Pulmonary Artery Aneurysm: Analysis, Diagnosis, and Treatment in Five Chinese Patients

Case Report

Pulmonary Artery Aneurysm: Analysis, Diagnosis, and Treatment in Five Chinese Patients

Corresponding author: Shanmukha Sasank Boggavarapu, Department of Cardiovascular Surgery, The First Affiliated Hospital of Zhengzhou University, No: 1 Jian Sha East road Zhengzhou, Henan, PR China – 450000; Email: 991812866@qq.com

Abstract

Pulmonary artery aneurysms (PAA) are very rare entities that are associated with anatomical, pathological and physiological anomalies of cardiovascular diseases. This study is to improve the understanding of the disease, the level of diagnosis and surgical treatment in patients with pulmonary artery aneurysm.

Methods: The clinical data of 5 patients with PAA were admitted in The First Affiliated Hospital of Zhengzhou University from December 2005 to June 2015 were retrospectively analyzed. The group including 4 females and 1 male, with an average age of 41±7.5 years (23- 60 years old), 3 patients with congenital heart disease, 1 with pulmonary stenosis, and 1 with a history of pre-infection, all patients underwent surgical correction.

Results: In this group of 5 patients, 1 patient died after the operation and 4 patients were cured. The follow-up time of 4 patients was 8years, 5years, 3 years and 1 year (follow-up order since the first case), with improved heart function of grade I-II (NYHA). The recovery was normal and 4patients returned to normal life.

Conclusion: The incidence of the pulmonary aneurysm is low, clinically rare, and there are many clinically specific symptoms. Early detection is more difficult. After diagnosis, the condition should be comprehensively evaluated, and appropriate surgical methods should be selected to actively correct the aneurysm to avoid rupture of the tumor.

Keywords: Pulmonary artery; Aneurysm; Congenital heart disease

The PAA is an abnormal expansion of the pulmonary artery, with a very low incidence of only 0.073%. Priviteri reported a ratio of approximately 1:250 to the incidence of aortic aneurysm [1]. The upper normal limit for the diameter of the main PA on CT is 29 mm and that of the right interlobar artery is 17 mm [2,3]. A PAA that exceeds this dimension can be considered enlarged, and one that exceeds 40 mm can be considered aneurismal According to this standard, if the diameter of the main pulmonary artery exceeds 45 mm, the diameter of the left and right pulmonary artery exceeds 30 mm, and the aneurysm can be diagnosed.

Pulmonary artery aneurysm is a rare pathological condition, the management of which is not clearly established [4–8], commonly dyspnea, cough, hemoptysis, chest pain, and other symptoms, combined with a pulmonary arteriovenous shunt, cyanosis, combined with thrombosis can cause emboli Symptoms of central nervous system disease. At present, there is no clear guide to the diagnosis and treatment of pulmonary aneurysms, and conservative treatment is usually the first choice, and surgery has achieved good results. Commonly used methods include pulmonary artery reconstruction or replacing with a dacron graft either surgically or interventional deploying a stent. Domestic reports in this area are mainly based on case studies done in The First Affiliated Hospital of Zhengzhou University from December 2005 to June 2015, a total of 5 patients with pulmonary artery aneurysm were treated surgically. The clinical data of 5 patients with pulmonary artery aneurysm were retrospectively analyzed, and the experience of diagnosis and treatment was summarized in the literature to enhance the pair. The understanding of the disease and the improvement of the level of diagnosis and treatment are reported below.

Case presentations

Case -1

A 30 years old female, due to fatigue and dyspnea for half a year who had a sudden chest pain with syncope admitted for 2 days in an emergency. With the cardiac echocardiogram, CT, DR and other related examination she is clinical diagnosis as congenital heart disease with ventricular septum defect (VSD), severe pulmonary hypertension, pulmonary artery aneurysm, pulmonary valve insufficiency, tricuspid regurgitation.

The Patient underwent surgery for ventricular septum defect repair + pulmonary artery replacement + pulmonary valve dilation + tricuspid valvuloplasty (TVP).

A standard median sternotomy was performed and the patient was placed on cardiopulmonary bypass (CPB). The cross-clamp time was 64minutes and the lowest core temperature was 28°C. During the operation, the patient’s aorta was measured about 40mm in diameter and the diameter of the pulmonary artery was about 65mm. The Pulmonary artery aneurysm was resected and the right and left pulmonary artery were mobilized. The VSD was closed using a bovine pericardium and then DeVega annuloplasty was performed to repair the tricuspid valve.  A triple commissurotomy was carried out and the pulmonary valve was then tested with a 25 mm diameter Hegar probe. The pulmonary trunk was then resected 1cm above the commissures and a 32 mm Dacron tube was implanted with a 4-0 Prolene running suture. The left pulmonary branch was then sectioned a few millimeters below the origin of the lobar branches and the distal extremity of the tube was sutured on the distal stump. The right pulmonary artery branch was finally reimplanted on the right lateral face of the Dacron tube with a terminal-lateral 5-0 Prolene running suture. Then the patient was weaned from CPB without inotropic support. The postoperative course was completely uneventful and the patient was extubated on the same operative day. The ICU stay was 48hours, the patient was discharged on the tenth postoperative day and there were no adverse events or complications 3month and 6-month follow-up. The latest follow up was 8 years after surgery.

Case-2

A 46 years old male admitted in the hospital due to dyspnea for 4 months. Cardiac echo, CT (Figure 1&2) and other related examinations were clinically diagnosed as congenital heart disease with a ventricular septum defect and moderate to severe pulmonary hypertension that led to pulmonary artery dilation.

The patient underwent ventricular septum defect repair + pulmonary artery reconstruction. The tumor was seen to be approximately 63 mm × 113 mm.

A median sternotomy was performed and the patient was placed on the bypass machine. The aneurysm was so huge that the 80% of intra-operative space was occupied. The pulmonary artery aneurysm was resected by removing the significant amount of the anterior portion of the arteries by a longitudinal incision down to the main pulmonary artery into the left pulmonary artery.  VSD is closed primarily and then pulmonary artery is replaced with a Dacron graft and cover with the pre-existing pulmonary artery. After the operation, he was sent to the intensive care unit. 6 hours after surgery the vital signs were stable and then he was extubated, and he was transferred back to the general ward on the 2nd day of surgery and discharged after 8days.

Figure-1 and 2:  Case-2 Patient CT

Case- 3

23 years old female patient visited the hospital due to chest pain, fever for 1-month. She was immediately admitted and she went through the ultrasound and pulmonary artery CTA (Figure 3) examination but her ECG was normal. She was clinically diagnosed with pulmonary artery aneurysm, pulmonary valve insufficiency, and right ventricular hypertrophy.

Through a median sternotomy, a giant aneurysm involving both the pulmonary trunk and the left pulmonary artery was seen clearly after exposing the pericardium. The patient was placed on hypothermic cardiopulmonary bypass with cannulation of the ascending aorta (AA) and superior and inferior vena cava, followed by aortic cross-clamping and cardiac arrest with cold blood cardioplegia. A longitudinal incision was made on the anterior wall of the pulmonary trunk. The stenotic pulmonary valve with the fusion of all three commissures was detected through the incision. Valvuloplasty was performed by cutting through the commissures until the annulus was reached. Approximately 1 cm of the artery wall at each end of the incision was excised. Then, the pulmonary trunk was closed with a 4-0 prolene running suture and tested with a 26 mm diameter probe. Cardiopulmonary bypass and aortic cross-clamping times were 68 and 39 min, respectively. The patient was extubated on the following day and recovered uneventfully. The postoperative CT scan showed a near-normal pulmonary trunk and a significantly reduced left pulmonary artery (Figure 4). TTE revealed a competent pulmonary valve without notable regurgitation, as well as markedly improved LVEF (58%). Pathological examination of the resected artery wall revealed myxoid degeneration, loss of endothelial cells and fragmentation of elastic fibers in the tunica media. The patient was discharged on the 10th day without any complaints and was followed up periodically. She continued to be well up to the present day.

Figure-3 and 4: Pulmonary artery CTA pre and post surgery

Case-4

A 52 years old female patient admitted in the hospital with symptoms of chest pain for 1 year. Ultrasound report shows dilated pulmonary artery and severe pulmonary hypertension, tricuspid regurgitation. CTA confirms the pulmonary artery aneurysm along with pulmonary stenosis. This patient went under surgical repair.

A standard median sternotomy was performed and the patient was placed on CPB. The cross-clamp time was 52 minutes and the lowest core temperature was 30 °C. During the operation, the patient’s large aneurysm was seen through the pericardium and was seen clearly after the opening the pericardium and the diameter of the pulmonary artery were about 6cm. The Pulmonary artery aneurysm was resected and the right and left pulmonary artery were mobilized. A triple commissurotomy was carried out and the pulmonary valve was then tested with a 32 mm diameter Hegar probe. The pulmonary trunk was then resected 1cm above the commissures and a 28 mm Dacron tube was implanted with a 4-0 Prolene continuous running suture with an end to end anastomosis in the proximal and distal ends. Tricuspid valve was repaired with a De Vega annuloplasty prior to the closure pulmonary artery. Post surgery the patient was shifted to ICU. The patient died on the second day because of disseminated intravascular coagulation (DIC) and secondary acute respiratory distress syndrome (ARDS).

Case-5

A 60 years old female, admitted in hospital with symptoms of chest tightness for 2 weeks after the tests by trans-thoracic ultrasound, CT and trans-esophageal ultrasound we found pulmonary artery aneurysm with a large atrial septum defect (ASD) and severe pulmonary hypertension.

The standard median sternotomy was performed and the patient was placed on CPB. The PAA was resected by removing the significant amount of the anterior portion of the arteries by a longitudinal incision down to the main pulmonary artery on to the right pulmonary artery. The incision was just above the level of bifurcation. The longitudinal incision was closed primarily with running sutures. ASD was closed before closure of the pulmonary artery. Then the patient was shifted to ICU ward extubated on the second day of surgery. Later then transferred to the general ward. This patient discharged on the 13th postoperative day.

Results

In this group of 5 patients, 1 patient died after surgical treatment, and the remaining 4 patients were cured and discharged. Case 4 patient died of DIC and secondary ARDS.  The other patient’s pulmonary arterial pressure decreased after surgery. After post-operative treatment, they were discharged with no symptoms. The outpatients were followed up for 8 years, 5 years, 3 years and 1 year respectively (follow-up order since the first case). Cardiac function (NYHA) were recovered to grade I-II, and the left ventricular EF was 55-64 % recovery was good and they returned to the normal life.

Discussion

All patients underwent a first-stage surgical treatment after extensive discussion and adequate preoperative preparation.

The pathogenesis of pulmonary aneurysms has not been studied so far. Most of the tumors are in the pulmonary aorta and can be divided into combined and uncombined according to the combined arteriovenous traffic [6] .60% of patients with PAA are caused by genetic defects, 40% of which have hereditary hemorrhagic capillary vasodilation, leading to pulmonary capillary dysplasia, and few patients with infection due to infection, the location of the tumor is mainly in the peripheral pulmonary artery.

In this study, 3 of 5 patients had congenital heart disease, 1patient had pulmonary stenosis, and 1patient had a history of infection, 4 of which had different degrees of pulmonary hypertension. It is speculated that the pathogenesis is multi-factor-induced pulmonary vascular blood. Flow dynamics changes, arterial wall sclerosis, and cystic intimal layer degeneration, vascular smooth muscle destruction, fibrosis, thinning of the vascular artery wall, and vasodilation becomes a tumor. We believe that pulmonary hypertension, inflammatory damage and cystic middle layer destruction of the arterial wall are the main factors.

Once diagnosed as a pulmonary aneurysm, surgical treatment should be performed, and the surgical treatment must correct the cause of the abnormality together with the aneurysm. For patients with the previous history of infection, antibiotic treatment should be applied before surgery. Surgical procedures must take into account changes in the tumor site and accompanying malformations. There is no special treatment for the surgical treatment with malformation, but for the proximal pulmonary artery aneurysm, the aneurysm needs to be corrected under cardiopulmonary bypass, followed by pulmonary artery reconstruction or pulmonary artery replacement surgery. In this group of patients, the valve structure was not damaged during the operation, and the pulmonary artery circumcision was adopted. No regurgitation of the valve and stenosis of the outflow tract were observed during the follow-up. The long-term effect was still in follow-up.

Analysis, diagnosis, and treatment

Reported symptoms include hemoptysis, shortness of breath, chest pain, palpitations or syncopal episodes [9-12]. Additional symptoms attributed to extrinsic bronchial compression by a large PAA may include cough, worsening dyspnea, cyanosis or pneumonia [12-14]. Increase in the size of pulmonary artery more than 45 mm, there are chances to rupture of PAA.

Methods of diagnosis

The mainstay of imaging for both detection and follow-up of PAA remains computed tomography angiography (CTA). Given the nonspecific symptoms of PAA, CTA focus can be placed on either the pulmonary arterial system or the aorta and bronchial artery system. Multi-detector row CTA performed with bolus tracking over the descending aorta, along with coronal and sagittal multiplanar and maximum-intensity projection (MIP) reformatted images, has been reported as an imaging protocol for hemoptysis [15]. Other CTA imaging protocols call for bolus tracking over the main pulmonary artery [16] to optimize pulmonary artery opacification. The advantage of CTA is that it allows for the assessment of presence, size, location, and characteristics including saccular or fusiform aneurysm type [17]. CT pulmonary angiogram scans quality at relatively reduced contrast and radiation dose [18]. Catheter-directed angiography has been considered the gold standard for diagnosis of PAA. This allows for the determination of the extent of vascular involvement and an assessment of right-sided cardiac pressures [19].

Treatment

Several surgical techniques and procedures exist to treat PAAs. These include aneurysmorrhaphy, lobectomy, bilobectomy, aneurysmectomy and pneumonectomy [20]. Surgical resection, however, carries high risks, especially in patients with severe pulmonary hypertension [21]. When feasible, endovascular treatment can be offered as the first line therapy with the advantage of less morbidity and mortality. Although specific guidelines do not exist for endovascular versus surgical treatment of PAA, many case reports support first-line consideration of endovascular treatment when feasible. Endovascular therapy may best serve saccular PAA, both in the central and peripheral pulmonary arteries as suggested by published case reports. Alternatively, fusiform aneurysms of the peripheral pulmonary arteries may be treated endovascularly where pulmonary function and an adequate reserve is available, similar to peripheral pulmonary arteriovenous malformations. Central fusiform aneurysms, however, require surgical management.

In summary, the incidence of pulmonary aneurysms is low, clinically rare, and there are many clinically specific symptoms. Early detection is difficult. There are no clear guidelines for comprehensive diagnosis and treatment. This study comprehensively evaluates the patient’s condition after diagnosis to completely remove the aneurysm. The goal is reducing pulmonary vascular resistance and improving pulmonary blood flow is to select a suitable surgical method for active treatment and achieve a better curative effect. It is considered that protecting perioperative respiratory function is of great significance for improving prognosis.

Limitations of the study

As the PAA is a rare entity, there are no clear guidelines for comprehensive diagnosis and treatment. Our study had a small sample and in a time taking for each follow-up.

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