“Treat and repair” strategy for a giant pulmonary artery aneurysm caused by idiopathic pulmonary hypertension and compression of the left main coronary artery

Abstract

Compression of the left main coronary artery by a giant pulmonary artery aneurysm is a rare but potentially fatal condition, particularly in patients with pulmonary hypertension. Although percutaneous coronary intervention has been attempted, concerns remain regarding stent durability. Surgical intervention provides a definitive solution but carries high perioperative risks. A 67-year-old woman with idiopathic pulmonary arterial hypertension developed exertional chest tightness and left vocal cord paralysis. Imaging revealed a giant pulmonary artery aneurysm compressing the left main coronary artery, causing severe stenosis. Given the high surgical risk, preoperative medical therapy was initiated, successfully lowering pulmonary artery pressure. The patient then underwent pulmonary artery plication, main pulmonary artery conduit replacement, and left main coronary artery patch angioplasty—a unique combination rarely reported in this setting. Postoperative imaging confirmed an adequately expanded left main coronary artery without external compression. This case highlights a “treat and repair” strategy, in which pulmonary hypertension management optimized surgical safety. A multidisciplinary approach is essential, and long-term follow-up is needed to assess the durability of the reconstructed left main coronary artery.

Introduction

Pulmonary artery aneurysms (PAAs) associated with pulmonary hypertension (PH) are well-recognized conditions with reported rupture and dissection risks [1]. Reports of cases of left main coronary artery (LMCA) compression caused by giant PAAs have recently increased; this condition, recognized as a potentially lethal complication, lacks consistent treatment consensus [2].

Although percutaneous coronary intervention (PCI) for LMCA compression owing to PAAs has been reported, significant challenges remain, including recoil after balloon angioplasty, stent fracture, and stent migration. These limitations are particularly concerning owing to this condition’s potential to affect younger patients [3, 4]. In contrast, surgical intervention allows the simultaneous treatment of both LMCA compression and PAAs, offering a potentially more definitive and reliable solution. However, in clinical practice, cardiac surgery is associated with substantial risks in patients with underlying PH [5].

We report a case in which preoperative medical management optimally reduced pulmonary artery (PA) pressure, followed by surgical intervention using cardiopulmonary bypass (CPB) to address both LMCA compression and a giant PAA; this approach enabled safe and curative treatment outcomes.

Case report

A 67-year-old Japanese woman with a 16-year history of idiopathic pulmonary arterial hypertension (iPAH) began experiencing postprandial chest discomfort and exertional chest tightness approximately 4 years ago. Her iPAH was managed with a combination of three pulmonary vasodilators—beraprost, tadalafil, and bosentan—effectively controlling her symptoms in daily life. However, she developed hoarseness and episodes of choking 2 weeks before presentation, prompting a visit to a local otolaryngologist. She was diagnosed with left vocal cord paralysis and referred to our general hospital for further evaluation. Contrast-enhanced computed tomography (CECT) revealed a giant PAA, considered the cause of left recurrent laryngeal nerve compression and subsequent vocal cord paralysis. In addition, the CECT findings indicated compression of the LMCA by the giant PAA, which was suspected to be responsible for her exertional chest tightness. She was subsequently referred to the cardiology department for further management.

The patient was 157 cm tall, weighed 49.4 kg, and had normal vital signs. SpO₂ on room air was 98%. Chest X-ray revealed a cardiothoracic ratio of 54%, with significant enlargement of the left second arch (Fig. 1A). No remarkable abnormalities were observed from the blood tests, except for a mildly elevated B-type natriuretic peptide level of 31 pg/mL. Electrocardiography showed sinus rhythm with a heart rate of 67 bpm, right axis deviation, and signs of right ventricular (RV) hypertrophy. Echocardiography demonstrated no RV dilation, with trivial tricuspid regurgitation making RV systolic pressure estimation difficult. Left ventricular contraction was normal, with a left ventricular ejection fraction of 74.2%, no asynergy, and trivial mitral regurgitation. Right heart catheterization (RHC) revealed a mean right atrial pressure of 5 mmHg, PA pressure of 63/26 mmHg (mean 44 mmHg), RV pressure of 62/11 mmHg, pulmonary capillary wedge pressure of 9 mmHg, and pulmonary vascular resistance (PVR) of 7.1 Wood units. Coronary angiography showed no significant stenosis in the right anterior oblique/caudal view; however, the LMCA ostium exhibited 90% stenosis in the cranial view, suggesting slit-like narrowing (Fig. 1B). CECT showed a main PA aneurysm with a maximum short-axis diameter of 65 mm, with aneurysmal changes in the right and left PAs measuring 45 mm each (Fig. 1C). The LMCA takeoff angle from the left sinus of Valsalva was 8°, and the LMCA was compressed by the main PA and appeared slit-like, consistent with the coronary angiography findings (Fig. 1D). Although the patient was classified as American Society of Anesthesiologists Physical Status Class II, she was deemed as high risk for general anesthesia owing to the presence of moderate PH, with a systolic PA pressure of 63 mmHg and a mean PA pressure of 44 mmHg. To optimize the patient’s condition for surgery, cardiologists initiated preoperative medical management to lower the PA pressure.

Fig. 1.

Preoperative images. A Chest X-ray demonstrating significant enlargement of the left second arch. B Coronary angiography. Although no significant stenosis was evident in the right anterior oblique (RAO)/caudal view, the RAO 0°/cranial 20° view revealed 90% stenosis at the ostium of the left main coronary artery (LMCA), presenting as a slit-like stenosis (arrowhead). C Three-dimensional contrast-enhanced CT reconstruction showing a main pulmonary artery (PA) aneurysm with a maximum diameter of 65 mm and bilateral PA aneurysms with maximum diameters of 45 mm. D Contrast-enhanced CT demonstrating the LMCA takeoff angle to the left sinus of Valsalva measured 8°. The LMCA was compressed by the main PA, resulting in a slit-like appearance. MPA, main pulmonary artery; LPA, left pulmonary artery; RPA, right pulmonary artery

To enhance PH management, the treatment was switched to tadalafil, macitentan, and selexipag, with selexipag gradually titrated to the maximum dose. Following admission, RHC was performed at 2-week and 3-week intervals, resulting in a final reduction of PA pressure to 40/19 mmHg (mean 29 mmHg), RV pressure to 43/10 mmHg, and PVR to 4.2 Wood units (Fig. 2). Based on these findings, a planned approach was adopted, including staged surgical interventions: PA plication and main PA conduit replacement, with LMCA patch angioplasty performed as needed.

Fig. 2.

Changes in the mean pulmonary arterial pressure and PVR. The graph illustrates the mean pulmonary arterial pressures and PVR at admission, 2 weeks postadmission, and 3 weeks postadmission. Adm., admission

The surgery used a median sternotomy approach. CPB was established with arterial perfusion through the ascending aorta and venous drainage from the superior and inferior venae cavae. After heart decompression, retraction of the main PA provided a clear view of the LMCA. Although the LMCA appeared wide externally, it remained flattened after relieving compression, necessitating patch enlargement. Gross inspection revealed no congenital stenosis or intimal degeneration at the LMCA ostia, only morphological flattening. The main PA was transected just above the sinotubular junction, and pulmonary valve inspection revealed no annular dilation and well-preserved cusp morphology. To normalize the diameters of the right and left pulmonary arteries, consistent with the reference values for normal PA dimensions [6], wedge-shaped portions of the anterior walls were excised. Each PA was then plicated using 4–0 monofilament horizontal mattress running sutures and reinforced with an additional whipping suture layer.

The aorta was cross-clamped, and to achieve cardiac arrest, cardioplegia was administered antegradely and retrogradely. Subsequent doses of cardioplegia were administered retrogradely. A transverse incision was made on the anterior aorta and extended longitudinally toward the left coronary artery orifice, which appeared slit-like and compressed vertically. The incision was extended along the superior aspect of the LMCA to just proximal to the bifurcation of the left anterior descending and left circumflex arteries. A segment of the great saphenous vein, harvested and incised longitudinally, was fashioned into a 5-mm-wide crescent-shaped patch. Using 7–0 monofilament sutures, patch enlargement was performed with a single running suture from the distal LMCA. The LMCA was successfully expanded to accommodate a 6-mm sizer without resistance. A 28-mm Triplex® graft (Terumo Corp, Tokyo, Japan), a non-biodegradable coated graft, was used to match the proximal diameter of the main PA. Using 4–0 monofilament sutures, the distal end of the graft was anastomosed to the peripheral PA. After aortic cross-clamp release, the proximal end of the graft was anastomosed to the central PA using the same suture material.

CPB weaning was uneventful. Satisfactory opening of the LMCA was confirmed by epicardial and transesophageal echocardiography. After CPB weaning, direct measurement showed a systolic PA pressure of 38 mmHg when the systolic systemic blood pressure was 105 mmHg, resulting in a pulmonary-to-systemic systolic pressure ratio of 0.36.

The patient was extubated on postoperative day (POD) 1 and weaned off inhaled nitric oxide therapy on POD 10. Pericardial drainage was required on POD 14 owing to pericardial effusion. Additionally, the patient developed atrial fibrillation and atrial flutter, requiring the introduction of amiodarone and bisoprolol for rhythm control. Given the use of a saphenous vein patch, warfarin was initiated for anticoagulation; however, its dosage adjustment was prolonged due to interactions with amiodarone. Furthermore, the patient remained on oxygen therapy postoperatively, which was successfully discontinued on POD 20. After stabilization of her condition, she was discharged home on POD 33. Postoperative CECT imaging revealed a favorable PA morphology, with the LMCA adequately expanded and free from external compression (Fig. 3). At 1 year and 2 months postoperatively, the patient remains asymptomatic. A 12-lead electrocardiogram showed no ST-T changes suggestive of myocardial ischemia, and transthoracic echocardiography at 9 months demonstrated preserved systolic function without asynergy. Long-term clinical and radiological follow-up, including CECT, is ongoing to monitor the durability of the repair.

Fig. 3.

Intraoperative images and postoperative contrast-enhanced CT images. A Intraoperative view showing a slit-like LMCA orifice (arrowhead). B Intraoperative view of LMCA patch angioplasty using a saphenous vein patch (asterisk). C Postoperative contrast-enhanced CT, anterior view. D Postoperative contrast-enhanced CT, posterior view. LMCA, left main coronary artery

Discussion

We successfully performed definitive treatment for a giant PAA with LMCA compression associated with iPAH. Preoperative medical management reduced PA pressure and mitigated the risks of general anesthesia, allowing for safe surgical intervention addressing LMCA compression and the aneurysm.

In patients with pulmonary artery hypertension (PAH), extrinsic compression of the LMCA by a PAA is increasingly recognized as a cause of angina, and some centers are actively performing PCIs [2, 3]. In a single-center retrospective observational study by Galie et al., PCIs were performed on 45 cases with LMCA stenosis ≥ 50% caused by PAA compression. According to this study, the minimal luminal diameter and stenosis rate significantly worsened at 9 months after PCI, with five cases requiring reintervention owing to restenosis [3]. Mechanical recoil, stent restructuring, and neointimal proliferation are reported causes of restenosis. In addition, stent placement in the LMCA ostium carries the risk of stent displacement, which is a severe complication [3, 4]. Akbal et al. highlighted that extrinsic compression poses a major challenge to the radial force of the stent, raising concerns about the ongoing risk of progressive LMCA compression by an enlarged PAA [2].

Given these findings, stenting alone as PCI for LMCA compression caused by a PAA appears insufficient in terms of durability and curative potential. To achieve these goals, replacing the main PA with a prosthetic graft is crucial. If LMCA stenosis resolves solely by eliminating the PAA through graft replacement, further intervention on the LMCA may not be necessary. However, in cases such as this one, where LMCA stenosis has become fixed, patch angioplasty may be required to restore adequate coronary flow. While surgical management of PAA secondary to PAH has been previously described, the simultaneous reconstruction of the LMCA with patch angioplasty in this setting remains uncommon. Additionally, a mean PA pressure of > 40 mmHg has been reported to significantly increase mortality in cardiac surgery [5], highlighting the high risk associated with the patient’s initial condition upon admission.

A key aspect of this case is the preoperative reduction of PA pressure through targeted medical therapy before surgical intervention. The “treat and repair” strategy has been implemented previously in patients with congenital heart defects and moderate to severe PAH [7]. This approach involves initially improving PAH with medical therapy, followed by surgical or interventional “repair” of the cardiac defect [7]. Although Akagi et al. demonstrated the efficacy of this strategy in patients with left-to-right shunting defects, this case did not involve such conditions and thus differed fundamentally. However, the underlying concept remains similar: reducing cardiac surgery risks and improving the prognosis in patients with moderate to severe PAH through pulmonary vasodilator use [7].

Patch angioplasty offers several advantages over conventional coronary artery bypass grafting (CABG) for LMCA stenosis; it provides more physiological myocardial perfusion, eliminates the concern of competition with native flow, and preserves the bypass grafting option in the event of future atherosclerotic coronary artery disease [8]. Various materials can be used for the patch, including the saphenous vein, autologous pericardium, internal thoracic artery (ITA), and PA grafts [8]. Autologous pericardium, although readily available, is associated with calcification and subsequent restenosis risks owing to its lack of fibrinolytic properties [8]. In this case, the patient, being in her 60 s and relatively young, avoided the use of ITA to preserve options for future CABG, which was an appropriate decision. Because there was no viable PA wall available in this case, PA grafts were not considered. Although saphenous vein grafts have been associated with risks of dilation and long-term restenosis, Botsios et al. reported favorable outcomes in a retrospective study of 19 cases with up to 10 years of cardiac magnetic resonance imaging follow-up, showing no restenosis or aneurysmatic coronary formation [9]. However, owing to the limited data on outcomes > 10 years, careful and continuous follow-up remains essential for this patient.

Conclusion

Using a “treat and repair” strategy, we successfully managed severe LMCA compression caused by a giant PAA in the setting of moderate PAH. Preoperative medical treatment was used to reduce the PA pressure, enabling safe and definitive surgical intervention. Long-term follow-up of the reconstructed LMCA remains essential. Given the rarity of LMCA compression due to iPAH-associated PAA, further case accumulation is required to deepen our understanding and refine management strategies.

Author contributions

Yuchen Cao contributed to the conception of the study and manuscript drafting. Masayuki Goto contributed to manuscript revision and critical feedback. Takuya Maeda and Yoshifumi Kunii were involved in case management. Masaaki Koide supervised the study and provided final approval of the manuscript.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request. However, due to patient confidentiality and ethical considerations, the data cannot be publicly shared.

Declarations

Ethics Approval

Not Applicable.

Informed consent 

Informed consent was obtained from the patient to publish this report for academic interest.

Conflicts of interest

The authors declare that they have no conflict of interest.

Human and Animal Rights Statement

All procedures performed in study were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.