Left Ventricular Diverticulum

Transcription

1 The Surgical Treatment of a Syndrome Consisting of Thoracoabdominal Wall; Diaphragmatic, Pericardial, and Ventricular Septa1 Defects; and a Left Ventricular Diverticulum D. Alton Murphy, M.D., Eoin Aberdeen, F.R.C.S., R. H. Dobbs, F.R.C.P., and D. J. Waterston, F.R.C.S. M ultiple congenital anomalies consisting of defects in the upper abdominal wall, lower sternum, anterior diaphragm, diaphragmatic pericardium, and ventricular septum, and a left ventricular diverticulum have been successfully repaired in one operation on 3 previous occasions [lo]. One other case has been reported in which the repair was staged, closing the ventricular septa1 defect first, followed later by a diverticulectomy [ 131. The following communication reports the fourth successful total correction of this syndrome as a single procedure and discusses its surgical management and embryogenesis. CASE HISTORY The patient was first seen at the age of 4 weeks. The mother s only complaints were that the infant was a slow feeder and had a large epigastric hernia. Within the hernia was a pulsatile mass, which on compression caused marked sinus bradycardia. The appearance of the hernia at 1 year of age is shown in Fig. 1. She was first admitted to the Hospital for Sick Children, London, in 1962 for cardiac investigation. In 1967, at the age of 11 years, she was admitted for surgical correction of her defects. She had had no limitation of activity but had remained below the third percentile for height and weight. PHYSICAL EXAMINATION She was a small, well-nourished 11-year-old girl in no distress. The abnormal physical findings were limited to the epigastrium and cardiovascular system. The midline epigastric hernia had decreased in size (Fig. 2) and measured 7 x 15 cm. The visceral contents were easily reducible. The skin over the hernia was thin, From the Thoracic Unit, Hospital for Sick Children, Great Ormond Street, London, England. Accepted for publication June 17, Address reprint requests to Dr. Murphy, Department of Surgery, Montreal Children s Hospital, Montreal, P.Q., Canada. 528 THE ANNALS OF THORACIC SURGERY

2 Multiple Thoracoabdominal Defects FIG. 1. The patient at 1 year of age. FIG. 2. The patient at 11 years of age. wrinkled, and hyperpigmented. There was a wide diastasis recti above the umbilicus. There was an absence of the lower sternum, and protruding from this area was an ellipsoid pulsatile mass. There was no digital clubbing or cyanosis. Radial pulses were equal and regular, and the blood pressure was 85/60 mm. Hg. There was a mild right ventricular heave. Apex beat was in the left midclavicular line at the fifth interspace. There was a grade 2 (grading 1 to 6) systolic thrill along the mid-left sternal border. No thrill was palpable over the pulsatile mass. The pulmonic second sound was loud and closely split. There was a grade 4 pansystolic murmur along the left sternal border at the third and fourth interspaces; there was also a grade 3 mid diastolic murmur at the apex. There was no evidence of congestive heart failure. The electrocardiogram showed left axis deviation of -60 degrees and evidence of left bundle-branch block in leads I, 11, AVR, AVL, V4R, and V1. There were prominent Q waves in leads I and I1 and in the left precordial leads. The chest x-ray demonstrated a prominent pulmonary artery and increased pulmonary vascular markings. The heart was not enlarged, and the lower border of the cardiac shadow did not appear abnormal. Cardiac Catheterization. Blood sampling (Table 1) showed a step-up in oxygen saturation between the right atrium and the right ventricle, indicating a large left-to-right shunt at the ventricular level. The ratio of pulmonary to systemic flow was greater than 3 : 1. The main pulmonary artery pressure was almost equal to systemic pressure. The pulmonary vascular resistance was onequarter to one-fifth of the systemic resistance. The pulsatile mass was demonstrated to be a large left ventricular diverticulum, extending into the hernia. There was no pressure gradient between it and the left ventricle. SURGERY The heart and diverticulum were exposed through a median sternotomy incision. The diverticulum measured 8 x 5 cm. Its blood supply was mainly from terminal branches of the left internal mammary and left inferior epigastric arteries (Fig. 3). There was an anterior oval midline defect in the diaphragm and VOL. 6, NO. 6, DEC.,

3 MURPHY ET AL. TABLE 1. Site Superior vena cava Inferior vena cava Right atrium Right ventricle Main pulmonary artery Left atrium Left ventricle Aorta RIGHT- AND LEFT-HEART CATHETERIZATION DATA Blood Pressure" (mm. Hg) a = 6, v = 5 (4) (52) a = 12, v = 20 (11) 76lOlQ (75) Oxygen Saturation (%) *Figures in parentheses indicate mean pressure; figures underlined indicate end-diastolic ventricular pressure. adjacent pericardium, through which the diverticulum protruded. There was no pericardial covering for the diverticulum. Dense adhesions were present between the diverticulum and adjacent subcutaneous fat anteriorly, and there was a thin, fibrous extension of the diaphragm posteriorly. The adhesions obliterated the pericardial cavity and extended into the superior mediastinurn, where they became very dense. Numerous technical obstacles were encountered in getting the patient onto cardiopulmonary bypass. The heart was rotated on its axis to the right, which made the small right atrium difficult to expose from the median sternotomy. The adhesions complicated this problem further. The root of the aorta was rotated well posteriorly, which made it unsafe to use this vessel for the arterial inflow line. The left external iliac artery was exposed. Unfortunately, the external iliac artery was small and thrombosed, having been used for cardiac investigation. The right external iliac artery also had been used recently for cardiac catheterization. The epigastric hernia was opened widely, and the inflow line was then placed in the abdominal aorta below the origin of the superior mesenteric artery. The caval vessels were inaccessible, so that partial bypass was begun using a right FIG. 3. Diagram of the blood supply to the diverticulum. 530 THE ANNALS OF THORACIC SURGERY

4 Multiple Thoracoabdominal Defects.Marlex mesh A FIG. 4. (Left) Repair of the diaphragm and diastasis recti. (Right) Repair of residual sternal and epigastric defect. B ventricular vent; the patient was cooled to 24 C. Total cardiopulmonary bypass was then achieved by dissecting some of the right atrium from the surrounding adhesions and then placing two separate caval cannulas. The right ventriculotomy was enlarged to expose a large (5 x 3 cm.) subaortic ventricular septa1 defect, which was patched with two-way stretch Dacron. The apex of the diverticulum was opened, and, with the finger inserted into the lumen, the normal left ventricular cavity could be easily identified and the diverticulum excised. Both ventriculotomies were closed with 3-0 silk. The defect in the diaphragm was closed using adjacent diaphragmatic muscle and fascia and attaching it to the undersurface of the reapproximated sternum (Fig. 4A). The epigastric hernia was repaired by bringing the widely separated rectus muscles together (Fig. 4B) with interrupted Tensofil" sutures. The residual diamond-shaped defect was bridged with a single layer of fine Marlex mesh. The only late operative complication was persistent hemorrhage caused by residual heparin, which was finally controlled with further protamine and transfusions of fresh blood. This extended the total operation time to 14 hours. Her subsequent course was uneventful, and she is now in good health and back at school. DISCUSSION There are 57 cases of this syndrome now recorded in the literature [l, 2, 6-9, 12, 131. The consistent features are: absence of the lower sternum; diastasis recti with lateral insertion of the rectus muscles onto the lower costal cartilages; epigastric hernia, which may present as an omphalocele in the newborn; anterior diaphragmatic with adjacent pericardial defects; and cardiac abnormalities. *R. Graf & Co., Nuremberg, West Germany. VOL. 6, NO. 6, DEC.,

5 MURPHY ET AL. This group of congenital malformations was first described as a syndrome by Cantrell, Haller, and Ravitch [l]. Previous authors have reported the obvious defects-the ventricular diverticulum or the palpable heart in the epigastrium-regarding them as a subgroup of ectopia cordis. As the general relationships of the heart to the other thoracic vicera are normal, this group of malformations should not be classified as ectopia cordis [l]. The cardiac defects have varied widely. Where complete reports are available, a ventricular septa1 defect has occurred in 78% of cases. These occurred as isolated defects or as one of a complex of cardiac defects, Fallot s anomaly being the commonest. A left ventricular diverticulum was found in 67% of the cases, varying in size and shape from small, tubular structures several millimeters in diameter to large, sac-shaped diverticula up to 8 cm. long and 5 cm. in diameter (present case). Dextrorotation of the heart is a common feature. Symptoms arising from this syndrome are related more to the type of cardiac defect than to the other malformations. The cardiac lesions have been a predisposing or a direct cause of death in most cases. The diverticulum has caused death by rupture in only one case [16], and it is possible that this was a left ventricular aneurysm and not a diverticulum. Rupture of an isolated left ventricular diverticulum has been reported [5, 151, but the pathology of these diverticula was quite different from that associated with this syndrome. The surgical repair of the extracardiac lesions has been thoroughly discussed by previous authors [l, 7, 101. Suffice it to state that providing no omphalocele is present, there is no urgency to repair the defects. The ease with which repair can be done at an early age, however, is important, and early repair is advocated [l]. The management of the cardiac lesions should not be influenced by the extracardiac defects. Palliative and corrective surgery should be done as required. Complete repair can be performed at one time; however, the clinical situation may favor a staged repair [13], repairing the intracardiac defect first, followed later by diverticulectomy. Diverticulectomy alone has been associated with fatal arrhythmias [9]. Cardiopulmonary bypass may be complicated by the dextrorotation of the heart, which in this case prevented safe access to either of the venae cavae or the ascending aorta. EMBRYOLOGY The diaphragmatic and pericardial defects probably result from a developmental failure of a segment of the septum transversum. A failure of complete migration of the paired primordial mesodermal portions, which form the sternum and paramedian abdominal wall, would account for defects in these structures [l]. The origins of the diverticulum and the dextrorotation of the heart, which are constant features, 532 THE ANNALS OF THORACIC SURGERY

6 Multiple Thoracoabdominal Defects have not been adequately explained. Mustard et al. [ll] suggested that the diverticulum is due to a simple herniation of the heart wall at its thinnest part; once formed, it presses on the diaphragm, causing it to thin out or perforate and leading to protrusion into the anterior abdominal wall. The primary abnormality postulated by Potts [14] is a result of a fusion of the epimyocardium with the septum transversum. As the latter descends, a diverticulum involving all layers of the myocardium is formed. Dextrorotation with levocardia in the full-term fetus can be due either to an excessive dextrorotation of the primary heart tube at the 10- to 20-somite stage or to a failure to undergo left counterclockwise rotation at the end of the first fetal month. Growth of the trabeculated area of the primary heart tube is vastly greater than of the nontrabeculated regions [8]. If excessive growth of the left ventricular anlage occurred at a stage when trabeculation was beginning (third week of life, when the fetus is barely 2 mm. in length), then this might be responsible for the exaggerated dextrorotation of the heart. Dorsal invagination of the septum transversum and adjacent pericardial mesoderm which occurs at this time would then be impeded by the left ventricular myocardium, and defects in the former structures would occur. Molding of the left ventricular epimyocardium by the developing septum transversum could account for the wide variability in the shape or even presence of the diverticula reported in adult life. The presence of the diverticulum would also prevent normal leftward rotation of the heart at the end of the first fetal month. The altered hemodynamic forces occurring from such an event might also account for the defective ventricular partitioning and other cardiac defects frequently observed in this syndrome. SUMMARY A patient with congenital anomalies consisting of diaphragmatic, pericardial, and lower sternal defects; epigastric hernia; left ventricular diverticulum; and a ventricular septal defect is reported. Successful correction of these defects was performed at 11 years of age. Cardiopulmonary bypass was complicated by cardiac dextrorotation, which prevented safe access to the cavae and the aorta. The surgical management and the embryology of these defects are discussed. ADDENDUM Since the manuscript was submitted, another patient, aged 2 months, was admitted to the Hospital for Sick Children with this syndrome. The cardiac defects consisted of left ventricular diverticulum, ventricular septal defect, left pulmonary artery stenosis, partial anomalous pulmonary venous drainage, and persistent left superior vena cava. VOL. 6, NO. 6, DEC.,

7 MURPHY ET AL. REFERENCES 1. Cantrell, J. R., Haller, J. A., and Ravitch, M. M. A syndrome of congenital defects involving the abdominal wall, sternum, diaphragm, pericardium and heart. Surg. Gynec. Obstet. 107:602, Crittenden, I. H., Adams, F. H., and Mulder, D. G. A syndrome featuring defects of the heart, sternum, diaphragm and anterior abdominal wall. Circulation 20:396, De Haan, R. L. Development of form in the embryonic heart. Circulation 35:821, de Vries, P. A., Saunders, J. B. dc. M. Development of the ventricles and spiral outflow tract in the human heart. Carnegie Inst. Wash. Contrib. Embryol. 37:87, Drenna, M. R., and van der Vijver, G. T. Diverticulum of the human heart. J. Med. Ass. S. Afr. 2:58, El-Akkari, E. S., El-Din, M. K. B., and Kassem, A. S. Diverticulum of the left ventricle. Arch. Dis. Child. 40:545, Eraklis, A. J., Trump, D. S., and Longino, L. A. Omphalocele with diaphragmatic and pericardial defects: Diagnosis and repair. J. Pediat. Surg. 2354, Grant, R. P. The embryology of ventricular flow pathways in man. Circulation 25:756, Kallfelz, H. C., Luster, G., and Schafer, H. Herzwanddovertikel, und Fallotsche pentalogie. Arch. Kreislaufforsch. 50:271, Mulder, D. G., Crittenden, I. H., and Adams, F. H. Complete repair of a syndrome of congenital defects involving the abdominal wall, sternum, diaphragm, pericardium and heart. Ann. Surg. 151: 113, Mustard, W. T., Duckworth, J. W. A., Rowe, R. D., and Dolan, F. G. Congenital diverticulum of the left ventricle of the heart. Canad. J. Surg. 1:149, Ongley, P. A., Titus, J. L., Brown, R., and Kincaid, 0. W. Partial ectopia cordis simulating tricuspid atresia. Mayo Clin. Proc. 40:513, Perez-Alvarez, J. J., Perez-Trevino, C., and Flor, R. D. Successful total correction of ventricular septa1 defect, diverticulum of the left ventricle, and anomaly of the thoracoabdominal wall in an 11 year old boy with cardiac dextroversion. J. Thorac. Cardiovasc. Surg. 52: 386, Potts, W. J., DeBoer, A., and Johnson, F. R. Congenital diverticulum of the left ventricle. Surgery 33:301, Swyer, A. J., Mauss, I. H., and Rosenblatt, P. Congenital diverticulosis of the left ventricle. Arner. J. Dis. Child. 79:111, Sydow, V. Rupture des herzens bei einem kindle. Jahrb. Kinderh. 47:437, THE ANNALS OF THORACIC SURGERY