Manzoor U. et al., 2020: Safety and Efficacy of Extracorporeal Shock Wave Lithotripsy for Difficult-to-retrieve Common Bile Duct Stones: A Ten-year Experience
Background and objective: Extracorporeal shock wave lithotripsy (ESWL) for common bile duct (CBD) stones has been used in the past, but experience is limited. We report our experience of ESWL in the management of difficult CBD stones.
Methods: Patients with difficult-to-retrieve CBD stones were enrolled and underwent ESWL. Fluoroscopy is used to target the stones after injection of contrast via nasobiliary drain. CBD clearance was the main outcome of the study.
Results: Eighty-three patients were included (mean age 50.5 ± 14.5 years); these patients were mainly females (43; 51.8%). Large stones >15 mm were noted in 64 (77.1%), CBD stricture in 22 (26.5%) and incarcerated stone in 8 (9.6%) patients. Patients needed 2.1 ± 1.2 sessions of lithotripsy and 4266 ± 1881 shock waves per session. In 75 (90.3%) patients, the fragments were extracted endoscopically after ESWL, while spontaneous passage was observed in 8 (9.6%). Total CBD clearance was achieved in 67 (80.6%) patients, partial clearance in 5 (6%) and no response in 11 (13.2%). Failure of the treatment was observed in large stone with size ≥2 cm (P = 0.021), incarcerated stone (P = 0.020) and pre-endoscopic retrograde cholangiopancreatography cholangitis (P = 0.047).
Conclusion: ESWL is a noninvasive, safe and effective therapeutic alternative to electrohydraulic lithotripsy and surgical exploration for difficult biliary stones.
J Transl Int Med. 2020 Sep 25;8(3):159-164. doi: 10.2478/jtim-2020-0025. eCollection 2020 Sep. PMID: 33062592. FREE ARTICLE
It is interesting to note that SWL has maintained a place as a valuable tool for removal of difficult bile duct stones. There are several reasons for that: Firstly, a non-invasive or non-surgical procedure might be necessary for these very often old and brittle patients. Secondly, when endoscopic methods have failed, demanding open surgery was the only alternative if SWL had not demonstrated its capacity to deal with this delicate matter.
One of the problems with bile duct stones is that most of them are radiolucent. This contrasts with pancreatic stones, most of which are composed of calcium carbonate. Bile duct stones therefore must be visualized by contrast infusion, either via a naso-biliary catheter or T-tube. Occasionally a stent might be used as a guide for indirectly localization of the stone.
In the current article the authors present their experience of 83 patients treated for bile duct stones with SWL. Large stones, bile duct strictures and incarcerated stones were the indications. All treatments were carried out with a Modulith SLX lithotripter with the patients in prone position and with a naso-biliary catheter in place. The mean (SD) age of the patients was 50.5 (14.5) years. In my opinion younger than expected. The treatment failed in 11 cases whereas successful complete clearance was recorded in 67 (81%). In the remaining 5 patients, partial clearance was achieved. For this result it was necessary with 2.1(1.2) sessions with an average of 4266 shockwaves administered per session. Failed treatment occurred when the stones were larger than 2 cm.
My personal experience with SWL of bile duct stones dates to 1988. For treatment of such stones, we used the unmodified Dornier HM3 lithotripter (one patient was treated with MPL9000). In a report from 1992  we summarized the results obtained in 28 patients with common bile duct stones and 9 with intra-hepatic stones. 82% of the patients with common bile duct stones became stone-free. The corresponding result for intra-hepatic stones was 67%. In 32% of the patients, stone fragments passed spontaneously whereas endoscopic removal (ERCP) cleared the system in another 50%. The patients in our study were older than those in the current report. For common bile-duct stones the mean age was 82 years (47-96) and for intra-hepatic stones 54 years (34-74). All 9 intra-hepatic stones were given one SWL session. For the 28 patients with common bile-duct stones 36 sessions were carried out; that is 1.3 sessions per patient. It is of note that none of the patients required general anaesthesia!!
Subsequently, there also has been successful SWL of complicated stones with Storz Modulith SLX lithotripter.
In summary, the current as well as older treatment results clearly show that when other low-invasive treatment results have failed, SWL remains as an excellent tool for removal of stones from the common bile duct as well as from hepatic ducts.
1.Lindström E, Borck K, Kullman P, Tiselus HG, Ihse I. Extracorporeal shock wave lithotripsy of bile duct stones: a single institution experience. Gut 1992;33:1416-1420