Case presentation

A 55-year-old man presented for management of a coronary cavernous fistula. One year prior to presentation, this otherwise healthy and active man with a history of hypertension, dyslipidemia, and obstructive sleep apnea developed progressive shortness of breath with exertion. This ultimately progressed to rest dyspnea and he presented to a local hospital with congestive heart failure requiring hospitalization. An echocardiogram found normal systolic function and no valvular abnormalities. Suspicious of coronary artery disease, his physician referred him for cardiac catheterization. To the operator’s surprise, the angiogram revealed a massive right coronary artery to right atrial fistula (Figure 42-1 and Video 42-1) and several fistulous connections from the left circumflex to the right atrium (Figure 42-2 and Video 42-2). The left anterior descending artery appeared normal, with no fistulae identified, and ventricular function was normal.

FIGURE 42-1 This is a right coronary angiogram, showing a large fistula to the right atrium.

FIGURE 42-2 This is a left coronary angiogram showing two discrete fistulae, one proximal (arrow) and one more distal (double arrow), to the right atrium.

Diagnosed with high-output heart failure, he was referred to a surgeon for correction of the fistulae. Surgery consisted of ligation of the right coronary artery with placement of a vein graft to the distal right coronary and ligation of the circumflex fistulae near the atrium. After an uneventful recovery, he did well for several months but then noted increasing dyspnea with fairly minimal exertion; he did not report any chest pain or angina. His symptoms interfered with his ability to work and he was referred for a diagnostic cardiac catheterization.

Cardiac catheterization

Right heart catheterization found fairly normal right sided pressures (mean right atrial pressure of 8 mmHg and pulmonary artery pressure of 27/5 mmHg). The oxygen saturation of blood sampled from the pulmonary artery was 67% with no evidence of a significant left-to-right shunt by oximetry. Cardiac output by the Fick method was 5.07 L/min. Angiography revealed wide patency of the vein graft to the right coronary (Figure 42-3) and continued exclusion of the fistula with no evidence of the fistula from the right coronary (Figure 42-4 and Video 42-3). The left coronary artery demonstrated a single fistulous connection to the right atrium (Figure 42-5 and Video 42-4) representing the distal fistula; the more proximal fistula previously noted was no longer evident.

FIGURE 42-3 This is an angiogram of the patent vein graft to the distal right coronary artery.

FIGURE 42-4 After surgical correction of the fistula, the native right coronary artery remains occluded with no evidence of the previously noted fistula to the right atrium.

FIGURE 42-5 Postoperative angiogram of the left coronary demonstrating the presence of a large, persistent fistula; the smaller, more proximal fistula is no longer present.

His physician decided to pursue percutaneous closure of the remaining fistula, based on the presence of the patient’s ongoing symptoms, which were thought to possibly represent ischemia from “steal.” There was also concern regarding the size of the fistula and the possibility of its further enlargement.

A 6 French 4.5 C-shaped guide catheter was inserted in the left coronary artery, and 50 U/kg of unfractionated heparin was administered. A 300 cm 0.014 inch floppy-tipped guidewire was advanced into the distal circumflex and a second, 300 cm 0.014 inch floppy-tipped guidewire placed into the fistula (Figure 42-6 and Video 42-5). A 4 French JB1 catheter was then advanced over this latter wire and positioned into the fistula and the 0.014 inch guidewire was removed (Figure 42-7). Contrast injected through the JB1 catheter confirmed an acceptable position in the fistula (Video 42-6). A Cook stainless-steel embolization coil (38-4-3) was then advanced through the catheter using a 0.038 inch Cook Newton wire, and positioned into the fistula (Video 42-7). This did not completely occlude the fistula. Thus, a second coil was placed, successfully occluding flow (Figure 42-8 and Video 42-8). The guidewire and catheter were removed from the circumflex artery and a final angiogram was obtained, showing no residual flow in the fistula (Video 42-9).

FIGURE 42-6 With a guide catheter engaged in the left coronary artery, one guidewire was placed in the distal circumflex and a second wire in the fistula.

FIGURE 42-7 A 4 French JB1 catheter (arrow) was advanced into the fistula to allow positioning of the embolization coils.

FIGURE 42-8 Two coils successfully occluded the fistulous connection.

Postprocedural course

His postprocedural course was uncomplicated, and he was discharged after an overnight stay. At follow-up 1 month later, he remained free of symptoms.

Discussion

Coronary cavernous fistulae are abnormal, usually congenital, direct connections between one or more coronary arteries and a cardiac chamber. They are rare, seen in less than 0.5% of angiograms, and are often incidentally found on a coronary angiogram performed for another reason. Coronary fistulae vary greatly in terms of their size, location, and clinical significance. Many fistulae are small and do not result in a measurable shunt; however, very large fistulae may occur, as in this case involving the right coronary artery. They may arise from any of the coronary arteries, but originate most commonly from the right coronary, followed by the left anterior descending artery. Most commonly, they terminate in a right-sided chamber such as the right atrium, right ventricle, coronary sinus, or pulmonary artery. Rarely, they may terminate in the superior vena cava, left atrium, or left ventricle.

Many fistulae are asymptomatic. If symptoms are present, they include angina, dyspnea, and heart failure and are usually caused by a large left-to-right shunt, high cardiac output, or coronary steal and associated ischemia.^1,2 In addition, a fistula may become aneurysmal and rupture, causing hemopericardium, or may become a nidus for infective endocarditis.

The treatment of coronary fistulae depends on their size and complexity and the presence of symptoms. Small fistulae are usually asymptomatic and are often left untreated. Large and symptomatic fistulae are usually closed. Optimal management of asymptomatic but large fistula remains controversial. Some experts advocate their closure in order to prevent late consequences such as aneurysmal dilatation, rupture, and endocarditis.

Surgical techniques are highly effective but are limited by the morbidity associated with major heart surgery. In this case, surgery was highly effective at closing the very large right coronary artery fistula but was less effective at resolving the fistulae originating from the left circumflex artery. This was likely due to the fact that the surgeon approached the circumflex fistulae by attempting to ligate the fistula’s termination in the right atrium and was unable to completely identify all of the connections by this method.

A variety of percutaneous methods to close coronary fistulae have been described, including coils, vascular occlusion plugs, covered stents, and umbrella devices.^3–5 These procedures may be very challenging technically depending on the anatomy, and are effective at closing the fistula in 80% to 85% of cases.³ Complications include device embolization, coronary artery dissection, myocardial infarction, and arrhythmia. Surgery may be preferred in the presence of extreme tortuosity, multiple drainage sites, or the presence of significant coronary artery branches at the site of device delivery.