Embolization of pulmonary AVMs of feeding arteries less than 3 mm: reports of two cases and an 8-year follow-up without embolization

Imaging to intervention: a review of what the Interventionalist needs to Know about Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a disorder that affects 1 in 5000-10,000 people worldwide and can result in devastating complications such as cerebral abscess, stroke, massive hemorrhage, and even death. HHT is an autosomal dominant disorder that leads to the formation of abnormal communication between the arteries and veins with a resultant spectrum of vascular anomalies. The disorder affects many organ systems and thus requires a dedicated multidisciplinary approach. Interventional radiologists are vital members of this team providing expertise not only in disease management, but in complex embolotherapy, helping to maintain the health of these patients. This article reviews clinical manifestations, screening guidelines, diagnostic criteria, and endovascular management of HHT.

MVP™ Micro Vascular Plug Systems for the Treatment of Pulmonary Arteriovenous Malformations

PURPOSE

To describe our institutional experience with MVP™ micro vascular plug systems for the treatment of pulmonary arteriovenous malformations (PAVMs).

MATERIALS AND METHODS

We performed a retrospective medical record review of 52 patients with 119 PAVMs treated exclusively with MVP™ systems (69 procedures/153 MVP™ systems) between July 2014 and July 2018. All patients had PAVMs with feeding artery diameters ≥ 2 mm. MVP™ systems were deployed according to physician preference. We collected patient demographic information; procedural data (including size of feeding artery, size and number of embolics used per PAVM, fluoroscopy time, contrast administration), technical success rates, complications, and persistence. Persistence was assessed using computed tomography angiography (CTA) performed 1-3 months and 3-5 years after embolization per clinical protocol.

RESULTS

All procedures were technically successful without major complications. Mean feeding artery diameter was 3.3 ± 1.2 mm. Mean fluoroscopy time per procedure and contrast volume administered per procedure were 35 ± 16 min and 217 ± 101 mL, respectively. A mean of 1.3 ± 0.8 MVP™ systems was used per PAVM. There were no instances of persistence during a mean follow-up time of 328 ± 258 days (range 26 to 914 days).

CONCLUSIONS

For PAVMs with feeding artery diameters of 2 to 7.9 mm (mean 3.3 ± 1.2 mm), MVP™ systems are safe and effective given their high technical success rates and lack of persistence. Further prospective work will be required to elucidate the advantages and disadvantages of these MVP™ systems for PAVM embolization.

LEVEL OF EVIDENCE

Level III.

Preliminary experience with the micro vascular plug for the treatment of pulmonary arteriovenous malformation: case series of four patients

Background

To describe the preliminary experience using Micro Vascular Plug (MVP) for treatment of pulmonary arteriovenous malformations (PAVMs) with small feeding arteries (3 -5 mm) in four patients with Hereditary Haemorrhagic Telangiectasia (HHT).

Material and methods

One female and three male patients with PAVMs have been treated during 2017. The mean age was 32.5 years; (range: 20-53). All patients underwent contrast echocardiography and computed tomography of the chest to establish the diagnosis.

Results

Four patients with PAVMs were treated with embolisation using the MVP-3Q and MVP-5Q micro plugs. All MVP were placed without complications and with following immediate occlusion of the PAVMs in all three cases. In one case MVP was placed semi selectively. All cases were with the good clinical outcomes.

Conclusion

MVP is a new detachable embolisation material which is easy to use. Maximal control during the deployment and immediate occlusion of the target vessels can be achieved.

A Rare Case of Cerebral Air Embolism Caused by Pulmonary Arteriovenous Malformation After Removal of a Central Venous Catheter

Cerebral air embolism following central venous catheter (CVC) removal is extremely rare. We report a case of cerebral air embolism with loss of consciousness after removal of CVC caused by pulmonary arteriovenous malformation (PAVM). Computed tomography revealed air bubbles in the internal carotid arteries along the sulci in the cerebral hemispheres, as well as a PAVM. The cerebral air embolism was treated with hyperbaric oxygen and intravenous thrombolytic therapy, and transcatheter embolization of the PAVM was performed. When inserting/removing CVC in a patient with a small PAVM, treatment of the PAVM, irrespective of its size, could prevent the type of complication that occurred in our present case.

Pulmonary arteriovenous malformations: a radiological and clinical investigation of 136 patients with long-term follow-up

AIM

To assess the clinical outcome of patients with and without hereditary haemorrhagic telangiectasia (HHT) after embolisation of pulmonary arteriovenous malformations (PAVM) from a single national centre.

MATERIALS AND METHODS

The present register-based observational study including all patients with PAVM treated with embolisation at a reference centre for HHT and PAVM was undertaken over a 20-year period. Demographic data, HHT genotyping, clinical presentation, and outcome were registered. Patients with HHT were compared to the patients without HHT. Clinical examination, contrast-enhanced echocardiography, and computed tomography (CT) were used to assess the clinical outcome at follow-up.

RESULTS

One hundred and thirty-six patients with 339 PAVM underwent embolisation during the study period: 22 did not have HHT; 62% had HHT1, 10% had HHT2, 4% had JP-HHT, 8% had clinical HHT without identified genetic mutations. Solitary PAVM were more common among patients without HHT than with HHT. Mean follow-up after the first embolisation was 58 months. Mean age at first embolisation was 46.5 years, and at last follow-up 51.8 years. The clinical success without shunt at follow-up was 87%. The 30-day mortality related to the embolisation was 0%. Twenty patients died during follow-up (mean age 69 years). Most patients could be treated during one session, but many will need a long follow-up with repeated clinical examinations and embolisation.

CONCLUSION

The majority of patients referred for embolisation of PAVM had HHT. Multiple PAVM is associated with HHT. Patients with PAVM should be screened for HHT and patients with HHT for PAVM. Embolisation is a safe procedure with high clinical success.

First use of Micro Vascular Plugs in Australia: Endovascular treatment of pulmonary arteriovenous malformation

This report describes the first Australian experience with the Micro Vascular Plug System (MVP), as a permanent embolic device for the treatment of pulmonary arteriovenous malformations (PAVMs). MVPs deployed in small vessels between 2 mm and 5 mm are demonstrated to be feasible, safe and effective treatment for PAVMs.

Implications of an Incidental Pulmonary Arteriovenous Malformation

Introduction. Pulmonary arteriovenous malformations (PAVMs) have been associated with life-threatening complications, such as stroke and massive hemoptysis, thus posing significant morbidity if left untreated. We report a case of an incidental finding of a PAVM in a trauma patient newly recognized to have suspected hereditary hemorrhagic telangiectasia (HHT). Case Description. A 34-year-old man with a history of recurrent epistaxis presented with a sudden fall associated with seizure-like activity. Trauma imaging showed a large subdural hematoma and, incidentally, a serpiginous focus within the right upper lobe with a prominent feeding artery consistent with a PAVM. The patient was diagnosed with a simple PAVM related to possible or suspected HHT, an autosomal dominant trait with age-related penetrance. He underwent a pulmonary arteriography of the right upper and lower lobe with the use of a microcatheter system; however, the PAVM could not be visualized. Thus, he was managed medically. The patient was educated on the need for prophylactic antibiotics prior to dental procedures and surveillance imaging. Discussion. Our case highlights the importance of obtaining a complete past medical and family history in young patients with a history of recurrent epistaxis to elicit features of HHT. The diagnosis can be made clinically and directly affects family members, who would otherwise not receive appropriate screening.