Cath Lab Digest

ABSTRACT: The failure to deliver a stent across the target lesion during percutaneous coronary intervention, especially in arteries with calcified tortuous anatomy, is often due to insufficient back-up support from the guiding catheter. Deep-vessel intubation with the guiding catheter may overcome this problem, but risks coronary dissection. The Heartrail II (Terumo, Japan) “five–in-six catheter system” (or “mother-and-child” catheter) comprises a flexible-tipped long 5 Fr catheter advanced through a standard 6 Fr guiding catheter to deeply intubate the target vessel, thus providing enough back-up support to enable stent delivery. Here we describe a newly developed “child” support catheter (The GuideLiner; Vascular Solutions, Inc., Minneapolis, Minnesota), report its successful use in a series of 4 difficult cases, and discuss practical tips to optimize its performance.

The failure to deliver a stent across the target lesion during percutaneous coronary intervention (PCI), especially in arteries with calcified tortuous anatomy, is often due to insufficient backup support from the guiding catheter. Commonly used methods to overcome this problem include vessel straightening with a second “buddy” wire^1,2 or “buddy” balloon,³ the use of an anchor balloon⁴ and the use of guiding catheters of larger caliber and more supportive shape. Deep-vessel intubation with the guiding catheter may also help, but risks coronary dissection. The Heartrail II (Terumo, Japan) “five-in-six catheter system” (or “mother-and-child” catheter) comprises a flexible-tipped, long (120 cm) 5 French (Fr) catheter advanced through a standard 6 Fr guiding catheter to deeply intubate the target vessel.^5-7 This system uses the target vessel itself to provide the extra backup support required for stent delivery. Furthermore, the absence of a primary curve and the flexibility of its tip permit the “child” catheter to remain coaxial with the target vessel, thereby minimizing the risk of catheter-induced coronary dissection. Here we describe a newly developed “child” support catheter⁸ (GuideLiner; Vascular Solutions, Inc., Minneapolis, Minn.), report its successful use in a series of 4 difficult cases, and discuss practical tips to optimize its performance.

Device and Technical Detail

The GuideLiner catheter is a coaxial guiding catheter extension delivered through a standard guiding catheter on a monorail. It is comprised of a flexible yellow 20-cm straight extension (internal diameter approximately one French size smaller than the guiding catheter) connected to a stainless-steel push tube, with a “collar” that can be deployed through the existing Y-adapter for rapid exchange delivery (Figure 1). It neither lengthens the guiding catheter nor requires a second hemostatic valve. The extension comprises an inner polytetrafluoroethylene (PTFE: Teflon) lining, surrounded by a stainless-steel coil (imparts flexibility and strength) and an outer layer of Pebax^® polymer. Its silicon coating imparts lubricity.

Passage of the Guideliner through the guiding catheter is designed to be tight in order to prevent slippage. Delivery of the extension into the target vessel is aided by a radiopaque marker located 0.105" (2.66 mm) from the tip and white positioning markers on the push tube at 95 cm (single) and 105 cm (double) (Figure 2). The GuideLiner is currently available in three sizes: 5-in-6 Fr (internal diameter 0.056"), 6-in-7 Fr (0.062") and 7-in-8 Fr (0.071").

The GuideLiner catheter permits very deep intubation of the target vessel, thus providing backup support to facilitate stent delivery across heavily calcified lesions in tortuous vessels. The deeply-engaged extension is always aligned coaxial to the target vessel, and this is particularly useful if the takeoff of the coronary ostium prevents coaxial engagement of the guiding catheter. Furthermore, it enables the injection of radiocontrast close to the target lesion, improving its visualization. The manufacturer does not recommend its use in target vessels of < 2.5 mm diameter, in saphenous vein grafts, or in carotid artery intervention.

Case 1. Percutaneous intervention of a tortuous calcified mid right coronary artery (RCA). A 74-year-old patient who had previously undergone coronary artery bypass grafting was admitted with an inferolateral non-ST-elevation myocardial infarction (NSTEMI). His angiogram showed a moderate proximal stenosis of the left anterior descending artery (LAD) and a severe proximal stenosis of the small circumflex. The graft to the LAD was occluded, but there was a patent graft which back-filled the right posterior descending artery up to the crux. The RCA was tortuous and calcified, with severe stenoses of the proximal and mid vessel (Figure 3a), rendering the posterolateral territory a substrate for ischemia.