Pulmonary embolism (PE) in chronic obstructive pulmonary disease (COPD) patients often results in rapid decrease saturation and increase dyspnea requiring mechanical ventilation like an acute exacerbation [1]. The incidence of PE in hospitalized COPD patients ranges from 5.9% to 29.1% [2,3]. PE in COPD patients is associated with rapid worsening of symptoms and decreased survival and requires closed monitoring and intensive care. Therefore, they require advanced treatment that includes rapid recanalization using a catheter-directed thrombolysis (CDT) or mechanical thrombectomy. Mechanical thrombectomy devices available worldwide include the Flowtriever system (Inari Medical, Irvine, California), the Penumbra Indigo embolectomy system (Penumbra Inc, Alameda, California), the AngioVac catheter (Angiodynamics, Latham, New York), and the Angiojet catheter (Boston Scientific, Marlborough, MA, USA) [4]. While the AngioJet^® PE catheter has been used for acute PE, it is currently black labelled by the FDA due to reported complications ranging from arrhythmias to mortality. In South Korea, where the above catheter systems are not available, we would introduce a successful case report of the use of the AngioJet^® Solent 6Fr (Boston Scientific, Marlborough, MA, USA) for the safe and effective treatment of PE in a COPD patient.

A 72-year-old man was admitted two days ago with complaints of left lower extremity edema. He had T2DM and severe COPD and was often treated with steroids and inhaled medications for COPD, and usually used home ventilation. On physical examination, he had a non-pitting edema of the left leg. Laboratory tests showed a d-dimer of 2,459 ng/ml, anti-thrombin level was 52% and arterial blood gas analysis (ABGA) showed pH 7.32, PaCO2 65.8 mmHg, PaO2 61 mmHg and SaO2 88% (Table 1). Subsequent doppler ultrasound showed non-compressible popliteal and femoral veins and absence of blood flow. Computed tomography (CT) venography showed deep vein thrombosis (DVT) extending to the left (Lt.) common iliac vein (CIV) with iliac vein compression syndrome and concomitant PE (Fig. 1). The patient had active bleeding from the celiac artery branch vessel about 3 weeks ago, and thrombolysis was not performed. Therefore, we decided Celect^® Platinum Vena cava filter (Cook, Bloomington, IN, USA) insertion and mechanical thrombectomy and stent deployment, Lt. CIV were performed simultaneously with anticoagulation start carefully (Fig. 2). On the 1st day after the procedure, the patient showed signs of acute exacerbation of severe COPD and was transferred to the intensive care unit with complaints of dyspnea and unable to maintain oxygen saturation at fraction of inspired oxygen (FiO₂) 80%. The next day, despite a high FiO2 (80%), the patient developed respiratory failure, requiring further intervention. He had a pulmonary embolism severity index (PESI) score of 272, placing him in the very high-risk group, with a 30-day mortality rate of 10.0%–24.5%. His blood pressure was below 90/57 mmHg, heart rate was 110–120 per minute, and respiratory rate was 30–35 per minute. Due to the unavailability of the AngioJet^® PE catheter in South Korea, an AngioJet^® Solent catheter as an alternative device was used for mechanical thrombectomy. A 6Fr Rabbe catheter was placed via the right (Rt.) common femoral vein (CFV) at the suprarenal level. The Rt. main pulmonary artery was selected using a 5Fr Cobra catheter and 0.035 guidewire (GW). Pulmonary angiography showed thrombi in the arteries supplying the middle and lower lobes. Mechanical thrombectomy was performed for 44 seconds, resulting in successful recanalization and improved oxygen saturation (Fig. 3). The patient improved significantly the following day and was transferred to a general ward. He was discharged without complications after taking oral anticoagulants. Approximately 6 months later, follow-up CTA showed the complete resolution of DVT and PE, and anticoagulation was discontinued.

Figure 1. Initial CT angiography showed extensive deep vein thrombosis in left common iliac vein (A, yellow arrow) Rt. middle & lower lobe segmental artery pulmonary thromboembolism (B, blue arrow).

Figure 2. In supine position, IVC filter insertion was performed via Rt. IJV (A, red arrow). In prone position, angiography was initially undertaken through a 10-Fr sheath and It showed multiple filling-defect from popliteal vein to CIV (B, yellow arrow). Mechanical thrombectomy with AngioJet Zealante was performed, followed by self-expendable stent to Lt. CIV (C, green arrow).

Figure 3. Arteriography was initially undertaken through a 6-Fr Rabbe sheath and a pigtail catheter was placed up to the main pulmonary vein. Pulmonary angiography showed thrombi in the arteries supplying the middle and lower lobes (A, C; yellow head). Mechanical thrombectomy was performed, resulting in successful recanalization and completion angiography showed that thrombus disappeared without distal embolism (B, D; blue head).

Table 1 . Patient characteristics and initial laboratory results.

	Result	Reference value
Patient characteristic
Weight (kg)	74.4
Height (m)	1.702
Body mass index (kg/m2)	1.88
Oxygen saturation, SpO2 (%)	88%
Laboratory test
White blood cell (μl)	5,710	3,800–10,000
Hemoglobin (g/dl)	10.6	13.5–17.5
Platelet count (μl)	195K	130–400K
D-dimer (μl/ml)	2,459	0–243
Cardiac biomarker
CK-MB (ng/ml)	1.9	0.6–6.3
hsTnI (pg/ml)	25.3	2.3–17.5
NT-ProBNP (pg/ml)	262.8	0–125
ABGA
pH-pCO2-pO2-SpO2	7.32-65.8-61-88%

The incidence of venous thromboembolism (VTE) in Asians is 13.8 to 19.9 per 100,000, which is approximately 15% to 20% of the prevalence in Caucasians, specifically, White and Keenan reported that Asian Americans have a VTE incidence rate of approximately 1/5 that of Caucasians [5,6]. This marked difference in prevalence often leads to an underestimation of the prognostic significance of pulmonary embolism (PE) in Asian patients. In clinical practice, it is uncommon for patients with PE, even those with main pulmonary artery occlusion, to present with severe dyspnea or oxygen desaturation requiring mechanical ventilation. However, patients with severe chronic obstructive pulmonary disease (COPD) have a markedly different clinical course during acute exacerbations complicated by VTE compared with healthy adults. The clinical manifestations of COPD patients with PE during acute exacerbations are often more severe and more rapidly progressive than those observed in healthy individuals with PE. This increased severity can be attributed to the impaired pulmonary reserve and altered cardiopulmonary dynamics inherent to COPD patients [7]. The combination of PE and COPD exacerbation can lead to a synergistic deterioration in respiratory function, potentially resulting in acute respiratory failure, hemodynamic instability, and an increased risk of mortality [8]. Therefore, despite the lower overall incidence of VTE in Asian populations, clinicians should maintain a suspicion for PE in COPD patients presenting with acute exacerbations, particularly if the clinical deterioration appears disproportionate to the severity of the COPD exacerbation alone. Early diagnosis and management of PE in this patient population is critical to improving outcomes and reducing morbidity and mortality associated with this potentially life-threatening complication. PE in COPD patients is associated with poor outcomes and increased mortality. The incidence of PE in hospitalized COPD patients ranges from 5.9% to 29.1%, with rapid worsening of symptoms and decreased survival. This high incidence and poor prognosis highlight the urgent need for effective treatment strategies [7].

CDT and mechanical thrombectomy have emerged as promising treatment options for acute PE, particularly in cases of massive or submassive PE. These techniques offer several advantages compared to traditional treatment options. These techniques have been shown to remove thrombus faster than other treatment modalities, potentially improving Rt. Ventricular function and leading to faster clinical improvement. It allows for localized delivery of thrombolytics, reducing the systemic dose and the risk of bleeding complications. It also can be used in patients with contraindications to systemic thrombolysis, potentially reducing mortality in high-risk PE patients [9-11]. The Flowtriever system (Inari Medical, Irvine, California), the Penumbra Indigo embolectomy system (Penumbra Inc, Alameda, California), and the AngioVac catheter (Angiodynamics, Latham, New York), and the Angiojet catheter (Boston Scientific, Marlborough, MA, USA) is a well-known device for CDT and mechanical thrombectomy. Among them, the Angiojet catheter has several potential advantages over other devices. Angiojet catheter combines pharmacological thrombolysis with mechanical thrombectomy, potentially enhancing efficacy, it reduces procedural time and is associated with less blood loss during the intervention. It is easy for practitioners to use the catheter because the catheter’s enhanced flexibility allows for better navigation in tortuous vessels [12]. However, potential complications such as transient bradycardia and hypotension require careful patent monitoring during the procedure. Recent meta-analyses suggest that the overall safety profile of AngioJet in PE may be better than previously thought, with lower rates of major bleeding and other complications compared to earlier reports [13-15]. However, the Flowtriever system (Inari Medical, Irvine, California), the Penumbra Indigo embolectomy system (Penumbra Inc, Alameda, California), and the AngioVac catheter (Angiodynamics, Latham, New York) are not available for PE in the South Korean health insurance system. The AngioJet catheter (Boston Scientific, Marlborough, MA, USA) can be used, but not the AngioJet^® PE catheter. Using a non-pulmonary Angiojet catheter, which is the only one available in South Korea, Jo et al. reported safe removal of thrombus burden in a patient with PE [13]. We also safely performed mechanical thrombectomy in our patient. However, because of the reported complications, EKG monitoring is necessary, and bradycardia should be anticipated. The cost of thrombectomy performed with the Angiojet system was approximately four million won. However, when used in patients with DVT, it is covered by health insurance and costs about nine hundred thousand won. There are no catheters available in South Korea for patients with PE. It is an alternative treatment to improve survival in high-risk patients with high mortality rates.

In conclusion, while the AngioJet system shows promise for PE treatment in COPD patients, its use should be considered carefully on a case-by-case basis. Further research is needed to define its role in this challenging clinical scenario and to establish clear guidelines for its safe and effective use.

The authors declare no conflicts of interest.