with 0.014” coronary guide wires and 6 F guiding catheters. The most distinctive feature of the Glider balloon is the presence of an oblique cut of the distal tip, which can be rotated from the proximal hub because of its unique braided reinforced and lubricious shaft. The balloon diameters currently available are 2.5 and 3.0 mm, the length is 4.0 mm with a single mid marker and a rated burst pressure of 16 Atm with low compliance. This short balloon is specifically designed for optimal side branch ostium expansion without damaging the distal side branch, and thus, minimizing the risk of side branch dissection [19].
A list of the most commonly used ultra low profile PTCA balloon is reported in Table 5.6.
Table 5.6 List of commonly used ultra low profile PTCA balloon.
| Lesion Crossing profile(“) /balloon diameter (mm) | |
|---|---|
| Nic Nano Hydro CTO Balloon, SIS medical, Swiss | 0.0195” / 0.85mm |
| Tazuna, Terumo, Tokyo, Japan | Not reported / 1.25mm |
| Ikazuchi (Kaneka, Osaka, Japan | 0.0157” / 1mm |
| Sapphire II Pro CTO, Orbus Neich, Hong Kong | 0.016” / 1mm |
Cutting balloon and scoring balloon catheters represent two different strategies developed in the context of resistant lesion preparation, enabling to prepare the coronary plaque and to create cracks in the calcium or dense fibrotic wall before stenting.
The cutting balloon has been available for almost 30 years. It is a semi‐compliant balloon with three thin sharp blades mounted on its body, designed to cut the continuity of fibrocalcific plaque once the pressure of the balloon forces them against the vessel wall, creating fissures on the plaque. The Flextome cutting balloon (Boston Scientific, Malborough, MA, USA), has three blades equally spaced around its circumference which come into contact with the arterial wall and score the vessel wall. The balloon is specifically indicated for discrete lesions with resistance to conventional balloon angioplasty without heavy calcification. Despite its theoretical advantages, in the Cutting Balloon Global Randomized Trial the primary endpoint of six‐month binary restenosis did not differ between CBA and POBA (31% vs. 30%, p=0.75) and the rate of perforation was higher with CBA (0.8% vs. 0%, p=0.03) [20]. These negative results, together with the difficulties associated with cutting balloon delivery due to its high crossing profile (0.041‐0.046”), led to the development of the newer generation of cutting balloon Wolverine™ Cutting Balloon (Boston Scientific, USA). In the Wolverine CBA, the atherotome’s support thickness has been reduced, becoming compatible with 6 Fr catheters for all diameters, without affecting the functional height of the blade, resulting in an overall smaller crossing profile and improved crossability.
Scoring balloons, also known as “focal force balloons”, are semicompliant balloons encircled by scoring elements. These scoring elements allow focal concentration of the force during inflation and decrease balloon slippage. Scoring balloons have similar indications to cutting balloons, but scoring balloons are more flexible, have a better profile and can achieve a full expansion with a low inflation pressure, with consequently less trauma to vessel walls and a minor risk of coronary dissections [21,22]. Several types of scoring balloons are now available for treatment of mild to moderate calcified lesions. The AngioSculpt (Spectranetics‐Philips) is a semicompliant balloon with three spiral rectangular Nitinol scoring elements, also available in a drug‐coated version (AngioSculpt X, Spectranetics‐Philips). Developed for both coronary and peripheral vascular applications, the Angiosculpt is similarly used in highly resistant lesions when conventional balloons are unable to dilate the vessel. In a feasibility trial, the AngioSculpt balloon was used for the treatment of de novo lesions prior to BMS implantation and showed very high procedural success and a target lesion revascularization rate of 10% at 6 months [23]. These results were confirmed in an observational study, in which 37 patients treated with AngioSculpt before stent implantation were compared to 145 patients treated with direct stenting and 117 patients with traditional plain old balloon angioplasty before stent implantation. IVUS assessment showed greater stent expansion in the AngioSculpt group than in the other two groups (89% versus 74% of vessels with an area >5.0 mm2, respectively) [24].
Another focal force balloon is the Chocolate balloon (TriReme Medical, Pleasanton, CA, USA), which is a traditional semi‐compliant balloon within a nitinol cage. When the balloon is inflated, the cage restrains the balloon expansion, and the balloon protrudes from between the struts of the nitinol cage applying focal pressure to discrete areas of the plaque. Theoretically, this will result in more controlled plaque fracture. The NSE Alpha scoring balloon (B Braun, Berlin, Germany) has three triangular flexible nylon elements on the balloon surface attached only at the proximal and distal edges of the balloon. Promising results for predilatation of severe calcified lesions were shown with the leopard‐crawl technique [25]. The Scoreflex (Orbus Neich) is a semicompliant balloon with two fixed Nitinol wires on opposite sides of the balloon surface [26]. Otsuka et al. reported a case series where prolonged inflation of the Scoreflex balloon allowed adequate dilation of severe calcified plaques as shown by the ‘creep phenomenon’, whereby prolonged inflation of the balloon produces a distortion force capable of expanding a resistant calcified lesion [27]. Scoring balloons have been considered by cardiologists as an alternative to cutting balloons and, in recent years, have been preferred because of major flexibility and deliverability, although no specific randomized control trials are reported in the literature.
Non‐compliant balloon catheters
Non‐compliant (NC) balloons, unlike semi‐compliant balloons, tolerate high inflation pressures, exhibiting a small increase in diameter. NC balloons allow more uniform balloon expansion and the application of higher forces in a focal segment of a coronary vessel, avoiding dog‐bone deformation exerting excessive pressure at the edges and potentially causing coronary dissections or perforations. When facing a mild to moderate calcific coronary lesion, repeated and prolonged inflations with NC balloons should be encouraged as the first choice, especially when the calcium arc is restricted (<90°).
Sapphire II (OrbusNeich, Hoevelaken, Netherland), a last generation NC balloon, is a well‐balanced balloon catheter that crosses lesions without boundaries. This catheter offers an ultra‐low crossing profile across a broad range of configurations, including 1.0 mm diameter balloons and 150 cm shaft working length versions. Sapphire II features a flexible, supple balloon material for slender rewrap; an XD (eXtra Durable) shaft for enhanced pushability and superb kink resistance; proprietary Hydro‐X coating for lubricious crossing; and Z‐Tip technology resulting in ‘Zero’ transition between the tip and guidewire for smooth and safe penetration of the tightest of lesions.
The OPN NC balloon (SIS Medical) is a double‐layered balloon that allows high‐pressure dilatation. This balloon catheter uses twin‐layer technology to allow super high pressures within the balloon with minimal increases in diameter. This balloon can be inflated with a nominal pressure of 10 atm and a rated burst pressure of 35 atm, but the balloon was tested up to a pressure of 45 atm and many operators report very rare balloon ruptures at pressures as high as 5573 kPa 55 atm, the maximal level allowed by the special indeflator provided with the balloon. The OPN NC balloon is available in diameters ranging from 1.5 to 4.5 mm (in 0.5 mm increments) and lengths of 10, 15, and 20 mm. The OPN NC balloon is a dedicated device for the treatment of in‐stent restenosis, heavily calcified lesions or other lesions that cannot be dilated. The OPN balloon is compatible with 0.014 inch wires and 5 Fr access, but it has a high profile (0.028 inches), although this is better than scoring and cutting balloons, and so it is difficult to recross or reuse after inflation. In a retrospective study evaluating 326 undilatable lesions in which conventional NC‐balloons failed to achieve adequate post‐dilatation luminal gain, the OPN NC balloon successfully treated >90% of undilatable lesions compared with