Fragmentation Of Gallstones Research Articles

Gallstones: The thing in itself.

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S362 Endoscopic Holmium Laser Lithotripsy for Therapy of Bouveret Syndrome

Introduction: Bouveret syndrome is a rare condition characterized by the impaction of a gallstone in the stomach or duodenum via a fistulous tract resulting in gastric outlet obstruction. This condition generally requires surgery to remove the impacted stone. However, for patients who are unable to undergo surgery, laser lithotripsy can be an alternative therapy. Here, we present an interesting case of a patient with recurrent gallstone ileus successfully treated by endoscopic Holmium laser lithotripsy Case Description/Methods: A frail 79-year-old woman with chronic cholecystitis presented with right upper quadrant abdominal pain. Abdominal computed tomography (CT) scan demonstrated emphysematous calculous cholecystitis, a cholecystoduodenal fistula and a 30 mm gallstone lodged in the terminal ileum. She emergently underwent an ileocecal resection and partial right colectomy, confirming the diagnosis of gallstone ileus and a small bowel perforation. 10 days post-surgically, the patient again developed nausea, vomiting, and right upper quadrant pain. CT imaging re-demonstrated a 40 mm gallstone within the gallbladder fossa, Surgical options were limited due to a friable duodenum and inflammation of the cholecystoduodenal fistula. After a multidisciplinary discussion, endoscopic therapy was planned. Endoscopically, a large gallstone measuring about 40 mm was into the duodenal bulb eroding into the duodenum consistent with the known fistula. Holmium laser lithotripsy was used to fragment the stone. Due to the size of the gallstone, the procedure was performed in two sessions. During the first session, the stone was successfully fractured into smaller fragments. In the subsequent session, the remaining gallstone measuring about 28 mm was fragmented until the fistula tract was cleared. The larger gallstone fragments were removed using a roth net and a stone retrieval basket. Full resolution of the Bouveret syndrome was achieved. No immediate or delayed complications were noted. The patient is now doing well 3 months post-procedurally. (Figure) Discussion: Although surgery is often required for definitive therapy of Bouveret syndrome , endoscopic management remains a feasible option in select cases with appropriate expertise. Here, we present a case of successful endoscopic therapy utilizing Holmium laser lithotripsy in a high-risk patient for Bouveret syndrome. Although utilizing this technique is lengthy and requires advanced endoscopic expertise, provides a great benefit due to its minimal tissue injury and safety. Watch the video at https://tinyurl.com/ACGAbstractS362Figure 1.: A) Cholecystoduedenal fistula on CT scan, B) Holmium laser lithotripsy for Bouveret syndrome.

S1536 A Retained Gallstone Post-Cholecystectomy Presenting as Abdominal Pain and Bloody Diarrhea

Introduction: Retained gallstones is a complication of cholecystectomy which can lead to the formation of intra-abdominal abscesses. In the following case, we describe a patient who developed abdominal pain and bloody stools post-cholecystectomy, found to have a retained gallstone and abscess eroding into the liver parenchyma and colon. Case Description/Methods: A 69-year-old male with a past medical history significant for prostate cancer status post radiation and hormone therapy, hypertension, hyperlipidemia, and diabetes presented to the gastroenterology clinic for evaluation of bloody diarrhea and right lower quadrant abdominal pain of three weeks duration. He described the pain as constant and endorsed decreased appetite and three-pound weight loss over the same time period. Surgical history was significant for a laparoscopic cholecystectomy five months prior for gangrenous cholecystitis. A colonoscopy performed three years prior revealed radiation colonopathy and a tubular adenoma, but no other significant findings. Physical exam was unremarkable with no abdominal tenderness. Stool cultures and giardia were negative, and calprotectin was 8 mcg/g. Computed tomography of the abdomen and pelvis was subsequently performed, revealing a 3.5 × 2 cm peritoneal abscess with a 14 mm retained gallstone and gallstone fragments eroding into the liver parenchyma and the hepatic flexure of the colon. Given these findings, the patient was advised to present to the emergency department. He subsequently underwent a diagnostic laparoscopy with removal of the stone and drainage of the surrounding abscess. A Jackson Pratt drain was placed, and fluid cultures subsequently grew Escherichia coli. The patient was discharged with antibiotics on post-operative day two. On two-week follow up, the patient reported feeling well with complete resolution of his abdominal pain. Discussion: Gallstone spillage and subsequent abscess formation is a known risk of cholecystectomy. This most frequently occurs when laparoscopic cholecystectomy is complicated by gallbladder perforation. Symptoms of retained stones can present months to years after cholecystectomy. Definitive treatment generally requires both drainage of the abscess and removal of the retained gallstone to eliminate infection and prevent future repeat infection.Figure 1.: Computed tomography of the abdomen and pelvis (coronal view) demonstrating a 3.5 x 2 cm peritoneal abscess with a 14 mm retained gallstone (arrow) and gallstone fragments eroding into the liver parenchyma.

Bouveret’s syndrome: A case based review; clinical presentation, diagnostics and treatment approaches

Gastric outlet obstruction that arises from gallstones impacted in the distal stomach or proximal duodenum after passing through a cholecystoduodenal, cholecystogastric or rarely choledocoduodenal fistula is called as Bouveret’s syndrome and it accounts for approximately 1-3% of all the patients with gallstone ileus. Although treatment modalities, including stone removal or fragmentation with classical endoscopic devices, such as snares, and forceps or fragmentation of gallstones with new devices, such as electrohydraulic lithotripsy, laser, extracorporeal shockwave lithotripsy have been described. However, only 29% of the patients benefit from nonsurgical methods. Removal of the stone through a gastrotomy or enterotomy and performing cholecystectomy and fistula repair with a second operation is an approach recommended for older patients with comorbid diseases. In this paper, a case of Bouveret’s syndrome was presented. The authors also aimed to review the diagnosis, management and treatment of this rare disease and to update the previous reviews.

Biliary lithotripsy and what we learned from Carstensen

In the early 1990s, kidney-stone lithotripsy was a new burgeoning field and applications to gallstone destruction were being investigated. I came as the 1989-90 Hunt Fellow to work on the mechanisms of lithotripsy and related areas with Edwin Carstensen and his collaborators at the University of Rochester. The composition and liquid environment of gallstones is very different from that of kidney stones, however, and successful fragmentation of gallstones was rare. Comparing a Diasonics piezoelectric lithotripter and Dornier HM-3 lithotripter provided insights, as did studies of the mechanical and acoustical properties of gallstones. More generally, biliary lithotripsy led to fundamental studies of mechanisms of fragmentation and the interaction of acoustic shock waves outside and inside stones. While eventually the success of laproscopic surgery spelled the end of biliary lithotripsy as a competing technology, Ed Carstensen and his collaborators added knowledge that later paid dividends in related fields of biomedical acoustics, such as atherosclerotic plaque removal, sonothrombolysis, and cavitation-based imaging and therapy.

4:10 PM Abstract No. 108 - A new percutaneous pneumatic lithotripsy technique for common bile duct gallstones removal

Purpose To develop a new technique for percutaneous removal of common bile duct (CBD) gallstones by using a pneumatic lithotripter with a XCOIL encapsulator (XE) and retractor (XR) system. Materials and Methods For in-vitro confirmation, a 6.0mm glass tube was shaped to simulate the cystic duct and CBD of pigs. Human gallstone was placed into the tube. An 11Fr custom balloon introducer sheath (BIS) was positioned close to the gallstone, and then inflated to occlude the proximal tube. An XE and XR system was advanced through the BIS into the tube, to catch the gallstone by pulling XR back into the XE. The stone was restricted within the XE by closing the distal XE end via a string. A 1.0mm lithotripter probe was manually-curved according to the glass tube shape and then advanced into the XE through the BIS, where the gallstone was shocked. Fragments were then extracted from the tube with the XE. Lithotripsy procedures were repeated for 6 times. The shock numbers, the skin-to-skin lithotripsy time and fragment sizes were recorded. For in-vivo validation, via a transcystic approach, human gallstones were positioned into CBDs of three pigs through a 16Fr introducer. Under fluoroscopy, an 11Fr BIS was placed into CBD to break and remove the gallstones with the same procedures as developed from the in-vitro experiment. Pre- and post-cholangiographies were obtained to confirm the successes of the gallstone placement, breaking, and removal. After the experiment, the pigs were euthanized and CBDs were harvested for histology. Results Of the in-vitro experiment, average 9.5±4.2 shocks were required to break gallstones. The average skin-to-skin lithotripsy time was 6'10. All stones were successfully broken, with the average maximal length of the gallstone fragments at 2.1±0.3mm compared to the pre-lithotripsy stone length at 5.3±0.2 mm (p Conclusion The new XCOIL-assisted percutaneous pneumatic lithotripsy is feasible and safe for CBD gallstones breaking and removal, which establishes groundwork for its further clinical application.

Severe Acute Pancreatitis: A Rare Complication of Lithotripsy for Nephrolithiasis

Purpose: This is a 48-year-old male, admitted with severe pancreatitis after elective extracorporeal shock wave lithotripsy (ESWL) for kidney stones. His past history includes liver transplant 7 years ago for HCV and hepatocellular carcinoma. He also had recurrent HCV. He was clinically well, with no functional deficits until a few weeks prior to admission, when he developed new onset left flank pain and was noted to have 9-mm non-obstructing stone in left uretero-pelvic junction. He underwent elective ESWL as an outpatient. Within 24 hours post-lithotripsy he presented with severe abdominal pain with fever of 101 F, leukocytosis, and lipase of 7,600 U/ml (nl <56U/ml). Abdominal CT scan showed severe pancreatic edema and peri-pancreatic fluid collection suggesting acute pancreatitis. He has no past history of pancreatitis or gallstones but had an incidental finding of a 7-mm pancreatic body stone in the past. His hospital course was complicated with upper gastrointestinal bleeding, severe hypocalcemia, infected ascites, acute renal failure and delirium. When he deteriorated, he and his family opted to shift the goals of care to comfort measures only; he died on hospital day 12. The temporal association of the development of pancreatitis and ESWL treatment, in the absence of any other predisposing factors such as gallstones, alcohol abuse, hypercalcemia, hypertriglyceridemia, drugs, etc. supports a causal relationship in this patient. There has been rapid surge in the use of ESWL for renal stones due to its effectiveness and safety. However, ESWL has potential to have rare but severe complications. To our knowledge there are <5 cases of severe pancreatitis published in the literature. Hypotheses for the mechanism include inadvertent fragmentation of gallstones causing pancreatic duct obstruction, leakage of urine during ESWL or mechanical injury due to post-operative adhesions around pancreas. Although ESWL is very safe and effective for renal stones, serious complications can occur. Physicians should be mindful of these possible complications, to allow early detection and timely management.Figure: No Caption available.

Gallstone clearance: A randomized study of extracorporeal shock wave lithotripsy and chemical dissolution

Following extracorporeal shock wave lithotripsy it is not known whether gallstone fragments are cleared from the gallbladder without the use of oral dissolution therapy. To assess the efficacy of lithotripsy and dissolution therapy, alone or in combination, 35 patients were randomized to one of three treatment groups: lithotripsy alone, dissolution therapy alone or combined lithotripsy and dissolution therapy. All patients had symptomatic gallstones, functioning gallbladders and comparable stone profiles. Lithotripsy was administered using a piezoelectric lithotripter. Dissolution therapy consisted of combined bile acid and terpene. Clearance was assessed at 6 months using ultrasound and oral cholecystography. Patients with less than 50 per cent stone clearance at the end of 6 months were considered failures. The number of patients with total or partial clearance in the combined group (7/10) was significantly greater than those in the lithotripsy alone group (0/10, P less than 0.002). Gallstone clearance following lithotripsy appears to be dependent upon dissolution therapy.

Gallstone clearance: A randomized study of extracorporeal shock wave lithotripsy and chemical dissolution

Following extracorporeal shock wave lithotripsy it is not known whether gallstone fragments are cleared from the gallbladder without the use of oral dissolution therapy. To assess the efficacy of lithotripsy and dissolution therapy, alone or in combination, 35 patients were randomized to one of three treatment groups: lithotripsy alone, dissolution therapy alone or combined lithotripsy and dissolution therapy. All patients had symptomatic gallstones, functioning gallbladders and comparable stone profiles. Lithotripsy was administered using a piezoelectric lithotripter. Dissolution therapy consisted of combined bile acid and terpene. Clearance was assessed at 6 months using ultrasound and oral cholecystography. Patients with less than 50 per cent stone clearance at the end of 6 months were considered failures. The number of patients with total or partial clearance in the combined group (7/10) was significantly greater than those in the lithotripsy alone group (0/10, P less than 0.002). Gallstone clearance following lithotripsy appears to be dependent upon dissolution therapy.

Apolipoprotein E polymorphism and lithogenic factors in gallbladder bile.

Associations between the polymorphism of apolipoprotein E, which plays an important role in cholesterol metabolism and cholesterol gallstone formation, have been reported recently. Patients with the apo E4 isoform showed increased numbers and cholesterol contents of their stones, a higher frequency of cholesterol crystals in bile, increased susceptibility to gallstone fragmentation by extracorporeal shock-wave lithotripsy and an increase in recurrence rate after dissolution. A recent study, however, showed that fast cholesterol crystallization in bile is associated with multiple stones but not with apo E4. Therefore the mechanism for an increased risk of gallstone formation in patients with the apo E4 isoform still remains under debate. To clarify this issue we investigated 37 patients with gallstones (10 with the apo E4 allele and 27 without the allele). Gallbladder biles were examined for total cholesterol and other lipids, cholesterol saturation index, crystal observation time, crystal mass, total protein and mucin. Moreover, number of gallstones and cholesterol in gallstones was compared in both groups. The crystal observation time (2.5 vs. 2.0 days, median) and the cholesterol saturation index (1.34 +/- 0.45 vs. 1.43 +/- 0.74) did not differ significantly between the apo E4 and the non apo E4 group. Total biliary lipids (11.6 +/- 3.8 vs. 9.3 +/- 3.9 g 100 mL-1, P = 0.126) and total biliary cholesterol (21.8 +/- 9.7 vs. 15.7 +/- 7 mmol L-1, P = 0.067) tended to be elevated in the apo E4 group. Crystal mass (3.60 +/- 4.10 vs. 2.38 +/- 2.70 mmol L-1), biliary total protein (8.6 +/- 3.5 vs. 8.3 +/- 6.6 mg mL-1) and mucin (0.55 +/- 0.38 vs. 0.66 +/- 0.67 mg mL-1), number (solitary/multiple) of gallstones and cholesterol in gallstones were not different in both groups of patients. In comparison to the non apo E4 patients the apo E4 group showed a trend to elevated biliary cholesterol whereas crystal observation time, cholesterol saturation index, crystal mass, number of gallstones, cholesterol content of gallstones and total protein and mucin were not different. These findings do not suggest an association of the apo E isoform and the formation of cholesterol gallstones

An electromagnetic generator of focused shock waves with a coaxial radiator excited by the axial current

The device hereafter described forms focused acoustic pressure pulses excited by a pulsed magnetic field affecting a cylindrical shell. A specific feature of the instrument is its coaxial radiator connected to a capacitive storage through a pulse transformer with a single-turn secondary winding that is used to excite the acoustic pulse. Design versions of the coaxial radiator are considered and estimates for setting design parameters are presented along with the test results obtained on a prototype model. The device can be used in shock-wave medical apparatuses for fragmentation of nephroliths and gall-stones.

Unusual abscess patterns following dropped gallstones during laparoscopic cholecystectomy

Laparoscopic cholecystectomy has become the standard treatment for symptomatic cholelithiasis. Numerous clinical trials have deemed it a safe procedure, regardless of the known increased risk of bile duct injury. However, the consequences and incidence of less well-known complications are still being addressed. Between 1993 and 1995, 1,130 laparoscopic cholecystectomies were performed at two major metropolitan medical centers. Of these patients, we know of 3 (0.3%) who subsequently developed abscesses as a consequence of dropped stones during the laparoscopic cholecystectomy. One additional patient who underwent prior laparoscopic cholecystectomy at another institution developed late infection as well. All 4 patients developed late purulent abscesses that ultimately required open surgical drainage, and 1 patient developed trocar site "tumor" masses that were secondary to inflammatory tissue around gallstone fragments. All patients were successfully treated by surgical drainage, stone removal, and antibiotics. Trocar site inflammatory masses required excision only. Significant costs were involved in the diagnosis, management, and duration of therapy for these problems. This experience closely resembles that of other centers and points out the existence of a late postoperative complication following laparoscopic cholecystectomy that was rarely encountered with open cholecystectomy. Strategies for avoiding this problem are discussed. Whether dropped stones are an indication for conversion to open cholecystectomy remains unclear. Thorough irrigation at time of laparoscopic cholecystectomy with or without placement of a drain in the subhepatic space does not prevent this complication.

Physical laws of cholesterol gallstone fragmentation.

Efficient fragmentation is the most important prerequisite for successful treatment of gallstones by extracorporeally induced shock waves. No data are available on the amount of energy necessary for stone disintegration and on the threshold energy below which no further fragmentation occurs. We therefore performed an in vitro investigation on human cholesterol gallstones to elucidate physical laws governing shock-wave lithotripsy. First, the focal pressure of the lithotripter was measured to calculate the energy traversing a stone. Second, 96 gallstones from 16 gall bladders were analysed with respect to physicochemical composition, radiological features and ultrasound before fragmentation was performed. Energy for stone disintegration was constant within each stone family but varied between 4.6 mL-1 and 36.8J mL-1 in different families. This energy correlated linearly with stone volume. None of the radiological and physicochemical factors revealed a clear-cut correlation of the different energies necessary for similar stone disintegration. The threshold energy differed between 0.26 mJ and 1.04 mJ per pulse. In conclusion, stone volume was the best parameter predicting stone fragmentation. However, in cholesterol stones with a similar composition the required energy per volume varies considerably together with the threshold energy. Radiological and ultrasound parameters appear to be of minor importance in explaining these differences.

Minimal static excess pressure minimises the effect of extracorporeal shock waves on cells and reduces it on gallstones

The effects of extracorporeal shock waves on haemoglobin release, membrane permeabilisation and stone fragmentation were examined at minimal static excess pressures. Shock waves from an electrohydraulic lithotripter were applied at 15, 20 and 25 kV to red blood cells in plastic pipettes pressurised with 0, 30, 50, 75, 100, 200, 300 and 400 kPa of static excess pressure; the freed haemoglobin was determined as a marker of cell destruction. Using 15-kV discharges, 30-kPa excess pressure reduced the freed haemoglobin from 1.21 g/L at ambient pressure to 0.39 g/L, 20-kV discharges reduced it from 2.01 g/L to 0.92 g/L and 25-kV discharges from 2.56 g/L to 1.61 g/L. Haemoglobin values at 400-kPa excess pressure were reduced to 0.03 g/L (15-kV discharges), 0.07 g/L (20-kV discharges) and 0.09 g/L (25-kV discharges), which is a 95%–97% reduction of the values obtained at ambient pressure. There was a steep initial drop from 30–100 kPa excess pressure followed by a plateau at low level. Propidium iodide uptake by L1210 tumour cells, a marker for transient membrane permeabilisation by shock waves, was reduced by 90% at these slight excess pressures. Stone fragmentation was also suppressed by excess pressure yet not as markedly as at cells; 100 kPa reduced the amount of gallstone fragments by 20%, and 400 kPa reduced it by 65%. A further reduction, by 93%, was obtained when 1-MPa excess pressure was applied to gallstones in a Plexiglas cylinder. Shock wave-gas bubble interaction has been previously proposed to mediate the shock wave action. It is suggested that the excess pressure reduced the size or number of the bubbles, thus reducing this interaction, at least in the case of the cellular effects. The reduced effect of shock waves on cells, in contrast to the effect on stones, might open up a new approach to the design of lithotripters that would reduce tissue damage yet keep fragmentation up at a similar level.

Enhanced fragmentation of fractured gall-stones with contact lithotripsy

SummaryGall-stone fragmentation is mainly a function of the physical characteristics of both the administered shock waves and the gall-stones. Geometrical irregularities, such as holes and cracks, have previously been shown to reduce the local stress required to break solid structures. We therefore tested the hypothesis that contact lithotripsy would fragment fractured gall-stone sooner than intact gall-stones. Fifty-four gall-stones harvested from 18 consecutive cholecystectomy patients were randomized into three groups. Group A included gall-stones which were drilled by a diamond-tipped knife creating a small crater in the stone surface. Group B were sister stones from the same gall bladder used as controls. A third stone from the same patient was used for chemical analysis. All stones were fragmented by ultrasonic contact lithotripsy using a Wolf Lithotrite at 100% power and at a frequency of 10 shock waves per s. Fragmentation time for drilled stones was 27 ± 6 s compared to 71 ± 13 s for nondrilled stones (P lt; 0.001). There was no correlation between chemical analysis and time to stone fragmentation. We conclude that fracturing of stones prior to lithotripsy reduces fragmentation time, and may thus increase the efficacy and safety of contact lithotripsy of both gall-stones and common bile duct stones.

Gallstone Recurrence and Gallbladder Function Following Percutaneous Cholecystolithotomy

To determine the frequency of recurrent symptoms and gallstones following successful percutaneous cholecystolithotomy (PCCL) and to evaluate the effect of the procedure on gallbladder function. Between 1988 and 1991, 32 patients underwent successful PCCL for the treatment of symptomatic gallstones. Outcome was assessed clinically (mean follow-up, 24 months) in 31 patients and by means of serial ultrasound examination (mean follow-up, 26 months) in 23 patients. Symptomatic relief following the procedure was good, with only five of 31 patients (16%) experiencing recurrent symptoms during the follow-up period. Eight patients died of unrelated causes with no recurrence of symptoms. Nine (39%) of the remaining 23 patients have either retained gallstone fragments (four patients [16%]) or recurrent gallstones (five patients [22%]). Gallbladder motility was studied after PCCL in 10 patients, including four with retained or recurrent stones, and nine gallbladders were shown to be functioning well. PCCL is a useful treatment for symptomatic gallstones in patients at high risk for surgery. It preserves gallbladder function, but recurrent gallstones are a significant problem.

In vitro study to elucidate the physical laws concerning the fragmentation of both solitary and multiple artificial stones

These in vitro studies define the basic physical laws regarding work and energy for the successful fragmentation of human gallstones. For this purpose a standardized stone model was used consisting of plaster and glass microspheres with physical properties similar to those of human gallstones. All experiments were performed using the lithotripter model MPL9000 (Dornier). The acoustic energy passing stones of 10-30 mm ranged between 8 and 90 mJ per pulse depending on the stone size and energy setting. These results represent the basis for the three following investigations. In the first experiment the relationship between fragmentation and shock wave energy was investigated in a basket with 2 mm mesh size. Thus no layer of small fragments could shadow the acoustic energy for further fragmentation of larger fragments. A constant amount of stone material was found to be fragmented per shock-wave pulse irrespective of stone volume. A low energy threshold (2 mJ/cm3) was observed, below which fragmentation did not occur. In the second experiment, the sieve was covered with a membrane, thus simulating the in vivo situation. The presence of a layer of small fragments hindered the further disintegration of the larger fragments. The attenuation depended to a large extent on original stone volume and acoustic energy per pulse. The corresponding attenuation factor increased with the original stone volume. Thus the fragmentation of a stone with a diameter of 30 mm was attenuated twice as much as a stone of 20 mm size. The critical layer thickness at which no further disintegration took place was 2.5 mm at 18 kV, 4.2 mm at 22 kV, and 5.0 mm at 26 kV.(ABSTRACT TRUNCATED AT 250 WORDS)

Transient acoustic cavitation in gallstone fragmentation: a study of gallstones fragmented in vivo.

The mechanism of gallstone fragmentation by shock waves in vivo is uncertain. We used scanning electron microscopy to study 9 partially fragmented stones obtained from 6 patients who underwent lithotripsy and subsequently had surgery because of incomplete fragmentation. Surface characteristics of the stone were studied using scanning electron microscopy and compared to gallstones fragmented in degassed water in vitro and to control stones obtained from patients with uncomplicated cholelithiasis. Characteristic damage caused by transient acoustic cavitation was visible in all stones fragmented in vivo and in vitro as pits 10-100 microns diameter. In these pits, cholesterol crystals were fractured, and the symmetry of crystal boundaries was damaged. In areas of more severe damage, individual pits coalesced to form craters on the stone surface. High magnification of the pit walls revealed cracks, which in some instances radiated out onto the unpitted surface of the stone. We conclude that transient acoustic cavitation plays a role in gallstone fragmentation in vivo through the mechanism of surface pitting and the formation of cracks that radiate outward from the surface pits. Measures to enhance cavitation may improve the results of gallstone lithotripsy.

In Vitro Fragmentation of Gallstones with Lithotriptors for Use in Laparoscopic Cholecystotomy

In preliminary in vitro experiments, five different lithotriptors for use in laparoscopic cholecystotomy were tested to determine the fragmentation time and rate of a defined group of gallstones. The Alexandrit laser and the ultrasonic lithotriptor were too ineffective to warrant further investigation. In phantom tests with pig gallbladders, the pulsed dye laser and the electrohydraulic lithotriptor had a fragmentation rate of 100%, but the rate of clearing of the gallbladder was 0% as stone debris always remained in the gallbladder. The clearing rate of the RotoLith mechanical lithotriptor was 84.6%. The RotoLith lithotriptor was the most effective device because the stones were ground into such small particles that they could easily be rinsed out of the gallbladder. As the RotoLith procedure does not need to be monitored optically, the opening of the gallbladder need not exceed 3 mm compared to 10 mm for the other lithotriptors. This makes closure of the gallbladder safer and it would seem feasible to perform the procedure using the RothoLith lithotriptor under local anaesthesia.

Gallstone Lithotripsy: In Vitro Comparison of Fragmentation with a Tunable-Dye Laser and an Ultrasonic Wire

Large bile duct stones require fragmentation prior to extraction through the papilla or through a percutaneous tract. This can be attempted with dissolution therapy, crushing baskets, or lithotripsy. Lithotripsy can be accomplished safely and effectively with tunable-dye laser energy delivered through a flexible, 1-F optical fiber under endoscopic or fluoroscopic guidance, but laser technology is very costly. A prototype, flexible ball-tipped wire coupled to an ultrasonic generator via a piezoelectric crystal has been developed for sonolysis of atheroma and thrombus in humans. The purpose of this experiment was to compare human gallstone fragmentation in vitro with a tunable-dye laser and this prototype wire to see if the less expensive ultrasound device might provide an alternative to costly laser technology. Gallstones from 17 patients were subjected to lithotripsy in a water bath with each device until completely fragmented or 60 seconds had elapsed. Neither device effectively fragmented cholesterol stones under these conditions. The ultrasonic wire completely fragmented 57% of bilirubinate stones in 60 seconds. The tunable-dye laser completely fragmented 100% of bilirubinate stones in less than 35 seconds (P = .04). Tunable-dye laser lithotripsy appears superior to the ultrasonic device for percutaneous treatment of bile duct stones.