Dec 5, 1988 - From the University of Florida College of Medicine,. Gainesville ...... common bile duct calculiusing ultrasound, but this tech- nology has only .... David Fletcher, a surgeon at the Austin Hospital at Melbourne, who says that ...
Extracorporeal Shock-Wave Lithotripsy of Bile Duct Calculi An Interim Report of the Dornier U.S. Bile Duct Lithotripsy Prospective Study
Principle Investigators: KIRBY 1. BLAND, M.D.,* R. SCOTT JONES, M.D.,t JAMES W. MAHER, M.D.,4 PETER B. COTTON, M.D.,11 TIMOTHY C. PENNELL, M.D., J. RICHARD AMERSON, M.D.,# J. LAWRENCE MUNSON, M.D.,** GEORGE BERCI, M.D.,ttGERHARD J. FUCHS, M.D.,4 LAWRENCE W. WAY, M.D.,""11 JOHN B. GRAHAM, M.D.,¶ BERNARD U. LINDENAU,## FRANK G. MOODY, M.D.*** Coinvestigators: ROBERT C. NEWMAN, M.D., BIRDWELL FINLAYSON, M.D., PH.D., EDWARD M. COPELAND III, M.D., NIKOLAUS GRAVENSTEIN, M.D., IRVIN F. HAWKINS, JR., M.D., MICHAEL P. HOCKING, M.D., ISAAC KALVARIA, M.D., CHARLES E. KING, JR., M.D., PABLO R. ROS, M.D., STEPHEN B. VOGEL, M.D.,* JAY Y. GILLENWATER, M.D., RICHARD W. MCCALLUM, M.D., CHARLES J. TEGTMEYER, M.D.,t FRED JOHLIN, M.D., STEFEN LOENING, M.D., ROBERT SUMMERS, M.D.,4 JOHN WEINERTH, M.D.,"1 DAVID L. MCCULLOUGH, M.D., DAVID GELFAND, M.D., JOHN GILLIAM, M.D., RICHARD T. MYERS, M.D., DOUGLAS WOLF, M.D., SAM AMBROSE, M.D.,# RICARDO ROSSI, M.D.,** JOEL PANISH, M.D.,tt AARON FINK, M.D., RONALD TOMPKINS, M.D.,4 ROY GORDON, M.D., ERNEST RING, M.D., HOWARD SHAPIRO, M.D.,""11 ROBERT CRAIGS, M.D., and DAVID NAHRWOLD, M.D.1¶
A multi-institutional study to evaluate the efficacy, clinical application, and safety of extracorporeal shock-wave lithotripsy (ESWL) with the Dornier HM-3 or HM-4 lithotripter for bile duct calculi (BDC) was initiated in September, 1987. Symptomatic patients who entered into this prospective trial had BDC in the common bile duct and/or the intrahepatic, cystic or lobar ducts of the liver that were inaccessible or untreatable by papillotomy or percutaneous stone extraction. The study excluded gallbladder stones. Nasobiliary (54.4%) or transhepatic catheters (10.5%) and T-tube or cholecystostomy tubes (17.5%) or combinations (14.0%) permitted access for radiographic contrast to allow fluoroscopic monitoring of stone position and fragmentation. Exclusion criteria included pregnancy, failure to localize the stone, disturbances of coagulation, pacemakers, or vascular aneurysms or large bones that lie in the focal axis of the shock waves. Eleven institutions treated 42 patients (23 male, 19 female) with BDC; age range was 25 to 95 years (mean ± SD, 73.5 ± 13.8) and ASA risk category was 1 to 4 (mean, 2.3 ± 0.8). Fourteen patients (333%) had a single BDC; 28 had 2 to 8 stones (mean, 2.7 ± 1.8) ranging in size from 6 mm to 30 mm (mean, 18.5 ± 6.4). The majority (66.7%) of patients were postcholecystectomy. The 42 patients received 57 ESWL treatments consisting of 600 to 2400 shocks per treatment (mean, 1924 ± 289) at 12 to 22 kV (mean, 18.5 ± 1.9) administered over 20 to 125 minutes (mean, 52.9 ± 20.8). General anesthesia was used in 32% of the treatments; the majority were treated with epidural or regional block (42.1%), local infiltration (28.1%), or intravenous sedation (38.6%). Fifteen patients (35.7%) required two ESWL treatments. Stone fragmentation occurred in 94.6% of Presented at the 100th Annual Meeting of The Southern Surgical Association, Boca Raton, Florida, December 5-7, 1988. Correspondence and reprint requests to: Kirby I. Bland, M.D., Department of Surgery, Box J-286, University of Florida, College of Medicine, Gainesville, Florida 32610.
From the University of Florida College of Medicine, Gainesville, Florida *; University of Virginia Medical Center, Charlottesville, Virginiat; University of Iowa, Iowa City, lowat; Duke University Medical Center, Durham, North Carolinall; Bowman-Gray School of Medicine, WinstonSalem, North Carolina¶; Emory Clinic, Atlanta, Georgia#; Lahey Clinic, Burlington, Massachusetts * *; Cedars Sinai Medical Center, Los Angeles, Californiatt; University of California, Los Angelestt; University of California, San Franciscolill; Northwestern Memorial, Evanston, Illinoisl¶; Dornier Medizintechnik GmbH, Munich, West Germany##; University of Texas, Houston, Texas ***
evaluable patients and in 90.4% of ESWL treatments, respectively; however, BDC fragments remained in 59.5% of patients 24 hours after treatment (diameter < 3 mm, 12%; 4 to 9 mm, 16%; 2 10 mm, 68%). Some patients (50%) required adjunctive procedures to achieve stone removal that included endoscopic extraction (n = 10; 47.6%), biliary lavage (n = 8; 38.1%), endoscopic bile duct prosthesis (n = 1; 4.8%), and operation (n = 2; 9.5%). ESWL treatment complications during hospitalization were observed in 15 patients (35.7%) and were present in four (9.5%) at discharge. Complications included macrohematuria (5%), biliary pain (15%), biliary sepsis (5%), hemobilia (10%), ileus (2.5%), and adverse pulmonary changes (7.5%). One patient developed pancreatitis before ESWL at ERCP that resolved prior to discharge. At discharge, 73.8% of patients were stone free. This interim report suggests that ESWL successfully fragmented BDC and, with the adjunctive techniques used in one half of the patient population, resulted in the elimination of stones from three fourths of treated patients at the time of hospital discharge. ESWL permitted successful elimination of BDC with moderate rates of morbidity and no deaths for these high-risk patients who were otherwise untreatable by conventional techniques.
743
744
BLAND AND OTHERS
XTRACORPOREAL SHOCK-WAVE lithotripsy (from the Greek lithos, which means stone, and tripsy, which means to crush) (ESWL", Dornier Medizintechnik GmbH, Munich, West Germany) has been used to treat urinary tract stones in more than 200,000 patients throughout the world."12 With the development of systems for generation of shock waves and ultrasounds over the last 40 years, energy can be discharged through a probe in contact with a renal or biliary stone (intracorporeal lithotripsy) or delivered to distant foci (extracorporeal lithotripsy). Before treatment with the Dornier HM-3 lithotripter, the patient is placed in a semisitting posture and lowered into a degassed water bath to provide a milieu with impedance similar to that ofsoft body tissues (Fig. 1). The electrode that initiates the electrohydraulic energy is positioned beneath the patient in a semiellipsoid reflector at the first focus (F,). The second focus (F2) is the point of maximum shock-wave impact and is the position at which calculi are aligned. Pressures of 500 to 2000 atm are generated at F2. In vitro and in vivo studies by Brendel et al.3'4 and Newman et al.5'6 confirmed that human gallstones implanted in the gallbladders of dogs could also be fractured when calculi are positioned at F2 using the Dornier HM-3 machine or modifications thereof. Sauerbruch and associates7 and Sackmann et al.8 have treated humans with cholelithiasis and choledocholithiasis using a modified Dornier HM-3 lithotripter (GM-2) in which patients lie in the prone position, thus allowing precise focusing of energy vectors at F2. These studies confirmed a high frequency of stone fragmentation and the ability to clear the gallbladder or choledochus ofcalculi with minimal incidences of morbidity and no deaths. The purpose ofthis prospective study was to determine the efficacy and clinical usefulness of ESWL in the treatment of bile duct stones using the Dornier HM-3 and HM-4 lithotripters. The authors were particularly interested in the ability of the lithotripter to induce bile duct calculi fragmentation, clearance of stones from the biliary tree, and in the assessment of rates of morbidity and mortality sustained in this population that was otherwise untreatable by nonsurgical measures.
E
Materials and Methods A multi-institutional trial was organized by Dornier Medizintechnik GmbH, Munich, West Germany, to conduct a historically controlled prospective trial to determine the clinical usefulness and efficacy of ESWL for bile duct calculi (BDC) with the Dornier HM-3 and HM-4 lithotripters. The study included BDC of the entire biliary tree and the intrahepatic ducts, excluding the cystic duct. Patients with residual stones in the cystic stump were considered eligible. Patients with gallbladder stones alone were excluded from treatment; those with gallstones and BDC
Ann. Surg. * June 1989
were considered to be candidates for treatment of only the BDC. Following FDA application, 11 institutions were designated investigational device exemption (IDE) sites. Thereafter, the investigators submitted applications to their respective institutional review boards (IRB) for the clinical protocol; following review and approval by the IRB and the study monitor (FGM), the study was initiated. Each patient was to serve as their own control. The multiinstitutional trial was performed simultaneously at all IDE sites following patient entry into the study with acquisition of informed consent. Criterion for successful treatment was a stone-free bile duct at discharge or within 30 days for patients entering the study with indwelling biliary tubes. The procedure was considered unsuccessful when it was not possible to fragment or extract stones following two ESWL treatments. Determinations of adverse events (complications) and success of fragmentation of bile duct calculi were made before the patient was discharged. A stone-free discharged patient was the goal of the study. The study was initiated in September, 1987, following a meeting with the monitor and investigators after FDA approval of study design and IRB approval. Data collection and statistical analyses were completed by Biometric Research Institute, Inc., Arlington, Virginia, and managerial regulatory affairs were monitored by Dornier Medizintechnik, GmbH.
Study Design and Methodology ESWL was reserved for stones that could not be cleared from the biliary tree 'using conventional, nonsurgical measures (transendoscopic, transpapillary or per T-tube techniques following sphincterotomy). Endoscopic papillotomy was used as indicated for access to the biliary tree for the removal of residual, reformed, or retained stones. In addition to failures of clearing the biliary tree following endoscopic sphinterotomy, patients with Ttubes within the common bile duct who had unsuccessful attempts at extraction of retained stones via the T-tube tract were considered candidates. Intrabiliary catheters were to remain in the bile duct during ESWL and for appropriate intervals thereafter. These catheters served as conduits for injection of contrast media into the biliary tree to radiographically visualize the radiolucent stones before ESWL to monitor stone position during ESWL, and to evaluate efficacy of stone fragmentation and passage during and after ESWL. The criteria for inclusion and exclusion are shown in Table 1.
Patient Demographics Patients who did not meet the selection criteria were considered ineligible. At the time ofthis report, 42 patients were entered into the trial; 19 (45.2%) were women and 23 (54.8%) were men. Age range was 25 to 95 years (mean
ESWL OF BILE DUCT CALCULI
Vol. 209 * No. 6
SD, 73.5 ± 13.8). Patient weight (mean ± SD) was 145.8 ± 32.4 lbs (range, 83 lbs to 254 lbs); patient height (mean ± SD) was 66.1 ± 4.8 inches (range 55 inches to 81 inches). Patients who were considered eligible had to obtain a status classification before ESWL ofthe American Society of Anesthesiologists (ASA) I to IV.9 Nine patients (21.4%) were Class I, 14 (33.3%) were Class II, 18 (42.9%) were Class III, and 1 patient (2.4%) was Class IV. ASA Class V patients were ineligible. The ASA status classification for these 42 patients was mean + SD, 2.3 ± 0.8. Two thirds of the patients had undergone previous cholecystectomy. Twenty-seven patients (64.3%) had active biliary colic by medical history. Significant concurrent medical illness was evident in most patients and included cardiac arrhythmias in 11 patients (26.2%), hypertension in 13 (31.0%), other cardiovascular diseases in 13 (31.0%), pancreatitis in 6 (14.3%), hepatic disease and/or icterus in 18 (42.9%), pulmonary disease in 9 (21.4%), gastrointestinal disorders in 10 (23.8%), renal disease in 5 (11.9%) and other metabolic disorders in 17 patients (40.5%). Of this high-risk patient group, 14 patients (33.3%) had an abnormal electrocardiogram and 16 (39%) had an abnormal chest radiogram. Table 2 depicts the distribution ofthe number and size of stones by location before first treatment. Patients had
745 TABLE 1. Selection of Patients
+
Inclusion Criteria Patient's informed consent. Bile duct stones that are not extractable endoscopically or percutaneously based on the experience of the individual investigator are treated. The presumed risk of ESWL must be below that of surgery. Successful test-positioning of the patient and localization of the stone.
Preoperative anesthesia risk assignment (ASA) group I-IV. The focal axis of the shockwave must avoid lung, bodies of vertebra, aneurysms of aorta or renal artery and large bone areas with the exception of ribs. Absence of disturbance of coagulation. Exclusion Criteria Informed consent not obtained. All inclusion criteria not fulfilled. Pregnancy; all premenopausal female patients have laboratory tests to exclude pregnancy. Failure to localize stone. Disturbance of coagulation. Presence of pacemaker and arrythmia. Vascular aneurysms or large bone areas in the path of the shockwaves. Upper abdominal surgery within 6 weeks prior to ESWL.
a range of one to eight stones (mean ± SD, 2.7 + 1.9). The common duct represented the most common site for stones, which were seen in 33 patients (78.6%); 10 patients
TABLE 2. Distribution of Number and Size of Stones by Location Prior to First Treatment
Location Papillary Stone Characteristics
Common Duct
No.
(%)
2 2 0 0
(50.0) 9 (50.0) 12
Retained Cystic Duct
(%)
No.
7 5
(27.3) (36.4) (21.2) (15.2)
4
(100.0) 33
4
Common Hepatic Duct
(%)
No.
(%)
1 0 0 0
(100.0)
6 3
(100.0)
(9.5) 33
0
6
4 0 0
(100.0) 17 9
No.
Right Lobar
Left Lobar
(%)
No.
(%)
(100.0)
2 2 0 0
(50.0) (50.0)
0
(60.0) 3 (30.0) 0 (10.0) 0 0
1
(100.0) 10
(100.0) 3
(100.0)
4
(78.6)
1
(2.4) 10
(23.8) 3
(7.1)
(18.2) (51.5) (27.3)
0 1 0 0
5
(50.0) 3 (10.0) 0 (40.0) 0
No.
Intrahepatic
Total Patients
No. (%) No.
(%)
Number of stones 1 2 3 4 or more Total no. of pts. with stones in these locations Location as percentage of total pts. treated
Diameter of largest stone (mm) 1-10 11-20 21-30 31 ormore
Not reported Total no. pts. with stones in these locations Mean Range Standard deviation
0
0 1
(3.0)
0
1
(100.0)
1
4 0 0
0 0
(33.3) (26.2)
0 0 0 0
14
(100.0)
0
4
(9.5)
0
(100.0) 2
(50.0) (25.0) (25.0)
0 0 0 0 0
42 (100.0) Mean ± SD 2.7 ± 1.9 Range 1-8 Diameter of Largest Stone Per Patient 7 (16.7) 22 (52.4) 12 (28.6) 0
1 1 0
0
4 (100.0) 33 (100.0) 1 (100.0) 10 (100.0) 3 (100.0) 4 (100.0) 14.5 16.3 8.3 15 18.4 18.2 4-30 6-10 15-15 5-30 13-20 8-30 12.0 9.4 6.2 2.1 3.5
0
11 5 12
1
(11.9) (28.6)
(2.4)
42 (100.0) 18.5 6-30 6.4
BLAND AND OTHERS
746
Ann. Surg. * June 1989
of nasobiliary drains, balloon extractions, and endoscopicbasket-balloon manipulations. For 42 patients, 1 or 2 ESWL treatments were necessary to clear the biliary tree of BDC. A total of 57 ESWL treatments were conducted with radiographic guidance using contrast media directed via intrabiliary catheters placed transendoscopically at ERCP (54.4%), percutaneous transhepatic methods (10.5%), T-tubes (17.5%), or a combination of these interventional techniques (17.5%).
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FIG. 1. A cross-sectional view of the Dornier HM-3 lithotripter bathtub with positioning of the biliary tract to focus at F2 for treatment. Most patients are positioned such that shock-waves enter the abdomen posteriorly with the stones monitored in real-time by radiographic contrast media. Under appropriate anesthesia or analgesia, shock-wave discharges, triggered by an electrocardiogram, can be delivered to bile duct calculi with the shock-wave focused at F2.
(23.8%) had stones in the next most frequent site, the hepatic duct; 7 patients (16.6%) had stones in lobar ducts; 4 patients (9.5%) had papillary stones; and 1 patient (2.4%) had a retained cystic duct stone. No intrahepatic stones have been accessioned into the study. The majority of patients (n= 22, 52.4%) had stone diameters of 11 mm to 20 mm, whereas 12 patients (28.6%) had BDC diameters of 21 mm to 30 mm. The remainder had pre-ESWL stone size < 10 mm. Stone size ranged from 6 mm to 30 mm (mean ± SD, 18.5 ± 6.4). In pre-ESWL evaluation, intrabiliary catheter cholangiography or sonography indicated that gallbladder stones were present in 13 patients (31%). Impacted stones and/or stenosis of the bile ducts were evident in six (14.3%) and five (11.9%) subjects, respectively. common
Procedures Performed Prior to ESWL Prior to initiating ESWL, these 42 patients had a total of 96 invasive nonsurgical procedures (mean 2.3 per patient). These include endoscopic transpapillary sphincterotomy in 32 patients (76.2%), nasobiliary catheter placement in 36 patients (85.7%), and direct lavage of biliary catheter or percutaneous transhepatic catheter placement in 7 patients each (16.7%). In addition, six patients (14.3%) had intracorporeal lithotripsy using mechanical or percutaneous devices. Techniques used in attempted BDC extraction before referral to the investigators included surgery with common duct exploration, lavage
Antibiotic Coverage Prior to initiating ESWL, all patients received prophylactic broad-spectrum antibiotics that were continued until the biliary system was cleared ofdebris and/or the patient was nonseptic. Two thirds of the patients received 3 or less days of antibiotics; 4 patients (9.5%) received 12 or more days of broad-spectrum coverage. Antibiotic choices were cephalosporins in 21 patients (50%), aminoglycosides in 16 patients (38.1%), or penicillin derivatives in 15 patients (35.7%). ESWL Techniques for Therapy Patients were treated with the Dornier HM-3 or HM4 lithotripter as specified by FDA approval and as previously described.7'8 High-energy shock waves (pressure amplitudes of approximately 1000 BAR and a pulse duration of near 1 microsecond) were generated extracorporeally by a high-current discharge and were focused by a semiellipsoidal reflector. Using contrast media directed into the intrabiliary system, shock waves were radiographically focused to impact on the BDC. In the majority of ESWL treatments, patients were positioned such that the shock waves entered the patient's abdomen posteriorly with the stones focused at F2 (Fig. 1). The positioning procedure, as well as stone fragmentation, was monitored in real-time under fluoroscopic control. Under appropriate anesthesia or analgesia, up to 2400 shock-wave discharges, triggered by an electrocardiogram, were delivered to the BDC when the shock wave focused at F2 during respiratory excursions of the diaphragm. Difficulty with positioning was experienced in 15 treatments (26.3%). Neither patient height nor weight appeared to correlate with difficulty of positioning at simulation or real-time treatment. Within 20 to 125 minutes (mean ± SD, 52.9 ± 20.8 min.) 600 to 2400 shock discharges (mean ± SD, 1924 ± 289) were delivered at 12 kV to 22 kV (mean ± SD, 18.5 ± 1.9). Shock discharge was terminated when stone disintegration was evident following sequential injection of contrast media into the biliary tree or when a predetermined shock-wave limit had been attained. When stone fragments remained in the biliary duct four days after ESWL and were too large to be extracted endoscopically, a second treatment was administered. In-
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ESWL OF BILE DUCT CALCULI
frequently, patients were discharged and readmitted ifthey were asymptomatic with fractured stones or biliary debris. One third of the patients received 3000 or more total shock-wave discharges or a total energy equivalent (kV X number of shocks) of 50,000 or more. Total energy expended ranged from 22 X 103 - 97 X 103 (mean ± SD, 51.4 X 103 ± 21.9 X 103). This limit of shock discharge at the first and second treatments was chosen on the basis for the dose-dependent shock-wave induced damage in experimental animals as determined by Brendel and Enders3 and Delius et al.'0 Greatest total energy was expended in the common duct and common hepatic duct where the greatest stone burden was evident and in patients who had the largest stone diameters (21 mm to 30 mm) at pretreatment. Varying anesthetic techniques were used in this multiinstitutional study, depending on patient cooperation, medical status, and preference of the anesthesiologist. For more than one third of 57 treatments, patients preferred epidural anesthesia (22 treatments or 38.6%). Sedation was used in 22 treatments (38.6%) for those patients preferring regional blocks (2 subjects, 3.5%) or local anesthesia alone (16 subjects, 28.1%). Eighteen patients (31.6%) had general anesthesia. Duration ofanesthesia in these 42 patients ranged from 30 to 230 minutes (mean + SD, 96.4 ± 45.9). Respiratory motions of the diaphragm that initiated liver movement were closely monitored by the anesthesiologist. Patient cooperation was essential to control respiratory movements for patients under epidural, regional, or local blockade. Data Management and Statistical Analysis Chest radiography, cholangiography, abdominal computed tomography, sonography, and laboratory tests (daily liver profiles, amylase, hemoglobin, and WBC) were obtained on admission, at appropriate intervals after ESWL, and prior to discharge. If fragments of BDC did not pass spontaneously after ESWL, invasive extraction techniques were used as deemed necessary by the investigators. When advisable, a second ESWL was performed following recovery during the hospital stay or at subsequent admission. Surgery was to be performed in cases ofunsuccessful ESWL when additional adjunctive measures failed and in the event that complications could not be managed with conventional, nonsurgical techniques. Patient profiles, pre- and post-ESWL treatment techniques, and results were recorded by the institutional investigators in compliance with FDA guidelines and regulations. Entries on patient record forms were made according to the instruction manual for data collection developed by the Biometric Research Institute, Inc. The sponsor and the monitor continuously evaluated the investigation in order to assure compliance with the study design and to evaluate unanticipated adverse events throughout the clinical trial.
747
Data collection and statistical analysis were completed and results were expressed as mean ± SD or as ranges and medians. Where appropriate, the Wilcoxon-ranked sum test, chi-square, Student's t-test or analysis of variance (ANOVA) were applied. Actuarial analysis was performed by the method of Kaplan and Meier." Results with p values < 0.05 were considered significant. Results Treatment was aborted in one patient (1.8%) secondary to the anesthesia-related complication of a regional block with sedation in which the patient had profound respiratory depression. In addition, ESWL treatments were interrupted and then resumed in 4 patients (7%), of which 2 (3.5%) were anesthesia-related; 1 (1.8%) required patient repositioning under general anesthesia; and 1 patient (1.8%) had sonography performed to verify success of the treatment, which was subsequently resumed. No treatments were aborted or interrupted on the basis of medical reasons or lithotripter malfunction. A second ESWL treatment was necessary in 15 patients (35.7%). The predominant reason for retreatment in 14 patients (93.3%) was inadequate fragmentation of BDC, possibly secondary to stone movement during treatment or suboptimal localization of the BDC at F2. Alternatively, the physical properties of the BDC may have precluded fragmentation. For these patients, the investigators considered calculus fragmentation to be incomplete and/or too large to allow transpapillary passage. Further, the investigators considered transendoscopic or percutaneous extraction techniques to have a high probability of failure. An anesthesia-related adverse event necessitated retreatment in one patient (2.4%). Figure 2 denotes the percentage of patients treated with one or two treatments as a function of number of stones before ESWL. No correlation was evident for an increasing stone number to require two ESWL treatments. However, if one evaluates the effectiveness results at final discharge for the percentage of patients who were stone free according to pretreatment number of stones, one sees that stone-free status does correlate with number of stones observed before treatment (Table 3). Using the MantelHaenszel chi-square test, the number of stones before treatment was statistically significant (p = 0.04) in terms of predicting the probability of a stone-free status at discharge. For patients with only one stone before ESWL, 13 (92.9%) were stone free at discharge, and for one patient (7.1%) fragmentation was indeterminate. In addition, as stone number increased to more than 2, the probability of being stone free at discharge was inversely proportional to increasing stone number but was not statistically significant due to the small sample size of the treatment subgroups. As stone numbers increased, the probability
748
Ann. Surg. * June 1989
BLAND AND OTHERS DORNIER U.S. BILE DUCT STUDY
NUMBER OF TREATMENTS BY NUMBER C)F STONES AT PRETREATMEN T 42 PATIENTS PERCFNT 100 80 _ 60 _
55
-445 40 _ 25
20 _
Stone Size as a Determinant of Effectiveness of ESWL
Treatment results 24 hours after ESWL were evaluated by intrabiliary catheters using contrast media for cholangiography, by sonography, or both. Of 57 ESWL treatments in 42 patients, fragmentation of BDC occurred in 47 treatments (90.4%) of 35 patients (94.6%) (Table 5). Stone fragmentation did not occur in five treatments (8.7%). For five patients (1 1.9%), radiographic contrast or sonographic studies were indeterminate for stone fragmentation and/or passage from the biliary tree. Fragments were
retained in 37 (64.9%) of the ESWL treatments for
25 patients (59.5%). Table
o0
4
3
2
l
or
More
NUMBER OF STONES _ ONE TREATMENT
m TWO TREATME.NTS
FIG. 2. Graphic depiction of percentage of patients treate, two ESWL treatments as a function of the number of st onesd No correlation is evident for an increasing stone number to necesssitate a second ESWL treatment.
of stone fragmentation increased proportiona lly, but the patients were not discharged stone free (p = P 5S). For 14 patients with one stone, 6 (42.9%) required 2 ESWL treatments. A mean + SD, 1.4 ± 0.5 treatments per patient for 1 to 8 stones (mean + SD, 2.7 + 1.8) was necessary. As stone numbers increased fromi 2, 3, and more than 4, the relative percentage of patientLs requiring a second treatment was 45.4%, 20%, and 25%, r(espectively. In this relatively small series, increase in stonte numbers did not correlate with the necessity for a secondItreatment. In contrast, as stone burden increased, as dete rmined by the sum of the diameter (mm) of the largest stones, the probability of a second treatment increased. If the sum ofdiameter of the largest stones exceeded 21 mrm, a second ESWL treatment was necessary in over one half of the patients (Table 4).
ameter
5
documents the largest di-
of retained fragment size (millimeters) for 25
pa-
tients with retained biliary debris. For retained fragments of 3 mm or less, 4 mm to 6 mm, 7 mm to 9 mm, or 10 mm or more, the number of patients and frequency of this observation was 3 (12%), 3 (12%), 1 (4%), and 17 (68%), respectively. For one patient (4%) determination of the largest fragment size was not possible by any imaging technique. Four patients cleared the biliary tree of residual fragments/debris without further therapeutic intervention. Before discharge, adjunctive, nonsurgical procedures were necessary for stone removal in 21 patients (50%). These procedures are depicted in Table 6 and include transpapillary or percutaneous endoscopic extraction in 10 patients (47.6%), biliary lavage in 8 (38.1%), endoscopic placement of bile duct prosthesis in 1 (4.8%), or combinations in 4 patients (19%). Of the auxillary measures required to clear the biliary tree in one half of subjects, no statistically significant differences (p = 0.926) were apparent for patients with retained fragments measuring 10 mm or more vs. fragments of 9 mm or less. Operation was performed after ESWL and before discharge in one patient and at a subsequent date in a second (total 9.5%). Based on the false-positive sonographic data of residual fragments in one patient, the common duct was explored
TABLE 3. U.S. Bile Duct Lithotripsy Study: Effectiveness Results. Distribution of Final Discharge Results According to Pretreatment Number of Stones Results at Discharge Not Stone-Free*
Fragmentation
Stone Free*
Fragmented
Number of Stones Pretreatment
No.
(%)
No.
1 2 3 4 or more
13 8 3 7
0 2
Subtotal
31
(92.9) (72.7) (60.0) (58.3) (73.8)
*p
=
1 5
8
(%)
(18.1) (20.0) (41.7) (19.0)
Not Fragmented No.
(%)
0 0 1 0
(20.0)
1
(2.4)
0.04 Mantel-Haenszel test comparing no. of stones pretreatment to results at discharge.
Unknown
No.
(%)
1 1
(7.1) (9.1)
0 0 2
(4.8)
Total 14 11 5 12
(100.0) (100.0) (100.0)
42
(100.0)
(100.0)
Vol. 209 NO. 6
ESWL OF BILE DUCIT CALCULI
TABLE 4. Distribution of Sum of Diameters of Largest Stones in Each Location by Number of Treatments
749
TABLE 6. U.S. Bile Duct Lithotripsy Study: Treatment Results at Discharge for Patients
Number of Treatments
Sum of Diameter of One Largest Stones (mm) No. (%) 1-10 11-20 21-30 31-40 41-50 51 ormore
4 14 6
Subtotal Not reported Total no.
26 1
patients
27
Three or More
Two No.
(%)
(46.7) (33.3) (13.3) (6.7)
(7.7)
0 7 5 2 1 0
(100.0)
15
(15.4) (53.8) (23.1)
0 0 2
Total
No. (%) No.
0 0 0 0 0 0
4 21
41
0
0 0
15
0
42*
(100)
11
2 1 2
(%)
(9.8) (51.2) (26.8) (4.9) (2.4) (4.9)
(100)
1
Treatment per patient: Mean ± SD, 1.4 + 0.5; Range, 1-2. Stones per patient: Mean ± SD, 2.7 ± 1.8; Range, 1-8. * 42 patients had 57 treatments.
without findings of stone or debris. A choledochoduodenostomy was performed in both patients following duct exploration. Time of hospitalization from pre-ESWL evaluation or catheter placement to discharge ranged from one to 31 days (mean 9.6). At the time of discharge of these 42 patients, 31 (73.8%) were stone free, whereas 8 (19%) had retained calculi that were fragmented and 1 (2.4%) had retained stones that were unfragmented. Documentation of stone passage or fragmentation could not be determined in two patients (4.8%) despite high-quality imaging with cholangiography and/or sonography. TABLE 5. U.S. Bile Duct Lithotripsy Study: Treatment Results 24 Hours Post-ESWL
ESWL Treatments No.
(%)
No.
(%)
Total Fragmentation Indeterminate Fragments retained Diameter: Largest fragments retained
