Does the modified Blalock-Taussig shunt cause growth of the contralateral pulmonary artery?

BACKGROUND: Although some pediatric cardiology departments have a policy of adopting primary correction of tetralogy of Fallot in all symptomatic infants, we and others still palliate neonates and infants. Effective palliation should ameliorate symptoms and allow growth of the pulmonary arteries. Although studies on the growth of the ipsilateral and contralateral pulmonary arteries after a classic Blalock-Taussig shunt have been reported, pulmonary artery growth after a modified Blalock-Taussig shunt has not been studied as thoroughly. Therefore, we examined whether there is equal growth of the contralateral pulmonary artery after a modified Blalock-Taussig shunt. METHODS: We retrospectively analyzed the records of 140 patients with symptomatic tetralogy of Fallot who had a modified Blalock-Taussig shunt between October 1985 and October 1995. The median age at the time of the Blalock-Taussig shunt was 1.6 months. All patients had corrective procedures at a median age of 1.7 years. Cineangiography was done before the corrective procedure. From the angiograms the diameter of the right and left pulmonary arteries before their first lobar branches and the diameter of the descending thoracic aorta at the level of the diaphragm were measured. For each patient the ratios of right pulmonary artery to descending thoracic aorta and left pulmonary artery to descending thoracic aorta were determined and compared using Student's t test. RESULTS: Of the 140 patients, 114 had a left-sided Blalock-Taussig shunt, 20 had a right-sided shunt, and 6 patients had bilateral shunts. The mean right pulmonary artery to descending thoracic aorta ratio was 1.10 and the mean left pulmonary artery to descending thoracic aorta ratio was 0.98. This difference was not significant. CONCLUSION: We showed equal growth of the right and left pulmonary arteries with no distortion after a modified Blalock-Taussig shunt. If palliation is considered, the modified Blalock-Taussig shunt remains our choice.     

A case of a patient with the non-confluent main pulmonary artery with the left pulmonary artery after a left Blalock-Taussig shunt for tetralogy of Fallot, which underwent a successful two staged radical repair

We report on a 14-year-old girl with tetralogy of Fallot and the non-confluent main pulmonary artery with the left pulmonary artery after a left Blalock-Taussig shunt. She underwent a left-sided classic Blalock-Taussig shunt at the age of one. However, she showed repeated dyspnea and increasing cyanosis, and cardioangiography showed the non-confluent main pulmonary artery with the left pulmonary artery. Corrective surgery of tetralogy of Fallot was done by a two-staged operation. In the first stage, a EPTFE prosthesis was grafted between the main pulmonary artery and the left pulmonary artery, and in the second stage, intracardiac operation was performed. The late postoperative status and hemodynamic results were satisfactory and we emphasize the rational for this approach.     

Total cavopulmonary connection for grown diminutive pulmonary artery after staged Blalock-Taussig shunt

We report a two-year-old girl with asplenia, {A, L, L} DORV, pulmonary atresia, common AV valve, PDA, and TAPVC, who successfully underwent total cavo pulmonary connection (TCPC). Deep cyanosis was pointed out since birth. Cardiac catheterization performed on the sixth day after birth revealed a diminutive pulmonary artery tree of which PA index was 41 mm²/m². Left modified Blalock-Taussig shunt was created at 27 days of age. The PA index increased to 282 mm²/mm², but disparity in diameter between the left and the right pulmonary artery was yielded by PDA subsidence. Therefore additional contralateral B-T shunt was made at one year of age. Follow-up cardiac catheterization at 28 months of age showed well developed pulmonary artery; PA index of 460 mm²/m², right pulmonary resistance (Rp) of 3.49 units, left Rp of 2.33 units, and estimated total Rp was 1.39. According to study, bidirectional Glenn procedure or TCPC was indicated. Considering neccesity of urgent repair of common pulmonary vein obstruction, regurgitation of the common atrio-ventricular valve and pulmonary artery stenosis, TCPC was performed with concomitant repair of the associated lesions. Severe butterfly-figure stenosis of the central PA was augmented by anastomosing both the left SVC and the left-sided atrium. In conclusion, diminutive pulmonary artery could be adequately grown by phase-in Blalock-Taussig shunts. Pulmonary blood flow scintigraphy was thought to be useful for estimation of pulmonary resistance in such cases with different pulmonary resistance between right and left PA.     

Repair of tetralogy of Fallot with obstruction of right pulmonary artery; report of a case

Patients with tetralogy of Fallot showing unilateral obstruction of a pulmonary artery, especially the right pulmonary artery, are a high-risk group for pulmonary hypertension after repair. This case of tetralogy of Fallot with the obstruction of the right pulmonary artery received a Blalock-Taussig shunt at 7 months old, and the occluded right pulmonary artery caused empyema after surgery. At 2 years old, a cardiac catheter study showed a pulmonary artery index of 193.6 mm2/m2, so we undertook intracardiac repair. After the repair, she showed a relativery favorable clinical course. Systolic pulmonary artery pressure and right ventricular pressure were about 30 and 50 mmHg, respectively. We considered that tetralogy of Fallot with obstruction of right pulmonary artery could be repaired, as long as the pulmonary artery index was within the limits of indication and the left ventricle was well-developed.     

Reoperation of Blalock-Taussig shunt for double outlet right ventricle and pulmonary atresia in an adult

A 36-year-old man was admitted to our hospital due to dyspnea and pneumonia. He had undergone left classical Blalock-Taussig shunt at 5 years old and right modified Blalock-Taussig shunt at 16 years old, because he was judged as no indication for any radical operation. Since the last surgery, he had stopped visiting hospital. Computed tomography showed pneumonia and pulmonary embolism in the left lower lung and occlusion of the right modified Blalock-Taussig shunt. After pneumonia was improved by antibiotic treatment, he underwent reoperation of the right modified Blalock-Taussig shunt using 8 mm knitted Dacron graft. Postoperative course was uneventful and dyspnea and cyanosys were improved. We successfully treated a complicated case of an adult congenital heart disease by reoperation of the right modified Blalock-Taussig shunt.     

Systemic-pulmonary shunts in infants and children. Early and late results

From September, 1978, to January, 1983, 44 cyanotic infants and children underwent a systemic-pulmonary artery shunt for the treatment of reduced pulmonary blood flow. Age ranged from 18 hours to 4 years (mean age = 0.49 years). Weight ranged from 1.7 kg to 13.2 kg (mean weight = 4.9 kg). There were 12 classic Blalock-Taussig shunts, five central polytetrafluoroethylene shunts, six interposition modified Blalock-Taussig shunts, and 21 Great Ormond Street type of modified Blalock-Taussig shunts. No direct aorta-pulmonary artery anastomoses were performed. There was one postoperative death (1/44 = 2.3%) in a 1,700 gm neonate born with pulmonary atresia and intact ventricular septum (shunt patent). Four shunts required early revision: one thrombosed central shunt, a kinked patent interposition Blalock-Taussig shunt, a small but patent Blalock-Taussig shunt, and one excessive Great Ormond Street type of Blalock-Taussig shunt. Two late deaths were probably shunt-related: one Blalock-Taussig and one central. All four types of shunts provided good palliation, but the Great Ormond Street type of Blalock-Taussig shunt is our preferred shunt because of (1) low operative risk, (2) predictable patency (100% in our series), (3) lack of distortion of pulmonary arterial anatomy, and (4) technical ease of insertion as well as takedown.     

Autogenous pericardial patch augmentation of the anastomotic orifice of Blalock-Taussig shunt]

Our recent experiences of the autogenous pericardial patch augmentation of Blalock-Taussig anastomotic orifice are reported. In Case 1, the direct suture between the left subclavian artery and the left pulmonary artery was difficult on the anterior wall because of the shortness of the left subclavian artery. Therefore, a piece of the patient's own pericardium was excised and sutured anteriorly between the two vessels by interrupted 7-0 polypropylene sutures. A 19 months postoperative angiogram showed so-called parrot-beaking of the subclavian artery probably due to tension, but there was no distortion or stenosis of the pulmonary artery. In Case 2, the right subclavian artery distal to the bifurcation of the vertebral artery was longitudinally split measuring approximately 2.5 cm in length, and widened by a piece of the autogenous pericardium in a wedge shape. Then, it was anastomosed to the right pulmonary artery without undue tension. Seven months postoperatively the patient died from severe AV valve regurgitation. The autopsy showed widely patent anastomosis and good healing as well as slight expansion of the pericardial patch but without aneurysm formation. In Case 3, the same operation as in Case 2 was performed. A 6 months postoperative angiogram showed no stenosis or distortion of either the subclavian or the pulmonary artery. Although it is premature to draw any conclusion, the use of the autogenous pericardium may be indicated to widen the anastomotic orifice of Blalock-Taussig shunt without sacrificing the length of the subclavian artery even in small infants or neonates.     

An unusual post-operative complication following modified left Blalock-Taussig shunt

A left modified Blalock-Taussig shunt was performed in a 3-year old child with Fallot's tetralogy. Intraoperative course was uneventful. Persistent hypoxia was noticed in the post-operative period in spite of a clinically functioning shunt. Angiography revealed a functioning shunt with totally blocked left pulmonary artery. A thrombus was removed from the left pulmonary artery which dramatically improved the clinical course of the patient.     

Experience with the Norwood procedure without circulatory arrest.

OBJECTIVE: We evaluated a new cardiopulmonary bypass technique that allowed complete avoidance of circulatory arrest and deep hypothermia in the Norwood procedure for hypoplastic left heart syndrome. METHODS: A total of 10 patients were included in this study. The arterial line of the cardiopulmonary bypass circuit was divided in two in a Y shape; one branch was used for cerebral perfusion through the innominate artery and the other for lower body perfusion through the cannula inserted into the descending thoracic aorta. Moderate hypothermia (29 degrees C-31 degrees C rectal temperature) and high pump flow (150-180 mL. kg(-1). min(-1)) were used. A valveless conduit between the right ventricle and the pulmonary artery was used in 6 patients as an alternative pulmonary blood source to a conventional Blalock-Taussig shunt (n = 4). RESULTS: Circulatory arrest was completely avoided throughout the operation in all cases, and no complications from the new cardiopulmonary bypass technique were seen. Early deaths occurred in 3 cases. Neurologic deficits were not seen among the survivors, and the postoperative course was stable and uneventful, including satisfactory renal function. CONCLUSIONS: The Norwood procedure for hypoplastic left heart syndrome was successfully accomplished with complete avoidance of circulatory arrest by means of cerebral perfusion through the innominate artery combined with cannulation of the descending aorta. A conduit between the right ventricle and the pulmonary artery seems an excellent alternative pulmonary blood source, although right ventricular function needs to be carefully monitored.     

Systemic-pulmonary artery anastomoses in infancy.

Over the last 10 years, 142 systemic-pulmonary artery anastomoses were performed in 134 infants under 1 year of age. These included shunts from the subclavian artery (46 per cent), ascending aorta (41 per cent), descending aorta (9 per cent), and superior vena cava (1 per cent) to the pulmonary artery. Ninety-six (72 per cent) of the infants were less than 4 months of age at the time of the initial procedure, and one half were less than 1 month old. When groups of patients were compared according to diagnosis and age at the time of operation, the immediate and long-term results of the subclavian-pulmonary artery (Blalock-Taussig) anastomosis were better than the results with the other procedures. In view of the ease of closure of this anastomosis at the time of corrective surgery, as well as the recent further improvement of vascular surgical techniques, the Blalock-Taussig shunt is the procedure of choice in most infants requiring a systemic-pulmonary artery anastomosis, even during the early months of life.     

Stent-graft repair of an aortic rupture caused by invasive hemangiopericytoma

A 2.6 kg female with the diagnosis of type "B" interruption of the "right" aortic arch and mitral atresia underwent stage I palliation with translocation and anastomosis of the distal right carotid artery to the descending aorta. The distal main pulmonary artery was anastomosed to the under surface of the neoaortic arch. A modified Blalock-Taussig shunt was constructed between the left side innominate artery and the left pulmonary artery. The child awaits stage II palliation.     

Anomalous Origin of the Right Pulmonary Artery from the Ascending Aorta: A Surgical Case Study in an Adult Patient with "Irreversible" Pulmonary Vascular Disease

Abstract   An adult patient presented with an anomalous right pulmonary artery arising from the ascending aorta with severe unilateral pulmonary vascular disease of the left lung due to a large left-sided patent ductus arteriosus. A stenosis in the right pulmonary artery protected the right pulmonary vasculature. Right ventricular pressure was suprasystemic. After ductal ligation and surgical repair, pulmonary artery pressures fell dramatically. An immediate postoperative angiography confirmed extremely poor perfusion of the left lung. At four-and-a-half years of follow-up, the patient's quality of life had improved dramatically, main pulmonary artery pressure was one-sixth of systemic pressures, and there was vastly improved perfusion of the left lung at this lower perfusion pressure. The calculated pulmonary vascular resistance of the left lung was within normal limits. These findings suggested a significant degree of reversal of pulmonary hypertensive disease in the left lung sustained to 54 months postoperatively.     

One-stage unifocalization followed by staged Fontan operation

We report a successful case of staged Fontan operation for single ventricle, pulmonary atresia, major aortopulmonary collaterals and absent central pulmonary artery. The one-stage unifocalization, concomitant with central pulmonary artery creation by autologous pericardium and modified Blalock-Taussig shunt at 1 month of age as the first palliation, and the Glenn operation and pulmonary arterial augmentation with superior vena caval patch at 9 months of age as the second palliation were performed. Extracardiac conduit Fontan operation was completed at 22 months of age. The pulmonary artery continued developing with increasing pulmonary arterial index and stable pulmonary arterial pressure throughout the clinical course. The one-stage unifocalization in early infancy and the repeated surgical intervention to the pulmonary artery without prosthetic material provided excellent pulmonary arterial growth and Fontan completion.     

Classic shunting operations as part of two-stage repair for tetralogy of Fallot.

One hundred forty-nine consecutive patients with tetralogy of Fallot, with or without pulmonary atresia, underwent Blalock-Taussig or Waterston operation for initial palliation. Of these patients, 45 were less than 6 months old, and 63 were less than 1 year old. The type of shunt, and the presence or absence of pulmonary atresia did not have a significant effect (p greater than 0.2) on hospital mortality. Parametric analysis showed a significant effect of age (p = 0.03), the risk of hospital death being 6% at 1 month of age, 4% at 3 months, 3% at 6 months, and 2.5% at 12 months. No late deaths occurred before the age of 3 years. Six patients (4.2% of the hospital survivors) required another operation before they were 3 years old. Severe arm ischemia occurred after a Blalock-Taussig shunt in 1 infant with Down's syndrome.     

Aortic origin of the right pulmonary artery: a cause of heart failure in infancy at high altitude

The development of technique for surgical correction of aortic origin of the right pulmonary artery is described. In the first patient, aged 7 years, the operation was performed via bilateral thoracotomy, with standby for extracorporeal circulation, and the right pulmonary artery was anastomosed directly to the left, using side clamps on both aorta and left pulmonary artery. The currently preferred procedure is to operate as early as possible in infancy, using perfusion at 30 degrees C with ventricular fibrillation and without cross-clamping of the aorta. Wide mobilization of the pulmonary artery probably prevents stenosis at the end-to-side anastomosis.     

The Blalock-Taussig shunt. Low risk, effective palliation, and pulmonary artery growth

The Blalock-Taussig shunt has been used at our institution in 64 infants with cyanotic congenital heart disease who required palliation. Thirty-one of these children were less than 2 months of age at the time of operation. There were no early shunt closures. There were two hospital deaths (3%). There was only one hospital death in the 31 patients less than 60 days old. According to a life-table analysis, 87% +/- 9% (+/- 95% confidence limits) of the shunts were functioning at 1 year and 78% +/- 12% at 2 years. Results are similar in the subgroup of children less than 60 days of age at the time of operation or in the subgroup of children weighing less than 3,999 gm at operation. In infants with small pulmonary arteries, pulmonary arterial growth was excellent (ipsilateral pulmonary artery/descending aorta ratio 0.70 leads to 0.95 in 550 days, p less than 0.001; contralateral ratio 0.73 leads to 0.99 in 550 days, p less than 0.001). The Blalock-Taussig shunt can be performed with low risk, provides excellent palliation, and is associated with excellent pulmonary artery growth.     

Balloon angioplasty for pulmonary artery stenosis after lung transplantation

We report here a successful case of balloon angioplasty for a stenosis of the pulmonary artery after lung transplantation. A 49-year-old patient with end stage diffuse bronchiectasis with sinusitis underwent bilateral living donor lobar lung transplantation. After treatment of postoperative right pneumothorax, a perfusion lung scan revealed deficient perfusion in the left lung. Pulmonary angiography showed a severe stenosis in the left pulmonary artery just distal to the anastomosis. Percutaneous balloon angioplasty improved both pulmonary perfusion and respiratory function.     

Reconstruction of stenotic or nonconfluent pulmonary arteries simultaneously with a Blalock-Taussig shunt

Stenosis or discontinuity of the pulmonary arteries associated with congenital cardiac defects was repaired in 12 patients, in conjunction with the Blalock-Taussig shunt. This approach was based on the following concepts: (1) The shunted blood is more uniformly distributed to both lungs, which avoids predominance of flow to the ipsilateral lung and long-term pulmonary vascular damage; (2) because adequate blood flow is maintained, the contralateral lung growth will be near normal; (3) the possibility of future surgical correction is enhanced. The ages of the patients ranged from 2 to 24 months. Five had a primary diagnosis of tetralogy of Fallot, three had double outlet of the right ventricle, three had single ventricle, and one had a truncus type anomaly. All operations were performed without cardiopulmonary bypass. Dilation of the stenotic segment was performed in two patients, enlargement of the stenotic segment in three, and resection of the segment and end-to-end anastomosis in four. Nonconfluent pulmonary arteries were corrected in three patients. In one, the stenotic segment was resected and an anastomosis was made between the left pulmonary artery and pulmonary trunk. In another patient, a segment of the right subclavian artery was interposed between the pulmonary trunk and intrahilar left pulmonary artery. In the third patient, the right pulmonary artery was disconnected from the aorta and a tube was interposed between the right and left pulmonary arteries. There were no intraoperative or late deaths, and postoperative angiographic evaluations were satisfactory. We believe that in infants needing a Blalock-Taussig shunt the pulmonary artery anomalies, if present, should be corrected simultaneously.     

Pediatric heart transplantation after operations involving the pulmonary arteries

A prohibitive perioperative mortality has been previously ascribed to pediatric heart transplantation after palliative operations for congenital heart disease involving the pulmonary arteries. Of 46 children who have undergone heart transplantation at our institution between June 1984 and February 1990, 7 (15%; mean age 8 +/- 3 years; range 1 to 18 years) have previously undergone such operations: right ventricle to pulmonary artery conduit/homograft for levo-transposition of the great arteries (2), Waterston shunt for tricuspid and pulmonary atresia (1), pulmonary artery banding for single ventricle (1), Fontan procedure for single ventricle (1), first-stage Norwood procedure for hypoplastic left heart syndrome (1), and classic right Blalock-Taussig shunt for atrioventricular canal with pulmonic stenosis (1). Three categories of pulmonary artery anatomy that require different approaches to reconstruction at the time of transplantation are recognized: abnormalities of position, pulmonary outflow obstruction, and previous systemic- or atrial-pulmonary connections. At operation, individualized pulmonary arterial reconstruction was employed, including use of previously created right ventricular-pulmonary artery conduits/homografts and angioplasty (with and without pericardial patches). Transplantation was successful in all patients. Posttransplant right ventricular-pulmonary artery pressure gradients and pulmonary vascular resistance indices were acceptable, with a tendency to decrease with time. Two patients had critical right ventricular failure postoperatively; one of them required support with extracorporeal membrane oxygenation. There was no perioperative mortality, with three deaths occurring from 5 to 39 months after transplantation. All surviving patients are in New York Heart Association functional class I. Techniques borrowed from the repair of congenital cardiac lesions can be applied to subgroups of children undergoing heart transplantation. Additional length of donor aorta and pulmonary artery should be harvested for possible use in designing pulmonary artery connections. Previous palliative operations involving the pulmonary arteries with associated complex pulmonary artery anatomy are not of themselves an insurmountable obstacle to successful heart transplantation.