Evaluation of the complications of different types of right ventricular bypass by contrast echocardiography]

We evaluated 54 patients with different right heart by-pass by means of contrast echocardiography with rapid venous injection of shaken saline (3 cc, < 20 k; 6cc, > 20 k), in order to detect venous collateral circulation in partial by-pass, pulmonary arteriovenous fistulae in partial and total by-pass, and right-to-left shunt in total by-pass. Forty three patients had partial by-pass: 29 had a bidirectional cavopulmonary anastomosis with additional pulmonary flow (systemic-pulmonary anastomosis and/or restrictive anterograde ventricular flow); 10 had a partial ventricular correction (bidirectional cavopulmonary anastomosis and non restrictive anterograde ventricular flow; two had classical Glenn procedures; two had Kawashima operations (bidirectional cavopulmonary anastomosis and non restrictive anterograde ventricular flow; two had classical Glenn procedures; two had kawashima operations (bidirectional cavopulmonary anastomosis with inferior vena cava interruption), and 11 with total by-pass (10 atriopulmonary anastomosis and 1 with total cavopulmonary anastomosis). The age ranged from 2.5 to 33 years (x = 12.2 years), and the mean postoperative period was 4.3 years. Venous collateral circulation: 32/43 patients (74%) with partial by-pass, specially in those without partial biventricular correction: 29/33 patients (88%) compared to those with partial biventricular correction: 3/10 (30%) p < 0.01. Pulmonary arteriovenous fistulae: 6/43 patients (14%) with partial by-pass; 6/33 (18%) with partial biventricular correction, 0/10 patients with partial biventricular correction, and 0/11 with total by-pass. Right-to-left shunt: 2/11 patients (18%) with total by-pass, all of them with atriopulmonary anastomosis. Contrast echocardiography is an excellent noninvasive method for the initial evaluation of specific dysfunctions of different right heart by-pass. We emphasize the higher frequency of collateral venous circulation in cavopulmonary anastomosis, that would explain the dysfunction with progressive hypoxia in the evolution of these patients. Pulmonary arteriovenous fistulae were detected only in partial by-pass, without partial biventricular correction (p < 0.01). The minor frequency of these fistulae in bidirectional cavopulmonary anastomosis would be due to additional pulmonary flow.     

双向腔静脉肺动脉吻合术辅助治疗右心发育不良双心室解剖矫治术的实验研究

目的：在双向腔静脉肺动脉吻合术辅助下，完成双心室解剖矫治术的右心室容积最低限度值，观察血流动力学特点，为右心室发育不良的先天性心脏病双心室矫治术，提供理论基础及实验数据。方法：游离右上腔静脉，奇静脉结扎、切断；近右心房部位横行切断右上腔静脉，其远心端与右肺动脉端侧吻合，近心端缝闭，建立犬的双向腔静脉肺动脉吻合术的模型（ｎ＝１７）；采用介入性治疗二尖瓣狭窄的球囊导管（容积３０ｍｌ）作为材料，将球囊放置实验犬的右心室的心尖部，通过球囊体积的改变，形成右心室容积大小改变，建立右心室容积发育不良动物实验模型。结果：双向腔静脉肺动脉吻合术建立之后，右心室容积为正常的２５％以下时，主要血流动力学指标出现明显改变，如：血压、心率、心输出量等。结论：如果右心室容积是正常的２５％以上，则可以在双向腔静脉肺动脉吻合术辅助下完成双心室解剖矫治术。     

Reopening of persistent left superior caval vein after bidirectional cavopulmonary connections

Persistent left superior vena cava (SVC) is a not uncommon finding in patients with congenital heart disease. This anatomical variant must be recognised before doing a Glenn anastomosis, bidirectional cavopulmonary connection or a Fontan-type procedure. Following these procedures, reopening of a left SVC leading to clinical cyanosis can occur. Five cases are described in whom persisting left SVCs were excluded before performing a bidirectional cavopulmonary connection or Fontan procedure but (re-)opened after surgery, leading to cyanosis either by reducing effective pulmonary blood flow (bidirectional cavopulmonary connection) or by an obligatory right to left shunt (Fontan). These observations suggest that, embryologically, the lumen of the left SVC obliterates rather than disappears. Balloon occlusion angiography of the innominate vein before cavopulmonary connections or Fontan procedures might improve detection of these collateral vessels.

Keywords: persistent left superior vena cava; cavopulmonary connection; Fontan procedure; congenital heart disease     

Bidirectional cavopulmonary anastomosis in congenital heart disease. Functional and clinical outcome.

The bidirectional cavopulmonary anastomosis is a surgical procedure suitable for patients with cyanotic congenital heart disease and univentricular physiology. This operation is able to increase the effective pulmonary blood flow without any additional load on the cardiac work and without any further distortion on the pulmonary artery branches. The cavopulmonary anastomosis can represent the first stage for patients destined for Fontan repair or a definitive palliative operation in high risk Fontan candidates. In order to test the hypothesis of a definitive palliation by cavopulmonary anastomosis in this kind of patients, we evaluated the hemodynamic data before and after this surgical approach and compared these data with their clinical and functional outcome. We evaluated 74 patients submitted to bidirectional cavopulmonary anastomosis by either hemodynamic or functional evaluation. End-diastolic and end-systolic ventricular volumes were significantly reduced by bidirectional cavopulmonary anastomosis (p less than 0.0005). Despite these data and a normal ambulatory ECG, spirometry and echocardiographic analysis, the stress test showed discouraging results. In fact, mean work time and peak heart rate were significantly different from normal values showing an impaired functional capacity of these children. In conclusion we think that bidirectional cavopulmonary anastomosis can not be considered an adequate definitive palliation but it represents a very good stage to preserve the pulmonary arteries and to prepare the systemic ventricle towards the Fontan repair.     

Palliation of complex cardiac anomalies with subaortic obstruction: new operative approach

The modified Fontan operation for complex cardiac anomalies associated with subaortic obstruction entails a high surgical risk. It is likely that ventricular hypertrophy secondary to chronic pressure overload plays a significant role. This problem was approached with a new type of palliative operation comprising both a proximal pulmonary artery to ascending aorta anastomosis and a bidirectional cavopulmonary anastomosis. This operation was performed in six children ranging in age from 26 to 63 months. There was one intraoperative death due to hemorrhage. In one patient, a pulmonary to aorta conduit caused compression of the right coronary artery; the problem was solved by lengthening the conduit with a second period of cardiopulmonary bypass. The five survivors experienced an uneventful postoperative course. Repeat cardiac catheterization in these five patients showed low pressure in the cavopulmonary system (mean 10 mm Hg), absence of a gradient at rest between the systemic ventricle and aorta and fair arterial oxygenation (mean 82%). A technetium-99m perfusion lung scan visualized a slight prevalence of pulmonary blood flow ipsilateral to the shunt in three cases, whereas in one case preferential flow to the right lung was associated with a narrowing at the site of the cavopulmonary anastomosis. Mild hypoperfusion of the anterior pulmonary segments was observed in two cases. Both pressure and volume overload are abolished with this procedure and a satisfactory oxygenation is provided. Low venous pressure in the coronary, hepatic and renal areas as well as the short bypass time may explain the smoothness of the postoperative course in our patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Systemic venous collateral development after the bidirectional cavopulmonary anastomosis: Prevalence and predictors

Objectives. To determine the prevalence of systemic venous collaterals after the bidirectional cavopulmonary anastomosis and the factors associated with their development.Background. Systemic venous collaterals have been found after cavopulmonary anastomosis.Methods. Cardiac catheterization was performed in 103 patients before and after a bidirectional cavopulmonary anastomosis.Results. After surgery, 51 venous collaterals were identified in 32 patients (31%). Collateral development was associated with an abnormal superior vena caval connection (56% incidence vs. 26% with a single right superior vena cava, p = 0.01) and postoperative factors including pulmonary artery distortion (53% incidence vs. 22% without distortion, p = 0.002); increased superior vena caval mean pressure (14 ± 5 mm Hg versus 11 ± 4 mm Hg with no collaterals, p = 0.0002); increased pulmonary artery mean pressure (13 ± 4 mm Hg vs. 11 ± 4 mm Hg with no collaterals, p = 0.02); lower right atrial mean pressure (5 ± 2 mm Hg vs. 6 ± 3 mm Hg with no collaterals, p = 0.04); and increased mean gradient between superior vena cava and right atrium (8 ± 3 mm Hg vs. 5 ± 4 mm Hg with no collaterals, p = 0.0002). Using multiple logistic regression, only this last factor was independently associated with collateral development with an odds ratio per 1 mm Hg of 1.33 (95% CI 1.12–1.58, p = 0.001) for their presence.Conclusions. Systemic venous collaterals occur frequently after a bidirectional cavopulmonary anastomosis and are found postoperatively when a significant pressure gradient occurs between cava and right atrium.     

A better approach for left ventricular training in transposition of the great arteries and intact interventricular septum: Bidirectional cavopulmonary anastomosis and pulmonary artery banding

Objective: Management of the patients with transposition of the great arteries and intact ventricular septum may be challenging beyond the newborn period. Herein, we would like to present our alternative strategy for training the left ventricle in these patients.
Methods: Six patients with transposition of the great arteries and intact ventricular septum were evaluated in our clinic. Two of them were palliated with Glenn procedure and pulmonary banding as a definitive treatment strategy at other centers. Four patients were operated on and a bidirectional cavopulmonary anastomosis in combination with pulmonary artery banding was performed (stage‐1: palliation and ventricular training) in our center. In four out of these six patients, arterial switch operation was performed with takedown and direct re‐anastomosis of the superior vena cava to right atrium after an interstage period of 21‐30 months (stage‐2: anatomical repair).
Results: Any mortality was not encountered. The left ventricular mass indices increased from 18‐32 to 44‐74 g/m2 in patients undergoing the anatomical repair. All of the patients were uneventfully discharged following the second stage. The mean follow‐up period was 20 months (9‐32 months) following stage 2. All of the patients are doing well with trivial neoaortic regurgitation and normal biventricular function.
Conclusions: Bidirectional cavopulmonary anastomosis with pulmonary artery banding may be a promising left ventricle training approach in ventriculoarterial discordance when compared to the traditional pulmonary artery banding with concomitant systemic‐to‐pulmonary artery shunt procedures which still carry a significant interstage morbidity and mortality.     

Surgical considerations of univentricular heart with total anomalous pulmonary venous connection

Out of the 600 patients undergoing univentricular repair during the last 11 years, 20 children had associated total anomalous pulmonary venous connection. The objective was to outline the clues to establish the diagnosis of this rare disease combination and the various surgical options available to manage the same. Bidirectional Glenn, bilateral bidirectional Glenn, total cavopulmonary connection and atriopulmonary connection were performed in combination with rechannelling of various types of total anomalous pulmonary venous connection in 20 children aged 6 months to 36 months (mean +/- SD 17.65 +/- 9.02 months). Diagnosis could be established pre-operatively in only 13 (65%) patients. Out of 6 early deaths (30%), 4 were directly attributable to missed diagnosis. No late deaths occurred over a follow-up period ranging from 1 month to 132 months. None of the surviving children required reoperation and all are in NYHA functional class I. Doppler echocardiography of the surviving children revealed unrestricted atrio/cavopulmonary anastomosis and pulmonary vein to atrium connection in all survivors. Our own experience, coupled with a review of the literature, indicates that a missed diagnosis increases the hospital mortality. Cross sectional 2D echocardiography is a superior method of detection of associated total anomalous pulmonary venous connection compared to angiocardiography. Exclusion of the diagnosis of anomalous pulmonary venous connection is imperative in all univentricular hearts pre-operatively and on operation table. Failure to recognise this disease combination results in formation of a closed systemic circuit after bidirectional Glenn or a modified Fontan of connection and is lethal as happened in our early experience. It is suggested that one-stage Fontan operation should be performed only if other criteria for Fontan procedure are satisfied.     

Surgical outcome of staged univentricular-type repairs for patients with univentricular physiology and pulmonary hypertension

BACKGROUND: There is no consensus about the most appropriate limits of pulmonary artery pressure and vascular resistance in case of patients undergoing univentricular or one and one-half ventricular repair. This study was conducted to analyze the mortality and morbidity of a heterogenous group of patients with a functionally univentricular heart and pulmonary artery hypertension, undergoing pulmonary artery banding followed by univentricular-type repairs. METHODS AND RESULTS: Out of 254 patients undergoing pulmonary artery banding for a functionally univentricular heart with increased pulmonary blood flow, 148 patients underwent definitive second stage surgery. Post-band hemodynamic evaluation revealed persistently high pulmonary artery pressure (> 18 mmHg), and pulmonary vascular resistance (>2.0 Woods units/m2) in 78.3% patients. Sixteen patients with moderate right ventricular hypoplasia were given a one and one-half ventricle repair (Group I), 82 patients a bidirectional Glenn connection (Group II), and 50 patients a fenestrated total cavopulmonary connection (Group III). The overall mortality following second stage surgery for the high pulmonary artery pressure group (n=116) was 30.17%, while none of the low pulmonary artery pressure group died (p=0.0009). Pulmonary hypertensive crises and/or systemic desaturation were the main causes of death at second stage repair. All mortality occurred in patients with mean pulmonary artery pressure > 18 mmHg and pulmonary vascular resistance > 3.5 Woods units/m2. Survivors from this group had persistent morbidity in the form of superior vena caval syndrome and suboptimal oxygen saturation (70-75%). CONCLUSIONS: It is advisable not to proceed with definitive second stage repair if post-pulmonary artery banding mean pulmonary artery pressure is over 25 mmHg and pulmonary vascular resistance exceeds 4.0 Woods units/m2. These patients may possibly be deemed to have undergone definitive palliation during their pulmonary artery banding.     

Persistence of bilateral arterial ducts in pulmonary atresia despite confluent branch pulmonary arteries: opportunity for two percutaneous therapeutic alternatives.

We present a case of a newborn infant with double inlet left ventricle, pulmonary atresia, confluent pulmonary arteries, and bilateral arterial ducts (AD), to discuss the therapeutic alternatives offered by interventional catheterization techniques in this anatomic arrangement. The infant initially underwent stenting of the right AD to stabilize pulmonary blood flow off of prostaglandin infusion. Three weeks later, she developed left pulmonary artery isolation upon closure of the left arterial duct. An additional stent was placed in the pulmonary artery confluence, restoring blood flow to the left lung and significantly improving her oxygen saturations. At 6 months of age she underwent her first surgical procedure, a successful bidirectional cavopulmonary anastomosis with removal of the left pulmonary artery stent and patch enlargement of the pulmonary artery confluence. She continues to do well in clinical follow-up at 16 months of age.     

Does hypoplasia of one pulmonary artery preclude a definitive repair in pulmonary atresia,intact ventricular septum,and hypoplastic right ventricle?

Summary Twins with pulmonary atresia, intact ventricular septum, and hypoplastic right ventricle associated with underdeveloped and discontinuous left pulmonary artery are described. Operations to connect the left pulmonary artery to the main pulmonary trunk, with subsequent biventricular repair assisted by bidirectional cavopulmonary anastomosis and atrial fenestration were performed. Follow-up catheterization proved spontaneous closure of the fenestration in one patient. Both patients have been in a satisfactory condition for 3 years since operation.     

The bidirectional Glenn operation in 100 cases with complex congenital heat diseases: factors influencing surgical results]

OBJECTIVE: The bidirectional Glenn shunt is a well established surgical technique in children with complex congenital heart disease. The present study is a retrospective analysis of patients undergoing this operation in order to assess the influence of different variables in the outcome. PATIENTS AND METHOD: From December 1990 to June 2000, 100 patients received a bidirectional Glenn shunt.Two groups were defined, based on the outcome. Group A (n = 15, unsuccessfully result) including death and need to reoperate, and Group B (n = 85, patients with good outcome). RESULTS: The mortality was 8%. Eight patients were reoperated at follow-up. The survivors were followed for a mean of 3.5 years. Mean pulmonary artery pressure 7 mmHg was a factor associated with poor clinical progress. Other variables (age less than 1 year, excessive pulmonary blood flow, double Glenn operation, significant anatomic anomalies, and arrythmias), were also associated with outcome. Significant variations were observed in the time of by-pass or the need for aortic clamp in cases with simultaneous operative repair of pulmonary branch stenosis. Actuarial survival rate, most more than 1 year was 92%, and freedom from reoperation at 3 years was 90%. CONCLUSIONS: The bidirectional Glenn shunt is an excellent palliation in patients with functionally single ventricle. Mean pulmonary artery pressure was the most important variable related with the outcome. We are encouraged to continue with tendency to perform bidirectional Glenn shunt preferably early, avoiding, whenever possible, previous palliative surgery.     

Bidirectional superior cavopulmonary anastomosis: how young is too young?

OBJECTIVE--To define the lowest age at which the bidirectional superior cavopulmonary anastomosis can safely be used in infants with complex congenital heart defects. DESIGN--A retrospective analysis of clinical, echocardiographic, haemodynamic, and angiographic data in four consecutive patients undergoing bidirectional superior cavopulmonary anastomosis below the age of 2 months. PATIENTS--Between November 1990 and September 1993, four infants less than 8 weeks of age (3, 4, 6, and 7 weeks) underwent bidirectional superior cavopulmonary anastomosis as a primary palliation for complex heart disease. The indication for early surgical intervention was progression of cyanosis (n = 3) and high pulmonary blood flow causing heart failure (n = 1). In two infants with tricuspid atresia, surgery was performed through a right thoracotomy without the use of cardiopulmonary bypass. In one infant with double inlet left ventricle and discordant ventriculoarterial connection, cavopulmonary anastomosis was combined with an arterial switch procedure. The final infant had double inlet left ventricle with pulmonary atresia; the central pulmonary arteries were virtually discontinuous and each branch was supplied by a separate arterial duct. The central pulmonary arteries were reconstructed using the subaortic innominate vein. Temporary prostacyclin infusion was used in three patients in the immediate postoperative period. RESULTS--Early postoperative extubation (5, 7, and 48 h) was successful in three patients. The youngest child required ligation of the ductus arteriosus four days later because of severe upper body oedema. The postoperative course was complicated by prolonged effusions in two patients. All were alive and well 14-48 months postoperatively, with satisfactory systemic saturations (80-87%) and haemodynamic indices. CONCLUSIONS--This limited experience challenges the widely held belief that the bidirectional superior cavopulmonary anastomosis cannot be used as a primary palliation for complex heart disease in early infancy. A wider experience is required to determine the safety and indications for this approach.     

Treatment of elevated pulmonary artery pressure in a child after Glenn procedure: transcatheter closure of pulmonary artery banding with subsequent sildenafil therapy

An additional source of pulmonary blood flow in a patient with bidirectional Glenn procedure (BGD) may cause elevation of mean pulmonary artery pressure (MPAP), precluding safe completion of the Fontan operation. We present a case of single ventricle physiology after pulmonary artery banding (PAB) and Glenn procedure. At the age of six years, cardiac catheterisation revealed in the patient elevated MPAP (22 mm Hg). The PAB was closed through the right internal jugular vein with an Amplatzer Atrial Septal Occluder. After the procedure, MPAP remained at a similar level. Sildenafil oral therapy was applied for six months. Subsequent heart catheterisation confirmed complete closure of PAB and decrease of MPAP to 10 mm Hg. The abovementioned complex treatment of elevated MPAP pressure in a child after Glenn therapy allowed safe completion of the Fontan operation.     

Repeat balloon occlusion of a pulmonary arteriovenous fistula following cavopulmonary anastomosis in tetralogy of fallot

A 30-year-old woman with Tetralogy of Fallot and cavopulmonary anastomosis (Glenn shunt) presented with a large pulmonary arteriovenous fistula in the right lower lobe. This report describes the successful management following two successive therapeutic balloon embolizations.     

Pulmonary venous wedge pressure provides an accurate assessment of pulmonary artery pressure in children with a bidirectional Glenn shunt

PURPOSE: In circulations with pulsatile pulmonary artery flow the pulmonary venous wedge pressure (PVWp) has been validated as a good estimate of pulmonary artery pressure (PAp), when PAp is low. The purpose of this study was to validate PVWp estimates of PAp in the less-pulsatile pulmonary circulation of children after bidirectional Glenn shunts. METHODS: A retrospective study was performed of 22 simultaneous measurements of PVWp and PAp made during 20 catheterizations in 19 children who had undergone bidirectional Glenn procedures. The PAp was measured directly from the branch PA ipsilateral to the side of the PVWp, or in the SVC. Pulmonary resistance (Rp) was calculated with both PAp and PVWp, to assess the impact of PAp estimates on Rp determinations. RESULTS: Patients ranged in age from 5 months to 10.7 years. There were a variety of univentricular cardiac malformations in the study group. Two children had antegrade pulmonary blood flow in addition to a bidirectional Glenn shunt. The mean PAp ranged from 4 to 14 mmHg, while mean PVWp ranged from 3 to 15 mmHg. Mean PVWp never differed from mean PAp by more than 3 mmHg. There was a significant linear relation between mean PAp and PVWp: PAp = 0.86 (PVWp) + 2.0 (R2 = 0.89; P < 0.0001). PVWp provided a good approximation of PAp regardless of the presence (n = 2) or absence (n = 19) of antegrade pulmonary flow. There was a good linear correlation between the Rp calculated by both methods (RpPAp = 0.9 (RpVWp) + 0.5; R2 = 0.74; P < 0.0001). CONCLUSION: The mean PVWp provides a close approximation of mean PAp in children with a bidirectional Glenn shunt and provides valuable hemodynamic information in cases where direct PAp measurements are unavailable.     

Risk factors in the Glenn bidirectional shunt as an intermediate procedure before Fontan correction

OBJECTIVE: The bidirectional Glenn shunt is the most common palliation before the Fontan repair, especially in high-risk patients. We studied the influence of certain risk factors in bidirectional Glenn results, with and without an additional source of pulmonary blood flow. METHODS: Between 1993 and 1998 twenty patients (6-53 months of age) underwent a bidirectional Glenn shunt as the intermediate repair for the Fontan procedure. Diagnoses were: 7 cases of double inlet single ventricle, 4 of tricuspid atresia, 3 of unbalanced AV septal defect, 4 of mitral atresia, 1 hypoplastic left heart syndrome and 1 TGA with hypoplasia of the right ventricle. 17 patients had undergone previous operations. Mean preoperative arterial oxygen saturation was 78.5%. In 6 patients an auxiliary source of pulmonary blood flow was added. RESULTS: Hospital mortality was 15%. In 4 patients the bidirectional Glenn failed. By univariate analysis low weight, preoperative functional status and high pulmonary pressure were factors associated with early death. In bidirectional Glenn failure only the duration of ventilatory support was significant. By multivariate analysis, preoperative functional status and pulmonary pressure were significant. Mean postoperative arterial oxygen saturation at a mean follow-up of 10 months was 84%. CONCLUSIONS: Bidirectional Glenn shunt is an effective and low-risk palliation for patients with univentricular hearts. Only low weight and high pulmonary pressure were significant in hospital mortality, and we advise the association of an additional source of pulmonary blood flow in these patients at the start. Early extubation provides correct performance of the shunt.     

Catheter conversion of classic glenn to bidirectional glenn with closure of left central shunt years after surgical attempts

Bidirectional Glenn shunt is usually performed in patients with single ventricle in preparation for a total cavo‐pulmonary connection. We present a patient born with complex congenital heart disease consisting of single ventricle, pulmonary atresia, non confluent pulmonary arteries, and anomalous pulmonary venous return in whom surgical bidirectional Glenn was attempted. After multiple surgical attempts she was converted to a Classic Glenn and a central ascending aorta to left pulmonary artery shunt. Several years later by the aid of radiofrequency wire the occluded pulmonary artery segment was canalized establishing continuity between the two pulmonary artery branches with stenting of the intervening segment. The central shunt to the left pulmonary artery was subsequently embolized. Thus this patient was converted in the catheterization laboratory from the physiology of a classic Glenn to the more preferred bidirectional Glenn physiology. © 2011 Wiley Periodicals, Inc.