Use of a distal protection device is essential in current percutaneous coronary intervention (PCI) procedures because distal embolization can be avoided with some specific lesions such as vein grafts,1,2 carotid stenoses3,4 and thrombus-rich coronary lesions.5,6 Several types of distal protection devices are available such as distal balloon occlusion, proximal occlusion and filter wire systems. The PercuSurge (PS) (Medtronic, Inc., Minneapolis, Minnesota) is a distal balloon occlusion system that occludes the distal artery during intervention and aspirates debris through a small-diameter aspirating catheter. The PS GuardWire™ offers advantages such as excellent passing ability due to a small-diameter profile. A disadvantage of the GuardWire, however, is its significant occlusion time which may cause myocardial ischemia. To protect the myocardium, the duration of ischemia of the standard PS system must be shortened, which involves a complicated procedure requiring quick and precise operation by the operator and assistant. Therefore, some operators often hesitate to use the PS system. The limited size of the inner lumen in the Export® aspiration catheter requires significant time to aspirate the thrombus and thus may worsen myocardial ischemia. To compensate for the disadvantages of the conventional PS method, we developed a new method for using the PS system with a 5 Fr guide catheter.
New method using the PS system with a 5 Fr GC. A 5 Fr Judkins-type guiding catheter was used with one of the following: Brite Tip® JL4LBT, Brite Tip JR3.5 LBT (Cordis Corp., Miami Lakes, Florida), Heartrail JL4, Heartrail JL3.5, Heartrail JR4, or Heartrail JR 3.5 (Terumo, Japan). The target lesion was dilated using a PCI balloon after the GuardWire protection balloon was inflated. The PCI balloon was deflated while the inflated protection balloon continued to intercept antegrade coronary blood flow. After the PCI balloon was removed, a deep-seated 5 Fr guiding catheter was passed through the target lesion and advanced into a position just proximal to the protection balloon. A 50 ml syringe was attached to a Y-connector. The debris and thrombus were aspirated from the coronary artery using the 5 Fr guiding catheter. After the aspiration, the guiding catheter was pulled back to the coronary ostium and then the GuardWire protection balloon was deflated. For implantation of a stent, the same method was repeated. A diagram of the new method is presented in Figure 1. Representative individual cases are shown in Figures 2 and 3.
Patients. This was a retrospective, nonrandomized trial involving 14 acute myocardial infarction (AMI) patients admitted to Hirosaki University Hospital. The method of treatment was at the discretion of the investigator. The control group was comprised of 18 patients who fulfilled the inclusion criteria and were treated with the conventional PS method before starting the new method with a 5 Fr GC. All patients exhibited onset of AMI less than 24 hours before enrollment and gave written, informed consent before emergency catheterization. Patients were excluded if deep engagement of a guiding catheter appeared to be anatomically impossible. All patients were treated with primary PCI. No subjects received intravenous thrombolysis before transfer to our hospital.
Coronary angioplasty procedure. In this new method of use of the PS system, arterial access was created using a 5 Fr introducer sheath, whereas in the conventional method, arterial access was created using a 7 Fr introducer sheath. After the arterial puncture, 10,000 units of heparin were administered to all patients. No thrombolytic agents were administered before or after PCI. Glycoprotein IIb/IIIa antagonists were not administered to any of the patients because they are not approved for clinical use in Japan. The new PS method was performed if the angiographic results indicated that it was appropriate for treatment of the lesion. The distal protection balloon was inserted alone if possible, but when there was difficulty, it was inserted after the conventional 0.014 inch guidewire. After predilatation, stent implantation was performed at a pressure > 12 atm. One of the following stents was chosen at the discretion of the operator: Multi-Link Plus™ (Guidant Corp., Santa Clara, California), Multi-Link Penta™, Duraflex™ (Avantec Vascular Corp., Sunnyvale, California), BeStent™ 2, S670 (Medtronic, Inc., Minneapolis, Minnesota), Taxus® Express2™ (Boston Scientific Corp., Natick, Massachusetts) or NIR® (Boston Scientific). The PCI procedure was considered successful if the stent was deployed and TIMI 2–3 flow was achieved on final angiography. Daily oral administration of 3 200 mg of aspirin and 200 mg of ticlopidine were started as soon as possible after stent implantation and continued for more than 4 weeks. If the patient underwent PCI via the transradial approach, the arterial sheath was removed immediately after PCI in the catheterization laboratory. If the patient underwent PCI via the transfemoral approach, the sheath was removed 3–4 hours after PCI outside the laboratory. No femoral hemostasis devices were used because their cost is not reimbursed by the socialized health insurance system of Japan for patients who stay in the hospital for more than 2 days after a transfemoral coronary intervention. The procedure time was defined as the time from the arrival of the patients in the catheterization laboratory to their exit from the laboratory, and thus included the time required for diagnostic angiography, PCI, left ventricular angiography and pressure measurements using a thermo-dilution catheter.
The baseline characteristics of the patients, their lesions, and the final results are listed in Tables 1 and 2. Aspiration was successful in all patients in both groups. Final TIMI 3 flow was achieved in 86.7% of patients with the new method and in 88.9% of patients with the conventional method. Stent deployment was successful in all cases of both procedures without the use of a buddy wire.
With the new PS system method using a 5 Fr GC, significant reductions were realized in distal protection time, fluoroscopy time, total procedure time and total amount of dye used compared with the standard PS procedures (Figures 4 and 5).
No coronary dissections were caused by the protection balloon or the deep-seated guiding catheter. The PCI procedure was successful for all patients in this study. There was no significant difference in maximum CPK, ejection fraction and end-diastolic volume index by left ventriculography 2 weeks after the PCI (Table 3).
The complication rates are listed in Table 4. The only major complication was low-output syndrome in 1 patient who underwent the standard PS procedure and died from this complication.
We report here a new method of use of the PS with a 5 Fr GC. This method reduced procedure time, distal occlusion time, fluoroscopy time and volume of contrast media required. The PS system provides good distal protection due to the balloon’s ability to provide complete occlusion and offers better trackability than filter protection devices. However, the following problems are associated with the PS system: low manipulability and operability of the GuardWire; damage caused to peripheral vessels by the protection balloon; need for a large guiding catheter (≥ 7 Fr) to be used as an export aspiration catheter; inability to collect large thrombi due to the narrow catheter lumen; low aspiration power of the Export catheter; complexity of the PS procedure; steep learning curve; and long ischemic times.
By using a 5 Fr guiding catheter for aspiration, we demonstrated that this approach resolved some of the problems associated with the conventional PS procedure. Since we have eliminated the need to exchange a balloon for an aspiration catheter, the ischemic time was shortened and the procedural techniques were simplified. Furthermore, removal of debris and thrombi was better facilitated because the cross-sectional area of the 5 Fr GC is twice that of an aspiration catheter. This new method does not require an aspiration catheter, which costs about $800 (U.S.) in Japan, and thus offers a considerable financial advantage.
PCI via the radial approach can alleviate postoperative restraint, even in cases of AMI, and it is associated with a lower incidence of hemorrhagic complications. Thus, it has been reported that PCI via the radial approach contributed to earlier patient discharge.7 However, radial artery occlusion is a limitation of this approach since the ratio of radial artery diameter to sheath diameter is an important factor in predicting radial artery occlusion.8 Using a small 5 Fr sheath avoids radial artery occlusion and is therefore another advantage of this new method.
Some physicians have expressed concern that PCI with a 5 Fr guiding catheter might reduce success rates due to its weak backup power. The physics of guiding catheters have demonstrated that backup force is determined by guiding catheter size, the angle between the guiding catheter and the aorta, and the friction between the guiding catheter and the aorta.9 However, our experience and a review of the literature show that these limitations could be overcome. In fact, some studies have found that the success rate for PCI was similar or even higher with a 5 Fr catheter than with a 6 Fr catheter.10
There are some limitations to this new method. It cannot be applied when deep engagement of a guiding catheter is anatomically difficult because of sharp bending or tortuosity in the coronary artery or a severe stenosis proximal to the culprit lesion or thrombus. Actually, we did not perform this method in the circumflex artery during this study because of the typically wide angles of the left main trunk and circumflex artery. It may however be feasible in circumflex arteries if the anatomical angle is suitable.
Recent studies have shown that the efficacy of distal protection in patients with AMI is questionable.11 This study targets acute coronary syndrome target patients because it was designed and performed before the publication of the EMERALD study. However, this new method can be applied to PCI in vein grafts, where the safety and feasibility of distal protection have already been established. Furthermore, vein grafts are an easier target for this new method since they are straighter and less tortuous than native coronary arteries.
In conclusion, this new method of use for the PS system utilizes the advantages of a slender and flexible 5 Fr guiding catheter as an aspiration catheter and increases the versatility of this system.
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