**3. ESWL for common bile duct (CBD) stones**

**1. Introduction**

Shock waves are single high amplitude sound waves produced by electrohydraulic, piezoelec‐ tric or electromagnetic methods that are transmitted into tissues with sudden rise from low pressure to its highest pressure at wave front followed by lower tensile amplitude [1]. The international society for medical shock wave treatment [2] defines shock waves as sonic pulse characterized by high peak pressure (500 bar), short life cycle (10 ms), fast pressure rise (<10 ns) and a wide frequency spectrum. The shock waves are condensed at a zone of highest energy concentration in the targeted area within the treated tissues. The most important effects of shock waves are reflection with pressure and tension powers at levels of different resistance and the production of cavitation bubbles in liquids. These bubbles collapse and produce local shear forces by high velocity liquid streams (so‐called jet stream) [1, 3, 4]. The introduction of ESWL during the early 1980s markedly changed the management of urinary tract stones, and during the last two decades, the development of new techniques of ESWL has changed completely the way of treatment of patients with renal stones [5]. ESWL was first successfully used in children in 1986 [6], and now, it is the first‐line treatment of pediatric renal stones [7, 8]. Urolithiasis is not the only application for extracorporeal shock waves, but there are also other applications for it. Extracorporeal shock wave is used for the treatment of gall bladder stones [9], common bile duct stone clearance [10], pancreatic calculi [11, 12], salivary stones [13, 14], erectile dysfunction

110 Updates and Advances in Nephrolithiasis - Pathophysiology, Genetics, and Treatment Modalities

[15, 16], refractory angina pectoris [17, 18], and chronic wound healing [19, 20].

When ESWL was first used for gall stone lithotripsy, it was combined with bile acid ther‐ apy, which was only effective against non‐calcified cholesterol stones. That is the reason why ESWL was only used against these types of stones [9]. However, some recent studies have proven that ESWL combined with bile acid therapy showed no significant improvement in

Being minimally invasive, ESWL was preferred by patients and doctors to be used for gall stone clearance in contrast to surgery. However, cholecystectomy has proven less recurrence

On the other hand, a randomized, prospective study by Nicholl et al. [23] stated that both ESWL and CC groups had similar results regarding the 1‐year health status following treat‐ ment. Moreover, the ESWL group health status was improved within 2 weeks in contrast to

The lack of sufficient studies for the optimal application of ESWL in patients with gall stones hindered the Food and Drug Administration (FDA) approval for its use for gall stone lithotripsy.

**2. ESWL in treatment of gallstones**

gall stone clearance in comparison to ESWL alone [21, 22].

rates for gall stone development than ESWL [9].

that of CC group that was improved in 5 weeks.

**2.2. Future of ESWL in gall stones treatment**

**2.1. Efficiency of ESWL in comparison with cholecystectomy (CC)**

Several studies reported the use of extracorporeal shockwave lithotripsy for common bile duct stones. As an instance, Tandan and Reddy [10] applied a certain protocol using ESWL for large CBD stones in their institute (Asian Institute of Gastroenterology, India). This protocol stated the start with endoscopic retrograde cholangiopancreatography (ERCP) as an initial procedure with placement of a nasobiliary tube to opacity the calculi to bath them in saline and to facilitate their targeting. This was followed by ESWL till the calculi were fragmented to a diameter less than 5 cm. Finally, ERCP is performed using a balloon or a basket to clear the CBD, and stenting was done only if indicated.

ESWL was indicated in all cases with large CBD stones with failure of their extraction by using the routine techniques; sphincterotomy followed by basket or balloon traw [10].

Tandan and Reddy reported some complications following the use of ESWL, including skin ecchymosis, pain at the site of administration, abdominal pain, occasional fever and hemato‐ bilia [10].

These complications can be reduced using a third‐generation lithotripter with more accurate targeting and reduced patients' movements [24, 25].
