Reliability of contrast echocardiography to rule out pulmonary arteriovenous malformations and avoid CT irradiation in pediatric patients with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia - pediatric review

PURPOSE OF REVIEW

Hereditary hemorrhagic telangiectasia (HHT) diagnostic and management approach for pediatrics underwent significant advances over the last couple of years.

RECENT FINDINGS

In 2020, new guidelines for HHT were published that included a pediatric section thus attracting special focus into the childhood presentation.

SUMMARY

Curacao criteria are specific, but not sensitive enough in children. Genetic testing is encouraged for all family members even if asymptomatic. Standardized scoring for epistaxis is strongly encouraged, as it allows monitoring and can stratify therapeutic approaches. Early screening for pulmonary and brain visceral arteriovenous malformations (AVMs) in pediatric patients with confirmed genetic alterations of HHT should be instituted. Graded trans-esophageal echocardiogram with agitated saline contrast can be used as screening method for pulmonary AVMs. As pulmonary AVMs can develop throughout lifetime, guidelines recommend repeated screening even in asymptomatic patients at least every 5 years. Signs of stroke in childhood are more subtle than in adults. Cerebral imaging in early childhood can identify brain AVMs that may benefit from early intervention. Embolization of high-risk pulmonary and cerebral AVMs should be performed at specialized centers even at pediatric age. One or two classic HHT telangiectasia can be considered diagnostic in children. Antibiotic prophylaxis with dental procedures continues to be recommended.

ACR Appropriateness Criteria® Pulmonary Arteriovenous Malformation (PAVM): 2023 Update

Pulmonary arteriovenous malformations (PAVMs) occur in 30% to 50% of patients with hereditary hemorrhagic telangiectasia. Clinical presentations vary from asymptomatic disease to complications resulting from the right to left shunting of blood through the PAVM such as paradoxical stroke, brain abscesses, hypoxemia, and cardiac failure. Radiology plays an important role both in the diagnosis and treatment of PAVM. Based on different clinical scenarios, the appropriate imaging study has been reviewed and is presented in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Second International Guidelines for the Diagnosis and Management of Hereditary Hemorrhagic Telangiectasia

DESCRIPTION

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications.

METHODS

The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved.

RECOMMENDATIONS

The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.

Incidentally Identified Pulmonary AVM: An Unusual Cause for Stroke in a Young Patient

Pulmonary arteriovenous malformation is an uncommon though important potential source for embolic right-to-left extracardiac shunt as a cause for both silent and clinically evident stroke. We present this case to highlight this pathology as a cause for stroke, the importance of treating this malformation, even if incidentally identified, and finally the role of echocardiography in screening for extracardiac shunt and indicating those patients that may benefit from further investigations looking for extracardiac shunt.

Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct vascular communications between pulmonary arteries and veins which create high-flow right-to-left shunts. They are most frequently congenital, usually in the setting of hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with a wide variety of clinical manifestations such as dyspnea, hypoxemia, or chest pain. Even when asymptomatic, presence of PAVMs increases patients' risk of serious, potentially preventable complications including stroke or brain abscess. Transcatheter embolotherapy is considered the gold standard for treatment of PAVMs. Though previous guidelines have been published regarding the management of PAVMs, several aspects of PAVM screening and management remain debated among the experts, suggesting the need for thorough reexamination of the current literature. The authors of this review present an updated approach to the diagnostic workup and management of PAVMs, with an emphasis on areas of controversy, based on the latest literature and our institutional experience.

Growth of Pulmonary Arteriovenous Malformations in Pediatric Patients with Hereditary Hemorrhagic Telangiectasia

The evolution of pulmonary arteriovenous malformations (PAVMs) over time in children with hereditary hemorrhagic telangiectasia (HHT) is not well-defined. Herein we demonstrate that, although new PAVMs did not evolve in children with HHT, existing PAVMs exhibit quantitative growth over time highlighting the need for ongoing follow-up throughout childhood.

Comprehensive management of hereditary hemorrhagic telangiectasia

PURPOSE OF REVIEW

Hereditary hemorrhagic telangiectasia (HHT), or Osler Weber-Rendu disease, is a rare inherited disorder of fibrovascular tissue affecting various organs. Epistaxis is the most common symptom of HHT but as the disease affects multiple organs, a multisystem and multidisciplinary approach to management is required. The purpose of this article is to provide an overview of the multidisciplinary approach to HHT for the otolaryngologist and to discuss the current pharmacologic and procedural treatment options available for HHT-related epistaxis.

RECENT FINDINGS

Multidisciplinary expert guidelines have better defined what screening tests are advised for the multisystem evaluation of the HHT patient. New pharmacologic therapies including bevacizumab (Avastin) used submucosally or topically have shown promise as in-office treatment modalities. Sclerotherapy of telangiectasia, including in-office applications, has recently proven safe and effective.

SUMMARY

HHT remains a difficult disease to treat. Being aware of the common organ systems involved by the disease will help the practicing otolaryngologist to ensure the patient receives appropriate multidisciplinary care. For HHT-related epistaxis, new medical and surgical options allow for a wider range of treatments than were previously available.

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.

Pulmonary arteriovenous malformations in children with hereditary hemorrhagic telangiectasia: a longitudinal study

Pulmonary arteriovenous malformations (PAVMs) often occur in children with hereditary hemorrhagic telangiectasia (HHT). A 14-year longitudinal study of PAVMs in children with HHT was undertaken to assess the prevalence, the clinical impact, and progression of these malformations. This was a retrospective, single-center study from May 2002 to December 2016 of 129 children with HHT diagnosed using Curacao criteria and/or confirmed by genetic testing. Transthoracic contrast echocardiography (TTCE) was the primary screening modality in all patients and PAVMs were diagnosed based on Barzilai criteria. Moderately positive TTCE (Barzilai criteria ≥ 2) was confirmed with subsequent contrast chest CT. New PAVMs were diagnosed with a positive TTCE after an initial negative TTCE. Embolization of PAVMs were performed according to HHT consensus guidelines. Of 129 children with HHT, 76 (59%) were found to have PAVMs. Sixty-seven (88%) were positive for PAVMs on initial screening. Of 63 children without PAVMs on initial screening, 31 were followed for >1 year. Nine of the 31 (29%) developed new PAVMs after initial negative study. Thirty-eight (50%) of the total 76 children with PAVMs had or developed lesions large enough to be treated with embolization. Nine patients with PAVMs initially too small to be treated with embolization, developed progression of disease and ultimately were treated with embolization over time. The majority, 60% (23/38), of the children with large PAVMs had no related clinical symptoms. After embolization, 21% (8/38), of patients underwent repeat interventions. Genetic diagnosis, age, and gender were not associated with risk of having PAVM nor with need for repeat interventions. Nearly 60% of children with HHT develop PAVMs. The risk for new PAVMs to develop, small PAVMs to become large, and previously embolized PAVMs to require further intervention remains throughout childhood. Thus, children with HHT require continued follow-up until adulthood.

Echocardiography Grading for Pulmonary Arteriovenous Malformation Screening in Children with Hereditary Hemorrhagic Telangiectasia

Transthoracic contrast echocardiography (TTCE) has high sensitivity but low specificity in screening for pulmonary arteriovenous malformations (pAVMs) in children with hereditary hemorrhagic telangiectasia (HHT). Here we describe characteristics of TTCE that might be used to reduce the need for confirmatory computed tomography scans in children with HHT.

Screening children for pulmonary arteriovenous malformations: Evaluation of 18 years of experience

BACKGROUND

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disease with multi-systemic vascular dysplasia. Early diagnosis through screening is important to prevent serious complications. How best to screen children of affected parents for pulmonary arteriovenous malformations (PAVMs) is often subject to debate. Transthoracic contrast echocardiogram (TTCE) is considered optimal in screening for PAVMs in adults. Guidelines for the screening of children are not specific, reflecting the lack of scientific evidence on the best method to use.

OBJECTIVE

Aims of this study are (i) to evaluate our current screening method, consisting of history, physical examination, pulse oximetry, and chest radiography and (ii) to assess whether postponing more invasive screening for PAVMs until adulthood is safe.

METHODS

This is a prospective observational cohort study using a patient database.

RESULTS

Over a period of 18 years (mean follow-up 9.21 years, SD 4.72 years), 436 children from HHT families were screened consecutively. A total of 175/436 (40%) children had a diagnosis of HHT. PAVMs were detected in 39/175 (22%) children, 33/39 requiring treatment by embolotherapy. None of the screened children suffered any PAVM-associated complications with this screening method.

CONCLUSION

This study shows that a conservative screening method during childhood is sufficient to detect large PAVMs and protect children with HHT for PAVM-related complications. Postponing TTCE and subsequent chest CT scanning until adulthood to detect any smaller PAVMs does not appear to be associated with major risk.

Non-invasive CT screening for pulmonary arteriovenous malformations in children with confirmed hereditary hemorrhagic telangiectasia: Results from two pediatric centers

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder that is caused by mutations in mainly two genes, that is ENG, encoding endoglin (HHT1), or ACVRL1, encoding activin receptor-like kinase 1 (ALK-1/HHT2). HHT is characterized by recurrent epistaxis, mucocutaneous telangiectasia, and vascular visceral dysplasia responsible for visceral arteriovenous malformations (AVM).

AIM

to report the experience of two university hospitals (Trousseau, Paris, and CHIC, Creteil) with screening children for HHT and pulmonary AVM (PAVM) using high resolution computed tomography (HRCT).

METHODS

parents with confirmed HHT were offered to have their children screened for the mutation identified in their family, and informed consent was obtained. Children carrying the same mutation as their parents underwent HRCT of the chest without contrast.

RESULTS

between 2008 and 2015, 99 children were screened for HHT mutations. Mutations were identified in 59 patients, that is 24 HHT1 and 35 HHT2. Radiologic and clinical screening was possible in 52 patients (21 HHT-1 and 31 HHT-2). Among those, PAVM was identified in 13 patients (25%; n = 8 HHT1; n = 5 HHT2), and four of them required embolization therapy.

CONCLUSION

This study highlights the usefulness of genetic screening in children with known HHT family. It also suggests that a non-invasive protocol such as HRTC is an efficient approach to detect non-symptomatic lesions that are present early on in children carrying the ENG (HHT1), but also the ACVRL1 mutations (HHT2). Pediatr Pulmonol. 2017;52:642-649. © 2017 Wiley Periodicals, Inc.