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.     

Factors influencing survival in patients after bidirectional Glenn shunt

Clinical characteristics, echocardiographic values, and catheterization data of 45 patients with a functional univentricular heart who had a bidirectional Glenn shunt instituted between November 1994 and October 2006 were retrospectively reviewed. Median age at operation was 20 months (range, 9 months to 19 years). Median follow-up time after the bidirectional Glenn operation was 4 years (range, 1 day to 11 years). The early mortality rate was 4/45 (8.9%); overall mortality was 24.4%. Actuarial survival after a bidirectional Glenn shunt was 73% +/- 8% at 5 years and 55% +/- 17% at 10 years. In multivariate Cox proportional hazards analysis, heterotaxy syndrome and systemic right ventricle were independent predictors of mortality after the bidirectional Glenn shunt. Age at operation, oxygen saturation, previous surgery, a pulsatile Glenn shunt, cardiopulmonary bypass, postoperative pulmonary artery pressure, bilateral superior venae cavae, and Nakata index were not predictive of mortality. The presence of heterotaxy syndrome and systemic right ventricle in patients with a functional univentricular heart should lead to aggressive investigation and management strategies.     

超声评价肺血减少型复杂先天性心脏病双向Glenn术后肺血管发育的临床价值

目的:探讨超声心动图评价肺血减少型复杂先天性心脏病(先心病)双向Glenn分流术后肺血管发育的临床应用价值。方法:应用二维经胸超声心动图测量101例复杂发绀型先心病患儿双向Glenn分流术前后左、右肺动脉内径,同时测量术前、术后经皮血氧饱和度,评价其术后肺血管发育。根据有无肺动脉前向血流将患儿分为肺动脉闭锁组(30例)和肺动脉狭窄组(71例);另分为婴幼儿组(年龄≤3岁,51例)和儿童组(年龄>3岁,50例),比较各组内及组间手术前后肺动脉分支内径及血氧饱和度变化。结果 :术后应用超声心动图随访12～36个月,左、右肺动脉内径及血氧饱和度较术前有不同程度改善。肺动脉狭窄组较肺动脉闭锁组术后肺动脉生长发育及血氧饱和度的改善更明显;婴幼儿组肺动脉发育及血氧饱和度改善情况优于儿童组(P<0.01)。应用超声定量的肺动脉分支发育与临床血氧相关性回归分析结果满意(P<0.001)。结论:肺血减少型复杂先心病患儿施行双向Glenn分流术后,可在不增加右心室前负荷情况下增加肺血流,促进患者肺动脉血管发育,提高血氧饱和度。超声心动图对术后定量随访评估肺血管发育,评估预后有重要的临床应用价值。     

Catheter closure of accessory pulmonary blood flow after bidirectional Glenn anastomosis using Amplatzer duct occluder.

Additional source of pulmonary blood flow in patients with bidirectional cavopulmonary anastomosis (Glenn shunt) may cause elevation of the pulmonary artery pressure precluding safe completion of the Fontan operation. A case is presented with single-ventricle bidirectional cavopulmonary anastomosis and additional flow from the ventricle to the pulmonary artery resulting in elevated Glenn pressure. The communication was successfully occluded using Amplatzer duct occluder with satisfactory reduction in the Glenn pressure.     

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.     

Outcome of single ventricle and total anomalous pulmonary venous connection

Management of patients with single-ventricle physiology is significantly affected by anomalies of pulmonary venous return at all stages, whether primary palliation, bidirectional Glenn shunt, or completion of Fontan circulation. We treated 25 patients with pulmonary venous anomalies and single ventricle by staged palliation, from June 1996 to May 2005. Visceral heterotaxy with atrial isomerism was present in 19 of them. Primary palliation with a systemic-to-pulmonary artery shunt was undertaken in 15 patients. There were 5 early deaths, of which 4 were due to obstruction of pulmonary venous return. A bidirectional Glenn shunt was constructed in 17 patients including 10 who had it as a primary palliative procedure. There were 7 early deaths after the bidirectional Glenn procedure; only one was due to pulmonary venous obstruction. Five patients attained completion of the Fontan procedure. There was one early death after the Fontan operation. Anomalous pulmonary venous return can significantly complicate the management of patients with single ventricle, with an impact on survival in early infancy. Palliation with the aim of instituting extracardiac conduit Fontan circulation allows greater latitude and more streamlined management.     

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.     

Single-stage versus two-stage modified Fontan procedure

We compared surgical outcomes of the single-stage and two-stage modified Fontan procedures to clarify clinical superiority. Of 28 children undergoing a modified Fontan procedure from October 1995 to October 2005, 15 had a 1-stage and 13 had a 2-stage operation. In the 2-stage group, pulmonary artery growth was evaluated before and after the first stage. Operative mortality was 26.6% in the 1-stage group and 0% in the 2-stage group. The benefits of a previous bidirectional Glenn shunt were decreased cyanosis and volume overload, but there was no significant difference in pulmonary artery growth reflected in pulmonary artery indices before and after the bidirectional Glenn procedure. Older children underwent a 2-stage modified Fontan procedure and had better outcomes in terms of lower mortality, improved oxygen saturation, decreased volume load, and less deterioration of atrioventricular valve regurgitation.     

Longevity of Neonatal Ductal Stenting for Congenital Heart Diseases with Duct‐dependent Pulmonary Circulation

Introduction. Ductal stent (DS) in duct‐dependent pulmonary circulation is less morbid than neonatal Blalock–Taussig shunt. However, there is concern if DS provides an adequately long palliation before definitive repair. Methods. This is a retrospective review of clinical follow‐up of all consecutive infants after successful DS performed by a single operator. They were divided into three anatomic groups. Group A neonates had balloon valvotomy for critical pulmonary stenosis or pulmonary atresia with intact ventricular septum, who needed DS patency until the right ventricle was adequate to provide antegrade pulmonary flows. Group B patients with tetralogy of Fallot and pulmonary atresia suited for later biventricular repair needed ductal patency until conduit surgery was completed. Group C patients with functionally univentricular hearts needed DS patency until bidirectional Glenn shunt completion. Results. Among 22 infants, four Group A patients followed for 26–54 months after balloon pulmonary valvotomy had adequate oxygen saturation and needed only short‐term DS patency. In six out of nine Group B patients, corrective biventricular repair using conduits was performed after 5–14 months at a body weight of 5–7.5 kg. Bidirectional Glenn shunt and confluence repair were performed in seven of nine Group C patients weighing 6–8.5 kg after 8–15 months. The hilar pulmonary artery growth in B and C groups was adequate for surgical repair. No patient needed stent redilatations or additional shunts on follow‐up for hypoxia. Four patients had sudden death. Conclusions. The short‐term patency of DS was adequate after balloon valvotomy for critical pulmonary stenosis or pulmonary atresia with intact ventricular septum. Duration of palliation by DS was also sufficient in univentricular hearts to allow adequate somatic growth before Glenn surgery. In patients with biventricular anatomy treated by DS, conduit repair had to be performed at a relatively early age. Interstage mortality was 18%.     

Clinical application of bidirectional Glenn shunt with off-pump technique

A study was conducted to evaluate the outcomes of the bidirectional Glenn shunt technique performed off-pump. Between April 1999 and April 2001, 36 patients underwent bidirectional Glenn shunt, unilateral in 28 patients and bilateral in 8 patients, without using cardiopulmonary bypass. The patients consisted of 25 males and 11 females with a mean age of 5.7 +/- 5.4 years and a mean body surface area of 0.72 +/- 0.34 m2. Preoperative percutaneous oxygen saturation was 75% +/- 7%, and pulmonary arterial pressure was 14.3 +/- 3.6 mmHg. There was no operative mortality. Chylothorax occurred in 1 patient in the early postoperative period. All the other patients were discharged without complications. Mean arterial oxygen saturation at discharge was 92.7% +/- 4.0%. This shunt technique is easy to perform and is helpful in the early management of patients with a functionally univentricular heart. However, much remains to be learned about this unusual physiological system.     

经皮介入栓堵双向Glenn术后扩张的奇静脉

目的:总结经皮介入栓堵双向Glenn术后扩张奇静脉的结果。方法:8例复杂性先天性心脏病患儿,双向Glenn术后发现奇静脉和/或半奇静脉扩张,平均年龄(7.7±3.3)岁,平均体质量(24±6)kg,距双向Glenn手术1.0～4.7年,平均2.7年。入院时氧饱和度(SO2)平均(0.80±0.08)。心血管造影显示扩张的奇静脉和/或半奇静脉,平均内径(8±2)mm,与上腔静脉内径比值平均0.66±0.14。肺动脉的Mcgoon比值平均2.3±0.3,Nakata指数平均(248±75)mm2/m2,平均肺动脉压(PAP)和上腔静脉压(SCVP)均为(13.4±3.3)mmHg(1 mmHg=0.133 kPa)。1例合并左肺动脉(LPA)起始部中度狭窄。于基础麻醉下经皮导管栓堵奇和/或半奇静脉,1例同时行LPA狭窄部位球囊扩张。结果:栓堵术后SO2升高至平均〔(0.86±0.04),P<0.0001〕,PAP〔(12.9±3.4)mmHg,P=0.53〕和SVCP〔(12.7±3.2)mmHg,P=0.09〕无变化。4例于栓堵术后1 w至1年行全腔静脉-肺动脉连接术(TCPC)。4例随诊1～2年SO2无变化。结论:双向Glenn术后合并奇静脉和/或半奇静脉扩张、SO2降低,但无SCVP或PAP升高者,可经皮介入栓堵奇静脉和/或半奇静脉,以增加肺血流量,提高体循环SO2。     

Venoatrial shunt-assisted cavopulmonary anastomosis

The bidirectional Glenn shunt operation is conventionally performed under cardiopulmonary bypass. Between June 2007 and September 2009, 218 consecutive patients underwent off-pump bidirectional Glenn shunt institution for single ventricle with pulmonary stenosis complex. Their mean age was 4.72 ± 1.80 years (range, 4 months to 6 years) and median weight was 10.12 kg (range, 4.1-19 kg). A temporary shunt was created between the innominate vein and the right atrium, with a 3-way connector for de-airing. Fifty-five patients had bilateral cavae. The mean internal jugular venous pressure on clamping the superior vena cava was 24.69 ± 1.81 mm Hg. Continuous end-tidal CO? and O? saturation were monitored. Adequate oxygen saturation and blood pressure were maintained by optimizing inotropics, volume, and inspired oxygen. The mean duration of ventilation was 10.17 ± 8.96 h (range, 1-73 h). There were no gross neurological complications. Postoperative pleural effusion developed in 6 (2.75%) patients, and 4 (1.83%) had nodal rhythm. Four (1.83%) patients died in the immediate postoperative period due to low cardiac output syndrome. Venoatrial shunt-assisted bidirectional Glenn shunt surgery can be performed safely by optimizing intraoperative management strategies. It is economical and avoids the deleterious effects cardiopulmonary bypass.     

Pulmonary thromboembolism after Fontan operation

The fatal outcome in an eleven-year-old girl, one month after an extra-cardiac Fontan operation is reported. She was diagnosed with tricuspid atresia and had a Blalock Taussig shunt and a bidirectional Glenn procedure. The Fontan operation was performed using a Dacron conduit, fenestrated with a 6 mm Goretex tube. The first week after the operation she received low molecular weight heparin, then it was stopped and aspirin was started. One month after surgery she was admitted to the hospital because of sudden cyanosis, dyspnea, chest pain and syncope. A diagnosis of left pulmonary artery thrombosis without right to left shunt across the fenestrated tube was made. She was carried to the cardiac catheterization laboratory where a mechanical lysis of the thrombi was attempted. A local infusion of rtPA was started without improvement and she died 3 hours later.     

Occlusion of azygos vein via direct percutaneous puncture of innominate vein following cavopulmonary anastomosis

A 2-year-10-month-old boy was diagnosed with a complex congenital heart disease: right atrial isomerism, left superior vena cava (LSVC), complete atrioventricular septal defect, secundum type atrial septal defect, transposition of the great arteries with pulmonary atresia, patent ductus arteriosus, absence of a right superior vena cava (RSVC), and dextrocardia. He had received a left Blalock-Taussig (BT) shunt at the age of 3 months and a left bidirectional Glenn shunt one year after BT shunt. Progressive cyanosis was noted after the second operation and cardiac catheterization showed a functional Glenn shunt with an engorged azygos vein, which was inadvertently skipped for ligation. Because of the absence of RSVC, transcatheter occlusion of the azygos vein was performed successfully via direct puncture of the innominate vein.     

An Unusual Case of Congenitally Unguarded Tricuspid Valve Orifice Associated with Pulmonary Valve Atresia and Intact Ventricular Septum

We report on a premature neonate who presented with cyanosis soon after birth. She was found on echocardiography to have an unguarded tricuspid valve orifice associated with pulmonary valve atresia and an intact interventricular septum. Owing to the small‐sized pulmonary arteries, she was initially managed conservatively with prostaglandin infusion, and at one year of age underwent a successful bidirectional cavo‐pulmonary (Glenn) shunt operation. (ECHOCARDIOGRAPHY 2010;27:202‐204)     

Occlusion of a Sano shunt using the amplatzer duct occluder

The presence of a residual systemic-to-pulmonary shunt following a bidirectional Glenn operation may be necessary in patients with an elevated pulmonary vascular resistance. It is often possible to perform percutaneous occlusion of these shunts once the resistance has fallen. We report on the use of an Amplatzer Ductal Occluder Device to occlude a residual Sano shunt in an infant with a variant of hypoplastic left heart syndrome.     

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.     

Management algorithm in pulmonary atresia with intact ventricular septum.

Pulmonary atresia with intact ventricular septum (PAIVS) is a disease with remarkable morphologic variability, affecting not only the pulmonary valve but also the tricuspid valve, the RV cavity and coronary arteries. With advances in interventional techniques and congenital heart surgery, the management of PAIVS continues to evolve. This review is an attempt at providing a practical approach to the management of this disease. The basis of our approach is morphologic classification as derived from echocardiography and angiography. Group A, patients with good sized RV and membranous atresia, the primary procedure at presentation is radiofrequency (RF) valvotomy. Often it is the only procedure required in this group with the most favourable outcome. Patients with severely hypoplastic RV (Group C) are managed along the lines of hearts with single ventricle physiology. The treatment at presentation is patent ductus arteriosus (PDA) stenting with balloon atrial septostomy or conventional modified Blalock Taussig (BT) shunt. Bidirectional Glenn shunt may be done 6-12 months later followed by Fontan completion after a suitable interval. Patients in Group B, the intermediate group, are those with borderline RV size, usually with attenuated trabecular component but well developed infundibulum. The treatment at presentation is RF valvotomy and PDA stenting +/- balloon atrial septostomy. Surgical re-interventions are not uncommonly required viz. bidirectional Glenn shunt when the RV fails to grow adequately (11/2 - ventricle repair) and right ventricular outflow tract (RVOT) reconstruction for subvalvar obstruction or small pulmonary annulus. Catheter based interventions viz. repeat balloon dilatation or device closure of patent foramen ovale (PFO) may also be required in some patients.