Novel diagnostic and therapeutic approaches to pulmonary hypertension due to the unilateral absence of a pulmonary artery

Congenital Isolated Unilateral Agenesis of Pulmonary Arteries with 3-Year Follow-Up after Initiation of Treatment

Background and objective: Unilateral agenesis of pulmonary arteries (UAPA) is a rare disease, with approximately 400 cases reported to date. UAPA is often associated with congenital heart disease, and the uncomplicated form is isolated UAPA, which accounts for approximately 30% of all cases of UAPA. The incidence of pulmonary hypertension due to UAPA has been reported to range from 19 to 44%. There is no consensus treatment for pulmonary hypertension associated with UAPA. We present the first reported case in which a three-drug combination, comprising of iloprost inhalation, riociguat, and ambrisentan, was administered to a patient with UAPA, and was followed-up for 3 years post-diagnosis. Case presentation: A 68-year-old Japanese woman presented to our hospital with dyspnea and chest discomfort. She underwent chest radiography, blood tests, and echocardiography; however, the cause of the patient's symptoms could not be identified. During regular follow-up, an echocardiography 21 months after the initial visit revealed elevated right ventricular pressure (peak tricuspid regurgitation velocity: 5.2 m/s and right ventricular systolic pressure: 120 mmHg) and a diagnosis of pulmonary hypertension was made. Contrast-enhanced computed tomography (CT) of the chest and a pulmonary blood flow scintigram were performed to investigate the cause of pulmonary hypertension, and isolated UAPA was diagnosed. The patient was treated with a three-drug combination of iloprost inhalation, riociguat, and ambrisentan and followed up for 3 years with good therapeutic outcomes. Conclusions: We present a case of pulmonary hypertension caused by isolated UAPA. Although rare, this disease can lead to pulmonary hypertension and should be treated cautiously. While there is no consensus regarding the treatment of this disease, a three-drug combination of iloprost inhalation, riociguat, and oral ambrisentan proved effective.

Surgical repair of unilateral absence of pulmonary artery in children with pulmonary hypertension: a single-center retrospective study

BACKGROUND

The early diagnosis of unilateral absence of pulmonary artery (UAPA) in children offers an opportunity for effective intervention. Due to the lack of clinical evidence, a consensus regarding surgical treatment has yet to be reported. The aim of this study is to evaluate the effectiveness and safety of pulmonary artery (PA) reconstruction with a "two-segment" technique to repair UAPA in patients with pulmonary hypertension.

METHODS

Intraoperatively, the ligamentum arteriosum connecting the innominate artery and distal PA was dissected and occluded. A conduit created by fresh autologous pericardium formed the first "segment" of the neo-PA. The second "segment" was a Gore vascular graft with integrated rings anastomosed between the proximal end of the pericardial conduit and the main pulmonary artery (MPA).

RESULTS

A total of five consecutive patients were included, and the absent PA was successfully reconstructed using the "two-segment" technique in all patients. Following revascularization, the direct measurement of the pressure in MPA during the operation showed that the average mean pulmonary artery pressure (mPAP) decreased from 31.3±16.0 to 16.8±4.2 mmHg (P=0.047). The average mPAP/radial mean arterial pressure (rMAP) ratio decreased from 0.59±0.27 preoperatively to 0.30±0.10 postoperatively (P=0.028). The mean follow-up period was 18.85±4.67 months. The median diameter of the reconstructed PA (pericardial segment) measured by transthoracic echocardiography (TTE) was 6.1 mm. One patient safely underwent a redo operation to repair relative stenosis in the neo-PA.

CONCLUSIONS

Early PA reconstruction may effectively alleviate pulmonary hypertension in children with UAPA. The "two-segment" technique is safe and can facilitate potential redo pulmonary arterioplasty. Anticoagulation and antiplatelet therapy, as well as frequent follow-up, is required after the operation.

Pulmonary hypertension in an adult with unilateral absence of left pulmonary artery

Unilateral absence of pulmonary artery is a rare congenital abnormality that occurs due to malformation of the sixth aortic arch during embryonic development. The clinical presentation of unilateral absence of pulmonary artery can vary based on age of diagnosis; however, in the adult population, it can present with a variety of manifestations including hemoptysis, recurrent pneumonia, and pulmonary hypertension or as an incidental finding. Diagnosis and management of unilateral absence of pulmonary artery remain a challenge. Here, we describe a case of a 37-year-old female with no known past medical history who presented with progressively worsening dyspnea and fatigue. She was incidentally found to have unilateral absence of pulmonary artery on computerized tomography angiography of the chest. Her imaging and physical exam demonstrated signs of volume overload and severe pulmonary hypertension. She received diuretics with good response and was discharged with referral to pulmonary hypertension clinic and eventual follow-up with right heart catheterization. In summary, we describe a rare congenital condition and highlight its diagnostic and therapeutic challenges.

Novel diagnostic and therapeutic approaches to pulmonary hypertension due to the unilateral absence of a pulmonary artery

We report the case of a 64‐year‐old female diagnosed with severe pulmonary hypertension due to the unilateral absence of a pulmonary artery. The four‐dimensional computed tomography scan is a useful modality for revealing detailed anatomical findings for differential diagnoses and surgical decision‐making. The patient had severe pulmonary hypertension with a mean pulmonary artery pressure (PAP) of 74 mmHg and was treated with triple upfront combination therapy, leading to significant improvement in pulmonary haemodynamics (to 27 mmHg in mean PAP) and functional capacity (WHO functional class, from III to II; 6‐min walk distance, from 211 to 276 m).