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A sword threatening the heart: The scimitar syndrome

2020; Elsevier BV; Volume: 1; Linguagem: Inglês

10.1016/j.xjtc.2020.01.017

2666-2507

Vladimiro L. Vida, Alvise Guariento,

Congenital Heart Disease Studies

Central MessageThis review deals with the natural and surgical history of patients with scimitar syndrome, describing the clinical presentation and possible results based on the choice of treatment.See Commentary on page 81. This review deals with the natural and surgical history of patients with scimitar syndrome, describing the clinical presentation and possible results based on the choice of treatment. See Commentary on page 81. Scimitar syndrome (SS) is a rare congenital heart anomaly consisting of anomalous venous drainage of part or the entire right lung into the upper portion of the inferior vena cava (IVC), right lung hypoplasia, and a variable systemic arterial blood supply to the right lung.1Vida V.L. The Complete Reference for Scimitar Syndrome. Academic Press, London2017Google Scholar,2Opotowsky A.R. Webb G.D. A battle in the crusade to understand scimitar syndrome.Eur Heart J. 2018; 39: 1012-1014Crossref PubMed Scopus (5) Google Scholar This malformation has been described by many pathologists over time. In an article published in 1956 by Halasz and colleagues,3Halasz N.A. Halloran K.H. Liebow A.A. Bronchial and arterial anomalies with drainage of the right lung into the inferior vena cava.Circulation. 1956; 14: 826-846Crossref PubMed Scopus (95) Google Scholar the word scimitar was used for the first time to describe the shape of this anomalous pulmonary venous connection. However, it was only in 1960 that Catherine Neill and colleagues4Neill C.A. Ferencz C. Sabiston D. Sheldon H. The familial occurrence of hypoplastic right lung with systemic arterial supply and venous drainage "scimitar syndrome.".Bull Johns Hopkins Hosp. 1960; 107: 1-21PubMed Google Scholar named the syndrome, characterizing it and linking it to the radiologic appearance of a sword adjacent to the edge of the right heart that can sometimes be found at diagnosis. The incidence of SS is relatively low, representing 3% to 6% of the partial anomalous venous connections.1Vida V.L. The Complete Reference for Scimitar Syndrome. Academic Press, London2017Google Scholar Previous studies were based on single-center experiences or rather small, multicenter studies.5Wang C.C. Wu E.T. Chen S.J. Lu F. Huang S.C. Wang J.K. et al.Scimitar syndrome: incidence, treatment, and prognosis.Eur J Pediatr. 2008; 167: 155-160Crossref PubMed Scopus (58) Google Scholar, 6Vida V.L. Speggiorin S. Padalino M.A. Crupi G. Marcelletti C. Zannini L. et al.The scimitar syndrome: an Italian multicenter study.Ann Thorac Surg. 2009; 88: 440-444Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar, 7Vida V.L. Padalino M.A. Boccuzzo G. Tarja E. Berggren H. Carrel T. et al.Scimitar syndrome: a European Congenital Heart Surgeons Association (ECHSA) multicentric study.Circulation. 2010; 122: 1159-1166Crossref PubMed Scopus (94) Google Scholar, 8Dupuis C. Charaf L.A.C. Brevière G.M. Abou P. Rémy-Jardin M. Helmius G. The "adult" form of the scimitar syndrome.Am J Cardiol. 1992; 70: 502-507Abstract Full Text PDF PubMed Scopus (167) Google Scholar, 9Dupuis C. Charaf L.A.C. Breviere G.M. Abou P. "Infantile" form of the scimitar syndrome with pulmonary hypertension.Am J Cardiol. 1993; 71: 1326-1330Abstract Full Text PDF PubMed Scopus (109) Google Scholar, 10Dusenbery S.M. Geva T. Seale A. Valente A.M. Zhou J. Sena L. et al.Outcome predictors and implications for management of scimitar syndrome.Am Heart J. 2013; 165: 770-777Crossref PubMed Scopus (33) Google Scholar, 11Vida V.L. Padrini M. Boccuzzo G. Agnoletti G. Bondanza S. Butera G. et al.Natural history and clinical outcome of "uncorrected" scimitar syndrome patients: a multicenter study of the Italian Society of Pediatric Cardiology.Rev Española Cardiol (Engl Ed). 2013; 66: 556-560Crossref PubMed Scopus (21) Google Scholar, 12Brink J. Yong M.S. d'Udekem Y. Weintraub R.G. Brizard C.P. Konstantinov I.E. Surgery for scimitar syndrome: the Melbourne experience.Interact Cardiovasc Thorac Surg. 2015; 20: 31-34Crossref PubMed Scopus (17) Google Scholar, 13Wang H. Kalfa D. Rosenbaum M.S. Ginns J.N. Lewis M.J. Glickstein J.S. et al.Scimitar syndrome in children and adults: natural history, outcomes, and risk analysis.Ann Thorac Surg. 2018; 105: 592-598Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar However, our group was recently able to conduct a multicenter study on behalf of the European Pediatric Cardiology Association and the European Congenital Heart Surgeons Association.14Vida V.L. Guariento A. Milanesi O. Gregori D. Stellin G. Scimitar Syndrome Study GroupThe natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study.Eur Heart J. 2018; 39: 1002-1011Crossref PubMed Scopus (21) Google Scholar This led to the collection of nearly 500 patients with SS from 51 centers, the largest series of patients with SS evaluated so far. In this review, we arbitrarily divided patients into 3 groups according to their age at diagnosis: neonates/infants ( 25 mm Hg at rest or 50% above systemic level) is often present before surgery (38% of patients) and must always be addressed before surgery, either by medical treatment or by reducing the Qp/Qs ratio by coil embolization. Therefore, isolated forms of SS are generally treated in the case of a Qp/Qs ratio >1.5:1 or Qp/Qs ratio <1.5:1 with a clinically treated pulmonary hypertension. However, the right choice for this particular group of patients remains controversial.Table 2Demographics and surgical data of a series of patients with scimitar syndrome undergoing surgery (n = 279)Mean ± SEM or nDemographics Male patients109/279 (39%) Age at surgery, mo10.2 ± 0.9 Group of age at diagnosis 1 y; 10 y59/279 (21%)Characteristics Symptoms at diagnosis210/279 (76%)Cardiac symptoms at diagnosis147/279 (53%)Respiratory symptoms at diagnosis142/279 (51%) Need for medications at diagnosis48/279 (17%) Pulmonary hypertension at diagnosis105/279 (38%) mPAP at diagnosis, mm Hg29.2 ± 0.1 Associated CHDs194/279 (69%)Atrial septal defect168/279 (60%)Complex CHDs63/279 (23%) SAS to the right lung130/279 (47%) Coil embolization of SAS93/279 (33%) Degree of right pulmonary hypoplasiaMild110/279 (39%)Moderate61/279 (22%)Severe18/279 (6%)Operative data Type of procedureCorrective surgery254/279 (91%)Resective25/279 (9%) Type of corrective surgeryIntracardiac baffle176/254 (69%)Direct scimitar vein reimplantation78/254 (31%) Type of resective surgeryLobectomy18/25 (72%)Pneumectomy7/25 (28%) Associated surgical procedure101/279 (36%) CBP time, min127.2 ± 5.4 Aortic crossclamp time, min62.5 ± 3.2 Circulatory arrest time, min28.3 ± 6.4SEM, Standard error of the mean; mPAP, mean pulmonary artery pressure; CHD, congenital heart disease; SAS, systemic arterial supply; CBP, cardiopulmonary bypass. Open table in a new tab SEM, Standard error of the mean; mPAP, mean pulmonary artery pressure; CHD, congenital heart disease; SAS, systemic arterial supply; CBP, cardiopulmonary bypass. Surgical treatment includes correction of abnormal venous drainage in most patients (>90%), but right lung resection may be required in more severe forms. In any case, nonetheless, the abnormal systemic supply to the right lung should be ligated and all associated CHDs should be repaired. Surgical options for the redirection of the anomalous SV in the left atrium can consist of intracardiac baffle (69% of cases) or direct SV reimplantation (31% of cases).14Vida V.L. Guariento A. Milanesi O. Gregori D. Stellin G. Scimitar Syndrome Study GroupThe natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study.Eur Heart J. 2018; 39: 1002-1011Crossref PubMed Scopus (21) Google Scholar There are several surgical corrective options for the pulmonary venous return re-routing,16Çiçek S. Arslan A.H. Ugurlucan M. Yildiz Y. Ay S. Scimitar syndrome: the curved Turkish sabre.Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2014; 17: 56-61Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar which can be accomplished both via a right thoracotomy or sternotomy (Figure 1, Video 1). One of the first options described involved the creation of a pericardial tunnel baffling flow from the orifice of the SV at the level of the IVC through the right atrium and then the connection of the baffle to the sides of the atrial septal defect17Zubiate P. Kay J.H. Surgical correction of anomalous pulmonary venous connection.Ann Surg. 1962; 156: 234-250Crossref PubMed Google Scholar (Figure 1, A). Another technique includes the resection of the SV orifice with a cuff of the IVC and subsequent reimplantation in the left atrium and IVC patch enlargement18Varghese R. Omoregbee B. Saheed S. Scimitar syndrome: surgical approach to an unusual anatomy of the scimitar vein.Ann Pediatr Cardiol. 2016; 9: 173-175Crossref PubMed Scopus (1) Google Scholar (Figure 1, B). Brown and colleagues19Brown J.W. Ruzmetov M. Minnich D.J. Vijay P. Edwards C.A. Uhlig P.N. et al.Surgical management of scimitar syndrome: an alternative approach.J Thorac Cardiovasc Surg. 2003; 125: 238-245Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar described a direct anastomosis of the SV, with full dissection of the SV, incision of the diaphragm, and reimplantation through a window excised posterior to the phrenic nerve. Recently, new techniques have been proposed, such that by Lugones and García,20Lugones I. García R. A new surgical approach to scimitar syndrome.Ann Thorac Surg. 2014; 97: 353-355Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar in which the pulmonary venous return is widely connected to the left atrium through a tunnel constructed with the in situ pericardium.Figure 1A, Intracardiac baffle technique. B, Reimplantation technique. The asterisk shows the intracardiac baffle. SV, Scimitar vein; ASD, atrial septal defect; IVC, inferior vena cava; LA, left atrium.View Large Image Figure ViewerDownload (PPT) Nowadays, the role of a right pulmonary lobectomy or more rarely a right pulmonary pneumectomy has been limited to the presence of severe right pulmonary hypoplasia, recurrent upper respiratory tract infections unresponsive to medical treatment, diffuse bronchiectasia, persistent hemoptysis, or intra-atrial baffles thrombosis after corrective surgery. Postoperative complications occur in 33% of the patients and usually include respiratory failure (39%) and congestive heart failure (26%). The hospital mortality rate is generally low (6%) and lower for patients undergoing corrective surgery (3%), rather than resective procedures (36%). Late mortality is around 4% at a mean follow-up of 7 years, with an overall mortality of 10% of the patients. Overall survival probability at 30 years of age is 88% and is lower in patients with associated CHDs and pulmonary hypertension. In the STPs, most of the deaths are caused by congestive heart failure (57%), but also by pulmonary hypertension (22%) and respiratory failure (14%). Most STPs are asymptomatic at the last clinical examination (71%) (Figure 2) and only 20% of patients still need medications (Table 3). In contrast, there is a slight increase in symptomatic patients in clinically monitored patients due to both for cardiac and respiratory symptoms. None of the asymptomatic patients at diagnosis develops symptoms after surgical treatment.14Vida V.L. Guariento A. Milanesi O. Gregori D. Stellin G. Scimitar Syndrome Study GroupThe natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study.Eur Heart J. 2018; 39: 1002-1011Crossref PubMed Scopus (21) Google ScholarTable 3Outcomes of a series of scimitar syndrome patients undergoing surgery (n = 279)Mean ± SEM or nEarly outcomes Postoperative complications93/279 (33%)Respiratory failure36/93 (39%)Congestive heart failure21/93 (26%)Sepsis16/93 (17%)Pericardial/pleural effusion14/93 (15%)Arrhythmia14/93 (15%)Pulmonary hypertensive crisis14/93 (15%)Bleeding8/93 (9%)Delayed chest closure6/93 (6%) Hospital mortality17/279 (6%)Hospital mortality in case of corrective surgery8/254 (3%)Hospital mortality in case of resective surgery9/25 (36%)Late outcomes Late mortality11/279 (4%) Overall mortality28/279 (10%)Congestive heart failure16/28 (57%)Pulmonary hypertension6/28 (22%)Respiratory failure4/28 (14%)Bleeding2/28 (7%) Symptoms at follow-up80/279 (29%)Cardiac symptoms at follow-up49/279 (18%)Respiratory symptoms at follow-up31/279 (11%) Need for medications at follow-up52/279 (19%) Scimitar vein anastomosis presentingStenosis57/254 (22%)Occlusion6/254 (2%) Reoperation/recatheterization in case of corrective surgery42/254 (17%)Freedom from above, y6.3 ± 0.4SEM, Standard error of the mean. Open table in a new tab SEM, Standard error of the mean. Nevertheless, almost one quarter of the STPs present SV drainage disfunction after a corrective procedure. This included stenosis in 22% of cases or rarely total occlusion in 2% of patients. This diagnosis is not related to the type of corrective technique14Vida V.L. Guariento A. Milanesi O. Gregori D. Stellin G. Scimitar Syndrome Study GroupThe natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study.Eur Heart J. 2018; 39: 1002-1011Crossref PubMed Scopus (21) Google Scholar used and is more frequent in neonates/infants (33%) than in either children (20%) or adolescents/adults (14%). In addition, we found that there is an inverse linear correlation between age at correction and stenosis/occlusion of the scimitar drainage (the younger the patient, the higher the incidence of stenosis/occlusion).14Vida V.L. Guariento A. Milanesi O. Gregori D. Stellin G. Scimitar Syndrome Study GroupThe natural history and surgical outcome of patients with scimitar syndrome: a multi-centre European study.Eur Heart J. 2018; 39: 1002-1011Crossref PubMed Scopus (21) Google Scholar For this reason, an intracardiac baffle is usually recommended in younger patients whereas direct reimplantation is recommended in older ones. Of these patients with SV occlusion, 17% need an interventional cardiac catheterization or reoperation to address the failure, with average freedom of more than 6 years from the time of the first surgery (Figure 3, Table 3). In some patients with obstruction of the SV baffle, a pneumonectomy is required, and hemoptysis is often the first indication of this complication. The clinical presentation of patients with SS varies, mainly depending on age at diagnosis and associated CHDs. Pulmonary hypertension and the presence of associated CHDs are negative prognostic factors in patient survival, regardless of patient history.