By Dr. Vikas Singla, Director & Head, Gastroenterology Max Super Speciality Hospital, Saket, New Delhi
Endoscopic procedures have undergone tremendous advances in recent years paving way for an advanced and minimally invasive approach towards the treatment of a multitude of disorders pertaining to the Gastro-intestinal Tract (GI Tract). Being such a remarkable tool, Endoscopic Ultrasound (EUS) has made a paradigm shift in the management of patients suffering from various GI tract disorders.
As the purpose of innovation is to change the treatment of various diseases towards a better and lesser invasive direction with a lesser criterion, various diagnostic and therapeutic procedures can be performed without a scar on the skin using EUS. Performing the ultrasound from within the GI Tract, EUS makes use of a miniature ultrasound probe attached to the tip of the endoscope that helps in obtaining high-quality and informative pictures.
After the fasting of at least 8 hours, Endoscopic ultrasonography is performed under sedation, making it a painless procedure. During EUS, structuring surrounding the esophagus, stomach, upper intestine, and lower part of the large intestine are studied. Patients suffering from disorders of the gall bladder, bile duct, pancreas, and lymph node enlargement may benefit from the procedure. If tissue sampling is planned, blood thinners medications need to be stopped after discussion with the doctor. Tissue samples are also obtained if required, and now with the newer needles, even the biopsies can be done during the procedure.
EUS – Treating a multitude of disorders
1. Evaluation of the cause of Jaundice – While normal ultrasound may show the presence of obstructed ducts but often fails to detect the cause. Endoscopic ultrasonography is extremely useful to test to detect the cause of jaundice especially if the stones are the cause of obstruction of the bile duct, many such stones migrating from the gall bladder. Once the stones are detected, removal can be done in the same setting, by another endoscopic procedure known as Endoscopic retrograde cholangiopancreatography or ERCP. Cancer of the bile duct, gall bladder, and pancreas are the other common cause of bile duct obstruction leading to jaundice and is more common in the elderly. EUS can easily detect these tumors, and sampling can be done in the same setting without any risk of the spread of the tumor.
2. Evaluation of pancreatic pathologies – Alcohol, smoking, and gall bladder stones are the common risk factors for pancreatic pathologies such as acute pancreatitis, chronic pancreatitis, and pancreatic cancer.
a) Acute Pancreatitis – Patients with acute pancreatitis can have severe pain in the upper abdomen and vomiting. After treatment of acute pancreatitis, further episodes should be prevented by treating the underlying cause. One of the common causes of acute pancreatitis is gall bladder stone, which may migrate in the bile duct and transiently block the pancreatic duct at the ampulla, leading to acute pancreatitis. Stones causing acute pancreatitis may be very small and maybe missed by ultrasonography. EUS can essentially detect very small stones in the gall bladder, treating which will prevent further episodes of acute pancreatitis.
b) Chronic pancreatitis – Individuals consuming alcohol or having predisposing genetic factors, can suffer from persistent pain in the upper abdomen, which can be due to chronic pancreatitis, a condition that can lead to stone formation and dilatation of the duct pancreas. In the early stage, conditions may be missed by the conventional techniques. EUS provides the highest level of information in this stage and can change the management of the disease altogether.
In patients with both acute and chronic pancreatitis, fluid may accumulate around the pancreas, forming a cyst known as a pseudocyst. The best treatment of pseudocyst nowadays, is drainage in the stomach and upper part of small intestine, under the EUS guidance. EUS guided drainage avoids the need for surgery and placement of external tubes.
c) Pancreatic Cancer – Patients with diabetes and a history of smoking are at increased risk of cancer, the common symptoms are pain upper abdomen and jaundice. EUS can detect the smallest cancer in the pancreas, define the extent, and enable tissue sampling without compromising resectability. The cystic lesion in the pancreas are common and can be due to pancreatitis or may be due to tumor formation. EUS is the best tool to define the nature of the lesion and is a useful guide for further treatment.
3. Cancer Pain Management – Many patients with cancer of the upper digestive tract can have severe pain abdomen, which is not controllable by oral medications. EUS guided injection around the nerve fibers carrying the pain sensation is a useful modality for pain relief. Small stones in the gall bladder known as microliths and early chronic pancreatitis are common causes of upper abdomen pain, which are often missed by conventional techniques. EUS is the best performing test in such conditions enabling early diagnosis and treatment.
4. Treatment of jaundice and vomiting in patients with pancreatic cancer – Patients with pancreatic lesions may suffer from vomiting and jaundice due to obstruction of the stomach and bile duct respectively. In both conditions, stent placement may be necessary depending upon the circumstances and tumor spread. EUS guided stenting is emerging as a new technique for the treatment of jaundice and vomiting. Moreover, once the conventional techniques fail, EUS is a useful rescue technique.
5. Control of bleed in patients with liver cirrhosis – In patients with cirrhosis of the liver, veins of the esophagus and stomach may dilate and are known as varices. Varices in the stomach require an injection of a special fluid known as glue. Placement of coils in varix under the EUS guidance prior to glue injection makes the procedure very safe.
6. Evaluation of fever – Prolonged fever may be due to enlargement of the lymph nodes, which can be due to various diseases such as tuberculosis, sarcoidosis, and tumor of lymph nodes such as lymphoma. A sampling of the nodes is necessary to define the cause and for further treatment. EUS is very safe in such conditions and enables the direct visualization and sampling of the lymph nodes.
