Statements & Guidelines
South African Gastroenterology Society (SAGES) position statement on the SpyGlass Direct Visualization System (Boston Scientific)
Choledocholithiasis is present in 7 - 12% of patients with cholelithiasis and is responsible for significant morbidity. Although stone clearance by means of an ERCP is achieved in 87 to 97% of patients, a significant minority requires more than one intervention. Increasing stone size and complexity often result in the need for several ERCPs and it is particularly in this subset of patients that alternative management options are required.
Biliary and pancreatic duct strictures often have major clinical implications and the distinction between benign and malignant strictures can be difficult. Conventional ERCP is often unhelpful in making this critical distinction and brush cytology has a low diagnostic yield.
Direct visualization of the biliary tree and main pancreatic duct remains the ne plus ultra in biliopancreatic endoscopy and enables the operator to apply optically guided therapy such as electrohydraulic lithotripsy to large stones, to visually evaluate strictures and to perform targeted biopsies of strictures.
Clinical situations in which cholangioscopy may potentially be useful include Diagnostic Indications
- Biopsy of indeterminate strictures in patients without primary sclerosing cholangitis
- Exclusion of malignancy in a stricture in primary sclerosing cholangitis
- Diagnosing cholangiocarcinoma
- Indeterminate filling defect in the bile duct on imaging or ERCP
- Precise pre-operative location of biliary and pancreatic intraductal tumors
- Visual evaluation and biopsy of post-transplantation biliary strictures and intraductal mucinous neoplasm
- Biliary stone extraction by means of electrohydraulic or laser lithotripsy
- Cystic duct stent placement
- Pancreatic duct stone extraction
In practice it is anticipated that cholangioscopy will be largely confined to the treatment of large/complicated stones and the assessment of biliary strictures for malignancy.
SpyGlass Direct Visualization System
The SpyGlass Direct Visualization System is a mother–daughter scope system designed to provide direct visualization of the biliary tree and pancreatic duct for diagnostic and therapeutic applications.
The SpyGlass Direct Visualization System is an integrated platform that consists of the following components
- SpyGlass Access and Delivery Catheter (disposable)
- Optical probe (reusable)
- Biopsy forceps (disposable)
The SpyScope Access and Delivery Catheter has 4 lumina (1 for the Spyglass Optical Probe, 1 for the SpyBite forceps or electrohydraulic lithotripsy probe or laser probe) and 2 irrigation channels. Its unique 4-way tip deflection enables better navigation and visualization of the biliary tree.
The SpyGlass Optical Probe is a multiple-use fibreoptic device that transmits a 6000-pixel image bundle. It has a 70° field of view but images are inferior to those captured by video cholangioscopes.
The SpyBite Forceps jaw has a central spike and a 1 mm outer diameter.
The SpyGlass Direct Visualization System has a number of advantages over other cholangioscopic techniques
- Single operator control of the duodenoscope and SpyScope (previous systems typically require 2 specialists)
- Four-way steering capability
- Two independent irrigation channels for flushing of debris
- Real-time direct visualization of the bile and pancreatic ducts
- Targeted biopsy capability
- High degree of complete clearance of large and complex stones
- Disposable and multi-use components
The SpyGlass Direct Visualization System does not replace ERCP for the vast majority of common bile duct stone extractions. It should however be available for patients who have undergone multiple ERCPs for large impacted stones or have biliary/pancreatic strictures that defy diagnosis.
Conventional ERCP remains the procedure of choice for the treatment of choledocholithiasis and the initial evaluation of suspected biliary strictures.
The SpyGlass Direct Visualization System enhances our ability to treat patients with complex biliopancreatic disease. In practice, its use will be largely confined to the treatment of large/complicated stones that cannot be removed by conventional means and the assessment of biliary strictures for malignancy.
A growing body of literature on per oral cholangioscopy attests to its efficacy and safety. The American Society for Gastrointestinal Endoscopy views cholangioscopy with intraductal
lithotripsy as an established modality for the treatment of difficult biliary stones. When used
for the evaluation of indeterminate biliary strictures, cholangioscopy increases the diagnostic yield of tissue sampling.
SAGES is aware that Boston Scientific has approached the funders for a health technology assessment. As the body representing gastroenterologists in South Africa, SAGES welcomes the introduction of this new technology into South Africa. It envisages that here, as elsewhere, cholangioscopy will be performed only by experienced endoscopists well versed in advanced endoscopic procedures, that specialized training of medical staff will be required and that utilization of the procedure will be confined to a limited number of referral centres. Whilst the submission by Boston Scientific provides all the pertinent information, SAGES invites the reviewers of this technology to discuss any outstanding issues with the SAGES Council Member responsible for guidelines.