What Is the Cricoid Cartilage?

Laryngeal cartilage, under the thyroid cartilage, forms the base of the larynx. It is shaped like a ring, with a narrow front and a ring-shaped cartilage arch, and a high and wide rear with a ring-shaped cartilage plate. The back of the arch is flat to the 6th cervical vertebra, which is an important surface marker of the neck. The upper edge of the plate has a pair of small articular surfaces connected to the sacral cartilage; the two sides of the junction of the plate and the arch are related to the inferior thyroid cartilage. The lower edge of the annular cartilage is connected to the trachea. Circular cartilage is the only complete cartilage ring in the airway cartilage scaffold, which plays an important role in supporting the opening of the airway. Such injuries may cause throat stenosis.

Laryngeal cartilage, under the thyroid cartilage, forms the base of the larynx. It is shaped like a ring, with a narrow front and a ring-shaped cartilage arch, and a high and wide rear with a ring-shaped cartilage plate. The back of the arch is flat to the 6th cervical vertebra, which is an important surface marker of the neck. The upper edge of the plate has a pair of small articular surfaces connected to the sacral cartilage; the two sides of the junction of the plate and the arch are related to the inferior thyroid cartilage. The lower edge of the annular cartilage is connected to the trachea. Circular cartilage is the only complete cartilage ring in the airway cartilage scaffold, which plays an important role in supporting the opening of the airway. Such injuries may cause throat stenosis.

Chinese name

Circular cartilage

Foreign name

cricoid cartilage

lie in

Pharyngeal

important meaning

Maintain throat shape

Anatomical structure of circular cartilage and its application

1. The generalized cyclomembrane is located between the circular cartilage and the thyroid cartilage, and is a conical elastic fibrous connective tissue membrane. The narrowly defined crustaceous membrane refers only to the front part of the elastic cone. Its upper boundary is the lower edge of the thyroid cartilage, the lower boundary is the upper edge of the circular cartilage, and the two sides are the medial edge of the circular nail.

2. The anterior surface of the crustaceous membrane is the skin and subcutaneous tissue. The blood vessels are only from the cerebellar arteries originating from the superior thyroid artery. There are often small anastomotic branches (caudal arterial arches) running from both sides between the left and right cerebellar arteries. The perforating branch is issued and enters the larynx from the upper part of the cyclomembrane.

3. The nerve is only the outer branch of the superior laryngeal nerve issued by the vagus nerve, and it accompanies the superior thyroid artery and the circular nail arteries. The posterior part of the cyclomembrane is the subglottic cavity of the larynx, and the posterior wall is a circular cartilage plate.

4. Application: Due to the superficial position of the cyclomembrane, there are no important blood vessels, nerves and special tissue structures, and it is not calcified for life, so it is the most convenient and safe part for puncture or incision. The part of the ciliary membrane that thickens on the anterior median line (that is, the part connected between the circular cartilage arch and the anterior horn of the thyroid cartilage) is called the ciliary median ligament, and the cerebrocentesis puncture and incision are performed here. Cyclotroniocentesis or incision is a first-aid technique commonly used in various clinical departments. When upper airway obstruction, especially laryngeal obstruction, is too late or unconditional to perform tracheal intubation and tracheotomy, it is necessary to perform a cyclomembrane puncture. Or incision can temporarily establish artificial airways, give oxygen or inject topical anesthetics and other therapeutic drugs.

Tissue structure and significance of circular cartilage

Applicable anatomy of the ciliary ligament and its clinical significance. Cycleotomy is suitable for patients with respiratory and sputum dysfunction caused by various reasons. It can relieve pain when the laryngeal fissure is performed or the vertical half-throat is performed. At present, the understanding of the anatomy and variation of the small duodenal papilla is still insufficient, and the existing anatomical data are far from meeting the clinical needs, so that endoscopic duodenal papilla intubation and incision are performed. Have a low success rate.

Clinical application of circular cartilage

1. A large number of anatomical and physiological studies of the larynx have shown that the most basic structure of the vocal function of the larynx is not the vocal cord previously considered, but the ring-shaped unit (sacral cartilage, complete ring-shaped sacroiliac joints, ring-shaped hips, posterior ring-shaped muscles, Superior laryngeal and recurrent laryngeal nerves). Partial laryngeal cartilage resection for laryngeal function is based on this concept. Therefore, circular cartilage partial laryngectomy is a type of functionally-preserving laryngectomy. Its purpose is to completely remove the malignant tumor of the larynx while retaining the vocal, respiratory, and swallowing functions of the larynx without the need for a permanent tracheostomy.

2. According to the tumor site, resection range and reconstruction method, partial resection of the upper cartilage can be divided into ring cartilage hyoid epiglottic fixation and ring cartilage hyoid fixation. CHEP is a surgical treatment for glottic laryngeal cancer. The vocal cords, ventricles, paraglottic space, and the entire thyroid cartilage are removed on both sides of the epithelium, hyoid bone, ring cartilage, and at least one iliac cartilage (with innervated ring unit), the reconstruction of the larynx is to fix and suture the circular cartilage, hyoid bone, and epiglottis, so it is called circular cartilage hyoid epiglottis or SCPL-CHEP. CHP is an operation for supraglottic laryngeal cancer. In addition to the scope of CHEP resection, the epiglottis and anterior space of the epiglottis are resected together. The reconstruction method is to fix and suture the circular cartilage and hyoid bone, so it is called circular cartilage tongue. Osteotomy or SCPL-CHP.

3. The indications for A.CHEPSCPL-CHEP are: T1b glottic laryngeal cancer: bilateral vocal cord cancer; T2 glottic laryngeal cancer: upward invasion to the laryngeal ventricle, ventricular zone, and anterior commissure, but not involving the epiglottic root and The anterior space of the epiglottis, which invades the lower part of the subglottic anterior midline and does not exceed 1 cm, and the posterior part does not exceed 0.5 cm; part of the selected T3 glottic laryngeal cancer: such as glottic laryngeal cancer with fixed vocal cord on one side, the tumor range is not Exceed the indication. The contraindications of SCPL-CHEP are: the tumor invades the subglottic area more than 1cm in the front and the back more than 0.5cm; bilateral sacral cartilage and sacral space are involved; the epiglottis anterior space or above the root of the epiglottis; Circular cartilage was invaded; The perichondria outside the thyroid cartilage was invaded, and the tumor invaded the throat.

The indications for B.CHPSCPL-CHP are: supraglottic laryngeal cancer involves epiglottis, ventricular zone, and sacral cartilage below the level of the hyoid bone, resulting in limited vocal cord activity on one side; supraglottic cancer Anterior commissure, one or both vocal folds, one vocal fold activity is limited, but at least one 1/3 of the vocal folds are normal and vocal fold activity is good; glottic, supraglottic, and transglottic cancer appear The vocal cords on one side were significantly restricted or fixed, but the subglottic area invaded the anterior middle part was less than 1 cm, and the ring cartilage and the condylar cartilage on the other side were still retained. The contraindications of SCPL-CHP are: subglottic invasion reaches the upper edge of ring-shaped cartilage or even ring-shaped cartilage damage; the anterior epiglottic space is obviously invaded, clinically showing the epigastric submucosal bulge or lesion has broken through the thyroid hyoid periosteum; the tumor is adjacent to the tongue Those who need to remove the hyoid bones; The destruction of the adventitia of the thyroid cartilage and the tumor invasion outside the throat.

C. Partial laryngeal cartilage resection is based on the complete removal of laryngeal tumors. By retaining some basic structures of the throat, at least one mobile ring-shaped unit and ring cartilage are retained, so that the patient can retain vocal, breathing and swallowing functions. Without the need for a permanent tube, it can improve the quality of life of patients.