Repair of Unilateral Absence of Right Pulmonary Artery With Contralateral Pulmonary Artery Autograft Interposition in an Infant Mehmet Salih Bilal, MD, Ozgur Yildirim, MD, Mustafa Avsar, MD, and Arda Ozyuksel, MD Department of Cardiovascular Surgery, Medicana International Hospital, and Department of Cardiovascular Surgery, Medipol University, Istanbul, Turkey
Unilateral absence of the pulmonary artery (PA) is a rare congenital abnormality. Although a traditional 2-stage approach with a preceding systemic-to-PA shunt followed by a definitive repair is mandatory in patients with absent extrapericardial pulmonary arteries, more creative solutions are necessary when 1-stage repair is concerned. We present a novel technique for repairing the absent intrapericardial
right pulmonary artery (RPA) with a contralateral PA autograft segment interposition. We believe that this technique using solely autologous tissue is effective in patients in whom the intrapericardial segment of the PAs is absent.
C
RPA at the right hilum was 4 mm (Fig 1). Main and left PA diameters were 10 mm and 7 mm, respectively. The distance between the RPA at the right hilum and the MPA was 2.6 cm. Two separate aortopulmonary collateral vessels were identified between the ascending aorta and the extrapericardial segment of the RPA at the right hilum. Cardiac catheterization was performed for further diagnostic evaluation. The systolic and diastolic pressures measured at the right ventricle, MPA, and ascending
Technique The patient was a 2-month-old boy (body weight, 6 kg). He had symptoms of congestive heart failure. The echocardiographic evaluation revealed a 5-mm subpulmonic ventricular septal defect (VSD), a nonconfluent RPA, a patent ductus arteriosus, a patent foramen ovale, and pulmonary hypertension. Preoperative computed tomographic angiography demonstrated the absence of an intrapericardial RPA, and the largest diameter of the Accepted for publication Dec 16, 2014. Address correspondence to Dr Ozyuksel, Department of Cardiovascular Surgery, Medipol University, TEM Goztepe Cikisi No. 1, Bagcilar, Istanbul, Turkey; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Fig 1. Preoperative contrast-enhanced computed tomographic scan reveals the absence of intrapericardial segment of right pulmonary artery (RPA), which continues at the right hilum (arrow). (aAo ¼ ascending aorta; dAo ¼ descending aorta; LPA ¼ left pulmonary artery; MPA ¼ main pulmonary artery.) 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.12.036
FEATURE ARTICLES
ongenital unilateral absence of a pulmonary artery (UAPA) is a rare entity that is defined as the complete absence of the intrapericardial segment of 1 of the branch PAs [1]. UAPA may be associated with other congenital heart diseases [2]. The extrapericardial segments of PAs arise from lung buds, whereas the intrapericardial segments of PAs originate from the proximal portion of the sixth aortic arch [3]. It is hypothesized that an absent PA is caused by the involution of the proximal sixth aortic arch and persistence of the connection between the intrapulmonary PA and the distal aortic arch [4]. The surgical treatment options for UAPA include a single- or double-staged repair, such as creation of a systemic-to-pulmonary artery shunt, direct anastomosis of the affected PA to the main pulmonary artery (MPA), interposition of a tubular graft with autologous pericardium or prosthetic material, and semiautologous repair with an MPA flap [5–7]. We present a unique technique by which the discontinuity in the intrapericardial segment of the right PA (RPA) is repaired with the interposition of the autologous PA autograft obtained from the contralateral site.
(Ann Thorac Surg 2015;99:1467–9) Ó 2015 by The Society of Thoracic Surgeons
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HOW TO DO IT BILAL ET AL PULMONARY AUTOGRAFT FOR UAPA
Ann Thorac Surg 2015;99:1467–9
FEATURE ARTICLES
Fig 2. The technique. (A) Segment in red is future pulmonary autograft that will provide continuity between main pulmonary artery (MPA) and right pulmonary artery (RPA). (B) Autograft segment is resected and turned 180 degrees to use its left-sided curve for contralateral side. (C) Inset figures demonstrate surgical technique for constitution of pulmonary bifurcation. (D) Procedure is completed.
aorta were 85/10 mm Hg, 61/17 mm Hg, and 87/46 mm Hg, respectively. The patient was operated on electively. The ascending aorta, MPA, and left PA (LPA) were extensively mobilized. The extrapericardial segment of the RPA was exposed at the right hilum. The aortic right pulmonary collateral vessel, which originated from the anterior of the ascending aorta was observed to be occluded. Cardiopulmonary bypass with moderate hypothermia was initiated after the division of the ligamentum arteriosus that was connecting to the proximal LPA. After crossclamping the aorta, cold antegrade blood cardioplegia was administered in intermittent doses applied every 15 minutes. The subpulmonic VSD was closed with a polytetrafluoroethylene patch through a transverse pulmonary arteriotomy, which was performed 3 mm distal to the pulmonary commissures. Afterward, the MPA was transected, and a 2-cm-long PA autograft segment that extended from the main trunk to the left PA was excised. This naturally left-curving autograft was turned 180 degrees around itself horizontally to yield a right-curving tubular conduit. The distal end of this autograft was anastomosed to the extrapericardial RPA in an end-toend fashion at the right hilum. The posterior wall of the LPA was anastomosed to the posterior side of the MPA, and then the proximal part of the autograft was incorporated obliquely to this union of the LPA and the MPA to constitute the neopulmonary bifurcation (Fig 2). Weaning from cardiopulmonary bypass was uneventful. The pressure at the MPA was measured to be 26/9 mm Hg. Postoperative echocardiography did not reveal any residual shunt or gradient. Contrast-enhanced computed tomography, which was performed 1 week after the operation, demonstrated the patent autograft and normal PA branching pattern (Fig 3). The patient is doing well 6 months after the operation.
Comment The surgical options for the treatment of UAPA may be broadly divided into 2 choices. When the extrapericardial
PA segments are not well developed, the traditional approach of palliation with a systemic-to-PA shunt is considered. Although these interventions are lifesaving in some cases, they may result in peripheral PA stenosis and uneven distribution of pulmonary blood flow [7]. Moreover, these palliative procedures usually complicate subsequent corrective interventions in which extensive reconstruction with prosthetic or autologous pericardial patches as well as homografts are needed [7]. When the extrapericardial arteries are well developed, a singlestage reconstruction might be possible. When the gap between the MPA and RPA is short enough, direct anastomosis should be considered. Other surgical options
Fig 3. (A) Postoperative contrast-enhanced computed tomographic scan demonstrates the pulmonary artery (PA) branching pattern after the operation. (aAo ¼ ascending aorta; aG ¼ autograft; LPA ¼ left pulmonary artery; MPA ¼ main pulmonary artery; RPA ¼ right pulmonary artery.)
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believe to be effective in patients with an absence of the intrapericardial RPA. Although this technique provided excellent short-term results in our patient, long-term follow-up is mandatory for observing its growth potential as well as the development of possible anastomotic stenosis at the neopulmonary bifurcation. The authors thank Sabri Cagri Sezgin for illustrations of the surgical technique.
References 1. Bockeria LA, Podzolkov VP, Makhachev OA, et al. Palliative surgical treatment of congenital heart defects associated with unilateral absence of the pulmonary artery. Interact Cardiovasc Thorac Surg 2013;16:286–92. 2. Pool PE, Vogel JH, Blount SG. Congenital unilateral absence of a pulmonary artery. The importance of flow in pulmonary hypertension. Am J Cardiol 1962;10:706–32. 3. Kruzliak P, Syamasundar RP, Novak M, Pechanova O, Kovacova G. Unilateral absence of pulmonary artery: pathophysiology, symptoms, diagnosis and current treatment. Arch Cardiovasc Dis 2013;106:448–54. 4. Welch K, Hanley F, Johnston T, Cailes C, Shah MJ. Isolated unilateral absence of right proximal pulmonary artery: surgical repair and follow-up. Ann Thorac Surg 2005;79: 1399–402. 5. Kucera V, Fiser B, T uma S, Hucin B. Unilateral absence of pulmonary artery: a report on 19 selected clinical cases. Thorac Cardiovasc Surg 1982;30:152–8. 6. El-Hattab AY, Calcaterra D, Parekh KR, Rossi NP, Davis JE, Turek JW. Semiautologous repair for congenital discontinuous right pulmonary artery. Ann Thorac Surg 2013;96: 2230–1. 7. Shanley CJ, Lupinetti FM, Shah NL, Beekman RH 3rd, Crowley DC, Bove EL. Primary unifocalization for the absence of intrapericardial pulmonary arteries in the neonate. J Thorac Cardiovasc Surg 1993;106:237–47.
FEATURE ARTICLES
are interposition of a tubular graft with autologous pericardium or prosthetic material [4]. Most of the surgical procedures just mentioned have the possibility of repeated intervention, especially when tubular prosthetic material is interposed. Although an autologous pericardial tubular graft is a worthy option, it has limited potential to grow. The most important advantage of our technique is the growth potential of the autologous conduit. The diameter of the autograft is very close to the diameter of the RPA that facilitates the distal anastomosis between the autograft and the RPA at the hilum. This autograft segment also has better handling properties because of its natural curve when compared with pericardial tubular grafts. We performed an extensive release of the fibrotic tissue behind the ascending aorta to create room for the pulmonary autograft, and the risk of possible compression by the anteriorly located ascending aorta was diminished. The increased pulmonary blood flow in our patient was mainly related to 2 factors. The single left PA was receiving all the pulmonary blood flow, which was also increased because of the left-to-right intracardiac shunt through the VSD and patent foramen ovale. This increased blood flow in the left PA obviously had an effect on the elongation and dilatation of the vessel. Although this increased diameter of the LPA may be thought to facilitate the implementation of our technique, the z scores for the MPA and LPA were 0.15 and 1.66, respectively. Therefore we did not encounter a significantly dilated LPA but a somewhat elongated one, which made the procedure easier. Nevertheless, we believe that our technique may also be useful in patients with UAPA without associated intracardiac left-to-right shunts. In conclusion, we developed the pulmonary autograft interposition technique for UAPA repair, which we
HOW TO DO IT BILAL ET AL PULMONARY AUTOGRAFT FOR UAPA
Unilateral absence of the pulmonary artery (PA) is a rare congenital abnormality. Although a traditional 2-stage approach with a preceding systemic-to-PA shunt followed by a definitive repair is mandatory in patients with absent extrapericardial pulmonary arteries, more creative solutions are necessary when 1-stage repair is concerned. We present a novel technique for repairing the absent intrapericardial
right pulmonary artery (RPA) with a contralateral PA autograft segment interposition. We believe that this technique using solely autologous tissue is effective in patients in whom the intrapericardial segment of the PAs is absent.
C
RPA at the right hilum was 4 mm (Fig 1). Main and left PA diameters were 10 mm and 7 mm, respectively. The distance between the RPA at the right hilum and the MPA was 2.6 cm. Two separate aortopulmonary collateral vessels were identified between the ascending aorta and the extrapericardial segment of the RPA at the right hilum. Cardiac catheterization was performed for further diagnostic evaluation. The systolic and diastolic pressures measured at the right ventricle, MPA, and ascending
Technique The patient was a 2-month-old boy (body weight, 6 kg). He had symptoms of congestive heart failure. The echocardiographic evaluation revealed a 5-mm subpulmonic ventricular septal defect (VSD), a nonconfluent RPA, a patent ductus arteriosus, a patent foramen ovale, and pulmonary hypertension. Preoperative computed tomographic angiography demonstrated the absence of an intrapericardial RPA, and the largest diameter of the Accepted for publication Dec 16, 2014. Address correspondence to Dr Ozyuksel, Department of Cardiovascular Surgery, Medipol University, TEM Goztepe Cikisi No. 1, Bagcilar, Istanbul, Turkey; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Fig 1. Preoperative contrast-enhanced computed tomographic scan reveals the absence of intrapericardial segment of right pulmonary artery (RPA), which continues at the right hilum (arrow). (aAo ¼ ascending aorta; dAo ¼ descending aorta; LPA ¼ left pulmonary artery; MPA ¼ main pulmonary artery.) 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.12.036
FEATURE ARTICLES
ongenital unilateral absence of a pulmonary artery (UAPA) is a rare entity that is defined as the complete absence of the intrapericardial segment of 1 of the branch PAs [1]. UAPA may be associated with other congenital heart diseases [2]. The extrapericardial segments of PAs arise from lung buds, whereas the intrapericardial segments of PAs originate from the proximal portion of the sixth aortic arch [3]. It is hypothesized that an absent PA is caused by the involution of the proximal sixth aortic arch and persistence of the connection between the intrapulmonary PA and the distal aortic arch [4]. The surgical treatment options for UAPA include a single- or double-staged repair, such as creation of a systemic-to-pulmonary artery shunt, direct anastomosis of the affected PA to the main pulmonary artery (MPA), interposition of a tubular graft with autologous pericardium or prosthetic material, and semiautologous repair with an MPA flap [5–7]. We present a unique technique by which the discontinuity in the intrapericardial segment of the right PA (RPA) is repaired with the interposition of the autologous PA autograft obtained from the contralateral site.
(Ann Thorac Surg 2015;99:1467–9) Ó 2015 by The Society of Thoracic Surgeons
1468
HOW TO DO IT BILAL ET AL PULMONARY AUTOGRAFT FOR UAPA
Ann Thorac Surg 2015;99:1467–9
FEATURE ARTICLES
Fig 2. The technique. (A) Segment in red is future pulmonary autograft that will provide continuity between main pulmonary artery (MPA) and right pulmonary artery (RPA). (B) Autograft segment is resected and turned 180 degrees to use its left-sided curve for contralateral side. (C) Inset figures demonstrate surgical technique for constitution of pulmonary bifurcation. (D) Procedure is completed.
aorta were 85/10 mm Hg, 61/17 mm Hg, and 87/46 mm Hg, respectively. The patient was operated on electively. The ascending aorta, MPA, and left PA (LPA) were extensively mobilized. The extrapericardial segment of the RPA was exposed at the right hilum. The aortic right pulmonary collateral vessel, which originated from the anterior of the ascending aorta was observed to be occluded. Cardiopulmonary bypass with moderate hypothermia was initiated after the division of the ligamentum arteriosus that was connecting to the proximal LPA. After crossclamping the aorta, cold antegrade blood cardioplegia was administered in intermittent doses applied every 15 minutes. The subpulmonic VSD was closed with a polytetrafluoroethylene patch through a transverse pulmonary arteriotomy, which was performed 3 mm distal to the pulmonary commissures. Afterward, the MPA was transected, and a 2-cm-long PA autograft segment that extended from the main trunk to the left PA was excised. This naturally left-curving autograft was turned 180 degrees around itself horizontally to yield a right-curving tubular conduit. The distal end of this autograft was anastomosed to the extrapericardial RPA in an end-toend fashion at the right hilum. The posterior wall of the LPA was anastomosed to the posterior side of the MPA, and then the proximal part of the autograft was incorporated obliquely to this union of the LPA and the MPA to constitute the neopulmonary bifurcation (Fig 2). Weaning from cardiopulmonary bypass was uneventful. The pressure at the MPA was measured to be 26/9 mm Hg. Postoperative echocardiography did not reveal any residual shunt or gradient. Contrast-enhanced computed tomography, which was performed 1 week after the operation, demonstrated the patent autograft and normal PA branching pattern (Fig 3). The patient is doing well 6 months after the operation.
Comment The surgical options for the treatment of UAPA may be broadly divided into 2 choices. When the extrapericardial
PA segments are not well developed, the traditional approach of palliation with a systemic-to-PA shunt is considered. Although these interventions are lifesaving in some cases, they may result in peripheral PA stenosis and uneven distribution of pulmonary blood flow [7]. Moreover, these palliative procedures usually complicate subsequent corrective interventions in which extensive reconstruction with prosthetic or autologous pericardial patches as well as homografts are needed [7]. When the extrapericardial arteries are well developed, a singlestage reconstruction might be possible. When the gap between the MPA and RPA is short enough, direct anastomosis should be considered. Other surgical options
Fig 3. (A) Postoperative contrast-enhanced computed tomographic scan demonstrates the pulmonary artery (PA) branching pattern after the operation. (aAo ¼ ascending aorta; aG ¼ autograft; LPA ¼ left pulmonary artery; MPA ¼ main pulmonary artery; RPA ¼ right pulmonary artery.)
Ann Thorac Surg 2015;99:1467–9
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believe to be effective in patients with an absence of the intrapericardial RPA. Although this technique provided excellent short-term results in our patient, long-term follow-up is mandatory for observing its growth potential as well as the development of possible anastomotic stenosis at the neopulmonary bifurcation. The authors thank Sabri Cagri Sezgin for illustrations of the surgical technique.
References 1. Bockeria LA, Podzolkov VP, Makhachev OA, et al. Palliative surgical treatment of congenital heart defects associated with unilateral absence of the pulmonary artery. Interact Cardiovasc Thorac Surg 2013;16:286–92. 2. Pool PE, Vogel JH, Blount SG. Congenital unilateral absence of a pulmonary artery. The importance of flow in pulmonary hypertension. Am J Cardiol 1962;10:706–32. 3. Kruzliak P, Syamasundar RP, Novak M, Pechanova O, Kovacova G. Unilateral absence of pulmonary artery: pathophysiology, symptoms, diagnosis and current treatment. Arch Cardiovasc Dis 2013;106:448–54. 4. Welch K, Hanley F, Johnston T, Cailes C, Shah MJ. Isolated unilateral absence of right proximal pulmonary artery: surgical repair and follow-up. Ann Thorac Surg 2005;79: 1399–402. 5. Kucera V, Fiser B, T uma S, Hucin B. Unilateral absence of pulmonary artery: a report on 19 selected clinical cases. Thorac Cardiovasc Surg 1982;30:152–8. 6. El-Hattab AY, Calcaterra D, Parekh KR, Rossi NP, Davis JE, Turek JW. Semiautologous repair for congenital discontinuous right pulmonary artery. Ann Thorac Surg 2013;96: 2230–1. 7. Shanley CJ, Lupinetti FM, Shah NL, Beekman RH 3rd, Crowley DC, Bove EL. Primary unifocalization for the absence of intrapericardial pulmonary arteries in the neonate. J Thorac Cardiovasc Surg 1993;106:237–47.
FEATURE ARTICLES
are interposition of a tubular graft with autologous pericardium or prosthetic material [4]. Most of the surgical procedures just mentioned have the possibility of repeated intervention, especially when tubular prosthetic material is interposed. Although an autologous pericardial tubular graft is a worthy option, it has limited potential to grow. The most important advantage of our technique is the growth potential of the autologous conduit. The diameter of the autograft is very close to the diameter of the RPA that facilitates the distal anastomosis between the autograft and the RPA at the hilum. This autograft segment also has better handling properties because of its natural curve when compared with pericardial tubular grafts. We performed an extensive release of the fibrotic tissue behind the ascending aorta to create room for the pulmonary autograft, and the risk of possible compression by the anteriorly located ascending aorta was diminished. The increased pulmonary blood flow in our patient was mainly related to 2 factors. The single left PA was receiving all the pulmonary blood flow, which was also increased because of the left-to-right intracardiac shunt through the VSD and patent foramen ovale. This increased blood flow in the left PA obviously had an effect on the elongation and dilatation of the vessel. Although this increased diameter of the LPA may be thought to facilitate the implementation of our technique, the z scores for the MPA and LPA were 0.15 and 1.66, respectively. Therefore we did not encounter a significantly dilated LPA but a somewhat elongated one, which made the procedure easier. Nevertheless, we believe that our technique may also be useful in patients with UAPA without associated intracardiac left-to-right shunts. In conclusion, we developed the pulmonary autograft interposition technique for UAPA repair, which we
HOW TO DO IT BILAL ET AL PULMONARY AUTOGRAFT FOR UAPA
