Electrosurgical safety of guide wires during endoscopic sphincterotomy

Japan Gastroenterological Endoscopy Society guidelines for endoscopic sphincterotomy

The Japan Gastroenterological Endoscopy Society (JGES) has recently compiled guidelines for endoscopic sphincterotomy (EST) using evidence-based methods. Content regarding actual clinical practice, including detailed endoscopic procedures, instruments, device types and usage, has already been published by the JGES postgraduate education committee in May 2015 and, thus, in these guidelines we avoided duplicating such content as much as possible. The guidelines do not address pancreatic sphincterotomy, endoscopic papillary balloon dilation (EPBD), and endoscopic papillary large balloon dilation (EPLBD). The guidelines for EPLBD are planned to be developed separately. The evidence level in this field is often low and, in many instances, strong recommendation has to be determined on the basis of expert consensus. At this point in time, the guidelines are divided into six items including indications, techniques, specific cases, adverse events, outcomes, and postoperative follow up.

Endoscopic resection of ampullary adenoma after a new insulated plastic pancreatic stent placement: a pilot study

BACKGROUND AND AIM

Although pancreatic stent insertion is recommended for the prevention of post-procedure pancreatitis during endoscopic papillectomy, insertion of the stent after the procedure can be technically difficult. The aim of the present study was to determine the feasibility and safety of inserting a newly developed insulated pancreatic stent before endoscopic papillectomy.

METHODS

We conducted a prospective pilot study involving 11 consecutive patients with adenomas of the major duodenal papilla. After a 5F polytetrafluoroethylene-insulated pancreatic stent was inserted through the tumor, the stent and tumor were simultaneously grasped with a snare. After resection of the tumor with the stent in place, the tumor was incised perpendicularly along the edge of the stent for retrieval of the specimen.

RESULTS

In all patients, the insulated pancreatic stents were successfully inserted before endoscopic papillectomy and were resistant to electrical current; retrieval of the specimen was technically feasible and successful without stent migration. There were no stent-related complications, but five papillectomy-related complications (including mild bleeding [n = 4] and late papillary stenosis [n = 1]) occurred without any episodes of acute pancreatitis or perforation.

CONCLUSIONS

Pre-resection stenting with a polytetrafluoroethylene-insulated stent in patients with adenomas of the major duodenal papilla is a feasible and useful technique to prevent pancreatitis.

Current induction in a fiberglass guidewire compared to conventional wires during simulated papillotomy

BACKGROUND

Current induced in a guidewire during papillotomy poses a danger of injury to the bile duct. We measured currents induced in three commercially available guidewires and a prototype fiberglass wire during simulated sphincterotomy under standard and nonstandard conditions.

METHODS

Blended current at 55 W was applied to a double-lumen papillotome grounded through a 1000 omega resistor. For extreme conditions, power was increased to 70 W using a single-lumen papillotome. Fault conditions were created with a break in the insulation at the distal end of each wire. Guidewire-induced current was measured, and safety calculations performed for adherence to accepted standards for electrosurgical devices.

RESULTS

Induced current was within safety limits for all wires tested under standard conditions. With insulation faults, one of the commercially available wires was unsafe. Under extreme conditions, with or without faults, the three commercial wires produced currents ranging from 9% to 225% above acceptable levels, while only the prototype wire remained safe.

CONCLUSIONS

Most guidewires contain metal cores that function as capacitors. Because its core is primarily fiberglass, the prototype wire generates less induced current under nonstandard conditions, thus achieving a greater margin of safety during wire-guided sphincterotomy.

Consistent improvement in sphincterotome orientation with manual grooming

BACKGROUND

During ampullary cannulation with standard sphincterotomes, wire orientation is frequently to the right of 0 and can not always be rotated to the 12 o'clock ideal. It is not known if the presence of a wire guide alters a sphincterotome's orientation or if grooming in a standardized manner improves the orientation in the majority of cases.

METHODS

The intra-ampullary range of orientation of a double channel sphincterotome was prospectively evaluated before and after catheter grooming in 25 patients undergoing ERCP. The range of orientation was also measured with and without an indwelling biliary wire guide in 14 cases.

RESULTS

The maximal right orientation of the untrained sphincterotomes was 35 +/- 16 degrees; with a wire guide it was 33 +/- 22 degrees. Maximal left orientation was 17 +/- 16 degrees, wire guided it remained 19 +/- 14 degrees. Manual grooming shifted the mean maximal left orientation of the sphincterotomes to -37 +/- 28 degrees (p < 0.0001), permitting 80% of groomed sphincterotomes to achieve a 0 (12 o'clock) orientation and 100% to orient 10 degrees or less from zero.

CONCLUSIONS

The presence of the wire guide did not alter the orientation of the sphincterotome. Because manual grooming reliably improved the orientation of double-channel sphincterotomes, it should be routinely performed before their use.