Sternocleidomastoid flap for pedicled reconstruction in head & neck surgery- revisiting the anatomy and technique

Background Previous studies on sternocleidomastoid flaps, have defined the importance of preserving sternocleidomastoid (SCM) branch of superior thyroid artery (STA). This theory drew criticism, as this muscle is known to be a type II muscle, i.e., the muscle has one dominant pedicle (branches from the occipital artery at the superior pole) and smaller vascular pedicles entering the belly of muscle (branches from STA and thyrocervical trunk) at the middle and lower pole respectively. It was unlikely for the SCM branch of STA to supply the upper and lower thirds of the muscle. We undertook a cadaveric angiographic study to investigate distribution of STA supply to SCM muscle. Methods It is a cross-sectional descriptive study on 10 cadaveric SCM muscles along with ipsilateral STA which were evaluated with angiography using diatrizoate (urograffin) dye. Radiographic films were interpreted looking at the opacification of the muscle. Results were analyzed using frequency distribution and percentage. Results Out of ten specimens, near complete opacification was observed in eight SCM muscle specimens. While one showed poor uptake in the lower third of the muscle, the other showed poor uptake in the upper third segment of muscle. Conclusion Based on the above findings we suggest to further investigate sternocleidomastoid muscle as a type III flap, as the STA branch also supplies the whole muscle along with previously described pedicle from occipital artery. However, this needs to be further corroborated intra-operatively using scanning laser doppler. This also explains better survival rates of superior thyroid artery based sternomastoid flaps.

Massive Hemoptysis Treated with Embolization Of an Ectopic Bronchial Artery Arising from the Right Thyrocervical Trunk: A Case Report

Background: Ectopic bronchial artery and non-bronchial systemic arteries may be the culprit vessels of hemoptysis. The main cause of clinical failure of bronchial artery embolization is incomplete embolization caused by the misidentification of the culprit arteries by conventional angiography. Multidetector computed tomography angiography is useful for visualizing the culprit arteries. Case presentation: An 82-year-old man was admitted with hemoptysis. Preprocedural multidetector computed tomography angiography revealed an ectopic bronchial artery branching from the right thyrocervical trunk. Superselective embolization of the ectopic bronchial artery was performed using gelatin sponge particles and metallic coils. Hemoptysis was controlled by this procedure without any associated complications. Conclusions: Ectopic bronchial arteries originating from the thyrocervical trunk are rare. Preprocedural multidetector computed tomography angiography is useful for visualizing the culprit arteries of hemoptysis, especially if a patient has an ectopic bronchial artery or an ectopic non-bronchial systemic artery.

Sternocleidomastoid Flap for Pedicled Reconstruction in Head & Neck Surgery- Revisiting the Anatomy and Technique

Background: Previous studies on sternocleidomastoid flaps, have defined the importance of preserving sternocleidomastoid (SCM) branch of superior thyroid artery (STA). This theory drew criticism, as this muscle is known to be a type II muscle, i.e., the muscle has one dominant pedicle (branches from the occipital artery at the superior pole) and smaller vascular pedicles entering the belly of muscle (branches from STA and thyrocervical trunk) at the middle and lower pole respectively. It was unlikely for the SCM branch of STA to supply the upper and lower thirds of the muscle. We undertook a cadaveric angiographic study to investigate distribution of STA supply to SCM muscle.Methods: It is a prospective study on 10 cadaveric SCM muscles along with ipsilateral STA which were evaluated with angiography using diatrizoate (urograffin) dye. Radiographic films were interpreted looking at the opacification of the muscle. Results were analyzed using frequency distribution and percentage. Results:Out of ten specimens, near complete opacification was observed in eight SCM muscle specimens. While one showed poor uptake in the lower third of the muscle, the other showed poor uptake in the upper third segment of muscle. Conclusion: Based on the above findings we propose to re-classify sternocleidomastoid flap as a type III flap as the STA branch also supplies the whole muscle along with previously described pedicle from occipital artery. However, this needs to be further corroborated intra-operatively using scanning laser doppler.

Suprascapular Artery Aneurysm Secondary to Severe Shoulder Joint Osteoarthritis

Aneurysms of the thyrocervical trunk and collateral branches are rarely encountered. Upon literature review, no documented cases of a suprascapular artery aneurysm resulting from osteoarthritis have been previously described. A 64-year-old female was found to have focal aneurysmal formation within the suprascapular artery. The extensive osteoarthritic changes to the glenoid, including medialization of her joint line, is hypothesized to have led to arterial injury and the observed aneurysm formation. Chronic mechanical stress on small vessels from abnormal bony contact in the setting of osteoarthritis can lead to aneurysmal formation. Arthritis as a cause of aneurysm formation in collateral vessels of the thyrocervical trunk has not been previously described.

Four collateral circulation pathways were observed after common carotid artery occlusion

Background: Common carotid artery (CCA) occlusion (CCAO) is a rare condition. Owing to collateral circulation, ipsilateral internal carotid artery (ICA) and external carotid artery (ECA) are often patent. Methods: This study included 16 patients with unilateral CCAO and patent ipsilateral ICA and ECA. The pathways which supplied ICA were investigated by digital subtraction angiography (DSA), transcranial Doppler (TCD), magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Results: In all 16 patients, TCD found antegrade blood flow in ipsilateral ICA in all 16 patients, which was supplied by retrograde blood flow in ipsilateral ECA through carotid bifurcation. We call this phenomenon “ICA steal”. DSA and CTA discovered four pathways of ICA steal, including 1) ipsilateral vertebral artery – occipital artery – ECA – ICA, 2) ipsilateral thyrocervical trunk or costocervical trunk – ascending cervical artery or deep cervical artery – occipital artery – ECA – ICA, 3) contralateral ECA – contralateral superior thyroid artery – ipsilateral superior thyroid artery – ipsilateral ECA – ICA, and 4) ipsilateral thyrocervical trunk – inferior thyroid artery – superior thyroid artery – ECA – ICA. Conclusions: ICA is possible to be patent and supplied by several collateral circulation pathways after CCAO.

Microsurgical Technique for Treatment of Perimedullary Spinal Arteriovenous Fistulae: 2-Dimensional Operative Video

The case is of a 49-yr-old female admitted after acute onset lower cervical/upper thoracic region pain with left hemi-body hypoesthesia below the C7 level. Magnetic resonance imaging showed a spinal cord intraparenchymal hemorrhage at the C6/7 levels. Physical exam revealed hypoesthesia on the left from C7 and below with associated 3/5 wrist and finger extensor and 4/5 triceps strength on the left. The remainder of the neurological exam was normal including lower extremity strength and bowel/bladder function. A craniocervical angiogram showed a perimedullary arteriovenous fistula on the left, ventrolateral aspect of the spinal cord with a single feeding artery that originated from the thyrocervical trunk and entered through the left C6 nerve root sleeve. Venous drainage was cephalad to cortical cerebellar veins and to the suboccipital plexus. A branch of the thyrocervical trunk supplying the ventral spinal cord originated close to the fistula, which precluded endovascular embolization. The patient underwent C6-T1 laminectomies for microsurgical treatment of the fistula. This case demonstrates multiple key concepts in the surgical management of these rare lesions as follows: the ventral aspect of the cervical spinal cord can be safely approached from posterior. The venous anatomy is often confusing and intraoperative angiography utilizing both indocyanine green and conventional digital subtraction techniques are of paramount importance. Unlike arteriovenous malformations, the venous drainage can be pruned to gain visualization and trace the venous anatomy retrograde to the point of the fistula. The patient awoke from surgery at her neurological baseline. The patient consented to de-identified publication of this case.

Four collateral circulation pathways were observed after common carotid artery occlusion

Background: Common carotid artery (CCA) occlusion (CCAO) is a rare condition. Owing to collateral circulation, ipsilateral internal carotid artery (ICA) and external carotid artery (ECA) are often patent. Methods: This study included 16 patients with unilateral CCAO and patent ipsilateral ICA and ECA. The pathways which supplied ICA were investigated by digital subtraction angiography (DSA), transcranial Doppler (TCD), magnetic resonance angiography (MRA) and computed tomography angiography (CTA). Results: In all 16 patients, TCD found antegrade blood flow in ipsilateral ICA in all 16 patients, which was supplied by retrograde blood flow in ipsilateral ECA through carotid bifurcation. We call this phenomenon “ICA steal”. DSA and CTA discovered four pathways of ICA steal, including 1) ipsilateral vertebral artery – occipital artery – ECA – ICA, 2) ipsilateral thyrocervical trunk or costocervical trunk – ascending cervical artery or deep cervical artery – occipital artery – ECA – ICA, 3) contralateral ECA – contralateral superior thyroid artery – ipsilateral superior thyroid artery – ipsilateral ECA – ICA, and 4) ipsilateral thyrocervical trunk – inferior thyroid artery – superior thyroid artery – ECA – ICA. Conclusions: ICA is possible to be patent and supplied by several collateral circulation pathways after CCAO.