Gastro 41 Esophagus - Achalasia

• Primary disorders -
• Achalasia,
• Diffuse esophageal spasm (DES)
• Nutcracker (jackhammer) esophagus,
• Hypertensive lower esophageal sphincter (LES),
• Ineffective esophageal motility (IEM)

• Secondary conditions result from progressive damage induced by an underlying collagen vascular or neuromuscular disorder
• Scleroderma,
• Dermatomyositis,
• Polymyositis,
• Lupus erythematosus,
• Chagas disease, and
• Myasthenia gravis

Achalasia is the motility disorder that results from progressive degeneration of ganglion cells in the myenteric plexus in the esophageal wall, leading to failure of relaxation of the lower esophageal sphincter, accompanied by a loss of peristalsis in the distal esophagus.

• Idiopathic
• Infectious neurogenic degeneration
• Severe emotional stress,
• Trauma
• Drastic weight reduction and
• Chagas disease (parasitic infection with Trypanosoma cruzi)

• Primary pathology - Destruction of the nerves to the LES 
• Secondary pathology - Degeneration of the neuro muscular function of the body of the esophagus

Type I achalasia (classic) - Median IRP >15 mm Hg; 100% failed peristalsis (DCI <100 mm Hg•s •cm); premature contractions with DCI <450 mm Hg•s •cm satisfy criteria for failed peristalsis

Type II achalasia (with esophageal compression) - Median IRP >15 mm Hg; 100% failed peristalsis, panesophageal pressurization with ≥20% of swallows

Type III achalasia (spastic achalasia) - Median IRP >15 mm Hg; no normal peristalsis, spastic contractions with DCI >450 mm Hg•s •cm with ≥20% of swallows

• (Integrated relaxation pressure (IRP), 
• Distal contractile integral (DCI) is the amplitude × duration × length (mm Hg•s •cm))

• Achalasia is a premalignant condition of the esophagus.
• 8% chance of developing carcinoma.
• Squamous cell carcinoma is the most common type identified  due to the result of long-standing air-fluid levels in the body of the esophagus, causing mucosal irritation and inducing metaplasia.
• Adenocarcinoma tends to appear in the middle third of the esophagus, below the air-fluid level where the mucosal irritation is the greatest.

Classic triad - dysphagia, regurgitation, and weight loss.

• Dysphagia Of Achalasia - Begins with liquids and progresses to solids.
• Long standing achalasia may result in regurgitation of undigested, foul-smelling foods.
• Progressive disease may lead to  aspiration Pneumonia, lung abscess, and bronchiectasis
• Heartburn
• Postprandial choking
• Nocturnal coughing.

• Barium Esophagram
• Motility Study
• Endoscopy

• ●Dilation of the esophagus. In patients with late- or end-stage achalasia the esophagus may appear significantly dilated (megaesophagus), angulated, and tortuous, giving it a sigmoid shape.
• ●Narrow EGJ with "bird-beak" appearance caused by the persistently contracted LES.
• ●Aperistalsis.
• ●Delayed emptying of barium
• ●Lack of a gastric air bubble is a common finding on the upright portion of the esophagram

Manometry is the gold standard test for diagnosis. 

Five classic findings, two abnormalities of the LES and three of the esophageal body.

• 1. The LES will be hypertensive, with pressures usually > 35 mm Hg (IRP>15mmHg). 
• 2. Fail to relax with deglutition

• 3. Body of the esophagus will have a pressure above baseline from incomplete air evacuation
• 4. Simultaneous mirrored contractions with no evidence of progressive peristalsis
• 5. Low-amplitude waveforms indicating a lack of muscular tone

ETo evaluate the mucosa for evidence of esophagitis or cancer. It otherwise contributes little to the diagnosis of achalasia

Medical treatment - sublingual nitroglycerin, nitrates, or calcium channel blockers

• Endoscopic intervention - 
• 1. Pneumatic Dilations (Perforation rate < 4%, multiple interventions required)
• 2. Injection Of Botulinum toxin (Botox) directly into LES blocks Ach release, prevents smooth muscle contraction

• 1. Esophagomyotomy (modified Laparoscopic Heller myotomy)
• - It is the operation of choice.
• - Patients will experience some amount of reflux, so additional partial antireflux procedure is done (Toupet or Dor fundoplication)

• 2. POEM (Per oral endoscopic myotomy)
• -  With use of an operating endoscope, the mucosa of the esophagus is dividedaround the mid to distal third, and a submucosal tunnel is created.Through this tunnel, the muscular layer of the distal esophagus,LES, and cardia is visualized and divided performing an endoscopic myotomy.
• - Lack of reflux procedures

• 3. Esophagectomy 
• - Indication - tortuous esophagus (megaesophagus), sigmoid esophagus, failureof more than one myotomy, or reflux stricture that is not amenable to dilation
• - A transhiatal esophagectomy with or without preservation of the vagus nerve offers a good long-term result
• - Esophageal resection also eliminates the risk for carcinoma.

Toupet fundoplication - posterior partial wrap of 180 to 270 degrees, with additional tacking sutures to fix the stomach to the crura in the abdomen

Dor fundoplication is most commonly used in the setting of esophageal myotomy but consists of an anterior 180-degree wrap.

Partial or near Nissen - wrap of 300 or 320 degrees

LINX can be used in patients with minimal or no hiatal hernia. It is a series of magnetic beads that are placed around the EGJ that will stretch with slight pressure in the esophagus, there by mimicking the natural LES.

Type I - GEJ migrates cephalad into the posterior mediastinum.

Type II - GEJ is anchored in the abdomen, and the gastric fundus migrates into the mediastinum through the hiatal defect.

Type III hernia - characterized by both the GEJ and fundus located in the mediastinum.

Type IV - visceral structure (e.g., colon, spleen, pancreas, or small bowel) migrates cephalad to the esophageal hiatus and is located in the mediastinum.

Hiatal hernia types II to IV, also referred to as Paraesophageal hernia.

Gastroesophageal obstructive symptoms, including dysphagia, odynophagia, and early satiety.

Intermittent epigastric and chest pain can develop secondary to visceral torsion and distention, which leads to ischemia of the hernia contents.

Gastrointestinal bleeding can result from mucosal ischemia or mechanical ulceration of the gastric mucosa.

Respiratory symptoms, primarily shortness of breath, can be explained by the mass effect of the hernia contents in the chest.

Heartburn and regurgitation are also reported by patients with PEH.

Regardless of the operative approach, there are four key steps to PEH repair:

• (1) reduction of the hernia contents to the abdominal cavity;
• (2) complete excision of the hernia sac from the posterior mediastinum;
• (3) mobilization of the distal esophagus to achieve a minimum of 3 cm of intraabdominal esophageal length; and
• (4) an antireflux operation.

Boerhaave syndrome is a transmural perforation of the esophagus. 

• Clinical features -
• - Epigastric or chest pain, neck or throat pain, and dysphagia.
• - Physical examination findings might include crepitus on the chest, neck, or face; neck swelling; epigastric tenderness; nasal voice; or sometimes normal examination findings.

• Investigations -
• - Chest radiograph with mediastinal or cervical air, free abdominal air, or pleural effusion.
• - A CT scan may show mediastinal air and periesophageal air or fluid.
• - Barium esophagram is the standard for diagnosis, but CT scan with oral administration of contrast material.
• - If the results of these studies are normal but the level of suspicion is high, patients may require evaluation by direct laryngoscopy or endoscopy, depending on the clinical circumstance.

Management - The principles of management after diagnosis include

(1) treatment of contamination - with broad-spectrum antibiotics, including antifungals

• (2) wide local drainage - 
• - Chest tubes
• - Radiologically guided drains can be used as well.
• - Video-assisted thoracoscopic surgery or open thoracic washout with decortication

• (3) source control
• - Endoluminal therapy with covered stents
• - Surgical control - gold standard. In general, high perforations are approached through a left-sided neck incision, mid esophageal through a right thoracotomy, and distal esophageal through a left thoracotomy or laparotomy.
• - Myotomy to expose the injury, débridement of devitalized tissues, assessment of extent of injury, and considerations for repair.
• - Any sign of obstruction (achalasia, stricture, tumor) must be remedied at the time of the initial operation, else the perforation will not heal.
• - Small injuries with healthy tissues can be repaired primarily in two layers with tissue flap coverage (intercostal muscle, pericardial fat, pleura, omentum), but extensive injuries with devitalized areas can be managed with controlled fistulization by T-tube.
• - Very large or devitalized defects will require esophageal exclusion with creation of a cervical esophagostomy and gastrostomy tube, with plans for future reconstruction by esophagectomy with gastric, colon, or small bowel conduit

(4) enteral feeding access - . Gastrostomy and jejunostomy tubes at the first operation can provide decompression and drainage near the perforation as well as enteral access for nutrition.