- Email: [email protected]
A user friendly hydrophilic guidewire
stent through the endoscope has provided a more rapid, safer relief of biliary obstruction and has had the added benefit of limiting the size of the hole placed through the liver parenchyma, which I think is of more concern than any of the issues raised by Drs. Tsang, Crampton, and Buto.
2. Miller GL, Laurence BH, McCarthy JH. Cannulation of the cystic duct and gallbladder. Endoscopy 1989;21:223-4. 3. Chespak LW, Ring EJ, Shapiro AJ, Gordon RL, Ostroff JW. Multidisciplinary appraoch to complex endoscopic biliary intervention. Radiology 1989;170:995-7.
Mark Jacobs, MD Manoa Medical Center Havertown, Pennsylvania
Biliary stent migration To the Editor:
A user friendly hydrophilic guidewire To the Editor:
In addition to recent publications in your journaP and elsewhere,2,3 on the use of Glidewires@ (Terumo, Inc.) in ERCP, we would like to report a simple modification of the wires which enables easier control. Glidewires@ have a number of significant advantages compared with conventional guidewires. The strong titanium! nickel alloy core makes them difficult to kink and allows effective torque control of the tip by using a proximal pin vise torque controller (Bard Interventional Products, Billerica, Mass.). It has a very flexible tip, and the hydrophilic polymer coating, when wet, makes the Glidewire@ very slippery-a major advantage when negotiating long, tortuous biliary strictures or the cystic duct. Being slippery, however, presents problems in handling, and it is not uncommon for the assistant to lose control of the wire when advancing or withdrawing it through an endoscopic catheter. Non-ionic contrast within the catheter can reduce the slickness of the wire, and the catheter often needs to be flushed with saline to ensure the smooth passage of the wire-a potential hazard if the catheter is in the pancreatic duct. To overcome these difficulties, we have mechanically stripped the polymer coating from all but the distal 70 em of wire. This significantly improves the operator's control over the wire, as the alloy core is easier to grip with gloves or gauze, while not interfering with its functional capabilities. The uncoated wire remains within the endoscope, eliminating any potential risk from direct mucosal contact with the nickel alloy. In stripping the wire, we found it important to taper the polymer at the junction with the core wire to prevent catching of the leading edge of the catheter and stents as they pass through the endoscope; this was achieved by gently heating and rotating this point of the wire. The wires are then re-sterilized with ethylene oxide. The introduction of hydrophilic polymer coated guidewires represents a significant advance in facilitating endoscopic manipulations within the biliary tree. Stripped Glidewires@ are just that bit more user friendly. Stephen K. Fairley, MD Bernard H. Laurence, MD Sir Charles Gairdner Hospital Nedlands, Western Australia
REFERENCES 1. McCarthy JH, Miller GL, Laurence BH. Cannulation of the
biliary tree, cystic duct and gallbladder using a hydrophilic polymer-coated steerable guide wire. Gastrointest Endosc 1990;36:386-9.
210
Proximal migration of endoscopically placed biliary stents is rare. The presence of a distal flap on straight stents is generally effective in preventing this occurrence. I, 2 We report two episodes of stent migration attributed to the avulsion of the distal flap during stent passage through the 3.8mm working channel of the Pentax (Precision Instrument Corp., Orangeburg, N. Y.) Model ED 3400 therapeutic video duodenoscope. The first patient was a 67 -year-old male who had undergone placement of a 10 French Cotton-Huibregtse stent (CHBS-lO; Wilson-Cook Medical, Inc., Winston-Salem, N. C.) for a symptomatic radiation-induced, distal bile duct stricture. Recurrent symptoms prompted the patient to undergo elective surgery 2 months later, at which time the stent was found to be completely within the bile duct. No distal flap was present. The patient has remained well after surgical bypass of the stricture. The second instance occurred in an elderly woman with recurrent cholangitis, possibly related to a large periampullary diverticulum. A 10 French Cotton-Huibregtse stent had been placed without difficulty. Repeat endoscopic retrograde cholangiography revealed the stent to have migrated completely into the bile duct. After sphincterotomy, a basket extraction of the stent was performed. The distal flap was again noted to be absent. Simulated stent passage subsequently demonstrated that shearing or bending of the distal flap occurred in approximately 50% of the passes. This resulted despite scrupulous attention to avoid bending the flap during insertion, regardless of the use of the positioning sleeve accompanying the stent. In those attempts in which injury to the distal flap occurred, resistance was always felt when the distal end of the stent was 2 to 3 em inside the endoscope. We have confirmed this observation with multiple Pentax Ed 3400 video duodenoscopes at our institution as well as in two other institutions. Analysis of this problem with Pentax representatives revealed that the distal flap would occasionally catch at the junction of the suction and biopsy channels. This difficulty could be avoided by ensuring passage of the distal flap into the channel in the 12-0'clock position. Proximal migration is a potentially serious complication of stent placement resulting in possible cholangitis and difficult stent replacement. Fortunately, the incidence of this complication is rare, occurring in only one of 200 cases of stent placement for pancreatic carcinoma 2 and having a higher frequency when placed for benign strictures. 3 Removal of a migrated stent can prove exceptionally difficult and may necessitate a sphincterotomy. Huibregste 2 describes removal by the inflation of a balloon within the lumen of the stent with subsequent withdrawal. Alternatively, a basket or snare may be placed around the stent in the duct with fluoroscopic guidance. I ,2 GASTROINTESTINAL ENDOSCOPY
2. Miller GL, Laurence BH, McCarthy JH. Cannulation of the cystic duct and gallbladder. Endoscopy 1989;21:223-4. 3. Chespak LW, Ring EJ, Shapiro AJ, Gordon RL, Ostroff JW. Multidisciplinary appraoch to complex endoscopic biliary intervention. Radiology 1989;170:995-7.
Mark Jacobs, MD Manoa Medical Center Havertown, Pennsylvania
Biliary stent migration To the Editor:
A user friendly hydrophilic guidewire To the Editor:
In addition to recent publications in your journaP and elsewhere,2,3 on the use of Glidewires@ (Terumo, Inc.) in ERCP, we would like to report a simple modification of the wires which enables easier control. Glidewires@ have a number of significant advantages compared with conventional guidewires. The strong titanium! nickel alloy core makes them difficult to kink and allows effective torque control of the tip by using a proximal pin vise torque controller (Bard Interventional Products, Billerica, Mass.). It has a very flexible tip, and the hydrophilic polymer coating, when wet, makes the Glidewire@ very slippery-a major advantage when negotiating long, tortuous biliary strictures or the cystic duct. Being slippery, however, presents problems in handling, and it is not uncommon for the assistant to lose control of the wire when advancing or withdrawing it through an endoscopic catheter. Non-ionic contrast within the catheter can reduce the slickness of the wire, and the catheter often needs to be flushed with saline to ensure the smooth passage of the wire-a potential hazard if the catheter is in the pancreatic duct. To overcome these difficulties, we have mechanically stripped the polymer coating from all but the distal 70 em of wire. This significantly improves the operator's control over the wire, as the alloy core is easier to grip with gloves or gauze, while not interfering with its functional capabilities. The uncoated wire remains within the endoscope, eliminating any potential risk from direct mucosal contact with the nickel alloy. In stripping the wire, we found it important to taper the polymer at the junction with the core wire to prevent catching of the leading edge of the catheter and stents as they pass through the endoscope; this was achieved by gently heating and rotating this point of the wire. The wires are then re-sterilized with ethylene oxide. The introduction of hydrophilic polymer coated guidewires represents a significant advance in facilitating endoscopic manipulations within the biliary tree. Stripped Glidewires@ are just that bit more user friendly. Stephen K. Fairley, MD Bernard H. Laurence, MD Sir Charles Gairdner Hospital Nedlands, Western Australia
REFERENCES 1. McCarthy JH, Miller GL, Laurence BH. Cannulation of the
biliary tree, cystic duct and gallbladder using a hydrophilic polymer-coated steerable guide wire. Gastrointest Endosc 1990;36:386-9.
210
Proximal migration of endoscopically placed biliary stents is rare. The presence of a distal flap on straight stents is generally effective in preventing this occurrence. I, 2 We report two episodes of stent migration attributed to the avulsion of the distal flap during stent passage through the 3.8mm working channel of the Pentax (Precision Instrument Corp., Orangeburg, N. Y.) Model ED 3400 therapeutic video duodenoscope. The first patient was a 67 -year-old male who had undergone placement of a 10 French Cotton-Huibregtse stent (CHBS-lO; Wilson-Cook Medical, Inc., Winston-Salem, N. C.) for a symptomatic radiation-induced, distal bile duct stricture. Recurrent symptoms prompted the patient to undergo elective surgery 2 months later, at which time the stent was found to be completely within the bile duct. No distal flap was present. The patient has remained well after surgical bypass of the stricture. The second instance occurred in an elderly woman with recurrent cholangitis, possibly related to a large periampullary diverticulum. A 10 French Cotton-Huibregtse stent had been placed without difficulty. Repeat endoscopic retrograde cholangiography revealed the stent to have migrated completely into the bile duct. After sphincterotomy, a basket extraction of the stent was performed. The distal flap was again noted to be absent. Simulated stent passage subsequently demonstrated that shearing or bending of the distal flap occurred in approximately 50% of the passes. This resulted despite scrupulous attention to avoid bending the flap during insertion, regardless of the use of the positioning sleeve accompanying the stent. In those attempts in which injury to the distal flap occurred, resistance was always felt when the distal end of the stent was 2 to 3 em inside the endoscope. We have confirmed this observation with multiple Pentax Ed 3400 video duodenoscopes at our institution as well as in two other institutions. Analysis of this problem with Pentax representatives revealed that the distal flap would occasionally catch at the junction of the suction and biopsy channels. This difficulty could be avoided by ensuring passage of the distal flap into the channel in the 12-0'clock position. Proximal migration is a potentially serious complication of stent placement resulting in possible cholangitis and difficult stent replacement. Fortunately, the incidence of this complication is rare, occurring in only one of 200 cases of stent placement for pancreatic carcinoma 2 and having a higher frequency when placed for benign strictures. 3 Removal of a migrated stent can prove exceptionally difficult and may necessitate a sphincterotomy. Huibregste 2 describes removal by the inflation of a balloon within the lumen of the stent with subsequent withdrawal. Alternatively, a basket or snare may be placed around the stent in the duct with fluoroscopic guidance. I ,2 GASTROINTESTINAL ENDOSCOPY