Management of Distal Coronary Perforations

Coronary artery perforation (CAP) is an uncommon, yet potentially devastating, complication of percutaneous coronary interventions (PCI).¹ Early reports of this catastrophic complication date back to the early 1980s.² In a recent review of 6,245 patients undergoing coronary intervention, the incidence of CAP was 0.77%.³ Coronary perforations appear to be increasing in frequency. The aggressive use of glycoprotein IIb/IIIa inhibitors and pretreatment of patients with clopidogrel and ticlopidine have rendered it difficult for previously benign distal guidewire-related microperforations to seal themselves. The increased use of hydrophilic guidewires whose distal tips are difficult to control have also led to an increased incidence of guidewire-related perforations.
Another mechanism of coronary perforation results from rupture of the coronary artery. These are usually large perforations associated with hemodynamic collapse and occur in proximal coronary segments. These perforations carry a high mortality risk and their management revolves around prompt restoration of hemodynamics and definitive treatment with a polytetrafluoroethylene (PTFE)-covered stent. The incidence of perforations is higher in the elderly, women, patients in whom aggressive balloon sizing is used and with the adjunctive use of atheroablative devices.^4–6
Management modalities for CAP have evolved from surgical to less invasive percutaneous techniques. Reported treatment modalities have included open surgical repair, covered stent/grafts, transcatheter injection of polyvinyl alcohol, autologous blood seal, gel foam embolization, transcatheter subcutaneous tissue delivery and coil embolization.^7–10 All reported treatment strategies are preceded by reversal of anticoagulation and balloon inflation at the site of the perforation or just proximal to the perforation to prevent continued extravasation and tamponade.
This case report describes the nonsurgical management of a distal left anterior descending artery (LAD) perforation and is accompanied by a brief review of the different techniques available for sealing off a persistent leak in a perforated distal vessel. This case is clinically relevant because most interventional cardiologists are experienced with using covered stents when confronted with perforations. These are life-saving devices for proximal perforations and in large vessels where they can be safely delivered, but are of little to no value in distal perforations and in small vessels. Most cardiac catheterization laboratories are not equipped with the different coils, embolic glues and delivery catheters necessary to manage distal perforations. This case report attempts to familiarize the cardiac interventionalist with the different options available in managing this increasingly frequent emergency.

Case Report. An 80-year-old diabetic female underwent elective left-heart catheterization for refractory angina and abnormal myocardial perfusion imaging 6 months following PCI of the distal LAD. Angiography revealed flow-limiting in-stent restenosis of the distal LAD (Figure 1). After 2 drug-eluting stents were deployed in the distal LAD, a Type III coronary perforation was noted in the distal LAD with brisk extravasation of contrast media into the pericardial sac (Figure 2). Anticoagulation with bivalirudin was stopped and a 2.5 mm Maverick balloon (Boston Scientific Corp., Natick, Massachusetts) was inflated to 12 atm just proximal to the site of perforation.
Pericardiocentesis was performed to relieve cardiac tamponade, and 200 cc of fresh blood was drained from the pericardial space. A pigtail catheter was left in place in the pericardium. The balloon was then deflated and repeat angiography showed persistent extravasation of contrast media. At this point, the options were referral for open repair of the distal vessel without any option of revascularization distal to the perforation, continued balloon inflation, or embolization. It was felt that loss of the apical LAD territory would be reasonably well tolerated in a patient with normal left ventricular function, thus the option of embolizing the distal vessel was pursued.

A 3 Fr Renegade^® STC 18 microcatheter (Boston Scientific) was advanced to the distal LAD and coil embolization was performed with deployment of 2 overlapping VortX®Diamond Interlock fibered coils (2/3 mm x 2.3 cm and 2/4 mm x 4.1 cm, Boston Scientific). A post-coil LAD arteriogram demonstrated good angiographic result with total occlusion of the distal LAD and no further extravasation (Figure 3). A postprocedure echocardiogram on the following day revealed an ejection fraction of 60% with preserved apical wall motion and trivial pericardial effusion. The peak infarct size, as measured by serum biomarkers, was a troponin of 0.13 μg/L and a creatine phosphokinase of 67 mg/dL. The patient had an uneventful course in the coronary care unit and was discharged home 3 days later in stable condition. At 3-month follow up, she remains stable with no clinical signs of angina or heart failure.

Discussion. Coronary perforation with cardiac tamponade is a bonafide cardiovascular emergency. The mortality rate associated with this condition approaches 10%, even when appropriate treatment is administered.¹¹
Ellis et al described a classification system as a predictor of outcomes. Perforations are classified based on their angiographic appearance: Type I, extraluminal crater without extravasation; Type II, pericardial/myocardial blushing; Type III, perforation 1 mm diameter with contrast streaming; and Type III CS, perforation 1 mm with “cavity spilling”.⁶ Type III perforations are associated with the rapid development of cardiac tamponade (63%), the need for urgent bypass surgery (63%) and a high mortality rate (19%).
The first and foremost principle in managing coronary perforations is attention to hemodynamics. Establishing a large-bore central intravenous access (for fluids and inotropes), along with prompt airway management is crucial to establish before the patient leaves the catheterization laboratory. Reversal of anticoagulation is the next step in the management of these patients.
It is also prudent to promptly inform the cardiothoracic surgical department about the patient so that concurrent preparation of an operating room (OR) suite can be done. The availability of additional nursing and circulatory assistance in the catheterization laboratory allows for the smooth execution of critical aspects of the procedure. The next step involves evacuation of the pericardial effusion and relief of tamponade physiology. This can be done using fluoroscopy if there is no time to obtain echocardiographic guidance, but the latter is preferable to prevent inadvertent right ventricular puncture in an anticoagulated patient.
Once the “ABCs” have been attended to, the next step involves maintaining guidewire access to the distal vessel. If this is lost, then percutaneous management is not feasible and the patient needs to be expeditiously transferred to the OR for open repair of the perforated artery.
In the event of CAP, initial conservative treatment strategies should include immediate and prolonged balloon inflation at the site of vessel injury. A perfusion balloon may be utilized during prolonged balloon inflations, but has fallen out of favor because of the availability of premounted covered stents for the treatment of proximal perforations. Covered stents are an effective means of managing CAP, especially when the perforation is in the proximal or mid-vessel where delivery of these devices is relatively straightforward. This case and review focuses on the more frequently-occurring distal perforations where the delivery of a covered stent is not feasible and potentially harmful.
Many different approaches to this problem have been described in the literature. These have included injection of polyvinyl alcohol, autologous blood seal, gel foam embolization, transcatheter subcutaneous tissue delivery and coil embolization.7–10 Of these different options, the most common approaches involve the use of coils and gel foam.
Coils. Metallic coils are permanent embolic agents that can be deployed through standard angiographic catheters or 3 Fr microcatheters. Coils offer the advantages of precise placement into very distal locations. These agents are constructed of stainless steel or platinum alloys with synthetic wool or dacron fibers attached along the length of the wire to increase thrombogenicity. Stainless steel coils are compatible with polyethylene and braided nylon catheters, but should not be deployed through polyurethane catheters, as coils may become trapped in the distal catheter tip. The choice of coil size is important for preventing incorrect placement. The coil size should be slightly larger than the target vessel diameter to allow for proper adherence to the vessel wall. A small coil may migrate downstream, while too large a coil may displace the delivery catheter from the target vessel and protrude into a feeding branch.¹²
The Interlock Fibered IDC Occlusion System ($410.00; Boston Scientific) is a modified interlocking detachable coil indicated for use in the peripheral vasculature and is available in a variety of coil lengths, diameters and shapes.¹³ The system is equipped with Helical 2D Coils featuring a small distal diameter and designed to facilitate deployment. VortX^® Diamond fibered platinum coils ($385–$510.00/box of 5) with a doubleapex shape and dual small ends are designed for vessel occlusion, and are deployed with the accompanying 3 Fr Renegade fiber-braided microcatheter ($399.00; Boston Scientific). This combination of coil and catheter was used in the case described here and worked effectively.
Also available for use in larger vessels (vein grafts) and in the peripheral vascular system are the 0.018 inch and 0.035 inch fibered platinum coils ($285–$425.00; Boston Scientific). The coils come loaded in an introducer for ease of transfer into the catheter. A coil plunger is used to push the coil out of the introducer and into the catheter.
Matrix2 detachable coils and GDC 360^° coils (Boston Scientific) are intended for embolization of inoperable intracranial aneurysms, arteriovenous malformations (AVMs) and arteriovenous fistulae.¹³ They can also be used for arterial and venous embolizations in the peripheral vasculature. Matrix2 coils employ a well-characterized polyglycolic-polylactic acid (PGLA) biopolymer that has been used in many biocompatible devices such as surgical staples, orthopedic implants, sutures and drug-delivery vehicles. Glycolic and lactic acids, the byproducts of PGLA hydrolysis, promote fibrocellular proliferation, ultimately rendering the aneurysm more resistant to flow forces. Matrix2 coils employ a coil-over-coil design with an integral platinum main coil nominally equivalent to a GDC^®-10 Coil. The main coil is covered with an absorbable biopolymer coil which is typically absorbed by the body within 90 days. The Matrix2 coil is designed to be delivered through a Boston Scientific dual-tip infusion catheter and is equipped with connecting cables and a 1 mA power supply for detachment. GDC 360^° Coils are available in 0.010 and 0.018 inch delivery systems and utilize a push-wire technique. The GDC coils are designed to form a stable threedimensional shape when deployed, formed by an alternating large-loop-small-loop configuration. GDC-18 and GDC- 10 Coils are delivered through Boston Scientific’s “-18” and “-10” infusion catheters, respectively. These can also be used to seal distal coronary perforations.
Flipper^® detachable embolization coils ($78.32; Cook Medical) are 0.038 inch stainless steel coils with synthetic fibers used for peripheral arterial and venous embolization.¹³ They are compatible with 5.0 Fr catheters with a minimum 0.041 inch endhole and are delivered using the Flipper detachable coil delivery system. Nester^® (0.035 and 0.038 inch) and MicroNester^® (0.018 inch) platinum embolization coils provide enhanced radiopacity and magnetic resonance (MR) compatibility and are used for arterial and venous embolization ($78.32; Cook Medical). They are delivered using respectively-sized microcatheters. Tornado^® embolization coils (0.035 inch; Cook Medical) are used for embolization of selective vessel supply to AVMs and tapering vessels. The proximal end-coil design permits delivery using standard 0.035 inch or 0.038 inch wire guides. Tornado^® Embolization Microcoils^™ (0.018 inch) are delivered by saline flush or by the push technique using an appropriately-sized wire guide or pusher. MReye^® embolization coils (0.035 and 0.038 inch) are also used for arterial and venous embolization and have the added advantage of MR compatibility up to 3 Tesla ($78.32; Cook Medical). MReye coils maintain greater radial force than platinum varieties and have higher radiodensity than stainless steel coils, making them more visible under fluoroscopy.
Liquid agents. N-butyl cyanoacrylate (NBCA) glue is an embolic agent that can be used in many of the same settings as coils. The injection of NBCA into an ionic medium such as blood causes the material to polymerize and harden. As a liquid embolic agent, NBCA has the advantage of forming a solid embolic mold inside the target vessel or vessels. However, the successful use of NBCA is highly operator-dependent, requiring meticulous technique and experience to ensure accurate delivery while preventing premature hardening. The ability of NCBA glue to rapidly penetrate and occlude an AVM makes it ideal in this clinical setting.
Foam pledgets. Foam pledget are utilized for the temporary occlusion of small-to-moderate sized vessels typically lasting 1–2 weeks. Gelfoam (Pfizer Inc., New York, New York) is an absorbable thrombogenic gelatin sponge. The Gelfoam is cut into small sections and soaked in contrast medium to increase radiopacity. It is then force-injected or pushed with a guidewire through a catheter positioned at the desired lesion site. A poorlypositioned catheter or poor anterograde flow may cause reflux or embolization to unintended side branches.¹²
Particles. Permanent particles made from polyvinyl alcohol or tris-acryl gelatin microspheres are commercially available in a wide array of preselected sizes ranging from < 100 μm to > 1,000 μm. These thrombogenic particles are a versatile embolic agent for a variety of indications and vessel sizes. The particles are suspended in contrast medium and injected through a delivery catheter at the target vessel. They migrate and wedge into the vessels of corresponding diameters, occluding the artery, by producing fibrosis and thrombosis.¹² Contour SE Microspheres^™ ($765–$1,355.00/box of 5 syringes; Boston Scientific) are polyvinyl alcohol compatible, compressible and injectable spheres that may be used for embolization of hypervascular tumors including leiomyoma uteri and AVMs.¹³ PVA foam embolization particles ($750.00/box of 5 vials; Cook Medical) are similar polyvinyl alcohol spheres available in a wider range of sizes (50–2000 μm).¹⁴ Other embolic tools include temporary gelatin sponge particles which are utilized when the target is a vascular bed, such as a neoplasm, and are not useful when treating a single large-vessel perforation.
Coiling and embolic devices are particularly useful to seal distal perforations owing to their low profile and maneuverability. However, the use of coils and embolic devices in coronary arteries is limited by the permanent loss of the vessel lumen beyond the site of deployment and subsequent infarction. Therefore, vessel occlusion techniques should be limited to life-threatening situations in which no other options are readily available or for the treatment of distal perforations where the amount of myocardial injury is limited.
Conclusion. Coronary artery perforation is a rare, but disastrous, complication of PCI. In this case, successfu management of a CAP with sacrifice of the distal LAD by coil embolization is described. Despite a large, hemodynamically significant perforation, the patient was managed by nonsurgical means, thus avoiding open surgical intervention, which carries a significant mortality risk in this setting. This was possible due to the distal nature of the perforation, compromising coronary flow only to the cardiac apex.
Early recognition and familiarity with all the treatment algorithms for CAP are paramount in the era of complex PCI. An interventional cardiologist needs to be familiar with the various available devices for the management of distal and proximal coronary perforations. This brief review intends to highlight the overall management of perforations, with the focus of the article being on the specific details related to distal perforations. All proximal perforations are ideally treated with covered stents. In the authors’ opinion, an easy and simple approach to distal perforations involves the use of a 3 Fr compatible Interlocking IDC coil ($410.00; Boston Scientific). These embolization devices can be delivered through a 3 Fr Renegade^® Fiber Braided Microcatheter ($399.00; Boston Scientific),13 which requires very little backup for support. Failure rates with this coiling device are low, while major device complications include inadvertent proximal delivery and major vessel occlusion. Dexterity with the use of such devices can be achieved rather quickly. No significant learning curve exists and no pretraining is required; however, in-service sessions with a company-sponsored representative for the cardiologist and catheterization laboratory staff is a prudent approach. The timely recognition and appropriate management of CAP is crucial in reducing the high mortality risk associated with this condition.

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