In the laryngeal cavity, there is a congenital membrane-like structure called congenital laryngeal web, which can occupy a large part of the laryngeal cavity and is referred to as a laryngeal septum. Its occurrence is related to abnormal embryonic development. When the embryo reaches 30 mm, the occluded epithelium between the primitive glottis begins to be absorbed, and the duct is reestablished. If the absorption is incomplete, a congenital laryngeal web can form at the glottis. The thickness of the laryngeal web varies, consisting of connective tissue with a few capillaries and covered by the laryngeal mucosal epithelial layer. Laryngeal webs are classified into three types: supraglottic, glottic, and subglottic, with the glottic type being the most common, while those occurring in the supraglottic, subglottic, and posterior laryngeal regions are extremely rare.

bubble_chart Clinical Manifestations

The symptoms of laryngeal webs in infants and young children differ from those in children or adults, and the symptoms also vary depending on the size of the web. Infants with larger webs may exhibit no crying after birth, difficulty breathing or suffocation, a snoring-like laryngeal sound, laryngeal obstruction during inhalation, and often symptoms such as cyanosis of the lips and inability to suckle. In cases of moderate-sized webs, the laryngeal cavity may still allow airflow, but the child may have a hoarse voice accompanied by inspiratory dyspnea. Smaller webs may result in a weak, hoarse cry without significant breathing difficulties. In adults and children, laryngeal webs generally cause no obvious symptoms, occasionally leading to hoarseness or fatigue during speech, and a sensation of breathing difficulty during strenuous activities.

Newborns and infants must be diagnosed using direct laryngoscopy. Laryngeal webs in children or adults can be diagnosed through indirect laryngoscopy or fiberoptic laryngoscopy. Under laryngoscopy, a membrane-like web or septum can be seen in the laryngeal cavity, appearing white or pale red, with a neat posterior edge, mostly arc-shaped, and a few triangular in shape. During inhalation, the web flattens, but when crying or phonating with the glottis closed, the web either retracts downward or protrudes upward like a glottic mass.

Congenital laryngeal webs in infants and young children should be differentiated from other congenital laryngeal abnormalities, such as congenital subglottic obstruction and congenital laryngeal stridor. For children or adults, it is also necessary to determine whether the laryngeal web is congenital or acquired based on medical history. Patients with congenital laryngeal webs often have congenital abnormalities in other areas, which should be noted during diagnosis.

bubble_chart Treatment Measures

When a newborn with laryngeal web experiences asphyxia, a rigid infant bronchoscope should be immediately inserted into the trachea under direct laryngoscopy to suction secretions, provide oxygen, and administer artificial respiration. The treatment outcome is often excellent because the laryngeal web tissue has not yet fully fibrosed, and recurrence is rare after bronchoscopic dilation. For patients with dyspnea or hoarseness, the web membrane should be removed under direct laryngoscopy using a laryngeal knife or electrocautery. However, postoperative dilation is often required to prevent recurrence. In recent years, laser excision of the laryngeal web under microlaryngoscopy has been widely adopted, eliminating the need for postoperative laryngeal dilation with favorable results. Small laryngeal webs without significant symptoms may not require treatment.