Branch Of Superior Thyroid Artery Research Articles

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

BackgroundPrevious 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.MethodsIt 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.ResultsOut 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.ConclusionBased 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.

Paramedian Ectopic Thyroid Gland and Unusual Origin of Superior Thyroid Artery-A Case Report and Review of Literature

Ectopic thyroid is considered as one of the developmental anomalies of the thyroid gland. It is usually found in the midline, along the line of descent of thyroid diverticulum. Ectopic thyroid is very rarely found in the lateral part of the neck. During the routine dissection classes for undergraduate medical students, we came across the presence of a laterally placed ectopic thyroid gland. An oval-shaped mass of thyroid tissue was situated on the left side of the neck. It was located superficial to the inferior constrictor muscle, close to its origin from the oblique line of the thyroid cartilage. It was supplied by a branch of superior thyroid artery. Superior thyroid artery arose from the common carotid artery just before its bifurcation into external and internal carotid arteries.

Loupe Assisted Thyroidectomy: Prevention of Complications is better than Treating Them

Aim: Studying the value of the surgical loupe in the enhancement of performing safe thyroidectomy via dissection of the major structures which are vulnerable to injury during the operation. Subjects and methods: 150 patients with benign and malignant thyroid masses underwent near total or total thyroidectomy at Zagazig university hospitals. History taking and all necessary investigations were done. Thyroidectomy was done under the magnification of the surgical loupe and we dissected the recurrent laryngeal nerve, the external branch of superior laryngeal nerve, branches of superior thyroid artery and selectively ligating them and trace the parathyroid glands by following their minute blood vessels originating from the inferior thyroid artery. Results: Mean age of the patients was 42.5 years (range: 23-69). Female: male ratio was 19:11 (95/55). 65 patients (43.3%) had a discrete thyroid nodule and 85 patients (56.7%) had multinodular goiter. Patients were sent home in a mean of 1.6 days (1–4 days). No operative related mortality was encountered. Only three cases of transient hypocalcaemia which were resolved within three days by oral calcium supplementation and symptoms did not recur during the follow-up of these three patients. All patients were extubated without any complications. There was no any case recorded for hoarseness of voice or low pitched voice. There was only one case of secondary hemorrhage and was re-explored for control of the source (injured anterior jugular vein on the right side). Three cases developed hypertrophic scars during the follow up. Conclusion: total or near total thyroidectomy can be done with a minimal number of complications by using the surgical loupe during the dissection of the recurrent laryngeal nerve, the external branch of the superior laryngeal nerve and the parathyroid glands and their minute blood vessels.

Analysis of the arterial anatomical variations of thyroid gland: anatomic guide for surgical neck dissection

Aim of this study was to establish preliminary data on the variations of arterial supply of thyroid gland in Karnataka population. The anterior triangles in the neck of formalin fixed cadavers were dissected. The length, branching pattern, number and length of branches of superior thyroid artery (STA) were noted. We measured the length of inferior thyroid artery (ITA) from its point of emergence from thyrocervical trunk (TCT) to lower pole of thyroid gland. The length of the external carotid artery (ECA), TCT from the point of its emergence to the point of its branching was noted. We noted the number of branches from ITA and TCT. Presence of any additional artery supplying the thyroid gland was searched for. Difference in the length of STA and ITA between the two sexes and sides were noted. Statistical analysis was done by Student's t-test. In our study the maximum length of STA was 5.34cm and that of ITA was 5.07cm and there were no statistically significant side-to-side differences in level of bifurcation. Observations of the present study on the course and branching pattern of arteries around thyroid gland will help in easier approach during thyroid surgeries and interventional techniques (Tab. 1, Fig. 3, Ref. 38).

Moxonidine acting centrally inhibits airway reflex responses.

We examined the role of I1-imidazoline (I1-IR) receptors in control of airway function, by testing the effects of systemic administration of the I1-IR agonist moxonidine on reflex responses of tracheal smooth muscle (TSM) tone to either lung deflation or mechanical stimulation of intrapulmonary rapidly adapting receptors. Experiments were performed in either alpha-chloralose anesthetized or decorticate, paralyzed, and mechanically ventilated beagle dogs. Moxonidine (10-100 micrograms/kg) administered via three different routes (femoral vein, muscular branch of superior thyroid artery, and vertebral artery) attenuated TSM responses to stimulation of airway sensory nerve fibers by two different ways and caused a decrease in arterial pressure and heart rate. These effects were dose dependent and were significantly reversed by efaroxan (an I1-IR and alpha 2-adrenergic blocker) administered via the vertebral artery. Intravertebral efaroxan abolished the hemodynamic effects of moxonidine. Intravenous moxonidine (10-100 micrograms/kg) did not alter airway smooth muscle responses to electrical stimulation of the peripheral vagus nerve. In addition, in vitro moxonidine (1-100 micrograms/ml) had no effect on contractile responses to increasing doses of acetylcholine. These findings indicate that moxonidine may act at a central site to suppress reflex airway constriction, even when given into the systemic circulation. Given the presence of I1-IR sites and alpha 2-adrenergic receptors in brain regions participating in airway reflexes, these receptor classes may be involved in brainstem control of the cholinergic outflow to the airways.

I 1-imidazoline receptors and cholinergic outflow to the airways

We examined the role of I 1-imidazoline receptors in the control of airway function, by testing the effects of systemic administration of the I 1-imidazoline agonist moxonidine on reflex responses of tracheal smooth muscle (TSM) tone to either lung deflation or mechanical stimulation of intrapulmonary rapidly adapting receptors. Experiments were performed in either α-chloralose anaesthetized or decorticate, paralyzed and mechanically ventilated beagle dogs. Moxonidine (10–100 μg/kg) administered via three different routes (the femoral vein, muscular branch of superior thyroid artery, and vertebral artery) attenuated TSM responses to stimulation of airway sensory nerve fibers by two different ways, and caused a decrease in arterial pressure and heart rate. These effects were dose-dependent, and were significantly reversed by efaroxan (an I 1-imidazoline and α 2-adrenergic blocker) administered via the vertebral artery. Intravertebral efaroxan abolished the hemodynamic effects of moxonidine. Intravenous moxonidine (10–100 μg/kg) did not alter airway smooth muscle responses to electrical stimulation of the peripheral vagus nerve. In addition, in vitro moxonidine (1–100 μg/ml) had no effect on contractile responses to increasing doses of acetylcholine. These findings indicate that moxonidine may act at a central site to suppress reflex airway constriction, even when given into the systemic circulation. Given the presence of I 1-imidazoline sites and α 2-adrenergic receptors in brain regions participating in airway reflexes, these receptor classes may be involved in brainstem control of the cholinergic outflow to the airways.