Dig Dis Sci DOI 10.1007/s10620-013-2914-4
ORIGINAL ARTICLE
Dilation-Assisted Stone Extraction: An Alternative Method for Removal of Common Bile Duct Stones Guodong Li • Qiuping Pang • Xiujuan Zhang Haiyan Dong • Rong Guo • Hailan Zhai • Yanchun Dong • Xinyong Jia
•
Received: 9 April 2013 / Accepted: 5 October 2013 Ó Springer Science+Business Media New York 2013
Abstract Background Dilation-assisted stone extraction, also termed small endoscopic sphincterotomy (EST) plus endoscopic papillary balloon dilatation, is more efficient than EST alone for removal of large common bile duct (CBD) stones. However, whether this technique can be used for all stones is unclear. Aim This study was designed to evaluate the efficacy and complications of dilation-assisted stone extraction for CBD stones. Methods A total of 462 patients with CBD stones were randomized to undergo either dilation-assisted stone extraction (group A) or EST (group B). The efficacy and complications of the two techniques were compared.
G. Li Q. Pang X. Zhang H. Dong R. Guo H. Zhai Y. Dong X. Jia (&) Department of Endoscopy, Shandong Provincial Qianfoshan Hospital, 16766 Jingshi Road, Jinan 250014, Shandong, China e-mail: [email protected] G. Li e-mail: [email protected] Q. Pang e-mail: [email protected] X. Zhang e-mail: [email protected] H. Dong e-mail: [email protected] R. Guo e-mail: [email protected] H. Zhai e-mail: [email protected] Y. Dong e-mail: [email protected]
Results Groups A and B showed similar outcomes in terms of stone removal. The short-term and 1-year complication rates were also similar between the two groups. However, the first-session stone removal rate in group A was significantly higher than that in group B. Mechanical lithotripsy was required significantly more often in group B than in group A. The total procedure time and total fluoroscopy time in group A were significantly shorter than those in group B. Conclusions Dilation-assisted stone extraction and EST are safe and effective techniques for the treatment of CBD stones. Dilation-assisted stone extraction has high efficiency. This technique is an alternative method for removal of CBD stones. Keywords Endoscopic sphincterotomy Choledocholithiasis Endoscopic retrograde cholangiopancreatography Lithotripsy
Introduction Endoscopic sphincterotomy (EST) is widely used to remove common bile duct (CBD) stones [1, 2]. Although EST is an attractive method for removal of CBD stones, it is still associated with complications, including acute pancreatitis, hemorrhage, perforation, and cholangitis [3, 4]. In 2003, Ersoz et al. [5] introduced small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation (sEST ? EPBD) for the removal of large bile duct stones (C15 mm) that are difficult to remove by EPBD or EST alone [6–8]. This technique was considered to be useful in patients with distal CBD narrowing and in those in whom the papillary orifice was smaller than the size of
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Fig. 1 Enrollment, randomization, and follow-up. One patient who was randomly assigned to the EST group had to undergo a small EST ? EPBD because of peri ampullary diverticula. This patient was
included in the EST group in the modified intention-to-treat analysis but not in the per-protocol analysis
the biliary stones after EST. For very small stones, the terminal bile duct configuration may account for the difficulty of stone removal. When balloon dilation is used, both the papillary sphincter and the distal bile ducts are dilated, allowing for easy removal of the stone with a retrieval balloon. It seems that sEST ? EPBD is more efficient than EST. The present study was designed to test this theory. The aims of this prospective study were to evaluate the efficiency and safety of sEST ? EPBD versus EST alone in the treatment of CBD stones and determine whether the indications for sEST ? EPBD can be expanded.
Patients and Methods
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Patients were enrolled from 1 May 2008 to 30 April 2011. The institutional review board of the hospital approved the study protocol, and written informed consent was obtained from each patient. Patients This prospective randomized trial was conducted at a large teaching hospital (Fig. 1). Inclusion criteria were: (1) age
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of C18 years and (2) the presence of bile duct stones. Exclusion criteria were: (1) active acute pancreatitis, (2) septic shock, (3) presence of intrahepatic stones, (4) malignant pancreatic, biliary, or ampullary disorders, (5) prior sphincterotomy, (6) coagulopathy (international normalized ratio of [1.2, partial thromboplastin time greater than twice that of control), (7) platelet count of \50,000 9 103/lL, (8) sphincter of Oddi dysfunction, (9) primary sclerosing cholangitis, (10) Caroli disease, (11) pregnancy, (12) history of Billroth II or Roux-en-Y reconstruction, (13) stone diameter of [30 mm, and (14) inability to give informed consent. Randomization was performed by an independent statistician using a random number generator. The assignments were written on cards, sealed in identical opaque envelopes, and delivered to the hospital. Each assignment was concealed until the time of the interim analysis. The investigators opened the envelopes and assigned the subjects to the designated treatment groups after confirmation that the patient met both inclusion criteria and met no exclusion criteria. The patient and the research assistant conducting the follow-up interviews were blinded to the assignment. Data Collection Baseline data were collected from the patients before endoscopic retrograde cholangiopancreatography (ERCP), and routine laboratory values were obtained in the last 24 h. After initial diagnostic ERCP, the diameter of the CBD, number of stones, size of the largest stone, procedure time, fluoroscopy time, and use of mechanical lithotripsy (ML) were recorded. Twenty-four hours later, the patients were examined, and the presence of acute pancreatitis, bleeding, acute cholangitis, perforation, or any other complications was recorded. All patients with acute pancreatitis completed the 30-day follow-up necessary to determine the severity of acute pancreatitis. Follow-up data were collected by telephone interview conducted by a research assistant. Patients were considered to be lost to follow-up if they could not be contacted or declined to participate in the telephone interview within 6 months of randomization. Primary end points were the overall stone removal rate, complications, and stone removal rate in the first session. The secondary end points were the procedure time, fluoroscopy time, use of ML, and number of attempts needed to clear the stones. Endoscopic Procedures ERCP was performed with a side-viewing video duodenoscope (TJF-150 or TJF-160; Olympus Optical Co.,
Tokyo, Japan). Prophylactic antibiotics were routinely given. Endoscopic procedures were performed under conscious sedation. After selective cannulation of the CBD, an initial cholangiogram was taken. In the EST group, EST was completed to the full length of the transverse fold, and the sphincterotomy incision was not extended beyond the top of the transverse fold. In the sEST ? EPBD group, the length of the sphincterotomy incision was limited to one-third of the transverse fold. After small EST, a balloon catheter was passed over the guidewire and positioned across the main duodenal papilla. The size of the balloon was matched to the diameters of the bile duct and stones (Fig. 2). The balloon was then gradually filled with diluted contrast medium under endoscopic and fluoroscopic guidance to observe the gradual disappearance of the waist in the balloon, which was taken to indicate progressive dilation of the orifice. Once the waist disappeared, the balloon remained inflated for 60 s. We also used the AllianceTM inflation system (Boston Scientific Microvasive, Cork, Ireland) to monitor balloon pressure. A mechanical lithotripter was introduced to prevent stone impaction and then to fragment the stones when standard methods failed to remove them. When the retrieval basket seized up, an emergency lithotripter was prepared. After lithotripsy, endoscopic biliary drainage was performed in all patients using nasobiliary drainage tubes. Definitions If the CBD stones could not be completely cleared within 1 h, the procedure was considered to be unsuccessful. A second ERCP procedure was performed for retrieval of residual bile duct stones. Complete stone removal was confirmed by balloon-occluded cholangiography. If the stones could not be cleared after two attempts, the patients were recommended to undergo surgery. Post-ERCP complications were standardized in a consensus conference [9] held in 1991. Briefly, post-ERCP pancreatitis (PEP) was defined by consensus criteria: clinical evidence of pancreatitis; elevation of pancreatic enzymes to three times the upper limit of normal 24 h after the procedure; and hospital admission for 2–3 days (mild pancreatitis), 4–9 days (moderate pancreatitis), or longer than 10 days (severe pancreatitis). Hemorrhage was considered to be clinically significant only if there was clinical evidence of bleeding, such as melena or hematemesis, with an associated decrease in the hemoglobin concentration of at least 2 g/dL or the need for a blood transfusion. Cholangitis was considered to be characterized by right upper quadrant abdominal tenderness, a temperature of [38 °C, and elevated liver enzyme levels. The procedure time was
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Fig. 2 Small EST ? EPLBD technique. a Cholangiogram showed large and multiple bile duct stones. b Small EST was performed. c Papillary dilation with CRE balloon(15–16.5–18 mm). d X-ray
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shows large balloon expanded. e Large biliary orifice can be seen. f Large bile duct stone removal without mechanical lithotripsy (ML)
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defined as the total time between insertion and withdrawal of the endoscope. The fluoroscopy time was automatically calculated by the fluoroscopy unit in the ERCP room. Statistical Analysis The modified intention-to-treat analysis (full analysis set) included all patients excluding those in whom an unsuccessful cannulation occurred (whose data were censored at that time). Patients with protocol violations were considered in the modified intention-to-treat analysis to have had treatment failure. For the per-protocol analysis, only patients who received treatment according to the protocol were included. Data are presented as the mean ± SD or median with range. Categorical variables were compared with the use of the chi-square test. Continuous variables were compared with the use of the t test. All reported P values were twotailed, and P values of \0.05 were considered to indicate statistical significance. The analysis was conducted using SPSS statistical software, version 17.0 (SPSS Institute, Cary, NC, USA).
Table 1 Baseline characteristics of the patients Characteristics
sEST ? EPBD (n = 232)
EST (n = 230)
P value
Sex (M/F)
96/136
87/143
0.435
61.8 ± 16.7
60.6 ± 16.6
0.421
Age (years) Mean ± SD Clinical presentation 88 (37.9 %)
92 (40 %)
0.648
Periampullary diverticulum
Acute cholangitis
93 (40 %)
102 (44.3 %)
0.354
Gallstone
70 (30.2 %)
81 (35.2 %)
0.248
Post-cholecystectomy
74 (31.9 %)
82 (35.7)
0.393
Billroth I reconstruction
5 (2.2 %)
4 (1.7 %)
0.505
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, M male, F female, SD standard deviation
Table 2 Baseline cholangiographic characteristics of the patients Characteristics
sEST ? EPBD
EST
P value
13.2 ± 3.7
12.7 ± 3.5
0.143
Debris
23 (10.1 %)
25 (11 %)
0.748
B2
136 (59.6 %)
144 (63.4 %)
0.406
C3
69 (30.3 %)
58 (25.6 %)
0.263
Largest bile duct diameter (mm) Mean ± SD Number of stones
Results Patients and Enrollment From 1 May 2008 to 30 April 2011, a total of 478 patients were enrolled in the study; 16 patients were excluded before randomization (Fig. 1). Patient characteristics are summarized in Table 1. The baseline characteristics were well balanced. A total of 232 patients (male:female ratio, 96:136; mean age, 61.8 years) were randomized to the sEST ? EPBD group, and 230 (male:female ratio, 87:143; mean age, 60.6 years) were randomized to the EST group. There were no differences between the sEST ? EPBD and EST groups with regard to acute cholangitis (37.9 vs. 40 %, respectively; P = 0.648), periampullary diverticulum (40 vs. 44.3 %, respectively; P = 0.354), gallstones (30.2 vs. 35.2 %, respectively; P = 0.248), postcholecystectomy (31.9 vs. 35.7 %, respectively; P = 0.393), and Billroth-I reconstruction (2.2 vs. 1.7 %, respectively; P = 0.505). The statistical analysis was repeated by per-protocol analysis. There were no differences in the baseline characteristics, success rate, or complication rate between the two groups. Clinical Outcomes There was no statistically significant difference in the cannulation success rate between the two groups. Precut
Largest size of stones (mm) \12
138 (60.5 %)
141 (62.1 %)
0.728
C12
90 (39.5 %)
86 (37.9 %)
0.728
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
sphincterotomy and the double-guidewire technique were performed in cases of difficult cannulation. According to the initial diagnostic cholangiogram, the CBD was dilated in all patients. There were no statistically significant differences in the stone size, stone number, or CBD diameter between the two groups (Table 2). There was no statistically significant difference in the final clearance of CBD stones between the sEST ? EPBD and EST groups (97.4 vs. 94.7 %, respectively; P = 0.146) (Table 3). When the stone was \12 mm, success rate was similar between groups (97.1 vs. 99.3 %, respectively; P = 0.354). When the stone was ‡12 mm, success rate differed between the two groups (97.8 vs. 87.3 %, respectively; P = 0.021). However, in the first session, the stone clearance rate was significantly higher in the sEST ? EPBD group than in the EST group (87.7 vs. 71.4 %; P \ 0.05). ML was more frequently performed in the EST group than in the sEST ? EPBD group (35.2 vs. 12.3 %, respectively; P \ 0.05).
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sEST ? EPBD
Table 4 Complications within 24 h in the two groups EST
P value
Complications
sEST ? EPBD
EST
P value 0.544
Complete removal of stone
222 (97.4 %)
215 (94.7 %)
0.146
Acute pancreatitis
12 (5.3 %)
15 (6.6 %)
Success rate with stone C 12 mm
88 (97.8 %)
75 (87.3 %)
0.021
Mild
7 (3.1 %)
10 (4.4 %)
Success rate with stone \ 12 mm
134 (97.1 %)
140 (99.3 %)
0.354
Moderate
5 (2.2 %)
5 (2.2 %)
Success rate in the first session
200 (87.7 %)
162 (71.4 %) \0.05
Severe
0
0
Rate of ML
28 (12.3 %)
80 (35.2 %)
Hemorrhage
4 (1.8 %)
12 (5.3 %)
0.041
Perforation
0
0
-
Total
16 (7.0 %)
27 (11.9 %)
0.075
\0.05
Procedure time (min) Mean ± SD
38.6 ± 15.5
47.1 ± 20.2
\0.05
Radiation exposure time (min) Mean ± SD
17.3 ± 7.0
26.5 ± 10.8
\0.05
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
The total procedure time and fluoroscopy time included the cannulation session and stone removal session. The procedure time and fluoroscopy time differed significantly between the two groups (38.6 ± 15.5 vs. 47.1 ± 20.2 min, P \ 0.05 and 17.3 ± 7.0 vs. 26.5 ± 10.8 min, P \ 0.05, respectively).
Complications and Adverse Events The overall complication rates (Table 4) were not significantly different between the sEST ? EPBD and EST groups (7.0 vs. 11.9 %, respectively; P = 0.075). The rates of pancreatitis were not significantly different between the two groups (5.3 vs. 6.6 %, respectively; P = 0.544), and all cases were either mild or moderate. In terms of hemorrhage, bleeding occurred in 4 patients (1.8 %) in the sEST ? EPBD group and 12 patients (5.3 %) in the EST group with a statistically significant difference (P = 0.041). No patient required surgical intervention or died as a result of the ERCP-induced bleeding. All bleeding was managed conservatively using saline-epinephrine injections, a retrieval balloon, or dilating balloon compression. No death and perforation complications were observed in either group. One-year complications (Table 5) included right upper quadrant abdominal pain, bile duct stone recurrence, cholangitis, acute cholecystitis, bile duct malignancy, and pancreatitis. Complications occurred in 18 patients in the sEST ? EPBD group and in 23 patients in the EST group. Fourteen patients in the sEST ? EPBD group and 16 patients in the EST group had right upper quadrant abdominal pain without fever. Biliary and/or pancreaticrelated problems occurred in four and seven patients in the sEST ? EPBD and EST groups, respectively. There were no statistically significant differences in these parameters.
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Complication evaluation according to Cotton’s criteria. Hemorrhage include acute endoscopic bleeding and post-procedure bleeding sEST ? EPBD limited endoscopic sphincterotomy plus Endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
Table 5 One-year complications in the two groups Complications
sEST ? EPBD
EST
P value
Abdominal pain
14 (6.14 %)
16 (7.0 %)
0.696
Biliary problems
3 (1.32 %)
5 (2.2 %)
0.503
Acute cholangitis
2 (0.88 %)
2 (0.88 %)
Acute cholecystitis
0
1 (0.44 %)
CBD stone recurrence
1 (0.44 %)
2 (0.88 %)
Acute pancreatitis
1 (0.44 %)
2 (0.88 %)
Biliary malignancy
0
0
Total
18 (7.9 %)
23 (10.1 %)
0.623 0.405
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy
Discussion EST has been widely accepted as a standard method for CBD stone removal [1, 2]. Although the safety of EST has been proven in many studies, this technique carries procedure-related risks (5–11 %) [3, 4] such as acute pancreatitis, hemorrhage, and perforation. Attention has also been given to the potential long-term complications of sphincterotomy, such as an increased incidence of ascending cholangitis and recurrence of bile duct stones. In most cases however, EST still remains the first-choice treatment [10]. Ersoz et al. [5] first reported the use of EST followed by large-diameter (15- to 20-mm) EPBD as an alternative management technique for large bile duct stones. Several studies [11–16] subsequently confirmed that sEST ? EPBD can improve efficiency and reduce complications. Difficulty in clearing bile duct stones is caused by the presence of large stones, multiple stones, barrel-shaped stones, and tapering of the distal CBD. For large CBD stones, sEST ? EPBD is an effective and safe treatment.
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In addition, the procedure can be completed with a shorter procedure time and fluoroscopy time than EST alone. For very small stones, tapering of the distal CBD may account for the difficulty of stone removal. When a dilation balloon is used, both the papillary sphincter and distal bile duct are dilated, allowing for easy removal of the stone with a retrieval balloon. These advantages raise the question of whether the indications for sEST ? EPBD can be expanded. No previous studies have examined this question. In our study, the ultimate success rate was similar between the sEST ? EPBD and EST groups. sEST ? EPBD is an effective treatment for CBD stones. Our data showed that the success rate of sEST ? EPBD for complete clearance of bile duct stones in the first ERCP session was higher than that of EST, although there was no statistically significant difference in the ultimate success rate. When the stone was \ 12 mm, success rate was similar between groups. When the stone was ‡ 12 mm, success rate was significantly higher in the sEST ? EPBD group than in the EST group. The results suggest sEST ? EPBD is effective for CBD stones. Importantly, in the first session, the stone clearance rate was significantly higher in the sEST ? EPBD group than in the EST group. The result suggests sEST ? EPBD can remove the CBD stones with high efficiency. The main causes of incomplete stone extraction in the first session were large stones, multiple stones, or tapering of the distal CBD. Furthermore, the need for ML was significantly lower in the sEST ? EPBD group than in the EST group. For this reason, we considered that the orifice after sEST ? EPBD made it possible to more easily remove bile duct stones compared with EST alone. The use of ML may create many stone fragments that are difficult to clear. Because few patients in the sEST ? EPBD group needed ML and underwent whole stone removal, the total procedure time and fluoroscopy time were significantly shorter than those in the EST group. These results are similar to those in a previous retrospective analysis [12]. Although the indications were expanded, these data are in agreement with previous published results. sEST ? EPBD is not only effective, but also highly efficient. However, will using balloon dilation in all cases, even for small stones, unnecessarily increase the cost to patients? Theoretically, a large orifice after sEST ? EPBD makes it possible to more easily remove CBD stones than with EST alone. The stones can only be removed with a retrieval balloon; the retrieval basket is not necessary. And the need for ML was significantly lower in the sEST ? EPBD group than in the EST group. Importantly, the total procedure time and fluoroscopy time are also short. The method will not increase the cost to patients. Although the procedure-related short-term complications were not significantly different between the two
groups, the complication rate in the sEST ? EPBD group was lower. Although about 40 % of the patients had perivaterian diverticuli, perforations were not encountered in any patients who underwent sEST ? EPBD or EST. Perivaterian diverticuli are a cause of CBD stones and can increase the risk of perforation of full EST. One patient in the EST group could not undergo EST because of the presence of perivaterian diverticuli. Because a nasal biliary drainage catheter was routinely inserted at the end of the procedure, no cholecystitis or cholangitis occurred in either group. Endoscopic biliary drainage is used for prevention of complications such as cholecystitis and cholangitis. We also take a cholangiogram to confirm complete clearance through the nasobiliary drainage tube. Although this may increase the cost to patients, safety of the procedure is more important. In several other reports [12–16], the risk of PEP following sEST ? EPBD was lower than that following EST. The rate of acute pancreatitis was similar between the sEST ? EPBD and EST groups. The reason for this may be related to multiple factors, such as age, pancreatic stent placement, and the wire-guided cannulation technique. Bleeding occurred in four patients (1.8 %) in the sEST ? EPBD group and 12 patients (5.3 %) in the EST group with a statistically significant difference in our study. Freeman et al. [3] and Cotton et al. [9] reported a bleeding rate of 1–3 % in the EST group. The bleeding rates in other recent studies were similar to those of our study. No patients required surgical intervention or died as a result of the ERCP-induced bleeding. All bleeding was managed conservatively. We suspect that the difference in the bleeding rates between the sEST ? EPBD and EST groups may have been the result of balloon compression of the sphincterotomy site. This may be why patients who underwent sEST ? EPBD had a lower incidence of endoscopically observed bleeding. One-year complications [17–21] included right upper quadrant abdominal pain, bile duct stone recurrence, cholangitis, acute cholecystitis, bile duct malignancy, and pancreatitis. There were no statistically significant differences in these parameters. To obtain a much more thorough understanding of long-term complications, the follow-up study is necessary. In conclusion, dilation-assisted stone extraction, with its higher first-session success rate and shorter procedure time and fluoroscopy time, is more efficient than EST. Dilationassisted stone extraction is an alternative method for removal of CBD stones. The balloon-equipped sphincterotome may be used in the future. Acknowledgments We are indebted to Zilong Lu of the Shandong Center for Disease Control and Prevention for his help with the statistical data analysis. Conflict of interest
None.
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References 1. Kawai K, Akasaka Y, Murakami K, et al. Endoscopic sphincterotomy of the ampulla of Vater. Gastrointest Endosc. 1974;20:148–151. 2. Classen M, Demling L. Endoscopic sphinetemtomy of the papilla of vater and extraction of stones from the choledochal duct (German). Dtsch Med Wochenschr. 1974;99:496–497. 3. Freeman LS, Douglas BN, Sherman S, et al. Complications of endoscopic biliary sphincterotomy. N Engl J Med. 1996;335: 909–918. 4. Geenen JE, Toouli J, Hogan WJ, et al. Endoscopic sphincterotomy: follow up evaluation of effects on the sphincter of Oddi. Gastroenterology. 1984;87:754–758. 5. Ersoz G, Tekesin O, Ozutemiz AO, et al. Biliary sphincterotomy plus dilation with a large balloon for bile duct stones that are difficult to extract. Gastrointest Endosc. 2003;57:156–159. 6. Minami A, Nakatsu T, Uchida N, et al. Papillary dilatation vs sphincterotomy in endoscopic removal of bile duct stones. A randomized trial with manometric function. Dig Dis Sci. 1995; 40:2550–2554. 7. Minami Atsushi, Hirose Shinji, Nomoto Tomohiro, et al. Small sphincterotomy combined with papillary dilation with large balloon permits retrieval of large stones without mechanical lithotripsy. World J Gastroenterol. 2007;13(15):2179–2182. 8. Kim HG, Cheon YK, Cho YD, et al. Small sphincterotomy combined with endoscopic papillary large balloon dilation versus sphincterotomy. World J Gastroenterol. 2009;15(34):4298– 4304. 9. Cotton PB, Lehman G, Vennes J, et al. Endoscopic sphinctrotomy complications and their management: an attempt at consensus. Gastrointest Endosc. 1991;37:383–393. 10. Lin CK, Lai KH, Chan HH, et al. Endoscopic balloon dilatation is a safe method in the management of common bile duct stones. Dig Liver Dis. 2004;36:68–72. 11. Vlavianos P, Chopra K, Mandalia S, et al. Endoscopic balloon dilatation versus endoscopic sphincterotomy for the removal of
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ORIGINAL ARTICLE
Dilation-Assisted Stone Extraction: An Alternative Method for Removal of Common Bile Duct Stones Guodong Li • Qiuping Pang • Xiujuan Zhang Haiyan Dong • Rong Guo • Hailan Zhai • Yanchun Dong • Xinyong Jia
•
Received: 9 April 2013 / Accepted: 5 October 2013 Ó Springer Science+Business Media New York 2013
Abstract Background Dilation-assisted stone extraction, also termed small endoscopic sphincterotomy (EST) plus endoscopic papillary balloon dilatation, is more efficient than EST alone for removal of large common bile duct (CBD) stones. However, whether this technique can be used for all stones is unclear. Aim This study was designed to evaluate the efficacy and complications of dilation-assisted stone extraction for CBD stones. Methods A total of 462 patients with CBD stones were randomized to undergo either dilation-assisted stone extraction (group A) or EST (group B). The efficacy and complications of the two techniques were compared.
G. Li Q. Pang X. Zhang H. Dong R. Guo H. Zhai Y. Dong X. Jia (&) Department of Endoscopy, Shandong Provincial Qianfoshan Hospital, 16766 Jingshi Road, Jinan 250014, Shandong, China e-mail: [email protected] G. Li e-mail: [email protected] Q. Pang e-mail: [email protected] X. Zhang e-mail: [email protected] H. Dong e-mail: [email protected] R. Guo e-mail: [email protected] H. Zhai e-mail: [email protected] Y. Dong e-mail: [email protected]
Results Groups A and B showed similar outcomes in terms of stone removal. The short-term and 1-year complication rates were also similar between the two groups. However, the first-session stone removal rate in group A was significantly higher than that in group B. Mechanical lithotripsy was required significantly more often in group B than in group A. The total procedure time and total fluoroscopy time in group A were significantly shorter than those in group B. Conclusions Dilation-assisted stone extraction and EST are safe and effective techniques for the treatment of CBD stones. Dilation-assisted stone extraction has high efficiency. This technique is an alternative method for removal of CBD stones. Keywords Endoscopic sphincterotomy Choledocholithiasis Endoscopic retrograde cholangiopancreatography Lithotripsy
Introduction Endoscopic sphincterotomy (EST) is widely used to remove common bile duct (CBD) stones [1, 2]. Although EST is an attractive method for removal of CBD stones, it is still associated with complications, including acute pancreatitis, hemorrhage, perforation, and cholangitis [3, 4]. In 2003, Ersoz et al. [5] introduced small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation (sEST ? EPBD) for the removal of large bile duct stones (C15 mm) that are difficult to remove by EPBD or EST alone [6–8]. This technique was considered to be useful in patients with distal CBD narrowing and in those in whom the papillary orifice was smaller than the size of
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Fig. 1 Enrollment, randomization, and follow-up. One patient who was randomly assigned to the EST group had to undergo a small EST ? EPBD because of peri ampullary diverticula. This patient was
included in the EST group in the modified intention-to-treat analysis but not in the per-protocol analysis
the biliary stones after EST. For very small stones, the terminal bile duct configuration may account for the difficulty of stone removal. When balloon dilation is used, both the papillary sphincter and the distal bile ducts are dilated, allowing for easy removal of the stone with a retrieval balloon. It seems that sEST ? EPBD is more efficient than EST. The present study was designed to test this theory. The aims of this prospective study were to evaluate the efficiency and safety of sEST ? EPBD versus EST alone in the treatment of CBD stones and determine whether the indications for sEST ? EPBD can be expanded.
Patients and Methods
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Patients were enrolled from 1 May 2008 to 30 April 2011. The institutional review board of the hospital approved the study protocol, and written informed consent was obtained from each patient. Patients This prospective randomized trial was conducted at a large teaching hospital (Fig. 1). Inclusion criteria were: (1) age
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of C18 years and (2) the presence of bile duct stones. Exclusion criteria were: (1) active acute pancreatitis, (2) septic shock, (3) presence of intrahepatic stones, (4) malignant pancreatic, biliary, or ampullary disorders, (5) prior sphincterotomy, (6) coagulopathy (international normalized ratio of [1.2, partial thromboplastin time greater than twice that of control), (7) platelet count of \50,000 9 103/lL, (8) sphincter of Oddi dysfunction, (9) primary sclerosing cholangitis, (10) Caroli disease, (11) pregnancy, (12) history of Billroth II or Roux-en-Y reconstruction, (13) stone diameter of [30 mm, and (14) inability to give informed consent. Randomization was performed by an independent statistician using a random number generator. The assignments were written on cards, sealed in identical opaque envelopes, and delivered to the hospital. Each assignment was concealed until the time of the interim analysis. The investigators opened the envelopes and assigned the subjects to the designated treatment groups after confirmation that the patient met both inclusion criteria and met no exclusion criteria. The patient and the research assistant conducting the follow-up interviews were blinded to the assignment. Data Collection Baseline data were collected from the patients before endoscopic retrograde cholangiopancreatography (ERCP), and routine laboratory values were obtained in the last 24 h. After initial diagnostic ERCP, the diameter of the CBD, number of stones, size of the largest stone, procedure time, fluoroscopy time, and use of mechanical lithotripsy (ML) were recorded. Twenty-four hours later, the patients were examined, and the presence of acute pancreatitis, bleeding, acute cholangitis, perforation, or any other complications was recorded. All patients with acute pancreatitis completed the 30-day follow-up necessary to determine the severity of acute pancreatitis. Follow-up data were collected by telephone interview conducted by a research assistant. Patients were considered to be lost to follow-up if they could not be contacted or declined to participate in the telephone interview within 6 months of randomization. Primary end points were the overall stone removal rate, complications, and stone removal rate in the first session. The secondary end points were the procedure time, fluoroscopy time, use of ML, and number of attempts needed to clear the stones. Endoscopic Procedures ERCP was performed with a side-viewing video duodenoscope (TJF-150 or TJF-160; Olympus Optical Co.,
Tokyo, Japan). Prophylactic antibiotics were routinely given. Endoscopic procedures were performed under conscious sedation. After selective cannulation of the CBD, an initial cholangiogram was taken. In the EST group, EST was completed to the full length of the transverse fold, and the sphincterotomy incision was not extended beyond the top of the transverse fold. In the sEST ? EPBD group, the length of the sphincterotomy incision was limited to one-third of the transverse fold. After small EST, a balloon catheter was passed over the guidewire and positioned across the main duodenal papilla. The size of the balloon was matched to the diameters of the bile duct and stones (Fig. 2). The balloon was then gradually filled with diluted contrast medium under endoscopic and fluoroscopic guidance to observe the gradual disappearance of the waist in the balloon, which was taken to indicate progressive dilation of the orifice. Once the waist disappeared, the balloon remained inflated for 60 s. We also used the AllianceTM inflation system (Boston Scientific Microvasive, Cork, Ireland) to monitor balloon pressure. A mechanical lithotripter was introduced to prevent stone impaction and then to fragment the stones when standard methods failed to remove them. When the retrieval basket seized up, an emergency lithotripter was prepared. After lithotripsy, endoscopic biliary drainage was performed in all patients using nasobiliary drainage tubes. Definitions If the CBD stones could not be completely cleared within 1 h, the procedure was considered to be unsuccessful. A second ERCP procedure was performed for retrieval of residual bile duct stones. Complete stone removal was confirmed by balloon-occluded cholangiography. If the stones could not be cleared after two attempts, the patients were recommended to undergo surgery. Post-ERCP complications were standardized in a consensus conference [9] held in 1991. Briefly, post-ERCP pancreatitis (PEP) was defined by consensus criteria: clinical evidence of pancreatitis; elevation of pancreatic enzymes to three times the upper limit of normal 24 h after the procedure; and hospital admission for 2–3 days (mild pancreatitis), 4–9 days (moderate pancreatitis), or longer than 10 days (severe pancreatitis). Hemorrhage was considered to be clinically significant only if there was clinical evidence of bleeding, such as melena or hematemesis, with an associated decrease in the hemoglobin concentration of at least 2 g/dL or the need for a blood transfusion. Cholangitis was considered to be characterized by right upper quadrant abdominal tenderness, a temperature of [38 °C, and elevated liver enzyme levels. The procedure time was
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Fig. 2 Small EST ? EPLBD technique. a Cholangiogram showed large and multiple bile duct stones. b Small EST was performed. c Papillary dilation with CRE balloon(15–16.5–18 mm). d X-ray
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shows large balloon expanded. e Large biliary orifice can be seen. f Large bile duct stone removal without mechanical lithotripsy (ML)
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defined as the total time between insertion and withdrawal of the endoscope. The fluoroscopy time was automatically calculated by the fluoroscopy unit in the ERCP room. Statistical Analysis The modified intention-to-treat analysis (full analysis set) included all patients excluding those in whom an unsuccessful cannulation occurred (whose data were censored at that time). Patients with protocol violations were considered in the modified intention-to-treat analysis to have had treatment failure. For the per-protocol analysis, only patients who received treatment according to the protocol were included. Data are presented as the mean ± SD or median with range. Categorical variables were compared with the use of the chi-square test. Continuous variables were compared with the use of the t test. All reported P values were twotailed, and P values of \0.05 were considered to indicate statistical significance. The analysis was conducted using SPSS statistical software, version 17.0 (SPSS Institute, Cary, NC, USA).
Table 1 Baseline characteristics of the patients Characteristics
sEST ? EPBD (n = 232)
EST (n = 230)
P value
Sex (M/F)
96/136
87/143
0.435
61.8 ± 16.7
60.6 ± 16.6
0.421
Age (years) Mean ± SD Clinical presentation 88 (37.9 %)
92 (40 %)
0.648
Periampullary diverticulum
Acute cholangitis
93 (40 %)
102 (44.3 %)
0.354
Gallstone
70 (30.2 %)
81 (35.2 %)
0.248
Post-cholecystectomy
74 (31.9 %)
82 (35.7)
0.393
Billroth I reconstruction
5 (2.2 %)
4 (1.7 %)
0.505
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, M male, F female, SD standard deviation
Table 2 Baseline cholangiographic characteristics of the patients Characteristics
sEST ? EPBD
EST
P value
13.2 ± 3.7
12.7 ± 3.5
0.143
Debris
23 (10.1 %)
25 (11 %)
0.748
B2
136 (59.6 %)
144 (63.4 %)
0.406
C3
69 (30.3 %)
58 (25.6 %)
0.263
Largest bile duct diameter (mm) Mean ± SD Number of stones
Results Patients and Enrollment From 1 May 2008 to 30 April 2011, a total of 478 patients were enrolled in the study; 16 patients were excluded before randomization (Fig. 1). Patient characteristics are summarized in Table 1. The baseline characteristics were well balanced. A total of 232 patients (male:female ratio, 96:136; mean age, 61.8 years) were randomized to the sEST ? EPBD group, and 230 (male:female ratio, 87:143; mean age, 60.6 years) were randomized to the EST group. There were no differences between the sEST ? EPBD and EST groups with regard to acute cholangitis (37.9 vs. 40 %, respectively; P = 0.648), periampullary diverticulum (40 vs. 44.3 %, respectively; P = 0.354), gallstones (30.2 vs. 35.2 %, respectively; P = 0.248), postcholecystectomy (31.9 vs. 35.7 %, respectively; P = 0.393), and Billroth-I reconstruction (2.2 vs. 1.7 %, respectively; P = 0.505). The statistical analysis was repeated by per-protocol analysis. There were no differences in the baseline characteristics, success rate, or complication rate between the two groups. Clinical Outcomes There was no statistically significant difference in the cannulation success rate between the two groups. Precut
Largest size of stones (mm) \12
138 (60.5 %)
141 (62.1 %)
0.728
C12
90 (39.5 %)
86 (37.9 %)
0.728
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
sphincterotomy and the double-guidewire technique were performed in cases of difficult cannulation. According to the initial diagnostic cholangiogram, the CBD was dilated in all patients. There were no statistically significant differences in the stone size, stone number, or CBD diameter between the two groups (Table 2). There was no statistically significant difference in the final clearance of CBD stones between the sEST ? EPBD and EST groups (97.4 vs. 94.7 %, respectively; P = 0.146) (Table 3). When the stone was \12 mm, success rate was similar between groups (97.1 vs. 99.3 %, respectively; P = 0.354). When the stone was ‡12 mm, success rate differed between the two groups (97.8 vs. 87.3 %, respectively; P = 0.021). However, in the first session, the stone clearance rate was significantly higher in the sEST ? EPBD group than in the EST group (87.7 vs. 71.4 %; P \ 0.05). ML was more frequently performed in the EST group than in the sEST ? EPBD group (35.2 vs. 12.3 %, respectively; P \ 0.05).
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sEST ? EPBD
Table 4 Complications within 24 h in the two groups EST
P value
Complications
sEST ? EPBD
EST
P value 0.544
Complete removal of stone
222 (97.4 %)
215 (94.7 %)
0.146
Acute pancreatitis
12 (5.3 %)
15 (6.6 %)
Success rate with stone C 12 mm
88 (97.8 %)
75 (87.3 %)
0.021
Mild
7 (3.1 %)
10 (4.4 %)
Success rate with stone \ 12 mm
134 (97.1 %)
140 (99.3 %)
0.354
Moderate
5 (2.2 %)
5 (2.2 %)
Success rate in the first session
200 (87.7 %)
162 (71.4 %) \0.05
Severe
0
0
Rate of ML
28 (12.3 %)
80 (35.2 %)
Hemorrhage
4 (1.8 %)
12 (5.3 %)
0.041
Perforation
0
0
-
Total
16 (7.0 %)
27 (11.9 %)
0.075
\0.05
Procedure time (min) Mean ± SD
38.6 ± 15.5
47.1 ± 20.2
\0.05
Radiation exposure time (min) Mean ± SD
17.3 ± 7.0
26.5 ± 10.8
\0.05
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
The total procedure time and fluoroscopy time included the cannulation session and stone removal session. The procedure time and fluoroscopy time differed significantly between the two groups (38.6 ± 15.5 vs. 47.1 ± 20.2 min, P \ 0.05 and 17.3 ± 7.0 vs. 26.5 ± 10.8 min, P \ 0.05, respectively).
Complications and Adverse Events The overall complication rates (Table 4) were not significantly different between the sEST ? EPBD and EST groups (7.0 vs. 11.9 %, respectively; P = 0.075). The rates of pancreatitis were not significantly different between the two groups (5.3 vs. 6.6 %, respectively; P = 0.544), and all cases were either mild or moderate. In terms of hemorrhage, bleeding occurred in 4 patients (1.8 %) in the sEST ? EPBD group and 12 patients (5.3 %) in the EST group with a statistically significant difference (P = 0.041). No patient required surgical intervention or died as a result of the ERCP-induced bleeding. All bleeding was managed conservatively using saline-epinephrine injections, a retrieval balloon, or dilating balloon compression. No death and perforation complications were observed in either group. One-year complications (Table 5) included right upper quadrant abdominal pain, bile duct stone recurrence, cholangitis, acute cholecystitis, bile duct malignancy, and pancreatitis. Complications occurred in 18 patients in the sEST ? EPBD group and in 23 patients in the EST group. Fourteen patients in the sEST ? EPBD group and 16 patients in the EST group had right upper quadrant abdominal pain without fever. Biliary and/or pancreaticrelated problems occurred in four and seven patients in the sEST ? EPBD and EST groups, respectively. There were no statistically significant differences in these parameters.
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Complication evaluation according to Cotton’s criteria. Hemorrhage include acute endoscopic bleeding and post-procedure bleeding sEST ? EPBD limited endoscopic sphincterotomy plus Endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy, SD standard deviation
Table 5 One-year complications in the two groups Complications
sEST ? EPBD
EST
P value
Abdominal pain
14 (6.14 %)
16 (7.0 %)
0.696
Biliary problems
3 (1.32 %)
5 (2.2 %)
0.503
Acute cholangitis
2 (0.88 %)
2 (0.88 %)
Acute cholecystitis
0
1 (0.44 %)
CBD stone recurrence
1 (0.44 %)
2 (0.88 %)
Acute pancreatitis
1 (0.44 %)
2 (0.88 %)
Biliary malignancy
0
0
Total
18 (7.9 %)
23 (10.1 %)
0.623 0.405
sEST ? EPBD small endoscopic sphincterotomy plus endoscopic papillary balloon dilatation, EST endoscopic sphincterotomy
Discussion EST has been widely accepted as a standard method for CBD stone removal [1, 2]. Although the safety of EST has been proven in many studies, this technique carries procedure-related risks (5–11 %) [3, 4] such as acute pancreatitis, hemorrhage, and perforation. Attention has also been given to the potential long-term complications of sphincterotomy, such as an increased incidence of ascending cholangitis and recurrence of bile duct stones. In most cases however, EST still remains the first-choice treatment [10]. Ersoz et al. [5] first reported the use of EST followed by large-diameter (15- to 20-mm) EPBD as an alternative management technique for large bile duct stones. Several studies [11–16] subsequently confirmed that sEST ? EPBD can improve efficiency and reduce complications. Difficulty in clearing bile duct stones is caused by the presence of large stones, multiple stones, barrel-shaped stones, and tapering of the distal CBD. For large CBD stones, sEST ? EPBD is an effective and safe treatment.
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In addition, the procedure can be completed with a shorter procedure time and fluoroscopy time than EST alone. For very small stones, tapering of the distal CBD may account for the difficulty of stone removal. When a dilation balloon is used, both the papillary sphincter and distal bile duct are dilated, allowing for easy removal of the stone with a retrieval balloon. These advantages raise the question of whether the indications for sEST ? EPBD can be expanded. No previous studies have examined this question. In our study, the ultimate success rate was similar between the sEST ? EPBD and EST groups. sEST ? EPBD is an effective treatment for CBD stones. Our data showed that the success rate of sEST ? EPBD for complete clearance of bile duct stones in the first ERCP session was higher than that of EST, although there was no statistically significant difference in the ultimate success rate. When the stone was \ 12 mm, success rate was similar between groups. When the stone was ‡ 12 mm, success rate was significantly higher in the sEST ? EPBD group than in the EST group. The results suggest sEST ? EPBD is effective for CBD stones. Importantly, in the first session, the stone clearance rate was significantly higher in the sEST ? EPBD group than in the EST group. The result suggests sEST ? EPBD can remove the CBD stones with high efficiency. The main causes of incomplete stone extraction in the first session were large stones, multiple stones, or tapering of the distal CBD. Furthermore, the need for ML was significantly lower in the sEST ? EPBD group than in the EST group. For this reason, we considered that the orifice after sEST ? EPBD made it possible to more easily remove bile duct stones compared with EST alone. The use of ML may create many stone fragments that are difficult to clear. Because few patients in the sEST ? EPBD group needed ML and underwent whole stone removal, the total procedure time and fluoroscopy time were significantly shorter than those in the EST group. These results are similar to those in a previous retrospective analysis [12]. Although the indications were expanded, these data are in agreement with previous published results. sEST ? EPBD is not only effective, but also highly efficient. However, will using balloon dilation in all cases, even for small stones, unnecessarily increase the cost to patients? Theoretically, a large orifice after sEST ? EPBD makes it possible to more easily remove CBD stones than with EST alone. The stones can only be removed with a retrieval balloon; the retrieval basket is not necessary. And the need for ML was significantly lower in the sEST ? EPBD group than in the EST group. Importantly, the total procedure time and fluoroscopy time are also short. The method will not increase the cost to patients. Although the procedure-related short-term complications were not significantly different between the two
groups, the complication rate in the sEST ? EPBD group was lower. Although about 40 % of the patients had perivaterian diverticuli, perforations were not encountered in any patients who underwent sEST ? EPBD or EST. Perivaterian diverticuli are a cause of CBD stones and can increase the risk of perforation of full EST. One patient in the EST group could not undergo EST because of the presence of perivaterian diverticuli. Because a nasal biliary drainage catheter was routinely inserted at the end of the procedure, no cholecystitis or cholangitis occurred in either group. Endoscopic biliary drainage is used for prevention of complications such as cholecystitis and cholangitis. We also take a cholangiogram to confirm complete clearance through the nasobiliary drainage tube. Although this may increase the cost to patients, safety of the procedure is more important. In several other reports [12–16], the risk of PEP following sEST ? EPBD was lower than that following EST. The rate of acute pancreatitis was similar between the sEST ? EPBD and EST groups. The reason for this may be related to multiple factors, such as age, pancreatic stent placement, and the wire-guided cannulation technique. Bleeding occurred in four patients (1.8 %) in the sEST ? EPBD group and 12 patients (5.3 %) in the EST group with a statistically significant difference in our study. Freeman et al. [3] and Cotton et al. [9] reported a bleeding rate of 1–3 % in the EST group. The bleeding rates in other recent studies were similar to those of our study. No patients required surgical intervention or died as a result of the ERCP-induced bleeding. All bleeding was managed conservatively. We suspect that the difference in the bleeding rates between the sEST ? EPBD and EST groups may have been the result of balloon compression of the sphincterotomy site. This may be why patients who underwent sEST ? EPBD had a lower incidence of endoscopically observed bleeding. One-year complications [17–21] included right upper quadrant abdominal pain, bile duct stone recurrence, cholangitis, acute cholecystitis, bile duct malignancy, and pancreatitis. There were no statistically significant differences in these parameters. To obtain a much more thorough understanding of long-term complications, the follow-up study is necessary. In conclusion, dilation-assisted stone extraction, with its higher first-session success rate and shorter procedure time and fluoroscopy time, is more efficient than EST. Dilationassisted stone extraction is an alternative method for removal of CBD stones. The balloon-equipped sphincterotome may be used in the future. Acknowledgments We are indebted to Zilong Lu of the Shandong Center for Disease Control and Prevention for his help with the statistical data analysis. Conflict of interest
None.
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