Ann Thorac Surg 2014;97:1852–7
Biologic Valved Conduits in Infants To the Editor: The authors of the article “Association of pulmonary conduit type and size with durability in infants and young children” [1] have to be congratulated because they provide useful suggestions to the surgeons involved with the surgical treatment of complex congenital heart defects requiring the implantation of valved conduits. Both the article and the following discussion failed to take into consideration several practical points aiming at reducing the most frequent and important potential complication in the medium and long-term results: obstruction with small conduits, particularly in correspondence with the distal anastomosis [1]. The following surgical hints, all previously reported, should have deserved a space in the section “Surgeon-Modifiable Factors”: (1) the tailoring of the distal end of the conduit, (2) the incision on the pulmonary artery, and (3) the anastomosis technique avoiding pursestring running sutures. Tailoring of the distal end of the conduit: A computational fluid dynamic study compared the conventional “circular” type of anastomosis, obtained by cutting the distal end of the conduit transversally, with an “elliptical” type of anastomosis, obtained after oblique distal cutting of the conduit [2]. The study demonstrated more homogeneous velocity, pressure, and shear stress distributions with the “elliptical” rather than the conventional “circular” type of anastomosis at the level of the pulmonary artery bifurcation because of the larger crosssectional area obtained by cutting the distal conduit obliquely [2]. Incision on the pulmonary artery: The incision on the pulmonary bifurcation, as in repair of tetralogy of Fallot, should be extended toward the anterior aspect of the left pulmonary artery to enlarge as much as possible the size and cross-sectional area of the distal anastomosis [3]. Anastomosis technique avoiding pursestring running sutures: Continuous running sutures should be strictly avoided in correspondence with the distal anastomosis, particularly with small conduits, to reduce the risk of further reducing the crosssectional area because of the pursestring effect [3]. This can be easily achieved by performing several short running sutures with four or five interruptions along the entire circumference of the distal anastomosis [3]. With the strict application of these combined surgical details, associated with a reasonable oversize of the conduit in relationship to the age and body weight of the patients, the risk of stenosis at the level of the distal anastomosis was substantially reduced, and acceptable medium-term and long-term results were achieved even in infants [4].
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References 1. Poynter JA, Eghtesady P, McCrindle BW, et al. Association of pulmonary conduit type and size with durability in infants and young children. Ann Thorac Surg 2013;96:1695–702. 2. Corno AF, Mickaily-Huber ES. Comparative computational fluid dynamic study of two distal Contegra conduit anastomoses. Interact Cardiovasc Thorac Surg 2008;7:1–5. 3. Corno AF, Qanadli SD, Sekarski N, et al. Bovine valved xenograft in pulmonary position: medium-term follow-up with excellent hemodynamics and freedom from calcifications. Ann Thorac Surg 2004;78:1382–8. 4. Prior N, Alphonso N, Arnold P, et al. Bovine jugular vein valved conduit: up to 10 years follow-up. J Thorac Cardiovasc Surg 2011;141:983–7.
Pericardial Coverage of the Bronchial Stump To the Editor: I read with interest the article by de Perrot, “The use of posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy” [1]. His approach uses the well-proven technique of covering the bronchial stump with a small posterior flap of pericardium, which, as stated, “has the advantage of being easy to perform and requiring limited time and dissection.” My question to the author is why does he limit this approach to extrapleural
Antonio F. Corno, FRCS (Glasgow), FETCS Department of Surgery University Sains Malaysia School of Medical Sciences, Health Campus 16150 Kubang Kerian, Kelantan Malaysia e-mail: [email protected] Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Fig. 1. Coverage of the left bronchial stump with a small posterior pericardial flap. (Reprinted from Robicsek F, et al. J Thorac Cardiovasc Surg 1969;4:532–4 [2].) 0003-4975/$36.00
MISCELLANEOUS
5. Pattakos G, Koch CG, Brizzio ME, et al. Outcome of patients who refuse transfusion after cardiac surgery: a natural experiment with severe blood conservation. Arch Intern Med 2012;172:1154–60. 6. Loor G, Rajeswaran J, Li L, et al. The least of 3 evils: exposure to red blood cell transfusion, anemia, or both? J Thorac Cardiovasc Surg 2013;146:1480–7.
CORRESPONDENCE
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CORRESPONDENCE
pneumonectomies; especially, why only on the right side? The maneuver of bronchial coverage with the posterior pericardial flap could be performed in the course of intrapleural pneumonectomies as well and on the left side, even more easily than on the right [2] (Fig 1). Francis Robicsek, MD, PhD Department of Thoracic and Cardiovascular Surgery Carolinas Medical Center 1001 Blythe Blvd, Ste 300 Charlotte, NC 28203 e-mail: [email protected]
References 1. de Perrot M. Use of the posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy. Ann Thorac Surg 2013;96:706–8. 2. Robicsek F, Sanger P, Daugherty HK. A modification of the technique of left pneumonectomy. J Thorac Cardiovas Surg 1969;4:543–4.
Reply To the Editor: Thank you for your comments and interest [1] regarding my article [2]. This technique can be used for right and left pneumonectomy as well as extrapleural pneumonectomy. However, the use of the posterior pericardium to cover the right bronchial stump has not been described in detail previously. More options are usually available to cover the bronchial stump after right pneumonectomy than after extrapleural pneumonectomy. Hence, the use of the posterior pericardium is particularly helpful for extrapleural pneumonectomy.
Ann Thorac Surg 2014;97:1852–7
that the higher total pulmonary vascular resistance in the Fallot group was due to a larger amount of stroke volume (secondary to pulmonary regurgitation). Pulmonary arterial compliance was also found to be in correlation with right ventricular end-diastolic volume in the Fallot group, but our opinion is that pulmonary arterial compliance could not be correlated with right ventricular end-diastolic volume. Because right ventricular volume was determined by regurgitation in the Fallot group (according to the results in the article, left ventricular volume should have increased in all of the cases with supracoronary aortic replacement because of lower compliance). The homogenous distribution and standardization of the Fallot group was disturbed by the diversity of interventions and medications (transannular patch, percutaneous valvuloplasty, shunts). What we get as a consequence from this valuable study is that right ventricular preload increases caused by pulmonary regurgitation, and the right ventricle dilates (in Table 2 of the article, right ventricle dilated 1.64 times its initial dimensions) resulting in increased pulmonary arterial stiffness secondary to increased right ventricular stroke volume. For instance, the incidence of peripheral arterial aneuryms increases in case of aortic regurgitation (aneurysm develops secondary to an increase in stroke volume). We think that the measurements of compliance, impedance, and right ventricular end-diastolic volume in cases of tetralogy of Fallot with no pulmonary regurgitation would support our argument. Habib Cakir, MD Mert Kestelli, MD Ismail Yurekli, MD Koksal Donmez, MD Department of Cardiovascular Surgery Katip Celebi University Izmir Atat€ urk Training and Research Hospital Karabaglar 35360 Izmir, Turkey e-mail: [email protected]
Marc de Perrot, MD, MS Division of Thoracic Surgery Toronto General Hospital 200 Elizabeth St Toronto, Ontario M5G 2C4 Canada e-mail: [email protected]
References 1. Robicsek F. Pericardial coverage of the bronchial stump (letter). Ann Thorac Surg 2014;97:1853–4. 2. de Perrot M. Use of the posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy. Ann Thorac Surg 2013;96:706–8.
Pulmonary Arterial Stiffness, Compliance, and Impedance To the Editor: MISCELLANEOUS
We congratulate Inuzuka and colleagues [1] on the success of their surgical procedure and excellent study recently reported online in The Annals of Thoracic Surgery. We would also like to highlight some issues. Usually, systole is shorter than diastole. Therefore, systolic pressure was measured higher in the tetralogy of Fallot group than the diastolic pressure in Table 2 of the article. This demonstrates that the kinetic energy within the pulmonary artery of the Fallot group was lower. We think Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Reference 1. Inuzuka R, Seki M, Sugimoto M, Saiki H, Masutani S, Senzaki H. Pulmonary arterial wall stiffness and its impact on right ventricular afterload in patients with repaired tetralogy of Fallot. Ann Thorac Surg 2013;96:1435–41.
Reply To the Editor: We thank Cakir and colleagues [1] for their thoughtful comments regarding our study [2]. We agree with them that pulmonary regurgitation (PR) is a major cause of right ventricular (RV) dilation in patients with tetralogy of Fallot (TOF). Because of the cross-sectional observational nature of our study, we cannot exclude the possibility that the correlation between pulmonary arterial compliance and RV end-diastolic volume is confounded by the presence of PR, as they have suggested. However, a significant correlation between RV end-diastolic volume and pulmonary arterial compliance was observed among patients without significant PR, as shown in Figure 3 in our original study [2]. Moreover, pulmonary arterial compliance continued to be significantly related to RV end-diastolic volume even after adjusting for the presence of PR (Table 3 [2]). Therefore, we speculate that the pathologic increase of systolic and diastolic dimensions is a manifestation of RV dysfunction and occurs as a direct result of increased afterload independently of PR augmentation. 0003-4975/$36.00
Biologic Valved Conduits in Infants To the Editor: The authors of the article “Association of pulmonary conduit type and size with durability in infants and young children” [1] have to be congratulated because they provide useful suggestions to the surgeons involved with the surgical treatment of complex congenital heart defects requiring the implantation of valved conduits. Both the article and the following discussion failed to take into consideration several practical points aiming at reducing the most frequent and important potential complication in the medium and long-term results: obstruction with small conduits, particularly in correspondence with the distal anastomosis [1]. The following surgical hints, all previously reported, should have deserved a space in the section “Surgeon-Modifiable Factors”: (1) the tailoring of the distal end of the conduit, (2) the incision on the pulmonary artery, and (3) the anastomosis technique avoiding pursestring running sutures. Tailoring of the distal end of the conduit: A computational fluid dynamic study compared the conventional “circular” type of anastomosis, obtained by cutting the distal end of the conduit transversally, with an “elliptical” type of anastomosis, obtained after oblique distal cutting of the conduit [2]. The study demonstrated more homogeneous velocity, pressure, and shear stress distributions with the “elliptical” rather than the conventional “circular” type of anastomosis at the level of the pulmonary artery bifurcation because of the larger crosssectional area obtained by cutting the distal conduit obliquely [2]. Incision on the pulmonary artery: The incision on the pulmonary bifurcation, as in repair of tetralogy of Fallot, should be extended toward the anterior aspect of the left pulmonary artery to enlarge as much as possible the size and cross-sectional area of the distal anastomosis [3]. Anastomosis technique avoiding pursestring running sutures: Continuous running sutures should be strictly avoided in correspondence with the distal anastomosis, particularly with small conduits, to reduce the risk of further reducing the crosssectional area because of the pursestring effect [3]. This can be easily achieved by performing several short running sutures with four or five interruptions along the entire circumference of the distal anastomosis [3]. With the strict application of these combined surgical details, associated with a reasonable oversize of the conduit in relationship to the age and body weight of the patients, the risk of stenosis at the level of the distal anastomosis was substantially reduced, and acceptable medium-term and long-term results were achieved even in infants [4].
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References 1. Poynter JA, Eghtesady P, McCrindle BW, et al. Association of pulmonary conduit type and size with durability in infants and young children. Ann Thorac Surg 2013;96:1695–702. 2. Corno AF, Mickaily-Huber ES. Comparative computational fluid dynamic study of two distal Contegra conduit anastomoses. Interact Cardiovasc Thorac Surg 2008;7:1–5. 3. Corno AF, Qanadli SD, Sekarski N, et al. Bovine valved xenograft in pulmonary position: medium-term follow-up with excellent hemodynamics and freedom from calcifications. Ann Thorac Surg 2004;78:1382–8. 4. Prior N, Alphonso N, Arnold P, et al. Bovine jugular vein valved conduit: up to 10 years follow-up. J Thorac Cardiovasc Surg 2011;141:983–7.
Pericardial Coverage of the Bronchial Stump To the Editor: I read with interest the article by de Perrot, “The use of posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy” [1]. His approach uses the well-proven technique of covering the bronchial stump with a small posterior flap of pericardium, which, as stated, “has the advantage of being easy to perform and requiring limited time and dissection.” My question to the author is why does he limit this approach to extrapleural
Antonio F. Corno, FRCS (Glasgow), FETCS Department of Surgery University Sains Malaysia School of Medical Sciences, Health Campus 16150 Kubang Kerian, Kelantan Malaysia e-mail: [email protected] Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Fig. 1. Coverage of the left bronchial stump with a small posterior pericardial flap. (Reprinted from Robicsek F, et al. J Thorac Cardiovasc Surg 1969;4:532–4 [2].) 0003-4975/$36.00
MISCELLANEOUS
5. Pattakos G, Koch CG, Brizzio ME, et al. Outcome of patients who refuse transfusion after cardiac surgery: a natural experiment with severe blood conservation. Arch Intern Med 2012;172:1154–60. 6. Loor G, Rajeswaran J, Li L, et al. The least of 3 evils: exposure to red blood cell transfusion, anemia, or both? J Thorac Cardiovasc Surg 2013;146:1480–7.
CORRESPONDENCE
1854
CORRESPONDENCE
pneumonectomies; especially, why only on the right side? The maneuver of bronchial coverage with the posterior pericardial flap could be performed in the course of intrapleural pneumonectomies as well and on the left side, even more easily than on the right [2] (Fig 1). Francis Robicsek, MD, PhD Department of Thoracic and Cardiovascular Surgery Carolinas Medical Center 1001 Blythe Blvd, Ste 300 Charlotte, NC 28203 e-mail: [email protected]
References 1. de Perrot M. Use of the posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy. Ann Thorac Surg 2013;96:706–8. 2. Robicsek F, Sanger P, Daugherty HK. A modification of the technique of left pneumonectomy. J Thorac Cardiovas Surg 1969;4:543–4.
Reply To the Editor: Thank you for your comments and interest [1] regarding my article [2]. This technique can be used for right and left pneumonectomy as well as extrapleural pneumonectomy. However, the use of the posterior pericardium to cover the right bronchial stump has not been described in detail previously. More options are usually available to cover the bronchial stump after right pneumonectomy than after extrapleural pneumonectomy. Hence, the use of the posterior pericardium is particularly helpful for extrapleural pneumonectomy.
Ann Thorac Surg 2014;97:1852–7
that the higher total pulmonary vascular resistance in the Fallot group was due to a larger amount of stroke volume (secondary to pulmonary regurgitation). Pulmonary arterial compliance was also found to be in correlation with right ventricular end-diastolic volume in the Fallot group, but our opinion is that pulmonary arterial compliance could not be correlated with right ventricular end-diastolic volume. Because right ventricular volume was determined by regurgitation in the Fallot group (according to the results in the article, left ventricular volume should have increased in all of the cases with supracoronary aortic replacement because of lower compliance). The homogenous distribution and standardization of the Fallot group was disturbed by the diversity of interventions and medications (transannular patch, percutaneous valvuloplasty, shunts). What we get as a consequence from this valuable study is that right ventricular preload increases caused by pulmonary regurgitation, and the right ventricle dilates (in Table 2 of the article, right ventricle dilated 1.64 times its initial dimensions) resulting in increased pulmonary arterial stiffness secondary to increased right ventricular stroke volume. For instance, the incidence of peripheral arterial aneuryms increases in case of aortic regurgitation (aneurysm develops secondary to an increase in stroke volume). We think that the measurements of compliance, impedance, and right ventricular end-diastolic volume in cases of tetralogy of Fallot with no pulmonary regurgitation would support our argument. Habib Cakir, MD Mert Kestelli, MD Ismail Yurekli, MD Koksal Donmez, MD Department of Cardiovascular Surgery Katip Celebi University Izmir Atat€ urk Training and Research Hospital Karabaglar 35360 Izmir, Turkey e-mail: [email protected]
Marc de Perrot, MD, MS Division of Thoracic Surgery Toronto General Hospital 200 Elizabeth St Toronto, Ontario M5G 2C4 Canada e-mail: [email protected]
References 1. Robicsek F. Pericardial coverage of the bronchial stump (letter). Ann Thorac Surg 2014;97:1853–4. 2. de Perrot M. Use of the posterior pericardium to cover the bronchial stump after right extrapleural pneumonectomy. Ann Thorac Surg 2013;96:706–8.
Pulmonary Arterial Stiffness, Compliance, and Impedance To the Editor: MISCELLANEOUS
We congratulate Inuzuka and colleagues [1] on the success of their surgical procedure and excellent study recently reported online in The Annals of Thoracic Surgery. We would also like to highlight some issues. Usually, systole is shorter than diastole. Therefore, systolic pressure was measured higher in the tetralogy of Fallot group than the diastolic pressure in Table 2 of the article. This demonstrates that the kinetic energy within the pulmonary artery of the Fallot group was lower. We think Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
Reference 1. Inuzuka R, Seki M, Sugimoto M, Saiki H, Masutani S, Senzaki H. Pulmonary arterial wall stiffness and its impact on right ventricular afterload in patients with repaired tetralogy of Fallot. Ann Thorac Surg 2013;96:1435–41.
Reply To the Editor: We thank Cakir and colleagues [1] for their thoughtful comments regarding our study [2]. We agree with them that pulmonary regurgitation (PR) is a major cause of right ventricular (RV) dilation in patients with tetralogy of Fallot (TOF). Because of the cross-sectional observational nature of our study, we cannot exclude the possibility that the correlation between pulmonary arterial compliance and RV end-diastolic volume is confounded by the presence of PR, as they have suggested. However, a significant correlation between RV end-diastolic volume and pulmonary arterial compliance was observed among patients without significant PR, as shown in Figure 3 in our original study [2]. Moreover, pulmonary arterial compliance continued to be significantly related to RV end-diastolic volume even after adjusting for the presence of PR (Table 3 [2]). Therefore, we speculate that the pathologic increase of systolic and diastolic dimensions is a manifestation of RV dysfunction and occurs as a direct result of increased afterload independently of PR augmentation. 0003-4975/$36.00
