Endosonography (EUS) is a versatile diagnostic and therapeutic procedure with numerous applications, particularly in gastroenterology and oncology. Its primary uses include:
1. Oncological Staging and Diagnosis:
* Gastrointestinal Cancers: Diagnosis, staging, and biopsy of cancers affecting the esophagus, stomach, rectum, bile ducts, and pancreas. This includes early detection of malignancies.
* Local Staging: Detailed assessment of tumor invasion depth (T-staging: T1-T4) and involvement of adjacent structures (e.g., prostate, bladder, vagina) and regional lymph nodes/vessels, especially for rectal cancers.
* Recurrence Monitoring: Investigation of recurrent disease following surgical interventions.
* Biopsy: EUS-guided fine-needle aspiration (FNA) or biopsy of suspicious lesions in the liver, intra-abdominal lymph nodes, and pancreatic masses.
2. Evaluation of Submucosal Lesions:
* Identification and characterization of lesions originating from the wall of the gastrointestinal tract (esophagus, stomach, rectum), such as gastrointestinal stromal tumors (GIST) and leiomyomas.
3. Pancreatic Disorders:
* Acute Pancreatitis: Detection and drainage of peripancreatic fluid collections (pseudocysts) and necrotic tissue in cases of necrotizing pancreatitis.
* Chronic Pancreatitis: Comprehensive evaluation of the pancreatic parenchyma and ductal system.
* Pain Management: EUS-guided celiac plexus neurolysis for pain relief in pancreatic cancer.
4. Anorectal Conditions:
* Anal Fistula: Diagnosis, classification, and precise mapping of the fistula's relationship with the anal sphincters.
* Fecal and Gas Incontinence: Assessment of the thickness and integrity of the anal canal musculature.
5. Therapeutic Interventions:
* Biliary Drainage: EUS-guided drainage or stenting for malignant biliary obstruction into the stomach or small intestine.