Biliary spontaneous dislodgement spiral stent for patients who underwent mechanical lithotripsy

Table 1 Baseline characteristics and clinical information of the biliary spontaneous dislodgement spiral stent and nasobiliary groups, n (%)

	BSDSS group (n = 21)	Nasobiliary tube group (n = 28)	P value
Age, mean ± SD, yr	64 ± 16	67 ± 19	0.5725
Sex, male/female	11/10	13/15	0.6806
Diagnosis			0.9517
Biliary colic	6 (28.6)	10 (35.7)
Obstructive jaundice	7 (33.3)	8 (28.6)
Acute cholangitis1	6 (28.6)	7 (25.0)
Acute pancreatitis1	2 (9.5)	3 (10.7)
Comorbidity2	10 (47.6)	18 (64.3)	0.2436
Gallbladder status			0.4107
Post cholecystectomy	12 (57.1)	13 (46.4)
Cholecystectomy after ERCP	2 (9.5)	1 (3.6)
Gallbladder stones in situ	5 (23.8)	6 (21.4)
No gallbladder stones	2 (9.5)	8 (28.6)
Previous EST	2 (9.5)	6 (21.4)	0.4387
Periampullary diverticulum	11 (52.4)	12 (42.9)	0.5096
Maximum CBD diameter, median (IQR), mm	13 (12-16)	15 (13-15)	0.2148
Maximum stone diameter, median (IQR), mm	13 (11-16)	12 (12-15)	0.5818
Minimum stone diameter, median (IQR), mm	10 (9-12)	12 (10-12)	0.7618
Stones number, < 3/≥ 3	14/7	25/3	0.0766
ERCP modalities for stone removal			0.5957
ML3	1 (4.8)	4 (14.3)
EST + ML	3 (14.3)	6 (21.4)
EPBD + ML3	1 (4.8)	2 (7.1)
EST + EPBD + ML	16 (76.2)	16 (57.1)
Residual debris4	1 (4.8)	5 (17.9)	0.2197

¹Endoscopic retrograde cholangiopancreatography was performed when acute cholangitis and acute pancreatitis were controlled;

²Hypertension, coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease, liver cirrhosis, neoplastic diseases in other systems;

³These patients underwent endoscopic sphincterotomy for stone removal previously;

⁴Residual debris was detected by abdominal ultrasound in the only one patient in the biliary spontaneous dislodgement spiral stent group; Residual debris was detected by postoperative cholangiography in four patients in the nasobiliary tube group, while the remaining one patient was confirmed by abdominal ultrasound owing to dislocation of the nasobiliary tube. All these 6 patients underwent additional endoscopic retrograde cholangiopancreatography for debris removal;

⁵Student’s t test;

⁶χ² test;

⁷Fisher exact test;

⁸Mann-Whitney U-test. BSDSS: Biliary spontaneous dislodgement spiral stent; ERCP: Endoscopic retrograde cholangiopancreatography; CBD: Common bile duct; IQR: Interquartile range; EST: Endoscopic sphincterotomy; ML: Mechanical lithotripsy; EPBD: Endoscopic papillary balloon dilation.

Table 2 Clinical outcomes of the biliary spontaneous dislodgement spiral stent and nasobiliary tube groups, n (%)

	BSDSS group (n = 21)	Nasobiliary tube group (n = 28)	P value
Technical success	21 (100)	28 (100)	-
Overall post-ERCP adverse events	1 (4.8)	5 (17.9)	0.2194
Cholangitis	0 (0)	0 (0)	-
Pancreatitis1	1 (4.8)	1 (3.6)	1.0004
CBD stone recurrence	0 (0)	1 (3.6)	1.0004
Other events2	0 (0)	3 (10.7)	0.2504
Follow-up duration, median (IQR), mo	19 (17-22)	18 (15-21)	0.3655
Drainage time3, median (IQR), d	3 (3-5)	4 (2-5)	0.9345
Postoperative stay, median (IQR), d	4 (3-6)	5 (3-7)	0.2235

¹Pancreatitis was graded as mild in both groups;

²There was no biliary spontaneous dislodgement spiral stent (BSDSS) retention in the BSDSS group, while self-extraction (n = 2) and dislocation (n = 1) of the nasobiliary tube was noted in three patients in the nasobiliary tube group;

³Drainage time was defined as the duration from insertion to evacuation in the BSDSS group and the duration from insertion to extraction in the nasobiliary tube group;

⁴Fisher exact test;

⁵Mann-Whitney U-test. BSDSS: Biliary spontaneous dislodgement spiral stent; ERCP: Endoscopic retrograde cholangiopancreatography; CBD: Common bile duct; IQR: Interquartile range.