Is the Isolated-Tip Needle-Knife Precut as Effective as Conventional Precut Fistulotomy in Difficult Biliary Cannulation?

Abstract

Background/aims: Needle-knife precut fistulotomy (NK-F) is a well-known freehand technique for difficult biliary cannulation (DBC). Another approach involves the use of Iso-Tome^®, a modified precutting device with an insulated needle tip to prevent direct thermal injury. This comparative study aimed to evaluate the efficacy of the Iso-Tome^® precut (IT-P) compared to that of NK-F for DBC.

Methods: Patients with a naïve papilla who underwent early IT-P or NK-F for DBC were enrolled. DBC was defined as failure to achieve selective biliary access by wire-guided cannulation despite 5 minutes of attempted cannulation, ≥5 papillary contacts, or a hooknose-shaped papilla. The primary endpoint was the primary technical success rate, which was based on a noninferiority model.

Results: A total of 239 DBC cases were enrolled. The primary technical success rates were 74.7% (89/119) in the IT-P group and 91.6% (110/120) in the NK-F group (lower limit of 90% confidence interval, -0.23; p=0.927 for a noninferiority margin of 10%). The total technical success rates were 87.4% and 95.0%, respectively (p=0.038). The mean precutting times for successful biliary access were 11.2 minutes for IT-P and 7.3 minutes for NK-F (p<0.01). The procedure-related adverse event rates were 9.2% for IT-P and 5.8% for NK-F (p=0.318). The rates of post-endoscopic retrograde cholangiopancreatography pancreatitis were 4.2% and 2.5%, respectively (p=0.499).

Conclusions: IT-P failed to exhibit noninferiority compared with NK-F regarding the primary technical success rate of DBC, but there was no difference in the frequency of adverse events.

Keywords: Biliary; Cannulation; Iso-Tome; Needle-knife; Precut.

Fig. 1

Flow diagram of the study ERCP, endoscopic retrograde cholangiopancreatography; PTBD, percutaneous transhepatic biliary drainage; PTGBD, percutaneous transhepatic gallbladder drainage; EUS-BD, endoscopic ultrasound-guided biliary drainage.

Fig. 2

Endoscopic Iso-Tome® precut technique. (A) Duodenoscopy showed a prominent ampulla of Vater (AV) with erythema due to primary cannulation failure. The Iso-Tome® was introduced at the orifice to perform the precut. (B) The isolated tip of the Iso-Tome® was placed at the orifice of the AV, and then precutting was performed with slight upward tension in the 11 to 12 o’clock direction. (C) Following successful precut, the intrapapillary mucosa was noted, and conventional guidewire cannulation was attempted. (D) Successful wire-guided bile duct cannulation using a papillotome was achieved.

Fig. 3

Endoscopic conventional needle-knife (NK)-fistulotomy technique. (A) Duodenoscopy showed a bulging ampulla of Vater (AV). (B) NK incision started at the maximal bulging point of the papillary roof of the AV. (C) Following small incremental incisions in the papillary roof, guidewire insertion was attempted using NK. (D) Successful bile duct cannulation was achieved.

Fig. 4

Various ampulla of Vater (AV) configurations. (A) Non-prominent type: a small papilla without marked oral protrusion of the papillary roof. (B) Prominent type: more prominent elevation of the papillary roof. (C) Bulging type: marked swelling from the bulge in the papillary roof to the oral ridge of the duodenal wall. (D) Hook-nose type: a huge bulging type with an invisible AV orifice due to a hook-nose-shaped protrusion. (E) Distorted type: AV of unusual shape and distorted position due to tumor invasion or compression.