Use of Touch and no Touch Guide-wire Techniques for Deep Biliary Cannulation: the TNT Study

The most common technique used to achieve primary deep biliary cannulation is the standard contrast-assisted method, in which a catheter or sphincterotome is introduced into the papilla in the direction of the bile duct and a contrast medium injected to confirm that the duct has been cannulated.

The biliary guidewire cannulation technique consists of the introduction of a guide-wire into the bile duct instead of contrast injection as the first maneuver.

The benefit of this technique, compared with classic contrast cannulation, has been demonstrated in several studies which show similar results and have been analyzed in a recent meta-analysis, including 5 studies and 1762 patients, and demonstrating that the use of the guide-wire technique significantly improved the primary cannulation rate from 74.9% to 85.3%. More importantly, significantly reduced the incidence of PEP from 8.6% to 1.6%.

There are several variations of this technique; the tip of the sphincterotome is inserted initially a few millimeters through the papillary orifice and then introduce the guide-wire to the target ("touch technique"). Another variation is direct cannulation with the guide-wire hovering a few millimeters through the catheter or sphincterotome ("no touch technique").

To date, there are no randomized controlled trials comparing the two above described way to access to biliary duct regarding efficacy and rate of complications.

Inclusion criteria

• Age 18 or older
• Clinical symptoms, laboratory findings and radiological evidences of biliary disease
• Willing and able to comply with the study procedures and provide written informed consent to participate in the study

Exclusion criteria

• Age <18 yars
• Patients with previous sphincterotomy
• Patients with previous papillary endoscopic balloon dilation
• Presence of a previously placed plastic or metal biliary stent
• Presence of any esophageal or gastro/duodenal stent
• Pancreatic or ampullary cancer, proven by imaging and/or cytology and/or histology, are excluded as PEP is very uncommon in these subgroups and tumour-related anatomical variation may alter cannulation technique (consider substratify results for this subgroup, but exclude if duodenal stenosis precludes an attempt on the papilla)
• Patients with surgically altered anatomy (Bilroth II gastrectomy and Roux en Y anastomosis) are excluded as cannulation technique is fundamentally different from that in normal anatomy
• Presence of a diverticular papilla
• Presence of a duodenal stenosis
• Presence of a pancreas divisum
• Patients with contraindication to endoscopic procedures
• Hemodinynamic instability, any acute illness or exacerbation of chronic illness, acute infections.
• Platelet count less than 50,000/mm3 and INR no greater than 1.5 times upper limit of normal
• Inability or refusal to give informed consent.
• Refusal to provide consent