Definition & Overview
Transendoscopic ultrasound-guided intramural or transmural fine needle biopsy is a procedure where a thin, hollow needle is inserted into a specific part of the body to collect tissue and cell samples. It can be performed for diagnostic purposes, to determine the best possible treatment for patients, and to assess the effectiveness of such treatment.
The needle is typically inserted into an abnormal growth or tissue or cells that have undergone significant physiologic changes. This procedure is commonly done in the gastrointestinal tract, and when examining the current state of the liver, gallbladder, and other adjacent organs.
In the past, when an abnormal growth is detected inside the body, there was no way to make an absolute diagnosis except to collect a biological sample. Before the advent and wide acceptance of fine-needle biopsy, physicians perform an open surgical biopsy, in which the patient in placed under undue stress and trauma when a part of their body is opened or excised. Such procedures are associated with various complications including bleeding and infection. The use of fine needles with hollow centres has transformed this previously complicated procedure into a relatively simple and safe one.
With the introduction of endoscopy, accessing the internal body parts and collecting its images have become quite easy. An endoscope is a thin, hollowed tube composed of an insertion tube and bendable tip where an ultrasound device is connected. This device transmits and receives ultrasonography waves for imaging. The hollowed centre, termed the working channel, is where surgical instruments are inserted. Coupled with ultrasound imaging, this procedure has become the preferred method for performing transendoscopic ultrasound-guided intramural or transmural fine needle biopsy.
Who Should Undergo and Expected Results
Patients suffering from the following diseases qualify for this procedure:
Barrett’s oesophagus – A condition where cells that line the oesophagus transform into metaplastic columnar cells. These cells need to be evaluated, as they can potentially lead to the development of adenocarcinoma of the oesophagus.
Oesophageal cancer – For this condition, the procedure is performed to determine the stage of cancer and its extent. In some cases, the appropriate treatment is recommended following the evaluation of the collected biopsy samples.
Polyps in the intestine - The growth of these polyps is associated with a genetic mutation and can occur anywhere in the intestinal tract. If left untreated, these polyps could lead to severe complications like bleeding and cause cancer.
Malabsorption syndromes or any infection of the gastrointestinal tract - In such cases, this procedure is used to collect biopsy samples to determine the cause and suitable treatment.
Colon cancer - Those who have abnormal growths in the colon or are suspected of having colon cancer can also undergo this procedure for a definitive diagnosis and treatment selection. In some cases, a fine needle biopsy is also indicated to monitor the effectiveness of treatment.
An advanced stage or persistent haemorrhoids
Rectal bleeding, pain in the abdomen, and significant changes in bowel habits – Patients who suffer from these symptoms often undergo sigmoidoscopy, which is the examination of the lower parts of the colon and part of the rectum. Included in this procedure is the collection of biopsy samples using endoscopy.
Abnormal masses or growths in the liver and gallbladder – For these conditions, the procedure is performed to determine malignancies. An examination of the nearby pancreas might also be warranted if the condition has spread.
This procedure can also be recommended for those who underwent surgery of the jejunum to evaluate the results. A fine needle biopsy through endoscopy can confirm if the gastrointestinal tract has achieved anastomosis, in which two formerly distant parts of the intestine were surgically joined. This is one of the expected results after bariatric or weight loss surgery.
The results of transendoscopic ultrasound-guided intramural or transmural fine needle biopsy are referred to a pathologist for evaluation. The procedure itself is considered simple and relatively safe. It is typically done in an outpatient setting and the patient is allowed to go home afterwards.
How is the Procedure Performed?
The patient is asked to lie on their sides in preparation for this procedure. A topical anaesthesia is then applied, though some cases would warrant intravenous administration of sedative agents. To help relax the whole gastrointestinal tract and prevent peristalsis, an antispasmodic agent is also given. A bite block is also placed in the mouth to prevent the patient from reflexively closing the oral cavity and biting down on the endoscope.
The endoscope is then introduced and made to pass through the pharynx, oesophagus, and the rest of the gastrointestinal tract. Air is introduced to distend and inflate the lumen. This is done to provide better imaging results. The images generated from the ultrasound device is transmitted and viewed on a specialised screen. The needle is then advanced and inserted into the targeted lesion or growth. A negative suction pressure is then applied to aspirate cell samples. In some cases, the physician might decide not to apply negative suction pressure to aspirate and collect biopsy samples. This technique, however, requires two or more passes to get an adequate amount of tissue sample. Once done, the suction is turned off, and the needle is withdrawn from the endoscope. Tissue samples are then placed in formalin and smeared in glass slides in preparation for pathological evaluation.
Possible Risks and Complications
- Soreness and pain when swallowing during the first few hours after the procedure
- Risk of bleeding if the gastrointestinal tract lining has been injured
- Bacterial infection
Adverse reaction to anaesthesia that could lead to difficulty in breathing and accelerated heartbeats
Han, X.-M.; Yang, J.-M.; Xu, L.-H.; Nie, L.-M.; Zhao, Z.-S. (2008-08-01). "Endoscopic ultrasonography in esophageal tuberculosis". Endoscopy. 40 (8): 701–702. doi:10.1055/s-2008-1077479. ISSN 1438-8812. PMID 18680081.
Yusuf TE, Harewood GC, Clain JE, Levy MJ (January 2006). "International survey of knowledge of indications for EUS". Gastrointest. Endosc. 63 (1): 107–11. doi:10.1016/j.gie.2005.09.032. PMID 16377326.