Left Main Pulmonary Artery Research Articles

Compression of the left main bronchus and pulmonary artery after entire aortic replacement with Dacron arterial grafts

Compression of the left main bronchus and pulmonary artery after entire aortic replacement with Dacron arterial grafts

New technique of right heart bypass in congenital heart surgery with autologous lung as oxygenator

Background Modifications have been made in cardiopulmonary circuit to reduce the inflammatory deleterious effects and cost. We present our experience of one such right heart bypass (RHB) circuit utilizing autologus lung as oxygenator. Methods From September 2001 to December 2002, 15 patients underwent congenital heart surgery with this technique. Bypass circuit consisted of a reservoir and a roller pump along with a cardiotomy sucker. The left pulmonary artery and main pulmonary artery were used for arterial return, and venous drainage was achieved with innominate vein cannulation. Inferior vena cava cannulation was performed when needed. Thirteen patients underwent bidirectional Glenn shunt surgery (12 to 24 months, 6 to 10 kg). One patient (26 years old) underwent central shunt with enlargement of confluence and left pulmonary artery. Another patient (18 months old) underwent 1.5 ventricle repair. Results There were no hospital deaths. Mean flow achieved on RHB was 0.57 ± 0.3 L/min/m 2, central venous pressure was 3.3 ± 1.8 mm Hg (0 to 7 mm Hg), and mean arterial pressure could be maintained satisfactorily in all patients (54 ± 14 mm Hg). Mean RHB time was 54 ± 14 min. Mean central venous pressure was 10.1 ± 2.4 mm Hg after procedure and saturation was similar to that on (RHB 88% ± 8%). The mean amount of drainage was 9.1 ± 4.2 mL/kg per 24 hours. Avoiding an oxygenator and reducing the number of tubings achieved a combined cost savings of 40% for all procedures. Conclusions Right heart bypass is a simple, safer, and less expensive alternative to conventional cardiopulmonary bypass. This technique allows effective decompression of superior vena cava, adequate oxygenation, and predicts saturation after Glenn shunt. It can also be applied for central shunts and pulmonary artery reconstructions with cost containment.

The technique of unilateral double lobar lung transplantation in a canine model

Objective Bilateral living-donor lobar lung transplantation has become an accepted alternative to cadaveric lung transplantation. Because only one lobe is implanted in each chest cavity, this procedure seems to be best suited for children and small adults. The purpose of this study was to develop a technique of unilateral double lobar lung transplantation that can be applied to large adult patients. Methods Unilateral double lobar lung transplantation was performed in 6 weight-matched pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the right hemithorax after right pneumonectomy. The left graft was implanted as a right upper lobe, having been rotated 180° along the vertical axis and then 180° along the horizontal axis. The right graft was implanted in the natural anatomic position. Function of the transplanted grafts was assessed for 3 hours after ligation of the left main pulmonary artery while the animals were ventilated with 100% oxygen. Results Morphologic adaptation of the 2 grafts in the right hemithorax was found to be excellent. All 6 animals survived the assessment period with excellent pulmonary function. At the end of the 3-hour assessment period, the arterial oxygen tension was 519 ± 31 mm Hg, and the mean pulmonary artery pressure was 30.5 ± 1.7 mm Hg. Conclusions Unilateral double lobar lung transplantation was technically possible and associated with satisfactory early pulmonary function in a canine experimental model.

Unusual cause of dyspnea after pneumonectomy

The patient was readmitted to the hospital 2 weeks after surgery because of increasing shortness of breath. He had not experienced paroxysmal nocturnal dyspnea, orthopnea, angina, or symptoms of acute cardiac decompensation. The patient’s oxygen saturation was 90% while breathing room air, his pulse was regular at 80 beats/min, and his blood pressure was 130/70 mmHg. There were no signs of heart failure. The trachea was central to the suprasternal notch on palpation. Chest examination revealed dullness to percussion and auscultation on the left side and good aeration on the right side. An electrocardiogram revealed no changes in a right bundlebranch block that was seen preoperatively. Levels of cardiac enzymes (troponin-I and creatine kinase-MB) were normal. Computed tomography and computed tomography angiography of the chest showed no evidence of pulmonary embolism or pulmonary infection. Positive findings included a small rightsided pleural effusion, mild emphysematous changes in the right lung, and near-complete filling with fluid of the pleural space within the left hemithorax. A portable chest radiograph was also obtained, and the image is shown in Fig 1. What was the diagnosis?

Propofol Attenuates Prostacyclin-induced Pulmonary Vasorelaxation in U46619 Preconstricted Dog

Background: The goal of our study was to investigate the effects of propofol anesthesia on the pulmonary vascular response to prostacyclin during U46619 precontraction in dogs. Methods: Eight mongrel dogs were anesthetized and instrumented to measure the left pulmonary vascular pressure-flow relation, by loosely positioning a hydraulic occluder around the right main pulmonary artery and placing an electromagnetic flow probe around the left main pulmonary artery. During slowly occlusion of the right main pulmonary artery, the pressure-flow plots were measured in the left main pulmonary artery in the control and propofol-anesthetized (5.0 mg/kg plus 0.5 mg/kg/min intravenously) states at baseline, after preconstriction with the U46619, and during the cumulative intravenous administration of prostacyclin. Results: Propofol had no effect on the baseline pressure-flow relation versus the control state. A lower (P

A Case of Unilateral Absence of Left Pulmonary Artery Presenting Hemoptysis

Unilateral absence of a pulmonary artery (UAPA) is a rare congenital anomaly that is frequently associated with other cardiovascular anomalies first reported by Fraentzel in 1968. Most patients who have no associated cardiac anomalies have only minor or absent symptoms. We experienced a case of isolated UAPA in a young female presenting hemoptysis. The chest radiograph showed a small left lung volume and high resolutional CT of chest showed multiple subpleural nodules and centrilobular nodules in parenchyma. The video-assisted thoracoscopic biopsy revealed diffuse dilated vessels in visceral pleura. The pulmonary angiogram confirmed the absence of the left main pulmonary artery.

Bronchoplastic procedures and pulmonary artery reconstruction in the treatment of stage III lung cancer invading pulmonary artery

To summarize the clinical results of bronchoplastic procedures and pulmonary artery reconstruction or combined with other resection and plasty of heart, great vessels in the treatment of 304 patients with locally advanced lung cancer. From February, 1983 to December, 2001, double sleeve resection and reconstruction of bronchus and pulmonary artery, or combined with other resection of heart, great vessels were carried out in 304 patients with locally advanced lung cancer. The operations included double sleeve left upper lobectomy in 199 cases; double sleeve right upper lobectomy in 21 cases; double sleeve right upper middle lobectomy in 14 cases; double sleeve left upper lobectomy combined with resection of left atrium in 8 cases; double sleeve right upper lobectomy combined with superior vena cava (SVC) resection and reconstruction with Gortex graft in 29 cases; double sleeve right upper middle lobectomy combined with SVC resection and reconstruction in 21 cases; double sleeve right upper middle lobectomy, carinal and SVC resection and reconstruction in 11 cases; left pneumonectomy combined right main pulmonary artery and pulmonary artery trunk resection and reconstruction with Gortex graft in 1 case. There were 3 operative deaths. The operative mortality was 1% in this series. Sixty four patients had operative complications. The operative complication rate was 21.05% (64/304). The 1-, 3-, 5- and 10 year survival rates were 81.75%, 60.14%, 37.21% and 24.39% respectively. Double sleeve lobectomy or comblined with other resection and reconstruction of heart, great vessels can significantly improve the prognosis and increase the curative rate and long term survival in patients with locally advanced lung cancer.

Left Atrial Wall Calcification after Mitral Valve Replacement: CT Findings and Clinical Significance

Purpose: To evaluate the CT findings and clinical significance of left atrial wall calcification in patients who had undergone mitral valve replacement. Materials and Methods: The unenhanced chest CT scans of 36 consecutive patients who had undergone mitral valve replacement were retrospectively reviewed, and left atrial calcification was found in 15. To determine the clinical significance of this, the CT findings were assessed in terms of the diameter of the left main pulmonary artery, the interval between previous surgery and scanning, and pulmonary arterial pressure. Results: Left atrial wall calcification was either focal (linear, n=7; nodular, n=5), or diffuse (involving at least one-fourth of the left atrial wall) (n=3), and associated left atrial thrombus was found in two patients. Systolic pulmonary arterial pressure was significantly higher in those with calcification than those without (p

QUANTITATIVE ANALYSIS OF ENDOTHELIN AND NITRIC OXIDE SYNTHASE IN RAT MODEL OF POSTOBSTRUCTIVE PULMONARY VASCULOPATHY

There is increasing evidence that endothelin (ET) and endothelial nitric oxide synthase (eNOS) may contribute various kinds of pulmonary vascular remodeling, including postobstructive pulmonary vasculopathy (POPV), which resulted from chronic ligation of unilateral pulmonary artery. The aim of this study was to investigate the expression of ET-1, ET-A receptor, ET-B receptor, and eNOS quantitatively in POPV rats. One month after a left thoracotomy with either left main pulmonary artery ligation (ligated group) or no ligation (control group), rat pulmonary arteries and lungs were used for Western blot analysis using specific antibodies against ET-1, ET-A receptor, ET-B receptor, and eNOS. ET-A receptor was more highly expressed in the pulmonary arteries of ligated rats compared to the control. The expression of ET-1, ET-B receptor,and eNOS was not different between ligated and control rats. These findings suggest that ET-A receptor overexpression would play a main role for pulmonary arterial remodeling in POPV rats, whereas eNOS may serve as a compensatory mediator.

Experimental Use of an Illuminated and Magnetic Tip, Flow-Directed Pulmonary Artery Catheter for Lung Resection

The authors performed a study to design and evaluate a device giving the surgeon added protection against pulmonary artery injury in a closed thoracic compartment. Eleven swine were used for a total of 12 lobectomies. A light-bearing, magnetic-tipped, modified Swan-Ganz catheter was passed through the jugular vein into the left pulmonary artery. By using magnetic guidance through a port site and balloon inflation, cessation of flow in the pulmonary artery was documented by Doppler. Twelve video-assisted lobectomies were performed. Nine of 12 (75%) lobectomies were completed successfully by using the magnetic-tipped, illuminated balloon catheter. In 4 cases, the catheter displaced because of the short left main pulmonary artery in swine. In one case, the balloon was recovered, and successful lobectomy was performed. The use of a magnetic-tipped, flow-directed device may provide an effective means of endovascular control during thoracoscopic pulmonary arterial dissection.

A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase‐antineutrophil cytoplasmic autoantibodies

A 53-year-old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X-ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium-macroaggregated albumin (99mTc-MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)-antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non-specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO-ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO-ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO-ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.

Experimental lung transplantation using non-penetrating vascular clips for anastomosis of the pulmonary artery.

Reliable and rapid anastomosis is critical in lung transplantation. The purpose of this study is to show the appropriateness of sutureless anastomosis of the pulmonary artery using a nonpenetrating vascular clipping device. The left lung was excised and the cranial lobe was transplanted autologously in 9 dogs. The anastomosis of the left main pulmonary artery (PA) (1 cm) was performed using a vascular clipping system. PA anastomosis was performed in 7 dogs in 8 to 13 minutes. The endovascular surface of the anastomotic site was smooth, and passage of silicone rubber through the anastomosis was good 14 or 28 days after surgery. Microscopic examination of the anastomotic sites showed excellent healing without evidence of intimal hyperplasia. The vascular clipping system facilitates anastomosis of the PA in lung transplant surgery.

PULMONARY VASCULAR REMODELING DISTAL TO PULMONARY ARTERY LIGATION IS ACCOMPANIED BY UPREGULATION OF ENDOTHELIN RECEPTORS AND NITRIC OXIDE SYNTHASE

There is increasing evidence that the pathogenesis and progression of many forms of pulmonary vasculopathy are related to abnormalities in endothelial mediators, including endothelin-1 (ET-1) and nitric oxide (NO). Using a rat model of chronic unilateral pulmonary artery ligation, we investigated the role of ET-1 and NO in postobstructive pulmonary vasculopathy (POPV). Eight months after a left thoracotomy with either left main pulmonary artery ligation (ligated group) or no ligation (sham group), rat lungs, including those contralateral to the ligation (hyperperfused group), were fixed and mounted for histologic sectioning. Morphometric measurements were carried out by computer-assisted image analysis and immunohistochemical staining was performed using specific antibodies against ET-1, ETA, and EBB receptors, and endothelial NO synthase (eNOS). Compared to sham lungs, the ligated lungs showed (1) an increase in muscular, adventitial, and intimal thickness of pulmonary artery; (2) increase in external diameter of the bronchial artery (39.8+/-2.2 mum vs.16.8+/-0.9 mum in sham group; P <. 005) and number of bronchial arteries per bronchiole (3.21+/-mu0.26vs.1.86+/-mu0.21 in sham group; P <. 001); and (3) increase in the intensity of eNOS and ETA, B receptor immunoreactivity. No morphometric or immunohistochemical differences were observed between the hyperperfused and sham lungs. These ndings suggest that increased synthesis of endothelial NO may serve as a compensatory mediator in ET-1 mediated vascular remodeling.

Altered reactivity of pulmonary vessels in postobstructive pulmonary vasculopathy.

Chronic ligation of one pulmonary artery results in pulmonary vascular remodeling and bronchial angiogenesis, collectively known as postobstructive pulmonary vasculopathy (POPV). To investigate pulmonary vascular reactivity in POPV, we ligated the left main pulmonary artery of guinea pigs and, after 1-10 mo, prepared explants by inflating lungs with agarose and sectioning them into approximately 1-mm-thick slices; we measured areas of pulmonary vessels and determined contractile responses to histamine and serotonin (5-HT) and relaxant responses to ACh and sodium nitroprusside. We found maximal contractions of arteries to 5-HT (24. 4 +/- 2.6%) and of veins to histamine (53.9 +/- 4.7%) were significantly increased in POPV of 3-mo duration compared with those of controls (16.8 +/- 1.5 and 40.8 +/- 5.0%, respectively). Relaxation of arteries with ACh was enhanced at 10 mo but not at 1 mo after ligation. Relaxation with sodium nitroprusside was increased in veins at 1 mo after ligation but was not altered in arteries. Morphometry revealed reduced diameters of arteries and veins without increased medial thickness. Our data suggest that the enhanced contractile responses of pulmonary vessels to histamine and 5-HT in POPV were not a result of endothelial dysfunction or of structural alterations but might be caused by as-yet-undiscovered mechanisms.

Non-surgical management of a perforated left anterior descending coronary artery following cardiopulmonary resuscitation

A 49 year old male developed cardiocirculatory arrest following laparoscopic surgery of an inguinal hernia. Cardiopulmonary resuscitation (CPR) was started. The primary ECG showed ventricular fibrillation, after defibrillation a tachyarrhythmia and a newly developed right bundle branch block were documented. In addition, ST-elevations were seen in the left precordial leads. After 20 min of CPR the circulation was reestablished with high doses of catecholamines. Transthoracic echocardiography demonstrated a 7 mm pericardial effusion with mild impression of the right ventricular free wall. The patient underwent urgent heart catheterization for suspected pulmonary embolism (differential diagnosis: acute myocardial infarction). Pulmonary angiography demonstrated floating thrombi in the left main pulmonary artery, which could be fragmented using a pigtail catheter. Pulmonary angiography was followed by coronary angiography, which demonstrated a sharply interrupted left anterior descending artery (LAD), while the coronary arteries in general were found to be regular. The history, the morphology of the LAD-interruption, the concomitant pericardial effusion and the sternal and rib fractures were consistent with a type III coronary perforation in the classification of Sutton and Ellis. As contrast medium penetration into the pericardial space persisted after recanalization of the LAD, a 19 mm stent graft (Jostent) was used for closure. These grafts are constructed using a sandwich technique with an ultrathin layer of expandable polytetrafluorethylene being placed between two stents. After implantation of the stent graft no more contrast medium penetration was documented. Coronary perforations following blunt chest trauma is a rare complication, which has been described only once following CPR (2). Stent grafts can be used safely for acute closure of such perforations.

Massive Intraoperative Pulmonary Embolism Coincident with the Administration of Succinylcholine

Massive Intraoperative Pulmonary Embolism Coincident with the Administration of Succinylcholine

Increased Reactivity to Endothelin of Pulmonary Arteries in Long-term Post-obstructive Pulmonary Vasculopathy in Rats

Post-obstructive pulmonary vasculopathy (POPV) describes the constellation of findings following chronic ligation of one pulmonary artery, including bronchial angiogenesis, pulmonary vasculopathy and increased vasoreactivity to pharmacologic agents. Previously, we found in rats with POPV of 28 days duration that maximal responses to endothelin-1 (ET-1) and ET-3 of pulmonary arteries but not veins were increased, and that relaxation of arteries to ET-1 was reduced, attributable to an elevated proportion of ETAover ETBreceptors. To determine the reactivity of pulmonary vessels and airways to ET in protracted POPV, we ligated the left main pulmonary artery of nine rats. Eleven months later, using a lung explant technique, we compared contractile responses of pulmonary vessels and airways to ET-1 and ET-3 in POPV lungs with controls. Morphometric measurements were made on the vessels, and immunoreactivity to ET-1 and endothelin converting enzyme (ECE-1) studied. We found contractile responses to ET-1 and ET-3 significantly increased in arteries, but not veins or airways. Morphometry showed arteries and veins had reduced diameters with muscle thickening only in veins. Expression of ET-1 and ET-3 in vascular endothelial cells and airway epithelial cells were not altered significantly. Our data suggest that protracted POPV selectively enhanced the contractility of pulmonary arteries to ET, and is not attributable to medial muscle thickening.

Pulmonary leiomyosarcoma extending into left atrium or pulmonary trunk: complete resection with cardiopulmonary bypass

Primary pulmonary leiomyosarcoma is a rare tumor. Few cases have been treated surgically because of its rapid invasion into the pulmonary trunk or heart and tendency toward massive intrapulmonary metastases. We report the cases of two patients with leiomyosarcoma originating in a pulmonary artery or vein that involved the pulmonary trunk or left atrium, both of whom underwent complete surgical resection with cardiopulmonary bypass (CPB). Since their operations, these patients have shown no evidence of recurrent tumor. PATIENT 1. A 72-year-old woman with persistent cough, chest pain, and hemoptysis was referred to our hospital for evaluation and treatment of presumed pulmonary thromboembolism. An angiogram revealed filling defects in the pulmonary trunk, absence of filling of the left main pulmonary artery, and decreased arterial filling in the left lung. A biopsy specimen was obtained from a tumor in the left main pulmonary artery by means of a suction catheter, and the pathologic diagnosis of sarcoma was made. Computed tomography disclosed a mass occluding the left main pulmonary artery and densely filling pulmonary artery branches. Median sternotomy was performed and CPB was applied. The left pulmonary veins were ligated and the left main pulmonary artery was incised. A large tumor completely filled the left main pulmonary artery. Extension of the incision into the pulmonary trunk disclosed that the tumor invaded its wall laterally on the left. The portion of tumor located in the left main pulmonary artery and pulmonary trunk, including the left main pulmonary artery and the left lateral wall of the trunk, was excised. Direct suture closure of the pulmonary trunk was carried out and CPB was terminated. The left main bronchus was transected and left pneumonectomy was completed. Fig. 1 shows the resected left lung and pulmonary artery. Tumor in the main pulmonary artery extended intraluminally into its branches. The tumor was diagnosed histologically with the aid of immunohistochemical stainFrom the Department of Thoracic and Cardiovascular Surgery, Mie University, School of Medicine, Tsu, Japan.

Nonneoplastic diseases of aorta and pulmonary trunk--Part V.

This five-part review focuses on selected nonneoplastic diseases of the aorta and pulmonary trunk. Because many more diseases affect the aorta compared with the pulmonary trunk and the right and left main pulmonary arteries, most of this review will be devoted to disorders of the aorta. Part V of this five-part series on diseases of the aorta and the pulmonary trunk focuses on nonneoplastic diseases of the pulmonary trunk and the right and left main pulmonary arteries.

Endothelin reactivity and receptor profile of pulmonary vessels in postobstructive pulmonary vasculopathy

Chronic ligation of one pulmonary artery results in pulmonary vascular remodeling and bronchial angiogenesis, collectively known as postobstructive pulmonary vasculopathy (POPV). To determine whether the reactivity of pulmonary vessels to endothelins (ET) was altered in POPV and to explore potential mechanisms, we ligated the left main pulmonary artery of 18 rats. Four weeks later, using a lung explant technique, we compared POPV lungs with controls for contractile responses of intrapulmonary vessels to ET-1 and ET-3 and for relaxant responses to ET-1 and sodium nitroprusside (SNP) after precontraction with U-46619. Morphometric measurements were made on vessels studied pharmacologically. Competition receptor binding studies with 125I-labeled ET-1 and unlabeled ET-1 and BQ-123 were performed using membrane proteins of pulmonary vessels. We found, in arteries, that contractile responses to ET-1 and ET-3 were significantly increased and that relaxant responses to ET-1 but not to SNP were reduced; in veins, only relaxation to SNP was increased. Morphometry showed that arteries and veins in POPV had reduced diameters without altered muscle thickness. Receptor binding studies showed that the proportion of ETA receptors in arteries was significantly increased in POPV (66%) vs. controls (54%). We conclude that, in POPV, the increase in reactivity to ET-1 and ET-3 is primarily related to an augmented proportion of ETA receptors.