Oesophagus Lecture 1

Oesophagus Lecture 1

• The oesophagus is a 25cm long muscular tube. It runs from the upper oesophageal sphincter (cricopharyngeus muscle) in the neck to the cardia of the stomach.
• The upper oesophagus is striated muscle, followed by a transitional zone of striated and smooth muscle, with the lower half being entirely smooth muscle.
• The oesophagus is lined with squamous epithelium throughout.
• The parasympathetic nerve supply is by branches of the vagus nerve which connects to the myenteric (Auerbach's) plexus. Meissner's submucosal plexus is sparse in the oesophagus.

Oesophageal Physiology

• The main function is to transport food from the mouth to the stomach.
• Initial movement is voluntary, then the pharyngeal phase is involuntary with sequential contraction of oropharyngeal musculature, closure of nasal and respiratory passages, ceasing breathing, and opening of the upper oesophageal sphincter.
• Swallowing beyond this point is involuntary.
• The oesophageal body propels food through a relaxed lower oesophageal sphincter (LOS). Air is also drawn in.
• Primary peristalsis is the coordinated wave following a conscious swallow. It is under vagal control but has specific neurotransmitters that control the LOS.
• The upper oesophageal sphincter is closed at rest, preventing regurgitation of contents into the respiratory passages.
• The normal LOS is 3-4cm long, and has a pressure of 10-25 mmHg.

Secondary and Tertiary Contractions

• Secondary peristalsis is the normal reflex wave that follows a conscious swallow.
• Tertiary contractions are non-peristaltic, infrequent (<10%) waves during manometry (although they can be detected during a meal).

Symptoms of Oesophageal Disease

• Difficulty swallowing (food or fluid sticking, oesophageal dysphagia): this might indicate malignancy.
• Pain on swallowing (odynophagia): suggests inflammation or ulceration.
• Regurgitation/reflux (heartburn): common in gastro-oesophageal reflux disease.
• Chest pain: hard to distinguish from cardiac pain.

Investigations

• Radiography: Contrast radiography is used to show changes in oesophageal diameter, anatomical distortions, and abnormal motility. It can also detect foreign bodies.
• Computed Tomography (CT): is an essential investigation for neoplasms of the oesophagus, and can replace contrast swallow to detect perforations.
• Endoscopy: Used for most oesophageal conditions, to view the inside, take biopsies or cytology specimens remove foreign bodies, and dilate strictures.
• Endosonography: High-frequency transducer on endoscope tip gives highly detailed images of oesophageal wall layers, and mediastinal structures.
• Oesophageal manometry: Used widely to diagnose oesophageal motility disorders, with comprehensive information about body function and behaviour of the LOS.
• Twenty-four-hour pH and combined pH-impedance recording: Most accurate for gastro-oesophageal reflux. A small pH probe is placed 5cm above the upper margin of the LOS, measured by manometry. Scoring systems are used (e.g. Johnson-DeMeester).

Foreign Bodies

• Food bolus is one of the most common foreign bodies. These often disintegrate and pass, especially after consuming fizzy drinks.
• Flexible endoscopy is usually used to remove foreign bodies.
• Button batteries are a concern inside the oesophagus.

Perforation of the Oesophagus

• Perforation of the oesophagus is typically iatrogenic (from therapeutic endoscopy) or from barotrauma (spontaneous perforation, e.g. Boerhaave's syndrome).
• Boerhaave's syndrome: Vomiting against a closed glottis leads to rapid increasing pressure. It can burst at its weakest point in the lower third, sending material into the mediastinum and sometimes pleural cavity.
• Rapid chemical irritation and infection can follow.
• Misdiagnosis can occur, such as with myocardial infarction, perforated peptic ulcer, or pancreatitis, if pain is limited to the upper abdomen.
• Confirmation is often by chest radiograph (air in mediastinum, pleura, or peritoneum).
• Pleural effusions can follow free communication or reaction to mediastinal inflammation.

Management of Perforation

• Aim of treatment is to limit contamination and prevent infection.
• Decision to undertake surgery or non-surgical management depends on four factors: site of perforation (cervical or thoracoabdominal), cause (spontaneous or instrumental), underlying pathology (benign or malignant), and the state of the oesophagus (fasted, empty, or obstructed).
• Non-surgical management includes hyperalimentation (preferably enteral route), nasogastric suction and broad spectrum intravenous antibiotics.
• Surgical management involves direct repair, intentional external fistula creation, or oesophageal resection (with delayed reconstruction).
• Table 62.1 outlines factors that suggest surgical vs. non-surgical options.

Mallory-Weiss Syndrome

• Forceful vomiting can cause a mucosal tear at the cardia instead of a full perforation.
• The condition typically presents with haematemesis, but bleeding is usually not severe.
• Endoscopic injection therapy might be necessary in severe cases.
• Surgery is rarely needed.

Gastro-oesophageal Reflux Disease (GORD)

• Most reflux episodes occur during postprandial transient LOS relaxations (TLOSRs).
• Initially, GORD can be due to increased number of transient relaxations of the LOS, rather than persistent decrease in pressure.
• Severe GORD is characterised by low LOS pressure, potentially worsened by inadequate length of intra-abdominal oesophagus.
• Sliding hiatus hernia can be associated with GORD and worsen it; however, if the LOS is competent, the pathological GORD doesn't occur.
• Strong GORD-obesity link and rising incidence of oesophageal adenocarcinoma is a clinical concern.

Clinical Features of GORD

• Classic symptoms: retrosternal burning pain (heartburn), epigastric pain (sometimes radiating to the back), and regurgitation.

Diagnosis of GORD

• Often assumed rather than proven; treatment is empirical.
• Investigation is only required in doubt, non-response to PPI or dysphagia.
• Endoscopy with biopsy is the most helpful first investigation.
• Finding reflux oesophagitis, peptic stricture, or Barrett's oesophagus clinches the diagnosis.
• Oesophageal manometry and 24-hour pH recording are gold standards for GORD diagnosis.

Oesophageal Surgery

• Surgery has reduced frequency as medical treatments have improved.
• Management is primarily medical, with PPIs being effective.
• Laparoscopic fundoplication is a frequently used surgical technique. There is surgical creation of an intra-abdominal segment of oesophagus and wrap of stomach around the intra-abdominal oesophagus.
• Risks include low mortality rate but possible concerns of patient selection, failed operation, and side-effects (e.g., dysphagia, abdominal bloating).
• Strictures can arise later.

Barrett's Oesophagus

• Barrett's oesophagus is a metaplastic change of the oesophagus lining in response to chronic gastro-oesophageal reflux (with the squamous-to-columnar junction moving proximally).
• Intestinal metaplasia is a risk factor for adenocarcinoma.
• Treatment focuses on the underlying GORD.
• Regular surveillance endoscopy with multiple biopsies is recommended, to detect dysplasia or cancer early.
• Endoscopic treatments (laser, PDT, argon-beam plasma coagulation, RFA, and EMR) exist for Barrett's mucosa to potentially minimise cancer risk.

This quiz covers the anatomy and physiology of the oesophagus, a critical component of the digestive system. It discusses the structure of the oesophagus, including its muscle composition and nerve supply, as well as its role in the swallowing process. Test your understanding of these essential functions and components.