A case for anatomic correction in atrioventricular discordance? Effects of surgery on tricuspid valve function

OBJECTIVE: To assess tricuspid valve function in atrioventricular discordance after palliative procedures (pulmonary artery banding and Blalock-Taussig shunt) and corrective procedures (anatomic and physiologic repair). METHODS: Tricuspid valve dysfunction was assessed by transthoracic echocardiography and graded as no regurgitation (0), mild (1), moderate (2), and severe (3) before and after palliative and corrective procedures performed in 97 patients with atrioventricular discordance between 1988 and 1999. Thirty-two percent had an isolated ventricular septal defect, 43% had a ventricular septal defect and pulmonary stenosis, and 16% had pulmonary stenosis. Twenty-six patients underwent pulmonary artery banding and 28 had a Blalock-Taussig shunt. Seventy patients underwent physiologic and 19 underwent anatomic repair. Six patients underwent one-ventricle repair. RESULTS: After pulmonary artery banding, the tricuspid regurgitation score decreased from 1.7 +/- 0.8 to 0.9 +/- 0.6 (P <.001). In patients who underwent a Blalock-Taussig shunt, the tricuspid regurgitation score increased from 0.7 +/- 0.5 preoperatively to 1.4 +/- 0.6 postoperatively (P <.001). After physiologic repair, there was no significant change in the tricuspid regurgitation score; however, 7 patients required additional repair or replacement. The regurgitation score was significantly reduced from 1.5 +/- 0.8 to 0.4 +/- 0.5 (P <.001) after anatomic repair. The operative mortality in patients who underwent physiologic repair was 7% as compared with 0% in the anatomic repair group (P =.59). The median follow-up was 3.2 years. CONCLUSIONS: Right ventricular volume loading (shunt) worsens tricuspid regurgitation, whereas volume reduction (banding) or left-to-right septal shift (anatomic repair) has beneficial effects. We have not observed a significant change in the tricuspid regurgitation score after physiologic repair. Anatomic repair can be performed in selected patients with atrioventricular discordance and provides superior functional results.     

Reverse Blalock-Taussig shunt facilitates the growth of the ascending aorta after hybrid palliation

A 13-day-old baby girl with tricuspid atresia (IIc), who was prematurely born at 32 weeks and 5 days of gestation and weighed 2.2 kg, underwent bilateral pulmonary artery banding, ductal stenting, and reverse Blalock-Taussig shunt. Cardiac computerized tomography at 4 months postoperatively showed that the ascending aorta outgrew the somatic growth, presumably thanks to the forward flow through the reverse Blalock-Taussig shunt. At 6 months postoperatively, the patient underwent a successful second-stage operation.     

Heart transplantation using bicaval anastomosis to concomitantly relieve superior vena caval obstruction in a pediatric patient with heart failure

We describe a case of complex congenital heart disease treated using balloon septostomy, pulmonary artery banding. Blalock-Taussig shunt, and cardiac resynchronization therapy; however, heart failure developed. A bicaval anastomosis was used to relieve superior vena cava (SVC) obstruction despite possible anastomotic stenosis. The postoperative course was uneventful and the patient recovered rapidly. Thus, we recommend bicaval anastomosis using a longer donor SVC concomitantly performed during heart transplantation to relieve both heart failure and SVC obstruction in pediatric patients.     

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.     

Acute pulmonary edema after Blalock-Taussig anastomosis.

Acute pulmonary edema developed in 2 patients after a Blalock-Taussig shunt procedure. Both patients had a univentricular heart complex with pulmonary stenosis. One patient underwent a modified Blalock-Taussig shunt using a polytetrafluoroethylene tube and the other underwent a classic Blalock-Taussig anastomosis. Acute pulmonary edema after the Blalock-Taussig shunt is rare, but once it has occurred, immediate treatment is obligatory.     

Surgical strategy for pulmonary coarctation in the univentricular heart.

OBJECTIVE: The placement of a modified Blalock-Taussig shunt in patients suffering from pulmonary coarctation can result in the aggravation of uneven pulmonary blood flow. This may subsequently obviate the possibility of future performance of the Fontan procedure. The objective of this study was to evaluate mid-term results in patients with pulmonary coarctation who had undergone the placement of a modified Blalock-Taussig shunt, coupled with a pulmonary artery angioplasty. METHODS: We retrospectively reviewed the records of 13 patients who had undergone the placement of a modified Blalock-Taussig shunt, coupled with concomitant pulmonary angioplasty, between September 1998 and August 2002. All patients received follow-up angiographic evaluations. RESULTS: On the ipsilateral side of the modified Blalock-Taussig shunt, we observed a significant increase in the pulmonary artery index during a mean follow-up period of 11+/-5 months (preoperative 82+/-37 mm2/m2, follow-up 129+/-57, p=0.03). On the contralateral side, we also observed a significant increase in the pulmonary artery index (preoperative 90+/-56 mm2/m2, follow-up 137+/-56, p=0.047). There was one late death. During the follow-up period (mean 23+/-18 months), 10 patients received either a bidirectional or total cavopulmonary shunt and five of these patients underwent extracardiac Fontan operations. CONCLUSIONS: Our study demonstrated that the placement of a modified Blalock-Taussig shunt, with concomitant pulmonary artery angioplasty, constitutes a good initial surgical strategy in cases of univentricular heart with pulmonary coarctation.     

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.     

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.     

A Five-Year Clinical Experience with 112 Blalock-Taussig Shunts

In spite of recent advances in neonatal open repair for complex cyanotic heart disease, some patients require palliation with a systemic-to-pulmonary artery shunt. We report a 5-year experience (1985–1990) with 112 Blalock-Taussig shunts. Forty-six of the 92 patients had some variant of tetralogy of Fallot, with a wide spectrum of diagnoses in the remainder. The median age at surgery was 3 months. A classic Blalock-Taussig shunt was done in 26% (group I), and a 4- or 5-mm PTFE graft was utilized in the remainder (group II). The technical aspects of each of the procedures are reviewed. There were three early deaths in the entire group, none of them related to Blalock-Taussig shunt function. There was no incidence of early shunt insufficiency, bleeding, infection, limb ischemia, or pulmonary artery distortion. There was a 21% incidence of clinical congestive heart failure, seen somewhat more commonly in group I. The overall need for reshunting/open repair was similar in both groups, but there was a statistically longer interval between the initial Blalock-Taussig shunt and the second procedure in group I (21.6 vs 12.4 months). The Blalock-Taussig shunt remains a safe, reliable, and effective means of increasing pulmonary flow. (J Card Surg 1993; 8:9–17)     

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.     

The Blalock-Taussig shunt for simple complete transposition of the great arteries followed by later anatomic correction. Report of 2 cases with conflicting postoperative courses

The Blalock-Taussig (BT) shunt was performed in two infants with simple transposition of the great arteries (TGA) after poor response to septostomy not only to improve hypoxia but also in expectation of preparing the left ventricle for later anatomic correction. One patient had adequate muscle mass and pressure of the left ventricle after the shunt and underwent successful anatomic correction. The other patient developed intractable heart failure following the shunt. Anatomic correction was performed with success in this patient after pulmonary artery banding and takedown of the BT shunt. Based on these experiences, if heart failure does not develop or is controllable after BT shunt, there may be a possibility of later anatomic correction. However, if uncontrollable failure occurs, the shunt should be taken down and arterial or venous switch correction should be performed as soon as possible.     

Adjustable aorto-pulmonary shunt to prevent temporary pulmonary over-circulation.

The Blalock-Taussig shunt can produce a temporary pulmonary over-circulation and can be downsized with a metallic clip. This hemodynamic situation can be reversible leading to desaturation. We describe a very simple method to resize temporarily the shunt with a removable metallic clip.     

Adjustable tourniquet to manipulate pulmonary blood flow after Norwood operations

Background. Survival after first-stage palliative Norwood operations for single ventricle with systemic outflow obstruction is mainly dependent on a balanced ratio of pulmonary blood flow to systemic blood flow. Here we report the clinical results using a modified technique that allows a controlled systemic-to-pulmonary shunt flow to prevent pulmonary overcirculation.

Methods. From 1995 to 1998, of 26 infants undergoing first-stage palliative Norwood operations, 7 had placement of an adjustable tourniquet around a modified right Blalock-Taussig shunt.

Results. Hospital survival was 20 of 26 patients (77%). All 7 patients in whom snaring of the shunt was indicated survived. Two patients underwent repeated adjustment, in 5 patients the tourniquet could be removed during delayed sternal closure, and 2 patients were discharged with the shunt partially snared.

Conclusions. The snare-controlled systemic-to-pulmonary shunt allows improved hemodynamic stability after reconstructive surgery for hypoplastic left heart syndrome or other similar complex cardiac defects by reducing the risk of pulmonary overcirculation. It is simple and rapidly executed. The option of graded banding of the shunt depending on the hemodynamic situation increases flexibility and safety after cardiopulmonary bypass or at any time in the postoperative period.     

Surgical palliation of cardiac malformations associated with right isomerism

Between 1985 and 1993, palliative surgery was performed on 13 pediatric patients who had complex cardiovascular anomalies associated with right isomerism. The patients included two neonates, ten infants, and one child who were divided into two groups according to whether or not a total anomalous pulmonary venous connection (TAPVC) was present. Group 1 consisted of six patients with TAPVC and group 2 consisted of seven patients without TAPVC. In group 1, the surgical procedures involved TAPVC repair alone in two patients, combined TAPVC repair with a modified Blalock-Taussig shunt in two, combined TAPVC repair with pulmonary artery banding in one, and a modified Blalock-Taussig shunt alone in one. There were five hospital deaths and one late death in this group: pulmonary venous obstruction in two patients, perioperative myocardial failure in the two neonates, and congestive heart failure caused by increased pulmonary blood flow in two patients. In group 2, all the patients underwent systemic-pulmonary artery shunts, and there was one hospital death and three late deaths, the causes of which were unknown in two patients, and shunt failure and pneumonia in one patient each. These results suggest that surgical palliation for right isomerism produces poor results in young infants with obstructed TAPVC. Thus, we conclude that TAPVC repair should be performed without delay if pulmonary venous obstruction has been diagnosed clinically. Resolving pulmonary venous obstruction without cardiopulmonary bypass (CPB) may be preferable for infants, considering their difficult management. The systemic-pulmonary artery shunt should be of the low-calibrated type, especially if common atrioventricular valve regurgitation exists. If infants survive the surgery, they must be carefully followed up for a long period due to the risk of sudden death or infection.     

Classic Blalock-Taussig shunt in neonates

BACKGROUND: The choice of palliative procedure for neonates with congenital cyanotic heart defects remains controversial. Several reports have questioned whether the classic Blalock-Taussig shunt is adequate in neonates, because it shows a high rate of mortality and early shunt failure. The purpose of this study is to evaluate the early and late results of classic Blalock-Taussig shunt in neonates. METHODS: From December 1981 to December 1996, 31 neonates underwent a classic Blalock-Taussig shunt. Mean age at operation was 15.9 days (range, 2 to 28 days), and mean body weight was 3214 g (range, 2229 to 4468 g). The major diagnoses were pulmonary atresia with intact ventricular septum (6 patients) and with ventricular septal defect (4), univentricular heart (6), tricuspid atresia (5), tetralogy of Fallot (4), transposition of the great arteries (3), and double outlet right ventricle (3). RESULTS: There were no early deaths. There was one early shunt failure. The patient underwent a replacement of Blalock-Taussig shunt by vascular graft on the 1st postoperative day. Two patients with non-confluent central pulmonary artery underwent a contralateral modified Blalock-Taussig shunt on the 22nd and 42nd postoperative day, respectively. There were two late deaths before the definitive repair was performed. Twelve patients required an additional shunt operation. The mean interval between the initial and the second shunt procedure was 27.7 months (range, 6 to 67 months). Ten patients underwent definitive operation and the mean interval to that procedure was 55.5 months (range, 14 to 121 months). Shunt patency was 94.7+/-5.1% at 3 years. The freedom from cardiac event (cardiac deaths or repeat shunting procedure) was 80.5+/-7.1% at 1 year and 54.9+/-9.4% at 3 years. CONCLUSIONS: The classic Blalock-Taussig shunt has a low operative mortality and has provided excellent long-term palliation in the neonate. We conclude that a classic Blalock-Taussig shunt should be considered a reasonable choice in neonates requiring a palliative procedure for congenital cyanotic heart defects.     

When should pulmonary artery angioplasty be performed for fontan candidates with pulmonary coarctation?

We performed concomitant pulmonary artery angioplasty and the Blalock-Taussig shunt under median sternotomy and cardiopulmonary bypass at the neonatal stage in Fontan candidates with pulmonary coarctation to obtain optimum pulmonary circulation. This surgical strategy realized appropriate early growth of the pulmonary artery necessary for the Fontan operation.     

Pulmonary atresia with intact ventricular septum: is neonatal repair advisable?

The optimal management of pulmonary atresia with an intact ventricular septum in the neonate remains controversial. The introduction of balloon septostomy and prostaglandin has significantly reduced early mortality but early surgical intervention is necessary to obtain a more adequate pulmonary blood flow. Fourteen neonates with pulmonary atresia and an intact ventricular septum were admitted to the Wessex Cardiothoracic Unit, Southampton from 1979 to 1986. Thirteen patients underwent cardiac catheterization. Cardiac catheterization data and right ventricular angiograms were reviewed retrospectively. Four patients with tripartite ventricles underwent total repair. The others received various palliative operations (valvotomy + modified Blalock-Taussig shunt or modified Blalock-Taussig shunt alone). Retrospective analysis of the angiograms indicated that right ventricular morphology alone is not a satisfactory criterion for surgical management. We have been able to demonstrate that there is a good correlation between the diameter of the tricuspid valve and the diameter of the infundibulum and that successful neonatal repair is possible when the tricuspid valve diameter is above 80% of the normal value for weight and when the tricuspid valve diameter to infundibular diameter ratio (TV/Inf ratio) is 2.2 or less. In patients with a tripartite ventricle but inadequate TV diameter and TV/Inf ratio, a closed pulmonary valvotomy with a modified Blalock-Taussig shunt remains the treatment of choice.     

Complete atrioventricular canal and tetralogy of Fallot with pulmonary atresia

Our patient was diagnosed with complete atrioventricular canal and Tetralogy of Fallot with pulmonary atresia at the age of 1 month. Then he underwent right and left Blalock-Taussig shunts at the ages of 2 months and 5 years, respectively. His cyanosis had increased at 20 years of age. Cardiac catheterization showed occlusion of the left Blalock-Taussig shunt and absence of the left pulmonary artery. Lung perfusion scintigram showed late phase perfusion in the left lung. Chest computed tomographic scan demonstrated the left pulmonary artery. We describe the operative technique of total correction.     

Diminished Blalock-Taussig shunt flow detected by cerebral oximetry

Near-infrared spectroscopy is a noninvasive optical technique used to monitor brain tissue oxygenation. Measurement of cerebral oxygenation is a more sensitive monitor of oxygen delivery to the brain than other available monitors. Prolonged cerebral desaturation is correlated with poor neurological outcomes. We report a case where the cerebral oximeter alerted us to diminished blood flow in a preexisting Blalock-Taussig (subclavian artery to pulmonary artery) shunt.