Invited Review

Coronary-pulmonary artery fistula in tetralogy of Fallot with pulmonary atresia

Asian Cardiovascular & Thoracic Annals 2014, Vol. 22(8) 1003–1009 ß The Author(s) 2013 Reprints and permissions: DOI: 10.1177/0218492313505101

Sachin Talwar1, Robert H Anderson2, Vikas Kumar Keshri1, Shiv Kumar Choudhary1, Gurpreet Singh Gulati1 and Balram Airan1

Abstract Surgical correction of patients with tetralogy of Fallot with pulmonary atresia is now one of the routine procedures performed by pediatric cardiac surgeons. In one variant, the pulmonary arterial supply is derived from a fistulous communication from the coronary arteries. This rare and interesting situation poses a diagnostic and therapeutic dilemma, as well as providing specific management challenges to the surgical team. Here, we discuss important aspects of this rare variant, specifically its morphology, presentation, evaluation and management.

Keywords Arterio-arterial fistula, heart defects, congenital, fistula, pulmonary atresia, tetralogy of Fallot

Introduction Tetralogy of Fallot with pulmonary atresia is defined as no direct continuity between the cavities of the right ventricle and the pulmonary trunk. Of necessity in such circumstances, there must be alternative sources of flow of blood to the lungs. In most instances, the flow is through a persistently patent arterial duct or large systemicto-pulmonary collateral arteries. Much less frequently, the supply is derived via an aortopulmonary window or fistulous communication from the coronary arteries.1–5 The latter arrangement was first reported in 1950 by Allanby and colleagues6 from Guy’s Hospital in London. Subsequently, there have been several accounts of fistulous communications as the predominant source of pulmonary arterial supply.7–13 Dabizzi and colleagues,4 perhaps surprisingly, argued that one-tenth of their large series of patients studied angiocardiographically had such fistulous communications from the coronary arteries, but all the identified fistulas were small. The presence of such collateral channels nonetheless has important clinical and surgical implications.

Sources of pulmonary blood flow in tetralogy of Fallot with pulmonary atresia A persistently patent arterial duct is the major source of arterial flow to the lungs in approximately

two-thirds of cases.1,2 In most other patients, the major source is through collateral arteries, most of which arise from the descending thoracic aorta.1 The collateral arteries can also arise from the abdominal aorta or one of its branches, the subclavian vessels, or the coronary arteries. Other rare sources of collateral supply include aortopulmonary windows and persistence of the evanescent artery of the fifth aortic arch.1,6 It is very rare for major collateral arteries to supply a lung that was initially fed through a persistently patent arterial duct.1–3,15–17 We are aware of less than 40 patients reported in the English medical literature in whom fistulous communication from the coronary arteries have provided the predominant or a significant source of pulmonary arterial supply.7–9,12,18 In physiological and hemodynamic terms, fistulous communications from the coronary

1 Cardiothoracic Centre, All India Institute of Medical Sciences, New Delhi, India 2 Institute of Genetic Medicine, Newcastle upon Tyne, UK

Corresponding author: Sachin Talwar, MCh, Department of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, New Delhi 110029, India. Email: [email protected]


Asian Cardiovascular & Thoracic Annals 22(8)

arteries are more likely to supply through the arterial duct than the more usual systemic-to-pulmonary collateral arteries. The fistulous communications typically supply the entirety of intrapericardial pulmonary arterial bed, feeding the arteries in antegrade fashion, as does the arterial duct. The systemic-to-pulmonary collateral arteries in contrast either do not make any connections with the intrapericardial pulmonary arteries or else feed the pulmonary arteries within the lung parenchyma or at the hilum.

Morphology Blood supply via fistulous communications from the coronary arteries exists either when the fistula is the solitary or predominant source of supply,8,9 or when it exists along with additional sources of pulmonary flow.18 Among the reported cases of patients with predominant arterial supply through fistulous communications, only three-fifths had additional associated major collateral arteries.19 The fistulous communication itself can arise from either the left or right coronary artery. Among the cases we reviewed, three-quarters had the fistula arising from the left coronary artery.7–9,12,18 In a few cases, the fistula was described as arising from a solitary coronary artery, most commonly the left, which then supplied both coronary arterial systems.7,9 In most cases involving the left coronary arterial system, the fistula arose from the anterior interventricular artery, followed by the main stem of the left coronary artery, and less frequently from the circumflex artery.9,18 When the right coronary arterial system has been involved, the fistula was always described as arising from its proximal segment. Most frequently, the fistula itself terminates in the pulmonary trunk, typically after taking a varying tortuous course. More rarely, the fistula itself can give rise to major systemic-to-pulmonary collateral arteries that then extend into the pulmonary parenchyma, rather than supplying the lungs through the intrapericardial pulmonary arteries.18,19 This is an important distinction because the latter type of collateral arteries can regress spontaneously.7 In most instances, the intrapericardial pulmonary arteries are confluent and of good size, although rarely, they may be hypoplastic. It is almost certainly the presence of antegrade flow that permits growth of the intrapericardial pulmonary arteries despite pulmonary atresia.7 The pattern of flow in the intrapericardial pulmonary arteries in these cases is similar to the duct-dependent flow seen in the majority of patients with tetralogy of Fallot and pulmonary atresia.22 In all cases, the coronary artery giving rise to the fistula is dilated proximally (Figure 1).13 The distal course of the coronary artery giving rise to the fistula is otherwise normal in terms of caliber, flow and function.8,9

Figure 1. An angiogram obtained by injecting the main stem of the left coronary artery, shown in left lateral view, reveals the dilated main stem (LMCA) and its proximal anterior interventricular branch (LAD) proximal to the site of the fistulous communication, with the pulmonary arteries filling through the fistula. The circumflex artery and LAD distal to the site of the fistulous communication are of normal calibre.8

Hemodynamic and physiologic effects In all cases reported to date, the coronary artery proximal to the site of the fistula has been enlarged, supplying blood to both the pulmonary and coronary arteries.8 This leads to transmission of unrestricted systemic pressures to both distal beds. Thus the coronary arterial flow is not dependent on the pulmonary flow. Rather, it is more dependent on flow to the distal coronary arterial bed. Because of this, there is no coronary steal phenomenon, and as far as we are aware, no reported instances of myocardial ischemia. Because these patients have significant flow into their pulmonary arteries, they usually have minimal or mild cyanosis, along with relatively well-developed and confluent intrapericardial pulmonary arteries.18 If untreated, long-standing hypoxemia and their inability to increase the flow of blood to the lungs during exercise, eventually results in dyspnea. The size of the communication between the coronary artery and the pulmonary arteries is typically restrictive, and hence there is only mildto-moderate elevation of pulmonary arterial pressures.9 The theoretical risk of development of pulmonary vascular disease cannot be excluded. Indeed, we are aware of at least 3 patients with features of pulmonary arterial hypertension.7,8,20 Of these 3 patients, 2 were in their fourth to fifth decade of life,8,20 and the other was found to be inoperable at the age of 7 years due to severe pulmonary arterial hypertension.10 In the overall group of patients, flow to the lungs is dependent on the size of the pulmonary arteries and their capacity to accommodate the flow. In patients with hypoplastic and restrictive pulmonary arteries the pulmonary flow is therefore reduced.12 It is important to identify such

Talwar et al.


Figure 2. (a) Volume-rendered reconstruction of a computed tomogram showing confluent pulmonary arteries of good size, and the pulmonary end of the fistula (*). (b) An axial thick multiplanar reconstruction revealing the fistula originating from the anterior interventricular coronary artery (*). Ao: aorta; PA: pulmonary trunk.8

situations as early as possible, even if there are other potential sources of pulmonary flow.

Clinical presentation and diagnosis Age at presentation can vary from early infancy to late adulthood.20,22 The mode of clinical presentation is no less variable. The presenting features range from asymptomatic patients to those exhibiting severe cyanosis, or the finding being diagnosed incidentally at the time of open heart surgery. Cyanosis is the most common presenting feature.7,22 Should there be excessive pulmonary flow, then patients may present with congestive failure.22 As we have already discussed, pulmonary hypertension can develop, but this is also very rare.23 The presence of a fistulous communication can be suspected after echocardiographic investigation, but diagnosis is made most often on cardiac catheterization, and confirmed in the operating room. In some reported cases, the diagnosis was not established until after death. In some patients, a fistula may be suspected if repeated attempts to advance a catheter into the distal pulmonary arteries result in repeated slipping of the catheter from the pulmonary trunk into a distal coronary artery. A selective root angiogram along with a selective coronary angiogram is then all that is required to confirm the diagnosis. The major lesions to be excluded in the differential diagnosis are aortopulmonary window and a common arterial trunk. In the

setting of a window, there is usually pulmonary hypertension and dilation of the intrapericardial pulmonary arteries. The finding of low to normal pulmonary arterial pressures favors the presence of a fistulous communication.13 In patients with a common arterial trunk, the pulmonary arteries arise directly from the trunk itself, which exits from the base of the heart through a common truncal valve.13

Evaluation and management Clinical evaluation should aim to confirm the diagnosis, define the anatomy, evaluate the coronary arteries, confirm the presence or absence of additional collateral arteries and their physiological significance, and define the precise nature of the pulmonary arterial supply and the structure of the outflow tract from the right ventricle. To achieve these aims, a complete workup requires angiocardiography to define the cardiac anatomy and demonstrate the fistula, selective root aortography to determine the anatomy of the fistula for better delineation of the collateral arteries, selective coronary angiography to delineate the origin, course, and connection of the fistula along with the coronary arterial distribution, and an injection into the descending thoracic aorta to confirm the presence or absence of additional collateral arteries.8,9 Selective injections into the brachiocephalic, carotid, and subclavian arteries are often needed to exclude additional collateral arteries.24 For the success of one-stage correction and


Asian Cardiovascular & Thoracic Annals 22(8)

Figure 3. Multiplanar reconstructions in the coronal oblique plane, showing the aorta (Ao), pulmonary trunk (PA), fistula (*), and left anterior descending artery (arrow).

Figure 4. Volume-rendered reconstruction of the fistula (*) from the main stem of the left coronary artery to the pulmonary trunk (PA).

unifocalization, it is essential to identify the pulmonary arterial supply to all lung segments. Hence an aggressive approach to cardiac catheterization is recommended, entering each collateral vessel to measure the pressure and perform angiography. This provides a roadmap to subsequent unifocalization.24 Computed tomographic angiography is becoming increasingly important in delineating all sources of pulmonary flow, and in ascertaining whether collateral arteries are providing the sole supply to the lung (Figures 2– 5). These investigations of course supplement standard echocardiography which remains the mainstay of defining the intracardiac anatomy.

Surgical correction The essential goals of surgical correction are to close the fistulous communication, to ensure unhindered coronary arterial flow, to close the ventricular septal defect

Figure 5. Computed tomography angiogram showing the right coronary artery (*) arising from the aorta (Ao) and forming a fistulous tract that continues into the right pulmonary artery (R). The left pulmonary artery (L) is very small.

with relief of right ventricular outflow obstruction, and to establish unobstructed continuity between the right ventricle and the intrapericardial pulmonary arteries. Often, this may be combined with ligation or unifocalization of additional collateral arteries. Closure of the fistulous communication depends on whether there is an additional source of supply to the lungs. If found, additional sources are treated by ligation and division immediately upon institution of cardiopulmonary bypass and prior to administration of cardioplegia. If providing the sole source of supply, the fistula needs to be surgically unifocalized.8,18,24 This is best achieved by oversewing the fistula from within the pulmonary trunk. This avoids any dissection of the coronary arteries, especially of the dilated upstream portion, and prevents injury or interruption of important branches. This approach also decreases the chances of

Talwar et al.


Figure 6. A diagram of the patient anatomy depicted in Figures 1 and 2, showing (a) the fistula from the LAD crossing the right ventricular outflow tract, (b) the opened pulmonary trunk and the opened right ventricular outflow tract, with a gap of 1 cm between the openings crossed by the dilated LAD, and (c) direct closure of the fistula with the gap now bridged by a fresh autologous pericardial patch. CAPA: fistulous communication; LAD: anterior interventricular coronary artery.8

iatrogenic coronary arterial injury. Closure through this approach also means that the opening of the fistula is readily accessible, and the approximation and closure of its margins is possible with fairly low tension on the suture line.18,23 The standard approach to a one-stage repair is through a median sternotomy, using hypothermic cardiopulmonary bypass. Upon opening the thoracic cavity, any additional collateral arteries are identified and looped. The aorta and the pulmonary trunk are separated from each other, and the intrapericardial pulmonary arteries are dissected and mobilized to the hilum of both lungs, and looped. Immediately after institution of cardiopulmonary bypass with bicaval cannulation, any additional collateral arteries are ligated. The right and left pulmonary arteries are temporarily occluded with vascular loops to prevent runoff into the pulmonary circulation as well as coronary arterial steal. It is only after these maneuvers that

cardioplegia is administered. The pulmonary trunk is then opened between stays to identify the opening of the fistula, and the fistula is closed using a patch. The final step is to close the ventricular septal defect and reconstruct the right ventricular outflow tract, following the usual protocol for any patient with tetralogy of Fallot.23 In cases where detachment of the pulmonary trunk is likely to result in kinking or damage to the coronary arteries, the posterior wall of the outflow tract is constructed using a pericardial patch, and the anterior portion is hooded with a homograft or pericardial patch (Figure 6). Use of a valved homograft conduit also remains an option in such cases.8

Staged vs. single-stage repair The need for staging may sometimes arise due to various presentations and variations in the anatomy of the disease. In neonates, early ligation of fistula with

1008 establishment of antegrade pulmonary blood flow through a systemic-to-pulmonary arterial shunt, or placement of a conduit from the right ventricle to the pulmonary arteries, are alternative options. This is followed by intracardiac repair when the child is older and gains weight.8 In such patients, if the situation demands, the procedures are staged in 3 phases. The first involves creation of a shunt and division of the fistula, preserving the native tissue. The second stage is to reconstruct the right ventricular outflow tract using the native tissue, along with occlusion of the prosthetic shunt. The final stage is to close the ventricular septal defect.19 Alternatively, in children with large collateral arteries, when there may be concern about the development of obstructive pulmonary vascular disease, the first stage may involve ligation of the collateral arteries to decrease the pulmonary blood flow, followed by division of the fistula, fixing the stump of the pulmonary trunk to the right ventricle and creation of a systemic-to pulmonary-arterial shunt, followed by closure of the ventricular septal defect, reconstruction of the outflow tract, and plugging of the prosthetic shunt in the third stage.19 In most of these patients, a single-stage operation remains the preferred approach.8,24 This is reported to be possible in almost all patients, with encouraging early and midterm results.24–26 The recommended requirements for single-stage repair include a central pulmonary arterial area at least half of normal, and at least one whole lung’s worth of pulmonary segments.25 Patients who do not meet these criteria are subjected to staged repair. The advantage of a single-stage repair is that it shortens the duration over which the collateral arteries are exposed to systemic pressures, thus decreasing the chances of myointimal hyperplasia and eventual occlusion.21,26 It also prevents the development of pulmonary vascular occlusive disease in the segments supplied by the large collateral arteries or prosthetic systemic-to-pulmonary arterial shunts. In addition, the scarring and distortion of the pulmonary arteries by multiple surgical procedures and prosthetic conduits is prevented, as well as loss of recruitable lung segments.

Follow-up and outcomes As yet, there has been no reported large series with which to define the adequacy of follow-up and outcomes. However, various case reports have described a favorable outcome subsequent to surgical correction.

Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Asian Cardiovascular & Thoracic Annals 22(8) Conflicts of interest statement None declared.

References 1. Liao PK, Edwards WD, Julsrud PR, Puga FJ, Danielson GK and Feldt RH. Pulmonary blood supply in patients with pulmonary atresia and ventricular septal defect. J Am Coll Cardiol 1985; 6: 1343–1350. 2. Schneeweiss A, Shem-Tov A, Dicker D, Blieden LC, Deutsch V and Neufeld HN. The pulmonary circulation ling its systemic arterial supply in pulmonary atresia. Clin Cardiol 1982; 5: 489–492. 3. Venables AW. The patterns of pulmonary circulation in pulmonary atresia. Br Heart J 1964; 26: 760–769. 4. Haworth SG and Macartney FJ. Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. Br Heart J 1980; 44: 14–24. 5. Haworth SG. Collateral arteries in pulmonary atresia with ventricular septal defect: a precarious blood supply. Br Heart J 1980; 44: 5–13. 6. Allanby KD, Brinton WD, Campbell M and Gardner F. Pulmonary atresia and the collateral circulation to the lungs. Guys Hosp Rep 1950; 99: 110–152. 7. Najm HK, Jha NK, Godman M, Mutairi MA, Rezk AI and Momenah T. Pulmonary atresia, VSD in association with coronary-pulmonary artery fistula. Asian Cardiovasc Thorac Ann 2007; 15: 335–338. 8. Garg P, Talwar S, Kothari SS, et al. Management of pulmonary arterial supply dependent on a coronary arterial fistula in a patient with tetralogy of Fallot with pulmonary atresia. World J Pediatr Congenit Heart Surg 2012; 3: 499–503. 9. Talwar S, Sharma P, Gulati GS, Kothari SS and Chaudhary SK. Tetralogy of Fallot with coronary artery to pulmonary artery fistula and unusual coronary pattern: missed diagnosis. J Card Surg 2009; 24: 752–755. 10. Pahl E, Fong L, Anderson RH, Park SC and Zuberbuhler JR. Fistulous communications between a solitary coronary artery and the pulmonary arteries as the primary source of pulmonary blood supply in tetralogy of Fallot with pulmonary valve atresia. Am J Cardiol 1989; 63: 140–143. 11. Rastelli GC, Ongley PA, Davis GI and Kirklin JW. Surgical repair for pulmonary valve atresia with coronary-pulmonary artery fistula: report of case. Mayo Clin Proc 1965; 40: 521–527. 12. Metras DR, Kreitmann B, Tatou E, Riberi A and Wernert F. Tetralogy of Fallot with pulmonary atresia, coronary artery-pulmonary artery fistula, and origin of left pulmonary artery from descending aorta: total correction in infancy. J Thorac Cardiovasc Surg 1993; 105: 186–188. 13. Krongrad E, Ritter DG and Kincaid OW. Aorticopulmonary tunnel: angiographic recognition of pulmonary atresia and coronary arteryto-pulmonary artery fistula. Am J Roentgenol Radium Ther Nucl Med 1973; 119: 498–502.

Talwar et al. 14. Dabizzi RP, Caprioli G, Aiazzi L, et al. Distribution and anomalies of coronary arteries in tetralogy of Fallot. Circulation 1980; 61: 95–102. 15. Thiene G, Bortolotti U, Gallucci V, Valente ML and Volta SD. Pulmonary atresia with ventricular septal defect. Further anatomical observations. Br Heart J 1977; 39: 1223–1233. 16. Thiene G, Frescura C, Bortolotti U, Del Maschio A and Valente M. The systemic pulmonary circulation in pulmonary atresia with ventricular septal defect: concept of reciprocal development of the fourth and sixth aortic arches. Am Heart J 1981; 101: 339–344. 17. Bharati S, Paul MH, Idriss FS, Potkin RT and Lev M. The surgical anatomy of pulmonary atresia with ventricular septa1 defect pseudotruncus. J Thorac Cardiovasc Surg 1975; 69: 713–721. 18. Collison SP, Dagar KS, Kaushal SK, Radhakrishanan S, Shrivastava S and Iyer KS. Coronary artery fistulas in pulmonary atresia and ventricular septal defect. Asian Cardiovasc Thorac Ann 2008; 16: 29–32. 19. Kaneko Y, Okabe H, Nagata N, Kobayashi J, Murakami A and Takamoto S. Pulmonary atresia, ventricular septal defect, and coronary-pulmonary artery fistula. Ann Thorac Surg 2001; 71: 355–356. 20. Vigneswaran WT and Pollock JC. Pulmonary atresia with ventricular septal defect and coronary artery fistula: a late presentation. Br Heart J 1988; 59: 387–388. 21. Reddy VM, Liddicoat JR and Hanley FL. Midline onestage complete unifocalization and repair of pulmonary







atresia with ventricular septal defect and major aortopulmonary collaterals. J Thorac Cardiovasc Surg 1995; 109: 832–844. Solowiejczyk DE, Cooper MM, Barst RJ, Quaegebeur JM and Gersony WM. Pulmonary atresia and ventricular septal defect with coronary artery to pulmonary artery fistula: case report and review of the literature. Pediatr Cardiol 1995; 16: 90–94. Krongrad E, Ritter DG, Hawe A, Kincaid OW and McGoon DC. Pulmonary atresia or severe stenosis and coronary artery to pulmonary artery fistula. Circulation 1972; 46: 1005–1012. Amin Z, McElhinney DB, Reddy VM, Moore P, Hanley FL and Teitel DF. Coronary to pulmonary artery collaterals in patients with pulmonary atresia and ventricular septal defect. Ann Thorac Surg 2000; 70: 119–123. Puga FJ, Leoni FE, Julsrud PR and Mair DD. Complete repair of pulmonary atresia, ventricular septal defect, and severe peripheral arborization abnormalities of the central pulmonary arteries. Experience with preliminary unifocalization procedures in 38 patients. J Thorac Cardiovasc Surg 1989; 98: 1018–1029. Reddy VM, McElhinney DB, Moore P, Amin Z, Teitel DF and Hanley FL. Early and intermediate outcomes after repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 85 cases. Circulation 2000; 101: 1826–1832.

Coronary-pulmonary artery fistula in tetralogy of Fallot with pulmonary atresia.

Surgical correction of patients with tetralogy of Fallot with pulmonary atresia is now one of the routine procedures performed by pediatric cardiac su...
2MB Sizes 1 Downloads 3 Views