Interventional Endoscopy (IE) involves the use of endoscopic equipment with other contemporary imaging modalities, such as fluoroscopy and/or ultrasound, to perform diagnostic and therapeutic procedures in virtually any part of the body accessed endoscopically (gastrointestinal, biliary, respiratory, urinary tract, etc).
Currently, an expanding investigation of the use of some novel techniques in veterinary medicine has been undertaken. The combination of endosocpy and fluoroscopy allows for one to visualize and gain access into small orifices that would otherwise require more invasive surgical technique. A good example of this is the placement of a biliary stent into the common bile duct via the major duodenal papilla with endoscopic and fluoroscopic guidance. Many of these interventional procedures are considered the standard-of-care in human medicine, and are currently being investigated in veterinary medicine. The use of these techniques are expanding as these modalities are becoming more widely available.
The invasiveness and morbidity associated with some traditional surgical techniques (i.e. biliary re-routing surgery, ureterotomy for ureteral obstructions, or nasopharyngeal surgery for nasopharyngeal stenosis) makes the use of minimally invasive alternatives using IE appealing. The advantages of such procedures are the minimally invasive nature, the lower morbidity, shorter hospital stays, and sometimes even the lack of alternative options. The disadvantages are that these procedures are technically challenges, require specialized equipment, and require specialized training.
This talk is a brief overview of some of the minimally invasive interventional endoscopic procedures actively being performed in veterinary medicine as well as some promising future applications currently under investigation. A large number of the procedures we are currently performing are in the urinary tract (ureteral stenting, laser lithotripsy, urethral stenting, urethral bulking agent injections for incontinence, etc), and this will not be the focus of this discussion, as another session will focus on endourology.
A C-arm fluoroscopy unit is ideal for most of the IE procedures we are currently performing. This unit has the advantage of mobility of the image intensifier, permitting various tangential views without moving the patient and positioning of the patient where endoscopy is easiest (i.e. at the end of the table for rigid cystoscopy). Ultrasonography is useful for percutaneous needle access into structures (gall bladder, renal pelvis, etc) making portable ultrasound very valuable. Guidewires of various size, shape, length, and stiffness, as well as catheters and stents of various materials, shapes, and sizes are needed for each procedure.
Endoscopes are used to guide the operator toward the orifice where visualization and access is needed (i.e. common bile duct, ureteral orifice, nasopharyngeal stenosis). Various flexible and rigid endoscopes are used for interventional endosurgical techniques. Flexible gastroduodenoscopes (6 mm and 8 mm), bronchoscopes, and ureteroscopes (7.5-8.2 french) are classically used for various body system interventions. Rigid endoscopes (1.9-7.5 mm) are also useful for cystoscopy and rhinoscopy. An adult (11 mm) or pediatric (9mm) side-view duodensocope is necessary for endoscopic retrograde cholangiopancreatography (ERCP) and biliary stenting. Other specialized catheters and guidewires are needed for the particular procedure (see presentation).