Operative Correction and Postoperative Management of Transposition of the Great Vessels in Nine Children

Transcription

1 Operative Correction and Postoperative Management of Transposition of the Great Vessels in Nine Children J. Alex Haller, Jr., M.D., Crile Crisler, M.D., Robert Brawley, M.D., John Cameron, M.D., and Richard D. Rowe, M.D. D uring the past two years 9 children between the ages of 2 and 6 have had operative correction of transposition of the great vessels (Mustard procedure) [7] at The Johns Hopkins Hospital. Eight of the 9 had had Blalock-Hanlon procedures [3], and 1 a Rashkind procedure [S], in infancy. One patient died of progressive pulmonary insufficiency 12 days after operation. The others are living normal lives, and their activity is unrestricted. A discussion of the operative technique for correction of this anomaly and of postoperative management is the purpose of this report. INITIAL EVALUATION AND MANAGEMENT IN INFANCY In most infants with transposition of the great vessels, survival is dependent upon adequate intracardiac mixing. Generally, an atrial septal defect is better tolerated than is a large ventricular septal defect alone. A ventricular septal defect with associated pulmonary stenosis is also a favorable combination of defects [l 13. Immediate evaluation and management of these newborn infants has been greatly improved by application of newer techniques of cardiac catheterization, including cineangiography and retrograde arterial catheterization [9]. Our experience with palliative procedures for transposition of the great vessels was reported in 1966 [51. By far the most satisfactory procedure has been the creation of an atrial septal defect, as described by Blalock and Hanlon [3]. However, the initial mortality remains dis- From the Departments of Surgery and Pediatrics, The Johns Hopkins Hospital and University School of Medicine, Baltimore, Md. Supported in part by Consolidated Gifts for Heart and Transplantation Research. Presented at the Fifteenth Annual Meeting of the Southern Thoracic Surgical Association, San Juan, P.R., Nov , Address reprint requests to Dr. Haller, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Md THE ANNALS OF THORACIC SURGERY

2 Transposition of Great Vessels tressingly high in most medical centers [4, 51. Open procedures using inflow occlusion have generally given poor results, with several striking exceptions [6]. Eight of our 9 patients underwent Blalock-Hanlon procedures before they were 3 months old, and 5 required an operation or a Rashkind procedure during the first week of life. The Rashkind balloon procedure [8] has been vicariously championed by many cardiac surgeons because it obviates the necessity for a major thoracic operation in infants with respiratory distress. If the balloon successfully splits the valve of the foramen ovale, this procedure improves mixing and should be safer than a thoracotomy. So far the results are encouraging, but further evaluation is needed. One of our 9 patients had a Rashkind procedure at 2 days of age and showed dramatic improvement. In our clinic the Rashkind procedure is presently being attempted in all suitable patients, and surgical palliation is considered only if this procedure is unsuccessful. The exact role of banding the pulmonary artery in infants with transposition and excessive pulmonary blood flow remains undefined [12]. Although a small proportion of patients with intact ventricular septa may develop severe pulmonary vascular disease, pulmonary artery banding has usually been used for babies with large ventricular communications and persistent pulmonary hypertension. Banding should probably be reserved for infants with ventricular septal defects who develop progressive pulmonary hypertension. Surgical pulmonary stenosis may significantly complicate the eventual attempt to repair this anomaly. Pulmonary banding was not thought to be necessary in any of our patients; however, none of them had a ventricular septal defect. EVALUATION OF PATIENTS FOR TOTAL REPAIR OF TRANSPOSITION OF THE GREAT VESSELS Selection of patients for total repair of transposition may be difficult because of the complex nature of the intracardiac shunts and the difficulty of evaluating the pulmonary circulation. A number of criteria have been proposed for the selection of these patients [2, 41. It has become clear that the best operative results are achieved in patients with low pulmonary vascular resistance, minimal pulmonary outflow obstruction, and intact ventricular septa; however, patients meeting these criteria constitute a relatively small proportion of those with transposition. Therefore, the indications are slowly being expanded to include patients with small ventricular septal defects and moderate degrees of pulmonary stenosis. In our patients, the ventricular septa were intact and the pulmonary vascular resistance was normal. Two were thought to have moderate muscular pulmonary outflow obstruction. This group of patients, VOL. 7, No. 3, MARCH,

3 4 TABLE 1. MUSTARD REPAIR OF TRANSPOSITION Age, PV* Patient, Weight (kg.), Blalock- Rash- (mm. Preop. Patop. Op. Date & Hematocrit Hanlon kind Hg) Trach. Rhythm Rhythm Status W. J /65 M. P. 5/8/67 W. B D. W. 11 i2/67 J. W. 12/8/67 M. A. 3/6/68 M. C J. M. 5/21/68 T. M. 5/12/68 3?6,13,61 4?4,14,52 6,20,66 4,12,67 2%, 10,75 3%,15,62 6,24,54 6,15,60 3,11,69 8 weeks 7 days 11 weeks 7 days 3 weeks 12 days 2 days 3 days days No No NSRb Nodal 60; intermittent; NSR NSR Nodal 60 NSR Nodal 65; NSR after isoproterenol NSR Nodal 60 NSR NSR; nodal 65 NSR Coronary sinus rhythm NSR Nodal 100; NSR with exercise NSR NSR; nodal 70 NSR until 7 A-V dissociation mo. preop., 60; nodal 100 then nodal In school, not limited In school, active In school, full activity Died 12 days postop. of pneumonia. Intact repair. No limitation Full activity In school, full activity Full activity Full activity ~~ ~ PV = pulmonary ventricle pressure. bnsr = nodal sinus rhythm. N ~

4 Transposition of Great Vessels therefore, fits the criteria for ideal operative candidates (Table 1). No attempt was made to exclude patients with high hematocrits. Patients with growth cessation and marked exercise intolerance were operated upon as soon as these conditions were detected. The smallest child in our group weighed 10 kg., and his operative results have been satisfactory. We have been reluctant to operate upon smaller patients because of the tiny atria and the difficulties associated with cardiopulmonary bypass in small infants. OPERA TI VE TECHNIQUE In our first case, we followed closely the technique so beautifully described by Mustard [71. Continuous monitoring of the electrocardiogram was used during the repair. Radial artery and central venous cannulas were inserted and a median sternotomy incision was made. For cardiopulmonary bypass, systemic perfusion at a flow of 100 cc. per kilogram per minute with moderate hypothermia (30 to 32 C.) was accomplished by cannulation of the ascending aorta. The system was primed with either heparinized whole blood or equal volumes of Ringer's lactate solution and heparinized blood. The pericardium was removed from one phrenic nerve to the other and used for the intracardiac baffle. Initially, the systemic ventricle alone was vented; but, in the last 6 cases both ventricles were vented to improve exposure and facilitate removal of trapped air after completion of the repair. A bucket-handle atriotomy incision was made, leaving 1 cm. of atrium along each caval catheter to facilitate suturing of the pericardial patch. The entire remaining atrial septum was excised, and the coronary sinus was then incised into the left atrium. In 3 cases, the superior excision cut through the atrial wall, and repair of the resultant opening was necessary. The patient who had had a Rashkind procedure had the smallest atrial septal defect. A 2" x 3" pericardial patch was sutured in position using an anchoring stitch placed between the opening of the left atrial appendage and the left superior pulmonary vein. The pericardial suture line was continued posteriorly around the orifices of the pulmonary veins, as described by Mustard [71, to include these veins in a sleeve of pericardium. The suture lines were then carried anteriorly, covering the caval catheters and meeting in the septal wall. In this way total functional correction was achieved in all patients. In 3 cases, after the baffle was placed, the anterior (right) atrium was enlarged with a patch because the atrial chamber appeared too small. In 2 cases, pericardium was used for this patch, and in 1, knitted Teflon was employed. The first 4 patients developed a nodal rhythm which seemed to occur as the suture line was carried along the ridge between the coronary sinus and the tricuspid annulus. A-V dissociation has resulted from suturing in this area during repair of A-V canal and ostium primum defects. We therefore modified our method of opening the coronary sinus by extending the incision further into the left atrium, i.e., to within 1 cm. of the left inferior pulmonary vein (Fig. 1). It was then possible to keep the inferior suture line higher in the atrium and, therefore, a safer distance from the region of the A-V conduction system. In spite of this, conduction abnormalities developed in all but 1 patient in this series (Table 1). Aberdeen [l] has suggested that there are three major conduction pathways between the sino-atrial and atrioventricular nodes, two of which pass through the atrial septum. Thus, complete excision of the atrial septum may be responsible for the high incidence of nodal arrhythmias following the Mustard procedure. In our patients, however, these arrhythmias were well tolerated and did not necessitate permanent pacing or restriction of activity. Injury to the atrioven- VOL. 7, NO. 3, MARCH,

5 HALLER ET AL. FIG. I. Following complete excision of remaining interatrial septum, the ostium of the coronary sinus is opened into the left atrium; the incision is carried to the rim of the left inferior pulmonary vein. This maneuver assures drainage of coronary sinus blood into the proper ventricle and permits suturing of the pericardial baffle at n safe distance from the A-V node, as shown. tricular conduction system might result in a more serious arrhythmia which could require permanent pacing. The modification in technique described above obviates the need for sewing near the A-V node and provides a safeguard against injury to this tissue. In 2 of the first 4 patients, the prefashioned pericardial patch was too large and the redundant part obstructed pulmonary venous flow between the pulmonary veins and the tricuspid valve. In both cases a wedge was excised to correct this, and in 1 a patch was used to enlarge the right atrium. The latter patient died of pulmonary complications 12 days postoperatively. We felt that his initial poor response was due to pulmonary venous obstruction which, although corrected, may have left residual pulmonary damage. In the last 5 cases we have made no attempt to prejudge patch size but after completing the repair, using all of the pericardium, we have removed a central wedge to narrow the waist of the baffle and remove any obstruction to pulmonary-venous flow. This tailoring after repair is very simple and quite precise (Fig. 2). We believe it greatly simplifies the operation. When the patients were coming off cardiopulmonary bypass, it was often necessary to give them small doses of calcium chloride. Intravenous isoproterenol was also used frequently at a concentration of 2 pg/ml. This combination of drugs was very effective in supporting myocardial function. All patients were given digoxin in the operating room, and were subsequently digitalized to 40 pg. per kilogram of body weight in the Intensive Care Unit. Each patient had a myocardial pacing wire inserted, even in the presence 216 THE ANNALS OF THORACIC SURGERY

6 Transposition of Great Vessels FIG. 2. A large pericardial bafle is completely sutured in position for the Mustard repair. It is then tailored to remove the redundant tissue obstructing pulmonary venous drainage into the tricuspid valve. An appropriate wedge is excised as shown, and the opening is closed with a running suture. This modification avoids the ProSlem of prejudging an appropriate sire and shape for the pericardial patch. of a normal sinus rhythm. Chest tubes were left in both pleural spaces and in the anterior mediastinum. Two patients had significant postoperative bleeding requiring reexploration. In selected cases a Silastic catheter was left in a pulmonary vein for postoperative hemodynamic studies. POSTOPER A TI VE CARE Each patient was connected by endotracheal tube to a volume-controlled Emerson respirator+ using as low an intratracheal pressure as possible to give adequate ventilation. Oxygen was provided at a flow calculated to give a 35 to 40% oxygen concentration in the trachea initially; the flow was then reduced when adequate oxygenation could be maintained on room air. Generally, the lungs seemed more congested on x-ray than in comparable open-heart procedures, and pink secretions were commonly suctioned from the endotracheal tube during the first 12 to 18 hours postoperatively. Mechanical ventilation was used for 3 to 10 days. In all but Cases 7 and 9, a tracheostomy was necessary. We have been pleased with the new Dow Corning Silastic tracheostomy tubes,t which are pliable, nonreactive, and conform to the patient s tracheal curve. By using these tubes and securing the respirator tubes to the chest, a child may move his head without endangering the connection, and there is less danger of trauma to the tracheal wall (Fig. 3). All Silastic tubes were removed without weaning to smaller sizes and without tracheal stenosis [lo]. We *J. H. Emerson Company, Cambridge, Mass. TSilastic Tracheostomy Tubes (Aberdeen Design), Dow Corning Corporation, Midland, Mich. VOL. 7, NO. 3, MARCH,

7 HALLER ET AL. FIG. 3. Child with Silastic tracheostomy tube attached to respirator. Note freedorn of head and ease of management. do not know why we were able to avoid tracheostomy in the 2 most recent patients. Their endotracheal tubes were left in for 1 and 3 days, respectively, and they were then able to breathe without further support. Six patients were paced for 2 to 10 days postoperatively using the myocardial electrodes. All of them had slow nodal rhythms. No complete heart block or idioventricular rhythm was noted, and none of these patients has required a permanent pacemaker. The wires were removed after 10 to 14 days, except in the last patient, who removed his own wires and did well in spite of a rate of 60 beats per minute. It is interesting that most, if not all, of the patients with nodal rhythms have episodes of normal sinus rhythm with exercise. For the present our observations suggest that these nodal rhythms are not fixed conduction defects but are preferential conduction pathways. In most patients some degree of peripheral vasoconstriction was present upon return to the Intensive Care Unit. This was manifested by cool, pale extremities with collapsed veins, and a normal rectal temperature. In many of these patients the central venous pressure was normal, and there was a very low urinary output. This peripheral vasoconstriction was usually accompanied by moderate metabolic ;icidosis, which was compensated for by intentional hyperventilation to a ph of 7.45 to The signs of poor peripheral perfusion and vasoconstriction were reversed by isoproterenol (Isuprel) when a slow cardiac rate permitted its use, or by chlorpromazine when a tachycardia was present. The vasodilating effect of these drugs was not alone sufficient to correct the problem. Blood transfusion was required and it was often necessary to elevate the central venous pressure to the range of 18 to 22 cm. of water to achieve adequate peripheral circulation. For example, a patient weighing 11 kg., with an estimated blood volume of approximately 1000 cc., had a central venous pressure of 10 cm. of water but was severely vasoconstricted and oliguric. After administering a vasodilator, 400 cc. of whole blood was given. Following this transfusion of almost one-half the patient s blood volume, central venous pressure and systemic atrial pressures were unchanged at 10 to 12 cm. of water, the peripheral veins filled, the skin became warm, and the urine output rose to 50 to 60 cc. per hour (Fig. 4). Postoperative peripheral vasoconstriction in the face of normal central venous pressure is seen after a variety of intracardiac procedures, and we know 218 THE ANNALS OF THORACIC SURGERY

8 Transposition of Great Vessels PRESSURE cm. HeO I00 cc. WHOLE BLOODGIVEN 300 cc. WHOLE BLOOD GlVEN TRANSFUSION COMPLETED R.A Ma MINUTES I I HOUR A B C FIG. 4. Composite atrial pressure recording showing equal response of both atria to transfusion of nearly one-half the patient s blood volume after administration of potent vasodilator (isoproterenol). Dramatic improvement in patient s peripheral circulation was noted. of no satisfactory explanation for it. We do know, however, that unless it is aggressively reversed, profound metabolic acidosis rapidly develops. In the patient with transposition, a sudden change of the pulmonary venous pool to a systemic but anatomical right ventricle, and the systemic venous pool to a pulmonary but anatomical left ventricle may contribute to these changes and necessitate a high venous filling pressure. SUMMARY Nine children between the ages of 2 and 6, weighing 10 to 24 kg., have had operative correction of transposition of the great vessels at The Johns Hopkins Hospital during the last two years. Two modifications in our operative technique have simplified the Mustard procedure, and these technical details are discussed. Most of the patients have required temporary myocardial pacing, but none has required a permanent pacemaker. More than half the patients have persistent nodal rhythms, but they seem to tolerate the arrhythmia well and have not required any limitation of activity. Seven of the 9 patients required temporary tracheostomy to permit adequate pulmonary toilette and respiratory support. The newer Silastic tracheostomy tubes were used in these patients and were entirely satisfactory. An inappropriate vasoconstriction and secondary metabolic acidosis were quite common in the immediate postoperative period. This responded in all cases to vasodilatation induced with chlorpromazine or isoproterenol plus aug- VOL. 7, NO. 3, MARCH,

9 HALLER ET AL. mentation of the blood volume. One patient died of progressive pulmonary insufficiency 12 days after operation. The others are living normal lives. REFERENCES 1. Aberdeen, E. Presented as part of the Cardiovascular Postgraduate Course of the American College of Surgeons, October, Aberdeen, E., et a1 Successful correction of transposed great arteries by Mustard s operation. Lancet 1 :233, Blalock, A., and Hanlon, C. R. Surgical treatment of complete transposition of aorta and pulmonary artery. Surg. Gynec. Obstet. 90:1, Cooley, D. A., Hallman, G. L., Bloodwell, R. D., and Leachman, R. D. Twostage surgical treatment of complete transposition of the great vessels. Arch. Surg. (Chicago) 93:704, Cornell, W. P., Maxwell, R. E., Haller, J. A., and Sabiston, D. C. Results of the Blalock-Hanlon operation in 90 patients with transposition of the great vessels. J. Thorac. Cardiovasc. Surg. 52:525, Lindesmith, G. G., Meyer, B. W., Jones, J. C., and Gallaher, M. E. Palliative procedure for treatment of transposition of the great vessels. CircuZation 316uppl. 1):21, Mustard, W. T., Keith, J. D., Trusler, G. A., Fowler, R., and Kidd, L. The surgical management of transposition of the great vessels. J. Thoruc. Curdiovusc. Surg. 48~953, Rashkind, W. J., and Miller, W. W. Creation of an atrial septa1 defect without thoracotomy: A palliative approach to complete transposition of the great arteries. J.A.M.A. 196:991, Rowe, R., and Mehrizi, A. The Neonate with Congenital Heart Disease. Vol. V of Major Problems in Clinical Pediatrics. Philadelphia: W. B. Saunders, Talbert, J. L., and Haller, J. A. Improved Silastic tracheostomy tubes for infants and young children. Pediat. Surg. 3:408, Toole, A. L., Glenn, W. W. L., Fisher, W. H., Whittemore, R., Ordway, N. K., and Bidone, R. A. Operative approach to transposition of the great vessels. I. Classification and review of 32 cases with and 40 cases withoul operation. Surgery 48:43, Trusler, G. A., and Mustard, W. T. Selection of palliative procedures in transposition of the great vessels. Ann. Thorac. Surg. 5:528, THE ANNALS OF THORACIC SURGERY