The effects of nasal closure on quality of life in patients with hereditary hemorrhagic telangiectasia

Evaluation of AAV Capsids and Delivery Approaches for Hereditary Hemorrhagic Telangiectasia Gene Therapy

Nosebleeds and intracranial hemorrhage from brain arteriovenous malformations (bAVMs) are among the most devastating symptoms of patients with hereditary hemorrhagic telangiectasis (HHT). All available managements have limitations. We showed that intravenous (i.v.) delivery of soluble Feline McDonough Sarcoma (FMS)-related tyrosine kinase 1 using an adeno-associated viral vector (AAV9-sFLT1) reduced bAVM severity of endoglin deficient mice. However, minor liver inflammation and growth arrest in young mice were observed. To identify AAV variants and delivery methods that can best transduce brain and nasal tissue with an optimal transduction profile, we compared 3 engineered AAV capsids (AAV.cc47, AAV.cc84, and AAV1RX) with AAV9. A single-stranded CBA promoter driven tdTomato transgene was packaged in these capsids and delivered i.v. or intranasally (i.n.) to wild-type mice. A CMV promoter driven Alk1 transgene was packaged into AAV.cc84 and delivered to PdgfbiCre;Alk1f/f mice through i.v. followed by bAVM induction. Transduced cells in organs, vessel density, abnormal vessels in the bAVMs, and liver inflammation were analyzed histologically. Liver and kidney function were measured enzymatically. Compared to other viral vectors, AAV.cc84, after i.v. delivery, transduced a high percentage of brain endothelial cells (ECs) and few hepatocytes; whereas after i.n. delivery, AAV.cc84 transduced ECs and perivascular cells in the brain, and ECs, epithelial cells, and muscles in the nose with minimum hepatocyte transduction. No changes to liver or kidney function were detected. The delivery of AAV.cc84-Alk1 through i.v. to PdgfbiCre;Alk1f/f mice reduced bAVM severity. In summary, we propose that AAV.cc84-Alk1 is a promising candidate for developing gene therapy in HHT patients.

Evaluation of Aav Capsids and Delivery Approaches for Hereditary Hemorrhagic Telangiectasia Gene Therapy

Nosebleeds and intracranial hemorrhage from brain arteriovenous malformations (bAVMs) are among the most devastating symptoms of patients with hereditary hemorrhagic telangiectasis (HHT). All available managements have limitations. We showed that intravenous delivery of soluble FMS-related tyrosine kinase 1 using an adeno-associated viral vector (AAV9-sFLT1) reduced bAVM severity of endoglin deficient mice. However, minor liver inflammation and growth arrest in young mice were observed. To identify AAV variants and delivery methods that can best transduce brain and nasal tissue with an optimal transduction profile, we compared 3 engineered AAV capsids (AAV.cc47, AAV.cc84 and AAV1RX) with AAV9. A single-stranded CBA promoter driven tdTomato transgene was packaged in these capsids and delivered intravenously (i.v.) or intranasally (i.n.) to wild-type mice. A CMV promoter driven Alk1 transgene was packaged into AAV.cc84 and delivered to PdgfbiCre;Alk1 f/f mice through i.v. injection followed by brain AVM induction. Transduced cells in different organs, vessel density and abnormal vessels in the bAVMs, and liver inflammation were analyzed histologically. Liver and kidney function were measured enzymatically. Compared to other viral vectors, AAV.cc84, after i.v. delivery, transduced a high percentage of brain ECs and few hepatocytes; whereas after i.n. delivery, AAV.cc84 transduced ECs and perivascular cells in the brain, and ECs, epithelial cells, and skeletal muscles in the nose with minimum hepatocyte transduction. No changes to liver or kidney function were detected. Delivery of AAV.cc84-Alk1 through i.v. to PdgfbiCre;Alk1 f/f mice reduced bAVM severity. In summary, we propose that AAV.cc84-Alk1 is a promising candidate for developing gene therapy in HHT patients.

Understanding hereditary hemorrhagic telangiectasia: From genetic anomalies to systemic manifestations, quality of life, and epistaxis management-Exploring the otolaryngologist's integral role

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Rendu-Weber syndrome, is a rare autosomal dominant disorder characterized by vascular malformations. This comprehensive review aimed to provide an overview and summarize various aspects of HHT, including the genetic abnormalities, complications associated with visceral arteriovenous malformations (AVMs), prognosis of HHT, quality of life (QOL), and treatment of epistaxis. In addition, this review highlights the challenges in diagnosing HHT and emphasizes the critical role of otolaryngologists in the early detection of HHT. Otolaryngologists can refer patients with refractory epistaxis for AVM screening to expedite intervention. Mutation of the genes involved in the transforming growth factor-β signaling pathway leads to the incidence of HHT, resulting in the formation of abnormal blood vessel formation. These vascular malformations commonly manifest as telangiectasia on the skin and mucous membranes; however, epistaxis remains the hallmark symptom of HHT. The impact of HHT goes beyond the visible symptoms and often includes the formation of life-threatening visceral AVMs in the lungs, liver, and brain. The prognosis of patients with HHT is closely related to the development of these complications, necessitating timely diagnosis and intervention. Refractory epistaxis diminishes the QOL of patients with HHT. The management of epistaxis ranges from conservative measures to advanced interventions such as prevention, conservative treatments, ablation, surgical procedures, and the administration of anti-angiogenic agents. However, effective management requires a multidisciplinary approach. The diagnosis of HHT remains challenging due to its variable presentation and lack of awareness among physicians. This review highlights the importance of reducing the duration between symptom onset and diagnosis. Otolaryngologists who are experienced in the management of refractory epistaxis can aid in identifying potential cases of HHT. They can facilitate the initiation of screening for visceral AVMs via prompt recognition of the signs and symptoms of HHT, contributing to improved patient outcomes. Early detection and intervention through screening can extend the life expectancy of patients with HHT to levels comparable with that of the general population. In conclusion, this review provides insight into various aspects of HHT and emphasizes the importance of timely diagnosis and intervention in the mitigation of the potentially life-threatening complications associated with this disorder. Otolaryngologists play a critical role in this process, serving as gatekeepers to the identification of cases of HHT and implementation of appropriate screening and management pathways, thereby improving the life expectancy and QOL of patients.

Health-Related Quality of Life Outcome Measures in Individuals With Hereditary Hemorrhagic Telangiectasia: A Scoping Review

BACKGROUND

Studies evaluating health-related quality of life (HRQOL) in patients with hereditary hemorrhagic telangiectasia (HHT) have expanded rapidly in the past decade. These studies have evaluated QOL aspects ranging from the general QOL for patients living with HHT to intervention-specific outcomes. However, few tools have been fully validated across the spectrum of disease manifestations and interventions in HHT.

OBJECTIVE

In this scoping review, we aim to map the literature on HHT-QOL metrics, identify gaps, inform future QOL research, and facilitate future metric development.

METHODS

We analyzed articles in English that assessed at least 1 measure of general HRQOL, including physical health, mental health, social health, or intervention-specific QOL in patients with HHT. Searches across 2 bibliographic databases (PubMed and Scopus) yielded 186 articles after duplicates were removed. Sixty-three studies met eligibility criteria: 22 prospective studies (34.9%), 20 retrospective studies (31.7%), 12 cross-sectional studies (17.5%), 6 randomized controlled trials or secondary analyses of a randomized controlled trials (9.5%), 2 qualitative studies (3.2%), and 1 case-control study (1.6%). Two additional studies-1 prospective and 1 cross-sectional study-were identified at the October 2022 14th International HHT Conference and included, making a total of 65 studies.

RESULTS

The 65 eligible studies used 30 QOL instruments. Twenty studies characterized baseline HRQOL, and 45 studies evaluated QOL before and after treatment. Of those 45 studies, 37 evaluated HRQOL before and after therapies targeting epistaxis and nasal symptoms, 4 targeted therapies for liver arteriovenous malformations and high-output heart failure, 3 evaluated therapies for both epistaxis and gastrointestinal bleeding, and 1 evaluated treatment targeting gastrointestinal bleeding alone.

CONCLUSIONS

Comparison of results across studies remains challenging given the heterogeneity in outcomes measures. Further development of HHT-specific patient-reported outcomes instruments that capture the global illness experience of HHT is needed.

Surgiflo® hemostatic matrix versus NasoPore® nasal packing following postassium titanyl phosphate laser surgery for hereditary hemorrhagic telangiectasia: A randomized controlled trial

Background

To help ensure adequate hemostasis immediately following potassium titanyl phosphate (KTP) laser treatment, many centres treating hereditary hemorrhagic telangiectasia (HHT) routinely use nasal packing post-operatively. The purpose of this study was to compare hemostatic thrombin matrix with standard packing for postoperative bleeding, patient pain, and comfort.

Methods

A prospective, randomized, double-blinded, non-inferiority study was conducted with participants at an HHT centre of excellence (COE) and randomized to the treatment group with reconstituted thrombin gelatin matrix (Surgiflo®) or control group with a biodegradable synthetic polyurethane foam (NasoPore®). Adult subjects with confirmed HHT and moderate to severe epistaxis (a minimum calculated epistaxis severity score [ESS] of 4.0) warranting KTP laser treatment were recruited. Data was collected 2 weeks post operatively by a blinded reviewer completing a visual outcomes evaluation and each patient completing a subjective symptoms questionnaire. Non-parametric statistical analysis was employed.

Results

Twenty-eight adult patients were randomized to the treatment and control arms with comparable preoperative epistaxis severity scores. Postoperative nasal bleeding was equivalent. Significantly less pain was found in the treatment arm (p = .005). While there were trends towards less obstruction and increased satisfaction in the treatment group as well as less crusting in the control group, these findings were not statistically significant. Allocation to the treatment group was associated with an approximately $75 higher cost.

Conclusions

When compared to NasoPore® for hemostasis, Surgiflo® hemostatic matrix performed equivalently while causing less discomfort in HHT patients following nasal KTP treatment.

Level of evidence

1b.

Long-term efficacy assessment of current treatment options for epistaxis in HHT

Purpose

Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder that presents with recurrent, intractable epistaxis. The aim of this study was to retrospectively analyze the efficacy of various treatment options for epistaxis in patients with HHT, over a period of 18 years, and to correlate these findings with available evidence in the literature.

Methods

Records of patients with HHT, treated for epistaxis between 2000 and 2018 were analyzed. Treatment procedures carried out and their efficacy were extracted and analyzed.

Results

Forty-three records were evaluated. All patients were given nasal humidifying ointments, 93% required acute treatment with bipolar electrocautery, and 60% underwent atraumatic nasal packing. Recurrent cases were treated medically with tranexamic acid (26%), oestrogen (19%), and bevacizumab (2%). Laser photocoagulation was done in selected cases (40%) and if unsuccessful, septal dermoplasty was performed (2.3%). Endovascular embolization was reserved for life-threatening emergencies (7%).

Conclusion

Epistaxis in HHT is not curable, but can be managed by employing a comprehensive stepwise approach. An algorithm for effective and comprehensive management has been presented.

Effects of tranexamic acid on human nasal ciliary beat frequency

Background

Patients with recurrent epistaxis, particularly due to hereditary hemorrhagic telangiectasia (HHT) are recommended to apply topical tranexamic acid (TXA) to reduce bleeding events. Those patients may suffer ciliary dysfunction due to TXA’s effects on ciliary beating frequency (CBF) and their consequences.

Methodology/principal

Human nasal epithelial cells were harvested with a nasal brush in 30 healthy subjects. We investigated the CBF in RPMI medium using high-frequency video microscopy. TXA was added to the cells in various concentrations ranging from 2 to 5%, including the therapeutic concentration (2%) and a control (0%).

Results

CBF in the control condition was 6.1 ± 1.6 Hz. TXA reduces CBF in a time and concentration dependent manner, to, e.g. 4.3 ± 1.2 Hz with 2% TXA and 3.3 ± 0.9 Hz with 5% TXA after 16–20 min. The differences in CBF were statistically significant for all concentrations of TXA.

Conclusions

TXA has the potential to significantly impair nasal epithelial function. Therefore, frequent or regular topical nasal application of TXA should be done under close monitoring of nasal function, especially in patients with co-morbidities like chronic rhinosinusitis.

Patient-recorded benefit from nasal closure in a Danish cohort of patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Nasal closure, also known as the modified Young's procedure was introduced in Denmark in 2008, as a surgical solution to severe epistaxis in patients with hereditary haemorrhagic telangiectasia (HHT). The objective of this study was to report the overall satisfaction of the procedure from a patient's point of view as well as the occurrence of complications.

METHODS

All the HHT patients who underwent nasal closure from 2008 to 2018 were included in the study. The patients were evaluated for postoperative complications and subjective outcome using Glasgow Benefit Inventory (GBI).

RESULTS

Ten patients were included in the study and were observed for a mean of 64 months. None of the patients was completely free of complications, and reversal was requested in a single case. Haemoglobin levels rose with an average of 2.8 g/dl. The average GBI score after surgery was 38.05. Nine of ten patients would recommend nasal closure to fellow HHT patients.

CONCLUSION

Nasal closure is highly recommended among patients, but due to the rate of postoperative complications, the procedure should be reserved for a carefully selected group of HHT patients.

Severe Recurrent Epistaxis - The Main Symptom of Hereditary Haemorrhagic Teleangiectasia

Hereditary haemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is of dominant autosomal inheritance. Pathologic changes of vascular walls cause recurrent episodes of bleeding from many organ systems. Recurrent epistaxis is the first and the most frequent symptom of HHT. The causal therapy is not known but there are many therapeutic procedures improving the overall condition.

We present a case of a 76-year-old man suffering from HHT, frequently hospitalized and treated for massive nose bleeding. In past a selective arterial embolization was performed thrice; nonetheless, the intensity and frequency of epistaxis remained unchanged. Anterior nasal package and electrocoagulation were performed repeatedly as the “first aid” treatment. In the article we also mention other therapeutic modalities for this diagnosis; unfortunately, their efficacy remains inadequate.