Topographical anatomy of cricothyroid membrane and its relation with invasive airway access.
Cricothyroidotomy is a surgical procedure involving penetration through the skin and cricothyroid membrane to maintain airway patency during life-threatening emergency conditions. Complications such as bleeding and laryngeal stenosis can result from it. Our aim in this study was to identify the anatomical structures located on the membrane and to ascertain whether there is a safe area on the membrane for this procedure. Thirty larynx specimens fixed with 10% formaldehyde in the Department of Anatomy were dissected. The cricothyroid artery, the cricothyroid vein, the common artery and vein formed by the cricothyroid vessels, the pyramidal lobe of the thyroid gland and lymph nodes were observed on the membrane. The cricothyroid membrane was divided into four quadrants and the most common locations of these anatomical structures on the membrane were recorded. The cricothyroid artery and vein were located on the upper half of the membrane, the common vein was found in the midline, coursing to the thyroid gland, and the lobus pyramidalis and lymph nodes were located on the left side of the midline. Overall, the anatomical structures were mostly located on the upper half and lower left quadrant of the cricothyroid membrane. Thus, the lower right quadrant seems safer for invasive procedures such as needle cricothyroidotomy or other cannulation techniques. Needle puncture or cannulation through the lower right quadrant of the cricothyroid membrane will injure fewer anatomical structures so there should be fewer complications due to degradation of the vascular supply to this region. Clin. Anat. 29:949-954, 2016. © 2016 Wiley Periodicals, Inc.