Ann Thorac Surg 2007;83:680-682
© 2007 The Society of Thoracic Surgeons
Case Reports
Ruptured Tricuspid Valve Papillary Muscle: A Treatable Cause of Neonatal Cyanosis
Ritu Sachdeva, MDa,*,
Richard T. Fiser, MDa,
William R. Morrow, MDa,
Joseph R. Cava, MD, PhDb,
Nancy S. Ghanayem, MDc,
Robert D.B. Jaquiss, MDd
a Pediatric Cardiology, Arkansas Children’s Hospital and University of Arkansas for Medical Sciences, Little Rock, Arkansas
d Pediatric Cardiothoracic Surgery, Arkansas Children’s Hospital and University of Arkansas for Medical Sciences, Little Rock, Arkansas
b Pediatric Cardiology, Children’s Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, Wisconsin
c Pediatric Critical Care Medicine, Children’s Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, Wisconsin
Accepted for publication June 23, 2006.
* Address correspondence to Dr Sachdeva, 800 Marshall St, Slot 512-3, Little Rock, AR 72202. (Email: sachdevaritu{at}uams.edu).
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Abstract
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Severe tricuspid regurgitation resulting from a flail leaflet is a rare cause of neonatal cyanosis. We report two neonates with profound cyanosis and severe tricuspid regurgitation caused by rupture of the papillary muscle supporting the anterior leaflet, without other structural heart defects. Ductal patency could not be established. Repair of the tricuspid valve was performed by reimplantation of the ruptured papillary muscle head, after initial stabilization using extracorporeal membrane oxygenation. Early recognition and treatment of this otherwise fatal condition can be lifesaving.
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Introduction
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Isolated "functional" tricuspid insufficiency (TR) is a transient, benign finding in stressed neonates [1]. In rare cases, the insufficiency may be caused by papillary muscle rupture [2]. Unrecognized, this diagnosis may prove fatal [3, 4]. We report two neonates with severe TR resulting from prenatal papillary muscle rupture in the setting of premature ductal closure. Both underwent repair by papillary muscle reimplantation, after stabilization with extracorporeal membrane oxygenation (ECMO).
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Case Reports
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Patient 1
A 3100-gram male infant born at 38 week’s gestation was profoundly cyanotic and apneic, requiring immediate endotracheal intubation and the administration of prostaglandin. He remained cyanotic, with oxygen saturations of less than 60%. After transfer to Children’s Hospital of Wisconsin at 4 hours of age, an echocardiogram showed normal segmental anatomy. The right ventricle was dilated and hypertrophied, and severe TR resulted from a prolapsing, echo bright anterior leaflet. Diffuse echo bright areas were present in the right ventricle. Antegrade pulmonary flow was reduced with a large right-to-left shunt at the foramen ovale, and no patent ductus arteriosus (PDA) was present.
The infant was treated with nitric oxide, milrinone, and continued mechanical ventilation without improvement, and he was placed on venoarterial ECMO. Despite nitric oxide, milrinone, and sildenafil, efforts to wean from ECMO were unsuccessful over 12 days, and tricuspid repair was undertaken.
At surgery, a flail anterior leaflet was found, with no subvalvular support at all. There was a segment of scarred muscle on the central portion of subvalvar chordae on the anterior leaflet and a corresponding scarred papillary muscle head in that region. Cardiopulmonary bypass was instituted at normothermia using ascending aorta, superior and inferior vena cava cannulation. Tricuspid repair consisted of reimplantation of the scarred papillary muscle head into the healthy endocardium, adjacent to the infracted base of the papillary muscle. In addition, a modified Kay annuloplasty was performed to imbricate the annulus at the posterior leaflet [5]. Commissuroplasty was also performed at the septal/anterior commissure.
The patient weaned easily from bypass on low-dose epinephrine, milrinone, and dopamine. Nitric oxide was used empirically but was weaned along with inotropic infusions over next few days. Postoperative transesophageal echocardiography in the operating room showed mild tricuspid insufficiency. The patient was well at last follow-up at 15 months of age, and the echocardiogram continued to show only mild tricuspid insufficiency.
Patient 2
A 2925-gram male infant was delivered at 39 week’s gestation by cesarean section because of meconium staining and fetal decelerations. He was transferred to Arkansas Children’s Hospital because of profound cyanosis and respiratory distress. Despite prostaglandin infusion, ventilation with 100% oxygen, and nitric oxide, saturations remained at less than 60%.
Echocardiography showed normal segmental anatomy with right ventricular hypertrophy, a flail segment of the anterior tricuspid leaflet, and severe TR. The regurgitant jet was directed towards the atrial septum, resulting in a large right-to-left atrial shunt. The tricuspid papillary muscle and flail segment of the tricuspid leaflet appeared echo bright, suggesting in utero ischemic insult (Fig 1). There was minimal forward pulmonary flow and no PDA. An area of calcification was present in the usual ductal location (Fig 2).
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Fig 1. Four-chamber echocardiogram shows echo bright papillary muscle head (arrow) with echo bright and flail anterior tricuspid leaflet (*) resulting in incomplete central coaptation. (LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.)
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Fig 2. Parasternal short-axis echocardiogram shows echo bright density (arrow) in the ductal region suggestive of calcification. (Ao = aorta; LPA = left pulmonary artery; RPA = right pulmonary artery.)
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The neonate was placed on venoarterial ECMO within 2 hours of arrival, and tricuspid valve repair was performed 18 hours later. At surgery, there was healed necrosis of a small papillary muscle supporting the posteroseptal region of the valve and a ruptured papillary muscle supporting most of the anterior leaflet. The anterior leaflet prolapsed completely, and only a small portion of the papillary muscle remained attached to this valve segment.
Cardiopulmonary bypass was instituted at mild hypothermia using aortic and bicaval cannulation. Two horizontal mattress 6-0 polypropylene sutures, reinforced with pericardial pledgets, were then used to reimplant the ruptured head of papillary muscles into the base of the muscle. When the valve was tested again, it appeared much more competent. It was not deemed necessary to perform an annuloplasty because the tricuspid annulus was not dilated.
The patient weaned easily from bypass on low levels of inotropic support (milrinone, dopamine, and epinephrine) and empiric nitric oxide. Nitric oxide and inotropic infusions were weaned over the next few days. Only mild TR was noted on the echocardiogram performed at the time of discharge from the hospital, 23 days after surgery.
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Comment
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Transient neonatal TR in the setting of a structurally normal valve is a well-described phenomenon that is thought to be related to perinatal hypoxia [1]. In contrast, TR caused by necrosis and rupture of the tricuspid valve papillary muscle is an ominous and potentially fatal condition [2–4]. TR secondary to papillary muscle rupture may be severe enough to preclude antegrade pulmonary flow, with a resultant massive right-to-left atrial shunt. Inability to open the ductus leaves little therapeutic option except ECMO.
The association of permanent antenatal ductal closure is of interest beyond its importance in limiting treatment options. If closure occurred suddenly, a tremendous increase in right ventricular afterload would result during severe fetal stress, and the combined hemodynamic and metabolic insult might provoke ischemic rupture of the tricuspid papillary muscle [6]. In one of our patients, an echo density was noted in the ductal region and was thought to represent chronic ductal occlusion. However, there was no history of late gestational intake of prostaglandin synthetase inhibitors (PSI) in our patients to explain premature ductal closure.
Alkalay and colleagues [3] reported a case of fatal neonatal TR secondary to papillary muscle rupture. Benvenuti and colleagues reported a fatal case of a 4-day-old infant with late gestational exposure to PSI [4]. Autopsy revealed infarction and rupture of the papillary muscle. Ingestion of PSI during pregnancy has been shown to have detrimental effects on fetal pulmonary vasculature by stimulating arteriolar smooth muscle differentiation and ductal constriction [7], resulting in persistent pulmonary hypertension in the newborn. Lim and colleagues [8] reported the neonatal repair of TR caused by papillary muscle rupture that used papillary muscle excision, creation of artificial Gore Tex (W.L. Gore and Associates, Flagstaff, Ariz) chordae, and tricuspid annuloplasty. Arrington and colleagues [9] reported a similar infant, who required ECMO as bridge to tricuspid valve repair.
A high mortality has been associated with neonatal TR resulting from flail tricuspid valve leaflets [3, 4]. Our cases demonstrate that timely recognition, ECMO support, and tricuspid valve repair may improve outcomes.
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References
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- Bucciarelli RL, Nelson RM, Egan EA, Eitzman DV, Gessner IH. Transient tricuspid insufficiency of the newborn: a form of myocardial dysfunction in stressed newborns Pediatrics 1977;59:330-337.[Abstract/Free Full Text]
- Donnelly WH, Bucciarelli RL, Nelson RM. Ischemic papillary muscle necrosis in stressed newborn infants J Pediatr 1980;96:295-300.[Medline]
- Alkalay AL, Ferry DA, Pepkowitz SH, Chou PJ, Oakes GK, Pomerance JJ. Critical tricuspid insufficiency due to papillary muscle ruptureA result of prenatal hypoxic insult. Am J Dis Child 1988;142:753-755.[Abstract/Free Full Text]
- Benvenuti LA, Aiello VD, Cury AJ, Ebaid M. Post-ischemic rupture of the anterior papillary muscle of the right ventricle associated with persistent pulmonary hypertension of the newborn: a case report Am J Cardiovasc Pathol 1992;4:79-84.[Medline]
- Kay JH. Surgical treatment of tricuspid regurgitation Ann Thorac Surg 1992;53:1132-1133.[Abstract]
- Setzer E, Ermocilla R, Tonkin I, John E, Sansa M, Cassady G. Papillary muscle necrosis in a neonatal autopsy population: incidence and associated clinical manifestations J Pediatr 1980;96:289-294.[Medline]
- Levin DL, Fixler DE, Morriss FC, Tyson J. Morphologic analysis of the pulmonary vascular bed in infants exposed in utero to prostaglandin synthetase inhibitors J Pediatr 1978;92:478-483.[Medline]
- Lim KA, Huh J, Jun TG. Successful repair of critical tricuspid regurgitation secondary to ruptured papillary muscle in a newborn Cardiol Young 2004;14:450-452.[Medline]
- Arrington CB, Kouretas PC, Mart CR. Extracorporeal membrane oxygenation as a bridge to surgical treatment of flail tricuspid valve in a neonate Cardiol Young 2005;15:660-662.[Medline]
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Abstract
Introduction
