treatment of pulmonary arteriovenous malformations (pavms)

Univ.-Prof. Dr. med. René Müller-WilleUNIVERSITY MEDICAL CENTER GÖTTINGEN

Treatment of pulmonary arteriovenous Malformations (PAVMs)

René Müller-Wille

I n t e r v e n t i o n a l R a d i o l o g y

U n i v e r s i t y M e d i c a l C e n t e r G ö t t i n g e n

LINC Leipzig

30. January 2018


PAVM Brief description

• Direct capillary-free communication between pulmonary arteries and pulmonary veins

• Abnormal intrapulmonary right-to-left shunt (high-flow, low pressure)

• Most PAVMs are hereditary and occur in hereditary hemorrhagic telangiectasia (70% - 90%)

• PAVMs tent to increase with time


Hereditary hemorrhagic telangiectasia (HHT)Rendu-Osler-Weber-Syndrom

Curacao Criteria:

1. Recurrent epistaxis

2. Mucocutaneus telangiectasia

3. Visceral involvement (AVMs)

– PAVMs (30% of patients, type 1)

– Hepatic AVMs (30% of patients)

– Cerebral/spinal AVMs (about 10% of patients)

4. Affected first degree relative (autosomal dominant pattern)


Complications of PAVM

1. Right-to-left shunting → Hypoxemia

– Dyspnea/Cyanosis

– Nail clubbing

– Polycythemia

2. Absence of filtering capillary bed → Paradoxical embolism of air bubbles or clots

– Transient ischemic attack (TIA) or stroke

– Brain abscess

3. Rupture of abnormal vessels → Bleeding

– Hemoptysis

– Hematothorax


Imaging

• Contrast-enhanced echocardiography (bubble study)

• Chest radiography

• Computed tomography (CT)

• Magnetic resonance imaging (MRI)

• Pulmonary angiography


Imaging

“Incidental mass”


Imaging


Classification of PAVMs (WHITE and colleagues)

Simple (85%)

Complex(10%)

White RI Jr, Mitchell SE, Barth KH, Kaufman SL, Kadir S, Chang R, Terry PB. Angioarchitecture of pulmonary arteriovenous malformations: an important consideration before embolotherapy. Am J Roentgenol. 1983 Apr;140(4):681-6.


Diffuse PAVM


Therapy → Embolization first choice

• First reported by PORSTMANN 1977

• Goal: Embolization of the feeding artery as close tothe aneurysm sac as possible

Materials

• Coils

• Plugs

• (Detachabel Ballons)

Porstmann W. Therapeutic embolization of arteriovenous pulmonary fistula by catheter technique. In: Kelop O, editor. Current Concepts in Pediatric Radiology. Berlin: Springer; 1977. pp. 23–31.

© René Müller-Wille


Indication for Embolization

• Symptomatic PAVM

• Asymptomatic PAVM: Feeding artery > 3mm (however, arteries as 2-2.5 mm have caused symptoms!)

Goal:

• Improvement of hypoxemia

• Prevention of paradoxical embolism

• Prevention of hemorrhage

Left untreated, 50% of patients with PAVM will develop disabling or fatal complications!


Technical aspects of Embolization

• Femoral/jugular vein approach (7-8F)

• 5000 IU heparin/prophylactic antibiotics

• No air introduction during angiography (→ Sheaths and catheters were continuously flushed with saline)

• Diagnostic angiography

– High frame rate (6/sec)

– 20-50 ml (15 -25 ml/sec)

• Catheterization of the feeding artery with a guiding catheter/microcatheter (coaxial or triaxial)


Coils

• Tight packing of coils

– First coil > 20% oversizing

– „never too small“ → paradoxical embolization

– Smaller coils in the center

• Coil typ

– long

– fibered

– detachable

• “Anchor technique“ in high flow situation


Coiling → „never too small“


Anchor technique



Amplatzer Vascular Plug

AVP II

AVP VI


Application

0.056 in 0.038 in

AVP II AVP 4

→ 30% - 50% oversizing



Deployment


Kucukay F, Özdemir M, Şenol E, Okten S, Ereren M, Karan A. Large pulmonary arteriovenous malformations: long-term results of embolization with AMPLATZER vascular plugs. J Vasc Interv Radiol. 2014 Sep;25(9):1327-32.

“Treatment of large PAVMs with AVPs is an effective method for obtaining excellent long-term results.”


Rabellino M, Serra M, Peralta O, Rodriguez P, Gentile E, Levy-Yayati E, Kisilevzky N, Ulla M, García-Mónaco R. Early experience with the AMPLATZER vascular plug IV for the occlusion of pulmonary arteriovenous malformations. J Vasc Interv Radiol. 2014 Sep;25(9):1333-7

“At a mean follow-up of 20.1 months, no recanalization of PAVMs was observed”


Micro Vascular Plug (MVP)

Boatta E, Jahn C, Canuet M, Garnon J, Ramamurthy N, Cazzato RL, Gangi A. Pulmonary Arteriovenous Malformations Embolized Using a Micro Vascular Plug System: Technical Note on a Preliminary Experience. Cardiovasc Intervent Radiol. 2017 Feb;40(2):296-301.

“MVP embolization of PAVMs appears technically feasible, safe, and effective at early

follow-up.”


Plug versus coil?

“Coils were used for embolization in 37 PAVMs, Amplatzer plugs in 21, and both in five. Median follow-up time was 7.7 years (range 1.4-18.9). Recanalization was detected in seven vessels, all treated with coils;

there were no cases of re-canalization in plug-occluded vessels (p = 0.0413).”

Tau N, Atar E, Mei-Zahav M, Bachar GN, Dagan T, Birk E, Bruckheimer E. Amplatzer Vascular Plugs Versus Coils for Embolization of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia. Cardiovasc Intervent Radiol. 2016 Aug;39(8):1110-4.


Follow-up

• Annual clinical review

• Oxygen situation

• Contrast enhanced echocardiography

• CT-Scan (recanalization, new PAVM)

• In severe cases pulmonary angiography every 5 years

• Screen relatives for HHT


Take home massage

• Check for HHT

• Left untreated → 50% fatal complications

• Embolization first choice

• Technical aspects

– No air introduction during intervention

– Embolization of the arterial feeder as close to the sac

• Large diamater → AVP II

• Small diameter → Coil, AVP 4, MVP

– „never too small“ → paradoxical embolization


Thank you!

René Müller-Wille




Treatment of pulmonary arteriovenous Malformations (PAVMs)

René Müller-Wille



LINC Leipzig

30. January 2018

treatment of pulmonary arteriovenous malformations (pavms)

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