Fetal Pulmonary Venous Return: From Basic Research to the Clinical Value of Doppler Assessment

The fetal pulmonary circulation represents less than 25% of the fetal cardiac output. In comparison with the pulmonary arteries, studies on pulmonary veins are few and limited, and many questions remain to be answered. The literature reports that pulmonary veins play an important role in regulating vascular flow, forming an active segment of the pulmonary circulation. The development of more sophisticated ultrasonography technology has allowed the investigation of the extraparenchymal pulmonary veins and their waveform. The recognition of the pulmonary vein anatomy in echocardiography is important for the diagnosis of anomalous pulmonary venous connections, with a significant impact on prognosis. On the other hand, the identification of the normal pulmonary vein waveform seems to be a reliable way to study left heart function, with potential applicability in fetal and maternal pathology. Thus, the goal of this narrative review was to provide a clinically oriented perspective of the available literature on this topic.

A Risk Prediction Model for Reintervention After Total Anomalous Pulmonary Venous Connection Repair

BACKGROUND

Outcomes after total anomalous pulmonary venous connection (TAPVC) repair remain suboptimal due to recurrent pulmonary vein (PV) obstruction requiring reinterventions. We sought to develop a clinical prediction rule for PV reintervention after TAPVC repair.

METHODS

Data from consecutive patients who underwent TAPVC repair at a single institution from January 1980 to January 2020 were retrospectively reviewed after Institutional Review Board approval. The primary outcome was postdischarge (late) unplanned PV surgical or transcatheter reintervention. Echocardiographic criteria were used to assess PV residual lesion severity at discharge (class 1: no residua; class 2: minor residua; class 3: major residua). Competing risk models were used to develop a weighted risk score for late reintervention.

RESULTS

Of 437 patients who met entry criteria, there were 81 (18.5%) reinterventions at a median follow-up of 15.6 (interquartile range, 5.5-22.2) years. On univariable analysis, minor and major PV residua, age, single-ventricle physiology, infracardiac and mixed TAPVC, and preoperative obstruction were associated with late reintervention (all P < .05). The final risk prediction model included PV residua (class 2: subdistribution hazard ratio [SHR], 4.8; 95% CI, 2.8-8.1; P < .001; class 3: SHR, 6.4; 95% CI, 3.5-11.7; P < .001), age <1 year (SHR, 3.3; 95% CI, 1.3-8.5; P = .014), and preoperative obstruction (SHR, 1.8; 95% CI, 1.1-2.8; P = .015). A risk score comprising PV residua (class 2 or 3: 3 points), age (neonate or infant: 2 points), and obstruction (1 point) was formulated. Higher risk scores were significantly associated with worse freedom from reintervention (P < .001).

CONCLUSIONS

A risk prediction model of late reintervention may guide prognostication of high-risk patients after TAPVC repair.

Multimodality diagnostic imaging for anomalous pulmonary venous connections: a pictorial essay

Anomalous pulmonary venous connections represent a heterogeneous group of congenital heart diseases in which a part or all pulmonary venous flow drains directly or indirectly into the right atrium. Clinically, anomalous pulmonary venous connections may be silent or have variable consequences, including neonatal cyanosis, volume overload and pulmonary arterial hypertension due to the left-to-right shunt. Anomalous pulmonary venous connections are frequently associated with other congenital cardiac defects and their accurate diagnosis is crucial for treatment planning. Therefore, multimodality diagnostic imaging, comprising a combination (but not all) of echocardiography, cardiac catheterization, cardiothoracic computed tomography and cardiac magnetic resonance imaging, helps identify potential blind spots relevant to each imaging modality before treatment and achieve optimal management and monitoring. For the same reasons, diagnostic imaging evaluation using a multimodality fashion should be used after treatment. Finally, those interpreting the images should be familiar with the various surgical approaches used to repair anomalous pulmonary venous connections and the common postoperative complications.

An analysis of the left top pulmonary vein and comparison with the right top pulmonary vein for lung resection by three-dimensional CT angiography and thin-section images

PURPOSE

The right top pulmonary vein (RTPV) is defined as an anomalous branch of the right superior PV (SPV) draining into the PV or left atrium (LA). Several previous reports have described the RTPV, but only a few have mentioned the left top PV (LTPV). The present study aimed to evaluate the branching patterns of the RTPV and LTPV using thin-section CT images and three-dimensional CT angiography (3D-CTA).

MATERIALS AND METHODS

This study included 1437 consecutive patients for evaluation of the right side and 1454 consecutive patients for the left side who were suspected of lung cancer and underwent CTA. We assessed the presence of each RTPV and LTPV and their branching patterns on the CTA images. When the RTPV or LTPV was identified, the maximum short-axis diameter was measured.

RESULTS

RTPV was found in 9.1% (131/1437), whereas LTPV was found in 2.9% (42/1454) of the patients. RTPV was also observed in 17.1% (7/41) of LTPV cases, except for one case in which the right side could not be evaluated. The most common RTPV inflow site was the right inferior PV (IPV) in 64.9% (85/131) of the patients, whereas that of the LTPV was the left IPV in 100.0% (42/42) of the patients. The mean diameter of the RTPV and LTPV was 3.3 mm (range, 1.3-7.5 mm) and 2.4 mm (range, 0.9-6.3 mm), respectively (P < 0.01).

CONCLUSION

The top PV branching pattern variations can be evaluated using thin-section CT and 3D-CTA images. RTPV is not a rare finding, and LTPV should also be identified in lung cancer cases scheduled for resection.

Intracardiac total anomalous pulmonary venous return or septum primum malposition? Complete repair in left atrial isomerism

Total anomalous pulmonary venous return due to septum primum malposition is a poorly understood condition despite being very common in left atrial isomerism or polysplenia syndrome. Due to the leftward displacement of the septum primum, either the two right pulmonary veins or all four pulmonary veins can drain abnormally into the right atrium, despite their correct position. In other words, the four pulmonary veins (or the two right pulmonary veins), looking from outside the heart, return at the back of the atrium in the normal position. Nevertheless, from the inside of the heart, two or all four pulmonary veins drain into the right atrium due to the leftward displacement of the septum primum. As an example, we report a 5-month-old patient with severe malposition of the septum primum and consequent total anomalous pulmonary venous drainage into the right atrium. The patient underwent surgical correction with resection of the malpositioned septum primum and reconstruction of a normal interatrial septation with a pericardial patch.

Computed tomographic parenchymal lung findings in premature infants with pulmonary vein stenosis

BACKGROUND

Developmental pulmonary vein pulmonary vein stenosis in the setting of prematurity is a rare and poorly understood condition. Diagnosis can be challenging in the setting of chronic lung disease of prematurity. High-resolution non-contrast chest computed tomography (CT) is the conventional method of evaluating neonates for potential structural changes contributing to severe lung dysfunction and pulmonary hypertension but may miss pulmonary venous stenosis due to the absence of contrast and potential overlap in findings between developmental pulmonary vein pulmonary vein stenosis and lung disease of prematurity.

OBJECTIVE

To describe the parenchymal changes of pediatric patients with both prematurity and pulmonary vein stenosis, correlate them with venous disease and to describe the phenotypes associated with this disease.

MATERIALS AND METHODS

A 5-year retrospective review of chest CT angiography (CTA) imaging in patients with catheterization-confirmed pulmonary vein stenosis was performed to identify pediatric patients (< 18 years) who had a history of prematurity (< 35 weeks gestation). Demographic and clinical data associated with each patient were collected, and the patients' CTAs were re-reviewed to evaluate pulmonary veins and parenchyma. Patients with post-operative pulmonary vein stenosis and those with congenital heart disease were excluded. Data was analyzed and correlated for descriptive purposes.

RESULTS

A total of 17 patients met the inclusion criteria (12 female, 5 male). All had pulmonary hypertension. There was no correlation between mild, moderate, and severe grades of bronchopulmonary dysplasia and the degree of pulmonary vein stenosis. There was a median of 2 (range 1-4) diseased pulmonary veins per patient. In total, 41% of the diseased pulmonary veins were atretic. The right upper and left upper lobe pulmonary veins were the most frequently diseased (n = 13/17, 35%, n = 10/17, 27%, respectively). Focal ground glass opacification, interlobular septal thickening, and hilar soft tissue enlargement were always associated with the atresia of an ipsilateral vein.

CONCLUSION

Recognition of the focal parenchymal changes that imply pulmonary vein stenosis, rather than chronic lung disease of prematurity changes, may improve the detection of a potentially treatable source of pulmonary hypertension, particularly where nonangiographic studies result in a limited direct venous assessment.

Anomalous systemic venous connection to left atrium in a heart with usual atrial arrangement

Anomalous systemic venous connection to left atrium is rare anomaly. Previously published cases described this anatomy in patients with left isomerism. Depending on the size of the atrial septal defect, patients usually present with varying degrees of cyanosis and right heart hypoplasia. Here, we report a case of anomalous systemic venous connection to left atrium in a newborn with the usual atrial arrangement.

The Shunt of It

Pulmonary arteriovenous malformations (PAVMs) are rare and most often identified in patients with hereditary hemorrhagic telangiectasia (HHT). We describe a patient with severe hypoxemia and orthodeoxia with imaging findings consistent with PAVMs. Resected lung pathologic findings confirmed the presence of numerous microscopic vascular abnormalities within the right lower lobe that was consistent with diffuse pulmonary arteriovenous shunts. Family history was negative for HHT but was positive for pulmonary arterial hypertension (PAH) in two second-degree relatives. A vascular malformation gene panel was negative for genes that commonly are associated with HHT but identified a pathogenic variant in the gene encoding bone morphogenetic protein receptor-2 (BMPR2 p.Cys123∗). Pathogenic variants in BMPR2 are a well-known cause of hereditary PAH; there have been several reports to date of patients with PAVMs and PAH. However, this is the first patient to be reported with a pathogenic variant in BMPR2 to have PAVMs in isolation.

Fetal left-atrial posterior-space-to-diagonal ratio at 17-37 weeks' gestation for prediction of total anomalous pulmonary venous connection

OBJECTIVES

To develop normative data for the left-atrial posterior-space-to-diagonal (LAPSD) ratio and post-left atrium space (PLAS) index in fetuses from 17 to 37 weeks' gestation, and determine the optimal cut-offs of the LAPSD ratio and PLAS index to discriminate between normal fetuses and those with total anomalous pulmonary venous connection (TAPVC).

METHODS

This was a prospective cross-sectional assessment of 428 structurally normal fetuses between 17 and 37 weeks' gestation and a retrospective study of 27 TAPVC fetuses. The fetal LAPSD ratio was calculated by dividing the left atrium-descending aorta distance (LDD) by the left atrial diagonal diameter (LA). The PLAS index was calculated as the ratio of the LDD to the descending aorta diameter (DA). Pearson's correlation analysis was used to examine the correlation of cardiac parameters with gestational age (GA) and fetal somatic growth. The PLAS index and LAPSD ratio were compared between the normal and TAPVC groups to assess their usefulness in the prenatal diagnosis of TAPVC.

RESULTS

LDD, LA and DA measures showed moderate to strong positive correlation, whereas both the LAPSD ratio and PLAS index showed a slight decrease with increasing GA and biometric variables. The fetal LAPSD ratio and PLAS index in TAPVC cases were significantly greater compared with those of fetuses with a normal heart (both P < 0.001). There were no significant differences in the PLAS index and LAPSD ratio between the isolated and complex TAPVC groups (both P = 1). No significant associations of the PLAS index and LAPSD ratio with fetal gender, four-chamber view type (apical, basal or lateral) or TAPVC type were found. Using values of ≥ 0.35 for the LAPSD ratio and of ≥ 1 for the PLAS index exhibited similar excellent diagnostic performance, with a sensitivity of 100% and specificity of 97.0% or 95.1% for detecting TAPVC.

CONCLUSIONS

Our study demonstrates that the LAPSD ratio is a practical and effective screening tool for diagnosing fetal TAPVC, similar to the PLAS index. Incorporating these parameters into routine cardiac scanning may enhance the prenatal detection of TAPVC. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Better Late Than Never – A Case of a Congenital Left Partial Anomalous Pulmonary Venous Drainage Diagnosed and Treated in The Sixth Decade of Life

Partial anomalous pulmonary venous drainage (PAPVD) is a relatively uncommon cardiac anomaly. The diagnosis might be challenging as are the presenting symptoms. Its clinical course mimics more familiar diseases, e.g., pulmonary artery embolism. We present a case of PAPVD, which had been misdiagnosed for more than two decades. After establishing the correct diagnosis, the patient got his congenital anomaly surgically corrected and showed excellent cardiac recovery in the six months follow up.

Surgical and Cardiac Catheterization Outcomes of Scimitar Syndrome Patients: A Three Decade Single-Center Experience

Scimitar syndrome (SS) is a rare congenital condition which includes partial anomalous pulmonary venous return (PAPVR) and a variable degree of pulmonary hypoplasia. We describe the clinical features, therapeutic approach and outcomes of patients who underwent cardiac catheterization and/or surgical repair of the scimitar vein at a single institution in the United States. This retrospective cohort study included all patients with SS who underwent scimitar vein surgical repair or cardiac catheterization from October 1989 through August 2021 in a tertiary care center. A total of 84 patients with SS were included and median follow-up time was 74 months. Patients diagnosed with SS under the age of one year had a significantly greater incidence of congenital heart defects (CHD) (p < 0.001), non-cardiac anomalies (p = 0.02), pulmonary hypertension (p = 0.02), and mortality (p = 0.04) compared to those diagnosed over the age of 1 year. Twenty-eight patients underwent surgical repair of the scimitar vein. Overall, eight (10%) patients died. Compared to surviving patients, deceased patients had a significantly higher incidence of pulmonary hypertension (PH), neonatal SS diagnosis, and extracorporeal membrane oxygenation (ECMO) support. Median scimitar vein pressure (20 mmHg) of deceased patients was significantly higher compared to pressures in surviving patients (11 mmHg; p = 0.02). PH, CHD, neonatal SS diagnosis, ECMO support, and markedly elevated scimitar vein pressure are associated with mortality. Scimitar vein surgical repair during infancy is commonly associated with PH and restenosis that requires re-intervention.

Diagnosis and Management of Persistent Pulmonary Arterio-venous Malformations following Embolotherapy

Embolotherapy is the primary treatment for pulmonary arterio-venous malformations (PAVMs). Approximately, 2-25% of PAVMs demonstrate persistence following embolization. Early identification and treatment of persistent PAVMs are critical to mitigating life threatening complications. The presence of prior embolic devices and complex angioarchitecture of persistent PAVMs pose technical challenges during repeat embolotherapy. In this article, we review patterns of persistence, factors affecting the persistence, endovascular treatment techniques, and outcomes.

Pulmonary Venous Gradients in Healthy Controls and Following the Repair of Total Anomalous Pulmonary Venous Return

The percent of children who can achieve a normal and physiologic pulmonary venous gradient and flow following the repair of Total Anomalous Pulmonary Venous Return (TAPVR) is not known. Pulmonary venous confluence gradients from infants with supra-, infra-, or mixed TAPVR, repaired using a direct anastomotic connection were measured. Data from age, weight, and gender-matched controls established the normal pulmonary venous gradient range (0.30-0.94 mmHg). TAPVR subjects were divided into three groups: (I) pulmonary venous gradient < 2 × normal with multiphasic flow (II) pulmonary venous gradient > 2 × normal with multiphasic flow, and (III) pulmonary venous gradient > 2 × normal with monophasic flow. From 63 children following TAPVR repair and 63 matched controls, pulmonary venous gradients were significantly lower [0.5 mmHg (IQR:0.4, 0.6) vs 1.6 mmHg (IQR:1.0, 2.4); p < 0.001], and multiphasic flow more frequent (100 vs. 84.1%; p = 0.001) within the control group. There were 38 children (60.3%) in group I, 15 (23.8%) in group II, and 10 (15.8%) in group III. Children in Group I were significantly older at the time of repair, had shorter cardiopulmonary bypass times, and did not utilize deep hypothermic circulatory arrest (DHCA). Multivariate analysis confirmed that avoiding DHCA [Odds Ratio 0.931 (0.913,0.994; p = 0.002)] and shorter cardiopulmonary bypass times [Odds Ratio 0.962 (0.861,0.968; p = 0.02)] during repair were associated with the lowest pulmonary venous gradients and multiphasic flow. Following TAPVR repair with a direct anastomosis, the majority of children can achieve a gradient two times normal or less with multiphasic pulmonary venous flow.

Cardiac-type total anomalous pulmonary venous return is not benign

OBJECTIVE

The objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).

METHODS

This single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.

RESULTS

The connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).

CONCLUSIONS

The number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.

Pyogenic brain abscess associated with an incidental pulmonary arteriovenous malformation

Pulmonary arteriovenous malformations (PAVMs) are rare and often asymptomatic vascular anomalies that can be associated with serious neurological consequences due to right-to-left shunting. We report a case of a woman in her 80s without substantial medical history who presented with a headache, weakness and personality changes, and was found to have a pyogenic brain abscess requiring emergent neurosurgical evacuation. The abscess grew oral flora, suspected to have reached the brain via an incidentally discovered PAVM. With drainage and antibiotics, the patient achieved a full recovery and the PAVM was embolised. To our knowledge, this is the oldest presentation of a PAVM-associated brain abscess in the published literature. Older patients may present without the typical signs and symptoms of a given illness, which complicates accurate diagnosis and treatment. Primary care physicians can help facilitate timely care and positive clinical outcomes.

Surgical correction of partial anomalous left superior pulmonary venous connection to the innominate vein

Partial anomalous pulmonary venous connection is reported to occur in 0.4 to 0.7% of children. Only 3% of these cases involve an anomalous left-sided pulmonary venous connection to the innominate vein [1]. In this video tutorial, we present the technique of reimplantation of the partial anomalous left superior pulmonary venous connection to the left atrial appendage through a median sternotomy and with a cardioplegic heart. We debate the merits of our strategy with respect to our ultimate goal of achieving long-term patency.

Trans-catheter closure of ASD and abnormal connection of left pulmonary vein to vertical vein: A case report

RATIONALE

Partial anomalous pulmonary venous connection is a rare congenital anomaly in which one or more pulmonary veins are connected to the venous circulation leading to left to right heart shunt. Although correction of anomalous pulmonary venous connection is achieved through surgery, there are rare instances where the abnormal pulmonary vein has dual connection to both left atrium and the major systemic veins. Under these circumstances, catheter-based treatment might become a feasible option.

PATIENT CONCERNS

A 22-year-old female presented with exertional dyspnea, holo-systolic murmur in left sternal border, and fixed splitting of S2 in examination.

DIAGNOSIS

The patient was diagnosed with secundum type atrial septal defect (ASD) and dual drainage of left upper pulmonary vein.

INTERVENTIONS

The patient was candidate for device closure. Under TEE guidance, occluder devices were deployed in the upper part of vertical vein and subsequently in place of ASD.

OUTCOMES

Echocardiogram in the next day showed complete occlusion of flow through the vertical vein and ASD. Dual antiplatelet was prescribed on discharge. Follow-up echocardiography after 3 months showed obvious improvement in RV size. Due to suspicion for clot formation, TEE was done and thrombosis with approximate length of extension of 15 mm was detected back to the device. The patient is following for 5 years. Repeated TEE after 2 years did not show any change in the burden of clot.

LESSONS

For comprehensive evaluation of patients with ASD, assessment of pulmonic veins is crucial and in the presence of a vertical vein, the dual drainage of pulmonic veins should be considered.

Recurrent pulmonary arteriovenous malformation in a patient with Sjögren syndrome: A case report

RATIONALE

Pulmonary manifestations of Sjögren syndrome (SS) are variable and may involve the airway or lung parenchyma and increase the risk of vascular and malignant disease. However, to date, only one case of pulmonary arteriovenous malformation (AVM) has been reported in a patient with SS. Here, we report a rare case of recurrent pulmonary AVMs with aggravating multiple cysts in a patient with SS during a period of 14 years.

PATIENT CONCERNS

A 45-year-old woman was diagnosed with SS and pulmonary AVM in the right lung. Her AVMs were embolized successfully and she was followed up annually for 14 years. Eleven years after the initial treatment, her chest computed tomography showed new pulmonary AVMs in the left lung with aggravating multiple cysts.

DIAGNOSIS

We diagnosed her with SS according to the American-European consensus group criteria of 2010. Chest computed tomography and angiographic findings confirmed the recurrence of pulmonary AVMs.

INTERVENTIONS

The patient's recurrent pulmonary AVMs were successfully treated by embolization.

OUTCOMES

Although her multiple cystic lung lesions had been aggravating during 14 years, she received embolization for the pulmonary AVMs twice and developed no complication related to these procedures. Currently, the patient is 56 years old and still alive with good performance state.

LESSONS

To date, only one case of pulmonary AVM has been reported in a patient with SS. The patient died 2.5 years after the diagnosis without recurrence of AVM. Here, we present a rare case of recurrent pulmonary AVMs associated with aggravating multiple cysts in both lungs, which were observed during long-term follow-up, in a patient with SS.