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Inflation of an adequately sized balloon at low pressure (3–6 atmospheres) in a proximal branch can augment support by anchoring the guide catheter to the vessel and the branch (Figure 5.6) [9]. Low inflation pressures are essential to reduce the risk of dissection or damage to a small right ventricular branch or diagonal/marginal branch. In these branches, ischemia resulting from prolonged inflation is well tolerated. The technique is mostly used in treating CTO and is facilitated by a large guide catheter.

Another strategy that can be tried when a buddy wire does not resolve problems in tracking a stent to a target lesion because of tortuosity or calcification of the proximal segment, is to advance over the buddy wire a balloon optimally sized to match the diameter of the distal vessel (Figure 5.6). The balloon is positioned distal to the lesion and inflated at low pressure allowing enough space for the stent to be fully advanced across the target stenosis. It is imperative to remember that the distal anchoring balloon must be deflated and removed before the stent is deployed. In addition to providing extra support, the shaft of the distal balloon also acts as a rail to facilitate stent advancement. The operator needs to be experienced enough to anticipate when the force required may detach the stent from the balloon. Additional strategies can then be considered such as the need for better lesion preparation or the insertion of a subselectively engaged guiding catheter around the most tortuous segment, using the guide already in place or a 5 Fr in 6 or 7 Fr strategy as outlined in the next section (Figure 5.7).

Figure 5.7 Components of guidewire design.