Endoscopic Ultrasonography Examination

1. Introduction

   Endoscopic ultrasonography is a technique and endoscopic examination which encompasses both functions of endoscopy and ultrasound. Apart from direct inspection of mucosal surface of the gastrointestinal tract by using the endoscopic function, the ultrasound probe at the tip of endoscope also allows doctors to study internal organs by close proximity. Furthermore, doctors can get tissues or cytopathological diagnoses by means of fine-needle aspiration or even tru-cut biopsy under the guidance of endoscopic ultrasound. Hence, it is now widely used in diagnosis of various diseases of the esophagus, stomach, pancreas, gallbladder, liver, colon and lung. More importantly, it is used for staging of cancer of various organs mentioned above. Apart from diagnostic purpose, therapeutic use is possible such as celiac plexus neurolysis and drainage of pancreatic pseudocysts.

2. Preparation

   • Patients are required to be fasted for at least 6 hours before the procedure.
   • Inform the medical staff of any major medical problems like diabetes mellitus, hypertension, valvular heart disease and pregnancy, and continue medications as instructed.
   • Provide information concerning current medications especially anti-platelet and anti-coagulation drugs and any allergic history.
   • Avoid driving to attend the out-patient procedure and also avoid smoking, alcohol drinking and taking sedatives before the procedure.
   • Elderly patients and those with difficulty in walking may be admitted to the hospital for the procedure.

3. Procedure

   • Patients will receive intravenous sedation prior to the examination to reduce any anxiety or discomfort that may arise from the procedure.
   • Local anaesthetic will also be applied to the throat of patients. Then, a flexible endoscope with an ultrasound probe over its tip with a diameter of about 1-1.4cm will be inserted by the endoscopist through the mouth into the gastrointestinal tract.
   • Minor discomfort including nausea and abdominal distension is common and will resolve with time.
   • Patients will remain conscious during the procedure.
   • Generally speaking, a diagnostic procedure will last for 15-30 minutes. In complicated cases that require additional therapies or fine needle aspiration, the procedure time will be prolonged.
   • Patients’ co-operation with medical staff will also help shorten the examination time.

4. After the examination

   • The effect of local anaesthesia will persist for around an hour. Patients should remain fasted until local anaesthesia has worn off. This will prevent choking during food or fluid intake.
   • If intravenous sedation is used, patients should avoid operating heavy machinery, signing legal document or driving for the rest of the day.
   • Patients should follow the instruction given by the medical staff in completing the drug treatment.

5. Complications

   • Local anaesthetic will cause numbness over throat for about an hour.
   • Complications specific to endoscopic ultrasound guided fine-needle aspiration or trucut biopsy will depend on the site of interest and these include mediastinitis, pancreatitis and infection.
   • Complications specific to celiac plexus neurolysis include transient diarrhea, transient orthostasis, transient increase in abdominal pain and abscess formation.
   • Major complications including perforation, bleeding and cardiopulmonary events may occur but their risks are less than 1%.
   • Likelihood of the development of complications depends on individual circumstances and types of treatment.
   • In case major complications occur, emergency surgical intervention may be required. Death may also happen if serious complication occurs. Patients should consult the attending physicians for the detail of the endoscopic procedures.

6. Remarks

   Should you have any queries, please consult doctor-in-charge.