There is no venous plexus over the CTM. https://medical-dictionary.thefreedictionary.com/Istmus. The stenotic segment is elevated from the esophagus in a superior direction. Based on clinical and anatomic review, the central lymphatics are generally considered the primary drainage pathways for thyroid cancers, with the lateral neck nodes being considered secondary levels of lymphatic spread. Pneumothorax is an uncommon complication and usually results from a difficult trachea or one with excessive lateral dissection, particularly in children. Illustrated anatomical parts with images from e-Anatomy and descriptions of anatomical structures . However, its dimensions and location can vary. The thyroid is a shield-shaped gland that consists of right and left lobes connected by the isthmus in midline, although occasionally, the isthmus can be absent. Thyroid isthmus Anatomy. As described by Grillo,105 the patient is positioned with the head in extension with a rolled sheet or an inflatable bag under the shoulders for the resection. If more than 4 cm of trachea is resected, it is prudent to perform a laryngeal release procedure.103 A laryngeal release consists of one of two maneuvers. The trachea is usually entered between the second and third (or third and fourth) tracheal rings; in children, one ring often must be divided. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9781416029519500517, URL: https://www.sciencedirect.com/science/article/pii/B9781437722079000239, URL: https://www.sciencedirect.com/science/article/pii/B9780323040488500190, URL: https://www.sciencedirect.com/science/article/pii/B9781437722321000358, URL: https://www.sciencedirect.com/science/article/pii/B9781416058977000184, URL: https://www.sciencedirect.com/science/article/pii/B9781416025276000347, URL: https://www.sciencedirect.com/science/article/pii/B9780702033728000070, URL: https://www.sciencedirect.com/science/article/pii/B9781437727647000312, URL: https://www.sciencedirect.com/science/article/pii/B9780128012383957714, URL: https://www.sciencedirect.com/science/article/pii/B9781416042204500389, Michael McLeod MD, Gerard M. Doherty MD, in, Evidence-Based Physical Diagnosis (Third Edition), The Delphian node, a lymph node that drains the thyroid gland and larynx, lies directly anterior to the cricothyroid ligament (just cephalad to the, Pediatric Respiratory Medicine (Second Edition), Tracheotomy is a surgical procedure; details of technique may be found in standard surgical texts. The tracheal tube can sometimes follow a false passage anterior or lateral to the trachea. The thyroid gland lies within the visceral space of the infrahyoid neck, wrapping around the upper trachea. The thyroid isthmus lies about halfway between the thyroid cartilage (the Adam's apple) and the sternal notch. The thyroid isthmus is then divided, and the gland is elevated off of the anterior wall of the trachea. It lies in a position anterior to the trachea. The thyroid isthmus is anterior to the trachea, usually overlying the first through the third tracheal rings. Extraglandular lymphatics generally follow venous flow; the inferior portions of the lateral lobes drain along the tracheoesophageal groove into the central neck. 23-4). The superior tracheal rings are retracted laterally, with heavy sutures placed in the mid-lateral tracheal line at a point one to two rings above the intended line of tracheal division. The classic operation for primary hyperparathyroidism is a bilateral neck exploration with identification of all parathyroid tissue followed by the removal of any abnormal glands. New York, NY: Churchill Livingstone; 1995. We use cookies to help provide and enhance our service and tailor content and ads. The strap muscles are dissected along the midline and retracted laterally. Michael McLeod MD, Gerard M. Doherty MD, in Surgical Pitfalls, 2009, Induce general anesthesia and secure airway, Transverse incision along skin lines inferior to thyroid isthmus through platymus, raising subplatysmal flaps, Separate strap muscles in midline, exposing thyroid gland, Expose upper pole vessels by dissecting between cricothyroid muscle and thyroid gland and lateral to thyroid gland, Reflect thyroid medially and dissect lateral aspect of gland, Identify inferior thyroid artery, recurrent laryngeal nerves (RLNs), and parathyroid glands in tracheoesophageal groove, Divide inferior thyroid artery branches, thyroid attachment to trachea anterior to RLN insertion, and inferior pole vessels, Divide thyroid isthmus. In cases where the airway is deviated due to infection, mass, or other etiology, the surgeon must be careful to avoid dissecting off course, inferiorly and laterally. The superior trachea is divided above the stenosis (Figure 34-9). 1891-6. When compared to a more focused parathyroidectomy, bilateral neck exploration is associated with longer operative times and higher rates of post-operative hypocalcemia (Bergenfelz et al., 2002).

Damage to the RLN can be either by excessive lateral dissection, thermal injury from cautery, or from retraction injury. It may be difficult to reinsert the tracheostomy tube if it becomes dislodged before healing of the incision and establishment of a mature stoma, especially if the ends of the cartilage ring that was cut in the operation resume their normal position. For stenosis with a prior tracheotomy, the anterior wall of the trachea just superior to the region of maximal adherence is identified. The anterior border of the sternocleidomastoid muscle is dissected from its attachment to the sternum. The aperture by which the mouth communicates with the pharynx is called the isthmus faucium. It also acts as a covering for the second and the third tracheal rings. http://en.wikipedia.org/wiki/Thyroid_isthmus, http://medical-dictionary.thefreedictionary.com/isthmus+of+thyroid, Last updated on February 4th, 2018 at 11:29 am. If possible, the circumferential dissection is carried up along the lesion itself. Circumferential dissection is performed at the level of the lower border of the lesion. 3rd ed. Paratracheal or pretracheal placement of the tracheal tube can be a significant intraoperative complication if manual control of the airway is not maintained until end-tidal CO2 is confirmed. A Penrose drain is passed around the trachea at the lower end of the resection, where the circumferential dissection has been performed. Lower laryngeal lesions and upper tracheal lesions can be accessed through an anterior transcervical approach. IOPTH levels may be used to confirm adequate resection.