Embolisation for pulmonary arteriovenous malformation

Idiopathic pulmonary arteriovenous malformation: a rarity in clinical practice

Pulmonary arteriovenous malformations (PAVM) are characterized by abnormal pulmonary vessels forming arteriovenous shunts that compromise oxygenation of the blood, causing hypoxemia, and predispose to infections and cerebral ischemia. The patient in this case was a 38-year-old male who presented with tachypnea and dyspnea, cyanosis of extremities, and significant digital clubbing. The patient had structural epilepsy secondary to neurosurgery for a cerebral abscess during childhood. Arterial blood gas analysis showed significant hypoxemia (PaO2 = 46.2; SaO2 = 77%; PaO2/FiO2 = 70) and a chest computed tomography showed PAVM in the apical segments of the right upper and lower lobes, with ectatic and tortuous vascular structures following an intraparenchymal path, communicating with the pulmonary artery and veins. After confirmation of the PAVM, it was concluded that elevated pulmonary resistance was contributing to refractive hypoxemia and hypercapnia. Gradual reduction of the ventilation parameters, primarily controlled pressure and positive end-expiratory pressure, and consequent reduction of the arteriovenous shunt, resulted in progressive improvement of oxygenation and respiratory mechanics. The vascular surgery team's assessment was that treatment with embolization was warranted.

Update on pulmonary arteriovenous malformations

This review aimed to provide an overview of pulmonary arteriovenous malformations, including the major clinical and radiological presentations, investigation, and treatment algorithm of the condition. The primary etiology of pulmonary arteriovenous malformations is hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, with mutations in the ENG gene on chromosome 9 (HHT type 1) or in the ACVRL1/ALK1 complex (HHT type 2). Epistaxis should always be evaluated when repeated, when associated with anemia, and in some cases of hypoxemia. In the investigation, contrast echocardiography and chest CT are essential for evaluating this condition. Embolization is the best treatment choice, especially for correction in cases of hypoxemia or to avoid systemic infections. Finally, disease management was addressed in special conditions such as pregnancy. CT follow-up should be performed every 3-5 years, depending on the size of the afferent and efferent vessels, and antibiotic prophylactic care should always be oriented. Ultimately, knowledge of the disease by health professionals is a crucial point for the early diagnosis of these patients in clinical practice, which can potentially modify the natural course of the disease.

Significance of transesophageal contrast echocardiography with the agitated saline test for diagnosing pulmonary arteriovenous malformations

Objectives

This study evaluated the diagnostic value of transesophageal contrast echocardiography (TECE) with the agitated saline test for diagnosing pulmonary arteriovenous malformations (PAVMs) in comparison with chest CT or pulmonary angiography.

Background

Although transthoracic contrast echocardiography (TTCE) is the recommended screening test for diagnosing PAVMs, it has low specificity and positive predictive value. TECE is expected to offer improved sensitivity and specificity compared with TTCE, but no studies have reported the diagnostic accuracy and clinical significance of TECE in detecting PAVMs.

Methods and results

In total, 1,809 patients underwent TECE with the agitated saline test to evaluate symptoms of a suspected right to left shunt. Patients with hereditary hemorrhagic telangiectasia (HHT) were excluded. A total of 387 patients showed transpulmonary bubble passage, indicating a PAVM. Among them, 182 patients had additional chest CT or pulmonary angiography. Those patients were divided into two groups according to the presence of a PAVM in the radiologic imaging. A total of 18 patients (9.8%) were confirmed for the PAVM group. Only 13 patients required embolization for their PAVMs. The TECE with saline test results were divided into four grades according to the number of bubbles: grade 1 (n = 91), grade 2 (n = 47), grade 3 (n = 35), and grade 4 (n = 9). None of the patients in the PAVM group had grade 1 shunts in their TECE results. The positive predictive values for the presence of a PAVM according to the TECE grade scale were 10.6% for grade 2, 22.8% for grade 3, and 55.6% for grade 4.

Conclusion

TECE with a grade scale is a useful method for initially diagnosing PAVMs in non-HHT patients with a suspected right to left shunt. The findings of this study also suggest that patients with a small grade (<10 bubbles) shunt in their TECE findings should be spared unnecessary radiation exposure from CT scans or pulmonary angiography.

Pulmonary arteriovenous malformations presenting with upper back pain in an adult: A case report and literature review

Pulmonary arteriovenous malformations (PAVMs) are the abnormal connections between the pulmonary artery and pulmonary veins branches without intervening in the pulmonary vascular bed. Although the most common cause of PAVMs is hereditary hemorrhagic telangiectasia, the etiology of single PAVMs appears to be idiopathic. Dyspnea, cyanosis, cerebrovascular events, and brain abscess are the common clinical manifestations of these lesions, though they may present with a nonspecific symptom as upper back pain. Computed tomography is the gold standard investigation for diagnosing pulmonary arteriovenous malformations, and demonstrating their size and extent before therapy. Transcatheter embolization is the first-choice treatment for patients without severe complications. Surgical intervention is reserved for the lesions not amenable to embolotherapy.

Safety of Catheter Embolization of Pulmonary Arteriovenous Malformations-Evaluation of Possible Cerebrovascular Embolism after Catheter Embolization of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia/Osler Disease by Pre- and Post-Interventional DWI

BACKGROUND

This paper aimed to prospectively evaluate the safety of embolization therapy of pulmonary arteriovenous malformations (PAVMs) for the detection of cerebral infarctions by pre- and post-interventional MRI. Method One hundred and five patients (male/female = 44/61; mean age 48.6+/-15.8; range 5-86) with pre-diagnosed PAVMs on contrast-enhanced MRA underwent embolization therapy. The number of PAVMs treated in each patient ranged from 1-8 PAVMs. Depending on the size and localization of the feeding arteries, either Nester-Coils or Amplatzer vascular plugs were used for embolization therapy. cMRI was performed immediately before, and at the 4 h and 3-month post-embolization therapy. Detection of peri-interventional cerebral emboli was performed via T2w and DWI sequences using three different b-values, with calculation of ADC maps. Results Embolization did not show any post-/peri-interventional, newly developed ischemic lesions in the brain. Only one patient who underwent re-embolization and was previously treated with tungsten coils that corroded over time showed newly developed, small, diffuse emboli in the post-interventional DWI sequence. This patient already had several episodes of brain emboli before re-treatment due to the corroded coils, and during treatment, when passing the corroded coils, experienced additional small, clinically inconspicuous brain emboli. However, this complication was anticipated but accepted, since the vessel had to be occluded distally. Conclusion Catheter-based embolization of PAVMs is a safe method for treatment and does not result in clinically inconspicuous cerebral ischemia, which was not demonstrated previously.

Surgical lobectomy of pulmonary arteriovenous malformations in a patient with presentations regarded as sequela of tuberculosis: a case report

Background

Pulmonary arteriovenous malformations are uncommon conditions of abnormal communications between pulmonary arteries and veins, which are most commonly congenital in nature. Although such condition is not extremely rare, it is a challenge to the differential diagnosis of pulmonary problems such as hypoxemia and pulmonary lesions.

Case presentation

We report a meaningful case of a 23-year-old male presented with elevated hemoglobin (23.0 g/dl) on admission. Physical examination revealed cyanosis, digital clubbing and low oxygen saturation on room air. The patient was initially diagnosed as polycythemia vera while the subsequent result of bone marrow aspiration was negative. During further assessment, pulmonary arteriovenous malformations were detected by CT pulmonary angiography. Lobectomy was successfully performed with significant increase in oxygen saturation from 86 to 98%. The hemoglobin decreased to almost normal level of 14.9 g/dl 3 months after surgery and the patient had been followed up for nearly 5 years.

Conclusions

Pulmonary arteriovenous malformations should be suspected in patients with central cyanosis, digital clubbing, polycythemia, pulmonary lesion and without cardiac malformations. Embolization or surgery is strongly recommended to reduce the risks caused by pulmonary arteriovenous malformations.

Pulmonary arteriovenous malformation in a pediatric patient with epistaxis and hypoxemia

Hereditary hemorrhagic telangiectasia (HHT; also known as Osler-Weber-Rendu syndrome) is an inherited vascular disorder with a spectrum of clinical manifestations depending on lesion distribution. Epistaxis, mucocutaneous telangiectasia, and gastrointestinal bleeding are most common. Patients with pulmonary arteriovenous malformations are at serious risk of cerebral embolic stroke and abscess due to paradoxical embolism, indicating the need for early diagnosis and intervention. Herein, we report a 14-year-old boy who presented to his pediatrician's office with hypoxemia and personal history of epistaxis, family history of HHT, and radiologic workup demonstrating pulmonary and cerebral arteriovenous malformations. He was diagnosed with HHT and treated by endovascular embolization.

[Cyanosis for more than 4 years in a girl aged 4 years and 3 months]

A girl, aged 4 years and 3 months, presented with cyanosis of the lips shortly after birth. She then experienced shortness of breath after activity 1 year ago and acrocyanosis 3 months ago, with obvious acropachy and toe deformity. Laboratory examinations revealed an increase in hemoglobin (178 g/L) and a reduction in arterial partial pressure of oxygen (37.7 mm Hg). Plain and contrast-enhanced CT scans of the lungs showed a large area of dense shadow and multiple nodules with clear boundaries in the right lower lung, as well as thickening of the arteries and dilatation of the veins in the right lower lung. Magnetic resonance angiography of the pulmonary artery showed large arteriovenous malformation in the lung. The child was diagnosed with congenital pulmonary arteriovenous fistula and was given interventional embolization of the pulmonary arterial fistula. The child was followed up at 3 months after surgery. The symptoms of shortness of breath and cyanosis disappeared, and activity tolerance, heart rate, hemoglobin, red blood cell count, and transcutaneous oxygen saturation all returned to normal.

[Cyanosis for more than 4 years in a girl aged 4 years and 3 months]

A girl, aged 4 years and 3 months, presented with cyanosis of the lips shortly after birth. She then experienced shortness of breath after activity 1 year ago and acrocyanosis 3 months ago, with obvious acropachy and toe deformity. Laboratory examinations revealed an increase in hemoglobin (178 g/L) and a reduction in arterial partial pressure of oxygen (37.7 mm Hg). Plain and contrast-enhanced CT scans of the lungs showed a large area of dense shadow and multiple nodules with clear boundaries in the right lower lung, as well as thickening of the arteries and dilatation of the veins in the right lower lung. Magnetic resonance angiography of the pulmonary artery showed large arteriovenous malformation in the lung. The child was diagnosed with congenital pulmonary arteriovenous fistula and was given interventional embolization of the pulmonary arterial fistula. The child was followed up at 3 months after surgery. The symptoms of shortness of breath and cyanosis disappeared, and activity tolerance, heart rate, hemoglobin, red blood cell count, and transcutaneous oxygen saturation all returned to normal.

POSSIBILITIES OF USING MINIINVASIVE CATHETER TECHNOLOGIES IN THE TREATMENT OF LUNG BLEEDING

Aim – improve the results of the treatment of patients with pulmonary bleeding through widespread use of endovascular surgery methods for hemostasis. Materials and methods. Method of endovascular embolization of bronchial arteries is widely used in our clinic SI «Zaycev V. T. Institute of General and Emergency surgery of NAMS of Ukraine» not only as independent surgery in patients with LB, but also as way of preparation of patients with lung bleeding for planned thorax surgery. The most of the often spread nosological forms complicated by bleeding in our research were polycystic lung disease, chronic obstructive pulmonary disease, bronchiectasis disease, community-acquired pneumonia. Indications to the сatheter embolization procedure of bronchial arteries are the following: conservative treatment failure, hemoptysis in patients with bilateral inflammatory processes who was not prescribed surgical treatment for a range of reasons, absence of gross structural changes, lung resection, mainly in patients with oncologic lung injury, at massive and life-threatening profuse bleedings as a mean of temporary or constant hemostasis. Discussed treatment method is applied only in bleeding or within a 6 – 12 hour after its treatment. Successful result in embolization can be obtained in 79–99 %. Results. As a result of complete physical examination of patients with LB, it has been established that lung hemorrhage was the result of obstructive bronchitis in 14 patients (42 %), there was chronic obstructive pulmonary disease in 7 (21 %) patients and bronchiectasis was diagnosed in 6 (18 %) patients. In 2 (6 %) patients pulmonary hemorrhage was caused by community-acquired pneumonia. Central lung cancer was detected in 4 (12 %) patients. Conclusion. Therefore bronchial artery angiography gives high efficiency in solving the problem of hemostasis in oncological and nonspecific lung diseases, for determination of localization and source of bleeding. Endovascular occlusion of bronchial arteries in pulmonary hemorrhage permits: – to elaborate diagnosis because of the presence of specific angiographic signs of malignant tumour; – to perform effective endovascular hemostasis; – to gain time for stabilization the patient with the aim of planned surgical treatment.

Successful treatment of multiple pulmonary arteriovenous fistulae with thoracoscopy

Congenital pulmonary arteriovenous fistulae occur as a result of abnormal blood vessel development in the lungs. Blood takes a short pass from the pulmonary artery to veins. Multiple pulmonary arteriovenous fistulae are a rare occurrence, especially when involving both lungs. Fistulae located at the edge are prone to rupture and bleeding. We discuss a case of a 15‐year‐old overweight male with multiple pulmonary arteriovenous fistulae successfully treated with wedge‐shape excision via video‐assisted thoracoscopic surgery.