Extracorporeal shock wave lithotripsy for pancreatic and large common bile duct stones

Abstract

Extraction of large pancreatic and common bile duct (CBD) calculi has always challenged the therapeutic endoscopist. Extracorporeal shockwave lithotripsy (ESWL) is an excellent tool for patients with large pancreatic and CBD calculi that are not amenable to routine endotherapy. Pancreatic calculi in the head and body are targeted by ESWL, with an aim to fragment them to < 3 mm diameter so that they can be extracted by subsequent endoscopic retrograde cholangiopancreatography (ERCP). In our experience, complete clearance of the pancreatic duct was achieved in 76% and partial clearance in 17% of 1006 patients. Short-term pain relief with reduction in the number of analgesics ingested was seen in 84% of these patients. For large CBD calculi, a nasobiliary tube is placed to help target the calculi, as well as bathe the calculi in saline - a simple maneuver which helps to facilitate fragmentation. The aim is to fragment calculi to < 5 mm size and clear the same during ERCP. Complete clearance of the CBD was achieved in 84.4% of and partial clearance in 12.3% of 283 patients. More than 90% of the patients with pancreatic and biliary calculi needed three or fewer sessions of ESWL with 5000 shocks being delivered at each session. The use of epidural anesthesia helped in reducing patient movement. This, together with the better focus achieved with newer third-generation lithotripters, prevents collateral tissue damage and minimizes the complications. Complications in our experience with nearly 1300 patients were minimal, and no extension of hospital stay was required. Similar rates of clearance of pancreatic and biliary calculi with minimal adverse effects have been reported from the centers where ESWL is performed regularly. In view of its high efficiency, non-invasive nature and low complication rates, ESWL can be offered as the first-line therapy for selected patients with large pancreatic and CBD calculi.

Keywords: Common bile duct calculi; Extracorporeal shockwave lithotripsy; Pancreatic calculi.

Figures

Figure 1

Principle of extracorporeal shockwave lithotripsy. Shockwaves from the source are targeted on the calculi and these induce fragmentation.

Figure 2

Protocol followed at Asian Institute of Gastroenterology, for extracorporeal shockwave lithotripsy of large pancreatic duct calculi[7]. EPS: Endoscopic pancreatic sphincterotomy; US: Ultrasound; EUS: Endoscopic ultrasound; MRCP: Magnetic resonance cholangiopancreatography; ERCP: Endoscopic retrograde cholangiopancreatography; PD: Pancreatic duct; ESWL: Extracorporeal shock wave lithotripsy; NPT: Naso-pancreatic tube.

Figure 3

Third-generation lithotripter with fluoroscopic and ultrasound imaging facility.

Figure 4

Large pancreatic calculi in head and genu, cleared by extracorporeal shockwave lithotripsy followed by pancreatic stenting. ESWL: Extracorporeal shockwave lithotripsy.

Figure 5

Large pancreatic calculi in head. Post extracorporeal shockwave lithotripsy (ESWL) reduction in diameter of main pancreatic duct.

Figure 6

Protocol for extracorporeal shockwave lithotripsy of large common bile duct calculi. CBD: Common bile duct; ERCP: Endoscopic retrograde cholangiopancreatography; NBT: Nasobiliary tube; ESWL: Extracorporeal shockwave lithotripsy.

Figure 7

Large common bile duct calculi with narrow distal common bile duct. Good fragmentation achieved with extracorporeal shockwave lithotripsy (ESWL).