Surgical Repair of Complex Coronary–Pulmonary Artery Fistulae With Concomitant Coronary Disease and Aortic Stenosis

Abstract

Background

Coronary artery fistulae are rare anomalies that may cause myocardial ischemia or arrhythmias, even in the absence of coronary stenosis. Their presence alongside other structural cardiac diseases complicates diagnosis and management.

Case Summary

A 69-year-old man presented with significant triple-vessel disease including left main stem involvement, moderate aortic stenosis, and complex coronary–pulmonary artery fistulae arising from all 3 coronary territories. He underwent urgent surgery comprising coronary artery bypass grafting, aortic valve replacement, and fistulae ligation. The patient had an uneventful postoperative course and made a good recovery.

Discussion

This case demonstrates how coronary–pulmonary artery fistulae, though rare, can significantly complicate clinical management when coexisting with severe coronary artery disease and valvular pathology.

Take-Home Message

Early recognition of coronary–pulmonary artery fistulae is essential, particularly in the setting of complex cardiac disease, where surgery may be the only effective treatment option.

Graphical Abstract

History of Presentation

A 69-year-old male presented in ventricular fibrillation and required three DC cardioversions over 20 minutes for return of spontaneous circulation. Post intubation, he was transferred to our center, where electrocardiogram confirmed an anterior ST-segment elevation myocardial infarction. A grade 3/6 ejection systolic murmur was auscultated at the aortic area on the precordium.

Take-Home Messages

• •Coronary artery fistulae, though rare, can lead to life-threatening complications such as myocardial ischemia and arrhythmias, even in the absence of coronary stenosis.
• •Prompt recognition and comprehensive surgical management are crucial, especially in complex cases with coexisting cardiac pathology.

Medical History

He had no known ischemic heart disease but significant risk factors including hypertension, hypercholesterolemia, type 2 diabetes, and a strong family history of coronary artery disease.

Investigations

Urgent coronary angiography revealed significant triple-vessel disease with distal left main stem involvement. Notably, a large, complex network of coronary–pulmonary artery fistulae arising from all 3 coronary territories was identified (Figure 1A). Due to the complex anatomy, an intra-aortic balloon pump was inserted, and a primary percutaneous coronary intervention was deferred. Transthoracic echocardiography demonstrated anterior wall hypokinesis with mildly impaired left ventricular systolic function and moderate aortic stenosis. Following multidisciplinary discussion and confirmation of intact neurological status during a sedation break, the patient was scheduled for urgent surgery, as ventilator weaning was deemed unfeasible.

Figure 1.

Angiographic and Intraoperative Views of Coronary–Pulmonary Artery Fistulae

(A) Preoperative coronary angiogram in right anterior oblique caudal view depicting the complex network of fistulae originating from the proximal left anterior descending artery draining toward the pulmonary artery. (B) Intraoperative demonstration of the engorged fistulae over the pulmonary artery.

Management

Intraoperatively, chest wall bruising and a nondisplaced sternal fracture were noted, resulting from prior chest compressions. Upon opening the pericardial cavity, a network of engorged, plexiform coronary–pulmonary fistulae were visualized, arising from all 3 coronary territories and converging into a “fistula lake” overlying the pulmonary artery (Figure 1B). Following the initiation of cardiopulmonary bypass, all accessible fistulae were double-ligated using surgical ties and clips. The heart was arrested with histidine-tryptophan-ketoglutarate cardioplegia (Custodiol; Koehler Chemi). During antegrade root cardioplegia delivery, free efflux was observed from a single pulmonary artery ostium (Video 1), which was oversewn with 5-0 polypropylene suture (Prolene, Ethicon) and obliterated.

Distal anastomoses of the right coronary artery and obtuse marginal artery grafts were performed prior to bioprosthetic aortic valve replacement using a 23-mm Magna Ease valve (Edwards Lifesciences). Following closure of the aortotomy, the left internal thoracic artery was grafted to the left anterior descending artery, and proximal anastomoses of the bypass grafts were completed. Total cardiopulmonary bypass and aortic cross-clamp times were 214 and 152 minutes, respectively.

Outcome and Follow-Up

Postoperatively, the patient was transferred to the cardiac surgical intensive care unit with ongoing inotropic and intra-aortic balloon pump support. A tracheostomy was required for prolonged respiratory weaning, and he was stepped down from intensive care on postoperative day 9. His subsequent recovery was uneventful. At 12-month follow-up, he remained well, with gated cardiac computed tomography (CT) and echocardiography confirming satisfactory fistula obliteration (Figure 2), patent grafts, and a well-seated bioprosthetic valve.

Figure 2.

3-Dimensional Reconstruction From a Gated Cardiac CT Obtained 3 Months Post Discharge

The image was captured during the arterial phase, and there are no active communications to the fistula. Multiple surgical clips used to ligate the fistula are seen.

Discussion

Coronary artery fistula (CAF) is defined as an abnormal communication between a coronary artery and one of the cardiac chambers or a great vessel bypassing the myocardial capillary bed. The vast majority of CAFs are congenital and present as incidental findings during coronary angiography. While most cases are asymptomatic, coronary steal syndrome can cause functional myocardial ischemia even in the absence of coronary artery stenosis.

CAFs were first described by Krause in 1865,¹ with the first successful surgical repair reported by Biörck and Crafoord in 1947.² Although CAFs remain exceedingly rare, their prevalence detected by CT angiography has been reported as high as 0.9%, which is somewhat greater than the traditionally reported prevalence of 0.002% to 0.3% derived from invasive angiography datasets.³ Multiple classification systems exist based on anatomical features such as fistula origin, drainage site, complexity, and association with other cardiac anomalies. Clinically, the fistula's drainage site is of critical importance, as the termination site combined with the resistance within the anomalous vessel dictates the resultant pathophysiology. Accordingly, fistulae are generally classified as either coronary cameral—draining into a cardiac chamber—or coronary arteriovenous—draining into the pulmonary or systemic circulation.

Historically, coronary angiography has served as the reference standard for CAF diagnosis and assessment. Echocardiography, both transthoracic and transesophageal, can also provide valuable anatomical and hemodynamic information. More recently, cross-sectional imaging modalities, particularly CT angiography, have been utilized for precise anatomical delineation and procedural planning. The shorter acquisition time and superior temporal and spatial resolution of CT angiography compared to magnetic resonance imaging have positioned CT as the preferred imaging modality, barring contraindications.^3,4 From a functional perspective, myocardial perfusion single-photon emission computed tomography and invasive coronary angiography with a fractional flow reserve assessment have been employed to evaluate myocardial ischemia, especially in cases where a coronary steal phenomenon is suspected.⁵

Liberthson et al⁶ advocated for early elective ligation of CAFs in all patients due to the high incidence of late symptoms and complications, as well as increased morbidity and mortality observed with delayed intervention in older patients. The 2008 American College of Cardiology and American Heart Association guidelines recommend interventional management as a Class I indication for all large fistulas, regardless of symptoms, and for small to medium fistulas in symptomatic patients with myocardial ischemia, arrhythmia, ventricular dysfunction, or endarteritis.⁷ Treatment options include surgical ligation and percutaneous closure with many groups describing an array of innovative approaches.8, 9, 10 The complexity of the fistula network, with origins from all 3 coronary territories, along with the coexistence of severe triple-vessel disease and aortic stenosis, significantly limited the feasibility of percutaneous intervention, making a single-setting surgical approach the most comprehensive treatment option in this case.

Conclusions

In our patient, a complex network of coronary-to-pulmonary artery fistulae resembling a “Cor medusae” was incidentally identified. Given the patient's critical condition, further cross-sectional imaging was precluded. Our operative strategy was to address all cardiac pathology in a single surgical setting to optimize the potential for myocardial recovery.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Appendix

Video 1

A Narrated Overview of the Successful Surgical Management of This Complex Pathology