Background and study aims To develop a pancreatobiliary endoscopic guidewire with good clinical performance, an understanding of its structure is necessary. This study aimed to investigate the structural factors influencing the clinical performance of pancreatobiliary endoscopic guidewires. Methods Eight types of 0.025-inch guidewires were evaluated. The following structural properties were measured: tip length, tip deflection height, tip weight (TW), ratio of tip core weight to TW, shaft coating type (flat or uneven), outer diameter, and core wire diameter (CWD). Four performance tests were conducted to evaluate shaft stiffness as bending force (BF), shaft lubricity as friction force (FF), torque response as torque response rate (TRR), and seeking ability as total insertion success (TIS) in a technical test using a 3D bile duct model. The correlation coefficients of each variable were analyzed. Results The BF and CWDs were strongly correlated, as well as the FF and CWDs and BF. Among the guidewires with similar CWDs, the guidewires with uneven coating had significantly lower FF than those with flat coating. The TRR was strongly correlated with the CWDs; furthermore, guidewires with lower FF had better TRR. TIS was strongly correlated with the TRR, TWs, and ratio of the tip core weight to TW. Conclusions CWD affects shaft stiffness; CWD and coating type affect shaft lubricity and torque response. Because TRR and TW are correlated with seeking ability, an appropriate combination of core wire thickness, TW, and coating design is required to develop a guidewire with good seeking ability.

Various guidewires are used for biliary cannulation, and each one has its own characteristics affecting its effectiveness. This study aimed to measure the basic properties and evaluate the effectiveness of a newly developed 0.025-inch guidewire for selective biliary cannulation.

A total of 190 patients at five referral hospitals were randomly allocated to undergo selective biliary cannulation using the newly developed guidewire (NGW group, n = 95) or a conventional guidewire (CGW group, n = 95). The primary outcome was the selective biliary cannulation rate in naïve papillae. The secondary outcome was to measure the NGW basic properties, compare them with those of the CGW, and analyze the importance of basic property differences.

There were no significant differences between the groups in the baseline characteristics. The primary outcome (75.8% vs. 84.2%, p = 0.102) and adverse event rate (6.3% vs. 4.2%, p = 0.374) were similar in both groups. However, compared with the CGW group, the NGW group showed a higher number of ampulla contacts (2.58 vs. 2.02, p = 0.011) and longer cannulation time (216.5 vs. 135.1 s, p = 0.016). Furthermore, the NGW group had higher maximum friction (34.6 ± 1.34 vs. 30.2 ± 4.09), lower stiffness, and better elastic resiliency. In the multivariate analysis, a curved-tip GW (OR = 0.26, 95% CI 0.11-0.62, p = 0.002) and normal papillary shape (OR = 0.39, 95% CI 0.17-0.86, p = 0.021) were contributing factors for successful selective biliary cannulation.

The NGW group had high friction and low stiffness, characteristics affecting biliary cannulation. Clinically, the NGW group had similar success and adverse event rates as the CGW, but they showed a higher number of ampulla contacts and longer cannulation time.

Wire-guided cannulation (WGC) during endoscopic retrograde cholangiopancreatography (ERCP) is a selective biliary cannulation technique aimed at improving the successful selective biliary cannulation rate and reducing the rate of post-ERCP pancreatitis (PEP) incidence. This study aimed to evaluate the effectiveness of angled-tip guidewires (AGW) vs. straight-tip guidewires (SGW) for biliary cannulation via WGC by a trainee.

We conducted a prospective, single-center, open-labeled, randomized, and controlled trial. Fifty-seven patients were enrolled in this study and assigned randomly to two groups (Group A to S and Group S to A). In this study, we started selective biliary cannulation via WGC with an AGW or an SGW for 7 min. If cannulation was unsuccessful, the other guidewire was used, and cannulation was continued for another 7 min (cross-over method).

The selective biliary cannulation success rate over 14 min was significantly higher with an AGW compared with an SGW over 14 min (57.8% vs. 34.3%, p = 0.04) and for the second 7-min segment (36.4% vs. 0%, p = 0.04). No significant difference was found for adverse events such as pancreatitis between the two guidewires.

Our results suggest that an AGW is recommended for WGC performed by a trainee.

Endoscopic retrograde cholangiopancreatography (ERCP) is the mainstay for interventional treatment of biliopancreatic diseases, and guidewires are decisive for successful treatment.

A randomized, multicenter, open-label study was conducted in patients in whom a guidewire was required in ERCP. Success rate and duration of the investigation were evaluated by randomly applying hydrophilic guidewires with a straight tip (ST) or an angled tip (AT) configuration, with normal (type NF) or enhanced (type EF) flexibility. Randomization was stratified by indication, i.e., stricture of the intra-hepatic bile ducts, stricture of the extrahepatic bile ducts, obstruction by bile duct stones, or interventions involving the pancreas. Cross-over was allowed if the initially allocated guidewire did not result in treatment success.

Four hundred fifty-three patients were included, and 422 were finally analyzed. In 363 procedures (86%), the initially allocated wirés use resulted in treatment success. The success rate for using a guidewire with an angled tip configuration was 87.5 vs. 79.9% in a straight tip configuration (p = 0.049), and in negotiating an intrahepatic stricture the success rate was 90.7 vs. 69.1%, respectively (p = 0.008). No significant differences were observed in other indications. Procedural duration time did not differ in between the treatment groups.

ERCP guidewires with an angled tip were more frequently successful when compared to straight tipped wires and most successful in treating intrahepatic strictures. Guidewires with standard vs. enhanced tip flexibility showed equal success rates in all indications.

Despite improvements in endoscopic technologies and accessories, development of advanced endoscopy fellowship programs, and advances in ancillary imaging techniques, biliary cannulation in endoscopic retrograde cholangiopancreatography (ERCP) can still be unsuccessful in up to 20% of patients, even in referral centers. Once cannulation has been deemed to be difficult, the risk of post-ERCP pancreatitis and technical failure inherently increases. A number of factors, including endoscopist experience and patient anatomy, have been associated with difficult biliary cannulation, but predicting a case of difficult cannulation a priori is often not possible. Numerous techniques such as pancreatic guidewire and stenting, early pre-cut, and rendezvous may be employed when standard approaches fail. Data regarding the rate of success and adverse events of these techniques have been variable, though most studies suggest that pancreatic duct stenting generally reduces the rate of post-ERCP pancreatitis in instances of difficult biliary cannulation. Here we provide a review on difficult biliary cannulation and discuss how the choice of which techniques to employ and how to best employ them should be individualized and take into account the skill of the endoscopist, the disorder being treated, the anatomy of the patient, and the available biomedical literature.

Wire-guided cannulation has been widely accepted as a useful technique for achieving selective biliary access because it has significantly increased the success rate of biliary cannulation compared with conventional contrast-assisted cannulation. Unlike conventional guidewires with a straight tip, a loop-tip guidewire (LGW) has a closed distal loop that may facilitate less traumatic access through the epithelial folds of the intra-duodenal biliary segments. The aim of this study was to compare the performance of a LGW with a straight-tip guidewire (SGW) in achieving successful selective biliary cannulation.

From December 2014 to December 2015, we performed 192 wire-guided biliary cannulations for a naïve papilla in a randomized controlled trial. Patients were randomly assigned to the LGW group (n = 96) or the SGW group (n = 96). Our study protocol did not include crossover to the other guidewire arm if randomized wire-guided cannulation proved unsuccessful within the first 10 min.

There was no significant difference in primary successful biliary cannulation between the two groups (LGW group: 86.5%; SGW group: 77.1%; p = 0.134). The rate and the mean number of unintentional pancreatic duct cannulations during wire-guided biliary cannulation were significantly lower in the LGW group than in the SGW group (LGW group: 14.6%; SGW group: 28.1%; p = 0.034; LGW group: 0.2 ± 0.5; SGW group: 0.6 ± 1.3; p = 0.007). Post-ERCP pancreatitis developed in 5.2% of patients in the LGW group and 8.3% of patients in the SGW group (p = 0.567).

The biliary cannulation rate of the LGW was not significantly different from those of conventional guidewires. Use of the LGW was associated with a lower rate of unintentional pancreatic duct cannulation during wire-guided biliary cannulation than use of the SGW.

Over the past 2 decades, it increasingly has been recognized that endoscopic retrograde cholangiopancreatography (ERCP) is the most predictable provocateur of acute pancreatitis, with an incidence of more than 15% in high-risk patients. For this reason, there has been considerable interest in the effect of periprocedural drug administration as well as different ERCP techniques on both the incidence and severity of post-ERCP pancreatitis. Although many agents and techniques have shown promise in small clinical studies, the majority of these have failed to yield consistent benefit in larger randomized patient groups. This review summarizes the data on medications and ERCP techniques that have been studied for the prevention of post-ERCP pancreatitis.

Wire-guided cannulation has become a common biliary cannulation technique worldwide. Different guidewires with various tip shapes and materials have been reportedly used for wire-guided cannulation. However, there are apparently no studies reporting changes in the biliary cannulation rate according to the type of guidewire used.

We evaluated the effectiveness of the J-tip guidewire for biliary cannulation.

We conducted a prospective, multicenter, controlled study involving patients with a native papilla who required biliary cannulation. We allocated the patients to the J-tip guidewire or angled-tip guidewire groups (groups J and A, respectively). If biliary cannulation was not achieved within 10 min, the GW was changed and cannulation was continued.

Groups J and A consisted of 66 and 65 enrolled patients, respectively. The biliary cannulation rate with a single guidewire for the first 10 min was 84.8 % (56/66) for group J and 80.0 % (52/65) for group A. The final success rate for biliary cannulation was 100 % in both groups. The mean times necessary for biliary cannulation were 285.8 and 267.6 s in group J and group A, respectively. The incidence rates of complications (i.e., all mild pancreatitis) were 3.0 % (2/66) and 6.2 % (4/65) in group J and group A, respectively. The mean amylase concentrations were 168.0 and 297.7 IU/L in group J and group A, respectively. There were no significant differences in any results between both groups.

The biliary cannulation rate of the J-tip guidewire was not significantly different from those of standard guidewires.