Endoscopic Treatment of Precancerous Lesions and Early Carcinoma

Both open resection and endoscopic techniques are available for the treatment of precancerous lesions and early carcinomas of the esophagus and stomach.

■ Open Resection

The advantages of open resection are that it permits a more radical tumor removal and allows for extensive histological processing and evaluation of the excised tissue.

Disadvantages include problems associated with the postoperative defect, the operative mortality and morbidity, and the limitations that are frequently imposed by coexisting illnesses.

■ Endoscopic Treatments

Endoscopic treatment options include polypectomy, endoscopic mucosectomy, and photodynamic therapy. Endoscopic polypectomy is a long-established procedure, while mucosectomy and photodynamic therapy have been increasingly performed in recent years.

■ Polypectomy

Key Characteristics

► The polyp is snared with a wire loop and transected at the base with high-frequency diathermy.

Indication

► Gastric and duodenal polyps that are 10 mm or larger in diameter

Contraindications

► Coagulation defect (Quick prothrombin time [PT]: < 50%, platelets: < 50 000/jiL)

► Intramural tumors

Technique

► Preprocedure checklist

- Informed consent?

- Coagulation studies?

- Aspirin discontinued five days before procedure?

- Emergency instruments and equipment available?

► Preparations

- Place the neutral electrode on the patient's thigh.

- Set up the high-frequency diathermy unit.

- Check the function of the polypectomy snare.

► Polyp removal

- Visualize the polyp.

- For a larger polyp, infiltrate the base with epine-phrine or secure it with a clip.

- Place the open snare over the polyp, and tighten the snare under vision.

- Gently lift the snared polyp.

- Switch on the cutting and coagulation current.

- Retrieve the severed polyp. ► Inspect the resection site.

Complications

► Perforation

■ Endoscopic Mucosectomy

Key Characteristics

► Endoscopic mucosectomy is an increasingly common procedure used for the treatment of early carcinomas in the esophagus and stomach.

Indications

Early esophageal carcinomas confined to the mucosa Small early carcinomas in the stomach Large adenomas in the stomach

Technique

Pick up the suspicious mucosa with the biopsy forceps or suck the mucosa into a suction cap.

Place a snare over the raised mucosa and resect the tissue.

Technical details of the procedure are operator-dependent.

■ Photodynamic Therapy

Key Characteristics

► A photosensitizing agent is administered that becomes concentrated in the malignant or premalignant lesion.

► Several agents are available: dihematoporphyrin ether, 5-aminolevulinic acid (5-ALA), and meta-tetra(hydroxy-phenyl)chlorin.

► Several hours after the agent is administered, light is applied locally to induce a photochemical reaction leading to tissue necrosis.

Indications

► Dysplasia and early carcinoma in the setting of Barrett esophagus

► Early esophageal carcinoma

Evaluation

- Suitable for inoperable patients

► Disadvantages

- The lesion is destroyed and therefore unavailable for his-tological processing and definitive staging.

- High costs and problems with dose adjustment

■ Incidence and Location

It is common for foreign bodies to be swallowed, and 70% of the patients are children. Approximately 80-90 % of swallowed objects will pass spontaneously through the gastrointestinal tract, while 10-20 % will need to be removed endoscopically. One percent will require surgical removal. Swallowed objects most frequently become lodged at the physiological constrictions of the esophagus and at sites of abnormal narrowing (strictures, rings, or malignant tumors).

The complaints are highly variable and can range from essentially no complaints, a globus sensation, or retrosternal pain to signs of complete esophageal obstruction or perforation. Objects that pass through the lower esophageal sphincter will usually be eliminated by the natural route.

Injuries from swallowed objects may be caused by pressure necrosis (coins, etc.), pricks and lacerations (needles, razor blades), or toxins (batteries, drug-packed condoms).

■ Rules for Management

Indications

Endoscopic foreign body removal is recommended for:

► Objects that are sharp or pointed, larger than 2 cm or longer than 5 cm, and for toxic objects

► All foreign bodies that are stuck in the esophagus

► Patients who have had gastrointestinal surgery

► Patients with prior diseases of the gastrointestinal tract

Prior to Endoscopy

► Plain chest radiograph (no contrast medium due to risk of aspiration)

► Plain abdominal radiograph

► Assess the need for intubation (especially with foreign bodies that are difficult to grasp).

► If possible, perform a trial run using a duplicate object.

► Check the indication for surgical removal.

Materials

A range of different instruments are available for foreign body retrieval (Fig. 4.30):

► Foreign-body grasping forceps

► Polyp forceps

► Stone-retrieval baskets

► Esophageal dilating balloons

Follow-Up

► Clinical follow-up visits

► Radiographic follow-ups (perforation?)

A wait-and-see approach is recommended for objects that are round or blunt, smaller than 2 cm or shorter than 5 cm, and nontoxic. The patient should be observed for 10 days. If the foreign body is still detectable within the stomach at that time, it should be retrieved endoscopically.

Fig. 4.30 Instruments and methods for endoscopic foreign-body removal a Stone-retrieval basket for extracting foreign bodies a Stone-retrieval basket for extracting foreign bodies

Fig. 4.30 Instruments and methods for endoscopic foreign-body removal

b Triprong grasper for extracting round foreign bodies

c Toothed forceps for removing small irregular objects b Triprong grasper for extracting round foreign bodies c Toothed forceps for removing small irregular objects d Method for retrieving the bumper from a cut PEG tube e An overtube is used when removing sharp or jagged objects f Method for removing an object with a hole in it

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