Trisomy 18 (T18) is the second most common autosomal trisomy disorder surviving to birth, after Trisomy 21 [1, 2]. There are multiple congenital anomalies associated with T18 such as craniofacial defects, respiratory tract abnormalities, neurocognitive disability, and frequent cardiac lesions. Atrial septal defects (ASDs), ventricular septal defects (VSDs), and patent ductus arteriosus (PDA) make up the majority of congenital heart defects (CHD) in T18 patients. More complex congenital heart disease (CHD), such as Tetralogy of Fallot (TOF), double outlet right ventricle (DORV), complete atrioventricular canal defect, and coarctation of the aorta are not uncommon. Although uncommon, the single ventricle lesions are also diagnosed in this patient population [2-4]. The management of patients with T18 has evolved from the traditional non-interventional, palliative approach to a goal-directed, individualized approach. While this remains somewhat controversial, life-sustaining interventions such as intubation, mechanical ventilation, artificial hydration and nutrition, and cardiac and noncardiac surgeries are increasingly being considered and performed in patients with T18. VSD repair is the most common cardiac procedure performed in this patient population. The spectrum of cardiac procedures offered to T18 patients covers all aspects of congenital heart disease and all levels of complexity, from the Stage I Norwood procedure to an ASD repair [5].


In a large descriptive outcome study using data from the Society of Thoracic Surgeons Congenital Heart Surgery Database, the authors found that VSD repair constituted one third of all cardiac surgeries performed in patients with T18, followed by pulmonary artery banding in 18.5% of cases and right ventricle/right ventricular outflow tract reconstruction in 9.6% of cases. In this study, 28.5% of all cardiac operative procedures were classified into the Society of Thoracic Surgeons/European Association for Cardiothoracic Surgery Congenital Heart Surgery Mortality (STAT) category 4 and 5, indicating the highest complexity levels. Postoperative morbidity and mortality were much higher in T18 patients regardless of surgical complexity. The authors also found that preoperative mechanical ventilation was strongly associated with postoperative mortality. The authors then suggested that surgical candidacy of patients with T18 should be carefully considered in those who require preoperative mechanical ventilation [5]. Increased postoperative airway complications and requiring prolonged respiratory support were also described in this patient population[6].


References


1. Meyer R, Liu G, Gilboa S, et al. Survival of children with trisomy 13 and trisomy 18: A multi-state population-based study. Am J Med Genet A. 2016; 170A(4): 825-837.


2. Cereda A, Carey J. The trisomy 18 syndrome. Orphanet J Rare Dis. 2012; 7: 81.


3. Musewe N, Alexander D, Teshima I, Smallhorn J, Freedom R. Echocardiographic evaluation of the spectrum of cardiac anomalies associated with trisomy 13 and trisomy 18. J Am Coll Cardiol. 1990; 15(3): 673-677.


4. Rosa R, Rosa R, Lorenzen M, et al. Trisomy 18: frequency, types, and prognosis of congenital heart defects in a Brazilian cohort. Am J Med Genet A. 2012; 158A(9): 2358-2361.


5. Cooper D, Riggs K, Zafar F, et al. Cardiac Surgery in Patients With Trisomy 13 and 18: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database. J Am Heart Assoc. 2019; 8(13): e012349. DOI: 10.1161/JAHA.119.012349.


6. Swanson S, Schumacher K, Ohye R, Zampi J. Impact of trisomy 13 and 18 on airway anomalies and pulmonary complications after cardiac surgery. J Thorac Cardiovasc Surg. 2020; 162(1): 241-249.