Endoscopy 2006; 38(11): 1146-1148
DOI: 10.1055/s-2006-944848
Editorial
© Georg Thieme Verlag KG Stuttgart · New York

Performance, length, and cost of endoscopic retrograde cholangiopancreatography guide wires: which is the best mix of features?

H.  Neuhaus1
  • 1 Department of Gastroenterology, Evangelisches Krankenhaus Düsseldorf, Düsseldorf, Germany
Further Information

Publication History

Publication Date:
17 November 2006 (online)

The use of guide wires has become an important part of endoscopic retrograde cholangiopancreatography (ERCP) procedures. Their successful use depends mainly on their physical attributes and correct manipulation. They can be helpful, even indispensable, for selective cannulation, stricture access, and accessory exchange. Cannulation is usually performed by careful injection of contrast for visualizing the biliopancreatic anatomy and targeted guidance of the tip of a sphincterotome or an inserted guide wire. This approach should succeed in approximately 90 % of cases [1] [2] [3]. Alternatively, a guide wire can be gently passed in the direction of the targeted duct under endoscopic and fluoroscopic guidance without opacification. A recent randomized trial compared biliary cannulation with a guide wire through a sphincterotome with cannulation using a sphincterotome alone. The success rates were comparably high for both methods but the pancreatitis rate was significantly lower in the guide wire group [4]. All these procedures were performed by a single endoscopist, however, and the results should be confirmed in a multicenter trial.

In order to achieve smooth, wire-guided ductal access for getting past a difficult stricture, or for gaining access to a branch duct, guide wires with a flexible hydrophilic tip, with or without angulation, are preferable. The use of these wires can potentially increase success rates and reduce the risk of ductal injury. In contrast to the need for a slippery and soft tip for access, the shaft of a guide wire should be stiffer, in order to increase the trackability, which is important in that it allows the passage of accessories along the wire’s axis without kinking. A great number of devices with variations in these physical attributes have become available. “Hybrid” guide wires combine smart access and good trackability. Some types provide additional features, such as two different types of tips at both ends of the wire, or graduated markings on the shaft that aid positioning during exchange or stricture measuring. The complexity of these wires may explain their higher cost.

Most of the wires are available in lengths of 400 cm or more for traditional accessory exchange. Three different companies offer dedicated monorail-type systems with special devices which allow the use of guide wires with lengths of 260 cm or less. The main advantages of these systems are that the guide wire can be controlled by the nurse or the endoscopist and that it can be locked to reduce the risk of dislocation. The shorter length should reduce the risk of wire contamination and allows a smooth and quick exchange of accessories. However, these monorail-type systems are more expensive than traditional devices. One system also requires the use of a special duodenoscope (V-Scope; Olympus Corp., Tokyo, Japan) which provides a dedicated elevator that allows the guide wire to be locked.

Papachristou et al. [5] report on the exclusive use of a short hydrophilic guide wire for ERCP catheter and accessory exchange. In their large-volume center they prefer to use a 0.035-inch, 260-cm-long, completely hydrophilic “Glidewire” (Terumo Medical Corp., Somerset, New Jersey, USA) in about a fifth of procedures. When this short wire is used for traditional over-the-wire exchange of accessories the assistant advances all the available length of the wire into the catheter and then flushes it with water under pressure to keep it in position while the endoscopist is removing the catheter. This method of hydraulic ERCP catheter exchange is a well-known technique but had not been evaluated in a formal trial [6]. Papachristou et al. prospectively collected data for 100 patients (with no control group) who underwent ERCP that was initiated with the Glidewire. Although the authors emphasize that this wire is particularly useful for difficult cannulations or for the traversal of strictures, the selection criteria obviously depended strongly on the preference of the individual endoscopist - two of of the five ERCP endoscopists in their team routinely used the Glidewire except in cases when there was no need for a guide wire. This method of selection means that it was not just the difficult cases that were included, so that the need for a hydrophilic wire remains undetermined in the fifth of their enrolled patients who underwent ERCP for the treatment of choledocholithiasis.

Ductal access or stricture passage was achieved in all cases. These outstanding results reflect the high expertise of the group, particularly in view of the fact that 58 % of the patients had ductal strictures, many of which were caused by primary sclerosing cholangitis or cholangiocarcinoma, which are usually very difficult to manage. The skill of the team is further reflected by the two cases in which they even managed to gain simultaneous bilateral access to the intrahepatic ducts with two short Glidewires. Although no details were reported, similar results have obviously been achieved in the same institution with the guide wires that the other three endoscopists in the team preferred. These wires were used for 78 % of all ERCPs and it would appear from their overall wire usage rate of 1.1 wires per ERCP that an exchange was rarely required.

In total, 223 catheter exchanges were performed over the Glidewire. Wire loss occurred in 5 % of all exchanges; the mean exchange time was 26 seconds. These results are excellent but less experienced teams might find them difficult to reproduce. In contrast to wires with a nonhydrophilic coating of the shaft, the Glidewire could not be held by the V-Scope in a third of the 53 patients in whom this scope was used, so that a hydraulic exchange was required (as for procedures when a standard duodenoscope was used). Catheter exchanges with a V-Scope were shorter than exchanges with a standard scope by an average of 4 seconds. This small difference and the unreliable locking maneuver suggest that there is no advantage in using the V-Scope with a short Glidewire. Using a monorail-type system (Rx System; Boston Scientific Inc., Natick, Massachusetts, USA) for catheter exchanges was found to prolong the procedure by 5 seconds in comparison with standard devices. This may be explained by a more difficult separation of the floppy shaft of the Glidewire from the accessories and by the fact that it was not possible to perform a hydraulic exchange maneuver with these devices. This technique was nearly always successful when standard catheters were used.

Several additional steps have to be added to the procedure to minimize the risk of wire loss when using these hydrophilic wires: the Glidewire must be completely wetted with sterile water before each exchange; the catheter has to be flushed with water before insertion over the wire; and the authors also recommend flushing of the endoscope channel. “Floating the wire” to keep it in place when the endoscopist is removing the catheter requires the water to be injected at high pressure, which is not easy for the nurse or assistant. The black wire has no graduated markings on the shaft so it can be difficult to control its position without fluoroscopic control and without the facility to lock it securely in position. The procedure can become difficult if the wire is completely in the catheter and friction pressure exceeds the pressure for floating. This problem obviously did not occur in the Papachristou study, probably because of the team’s vast experience with the hydrophilic exchange maneuver. Endoscopists who have not had such experience have to manage this problem by inserting a second wire to push the impacted Glidewire or to cut the catheter to get hold of its distal end.

The authors did not report on the low trackability of the floppy Glidewire. This is surprising because a large proportion of their patients had difficult bile duct strictures, which usually demand guide wires with a stiff shaft to enable the operator to pass accessories such as balloons or stents in as straight a line as possible along their axis. Low trackability and a slippery shaft both also increase the risk of dislocation if the wire is not inserted very far into a duct, as in procedures involving pancreatic interventions. The “stiff” version of the Glidewire is less flexible than the “standard” device, but the authors did not mention the use of this version. The results of the study cannot therefore be extrapoloated to the stiff Glidewire, for which the hydrophilic exchange is also more difficult.

Papachristou et al. emphasize the excellent torquability of the short, angled-tip Glidewire [5]. However the advantage over other types of short guide wires with a hydrophilic tip is not obvious. Even a long wire should provide the same tactile responsiveness if a torque device is mounted on the shaft of the wire close to its entrance into the endoscope channel.

In summary, Papachristou et al. demonstrated that a skilful ERCP team can manage a large variety of endoscopic biliopancreatic interventions using a single short guide wire with a fully hydrophilic coating [5]. Standard catheters and accessories can be rapidly and reliably exchanged over the standard version of the Glidewire by the frequent use of the hydraulic technique. The compatibility of these wires with monorail-type systems is limited, however. Due to the lack of a control group, the study does not provide a comparison with other types of guide wires. The hydrophilic floppy tip of modern hybrid wires is similar to that of the Glidewire, but the shaft and the coating of the sheath is different. Because of their nitinol core material, they are also kink-resistant, but they have greater trackability and a higher surface friction of the shaft increases their ability to maintain tension without losing position. The hydraulic technique cannot be used for exchange of accessories over short hybrid wires. However, they can be used with different monorail-type systems or their combination, which allows for fast and secure instrumentation, and an exchange of a guide wire is rarely needed. Monorail technologies are more expensive than standard systems, although the total costs of a procedure depend on several factors, such as the duration of an operation, the number and type of accessories used, and the size and qualifications of the operating team. The endoscopist has to decide on the best mix of these factors. The highest preference should be given to clinical success and safety, even where there is a potential conflict with increasing pressure to economize. Depending on the individual patient and the expertise of the ERCP team, inexpensive and simple techniques can represent the best solution but more complex (and usually more expensive) modern technologies may offer new options for advanced operators and can improve the results of beginners. It is unlikely that a single guide wire or a single technique are optimal for all cases - an open-minded approach and appropriate evaluation of new devices and methods are required for further improvement of ERCP.

Competing interests: None

References

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H. Neuhaus, M. D.

Department of Internal Medicine

Evangelisches Krankenhaus Düsseldorf · Kirchfeldstrasse 40 · 40217 Düsseldorf · Germany

Fax: +49-211-919-3960 ·

Email: medizinischeklinik@evk-duesseldorf.de

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