Reconstruction of cavopulmonary pathway for the patient with persistent arteriovenous malformations due to offset flow from hepatic vein

The hypoxemia caused by arteriovenous malformations after cavopulmonary shunt in patients with heterotaxy, an interrupted inferior vena cava and single ventricle physiology have been treated by incorporation of hepatic vein flow into the pulmonary circulation. However, some patients have persistent arteriovenous malformations because of offset hepatic venous flow to one pulmonary artery. Various approaches have been used to change offset flow to achieve balanced hepatic flow to the lungs in this patient population. This case report highlights the challenges that may be associated with anastomosis of the azygos vein to the inferior vena cava at the level of the diaphragm and illustrates an alternative technique to direct hepatic venous blood into an affected lung with arteriovenous malformations. The redirection of hepatic venous flow to the affected pulmonary artery resulted in resolution of symptoms within months of surgery.     

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.     

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.     

Abnormal distribution of pulmonary blood flow after the Glenn shunt or Fontan procedure: risk of development of arteriovenous fistulae

Since the Fontan procedure results in low pulsatile pulmonary blood flow similar to that seen in patients with a Glenn shunt, it may also be associated with abnormal distribution of flow to the lower lung lobes and with the development of pulmonary arteriovenous fistulae (PAVF). In 12 patients 0.8 to 4.5 years after Fontan procedure and in 20 patients 0.2 to 18 years after receipt of Glenn shunts we assessed ventilation (with 133Xe) and perfusion (after a peripheral injection of 99mTc-macroaggregated albumin) to compare upper to lower lobe distribution of blood flow with that in a control group. The presence of PAVF was assessed by radionuclide activity in kidneys and the brain and by a two-dimensional echocardiographic contrast study. A decreased upper/lower lobe perfusion ratio was noted in 13 of 20 patients with Glenn shunts (65%) and correlated with the time after surgery (p less than .05). Despite the shorter follow-up period, two of 12 (16%) patients who had undergone the Fontan procedure also had a decreased upper/lower lobe perfusion ratio, and one of these developed right heart failure. Brain and kidney radionuclide counts above control values were observed in all patients with Glenn shunts and in 11 of 12 patients who had the Fontan operation. However, in only five of 20 (25%) patients with Glenn shunts were PAVF confirmed by the two-dimensional echocardiographic contrast study. Three of the five patients with PAVF had Glenn shunts of long duration.(ABSTRACT TRUNCATED AT 250 WORDS)     

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     

An Unusual Cause of Irritability in a Single Ventricle Patient after Bidirectional Glenn Shunt

The differential diagnosis for irritability in children is broad. In patients with congenital heart disease, one must strongly consider cardiac etiologies such as low cardiac output or elevated central venous pressure (CVP). In patients with single-ventricle physiology, the second stage of palliation includes bidirectional Glenn, which involves anastomosis of the superior vena cava to the pulmonary artery resulting in volume offloading of the single systemic ventricle. Typically, early in the post-operative period, patients may experience a headache due to the acute increase in CVP, and symptoms improve over time. Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a rare neurologic disorder in children, characterized by raised intracranial pressure (ICP) in the absence of brain parenchymal lesions or cerebrospinal fluid (CSF) abnormalities. While the pathogenesis of IIH is unknown, early recognition and treatment of IIH are important to prevent permanent vision loss. There are only rare reports of IIH in patients with Fontan circulation. To our knowledge, we report the first case of IIH in a 2-year-old female after bidirectional Glenn.     

Congenital Portosystemic Venous Connections and Other Abdominal Venous Abnormalities in Patients with Polysplenia and Functionally Univentricular Heart Disease: A Case Series and Literature Review

Objective. Published case reports suggest that congenital portosystemic venous connections (PSVC) and other abdominal venous anomalies may be relatively frequent and potentially important in patients with polysplenia syndrome. Our objective was to investigate the frequency and range of portal and other abdominal systemic venous anomalies in patients with polysplenia and inferior vena cava (IVC) interruption who underwent a cavopulmonary anastomosis procedure at our center, and to review the published literature on this topic and the potential clinical importance of such anomalies. Design. Retrospective cohort study and literature review were used. Results. Among 77 patients with heterotaxy, univentricular heart disease, and IVC interruption who underwent a bidirectional Glenn and/or modified Fontan procedure, pulmonary arteriovenous malformations were diagnosed in 33 (43%). Bilateral superior vena cavas were present in 42 patients (55%). Despite inadequate imaging in many patients, a partial PSVC, dual IVCs, and/or renal vein anomalies were detected in 15 patients (19%). A PSVC formed by a tortuous vessel running from the systemic venous system to the extrahepatic portal vein was found in six patients (8%). Abdominal venous anomalies other than PSVC were documented in 13 patients (16%), including nine (12%) with some form of duplicated IVC system, with a large azygous vein continuing to the superior vena cava and a parallel, contralateral IVC of similar or smaller size, and seven with renal vein anomalies. In patients with a partial PSVC or a duplicate IVC that connected to the atrium, the abnormal connection allowed right‐to‐left shunting. Conclusions. PSVC and other abdominal venous anomalies may be clinically important but under‐recognized in patients with IVC interruption and univentricular heart disease. In such patients, preoperative evaluation of the abdominal systemic venous system may be valuable. More data are necessary to determine whether there is a pathophysiologic connection between the polysplenia variant of heterotaxy, PSVC, and cavopulmonary anastomosis‐associated pulmonary arteriovenous malformations.     

一期或分期全腔静脉-肺动脉连接术治疗功能性单心室

目的总结、比较一期和分期全腔静脉-肺动脉连接术(total cavopulmonary connection,TCPC)治疗复杂先天性心脏病的疗效。方法分析2003年12月至2007年9月在广东省人民医院住院,适合一期生理矫治并施行了一期TCPC术的患儿25例和已先期完成第一阶段姑息手术并施行了二期TCPC术的患儿17例的临床资料。前期手术包括15例双向Glenn手术、1例体-肺分流术、1例三尖瓣下移畸形矫治加双向Glenn手术。一期TCPC组中14例采用外管道,11例肺动脉直接下拉与下腔静脉吻合。二期TCPC组中15例采用外管道,1例采用心房内通道,1例肺动脉直接与下腔静脉吻合。结果早期死亡4例,病死率9.5%(4/42)。一期TCPC组死亡3例,病死率12.0%(3/25);二期TCPC组死亡1例,病死率5.9%(1/17)。二期TCPC组的辅助通气时间、胸管停留时间、住监护室时间、术后住院天数比一期TCPC组短,但差异无统计学意义(P0.05)。随访8个月到4.8年。1例于术后8个月死于严重的房室瓣反流、心力衰竭。结论一期和分期TCPC手术治疗复杂先心病都能达到良好的效果。     

One-Stage Correction with Intra- and Extraatrial Rerouting of Anomalous Systemic and Pulmonary Venous Return and Intraventricular Repair of Double Outlet Right Ventricle in a Patient with Heterotaxy Syndrome

We report a very rare case of successful intracardiac correction in a patient with heterotaxy syndrome. The cardiac malformations included dextrocardia, double outlet right ventricle, pulmonary stenosis, interrupted inferior vena cava, hemiazygos continuation and total anomalous pulmonary venous return. One-stage correction was performed. The atrial procedure consisted of intra- and extraatrial rerouting of the anomalous systemic and pulmonary venous return. The hepatic veins were detached and diverted to the left atrium via an extracardiac conduit. The correction of the double outlet right ventricle was accomplished by intraventricular redirection of the blood flow from the left ventricle to the aorta. The right ventricular outflow was ultimately remodeled using a valved conduit. For better perception of the complex morphology, a three-dimensional model was designed, using CT scan images. This proved to be very useful for surgical planning, especially with regard to the intraatrial reconstruction of the systemic and pulmonary venous rerouting.     

Inferior vena caval return to the left atrium with intact interauricular septum. Apropos of 2 cases surgically treated with success

Two cases of abnormal inferior vena caval return to the left atrium are reported in a 9 year old boy and 13 year old girl. The diagnosis was suspected on the finding of severe cyanosis alone, and the anomalous systemic venous return was correctly identified by angiography of the inferior vena cava. There were three angiographic points of interest in these two cases: the normal position of the inferior vena cava, the absence of a left-to-right interatrial shunt and the presence of a vertical intra-left atrial "membrane" inserted behind the orifice of the inferior vena cava. Surgical correction consisted in resecting the inferior part of the interatrial septum and reconstructing a new septum behind the orifice of the inferior vena cava with a dacron patch in one case and by direct suture in the other. The good surgical result was controlled by angiography in both cases. In the second case, an intrapulmonary shunt due to multiple arteriovenous fistulae demonstrated by contrast echocardiography was responsible for persistent mild cyanosis for a few months after surgery. The long-term clinical results were excellent in both cases. The authors review the literature of this rare malformation due to persistence of part of the right valve of the sinus venosus.     

Interventional therapy of large veno-venous collaterals after univentricular palliation for congenital heart disease using the Starflex- and Amplatzer- PDA occluder

Arterial hypoxemia is frequently observed after Fontan-like palliation of congenital heart defects. Whereas small systemic-to-pulmonary venous collaterals can easily be occluded by use of metal spirals, large collateral vessels may be therapeutically challenging. We report on two patients with arterial hypoxemia (transcutaneous oxygen saturations 72% and 82%, respectively) after Fontan-like operation. One patient was diagnosed with double inlet left ventricle, malposition of the great arteries and subaortic obstruction; another patient was diagnosed with mitral atresia, double-outlet right ventricle, malposition of the great arteries and hemiazygos continuity. In the first patient, a large venous collateral (measuring 16 mm in diameter) was observed connecting the superior vena cava and the right upper pulmonary vein. In the latter patient, hepatic fistulas drained systemic venous blood into an excluded hepatic vein. There was an associated patent fenestration of the conduit connecting the hepatic veins to the pulmonary artery. After occlusion of the supracardiac venous collateral with a 33 mm Starflex device, arterial oxxgen saturation rose to levels above 95%. The excluded hepatic vein was occluded with of an 10/8 mm Amplatzer PDA occluder and the fenestration was closed with a 17 mm Starflex device. Arterial oxygen saturations rose to 98%. CONCLUSION: Occlusion of large collateral vessels after Fontan-like palliation of congenital heart defects can be effectively performed using the Amplatzer PDA device and the Starflex device. Different occlusion devices are needed to address the morphological differences of the collateral vessels.     

Percutaneous transcatheter closure of a large systemic to pulmonary venous fistulae in an adult patient after extracardiac fontan

Vascular fistulae are frequent complications in patients who have undergone a Fontan operation for palliation of single ventricle physiology. Fistulae involving the pulmonary vasculature may result in progressive hypoxemia, pulmonary hemorrhage, and clinical symptoms. These are commonly managed by percutaneous transcatheter embolization utilizing coils, and more recently, vascular plugs and septal occluders. We present a clinical case of an adult patient who underwent an extracardiac Fontan procedure in childhood for univentricular physiology and presented with symptoms of systemic desaturation 10 years after his surgery. The patient was found to have a large fistula from the inferior vena cava to the right inferior pulmonary vein. The fistula was attempted to be closed with a 12 mm Amplatzer Septal Occluder (St. Jude Medical, St. Paul, MN). Angiography showed continued flow across the fistula, which was then successfully occluded with an 18 mm Amplatzer “Cribriform” Septal Occluder (St. Jude Medical, St. Paul, MN). The patient experienced immediate improvement in his systemic saturation, and demonstrates continued resolution of his symptomatic hypoxia on follow‐up. This case illustrates an uncommon systemic to pulmonary vein fistula after Fontan, and a unique, successful embolization with two septal occluders, resulting in sustained symptomatic improvement. © 2015 Wiley Periodicals, Inc.     

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.     

Late systemic desaturation after total cavopulmonary shunt operations.

OBJECTIVES--To assess the medium-term results of total cavopulmonary shunt operations in children with left atrial isomerism, interrupted inferior vena cava, and complex congenital heart defects. BACKGROUND--Creation of a total cavopulmonary shunt provides very good interim palliation for children with interrupted inferior vena cava and complex congenital heart disease; however, longer term results after this operation have not been reported. METHODS--Detailed follow up of six children who underwent creation of a total cavopulmonary shunt at a tertiary referral centre. RESULTS--There were no early or late deaths. Oxygen saturations at discharge ranged from 89% to 92% (mean 90%). At last follow up (mean 4.7 years) saturations at rest ranged from 73% to 81% (mean 77%) (P < 0.05). All patients underwent exercise stress testing. At peak exercise oxygen saturations ranged from 62% to 87% (mean 71.5%) and during recovery from 68% to 85% (mean 78%). Cardiac catheterisation was performed in five patients with saturations of less than 80% at rest or peak exercise. No patient had pulmonary arteriovenous fistula. Systemic venous to hepatic venous collaterals were documented in four patients. These were localised below the diaphragm in three and above the diaphragm in one patient. The collateral vessel was successfully embolised in three of these patients, with a rise in resting oxygen saturations from 6 to 10% (mean 7%). CONCLUSIONS--The development of systemic venous to hepatic venous collaterals is a common complication in patients who undergo a total cavopulmonary shunt operation. This can lead to significant desaturation at rest and during exercise. Detailed angiographic studies of the infradiaphragmatic system veins is required for diagnosis. Transcatheter embolisation of such vessels gives good relief.     

双向格林术后心血管造影特征分析

目的 分析双向格林术后并发症及心血管造影特征,为临床治疗提供依据.方法 38例先天性心脏病双向格林术后患者(男性24例,女性14例)接受心血管造影检查.年龄(7.8±5.6)岁,双向格林术至造影间隔时间为(4.1±1.9)年.所有患者均行上腔静脉及肺动脉造影,并测量肺动脉-上腔静脉连续压力.结果 38例患者肺动脉平均压力为(14.8±4.5)mm Hg(1 mm Hg=0.133kPa),上腔静脉平均压力为(15.4±5.4)mm Hg;肺动脉到上腔静脉连续测压均无压力阶差.其中9例出现肺动脉压力升高,年龄为(6.6±4.7)岁,其上腔静脉平均压力为(22.9±5.1)mm Hg,肺动脉平均压力为(21.5±2.9)mm Hg.心血管造影提示14例患者[年龄(7.9±4.6)岁]出现静脉侧支血管,其中2例成功行经导管封堵术.侧支血管组上腔静脉压力[(17.8±7.2)mmHg比(14±3.6)mm Hg,P＜0.05]及肺动脉压力[(16.7±5.7)mm Hg比(13.7±3.4)mm Hg,P＜0.05]均高于无侧支血管组(n=24).14例静脉侧支血管分布:后纵隔侧支12例,其中合并前纵隔侧支3例,合并中纵隔侧支1例;单独中纵隔侧支血管2例.2例患者肺动静脉瘘形成,其中单发囊状瘘和多发动静脉瘘各1例.2例患者存在体肺动脉侧支血管,均成功行经导管栓塞术.结论 双向格林术可引起多种并发症,心血管造影检查能够早期发现并指导治疗.     

Masked abnormal drainage of the inferior vena cava into the left atrium

A 6 year old boy with a large atrial septal defect, partial anomalous pulmonary venous drainage and unrecognized anomalous insertion of the inferior vena cava into the left atrium had cyanosis after closure of the atrial defect. Repeat study revealed direct drainage of the inferior vena cava into the left atrium with moderate arterial oxygen desaturation. At repeat operation an unusual positioning of the inferior vena cava was seen. After reopening of the atrial defect, the pulmonary venous and systemic venous drainage anomalies were identified. A Dacron patch was inserted so as to divert flow to the proper atrium. Repeat catheterization 3 months after operation revealed a normal heart with no obstruction; arterial oxygen saturation was normal. The child has continued to do well 3 years after operation.     

Intraoperative massive pulmonary tumor embolism from clear cell sarcoma in the retroperitoneum: successful treatment using cardiopulmonary bypass

Malignant neoplasms rarely extend into the inferior vena cava and up to the right side of the heart. Although massive pulmonary tumor embolism occurs relatively rarely, it can be a catastrophic problem. Intraoperative pulmonary tumor embolism and cardiac arrest occurred in a 68-year-old woman while dissecting the inferior vena cava to resect a pararenal tumor extending into the retrohepatic inferior vena cava. Abrupt arterial hypotension, tachycardia, and increased central venous pressure lead to the diagnosis of massive pulmonary tumor embolism. Emergency cardiopulmonary bypass was commenced under profound hypothermia and cardiac arrest. The tumors in the main pulmonary artery were extracted, and fragments of remnant tumor were retrieved by a vascular endoscope, a Fogarty catheter, and milking of the lung. Following embolectomy, the tumor in the retrohepatic to infrarenal inferior vena cava was removed and the primary tumor together with the infrarenal inferior vena cava was resected under hepatic vascular exclusion and partial cardiopulmonary bypass. The inferior vena cava below the renal veins was not reconstructed. The patient recovered with slight retrograde amnesia. A postoperative pulmonary perfusion scintigram showed no defect in the pulmonary circulation. She is well now 8 months after surgery. Safe prevention measures should be accomplished as a part of the perioperative management of patients with inferior vena cava tumor thrombus that may be fragile, and cardiopulmonary bypass should always be stand-by on surgery.     

Univentricular heart and pulmonary stenosis with a right-to-left shunt between the innominate and pulmonary veins after Glenn operation: a case report

A 12-year-old girl with a univentricular heart and pulmonary stenosis, who had undergone Glenn operation at two years of age and Fontan operation at 11 years of age, had a right-to-left shunt via collaterals between the innominate and pulmonary veins. This right-to-left shunt was detected by two-dimensional contrast echocardiography. The contrast material was injected into the left antecubital vein appeared in the left atrium, and this was confirmed by innominate venography. The contrast material injected into the left innominate vein passed via the collaterals into the pulmonary veins bilaterally. No such cases have so far been reported. In our experience, in four of six cases after Glenn operation, including the present case, the abnormal collateral circulation from the superior vena cava to the atrium was detected by two-dimensional contrast echocardiography. This case is interesting embryologically and suggests that the connection between the pulmonary and systemic veins which is present in early fetal life, and subsequently disappears, was present after birth.     

An unusual opacity of the right base

The scimitar syndrome or pulmonary venolobar syndrome is a rare, complex and variable malformation of the right lung characterized by an abnormal right sided pulmonary venous drainage in the inferior vena cava, malformation of the right lung, abnormal arterial supply and sometimes cardiac malformations. We present a case in which this diagnosis was suspected on an abnormal routine chest radiograph in a 38-year-old asymptomatic woman. Most patients are asymptomatic; symptomatic patients have a marked left-to-right shunt or a severe congenital heart disease. They usually suffer from shortness of breath, asthenia or repeated chest infections. Usually, the posteroanterior chest radiograph can confirm the diagnostic. It shows the abnormal vein draining into the inferior vena cava as a curved vascular shadow with a scimitar like appearance. However, in some cases, when the scimitar vein is masked by the overlying cardiac shadow, computed tomography, angiography and magnetic resonance imaging can be helpful by showing the abnormal vein and its insertion into the inferior vena cava. Scimitar syndrome seldom necessitates surgical intervention. However, repeated lung infections can sometimes require lobectomy or pneumonectomy, left-to-right shunt vascular surgery to redirect the scimitar vein into the left atrium.