A 54-year-old man comes to the office due to several months of heartburn, acid regurgitation, and dysphagia. He has taken antacids and over-the-counter medications without relief. Medical history includes hypertension and hyperlipidemia. The patient does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits. BMI is 32 kg/m². Physical examination is unremarkable. Upright chest x-ray shows an opacity with an air-fluid level behind the heart. A subsequent barium swallow reveals the proximal stomach herniating through the esophageal hiatus. Which of the following pathophysiological changes most likely contributed to this patient's current condition?

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Quizplus · Accepted Answer

11ec160b_3584_0aa3_9249_c9adcfd9a07b_MD0001_00 This patient has a hiatal hernia, a common disorder in which the contents of the abdominal cavity herniate through the diaphragm into the thoracic cavity at the esophageal hiatus. The distal esophagus is normally attached circumferentially to the diaphragm by the phrenoesophageal membrane at the gastroesophageal (GE) junction; disruptions in membrane integrity can result in hernia formation: Sliding hiatal hernias are the most common form and occur due to laxity of the phrenoesophageal membrane, which typically results from repetitive stress on the membrane (eg, coughing, vomiting). This allows the GE junction and proximal stomach to slide upward into the thoracic cavity and predisposes patients to reflux symptoms (eg, heartburn, regurgitation, epigastric/chest pain) due to incompetence of the lower esophageal sphincter. Paraesophageal hernias are rarer and occur due to a defect (hole) in the phrenoesophageal membrane. Laxity of the gastrocolic and gastrosplenic ligaments (which anchor the stomach in the abdomen) allows the gastric fundus to migrate into the thoracic cavity. Larger defects can also result in the subsequent herniation of the GE junction and surrounding structures (eg, bowel, spleen) into the chest. This predisposes patients to gastric volvulus, ulcerations, and respiratory complications (due to lung compression). (Choice A) Barrett esophagus is the metaplastic replacement of normal squamous cells in the distal esophagus with squamocolumnar cells and occurs as a result of chronic acid reflux. Patients with Barrett esophagus are at increased risk of esophageal cancer, but it does not cause herniation. (Choice C) Diaphragmatic muscle paralysis due to C3-5 motor nerve injury causes an elevated hemidiaphragm. Patients are typically asymptomatic (due to compensation by the other respiratory muscles), but dyspnea or orthopnea can occur. It is not associated with herniation of intrabdominal contents into the chest. (Choice D) Failure of the posterolateral diaphragmatic foramina to fuse can cause a Bochdalek hernia. This congenital hernia is typically diagnosed pre- or perinatally; pulmonary hypoplasia with neonatal respiratory distress is common. (Choice E) Herniation of the viscera through the omental foramen (foramen of Winslow) causes an intraabdominal hernia known as lesser sac hernia. Lesser sac hernias are very rare, typically involve the small bowel, and cause severe abdominal pain due to bowel strangulation or obstruction. Educational objective: Hiatal hernias occur when contents of the abdominal cavity herniate through the diaphragm at the esophageal hiatus into the thoracic cavity. Sliding hiatal hernias occur due to laxity of the phrenoesophageal membrane, leading to herniation of the gastroesophageal junction and proximal stomach, whereas paraesophageal hernias occur due to defects in the membrane, resulting in the gastric fundus herniation.

A 54-Year-Old Man Comes to the Office Due to Several