Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

Migrated coil expectorated 12 years after embolization of pulmonary arteriovenous malformation, due probably to abscess formation around the coil

Pulmonary arteriovenous malformations (PAVMs) are rare vascular structures providing direct capillary-free communications between pulmonary arteries and veins. Embolotherapy is indicated as a front-line therapy. We report an unusual long-term complication of coil embolization for a 44-year-old woman with hereditary hemorrhagic telangiectasia (HHT) who had repeatedly undergone the procedures for her PAVMs. She expectorated the coil which had been placed 12 years earlier and migrated to the bronchus according to the chest radiogram and bronchoscopy. Histology of the resected lung segment suggested the cavity communicating with the bronchus was the consequence of abscess formation around the coils. Even after technically successful embolization to PAVMs, long term follow-up should be necessary paying attention to the symptoms and imaging to avoid massive hemoptysis and subsequent emergency surgery.

[Brain abscess and Osler-Weber-Rendu syndrome: Do not forget to look for pulmonary arteriovenous malformations]

INTRODUCTION

Osler-Rendu-Weber syndrome or hereditary hemorrhagic telangiectasia affects between 1/5000 and 1/8000 people. It is characterized by presence of recurrent epistaxis, mucocutaneous telangiectasia and visceral arteriovenous malformations. It is a genetic disease with autosomal dominant transmission inducing an endothelial cells hyper-proliferation.

CASE REPORT

A 68-year-old women with Osler-Rendu-Weber syndrome was referred for management of general impairment with confusional syndrome and hyperthermia. Various examinations have allowed us to conclude at diagnosis of brain abscess with ventriculitis probably favored by right-left shunt secondary to pulmonary arteriovenous malformations. Evolution was favorable after antibiotic treatment and endovascular embolization.

CONCLUSION

In case of brain abscess without obvious promoting factor, don't forget to looking for a right-left shunt providing septic or aseptic emboli. Furthermore, diagnosis of Rendu-Osler-Weber syndrome should be considered presence of telangiectasias and/or epistaxis.

Reperfusion of Pulmonary Arteriovenous Malformations Following Embolotherapy: A Randomized Controlled Trial of Detachable Versus Pushable Coils

PURPOSE

To compare 1 year post-embolization reperfusion rates in pulmonary arteriovenous malformations (PAVMs) treated with the 0.035″ Interlock™ Fibered IDC™ Occlusion System coils (IDC) (Boston Scientific, Marlborough, Massachusetts) versus 0.035″ Nester coils (Cook Medical Inc., Bloomington, Indiana).

MATERIALS AND METHODS

A randomized controlled trial was performed randomizing individual PAVMs to treatment with IDC versus Nester coils at the largest hereditary hemorrhagic telangiectasia center in Canada. The primary outcome was CT evidence of reperfusion at 1 year. Secondary outcomes included periprocedural complications, fluoroscopy time and contrast volume.

RESULTS

Our study was terminated prematurely due to slow recruitment and subsequent expiration of funding. A total of 46 PAVMs in 25 patients (64% female) were included in our study; 26 randomized to Nester coils and 20 randomized to IDC. One patient was lost to follow-up. At a mean follow-up of 421.2 ± 215.7 days, no significant difference in PAVM reperfusion was detected between Nester coils and IDC (0% vs. 5.6%, p > 0.05). No major periprocedural complications were noted in either group. Fluoroscopy time (Nester: 15.0 ± 11.8 min vs. IDC 16.0 ± 5.4 min, p > 0.05) and contrast volume (Nester: 80.3 ± 36.5 ml vs. IDC 87.3 ± 51.7 ml, p > 0.05) utilized did not differ between groups.

CONCLUSION

No significant difference was detected in PAVM reperfusion rates, periprocedural complication rates, contrast volume utilization or fluoroscopy time following embolization with IDC and Nester coils.

Pulmonary arteriovenous malformations in hereditary haemorrhagic telangiectasia: Correlations between computed tomography findings and cerebral complications

OBJECTIVES

Computed tomography (CT) is the modality of choice to characterise pulmonary arteriovenous malformations (PAVMs) in patients with hereditary haemorrhagic telangiectasia (HHT). Our objective was to determine if CT findings were associated with frequency of brain abscess and ischaemic stroke.

METHODS

This retrospective study included patients with HHT-related PAVMs. CT results, i.e. PAVM presentation (unique, multiple, disseminated or diffuse), the number of PAVMs and the largest feeding artery size, were correlated to prevalence of ischaemic stroke and brain abscess. All CTs were reviewed in consensus by two radiologists.

RESULTS

Of 170 patients, 73 patients had unique (42.9 %), 49 multiple (28.8 %), 36 disseminated (21.2 %) and 12 diffuse (7.1 %) PAVMs. Fifteen patients presented with brain abscess; 26 patients presented with ischaemic stroke. The number of PAVMs was significantly correlated with brain abscess (11.5 vs. 6.2, respectively; p=0.025). The mean diameter of the largest feeding artery was significantly correlated with ischaemic stroke frequency (4.9 vs. 3.2 mm, respectively; p=0.0098).

CONCLUSIONS

The number of PAVMs correlated significantly with risk of brain abscess, and a larger feeding artery significantly with more ischaemic strokes. These findings can lead to a better recognition and management of the PAVMs at risk of cerebral complications.

KEY POINTS

• Chest CT helps clinicians to facilitate appropriate PAVM management strategies. • Pulmonary arteriovenous malformation CT findings are correlated with risk of cerebral complications. • Risk of brain abscess is significantly correlated with number of PAVMs. • Risk of ischaemic stroke is significantly correlated with large feeding artery PAVMs. • Prevalence of observed of brain abscess and ischaemic stroke is 26 %.

Transcatheter Repair of Congenital Heart Defects in the Young

In recent decades, tremendous medical advances have been made. Therapeutic cardiac catheterisation for repair of congenital heart defects has become the standard mode of therapy. Catheter techniques have progressed. They now provide temporary palliation, prepare the patient for surgical reconstruction, or offer a definitive repair. The main advantages of non-surgical procedures are avoidance of thoracotomy and cardiopulmonary bypass, together with a shorter hospitalisation period and speedier convalescence. Paediatric interventions include: transcatheter device closure of congenital cardiac defects, balloon angioplasty and valvuloplasty, atrial septostomy, patent ductus arteriosus stenting in the neonatal period, vessel embolisation, and many others. Topping those interventions is the introduction of transcatheter valve replacement. The aim of this article is to review these interventions and present them in a simplified, vibrant, and up-to-date fashion. In conclusion, paediatric cardiac interventions have established their reliability and ever-expanding scope in the setting of congenital heart disease management. Nevertheless, success is dependent on selecting the proper procedure for each condition, which may also vary with each patient. Thus, it is highly dependent on the experience and expertise of the operator. With the current rate of technological innovation, more and more surgical procedures will eventually be replaced by catheter-based interventions with a great degree of safety and efficacy.

Idiopathic pulmonary malformation: A case report

Background:

Pulmonary arteriovenous malformations have been associated with clinical situations that put life at risk or cause physical disability. When the clinical picture is evident, percutaneous occlusion is recommended.

Methods:

We describe the use of an Amplatzer vascular plug in a female patient for the treatment of an idiopathic pulmonary arteriovenous malformation associated with syncope and transient ischemic attacks.

Results:

The patient was successfully treated via percutaneous intervention without complications. At 6 months follow-up, there was an absence of the pulmonary arteriovenous malformation confirmed via angiotomography and a full reintegration into her daily activities with no-clinical eventualities.

Conclusion:

The use of an Amplatzer vascular plug should be considered for the treatment of idiopathic pulmonary arteriovenous malformation. In experienced centers the procedure can be done safely with excellent clinical outcomes.

Neurological involvement in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by epistaxis, telangiectases, and multi-organ vascular dysplasia. Head and neck localizations of HHT are recurrent, frequent associated with serious complications. The aim of this study was to describe the clinical and imaging patterns of neurological involvement in HHT and to discuss the role of interventional radiology in the management of HHT patients. Based on a multidisciplinary experience of twenty years at our center, we report here the different aspects of neurological involvement of HHT. Depending on the genetic type of the disease, vascular abnormalities may affect different organs. The knowledge of neurological involvement according to specific localization of HHT makes detection easier. As cerebral or spinal arteriovenous fistula may be present in patients with epistaxis or pulmonary arteriovenous malformations (PAVMs), radiologists should be able to detect high-risk lesions and prevent related complications. Finally, we review indications and techniques of embolization for hemorrhagic lesions and emphasize that endovascular therapies are very effective and safe in experienced hands. Head and neck imaging is commonly used for the diagnosis of HHT. Imaging plays also a key role for patient evaluation before treatment as pluridisciplinary management is needed.

[Embolization of pulmonary arteriovenous malformation causing hypoxemia in a 7-year-old child]

Pulmonary arteriovenous fistulas are abnormal vessels joining the right pulmonary artery to the pulmonary veins. They lead to an extracardiac right-to-left shunt with refractory hypoxemia. We report the case of a 7-year-old girl with a large pulmonary arteriovenous fistula discovered with refractory hypoxemia diagnosed during general anesthesia for adenoidectomy. Radio-opacity was observed on the upper lobe of the right lung. The diagnosis was made using thoracic angiotomography. The proximal arterial vessel arose from the lobar pulmonary artery. The fistula had developed in the entire right upper lobe and drained into two veins flowing into the right superior pulmonary artery. Given the marked hypoxemia, the potential risks of pulmonary hemorrhage and pulmonary infection, an occlusion of the fistula was indicated. After discussion between surgeons and interventional cardiologists, catheterization was indicated. The occlusion of the fistula was successful at the second attempt after release of a vascular plug in the main proximal vessel. This case illustrates the clinical circumstances of diagnosis of arteriovenous fistula, the diagnostic algorithm for refractory hypoxemia and the therapeutic options, with discussion of the benefits and drawbacks of a catheterization procedure.

Impact of pulmonary arteriovenous malformations on respiratory-related quality of life in patients with hereditary haemorrhagic telangiectasia

Fifteen to fifty percent of patients with hereditary haemorrhagic telangiectasia have pulmonary arteriovenous malformations. The objective of this study was to measure the effect of the presence of pulmonary arteriovenous malformations and of their embolisation on respiratory-related quality of life (QoL). We prospectively recruited patients with a diagnosis of hereditary haemorrhagic telangiectasia based on the Curaçao criteria and/or the identification of a pathogenic mutation. Respiratory-related quality of life was measured using the Saint George's Respiratory Questionnaire (SGRQ). Patients who underwent embolisation of pulmonary arteriovenous malformations completed the questionnaire before and 6-12 mo after the procedure. The 56 participants were divided into three groups: no pulmonary arteriovenous malformation (group A, n = 10), small pulmonary arteriovenous malformations not accessible to embolotherapy (group B, n = 19), and large pulmonary arteriovenous malformations accessible to embolotherapy (group C, n = 27). The SGRQ score was significantly higher in group C compared to the other groups, indicating a worse respiratory-specific QoL. There was no significant difference between groups A and B. Among the 17 patients who underwent an embolisation, the SGRQ score decreased significantly after the procedure, to a value similar to that in patients without pulmonary arteriovenous malformation. Our results indicate that the presence of large but not small pulmonary arteriovenous malformations negatively affects the respiratory-related quality of life and that embolisation of pulmonary arteriovenous malformations normalizes the respiratory-related quality of life.

Ischaemic stroke with intact atrial septum--exclude arteriovenous malformations

A 44-year-old woman was referred to our centre for interventional cardiac catheterisation. The diagnostic work-up after a preceding ischaemic stroke led to the assumption of a patent foramen ovale due to a positive bubble study. Before the planned percutaneous closure of the patent foramen ovale, we performed a second bubble study, which showed an intact atrial septum. However, after two to three heart cycles bubbles could be detected in the left atrium, assuming a right-to-left shunt of an extracardiac origin most likely in the lung. We therefore performed cardiac catheterisation, yielding a pulmonary arteriovenous malformation in the lower lobe of the right lung. This was successfully closed interventionally by placing a Cook coil, as well as several plugs into the malformation and feeding vessels.

Pulmonary arteriovenous malformations

Pulmonary arteriovenous malformations (PAVMs) are abnormal vascular structures that most often connect a pulmonary artery to a pulmonary vein, bypassing the normal pulmonary capillary bed and resulting in an intrapulmonary right-to-left shunt. As a consequence, patients with PAVM can have hypoxemia and paradoxical embolization complications, including stroke and brain abscess. PAVMs may be single or multiple, unilateral or bilateral, and simple or complex. Most PAVMs are hereditary and occur in hereditary hemorrhagic telangiectasia, an autosomal dominant vascular disorder, and screening for PAVM is indicated in this subgroup. PAVMs may also be idiopathic, occur as a result of trauma and infection, or be secondary to hepatopulmonary syndrome and bidirectional cavopulmonary shunting. Diagnostic testing involves identifying an intrapulmonary shunt, with the most sensitive test being transthoracic contrast echocardiography. Chest CT scan is useful in characterizing PAVM in patients with positive intrapulmonary shunting. Transcatheter embolotherapy is the treatment of choice for PAVM. Lifelong follow-up is important because recanalization and collateralization may occur after embolization therapy. Surgical resection is rarely necessary and reserved for patients who are not candidates for embolization. Antibiotic prophylaxis for procedures with a risk of bacteremia (eg, dental procedures) is recommended in all patients with PAVM because of the risk of cerebral abscess.

The use of US health insurance data for surveillance of rare disorders: hereditary hemorrhagic telangiectasia

PURPOSE

To assess the utility of US health insurance data for surveillance of hereditary hemorrhagic telangiectasia, an autosomal-dominant blood vasculature disorder with an estimated prevalence of 1.5-2.0 per 10,000 persons worldwide.

METHODS

We used 2005-2010 MarketScan Research Databases to identify individuals with employer-sponsored health insurance and International Classification of Disease, 9th Revision, Clinical Modification codes of 448.0 present in either one inpatient claim or two outpatient claims 30 days apart to define hereditary hemorrhagic telangiectasia. We examined frequencies of International Classification of Disease, 9th Revision, Clinical Modification codes for conditions that are complications of hereditary hemorrhagic telangiectasia among individuals with hereditary hemorrhagic telangiectasia and the general population to identify combinations of codes associated with hereditary hemorrhagic telangiectasia.

RESULTS

Excluding observations from one state, the average prevalence of hereditary hemorrhagic telangiectasia was 0.3 per 10,000 persons. The reported prevalence rose with age from ~0.1 per 10,000 at ages <30 years to 1.0-1.1 per 10,000 at ages 70 years and above. The condition codes that were most specific to presumed hereditary hemorrhagic telangiectasia were lung arteriovenous malformations and upper gastrointestinal angiodysplasia. Combinations of those codes and codes for brain arteriovenous malformation and epistaxis were highly predictive of reporting of hereditary hemorrhagic telangiectasia, with 20-57% of enrollees with those codes also meeting the study definition for hereditary hemorrhagic telangiectasia.

CONCLUSION

Hereditary hemorrhagic telangiectasia is underrecognized in US administrative data. Administrative health data can be used to identify individuals with combinations of signs that are suggestive of hereditary hemorrhagic telangiectasia. Studies are needed to test the hypothesis that referral for evaluation of individuals with administrative records suggestive of undiagnosed hereditary hemorrhagic telangiectasia could lead to diagnosis and access to life-saving treatments for both them and affected family members.

Contralateral decubitus positioning enhances computed tomographic angiographic evaluation of pulmonary vasculature in a patient with a pulmonary arteriovenous malformation

Computed tomographic pulmonary angiography has become the diagnostic procedure of choice in patients suspected of having a pulmonary embolus. However, intrapulmonary shunting of blood in a variety of pathologic conditions can cause suboptimal opacification of the pulmonary arterial circulation and result in a suboptimal or even nondiagnostic study. Radiologists should be aware of these conditions and be familiar with positioning techniques to minimize such shunting. We report a patient suspected of having pulmonary embolism, in whom a preexisting unilateral arteriovenous malformation prevented adequate evaluation of the pulmonary circulation. Positioning the patient in the contralateral decubitus position significantly enhanced image quality.

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

Pulmonary arteriovenous malformations (PAVMs) with feeding arteries of 3 mm or more have been shown to be associated with paradoxical embolization and serious neurologic complications. Therefore it is generally recommended to occlude feeding arteries of this size, while smaller feeding arteries often are left untreated. However, neurologic complications have also been described in patients with small PAVMs, and it has not been possible to stratify risk by size of feeding artery and thus there is no evidence that 3 mm is the critical size of the feeding artery potentially giving complications. Further, it is well-known that with time PAVMs and their feeding arteries may enlarge. Also, embolization of small feeding arteries will minimize the risk of paradoxical emboli and reduce the need for CT follow-up controls in these patients. Two cases demonstrate the possibility to embolize small feeding arteries.

[Isolated pulmonary arteriovenous malformation (PAVM)--report of three cases]

Isolated PAVM is rare condition and only a few cases of VATS (Video-Assisted Thoracoscopic Surgery) resection have been reported so far. Since the clinical course of PAVM is not entirely benign due to its possible progression and serious complications (paradoxical emboli, stroke, brain abscess, etc.), the most radical least invasive treatment should be chosen in all cases nowadays. Embolization may be incomplete and carries a risk of accidental systemic embolization, therefore surgical excision is the preferred method of choice. In cases of surgical resections, pulmonary parenchyma sparing techniques such as wedge resection and local excision by VATS is desirable, if possible. We present three patients who were admitted with asymptomatic pulmonary round shadow (umbra rotunda) for further investigation and treatment. We have performed two wedge resections by VATS and one segmentectomy via axillary thoracotomy. We wish to emphasize the importance of this disease to consider in differential diagnosis to avoid complications.