Читать книгу Interventional Cardiology - Группа авторов - Страница 136

In the GuideLiner® catheter (Teleflex‐Vascular Solutions, Maple Grove, MN, USA) a coaxial short distal soft catheter is mounted at the tip of a long stainless‐steel rod, which extends outside the guide catheter. This enables deep intubation of the coronary artery to achieve extra support and improve coaxial alignment. It has a coaxial 20 cm long catheter with a radiopaque marker situated 2.7 mm from the tip from the tip, joined to a 125 cm compact metal hypotube by means of a ring (“collar”, made of metal in the first version and replaced by a lubricious polymer in the V2 version), which can be deployed through the existing Y‐adapter for rapid exchange delivery. The device is available in three sizes: 5‐in‐6 (0.056 inch internal diameter (ID)), 6‐in‐7 (0.062 inch ID), and 7‐in‐8 (0.071 inch ID). Its monorail design permits rapid exchange and offers important advantages over its predecessors, the “five‐in‐six mother and child” catheters Heartrail II®, which had a coaxial system that made their utilization more demanding [11]. Furthermore, rapid exchange helps with deployment through the existing hemostatic valve without extending the guiding catheter length, and so does not limit the useable length of balloons and wires. Other Companies designed similar catheters such as the Guidezilla™ (Boston Scientific, Marlbourough, MA, USA), Telescope (Medtronic, Minneapolis, MN, USA), Gideon (IVS, Maastricht, The Netherlands), claiming more lubricious coatings or smoother connections between hypotube and distal catheter. The Guidezilla is probably the most widely used guide extension after the GuideLiner, is mounted on a monorail system, which extends the guide catheter and enables deep intubation of the coronary artery. It is made of a distal end of 25 cm covered by a hydrophilic polymer, joined to a 120‐cm compact metal hypotube. The distal flexible extension consists of a pair of radiopaque markers, the first situated 2 mm from the tip and the second 3 mm from the transition collar. The device is available in one size 5‐in‐6 and compatible with guide catheter ≥6 Fr. An additional system, with sizes compatible also with 5 Fr guiding catheters, is the Guidion rapid exchange guide extension catheter (IMVS, Roden, the Netherlands).

De Man et al. [14], published results from the Twente GuideLiner Registry identifying three primary indications for the use of the device: improvement of back‐up and facilitated stent delivery (59%), more selective contrast injection (13%), and improvement of alignment of the guide (29%). Moreover, they found a device and procedural success rate of 93% and 91%, respectively, without major complications and a small incidence of minor complications (3%). The safety and efficacy of utilizing the GuideLiner monorail catheter to treat complex lesions was confirmed in recent experience published by Chan et al and Fabris et al. [15,16], showing good performance of the device in the settings of bypass graft intervention, bifurcation lesions, and chronic total occlusions. In order to avoid damage of the proximal vessel, especially in case of non‐coaxial alignment of the coronary ostium and extreme proximal vessel tortuosity (e.g. a shepherd’s crook’s origin of the RCA”), a balloon advanced distally can be used to reduce the chance of damaging the ostium and the proximal vessel by acting as centering rail). If the guide extension does not advance this can be caused by vessel tortuosity and poor GC back‐up and solved inflating the distal balloon to gently attract it or can be caused by presence of proximal stenoses or calcifications, in need of effective predilatation.