Distal Left Pulmonary Artery Research Articles

Assessment of Pulmonary Arterial Vascular Impedance in Fetuses With Tetralogy of Fallot.

To evaluate the vascular impedance of the pulmonary arteries in fetuses with tetralogy of Fallot (TOF) by Doppler echocardiography. A total of 42 fetuses with TOF (TOF group) and 84 gestational age-matched normal fetuses (control group) were prospectively collected from the Second Xiangya Hospital of Central South University from August 2022 to January 2023. The severity of TOF was classified into mild TOF (z score ≥-2), moderate TOF (-4 < z score < -2), or severe TOF (z score ≤-4) according to the z score value of the pulmonary annulus diameter. The pulsatility index (PI) of the main pulmonary artery (MPA), distal left pulmonary artery (DLPA), and distal right pulmonary artery (DRPA) were measured by pulsed-wave Doppler. The differences in clinical data and echocardiographic parameters between TOF group, control group, and TOF subgroups were compared. Compared with the control group, MPA-PI increased significantly, whereas DLPA-PI and DRPA-PI decreased in TOF group (all P < .001). There were no significant differences in MPA-PI and DRPA-PI among mild TOF, moderate TOF, and severe TOF (all P > .05). However, DLPA-PI decreased significantly in severe TOF compared with mild TOF (P < .05). Fetuses with TOF presented increased vascular impedance in the pulmonary trunk and decreased impedance in distal pulmonary artery branches. Further large and follow-up studies are needed to demonstrate the associations between those changed vascular impedances and the development of PA in patients with TOF.

Pulmonary artery stiffness in fetuses with tetralogy of Fallot.

This study evaluated the elastic characteristics of the pulmonary trunk and distal branches in fetuses diagnosed with tetralogy of Fallot (TOF) using Doppler echocardiography. Data on 42 fetuses diagnosed with TOF and 84 gestational age-matched normal fetuses were prospectively collected from the Second Xiangya Hospital of Central South University between August 2022 and January 2023. The severity of TOF was classified into three categories based on the z-score of the pulmonary annulus diameter: mild (z-score ≥-2), moderate (-4<z-score<-2), and severe (z-score ≤-4). Pulmonary artery stiffness (PAS) in the main pulmonary artery (MPA), distal left pulmonary artery (DLPA), and distal right pulmonary artery (DRPA) was measured using pulsed-wave Doppler imaging. Differences in clinical data and echocardiographic parameters were compared between the TOF group and the normal group, as well as among TOF subgroups. Compared with the normal group, the MPA-PAS in fetuses with TOF was significantly higher, while the DLPA-PAS and DRPA-PAS were notably lower (all P<0.05). The MPA-PAS of fetuses with severe TOF was higher than that of those with mild and moderate TOF (all P<0.05). However, there were no significant differences in the DLPA-PAS or DRPA-PAS among fetuses with mild, moderate, and severe TOF (all P>0.05). Fetuses diagnosed with TOF exhibited increased vascular stiffness in the MPA and reduced stiffness in the distal pulmonary artery (PA). Larger-scale follow-up studies are required to elucidate the relationships between these changes in vascular stiffness and PA development in patients with TOF.

Atypical presentation of renal cell carcinoma: a case report

Our patient was a 61-year-old male who first presented with a diagnosis of renal cell carcinoma and low oxygen saturation at rest. An urgent computed tomography of the thorax revealed a filling defect in the distal left pulmonary artery. We describe our perioperative management of this patient and highlight some challenges in hispostoperative care.

Advances in Hemodynamic Monitoring in Heart Failure Patients

Abnormal hemodynamics are associated with poor clinical outcomes in patients with heart failure. Given the invasiveness and unfeasibility of routine right heart catheterization, non-invasive methodologies to monitor hemodynamics are needed. The CardioMEMS™ device is a recently developed technology that enables remote monitoring of pulmonary artery pressures via an implanted sensor located in the distal left pulmonary artery. Along with the CardioMEMS™, a remote dielectric system might be another promising device that reports indirect intra-thoracic filling pressures associated with pulmonary congestion. In patients with advanced heart failure who require left ventricular assist devices, non-invasive hemodynamic monitoring is particularly necessary, given the increased procedural risks of invasive assessments. The HeartWare ventricular assist device flow waveform is a variable under active investigation that might also provide an estimation of filling pressures. This methodology is expected to lead to the development of a smart pump that can adjust its own settings, including the pump speed, automatically by monitoring the hemodynamics.

Reconstruction surgery case report: ex vivo surgery and auto lung transplantation for pulmonary artery sarcoma

This is a report on the lung autotransplant techniques for the treatment of intimal sarcoma of pulmonary artery (PA). A 58-year-old man was diagnosed with PA sarcoma occluding the right main PA and peripherally extending into the right interlobar PA. First, the tumor was completely removed by pulmonary endarterectomy combined with right pneumonectomy under cardiopulmonary bypass. A following ex vivo evaluation of the explanted right lung revealed that the right lower PA was intraluminally intact, so the right lower lobe was used for reimplantation after being flushed with cold organ preservation solution on a back table. The patient was safely weaned from cardiopulmonary bypass following transplantation. His early post-transplant course was uneventful. He died of tumor recurrence at the distal left PA and liver and bone metastasis 14 months after surgery.

Prenatal diagnosis of absent pulmonary valve syndrome by fetal echocardiography: retrospective analysis of 12 cases

Objective To summarize the echocardiographic features of fetal absent pulmonary valve syndrome (APVS). Methods Clinical data and echocardiograms of 12 cases of fetal APVS prenatally diagnosed in the Department of Pediatric Cardiology, Guangdong Cardiovascular Institute from July 2015 to April 2017 were reviewed retrospectively and the echocardiographic features of APVS were summarized. Results Aneurysmal dilation of the main pulmonary artery and branches arteries were found in all cases, causing tracheal and esophageal compression in one case and lung compression in two cases. Color Doppler revealed systolic and diastolic turbulent blood flow with to-and-fro blood flow in pulmonary arteries and pulmonary regurgitation. All fetuses were situs solitus and atrioventricular concordance. Eleven cases were also identified with malposition of the great arteries accompanied with ventricular septal defect, while the other one with normally related great arteries and intact ventricular septum was diagnosed with dysplasia of distal left pulmonary artery and pericardial effusion. Absent ductus arteriosus, increased cardiothoracic ratio and myocardial hypertrophy were found in four, two and five cases, respectively. Fetal umbilical arterial systolic/diastolic ratio and resistance index of all cases were normal. Conclusions Typical APVS is characterized by absent or rudimentary pulmonary valve accompanied with prominant dilated pulmonary arteries, pulmonary valve stenosis and severe pulmonary regurgitation. It is usually accompanied by conotruncal defects, but attention should also be paid to other atypical cardiac abnormalities during screening. Key words: Pulmonary valve; Congenital abnormalities; Pulmonary valve insufficiency; Echocardiography; Ultrasonography, prenatal

A Serendipitous Identification of a Lead Extraction Complication

A 57-year-old male with a dual chamber pacemaker and symptomatic, persistent atrial fibrillation (AF) accompanying a febrile illness presented for elective transesophageal echocardiography (TEE)-guided cardioversion. The patient was found to have a large 2.5cm×2.3cm, mobile mass attached to the right atrial lead. Following device and lead extraction, he developed progressive shortness of breath which was attributed to his underlying arrhythmia. One month later, AF ablation was pursued and preablation TEE revealed a dilated main pulmonary artery with a 1.8cm×1.6cm mass in the distal left pulmonary artery, which was corroborated by a 1.4cm×2.5cm filling defect in the descending left pulmonary artery on magnetic resonance angiography (MRA). To our knowledge, this is the first case report to document the distal migration of vegetation material into the pulmonary artery with serial TEE and highlights the risk of pulmonary embolism (PE) in patients with large endocardial lead vegetations undergoing transvenous lead extraction.

Chronic effects of pulmonary artery stenosis on hemodynamic and structural development of the lungs

Pulmonary artery (PA) stenosis is a difficult obstructive defect to manage since clinicians cannot know a priori which obstructions to treat and when. Prognosis of PA stenosis and its chronic effects on lung development are poorly understood. This study aimed to characterize the hemodynamic and structural effects of PA stenosis during development. Fourteen male Sprague-Dawley rats underwent left PA (LPA) banding at age 21 days, and 13 underwent sham operation. Hemodynamic and structural impacts were studied longitudinally at 20, 36, 52, 100, and 160 days. Chronic LPA banding resulted in a significant reduction in LPA flow (P < 0.0001) and size of both proximal LPA (P < 0.0001) and distal LPA (P < 0.01), as well as a significant increase in flow and size of the right PA (P < 0.05) throughout development. Flows and sizes adapted such that normal levels of wall shear were restored after banding. At 160 days, LPA banding resulted in a significant decrease in left lung volume and an increase in right lung volume but no significant differences in total lung volume. There was an elevation of proximal LPA pressure as well as right ventricular hypertrophy in the banded animals. The banded lung exhibited arterial disorganization, loss of vessels, and enlargement of its bronchial arteries, whereas the contralateral lung showed signs of vascular pathology. There are consequences on development of both lungs in the presence of an LPA stenosis at young age. These results suggest that early intervention may be necessary to optimize left lung growth and minimize right lung vascular pathology.

Impact of Shunt Type on Growth of Pulmonary Arteries After Norwood Stage I Procedure

The past decade has seen a substantial improvement in the outcome following surgical palliation for hypoplastic left heart syndrome. This has been attributed to modifications in the surgical as well as postoperative management strategies. One such modification is the reemergence of the right ventricle to pulmonary artery (RV-PA) shunt as an alternative to the modified Blalock-Taussig (mBT) shunt as the source of pulmonary blood flow. The RV-PA shunt has been shown to improve the immediate surgical outcome compared with the classic Norwood procedure with an mBT shunt. Despite the several reported advantages, the impact of the RV-PA shunt on growth of the pulmonary arteries and incidence of late development of central PA stenosis remains unclear. This systematic review evaluates the current best available evidence to address this issue and concludes that the evidence from retrospective studies and only available randomized controlled trial (RCT) is conflicting. The retrospective studies predominantly suggest that the Norwood procedure with RV-PA shunt may have favorable effects on the development of the pulmonary arteries due to even distribution of pulmonary blood flow with greater distal left pulmonary artery growth, resulting in more balanced distal branch pulmonary artery size albeit with a greater degree of central pulmonary artery hypoplasia needing surgical attention. On the contrary, the RCT reports that the overall size of the pulmonary artery on angiography before the stage II procedure was smaller in the RV-PA shunt group than in the mBT shunt group, with no information available on incidence of central pulmonary hypoplasia.

Differential branch pulmonary artery growth after the Norwood procedure with right ventricle–pulmonary artery conduit versus modified Blalock–Taussig shunt in hypoplastic left heart syndrome

The Norwood procedure with right ventricle-pulmonary artery conduit is thought to improve postoperative hemodynamics in hypoplastic left heart syndrome, but its effects on pulmonary artery growth are unknown. This study evaluated pulmonary artery growth after the Norwood procedure in patients with a right ventricle-pulmonary artery conduit as compared with patients with a modified Blalock-Taussig shunt. A total of 159 patients at our institution underwent the Norwood procedure between January 2000 and September 2005. Patients were divided into group A or B if they had a modified Blalock-Taussig shunt (n = 103) or a right ventricle-pulmonary artery conduit (n = 56). Angiograms from the pre-Glenn catheterizations were used to measure pulmonary artery size and assess shunt stenosis (n = 64). Fifty-five (53.4%) patients in group A versus 40 (71.4%) in group B underwent Glenn surgery. Group B patients often required an additional shunt (modified Blalock-Taussig) before the Glenn procedure because of hypoxemia (8/40 vs 1/55; P = .004). Branch pulmonary artery growth was better in group B patients who did not require an additional shunt (Nakata index 212 vs 169 mm(2)/m(2); P = .004) and more balanced than in group A (right pulmonary artery/left pulmonary artery ratio = 1.02 vs 1.39; P = .001) as a result of greater left pulmonary artery size (29 vs 19 mm(2); P = .001). However, group B experienced more shunt stenosis (8/32 vs 2/32; P = .001), underwent the Glenn operation earlier (192 vs 246 days; P = .03), and had central pulmonary artery hypoplasia develop more often than group A patients (25/32 vs 14/32; P = .01). The Norwood procedure with a right ventricle-pulmonary artery conduit promotes better distal left pulmonary artery growth resulting in more balanced branch pulmonary artery size, but central pulmonary artery hypoplasia occurs more often. Early right ventricle-pulmonary artery conduit stenosis also increases the need for additional shunting or early Glenn surgery.

Main pulmonary artery translocation for left pulmonary stenosis

Surgical arterioplasty for left pulmonary branch stenosis has often produced unsatisfactory results. We report a new operative technique involving the main pulmonary artery (MPA) translocation technique. This technique provided a wide patency without overstretching. Technique The operation is performed through a median sternotomy. In cases that require an additional aortopulmonary shunt, this procedure is performed through a standard left posterolateral thoracotomy. The left pulmonary artery and MPA are completely dissected to allow anastomosis without overstretching, and the stenotic portion is transected. Next, the MPA is transected and the distal stump is translocated to the distal left pulmonary artery. The anastomosis is completed with a running suture of 7-0 polypropylene. After this anastomosis, a modified Blalock‐Taussig (BT) shunt or a bidirectional Glenn (BDG) shunt is created. Results

Transesophageal Imaging of the Mid to Distal Left Pulmonary Artery in Congenital Heart Disease

We assessed how well transesophageal echocardiography (TEE) images the left pulmonary artery (LPA) in congenital heart disease (CHD). Seventy-nine consecutive patients with CHD were studied. Ideal imaging displayed the mid to distal LPA from the takeoff of the upper lobe artery through the second bifurcation. Imaging quality was graded from 1 (excellent) to 5 (not visualized). Imaging quality was excellent in 8 (10%) patients, good in 25 (32%), fair in 23 (29%), and poor in 12 (15%); the LPA was not visualized in 11 (14%) patients. Imaging grade averaged 2.9 ± 1.2 (SD) and correlated poorly with weight (r = 0.24) but was better in patients without prior operation (grade 2.8 vs 3.3, P <.05). In 2 patients, TEE showed residual stenosis. Thus informative LPA imaging by TEE can be achieved in many patients with CHD and has the potential to change intraoperative or postoperative treatment. (J Am Soc Echocardiogr 1999;12:663-8.)

Percutaneous closure of the small patent ductus arteriosus using occluding spring coils

Objectives. This report summarizes our experience with the use of occluding spring coils to close the small patent ductus arteriosus.Background. Several patent ductus arteriosus occluders (most notably the Rashkind device) have been developed and studied. Occluding spring coils have been used to close abnormal vessels and vascular connections. We previously reported the use of occluding spring coils to close the small patent ductus arteriosus in a small group of patients. This report describes our series of patients having patent ductus arteriosus closure with occluding spring coils.Methods. Between June 1990 and June 1993, 30 patients underwent cardiac catheterization to have patent ductus arteriosus closure by occluding spring coils. Selection criteria were age >6 months and narrowest patent ductus arteriosus internal dimension ⪯3.0 mm by color flow imaging. Definitive selection was based on review of aortograms performed at catheterization. A 5.2F coronary catheter was used to deliver one or two standard occluding spring coils. A loop was delivered in the main pulmonary artery, and the remainder of the coil was delivered across the patent ductus arteriosus and into the aortic diverticulum. Patent ductus arteriosus closure was confirmed by aortography or color flow imaging, or both. Follow-up after coil placement occurred at 6 weeks and 6 months and included two-view chest radiography, echocardiography and color flow imaging.Results. Of the 30 patients, 29 had successful implantation by one (27 patients) or two (2 patients) occluding spring coils. Of these 29 patients, 19 had a clinically apparent and 10 had a silent patent ductus arteriosus. Average ductus minimal internal dimension was 1.7 mm (range 1.0 to 3.0). Complete closure of the ductus was confirmed in 27 patients by aortography or color flow imaging or both (in 24 within 4 h, in 2 after 6 weeks and in 1 after 6 months). Six weeks after implantation, two patients had a tiny residual patent ductus arteriosus noted on color flow imaging. One patient did not have successful implantation. This patient had a 3.2-mm ductus, and two coils migrated to the distal left pulmonary artery and could not be retrieved. There were no deaths or any significant complications noted during early or late follow-up in these patients.Conclusions. Occluding spring coils may have additional application in closing the small patent ductus arteriosus.

Pulmonary artery configuration after palliative operations for hypoplastic left heart syndrome

Pulmonary artery architecture and symmetry after palliative operations for hypoplastic left heart syndrome may affect subsequent suitability for a modified Fontan operation. Two-dimensional echocardiography was used to measure pulmonary artery diameter and assess symmetry after two types of systemic-pulmonary artery shunts: modified right Blalock-Taussig shunt (14 patients) and central shunt (from underside of aortic arch gusset to pulmonary artery confluence) (14 patients). Age, weight, preoperative diameter of right and left pulmonary arteries (proximal, middle, and distal segments), and mean interval between preoperative and postoperative echocardiographic studies (20.2 +/- 4.4 days in the Blalock shunt group; 19.1 +/- 6.8 days in the central shunt group) were similar. Early postoperatively, patients with a Blalock shunt showed a significant decrease in the diameter of all pulmonary artery segments except the distal right pulmonary artery. The diameters tapered from distal right to distal left pulmonary artery in this group. Patients with the central shunt had a significant decrease in the diameter of all pulmonary artery segments. There were no significant differences when cross comparisons were made of the various pulmonary arterial segments in patients after a central shunt. Similar findings persisted in 19 patients from both groups who had a late postoperative echocardiogram (mean interval between studies = 271 days in the group of 10 patients with Blalock shunt and 167 days in the group of nine patients with a central shunt). In conclusion, the central shunt preserves pulmonary artery symmetry, which may be important in candidates for the Fontan operation in infancy.

Catheter Recording of Left Atrial Activation from Left Pulmonary Artery in the Wolff‐Parkinson‐White Syndrome: Validation of the Technique with Intraoperative Mapping Results

Accurate localization of accessory pathways (AP) in the Wolff-Parkinson-White (WPW) syndrome requires detailed atrial mapping. Coronary sinus catheterization is so far the most accurate method of left atrial mapping, but it can be technically difficult in some patients. We evaluated the feasibility of left atrial mapping from the left pulmonary artery in 24 patients with WPW syndrome. All patients except one underwent surgical cryoablation of their AP and the results of intraoperative mapping are available for comparison. Mapping in sinus rhythm showed recording of atrial activity in the distal left pulmonary artery occurred 56 +/- 20 ms after activation of high right atrium and 24 +/- 4 ms after activation in the His bundle area, but coincident with left atrial activation in the distal coronary sinus (56 +/- 20 and 53 +/- 13, respectively). Mapping during ventricular pacing or orthodromic tachycardia could differentiate patients as having a right sided, left sided or paraseptal first site of activation. Eleven patients had a left lateral AP, four had a left posterior AP, five had left posteroseptal AP and one had a left anterior AP. The remaining three patients had a right sided AP. Intraoperative results correlated with pre-operative findings in 22 out of 23 (95%) patients who underwent surgical ablation of AP. Thus, recordings form the left pulmonary artery reflect left atrial activity and may be of aid in localizing an AP, especially when coronary sinus recordings cannot be obtained. This technique, however, should not replace the more accurate method of coronary sinus mapping.

Illusions leading to surgical closure of the distal left pulmonary artery instead of the ductus arteriosus: R. G. Pontius, G. K. Danielson, J. A. Noonan, and J. P. Judson. J Thorac Cardiovasc Surg 82:107–113, 1981

Illusions leading to surgical closure of the distal left pulmonary artery instead of the ductus arteriosus: R. G. Pontius, G. K. Danielson, J. A. Noonan, and J. P. Judson. J Thorac Cardiovasc Surg 82:107–113, 1981

Illusions leading to surgical closure of the distal left pulmonary artery instead of the ductus arteriosus

Illusions, in a collected series of 10 cases, have led to the surgical closure of the distal left pulmonary artery instead of the patent ductus. When the rare, anatomically atypical patent ductus arises from the arch proximal to the subclavian artery, the recurrent laryngeal nerve is found passing under the arch instead of under the ductus. A large ductus creating the illusion of the arch, with the nerve beneath it, can lead to the impression of an anatomically atypical ductus with the resultant surgical closure of the distal left pulmonary in lieu of the ductus. For over two decades the problem has been a recurring one which deserves recognition among the better known complications of ductus operations.

Surgical correction of absence of proximal segment of left pulmonary artery.

In a 14-month-old patient who had been repeatedly hospitalized for recurrent pulmonary infections, cardiac angiography found "absence" of the left pulmonary artery, but thoracic aortography demonstrated that a rudimentary patent ductus filled a distal patent pulmonary artery. There was a coexistent vascular ring with a retroesophageal right subclavian artery. At surgical exploration it was possible to mobilize the distal left pulmonary artery and perform a direct anastomosis between the left pulmonary artery and the main pulmonary artery. This is perhaps the first patient in whom such an operation has been performed. It is emphasized that the absence of a pulmonary artery on pulmonary angiography does not indicate that the entire pulmonary artery is absent. The presence of a patent and surgically reconstructable distal pulmonary artery can be determined only by aortography or possibly by surgical exploration.