The optimal Fontan operation: Lateral tunnel or extracardiac conduit?
2020; Elsevier BV; Volume: 162; Issue: 6 Linguagem: Inglês
10.1016/j.jtcvs.2020.11.179
ISSN1097-685X
Autores Tópico(s)Cardiac Arrhythmias and Treatments
ResumoCentral MessageDespite decades of follow-up, the optimal Fontan operation remains elusive. Given the variability in published outcomes, a randomized control trial might help identify the optimal technique.See Commentaries on pages 1835 and 1836. Despite decades of follow-up, the optimal Fontan operation remains elusive. Given the variability in published outcomes, a randomized control trial might help identify the optimal technique. See Commentaries on pages 1835 and 1836. The most widely adopted variations of the Fontan procedure are the extracardiac conduit (ECC) and the lateral tunnel (LT). Over the last decade, there seemed to have been a shift in our practice, with the majority of the Fontan operations being the ECC, on the premise of the simplicity of this procedure and the expectation that it can better prevent the late occurrence of arrhythmias. A recent article in the Journal by a team from Boston demonstrated that in their hands, the ECC was associated with worse early outcomes compared with the LT.1Weixler V.H.M. Zurakowski D. Kheir J. Guariento A. Kaza A.K. Baird C.W. et al.Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit.J Thorac Cardiovasc Surg. 2020; 159: 1480-1491.e2Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar We reviewed the existing literature to identify whether one of these techniques is superior to the other. Here we performed a search of the PubMed database to identify studies with early and late outcomes. Inclusion criteria included (1) >200 patients, (2) published from 2005 onward, and (3) >50% with LT and ECC. Fourteen articles were identified for early outcomes, and 11 were identified for late outcomes (Tables 1 and 2).Table 1Early outcomes of contemporary techniquesAuthorsDatesNumberEarly mortality, %ComparisonCommentWeixler et al, 20201Weixler V.H.M. Zurakowski D. Kheir J. Guariento A. Kaza A.K. Baird C.W. et al.Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit.J Thorac Cardiovasc Surg. 2020; 159: 1480-1491.e2Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar2000-2017Total: 801LT: 638ECC: 183Overall: 1.0LT: 0.5ECC: 3.1Propensity-score matched: age, fenestration, heterotaxy, ventricular dominance and concomitant proceduresP < .01 in mortality in favor of LT.Mery et al, 20192Mery C.M. De León L.E. Trujillo-Diaz D. Ocampo E.C. Dickerson H.A. Zhu H. et al.Contemporary outcomes of the Fontan operation: a large single-institution cohort.Ann Thorac Surg. 2019; 108: 1439-1446Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar1995-2016Total: 610LT: 147ECC: 463Overall: 0.5Demographics unavailable for Fontan-type comparison. Fontan type not considered a risk factor.No difference reported in mortality or morbidity.Downing et al, 20173Downing T.E. Allen K.Y. Glatz A.C. Rogers L.S. Ravishankar C. Rychik J. et al.Long-term survival after the Fontan operation: twenty years of experience at a single center.J Thorac Cardiovasc Surg. 2017; 154: 243-253.e2Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar1992-2009Total: 773LT: 409ECC: 364Overall: 3.5LT: NRECC: NRDemographics unavailable for Fontan-type comparison. Fontan type included in multivariable risk factor analysis.No difference reported in mortality.Ono et al, 20164Ono M. Kasnar-Samprec J. Hager A. Cleuziou J. Burri M. Langenbach C. et al.Clinical outcome following total cavopulmonary connection: a 20-year single-centre experience.Eur J Cardiothorac Surg. 2016; 50: 632-641Crossref PubMed Scopus (67) Google Scholar1994-2015Total: 434LT: 50ECC: 384Overall: 2LT: 6ECC: 2ECC cohort had more right ventricular dominance, HLHS, and heterotaxy, and fewer concomitant procedures and fenestrations at time of Fontan.P = .02 in mortality in favor of ECC.Nakano et al, 20155Nakano T. Kado H. Tatewaki H. Hinokiyama K. Oda S. Ushinohama H. et al.Results of extracardiac conduit total cavopulmonary connection in 500 patients.Eur J Cardiothorac Surg. 2015; 48: 825-832Crossref PubMed Scopus (74) Google Scholar1994-2014Total: 500LT: 0ECC: 500Overall: 0.4LT: N/AECC: 0.4Only ECCOnly looked at ECC.Iyengar et al, 20146Iyengar A.J. Winlaw D.S. Galati J.C. Celermajer D.S. Wheaton G.R. Gentles T.L. et al.Trends in Fontan surgery and risk factors for early adverse outcomes after Fontan surgery: the Australia and New Zealand Fontan registry experience.J Thorac Cardiovasc Surg. 2014; 148: 566-575Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar1975-2010Total: 1071LT: 296ECC: 536Overall: 3.5 (including AP Fontan)LT: 2.0 (6/269)ECC: 1.3 (7/536)Multivariable models accounting for common risk factors performed (including ventricular dominance and heterotaxy) to compare LT and ECC patients.No difference reported in mortality.Rogers et al, 20127Rogers L.S. Glatz A.C. Ravishankar C. Spray T.L. Nicolson S.C. Rychik J. et al.18 years of the Fontan operation at a single institution: results from 771 consecutive patients.J Am Coll Cardiol. 2012; 60: 1018-1025Crossref PubMed Scopus (133) Google Scholar1992-2009Total: 771LT: 409ECC: 362Overall: 3.5LT: NRECC: NRDemographics unavailable for Fontan-type comparison. Multivariable analysis performed including all preoperative risk factors.P = .196; no difference in mortality. ECC associated with prolonged pleural drainage and hospital stay (due to longer support times).Stewart et al, 20128Stewart R.D. Pasquali S.K. Jacobs J.P. Benjamin D.K. Jaggers J. Cheng J. et al.Contemporary Fontan operation: association between early outcome and type of cavopulmonary connection.Ann Thorac Surg. 2012; 93 (discussion 1261): 1254-1260Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar2000-2009Total: 2747LT: 1017ECC: 1730Overall: 1.6LT: 0.9ECC: 2.1Unadjusted and multivariable analyses (age, weight, and all preoperative risk factors) performed, including logistic and linear regressionsP = .02 in mortality in favor of LT.Robbers-Visser et al, 20109Robbers-Visser D. Miedema M. Nijveld A. Boersma E. Bogers A.J. Haas F. et al.Results of staged total cavopulmonary connection for functionally univentricular hearts; comparison of intra-atrial lateral tunnel and extracardiac conduit.Eur J Cardiothorac Surg. 2010; 37: 934-941Crossref PubMed Scopus (57) Google Scholar1988-2008Total: 209LT: 102ECC: 107Overall: 4LT: 3.9ECC: 4.7Preoperative risk factors accounted for in multivariable analysis. HLHS and tricuspid atresia more common in ECC group.No difference reported in mortality or morbidity.Brown et al, 201010Brown J.W. Ruzmetov M. Deschner B.W. Rodefeld M.D. Turrentine M.W. Lateral tunnel Fontan in the current era: is it still a good option?.Ann Thorac Surg. 2010; 89 (discussion 562-3): 556-562Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar1992-2008Total: 280LT: 220ECC: 0Overall: 0.5LT: 0.5ECC: N/AOnly LTOnly looked at LT.Salazar et al, 201011Salazar J.D. Zafar F. Siddiqui K. Coleman R.D. Morales D.L.S. Heinle J.S. et al.Fenestration during Fontan palliation: now the exception instead of the rule.J Thorac Cardiovasc Surg. 2010; 140: 129-136Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar2002-2008Total: 226LT: 69ECC: 157Overall: 1.3LT: 1.4ECC: 1.3Full demographics unavailable for Fontan-type comparison. Risk factors included in multivariable analysis. No difference in concomitant procedures at the time of Fontan.No difference in mortality.LT associated with longer ICU stay (P = .022) and total hospital stay (P = .017).Tweddell et al, 200912Tweddell J.S. Nersesian M. Mussatto K.A. Nugent M. Simpson P. Mitchell M.E. et al.Fontan palliation in the modern era: factors impacting mortality and morbidity.Ann Thorac Surg. 2009; 88: 1291-1299Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar1994-2007Total: 256LT: 81ECC: 175Overall: 2LT: NRECC: NRMultivariable analysis performed including preoperative risk factors (excluding heterotaxy).No difference reported in mortality or morbidity.Kim et al, 200813Kim S.J. Kim W.H. Lim H.G. Lee J.Y. Outcome of 200 patients after an extracardiac Fontan procedure.J Thorac Cardiovasc Surg. 2008; 136: 108-116Abstract Full Text Full Text PDF PubMed Scopus (145) Google Scholar1996-2006Total: 200LT: 0ECC: 200Overall: 3LT: N/AECC: 3Only LTOnly looked at ECC.Hirsch et al, 200814Hirsch J.C. Goldberg C. Bove E.L. Salehian S. Lee T. Ohye R.G. et al.Fontan operation in the current era: a 15-year single institution experience.Ann Surg. 2008; 248: 402-410Crossref PubMed Scopus (8) Google Scholar1992-2007Total: 636LT: 585ECC: 51Overall: 4LT: NRECC: NRECC was performed in patients with anatomy not amenable to LT technique. Group comparison is not accurate due to selection bias.P = .02 in mortality in favor of LT. ECC associated with prolonged effusions (P = .01) and atrial arrhythmias (P = .02).Complicated by minimal fenestration use in ECC (35%) vs 100% in LT.LT, Lateral tunnel; ECC, extracardiac conduit; NR, not reported; HLHS, hypoplastic left heart syndrome; N/A, not applicable; AP, atriopulmonary; ICU, intensive care unit. Open table in a new tab Table 2Late outcomes of contemporary techniquesAuthorsDatesnFollow-up, y (median)Survival, %ComparisonCommentWeixler et al, 20201Weixler V.H.M. Zurakowski D. Kheir J. Guariento A. Kaza A.K. Baird C.W. et al.Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit.J Thorac Cardiovasc Surg. 2020; 159: 1480-1491.e2Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar2000-2017Total: 801LT: 638ECC: 1834.85 y: LT, 96.4 vs ECC, 92.010 y: LT, 94.5 vs ECC, 91.420 y: LT, 93.9 vs ECC, 90.8Propensity-score matched: age, fenestration, heterotaxy, ventricular dominance, and concomitant proceduresImproved survival in LT group (HR, 2.7; P < .05). Better freedom from failure in LT group (P = .02). Pleural effusions more common in ECC group (P = .01).Deshaies et al, 201915Deshaies C. Hamilton R.M. Shohoudi A. Trottier H. Poirier N. Aboulhosn J. et al.Thromboembolic risk after atriopulmonary, lateral tunnel, and extracardiac conduit Fontan surgery.J Am Coll Cardiol. 2019; 74: 1071-1081Crossref PubMed Scopus (28) Google Scholar1974-2012Total: 522LT: 218ECC: 19211.65 y: 98.310 y: 94.720 y: 78.9Demographics comparison between LT and ECC unavailable. Multivariable analysis of thromboembolic risk performed between LT and ECC (including arrhythmias and thromboprophylaxis).Includes AP Fontan. No difference reported in survival or arrhythmias. Lower rate of thromboembolic events in ECC group compared with LT (HR, 0.34; 95% CI, 0.13-0.91).Mery et al, 20192Mery C.M. De León L.E. Trujillo-Diaz D. Ocampo E.C. Dickerson H.A. Zhu H. et al.Contemporary outcomes of the Fontan operation: a large single-institution cohort.Ann Thorac Surg. 2019; 108: 1439-1446Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar1995-2016Total: 610LT: 147ECC: 4636.85 y: 9710 y: 9415 y: 92Demographics unavailable for Fontan-type comparison. Fontan type not considered a risk factor.No difference reported in survival or failure. Higher incidence of arrhythmia in the LT group compared with the ECC group (P = .002).Downing et al, 20173Downing T.E. Allen K.Y. Glatz A.C. Rogers L.S. Ravishankar C. Rychik J. et al.Long-term survival after the Fontan operation: twenty years of experience at a single center.J Thorac Cardiovasc Surg. 2017; 154: 243-253.e2Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar1992-2009Total: 773LT: 409ECC: 364910 y: 90 (95% CI, 88-92)20 y: 74 (95% CI, 67-80)Demographics unavailable for Fontan-type comparison. Fontan type included in multivariable risk factor analysis.Survival with intact Fontan circulation. Fontan type did not impact late outcomes (survival or failure).Iyengar et al, 20146Iyengar A.J. Winlaw D.S. Galati J.C. Celermajer D.S. Wheaton G.R. Gentles T.L. et al.Trends in Fontan surgery and risk factors for early adverse outcomes after Fontan surgery: the Australia and New Zealand Fontan registry experience.J Thorac Cardiovasc Surg. 2014; 148: 566-575Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar1975-2010Total: 1006LT: 271ECC: 532NR15 y: 93 (95% CI, 90-95)20 y: 90 (95% CI, 86-93)25 y: 83 (95% CI, 75-89)Multivariable models accounting for common risk factors (including ventricular dominance and heterotaxy) performed to compare LT and ECC patients.No difference reported in survival between LT and ECCHigher rate of SVT in LT (HR, 3.1; P = .019). No reported difference in failure or other adverse events.Nakano et al, 20155Nakano T. Kado H. Tatewaki H. Hinokiyama K. Oda S. Ushinohama H. et al.Results of extracardiac conduit total cavopulmonary connection in 500 patients.Eur J Cardiothorac Surg. 2015; 48: 825-832Crossref PubMed Scopus (74) Google Scholar1994-2014Total: 500LT: 0ECC: 500715 y: 93Only ECCOnly ECC in the study.Ono et al, 20164Ono M. Kasnar-Samprec J. Hager A. Cleuziou J. Burri M. Langenbach C. et al.Clinical outcome following total cavopulmonary connection: a 20-year single-centre experience.Eur J Cardiothorac Surg. 2016; 50: 632-641Crossref PubMed Scopus (67) Google Scholar1994-2015Total: 434LT: 50ECC: 3846.615 y: 92.3ECC cohort had more right ventricular dominance, HLHS, heterotaxy, and fewer concomitant procedures and fenestrations at time of Fontan.No reported difference in survival. Predicted % of peak VO2 higher in ECC group (P < .001)Balaji et al, 201416Balaji S. Daga A. Bradley D.J. Etheridge S.P. Law I.H. Batra A.J. et al.An international multicenter study comparing arrhythmia prevalence between the intracardiac lateral tunnel and the extracardiac conduit type of Fontan operations.J Thorac Cardiovasc Surg. 2014; 148: 576-581Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar1998-2008Total: 1271LT: 602ECC: 6699.2NRUnivariable and multivariable analysis performed for ECC and LT comparison. ECC had more left ventricular dominance and older age at Fontan on univariable analysis.Higher rate of early postoperative bradyarrhythmia in ECC group (P < .001)No difference at late follow-up between LT and ECC.Robbers-Visser et al, 20109Robbers-Visser D. Miedema M. Nijveld A. Boersma E. Bogers A.J. Haas F. et al.Results of staged total cavopulmonary connection for functionally univentricular hearts; comparison of intra-atrial lateral tunnel and extracardiac conduit.Eur J Cardiothorac Surg. 2010; 37: 934-941Crossref PubMed Scopus (57) Google Scholar1988-2008Total: 209LT: 102ECC: 1074.3Freedom from failure (mortality and failure)3 y: LT, 85 vs ECC, 886 y: LT, 83 vs ECC, 79Preoperative risk factors accounted for in multivariable analysis. HLHS and tricuspid atresia more common in ECC group.No difference reported in survival/freedom from failure (P = .93). Higher rate of arrhythmia in the LT group on log-rank analysis (P = .022).Hirsch et al, 200814Hirsch J.C. Goldberg C. Bove E.L. Salehian S. Lee T. Ohye R.G. et al.Fontan operation in the current era: a 15-year single institution experience.Ann Surg. 2008; 248: 402-410Crossref PubMed Scopus (8) Google Scholar1992-2007Total: 636LT: 585ECC: 5145 y: 9510 y: 9314 y: 91ECC was performed in patients with anatomy not amenable to LT technique. Group comparison is inaccurate due to selection bias.Unable to compare difference due to patient selection bias.Mitchell et al, 200617Mitchell M.E. Ittenbach R.F. Gaynor J.W. Wernovsky G. Nicolson S. Spray T.L. Intermediate outcomes after the Fontan procedure in the current era.J Thorac Cardiovasc Surg. 2006; 131: 172-180Abstract Full Text Full Text PDF PubMed Scopus (101) Google Scholar1992-1999Total: 322LT: 262ECC: 488.3Freedom from death and transplantation5 y: 94.9 (95% CI, 91.6-97.0)8 y: 93.9 (95% CI, 90.1-96.2)Comparison of demographics between LT and ECC unavailable. Univariable and multivariable analyses performed. No difference in preoperative or operative variables between group outcomes.No difference reported in survival/freedom from failure or hospitalization (P = .062).LT, Lateral tunnel; ECC, extracardiac conduit; HR, hazard ratio; AP, atriopulmonary; CI, confidence interval; SVT, supraventricular tachycardia; HLHS, hypoplastic left heart syndrome; VO2, oxygen consumption; NR, not reported. Open table in a new tab LT, Lateral tunnel; ECC, extracardiac conduit; NR, not reported; HLHS, hypoplastic left heart syndrome; N/A, not applicable; AP, atriopulmonary; ICU, intensive care unit. LT, Lateral tunnel; ECC, extracardiac conduit; HR, hazard ratio; AP, atriopulmonary; CI, confidence interval; SVT, supraventricular tachycardia; HLHS, hypoplastic left heart syndrome; VO2, oxygen consumption; NR, not reported. First reported by Puga and colleagues18Puga F.J. Chiavarelli M. Hagler D.J. Modifications of the Fontan operation applicable to patients with left atrioventricular valve atresia or single atrioventricular valve.Circulation. 1987; 76: III53-III60PubMed Google Scholar in 1987 to address the issue of atrial septation, the LT technique became a major modification to the Fontan operation following a series of detailed hydrodynamic studies by de Leval.19de Leval M.R. Kilner P. Gewillig M. Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. Experimental studies and early clinical experience.J Thorac Cardiovasc Surg. 1988; 96: 682-695Abstract Full Text PDF PubMed Google Scholar His work demonstrated that chamber pulsation (as with right atrial contraction), sharp corners, and regions of expansion increase the degree of turbulence, energy loss, and effective stenosis in the chamber and/or downstream vessel/conduit. De Leval and colleagues19de Leval M.R. Kilner P. Gewillig M. Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. Experimental studies and early clinical experience.J Thorac Cardiovasc Surg. 1988; 96: 682-695Abstract Full Text PDF PubMed Google Scholar confirmed the hydrodynamic benefits of the linearized inferior vena cava (IVC) flow to the pulmonary vasculature through a lateral tunnel. Humes and colleagues20Humes R.A. Feldt R.H. Porter C.J. Julsrud P.R. Puga F.J. Danielson G.K. The modified Fontan operation for asplenia and polysplenia syndromes.J Thorac Cardiovasc Surg. 1988; 96: 212-218Abstract Full Text PDF PubMed Google Scholar and Marcelletti and colleagues21Marcelletti C. Corno A. Giannico S. Marino B. Inferior vena cava-pulmonary artery extracardiac conduit. A new form of right heart bypass.J Thorac Cardiovasc Surg. 1990; 100: 228-232Abstract Full Text PDF PubMed Google Scholar and later reported the successful use of an extracardiac conduit. Its hypothesized benefits were the avoidance of intra-atrial prosthetic material, reduced risk of pulmonary venous obstruction, and potential reduced risk of supraventricular arrhythmias associated with atrial incisions, suture lines, and gradual distension of the atrial portion of the Fontan pathway. Minimizing Fontan pathway energy loss is paramount for avoiding both early and late complications. In addition, surgeons need to keep in mind that they have to construct the geometry of the anastomoses in a way that allows hepatic blood flow to both lungs, because the lack of this flow has been associated with the development of pulmonary arteriovenous malformations. The work by de Leval and later confirmed by Sharma and colleagues22Sharma S. Goudy S. Walker P. Panchal S. Ensley A. Kanter K. et al.In vitro flow experiments for determination of optimal geometry of total cavopulmonary connection for surgical repair of children with functional single ventricle.J Am Coll Cardiol. 1996; 27: 1264-1269Crossref PubMed Scopus (123) Google Scholar and Lardo and colleagues23Lardo A.C. Webber S.A. Friehs I. del Nido P.J. Cape E.G. Fluid dynamic comparison of intra-atrial and extracardiac total cavopulmonary connections.J Thorac Cardiovasc Surg. 1999; 117: 697-704Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar demonstrated that a degree of caval offset and flaring of the anastomosis can significantly reduce flow collision, recirculation, and subsequently energy loss.24de Leval M.R. Dubini G. Migliavacca F. Jalali H. Camporini G. Redington A. et al.Use of computational fluid dynamics in the design of surgical procedures: application to the study of competitive flows in cavo-pulmonary connections.J Thorac Cardiovasc Surg. 1996; 111: 502-513Abstract Full Text Full Text PDF PubMed Scopus (235) Google Scholar Tang and colleagues25Tang E. Restrepo M. Haggerty C.M. Mirabella L. Bethel J. Whitehead K.K. et al.Geometric characterization of patient-specific total cavopulmonary connections and its relationship to hemodynamics.JACC Cardiovasc Imaging. 2014; 7: 215-224Crossref PubMed Scopus (55) Google Scholar demonstrated significant variability within both LT and ECC based on the anastomotic positions and angulations.25Tang E. Restrepo M. Haggerty C.M. Mirabella L. Bethel J. Whitehead K.K. et al.Geometric characterization of patient-specific total cavopulmonary connections and its relationship to hemodynamics.JACC Cardiovasc Imaging. 2014; 7: 215-224Crossref PubMed Scopus (55) Google Scholar Lardo and colleagues,23Lardo A.C. Webber S.A. Friehs I. del Nido P.J. Cape E.G. Fluid dynamic comparison of intra-atrial and extracardiac total cavopulmonary connections.J Thorac Cardiovasc Surg. 1999; 117: 697-704Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar in their comparison of intra-atrial tunnel and extracardiac conduit, showed significantly lower energy loss in the ECC model. They also demonstrated that a mismatch in IVC–Fontan conduit size results in more energy loss, with a 1:1 size ratio as the most efficient. This further supports de Leval's original report that dilation of the pathway (through enlarged conduits or dilated intra-atrial tunnels) results in substantial energy loss.19de Leval M.R. Kilner P. Gewillig M. Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. Experimental studies and early clinical experience.J Thorac Cardiovasc Surg. 1988; 96: 682-695Abstract Full Text PDF PubMed Google Scholar Contrary to the above evidence, Bove and colleagues,26Bove E.L. de Leval M.R. Migliavacca F. Guadagni G. Dubini G. Computational fluid dynamics in the evaluation of hemodynamic performance of cavopulmonary connections after the Norwood procedure for hypoplastic left heart syndrome.J Thorac Cardiovasc Surg. 2003; 126: 1040-1047Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar in their assessment of the fluid dynamics in various Fontan configurations, reported that the lowest energy loss was noted in LT Fontan, particularly following hemi-Fontan construction. They theorized that this may be due to the ease of caval offset and flaring of the cavopulmonary anastomosis, avoiding caval flow clashing and turbulence. Although interesting, these fluid dynamic studies have not been able to profoundly influence our Fontan surgery and at this stage, do not seem to help us identify the superiority of one of these techniques. One potential disadvantage of the ECC is its lack of capacity for growth. Any long-term outcomes may be affected by the size of conduit used. Early studies noted that IVC diameter at 2 to 4 years is approximately 80% of adult size, with significant variability among patients.27Alexi-Meskishvili V. Ovroutski S. Ewert P. Dähnert I. Berger F. Lange P.E. et al.Optimal conduit size for extracardiac Fontan operation.Eur J Cardiothorac Surg. 2000; 18: 690-695Crossref PubMed Scopus (84) Google Scholar Several studies that examined ideal conduit size in relation to long-term outcomes and exercise capacity concluded that conduit oversizing may be more detrimental to outcomes owing to flow stagnation, energy loss, and the increased risk of thromboembolic events.28Itatani K. Miyaji K. Tomoyasu T. Nakahata Y. Ohara K. Takamoto S. et al.Optimal conduit size of the extracardiac Fontan operation based on energy loss and flow stagnation.Ann Thorac Surg. 2009; 88 (discussion 572-3): 565-572Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar,29Lee S.Y. Song M.K. Kim G.B. Bae E.J. Kim S.H. Jang S.I. et al.Relation between exercise capacity and extracardiac conduit size in patients with Fontan circulation.Pediatr Cardiol. 2019; 40: 1584-1590Crossref PubMed Scopus (10) Google Scholar In an exercise study analysis, Lee and colleagues30Cetta F. Burkhart H.M. The Fontan extracardiac conduit: one size does not fit all.Transl Pediatr. 2018; 7: 233-234Crossref PubMed Scopus (6) Google Scholar recently identified that the ideal conduit size is 12.5 mm/m2 (16 to 18 mm on average) and that larger conduit sizes are worse. Others have claimed that Fontan-associated liver disease may be higher with ECC, especially with smaller conduits.30Cetta F. Burkhart H.M. The Fontan extracardiac conduit: one size does not fit all.Transl Pediatr. 2018; 7: 233-234Crossref PubMed Scopus (6) Google Scholar There is a considerable variation in mortality following the 2 techniques. Most would consider the early outcomes of these techniques equivalent, but 2 articles reported significant differences. Weixler and colleagues1Weixler V.H.M. Zurakowski D. Kheir J. Guariento A. Kaza A.K. Baird C.W. et al.Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit.J Thorac Cardiovasc Surg. 2020; 159: 1480-1491.e2Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar described their experience with >800 patients from the Boston group between 2000 and 2017, with the majority undergoing a LT Fontan (n = 638). They reported a higher rate of early mortality following ECC Fontan compared with their LT cohort (3.1% vs 0.5%; P < .01), despite the fact that patients who underwent LT seemed to have more adverse risk factors. Patients who underwent LT had a higher incidence of right ventricular dominance and hypoplastic left heart syndrome (HLHS), and higher pulmonary artery pressure and pulmonary vascular resistance. A 2012 analysis of 2747 Fontan procedures performed in 68 centers between 2000 and 2009 recorded in the Society of Thoracic Surgeons (STS) database showed higher mortality in patients who underwent ECC Fontan (2.1% vs 0.9%; P = .02).8Stewart R.D. Pasquali S.K. Jacobs J.P. Benjamin D.K. Jaggers J. Cheng J. et al.Contemporary Fontan operation: association between early outcome and type of cavopulmonary connection.Ann Thorac Surg. 2012; 93 (discussion 1261): 1254-1260Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar This is in contrast to a recent large single-center study from Philadelphia of 773 patients from 1992 to 2009 that reported a higher overall operative mortality of 3.5%, with no difference between ECC and LT.3Downing T.E. Allen K.Y. Glatz A.C. Rogers L.S. Ravishankar C. Rychik J. et al.Long-term survival after the Fontan operation: twenty years of experience at a single center.J Thorac Cardiovasc Surg. 2017; 154: 243-253.e2Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar In addition, the Australia and New Zealand Fontan Registry reported a low early mortality rate of 1.3% for ECC across a similar era (1997-2010) and up to 2.0% operative mortality for the LT technique (P = .8).6Iyengar A.J. Winlaw D.S. Galati J.C. Celermajer D.S. Wheaton G.R. Gentles T.L. et al.Trends in Fontan surgery and risk factors for early adverse outcomes after Fontan surgery: the Australia and New Zealand Fontan registry experience.J Thorac Cardiovasc Surg. 2014; 148: 566-575Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar,31Wilson T.G. Shi W.Y. Iyengar A.J. Winlaw D.S. Cordina R.L. Wheaton G.R. et al.Twenty-five year outcomes of the lateral tunnel Fontan procedure.Semin Thorac Cardiovasc Surg. 2017; 29: 347-353Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar Early morbidity following Fontan operations can present as prolonged pleural effusions, hospital stay, and early Fontan takedown. The Boston group recently noted that despite longer cross-clamp times (P = .01) and bypass times (P < .001) in the LT cohort, there was no difference in early postoperative morbidity between the 2 techniques, other than prolonged pleural effusions (3.9% for LT vs 8.6% for ECC; P < .01).1Weixler V.H.M. Zurakowski D. Kheir J. Guariento A. Kaza A.K. Baird C.W. et al.Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit.J Thorac Cardiovasc Surg. 2020; 159: 1480-1491.e2Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar Similarly, the Australia and New Zealand cohort reported no difference between LT and ECC in early failure (6% vs 4%; P = .2), prolonged effusions (6% vs 8%; P = .2), or a composite of early adverse outcomes, including length of stay (17% vs 13%; P = .7).6Iyengar A.J. Winlaw D.S. Galati J.C. Celermajer D.S. Wheaton G.R. Gentles T.L. et al.Trends in Fontan surgery and risk factors for early adverse outcomes after Fontan surgery: the Australia and New Zealand Fontan registry experience.J Thorac Cardiovasc Surg. 2014; 148: 566-575Abstract Full Text Full Text PDF PubMed Scopus (75) Google Scholar However, the STS database review, which accounted for patient characteristics, procedural factors, and center volume, found worse early outcomes on multivariable analysis in the ECC group with more takedown/revisions (0.7% for LT vs 1.7% for ECC; P = .03), increased length of stay (9 days vs 10 days; P < .001), and postoperative complications (32% vs 45%).8Stewart R.D. Pasquali S.K. Jacobs J.P. Benjamin D.K. Jaggers J. Cheng J. et al.Contemporary Fontan operation: association between early outcome and type of cavopulmonary connection.Ann Thorac Surg. 2012; 93 (discussion 1261): 1254-1260A
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