Perioperative Management of Neonatal Ectopia Cordis: Report of Three Cases James H. Diaz, MD,

MHA

Departments of Anesthesiology and Pediatrics, Ochsner Clinic and Alton Ochsner Medical Foundation; and Department of Anesthesiology, Tulane University School of Medicine, New Orleans, Louisiana

ctopia cordis or heterotopic heart (1) is a rare congenital cardiac anomaly (7

Table 1. Immediate Preanesthetic Status and Therapeutic Interventions in Three Infants With Ectopia Cordis Status

Case 1

Case 2

Case 3

Ectopia type Temperature ("C) Heart rate (bpm) Arterial blood pressure (mm Hg)

Thoracic 36.5 168 60130 NA 55 23 7.36 -13.8 3.0 24 20/0 None

Thoracoabdominal 37.0 142 58/30 92 47 42 7.35 -23 3.5

Abdominal 36.8 156 75/40 NA 32 51 7.22 -20 3.0 120 3014 None a

STC02

(%)

Pao, (mm Hg) Paco, (mm Hg) PHa Base excess Endotracheal tube OD (mm) Ventilator rate (breathsfmin) Ventilator pressures (cm H,O) Vasopressors Intravenous fluids

60

2514 None a

a

~~

STCO,, transcutaneous 0, saturation; Pao,, arterial 0, tension; Paco,, arterial CO, tension; OD, outside diameter; NA, not available. "Fluids for all = D,,W with 3 mEq NaCl + 2 mEq KC1 per 100 mL infused at 8 mL.kg-'.h-'.

Table 2. Classification of Ectopia Cordis" ~~

Type Cervical (heart covered with skin and precervical fascia)

No. of cases reported to date

Frequency

(%I

18

8.2

Thoracic (heart exposed or partially covered with skin and prestemal fascia)

81

36.8

Thoracoabdominal (pentalogy of Cantrell)

80

36.3

Abdominal

25

11.4

Unclassified

16

7.3

Total

220

100

Sites of associated anomalies Sternal cleft Craniofacial Intracardiac Chest wall (cleft or bifid sternum) Intracardiac Abdominal wall Chest wall @ifid or absent sternum) Intracardiac Diaphragm Abdominal wall Intracardiac Diaphragm Abdominal wall NA 70+% have major associated anomalies

NA, not applicable. "Adapted with permission from Leca et al. (1)

section under general endotracheal anesthesia. A large ventral wall defect containing the heart, the liver, and small bowel loops was recognized. Echocardiographic evaluation demonstrated an intact sternum; a large omphalocele containing the heart, liver, spleen, and small bowel loops; a double-outlet right ventricle; a large ventricular septa1 defect; valvular pulmonic stenosis; a patent foramen ovale; total anomalous pulmonary venous return; and an absent pericardium. In addition, the heart was noted to be prolapsed through a large midline defect in the diaphragm. Chromosomal karyotype was 46 XX. High-frequency ventilation with 100% inspired oxygen therapy was instituted for progressive respiratory failure with chronic hypoxemia. On the fifth day of life, the infant developed asystolic cardiac arrest and was not resuscitated.

Discussion With the increasing use of real-time sonography in obstetrics, the diagnosis of ectopia cordis will be made more frequently in the prenatal period (case 3) (2-5). The prenatal diagnosis of ectopia cordis should stimulate a vigorous sonographic search for other associated anomalies, particularly omphaloceles and craniofacial defects such as microcephaly and hydrocephalus (3-5). The etiology of ectopia cordis is unknown. A weak association with trisomy 18 (one case) has been suggested, and chromosomal karyotyping is now recommended in all cases to improve genetic coun-

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CASE REPORTS

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Table 3. Specific Anomalies Associated With Ectopia Cordis in Order of Frequency of Occurrence‘ Sites of anomalies ~

Craniofacial

Chest wall

Microcephaly Hydrocephalus Cleft palate Cleft lip Anencephaly Neural tube defect

Cleft sternum Bifid sternum Absent sternum

Intracardiac Septa1 defects Outflow tract obstructions Cardiac diverticuli Double-outlet right ventricle Anomalies of caval and pulmonary venous return Transposition of the great arteries Aortic coarctation Truncus arteriosus

Abdominal wall Omphalocele Diastasis recti Gastroschisis

“Data from Leca et al. (1) and Harrison et al. (2).

Figure 1. Twelve-hour-old neonate with complete thoracic ectopia cordis and bifid sternum with the entire heart exposed (case 2). Note prominent right and left auricular appendages or diverticuli and associated omphalocele with attached umbilical cord. The right arm is extended for radial artery cannulation (top of photograph).

seling (3,5). Omphalocele and ectopia cordis may both result from the failure of timely fusion of the cephalic anterior body folds and are commonly associated anomalies (6). Some anterior fusion defects and some forms of ectopia cordis may also be caused by the amniotic band syndrome (6). Early plans may now be made for cesarean delivery of the fetus with ectopia cordis amenable to surgical palliation or repair (2).Vaginal delivery could cause prolonged cardiac compression, damage herniated viscera, or rupture atrial diverticuli or omphalocele sacs (2). After atraumatic abdominal delivery, the neonate with ectopia cordis, omphalocele, and correctable intracardiac anomalies may be considered for staged postnatal repairs (1,2,7). If, however, prenatal echocardiography shows uncorrectable intracardiac lesions, consideration should be given to elective termination of pregnancy in the first or early second trimester (1,3-5,7).

Immediate treatment of an infant with ectopia cordis should begin at birth and consists of covering the lesion with saline-soaked gauze pads and gently wrapping the thorax and trunk circumferentially to prevent heat loss and desiccation of the ectopic heart and omphalocele, if present (2,4). No pressure should be applied over the extrathoracic heart as any compression might reduce venous return to the heart, reduce cardiac filling, and decrease cardiac output. Compression of the omphalocele sac should also be avoided as it may force herniated viscera into a limited abdominal cavity, elevating the hemidiaphragms and restricting alveolar ventilation (8). After emergency management, more complete preoperative evaluation can be undertaken, such as computerized axial tomography to evaluate thoracic volumes and capacities (6) and echocardiography to confirm the presence or absence of commonly associated intracardiac defects (6) (Table 2). In hemodynamically stable neonates, the extrathoracic heart should then be quickly covered with skin flaps or a synthetic silo or chimney to prevent further fluid loss and cardiac desiccation and to provide soft tissue or synthetic protection of the exposed heart and any associated atrial diverticuli easily ruptured by minor trauma (4). In a 1982 report, Harrison et al. (2) immediately applied an adherent plastic drape over an intact omphalocele sac in a newborn with thoracoabdominal ectopia cordis. Progressive ligation of the plasticreinforced sac allowed the omphalocele contents to be gradually reduced by gravity and progressive replacement (2). After temporary coverage of the defect, diagnostic work-up can continue with cardiac catheterization and angiography. Following complete cardiac evaluation after temporary coverage of thoracoabdominal defects, Harrison et al. (2) recommended correction of intracardiac lesions before extensive reconstruction of the chest and abdominal wall, pericardium, and diaphragm. Such extensive op-

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CASE REPORTS

erations appear to be poorly tolerated in infants with giant omphaloceles and congenital heart defects (2). Intraoperative anesthetic management (cases 1 and 2) requires neuromuscular paralysis, controlled hyperventilation for respiratory acidosis, avoidance of high mean airway pressures that could impede biventricular outflows, high inspired 0, concentrations to improve blood and tissue oxygenation in cases characterized by low cardiac output syndrome and tissue ischemia, and avoidance of nitrous oxide which could distend bowel trapped in omphaloceles. In addition, the hemodynamic instability produced by heart and great vessel dissection contraindicates inhaled anesthetic agents that could promote further myocardial depression in neonates already compromised by extensive fluid losses from herniated viscera, and by respiratory and metabolic acidosis from alveolar hypoventilation and low cardiac output syndrome, respectively. Opiates and ketamine are often the only anesthetics that can be safely used. Extensive intraoperative monitoring is required, including direct blood pressure measurement by intraarterial cannulas and bladder catheterization for accurate urine outputs. Direct blood pressure measurement by right radial artery cannula is recommended as other arterial sites provide inaccurate blood gas measurements during reestablishment of transitional circulation, which often complicates the postoperative course in neonates with patent ductus awaiting later intracardiac repairs. A pulse oximeter probe on the right hand or right ear also provides continuous preductal monitoring of peripheral perfusion and tissue oxygenation. Although useful in directing massive volume replacement during thoracic dissection, central venous cannulation for right atrial pressure monitoring may be difficult or impossible because of atrial diverticuli and abnormal systemic and pulmonary venous drainage. Left atrial pressure monitoring may prove just as difficult or impossible for the same reasons. Needle atriotomy with a small-bore catheter through the needle will provide accurate intraoperative central venous pressure monitoring. Transthoracic right atrial cannulation may be helpful after staged repairs of ectopia cordis. Postoperatively, significant artifactual alterations will occur in right atrial waveforms during positive pressure ventilation in infants with either artificially covered or primarily repaired ectopic hearts because of cardiac compression and absence or instability of the anterior chest wall and diaphragm. To limit artifact, right atrial pressures should be measured only at end-exhalation without application of raised airway pressures. In the absence of supravalvular and branch pulmonary artery stenosis, a transthoracic pulmonary artery catheter may be inserted under direct vision through a right ventricular

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outflow tract ventriculotomy needle. The pulmonary artery catheter may permit better hemodynamic monitoring during low cardiac output states, persistent pulmonary hypertension, or prolonged pulmonary hypoplasia and allow for thermodilution cardiac output determinations postoperatively. As with right atrial pressures, pulmonary arterial pressures should be measured only at end-exhalation without application of raised airway pressures that could induce artifactual fluctuations in waveforms. Endotracheal tubes should remain in place until infants are conscious and vigorous with normal arterial blood gases, tidal volumes, and ventilatory mechanics, usually several days to weeks postoperatively (9). Tight skin or synthetic-silo closures of the thorax and abdominal wall can significantly restrict spontaneous ventilation and prolong the need for postoperative controlled ventilation (9). Tissue expanders create larger skin and subcutaneous tissue flaps for subsequent defect closures with less restriction of ventilation and may permit earlier tracheal extubation postoperatively (9). Cardiovascular failure, particularly from undiagnosed or uncorrected assoaated cardiac anomalies and rupture of cardiac diverticuli (1,7), and cardiorespiratory failure are frequent causes of death in the immediate postoperative period (Figure 1).Although never used in the management of ectopia cordis, extracorporeal membrane oxygenation may provide a better therapeutic bridge between defect coverage and later intracardiac or reconstructive surgery than inotropes alone. Further operations for wound dehiscence, secondary wound closures, or relaxing incisions may be necessary in the first few weeks postoperatively (1,7). Orthotopic heart transplantation has not been suggested as a viable alternative for the initial surgical management of ectopia cordis probably because associated chest and abdominal wall defects often need several staged repairs in an immunocompetent patient. After successful chest and abdominal wall closures, however, the infant with ectopia cordis and uncorrectable intracardiac defects may become a candidate for orthotopic heart transplantation, provided the recipient’s great vessel anatomy and pulmonary venous drainage are amenable to standard donorrecipient vascular anastomoses. In conclusion, the frequency of accurate in utero diagnosis of ectopia cordis is increasing. The extent of chest and abdominal wall deformities in ectopia cordis has often defied previous attempts at surgical repair. Extensive thoracic dissection to free the great vessels and to create more mediastinal space for a deformed heart that was later compressed by tight silo (case 1) or skin (case 2) closures led to the early postoperative death of patients 1 and 2, respectively, resulting from progressive intravascular volume

CASE REPORTS

losses, limitation of venous return, reduction of cardiac output, and pump failure. Prenatal sonographic diagnosis, abdominal delivery, neonatal resuscitation, and temporary and nonrestricting synthetic or skin coverage of thoracoabdominal defects may be followed by intracardiac repair and chest wall reconstruction in neonates with ectopia cordis. These efforts, combined with advances in surgical techniques, infant heart transplantation, and the newer cardiorespiratory support technologies, like extracorporeal membrane oxygenation, may soon improve the likelihood of quality survival in ectopia cordis.

References 1. Leca F, Thibert M, Khoury W, Fermont L, Laborde F, Dumez Y. Extrathoradc heart (ectopia cordis). Report of two cases and review of the literature. Int J Cardiol 1989;22:221-8.

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2. Harrison MR, Filly RA, Stanger P, de Lorimier AA. Prenatal diagnosis and management of omphalocele and ectopia cordis. J Pediatr Surg 1982;17:64-6. 3. Todros T, Presbitero P, Montemumo D, Levis F. Prenatal diagnosis of ectopia cordis. J Ultrasound Med 1984;3:Q9-31. 4. Kragt H, Aamoudse JG, Meyboom EJ, Laurini JL. Case report: prenatal ultrasonic diagnosis and management of ectopia cordis. Eur J Obstet Gynecol Reprod Biol 1985;20:177-80. 5. Klingensmith WC Ill, Cioffi-RaganDT, Harvey DE. Diagnosis of ectopia cordis in the second trimester. J CIin Ultrasound 1988; 16:204-6. 6. Haynor DR, Shuman WP, Brewer DK, et al. Imaging of fetal ectopia cordis: roles of sonography and computed tomography. J Ultrasound Med 1984;3257. 7. Dobell ARC, Williams HB, Long RW. Staged repair of ectopia cordis. J Pediatr Surg 1982;17:353-8. 8. Randolph J. Omphalocele and gastroschisis: different entities, similar therapeutic goals. South Med J 1982;75:1517-9. 9. Glass RB, Fembach SK. Case report: ectopia cordis and the radiographic changes of a new surgical repair. Clin Radio1 1987;38:4434.

Perioperative management of neonatal ectopia cordis: report of three cases.

Perioperative Management of Neonatal Ectopia Cordis: Report of Three Cases James H. Diaz, MD, MHA Departments of Anesthesiology and Pediatrics, Ochs...
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