Role of EUS in CBD stones A Aljebreen, MD, FRCPC Head of Gastroenterology Unit, King Khalid University Hospital, Riyadh, Saudi Arabia 8th International Workshop on Therapeutic Endoscopy Egypt, Dec 11, 2006

Overview Introduction Technique Performance of EUS in detection of CBD stones EUS vs ERCP EUS vs MRCP Conclusion

Introduction Common bile duct (CBD) stones occur in 10-15% of patients with symptomatic gallstones undergoing cholecystectomy. ERCP overall complication rates of 5-10% and mortality rates of 0.02% to 0.5%.

Introduction When the clinical features strongly suggest the presence of CBD stones (high risk), management is fairly straightforward. Unfortunately, the clinical picture is often equivocal (low to moderate risk). Thus, an accurate, noninvasive, reliable, and safe method would be highly advantageous. EUS is emerging as reliable substitutes for diagnostic ERC.

*Sugiyama. Gastrointest Endosc 1997; 45(2):143-146. Introduction EUS has a procedural risk identical to that of gastroscopy the rate of perforation is less than 1 in 2000. The extra hepatic ductal system can be visualized completely by EUS in 96% of patients*. *Sugiyama. Gastrointest Endosc 1997; 45(2):143-146.

EXAMINATION TECHNIQUE There are basically two positions. The first position is called the “apical” position The tip of the scope in the the apex, the balloon is inflated Counterclockwise torque will visualize the proximal CBD and clockwise torque and insertion will visualize the distal CBD There are four landmarks that one should look for. The “duodenal fall-off” “MP of the duodenum”, The CBD, The pancreatic duct and The portal vein. The second position Transducer is positioned directly perpendicular to the papilla. This is important in some cases with impacted CBD stones.

EUS performance in CBD stones In 1989, the first prospective and comparative blind study was published reporting the results of EUS in the diagnosis of CDB obstruction*. EUS is extremely accurate in diagnosing CBD stones with a Sensitivity of 95%, Specificity of 98% and An accuracy of 96% These results are far superior to US (sensitivity 63%) and CT (sensitivity 71%)(19) and were approximately equivalent to that of ERCP. *Amouyal. Lancet 1989; 2(8673):1195-1198.

EUS vs ERCP Several studies have compared EUS and ERCP in a blinded fashion. The sensitivity of ERC was found to be 79-90% compared to 88-100% for EUS with more false negative results with ERCP. ERCP false negatives were due to small stones located within dilated bile ducts EUS false negatives because of proximal CBD or IHD stones. Several additional advantages Gallbladder microlithiasis. Eliminate other obstructive pathologies such as small ampullary tumors, cholangiocarcinoma...

EUS vs ERCP Author Design # of pts Sen Sp accuracy Amouyal Prospective 62 97% 100% 98% Napoleon 58 90% 95% Shim 132 89% Palazzo Retrospective 422 96% Prat 119 93% Canto 64 84% 94% Kohut 134 Buscarini 485 99% Palazzo et al. GIE 1995; 42(3):225-231. Prat et al. Lancet 1996; 347(8994):75-79. Amouyal et al. Gastroenterology 1994; 106(4):1062-1067. Shim et al. Endoscopy 1995; 27(6):428-432. Buscarini et al. GIE 2003; 57(4):510-518.

Napoleon et al. Endoscopy 2003; 35(5):411-415. Limitations…. Cholangiography was used predominately as the reference standard for the presence or absence of stones Problem? stones, especially if small, may be missed by cholangiography. To overcome this problem, Napoleon followed, for at least 1 year, 238 patients who had initial normal EUS and found NPV of EUS was 95% Negative initial EUS should obviate the need for an ERCP in patients with suspicion of CBD stones. Napoleon et al. Endoscopy 2003; 35(5):411-415.

Aljebreen et al. GIE. 2006; 63 (5): AB274 EUS vs ERCP+ ES A prospective series of our first 60 patients who were referred for ERC for suspicion of choledocholithiasis All underwent radial EUS. EUS results were recorded as positive or negative for CBD stones before starting the ERC. Aljebreen et al. GIE. 2006; 63 (5): AB274

Aljebreen et al. GIE. 2006; 63 (5): AB274 Methodology All patients underwent ERC and sphincterotomy with basket or balloon sweep of the bile duct as the standard of reference for CBD stone. All procedures were performed during the same endoscopy session by a single endoscopiest who was blinded to the clinical, biochemical and imaging data. Aljebreen et al. GIE. 2006; 63 (5): AB274

Aljebreen et al. GIE. 2006; 63 (5): AB274 Results EUS diagnosed CBD stones in 24 patients (40%). 65% had low to moderate risk for CBD stones. EUS Total ERCP Positive Negative 23 1 24 3 33 36 26 34 60 Aljebreen et al. GIE. 2006; 63 (5): AB274

EUS Diagnostic performance Sensitivity: 89% (95% CI: 76-100) Specificity: 97% (95% CI: 91-100) Diagnostic accuracy: 93% (95% CI: 87-99)

Learning curve First 30 EUS procedures Last 30 EUS procedures Sensitivity 85 (95% CI: 65-100) 92 (95% CI: 78-100) Specificity 94 (95% CI: 83-100) 100 PPV (%) 92(95% CI: 76-100) NPV 89 (95% CI: 74-100) 94 (95% CI: 84-100) Accuracy 90% 97%

Conclusion of the study EUS is highly accurate for the diagnosis of choledocholithiasis. Tandem EUS and ERCP are relatively safe with no complications specifically attributable to performance of EUS. The EUS learning curve is relatively short for CBD stones. Aljebreen et al. GIE. 2006; 63 (5): AB274

EUS VS MRCP for CBD stones Author Study design # of pats MRC Sen MRC SP EUS Sen EUS Sp Ainsworth Prospective 163 87% 97% 90% 99% De Ledinghen 32 100% 73% 96% Materne 50 78% 98% 89% 95% Scheiman 28 40% 80% Kondo 88% 50% performance 301 85% 93% *Verma et al. GIE 2006; 64(2):248-254.

EUS or MRC for CBD stones? A systematic review* no significant differences between these modalities. Sensitivity of MRC in detecting stones above and below 5mm was 100% and 67% respectively**. When deciding between EUS and MRCP, clinicians should consider other factors, resource availability, experience, and costs. *Verma et al. GIE 2006; 64(2):248-254. **Kondo et al. Eur J Radiol 2005; 54(2):271-275.

Do benefits outweigh the costs? Cost-effectiveness of EUS in CBD stones depends on the risk of stones, stone-related symptoms and operator expertise. Expert IOC was the least costly for intermediate risk patients when risk of stones is between 17-34%, however, if expert EUS is available, 0-10% “low” risk of stones merits “expectant management”, 11-55% “intermediate risk” merits EUS; and > 55% “high risk” merits ERCP. Sahai et al. GIE 1999; 49(3 Pt 1):334-343.

EUS role acute biliary pancreatitis Prat et al suggested that rate of morbidity and mortality could be reduced by using systemically EUS in case of acute pancreatitis followed by ERC with sphincterotomy when EUS has demonstrated CBD stones. When compared the relative costs and outcomes of EUS and MRC to ERC in patients with acute biliary pancreatitis Romagnuolo found EUS significantly less costly than both ERC and MRC with fewer complications than ERC. Prat et al. GIE 2001; 54(6):724-729. Romagnuolo et al GIE 2005; 61(1):86-97.

CONCLUSIONS EUS combines the best performance and almost zero morbidity. EUS may be considered in lieu of ERCP as a diagnostic test for patients felt to have a low to intermediate risk of CBD stones. The main advantage of EUS over MRC its sensitivity and specificity for stones less than 5mm in size.

CONCLUSIONS The EUS learning curve is relatively short for CBD stones. Finally when EUS chosen as the imaging modality to identify CBD stones, it safe & logical to do ERCP during the same session.