Scopus (106) Google Scholar When a PAIA is present, associated expected anomalies include an aplastic ipsilateral and hypoplastic contralateral vertebral artery as well as an aberrant pattern of communicating arteries within the circle of Willis.2Lasjaunias P. Theron J. Moret J. The occipital artery, anatomy, normal arteriographic aspects, embryological significance.Neuroradiology. 1978; 15: 31-37Crossref PubMed Scopus (106) Google Scholar