echoendoscopes

Echoendoscopes are specialized endoscopes equipped with an ultrasound transducer at the tip, allowing endoscopic ultrasound (EUS) imaging from within the gastrointestinal tract. They enable high-resolution visualization of structures adjacent to the GI tract and provide a path for tissue sampling and various interventional procedures under real-time ultrasound guidance.

There are two main configurations. Radial echoendoscopes emit ultrasound in a 360-degree sector perpendicular to the scope axis, producing a circular image of surrounding tissues and organs. Linear echoendoscopes use a curved linear array to generate imaging in a single plane parallel to the scope and permit real-time guidance of needles or catheters for fine-needle aspiration or biopsy and other interventions.

Echoendoscopes are used for diagnostic and therapeutic purposes. They help evaluate pancreaticobiliary disease, submucosal lesions, mediastinal and abdominal lymph nodes, and other structures adjacent to the GI tract. They support EUS-guided fine-needle aspiration/biopsy, cyst drainage, biliary drainage, and various drainage or pain-relief procedures, often with Doppler imaging to assess vascular structures and blood flow. The choice between radial and linear scopes depends on whether purely diagnostic imaging or interventional capability is prioritized.

Procedures with echoendoscopes are typically performed under sedation or anesthesia. Practitioners consider patient factors, anticoagulation status, and potential risks such as infection, pancreatitis, bleeding, perforation, and adverse reactions to sedation. Training and experience influence diagnostic accuracy and safety, and successful use relies on specialized equipment, sterile technique, and coordinated imaging and handling during procedures.

Historically, EUS emerged in the late 20th century, with radial scopes introduced first and linear scopes enabling interventional EUS in the 1990s and beyond. Continuous advances have improved image resolution, needle types, and accessory devices used with echoendoscopes.