Syllabus
GASTROINTESTINAL AND ABDOMINAL PROBLEMS
The expanded synopsis of the course 6, module C, cycle II of the master curriculum of the Third Faculty of Medicine, Charles University
J. Horák, J. Fanta
Abbreviations:
DD ??..differential diagnosis
Def???definition
Dg?????.diagnosis
Et?????..etiology
Ci?????..contraindications
Lab????. laboratory findings
Th?????.. therapy 1. INTRODUCTION - problem delineation, definition, clinical importance
The gastrointestinal tract and other organs of the abdominal cavity may become a source of numerous subjective and objective problems of the patient. The causes of these problems may be functional, i.e. without a definable morphological or biochemical cause, or organic, where a cause can be defined. Diseases of the gastrointestinal tract and other organs of the abdominal cavity have a bearing on many clinical specialties (gastroenterology and hepatology, nephrology, urology, gynecology and obstetrics, oncology, infectious diseases, angiology, rheumatology, hematology, endocrinology etc.). Their clinical importance covers the whole spectrum of problems from subjective complaints that impair the quality of life of the affected patients but do not have any apparent consequences nor do they threaten the life of the patients (e.g., irritable colon) up to dramatic situations conveying high mortality (e.g, diffuse peritonitis, acute hepatic or renal failure). The appropriate medical approach must establish the correct diagnosis as fast as possible, introduce an effective treatment, remove all risk and complicating factors, initiate preventive measures and establish prognosis. At the same time, the physician must gain confidence and collaboration of the patient, which is necessary especially in chronic disease and last but not least he must take into account also the economic aspects of his activities. It is sometimes very difficult to bring all these requirements into harmony, yet to do it is an imperative that we must under all circumstances meet to the highest degrese possible. 2. MAIN GASTROINTESTINAL AND ABDOMINAL PROBLEMS 2.1. Dysphagia and the heartburn 2.1.1. Definition and clinical presentation
Dysphagia means difficult swallowing of the meals, odynophagia painful swallowing. 2.1.2. Etiology and pathophysiology
- anatomy of the esophagus - see textbooks of anatomy
- physiology of swallowing
Swallowing (deglutition) begins with the voluntary (oral) phase, during which the bolus is advanced into the pharynx by the tongue. There the bolus activates involuntary contraction of the pharyngeal muscles, i.e. the swallowing reflex. This is designed to ensure the passage of bolus through the esophagus at the same time inhibiting the bolus entry into the airways.
Dysphagia caused by a large bolus or by a narrowing of the esophagus lumen is called mechanical dysphagia whereas difficult swallowing due to impaired muscle coordination or weak peristalsis is called motoric dysphagia. The upper part of esophagus contains striated muscle innervated by n. vagus. The motoric neurons are cholinergic and excitatory. Motoric dysphagia of the pharynx may be the result of neuromuscular disorders causing muscle paralysis, non-peristaltic contractions or of the loss of the opening function of the upper esophageal sphincter. Clinical manifestation of the pharyngeal dysphagia usually overshadows impaired function of the cervical esophagus.
The musculature of the thoracic esophagus and of the lower esophageal sphincter (LES) is smooth and is innervated by preganglionic vagal fibers and postganglionic neurons from plexus myentericus. Meissner?s submucous plexus is of a limited importace in the esophagus. Vagal fibers are here both excitatory (mediator acetylcholine) and inhibitory (mediator nitric oxide). Dysphagia results if the peristalsis is weak or ineffective (e.g. in scleroderma) or when the LES fails to open as in achalasia.
Oropharyngeal dysphagia (oropharyngeal paralysis)
- etiology: myasthenia gravis, polymyositis, cerebral ischemia
- symptoms and signs: dysphagia, nasal outpouring of meal, aspiration
- auxilliary examination: X-ray - barium meal - disorder of the oral phase of swallowing, aspiration
Esophageal dysphagia:
- primary motility disorders: achalasia, esophageal spasm
Achalasia:
Def: motoric disorder of the esophageal smooth muscle, LES does not relax during swallowing
Pathogenesis: loss of intramural neurons of the myenteric plexus in the distal part of the esophagus
- primary - etiology unknown
- secondary - infiltrating carcinoma, lymphoma etc.
Sy: dysphagia, regurgitation, chest pain
Complication: aspiration
Dg: plain chest X-ray - gastric bubble is missing, occassionally dilated esophagus with the hydroaeric phenomenon can be seen
Barium meal swallowing: the patient is swallowing an X-ray contrast meal, during which he is examined both in the vertical and horizontal position. Side projection is a necessity. X-ray is indispensible for swallowing examination. It clearly shows esophageal stenoses, diverticula and hiatal hernia. In achalasia, esophageal dilatation, loss of peristalsis of the distal esophagus and its narrowing are present.
Th: - semiliquid diet
- pharmacotherapy: nitrates improve the esophageal passage (sublingual nitroglycerin up to 0.5 mg or isosorbid dinitrate 10 - 20 mg per os before meals). Anticholinergic agents are usually ineffective
- mechanic dilatation
- endoscopic treatment
- surgery (myotomy)
Esophageal spasm
Def: motoric disorder of esophageal smooth muscle, leading to numerous incoordinated contractions
- cause is unclear, histologically focal degeneration of neural fibers is found
Sy: retrosternal pain lasting seconds to minutes that may immitate pain of angina pectoris or reflux esophagitis, dysphagia
Dg: X-ray of the esophagus - uncoordinated simultaneous esophageal contractions, sometimes the so-called cork-screw esophagus, LES opens normally
Th: sublingual nitroglycerin, isosorbid dinitrate p.o., niphedipin before meals
- secondary motility disorders: benign stenoses, tumors, esophageal rings, compression from outside
Dg: X-ray, endoscopy
Th: according to etiology
- scleroderma: weakness of the lower two thirds of the esophagus, incompetence of LES
Sy: dysphagia following solid meals, on lying even after liquids, sometimes heartburn
X-ray: dilatation and loss of peristalsis of the distal esophagus
Th: ineffective, only the reflux esophagitis is amenable to treatment
- globus hystericus (pharyngeus)
Sy: lasting feeling of a lump in the throat, swallowing is not hampered
X-ray is normal
Th: psychotherapy 2.1.3. Diagnosis and differential diagnosis
- history: correctly taken history allows to presume dysphagia in more than 80% of cases. If problems are caused by solid meals only, mechanic dysphagia with moderate nerrowing of the lumen is present. If also liquids cause dysphagia, the stenosis is advanced. On the other hand, in motor dysphagia in achalasia and diffuse esophageal spasms the patient from the beginning has the same problems on swallowing solid meals and liquids. Patients with scleroderma suffer from dysphagia that follows solid meals independently on body position, dysphagia following liquids is present on lying but not on standing.
Imaging and other diagnostic methods:
X-ray: vide supra
Esophagoscopy: it allows direct visualization and biopsy of the esophageal mucosa. It enables to diagnose Barrett?s esophagus, esophageal varices, stenosis, esophagitis, diverticula, hiatal hernia, and esophageal ulcer.
Manometry: contemporary pressure registration in several parts of esophagus by means of pressure sensors.
Upper esophagus manometry enables differentiation among dysphagia resulting from CNS lesions, primary esophageal muscle lesions and cricopharyngeal dystonia.
Lower esophagus manometry is helpful in diagnosing achalasia, esophageal spasms etc.
Esophageal pH-metry and perfusion (Bernstein) test with 0.1N HCl: they are helpful in diagnosing gastroesophageal reflux disease
DD: stenocardia, pleuritis, pericarditis, vertebrogenic pain 2.1.4. Treatment
- treatment of underlying disease
- nutrition by means of a tube or gastrostomy (complication: aspiration)
- pharmacotherapy - vide supra
- dilatation
- endoscopic treatment
A new treatment option in esophageal achalasia is local injection of botulotoxin A. Botulotoxins selectively inhibit acetylcholine liberation from cholinergic nerve endings on muscle plates. Irreversible chemical denervation of muscle fibers follows. Due to regeneration processes the muscle function starts to appear again approximately after three months and its restituion is complete in another three month time. However, in clinical setting the therapeutic effect lasts considerably longer. The use of botulotoxin is limited by its high cost.
- surgical procedures 2.1.5. Preventive, prognostic and opinion aspects 2.1.6. Gastroesophageal reflex disease (GERD)
- reflux of the gastric contents into the esophagus damages esophageal mucosa (reflux esophagitis)
- pathogenesis: weakening of LES
- anatomy and physiology of LES
Et: - increased volume of gastric contents (after the meals, pylorostenosis, gastric hypersecretion)
- influence of body position (lying, recumbent)
- hiatal hernia
- increase of gastric pressure (obesity, ascites, gravidity)
- reflux esophagitis:
- moderate (histologically infiltration with granulocytes or eosinophils)
- errosive - endoscopically apparent
- scarring and stenosis of the esophagus - caused by esophageal wall fibrosis in chronic esophagitis
- Barrett?s esophagus - intestinal metaplasia (replacement of normal squamous epithel by cylindrical epithel) - increased risk of esophageal adenocarcinoma
Sy: heartburn, chest pain (occassionally simulating pain of angina pectoris), dysphagia in stenosis
- risk of aspiration
Dg: - history
- endoscopy + biopsy
- scintigraphy of the esophagus
- p
Annotation
Course 6 of the Module IIC (Gastrointestinal and abdominal complaints) delineates typical presentations of common gastrointestinal diseases and explains the basis of common symptoms and signs in hepatogastroenterology. Student will learn to use auxiliary laboratory tests and imaging procedures used in GIT diseases and to interpret their results.
Throughout the course, stress is laid on pathological and pathophysiologcal basis of GIT diseases. Fundamental therapeutic measures are mentioned.
Differential diagnosis of the main GIT syndromes and symptoms is discussed together with their probable prognosis.