An important step in complex percutaneous coronary interventions frequently involves the successful wiring of a side branch or bifurcation. Although this is usually performed without difficulty, some anatomical subsets present technical challenges. Among the most difficult subtypes are branch vessels that arise at a retroflexed steep angle from the main vessel and branch vessels that arise from a stented segment. This article reviews some of the tips and tricks that can be used to wire difficult side branches.

TECHNIQUE 1: REVERSE HOOK
Figure 1A is an example of an extreme reverse angulation origin of a right ventricular branch vessel from the mid-right coronary artery. Initial attempts to directly wire this branch vessel with floppy-tipped and hydrophilic wires (to protect it during stenting of the main right coronary artery) were unsuccessful. We then moved on to the reverse hook technique. In this technique, we advanced a hydrophilic guidewire (PT Graphix Intermediate, Boston Scientific Corporation, Natick, MA) into the main vessel distal to the origin of the target branch vessel. A J loop is made at the tip of the wire by catching onto another side branch (Figure 1B). The tip of the J is then pointed toward the branch vessel, and the wire is carefully pulled back, analogous to a Simmons catheter. The tip of the J catches and hooks the origin of the side branch, and when the wire is pulled farther back, it migrates farther into the side branch (Figure 1C and D). Once a sufficient length of wire is in the side branch, the rest of the wire can be carefully advanced antegrade.

Care must be taken when making a J hook at the tip of the wire (which is done by catching and pushing against side branches or tortuous segments of the artery), because this may result in vessel injury. Also, as the J tip unhooks and prolapses into the side branch, it may spring forward and potentially injure the branch vessel. This technique may not work well in large main vessels because it would be difficult to form and maintain the hook.

TECHNIQUE 2: BALLOON BACKSTOP
When there is significant vessel angulation at the origin of the side branch that is associated with a large parent vessel diameter, it may be difficult to engage a wire into the branch vessel. Figure 2A is an example in which a calcified circumflex artery arises with an acute retroflexed angulation from the left main coronary artery. In this patient, whose left anterior descending artery (LAD) is protected by an internal mammary graft, there is also severe ostial left main artery stenosis (Figure 2B). The angulation of the circumflex artery and the size of the left main artery predispose the guidewire to prolapse into the LAD rather than advance into the circumflex. In such situations, balloon occlusion at low pressure in the parent vessel just distal to the origin of the side branch may serve as a backstop, preferentially deflecting the wire into the side branch (Figure 2C through F). In this technique, the main vessel is wired first. A compliant balloon is then inflated at low pressures (such as 2 atm) to avoid injury in the ongoing vessel (the LAD in this case) just distal to origin of the side branch. Another wire is advanced into the side branch, with the balloon preventing prolapse of this wire and deflecting it into the side branch.

Caution should be exercised throughout this technique because balloon occlusion of any artery may result in distal ischemia. Therefore, this technique must be used judiciously and quickly. If the procedure takes too long, intermittent deflation of the balloon to allow for reperfusion is recommended. Furthermore, there may be potential injury to the main branch vessel from balloon inflation. This can be avoided by using low-pressure inflations and compliant balloons.

TECHNIQUE 3: TWIN-PASS CATHETER
The Twin-Pass catheter is a dual-lumen specialty catheter (Figure 3).1 It has a .014-inch rapid-exchange lumen and an over-the-wire lumen. There are two different sizes available, with respect to the over-the-wire lumen, including a .014- or .018-inch wire, respectively. The distance between the distal rapid exchange tip and the more proximal over-the-wire aperture is 1 and 2 cm, respectively. The catheter can be placed in the main vessel, and the side lumen is used to preferentially deliver another wire into the side branch. However, because the side lumen does not reliably control the orientation of the wire, this technique may be of limited value in extreme angulations or severe side branch ostial stenoses.

TECHNIQUE 4: VENTURE CATHETER
The Venture Wire Control catheter (St. Jude Medical, Inc., St. Paul, MN) is a .014-inch, wire-compatible, deflectable catheter (Figure 4).2,3 The tip of the catheter can be oriented and deflected up to 90° by turning a knob on the proximal handle of the device. This allows the operator to aim the catheter tip directly into a side branch and advance the guidewire. Additionally, there is improved pushability and support with this catheter. However, the successful use of this device requires some experience because the tip may deflect in an unpredictable direction. Furthermore, it cannot be easily used in small vessels because the catheter and the deflected tip may be too large for the vessel lumen; with this technique, there is a theoretical risk of vessel injury with the deflection of the tip.

TECHNIQUE 5: STEER-IT DEFLECTING TIP GUIDEWIRE
The Steer-IT Deflecting Tip guidewire (Cordis Corporation, Warren, NJ) is a .014-inch guidewire with a flexible radiopaque platinum alloy coil on the distal tip. The distal tip is deflectable bidirectionally using the proximal handle mechanism of the guidewire. The wire can be used in the coronary and peripheral vasculature and comes in two tip lengths of 3 and 7 mm. Similar to the Venture catheter, the Steer-IT Deflecting Tip guidewire can be guided into a severely angulated side branch. Although it may be possible to engage a side branch using this specialized wire, it may be more difficult to advance than a dedicated hydrophilic wire. The deflectable tip may also predispose to vessel injury if the wire is deflected or advanced in the wrong direction or into the vessel wall.

CONCLUSION
Side branch access can be technically challenging in extreme angulations or when there is severe side branch ostial disease. Knowledge concerning special techniques, such as those described in this article, may be useful in the appropriate anatomical and clinical setting.

Khung Keong Yeo, MBBS, is from the Division of Cardiovascular Medicine, University of California, Davis Medical Center, in Sacramento, California. He has disclosed that he holds no financial interest in any product or manufacturer mentioned herein. Dr. Yeo may be reached at (916) 734-3764; khung.yeo@ucdmc.ucdavis.edu.

Jason H. Rogers, MD, is from the Division of Cardiovascular Medicine, University of California, Davis Medical Center, in Sacramento, California. He has disclosed that he holds no financial interest in any product or manufacturer mentioned herein. Dr. Rogers may be reached at (916) 734-3764; jason.rogers@ucdmc.ucdavis.edu.

  1. Arif I, Callihan R, Helmy T. Novel use of twin-pass catheter in successful recanalization of a chronic coronary total occlusion. J Invasive Cardiol. 2008;20:309-311.
  2. Aranzulla TC, Sangiorgi GM, Bartorelli A, et al. Use of the Venture wire control catheter to access complex coronary lesions: how to turn procedural failure into success. Eur Interv. 2008;4:277-284.
  3. McClure SJ, Wahr DW, Webb JG. Venture wire control catheter. Cathet Cardiovasc Interv. 2005;66:346-350.