Pharyngeal constrictors surround the pharynx posteriorly and laterally, meeting midline at the posterior raphe. The pharyngeal constrictors are comprised of three circularly oriented muscles, the superior, medial, and inferior constrictors, that function to propel food and water from the oropharynx through the laryngopharynx, and on to the esophagus. Although oriented circularly around the pharynx, constrictors are arranged longitudinally, which aids in maintaining the airway within the pharynx. 

Elevator muscles, which include the palatopharyngeus, stylopharyngeus, and salpingopharyngeus, aid in swallowing by pulling the larynx up behind the base of the tongue, thereby protecting the airway. Elevation of the laryngopharynx also functions in shortening the pharynx during swallowing to improve the passage of food and liquids.[7]

The specific constrictor muscle that is in the vicinity of the laryngopharynx is the inferior constrictor, which is composed of two muscles: the thyropharyngeus and cricopharyngeus. The thyropharyngeus muscle is superior to the cricopharyngeus and lies laterally and posteriorly to the laryngopharynx. Relaxation of the cricopharyngeus and thyropharyngeus allow pharyngeal contents to enter the esophagus.[5]

Laryngopharyngectomy:

Laryngopharyngectomy, complete removal of the larynx and hypopharynx, is generally reserved as salvage therapy following chemoradiation or for patients with advanced cancers of the hypopharynx or larynx. The primary treatment for patients with laryngopharyngeal cancer is radical radiotherapy and/or chemotherapy, as these are organ-preserving treatment modalities.[8][9] If the laryngopharyngectomy is for the treatment of laryngopharyngeal cancer, it is also recommended to dissect the bilateral level II-IV neck lymph nodes. Neck dissection serves two important purposes: (1) Determine the extent of nodal involvement and (2) to access vessels used in free flap reconstruction.[10]

Surgical Fundoplication in Laryngopharyngeal Reflux:

Nissen fundoplication is a surgery classically used in the treatment of gastroesophageal reflux disease (GERD) whereby the upper part of the stomach, known as the fundus, is wrapped around the esophagus to reinforce the lower esophageal sphincter. Some studies have demonstrated success in treating laryngopharyngeal reflux (LPR) with fundoplication in a subset of select patients.[11] Treatment of LPR involves a combination of dietary and lifestyle changes, as well as proton pump inhibitors (PPI). Although 50-70% of patients improve with PPIs, many patients still suffer from laryngeal irritation despite high dose PPI treatment.[12][13] Researchers hypothesize that patients who fail to improve on PPI therapy may benefit from fundoplication under the premise that reinforcement of the lower esophageal sphincter (LES) may prevent low volume reflux of acid or nonacid gastric content.[14] However, a prospective controlled trial demonstrated limited improvement in laryngeal symptoms one year following fundoplication surgery for LPR.[15]

Cancer:

Studies have shown that 72% to 87% of pharyngeal cancers arise in the laryngopharynx, often referred to as hypopharyngeal cancer in the literature.[16][17] The pyriform sinus has the highest proportion of these cancers (78.3%), followed by the posterior pharyngeal wall (14%), and then the post-cricoid area (8%).[16] Cancers of the hypopharynx account for 6% of all cancer of the head and neck, more than 95% of which are squamous cell carcinoma.[18] Other hypopharyngeal cancers include spindle cell carcinoma, salivary gland carcinoma, and basaloid squamous carcinoma.[19]

Hypopharyngeal cancers are dangerous because of their late presentation and predilection for metastasizing, with more than 85% of cancers have spread beyond the laryngopharynx at the time of diagnosis. The most common site of metastasis (65%) is to regional lymph nodes. Cancer of the hypopharynx is a devastating diagnosis, with a 5-year survival rate as low as 29%.[19] The main risk factors are alcohol consumption and smoking, although other environmental exposures such as asbestos, indoor air pollution, and coal dust also have links to hypopharyngeal cancer.[20][21][22]

Hypopharyngeal cancer can present with dysphagia, a prominent neck mass, voice impairment, hoarseness, and/or referred otalgia. Treatment is a complicated multidisciplinary decision that involves collaboration among medical oncologists, radiation oncologists, and head and neck surgeons. It is a highly controversial topic since there is no uniform consensus for the best approach to treatment.[23] Treatment options include radiation, chemotherapy, surgery, or a combination thereof, with surgery being the preferred therapeutic option.[24] The goal of treatment is to obtain local tumor control while simultaneously preserving the function of the many important structures located adjacent to the laryngopharynx, which is involved in speech, swallowing, and respiration. In cases of advanced disease, laryngectomy or laryngopharyngectomy may necessary.

Laryngopharyngeal reflux:

Laryngopharyngeal reflux (LPR) is a highly controversial topic due to a disagreement among otolaryngologists and gastroenterologists regarding its pathophysiology. Otolaryngologists believe that LPR is due to retrograde flow of digestive stomach contents to the laryngopharynx, leading to mucosal injury and irritation.[25] The pathophysiology of GERD is similar in that it is due to the reflux of gastric contents into the esophagus. Interestingly, LPR rarely presents with heartburn (20%) or regurgitation, even though the acid and other corrosive stomach contents must traverse the esophagus to reach the larynx. Gastroenterologists argue that low comorbidity of GERD among patients with LPR signifies that an alternate etiology must exist.

LPR is one of the most common presentations in otolaryngology clinics, with some studies demonstrating as many as 10% of visits due to symptoms secondary to LPR.[26] LPR presents with symptoms of cough, hoarseness, throat clearing, and globus sensation.[25] It is a difficult diagnosis to make due to nonspecific symptoms that mimic many other conditions that affect the larynx, including allergies, vocal abuse, smoking, infections, and alcohol abuse.[27][28] More than half of patients presenting with hoarseness have some form of the reflux-associated disease.[29][30] Complications of LPR include subglottic stenosis, contact ulcers, granulomas, and lower airway disease, among others.[31] Diagnosis is often made based on a careful history.[25] Since LPR is associated with upper aerodigestive tract cancer, a full laryngopharyngeal examination is necessary if LPR is suspected.[32][33]

Documenting response to treatment can be a challenge since there are few objective physical exam findings to determine the extent of disease. Belafsky et al. developed the Reflux Symptom Index, an LPR grading system designed to help clinicians determine the relative effect of treatment in their LPR patients.[34] Another method for evaluating the severity of symptoms and progression of the disease is through acoustic voice analysis, which measures frequency, intensity, signal-to-noise ratio, and perturbation in patients presenting with hoarseness.[29] Regardless, clinicians must often rely on subjective symptoms obtained in history as well as clinical judgment to assess response to treatment.

The first diagnostic test indicated is laryngoscopy, which typically shows nonspecific signs of laryngeal irritation that leads to redness, thickening, and edema confined to the posterior larynx.[28] Diagnosis can be confirmed using three different approaches: endoscopic observation of damaged laryngopharyngeal tissue, pH monitoring studies, or symptomatic response to empiric medical and behavioral therapy.[25]

Treatment of LPR is a combination of behavior modification and medical treatment. Patients are often initially prescribed acid-suppressing medication, such as PPIs, to aid in both treatment and diagnosis of LPR.[35] Other medical therapies include H2 receptor antagonists, mucosal cytoprotectants, and prokinetic agents. Behavior modification includes the avoidance of alcohol, smoking cessation, and weight loss. Patients should also be instructed to avoid dietary triggers such as chocolate, carbonated beverages, citrus fruits, fats, red wines, caffeine, spicy tomato products, and meals before bedtime.[36] If lifestyle changes and medical therapy fail in managing symptoms, patients with significant reflux due to lower esophageal sphincter incompetence can opt for surgical intervention. Although some otolaryngologists advocate for fundoplication, there is limited evidence demonstrating its efficacy in resolving symptoms of LPR.[15]