Coronary Cameral Fistula A Concern In Cardiac Surgery
CORONARY CAMERAL FISTULA A CONCERN IN CARDIAC SURGERY
AUTHORS
Dr. Venkatavijay.K, (HOD department of CTVS ASRAM ELURU), Dr.Chaitanya.P, Dr. Abhilash.T,. Department of CTVS –ASRAM Medical College and hospital, ELURU.
ABSTRACT
Coronary–cameral fistulas (CCFs) are mostly congenital in origin and rarely acquired. Clinical symptoms are decided by the hemodynamic significance of the coronary fistula. Even in asymptomatic patients, it is essential to know about coronary CCF particularly if the patient is to undergo cardiac surgery with cardioplegic cardiac arrest. Incidental finding of coronary CCF should never be ignored. Intraoperative myocardial protection and methods used are significantly influenced by such fistula.
Keywords: Coronary fistula, coronary steal phenomenon, myocardial protection
Case report
A 50-year-old male presented with shortness of breath on mild exertion. Transthoracic echocardiography examination revealed severe mitral stenosis. The patient was scheduled for mitral valve replacement surgery. Preoperatively, the patient underwent coronary angiography. No significant obstructive lesion was observed in coronary arteries. However, fistulous connection was noted from left artery to left atrium. Contrast was shunted to left atrium (LA) chamber during angiography [Videos 1 and 2]. After anesthesia induction, midline sternotomy was performed followed by aortic and bicavalcannulation after heparinization. Before antegradecardioplegia, pulmonary artery venting was done with vent catheter before giving cardioplegia.LA was also decompressed with the LA vent. In this way LV was reasonably empty for performing a mitral valve replacement after diastolic arrest. Diastolic arrest was achieved and LA was openedand a large organized clot was present in the left atrial appendage above the left superior pulmonary vein. On removing the organized clot the opening of the left cameral fistulae was present at the junction of left superior pulmonary vein and left atrium. Hence as it was not giving us any problem during mitral valve replacement surgery which could be performed uneventfully we left out the cameral fistula without disturbing it as it may obstruct the left superior pulmonary opening into the LA. Patient could be weaned off cardiopulmonary bypass with minimal inotropic support. LV function was good echocardiographically.
Keywords: Coronary fistula, coronary steal phenomenon, myocardial protection
INTRODUCTION
Coronary–cameral fistula (CCF) is an anomalous connection between cardiac chamber and coronary artery. Apart from the cardiac chamber, coronary artery fistula can also communicate with a major vessel (venae cavae, pulmonary artery, veins, or coronary sinus). CCFs are discovered incidentally in 0.1% of patients undergoing coronary angiograms.
Coronary cameral fistulae are present in less than 1% of the population and are present in 0.1% to 0.2% of coronary angiographic studies.[2][4] They account for 0.2 to 0.4% of congenital anomalies of the heart. Around half of the coronary vasculature anomalies seen in children are coronary artery fistulae. Coronary cameral fistulae are diagnosable at any age. However, diagnosis is usually in early childhood, when an asymptomatic child or child with symptoms of heart failure presents with a heart murmur. No gender or race predilection has been noted in patients with coronary cameral fistulae.
CASE PRESENTATION
50 years old Patient named Chinna Rao was having breathless on exertion grade III NYHA, class for 3 years and he was taking medication from cardiologist on presentation to our OPD he was found to have loud first heart sound,mid diastolic murmur clinically on investigation with 2D echo he was diagnosed to have CRHD with severe mitral stenosis with LA clot. He was subjected to angiogram as he was 50 years and he was found to have normal coronal arteries but incidentally his left circumflex coronary artery was draining into the left atrium through a abnormal fistulous tract, hence the diagnosis of coronary cameral fistula was made.
PREOPERATIVE DIAGNOSIS
CRHD with severe MS with LA clot with severe PAH with NYHA class III with normal sinus rythm
Coronary cameral fistula draining from the left circumflex coronary artery to left atrium.
SURGICAL PROCEDURE
After anesthesia induction, and intraoperative central line and invasive pressure monitoring midline sternotomy was performed followed by aortic and bicaval cannulation after heparinization. Before antegrade cardioplegia was given, pulmonary artery venting was done with vent catheter. LA vent was also introduced to decompress the LA with a vent catheter. In this way LV was reasonably empty for performing a mitral valve replacement after diastolic arrest. Diastolic arrest was achieved and LA was opened and a large organized clot was present in the left atrial appendage above the left superior pulmonary vein. On removing the organized clot the opening of the left cameral fistulae was present at the junction of left superior pulmonary vein and left atrium. Hence as it was not giving us any problem during mitral valve replacement surgery which could be performed uneventfully we left out the cameral fistula without disturbing it as it may obstruct the left superior pulmonary opening into the LA. Patient could be weaned off cardiopulmonary bypass with minimal inotropic support. LV function was good echocardiographically.
INTRAOPERATIVE FINDINGS
Organized LA clot Coronary cameral fistula Thickened fibrosed and calcified mitral valve with subvalvular fusion POSTOPERATIVE PERIOD was uneventful.
Discussion
Coronary–cameral fistulas (CCFs) are mostly congenital in origin and rarely acquired.[1] Congenital fistula can be an isolated finding or associated with other congenital heart abnormalities such as severe left or right outflow tract obstruction in aortic atresia with hypoplastic left heart syndrome or pulmonary atresia with intact interventricular septum, respectively. Acquired coronary artery fistulas are uncommon and are secondary to trauma or interventional procedures such as stab/gunshot wound, cardiac catheterization, angioplasty, endomyocardial biopsy, or pacemaker implantation.[1] Majority of such fistulas originate from right coronary artery (52%) followed by left anterior descending artery (30%) and left circumflex artery (18%).[7] More than 90% of the fistulas terminate in the right side of the heart[9] and rarely into left ventricle or pericardium. Hence, there can be left-to-right shunt or a left-sided volume overload if fistula drainage is in the right or left cardiac chamber, respectively. Reported incidence of coronary artery-LV fistula is merely 1.2% of all coronary artery fistulae.[7] Clinical symptoms are decided by the hemodynamic significance of the coronary fistula and which is dependent on its size, resistance of the recipient chamber, and myocardial ischemia.[8] Although most fistulas are small and asymptomatic, untreated hemodynamically significant fistula can present clinically in 19% of patients with age <20 years and 63% of the patients with age >20 years. Coronary artery fistula can potentially cause myocardial ischemia by coronary artery steal phenomenon.[9,10] Myocardial ischemia was demonstrated on treadmill test and Holter monitoring in patients with coronary artery fistula.[11] Acute myocardial infarction due to coronary steal phenomenon by coronary artery fistula has also been reported.[10] Moreover, fistula with hemodynamically significant left-to-right shunt may lead to congestive heart failure and pulmonary artery hypertension. Other reported complications are thrombosis and/or embolism, endocarditis, rupture, atrial fibrillation, premature atherosclerosis, and sudden cardiac death.[12,13] Although echocardiography can show large coronary artery fistula, coronary angiography not only diagnoses it but can also demonstrate the size, anatomy, number, origination, and termination site of the fistulas. Multidetector computed tomography and magnetic resonance imaging can also be useful to evaluate the anatomy, flow, and function of CCF.[9] Symptomatic patients with large, hemodynamically significant fistulas warrant surgical or percutaneous catheter closure. Clinically, silent and hemodynamically insignificant fistula may not need corrective treatment. However, such patients need regular follow-up as smaller fistulas can get bigger with the age.[1] Even in asymptomatic patients, it is essential to know about coronary CCF particularly if the patient is to undergo cardiac surgery with cardioplegic cardiac arrest. Coronary CCF can potentially affect myocardial protection intraoperatively. In patients with coronary-LV fistula, administration of antegrade cardioplegia will significantly shunt cardioplegic solution to LV cavity. Distended ventricular chamber would increase the wall stress which is not at all favorable for myocardial protection. Cardioplegic delivery to the myocardium may not be adequate and effective. Keeping the vent in the LV before antegrade cardioplegia can decompress the ventricle in such cases. However, retrograde cardioplegia through coronary sinus can alleviate these problems and simultaneously provide good myocardial protection. In the present case, CCF was surgically addressed by putting a pulmonary artery vent and evacuating and it was not causing LA congestion and LV dilatation. Incidental finding of coronary cameral fistula should never be ignored. Intraoperative myocardial protection and methods used to decrease the LA and LV congestion like pulmonary artery venting .
PROGNOSIS
Life expectancy for patients with a coronary cameral fistula is normal. Results from studies indicate that both transcatheter and surgical approaches for management are associated with a good prognosis. The need for additional surgery to treat recurrent disease only presents in around 4% of patients.
COMPLICATIONS
Common complications associated with coronary cameral fistulae include:
Cardiac ischemia Congestive heart failure Cardiac arrhythmia Infective endocarditis Rupture of coronary cameral fistula.[3] Complications related to the management of coronary cameral fistulae (transcatheter embolization vs. surgical closure) are as follows Complications of transcatheter embolization Coronary artery spasm Ventricular arrhythmia Coronary artery perforation or dissection Cardiac ischemia from coronary artery thrombosis or improper positioning of occlusive devices Complications of surgical closure Cardiac ischemia or myocardial infarction Recurrence of coronary cameral fistula.[2]
Conclusion
Patients with coronary cameral fistulae should be managed by an inter professional team that includes an interventional cardiologist, a cardiac surgeon, a radiologist, a pharmacist, and a nurse practitioner. Well planning before undergoing any cardiac surgery using cardio pulmonary bypass is required to elemenate the intra operative complications.
In general, small coronary cameral fistulae should be observed only with close echocardiographic or angiographic follow up to determine the enlargement of feeding vessels over time. Small fistulae have typically benign course, asymptomatic, and even may close spontaneously.[4][1] Large fistulae require closure. There are two approaches for the closure of coronary cameral fistulae: transcatheter embolization and surgical closure. The choice of approach for closure of these fistulae depends on the expertise of the team involved in taking care of the patient. Furthermore, the surgical approach would be more appropriate in patients with large fistulae, fistulae with multiple openings, aneurysmal dilatation, or acute angulations that are not amenable to catheterization.[10][11] Moderate to large fistulae without symptoms are managed based on the location of the fistula. For proximal fistulae, closure (transcatheter or surgical) is the recommendation. Antiplatelet therapy should be initiated after closure and continued for at least one year. On the other hand, for distal fistulae, there are two possible approaches for management. The first approach is observation with the use of antiplatelet therapy indefinitely. The second approach is the closure of the fistula, followed by the use of antiplatelet therapy for one year.
