Tuesday, August 24, 2010

Esophageal Diagnostic Procedures

Esophageal Diagnostic Procedures

1. Definition
A. There are several procedures utlitized for the diagnosis of esophageal disease, and the approach must be tailored to the specific disease entity. Contrast swallow and esophagoscopy are commonly used for most patients with esophageal disorders, with CT scanning, endoscopic ultrasound, and reflux testing reserved for more specific indications. MRI and nuclear medicine scans may have additional limited roles.

2. Esophagoscopy
A. Indications
1) Dysphagia, odynophagia, regurgitation, hematemesis, chest pain, foreign body ingestion, or history of traumatic esophageal tear
2) Should usually be preceded by contrast swallow/cineesophagogram to help localize the site of disease
3) Contraindications include aortic aneurysm (can rupture), recurrent nerve paralysis, esophageal diverticulum (can perforate blindly), corrosive strictures (can perforate - stop when you see the stricture), and kyphoscoliosis (may be impossible)
4) Use rigid technique when Zenker's diverticulum or disease of the upper third is suspected, as flexible esophagoscopy is done blindly and can perforate in these areas
B. Technique - Rigid Esophagoscopy
1) Topical or general anesthesia may be used; general anesthesia generally provides better relaxation, lowering the risk of perforation
2) The 9mm scope is adequate for most adult patients
3) The patient is positioned supine with head and shoulders over the end of the table
4) Introduce the esophagoscope into the right side of the mouth and rest the shaft on your left thumb
5) The scope is advanced behind the right arytenoid cartilage into the right pyriform fossa
6) Lower the patient's head as the scope is advanced past the cricopharyngeus
7) Lower the head further and move to the right to pass through the gastroesophageal junction
8) Full examination is done on withdrawal, as folds of mucosa may hide pathology during advancement of the scope
C. Technique - Flexible Esophagoscopy
1) Topical anesthesia with sediation is usually adequate
2) The patient is placed in the left lateral position
3) The esophagoscope is introduced blindly with gentle pressure as the patient swallows
4) Insufflation of air distends the esophagus for complete visualization
5) Advance scope into upper stomach and perform thorough examination upon withdrawal
D. Complications
1) Perforation occurs in 0.1-0.25% of patients
2) Most commonly occurs posteriorly at the upper opening of the esophagus when forceful pressure is applied against the cricopharyngeus
3) Other sites include the diaphragmatic hiatus and diverticuli
4) Perforation can also occur after deep biopsy, forceful dilation of strictures, or during removal of foreign bodies
5) Chest pain after esophagoscopy is an indication of perforation and should be promptly evaluated
E. Findings in Disease
Reflux Esophagitis
Stage I localized spots of erythema, some with exudate
Stage II confluent areas of erythema
Stage III circumferential areas of erythema, friable, bleeds readily when touched
Stage IV deep ulcers, stenoses and columnar metaplasia

1) Barrett's esophagus: stratified squamous epithelium replaced by columnar epithelium and may become discrete ulcer; biopsy should be performed to look for malignancy
2) Stenosis: congenital stenoses usually have normal mucosa; acquired stenoses are usually associated with esophagitis or ulcers
3) Corrosive esophagitis: acute inspection shows edematous, friable walls which are easily perforated; stop at first area of injury
4) Diverticulum: exclude ulcers and neoplasms at the site of the diverticulum
5) Varices: range from small bluish elevations to large dilated veins at the lower end of the esophagus--commonly found in cirrhotics
6) Hiatal hernia: redundant folds in the lower esophagus and lack of diaphragmatic support are characteristic only in true hiatal hernia
7) Achalasia: markedly dilated, inflamed esophagus with thickened walls; GE junction has normal tone but may be hard to negotiate
8) Carcinoma: typically large fungating mass that bleeds easily, less commonly a smooth stenosis with edematous mucosa. Microinvasive carcinoma presents as slight discolorations of the mucosa, known as leukoplakia or erythroplakia.
9) Benign neoplasms: leiomyomas, fibromas, and lipomas are all covered with normal mucosa

3. Endoscopic Ultrasound
A. Particularly applicable in defining tumors and varices
B. May become useful in staging of esophageal cancer
C. 5 layers are identified: mucosa, deep mucosa, submucosa, muscularis, and adventitia
D. Extension of tumors into periesophageal structures and lymph nodes can be evaluated
E. Carcinomas appear as indistinct, echo-poor lesions; varices appear as round, echo-poor lesions

4. Gastroesophageal Reflux Evaluation
Note: Radiographic tests for GE reflux are not highly reliable for pathologic reflux, as up to 25% of patients will have reflux without associated pathology. Such tests can rule out patients with no reflux, however.
A. Manometry
1) Intraluminal pressures are measured using a continuous infusion catheter system while the patient is lying supine
2) This catheter is withdrawn at 1-cm intervals to obtain resting pressures
3) The catheter is reinserted, and pressures measured after swallowing at 1-cm intervals
4) This test is essential in delineating the various esophageal motility disorders
B. pH Reflux Test
1) A pH probe is placed 5 cm above the GE junction
2) 200 to 300 ml of 0.1N HCl is instilled in the stomach
3) A fall in pH below 4.0 during various maneuvers indicates GE reflux
C. Acid Perfusion Test
1) The distal esophagus is perfused in an alternating fashion with 0.1N HCl and saline
2) The test is positive if atypical chest pain occurs during acid perfusion and resolves during saline perfusion
3) High rates of false positivity and false negativity make the test somewhat unreliable
D. 24-hour pH Monitoring
1) a pH probe is placed 5cm above the GE junction
2) The patient records any symptoms and pH changes are monitored constantly over 24 hours
3) Analysis includes percentage of time pH was less than 4.0, and percentage of time patient was upright and supine
4) The number of reflux episodes, the duration of the episodes, and the longest episode of reflux are also evaluated
5) This test gives the most objective evidence of reflux

5. Therapeutic Esophagoscopy
A. Removal of Foreign Bodies
1) Rigid esophagoscope is best
2) Most common sites are just below the cricopharyngeus and at the diaphragm
3) Sharp objects carry the highest risk of perforation
B. Dilation of Strictures
1) Savary-Gilliard dilators are the safest
2) A metal guidewire is passed through the stricture using the esophagoscope
3) The stricture is then dilated using progressively larger dilators passed over the guidewire
4) Retrograde dilation may also be done using Tucker dilators over a string passed through a gastrostomy and out the mouth
C. Corrosive Esophagitis
1) Esophagoscopy should be performed to confirm the burn, but do not pass the injured area
2) Dilation can be performed after burn have healed (usually 3-4 weeks) if strictures have formed
D. Carcinoma
1) Palliative dilation usually is only temporary, and should be followed with either laser resection or stenting
2) The Nd:YAG laser can be used from above or below to core a passage through tumor and permit swallowing
3) Brachytherapy can be applied after endoscopic dilation for inoperable carcinoma
E. Achalasia
1) Dilation can be performed of the GE junction if surgical myotomy is contraindicated
2) Perforation, however, is a definite risk and can present as either chest or abdominal pain
F. Variceal bleeding
1) Electrocautery and laser therapy of bleeding varices do not prevent rebleeding
2) Sclerotherapy is probably best and obliterates current varices; however, rebleeding occurs in 40% of patients

6. Radiographic Examples
A. Schatzki's ring
B. Achalasia
C. Diffuse Esophageal Spasm
D. Leiomyoma
E. Carcinoma

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