2.2 Role of Pre-endotherapy Extracorporeal Shockwa...
ESWL should be performed for patients who have stones that are more than 5 mm in diameter.With successful ESWL，aiming for pulverisation of stones to granular powder form，complete ductal clearance rates would be improved.The lithotriptor machines frequently used for ESWL of renal stones are also used for pancreatic ductal stones.Commonly used settings include shockwaves of up to a maximum of 5000 shocks per session，at an intensity of 5-6（15,000-16,000 kv）on a scale of 1-6，with a frequency of 90-100 shocks/min（Tandan et al.2010；Hu et al.2015）.Patients usually require sedation and analgesia during the procedure；at our unit，patients are given patientcontrolled analgesia using intravenous fentanyl.An experienced ESWL technician will be able to localise and target the radio-opaque pancreatic ductal stones for effective fragmentation in about 90%of patients，with the majority requiring less than three sessions（Tandan et al.2010；Nguyen-Tang and Dumonceau 2010）.(https://www.daowen.com)
Although generally well-tolerated，complications of ESWL include skin ecchymosis and pain（Tandan et al.2010）.A large series showed an overall post-ESWL complication rate of 6.7%，with pancreatitis being the most common（4.4%）（Li et al.2014）.Other complications include infection，steinstrasse，perforation，bleeding and pancreatic fistula.Steinstrasse or“stone street”presents with an acute abdominal pain secondary to stone fragments incarceration at the major papilla，causing pancreatic drainage obstruction.This may occur in up to 1%of patients（Hu et al.2015）.