A systematic review supporting the Society for Vascular Surgery guidelines on the management of heritable aortopathies

BACKGROUND

To support the development of clinical practice guidelines on the management of patients with genetic aortopathies and arteriopathies, a writing committee from the Society for Vascular Surgery has commissioned this systematic review.

METHODS

We conducted a systematic review and searched multiple databases for studies addressing six questions identified by the Society for Vascular Surgery guideline committee about evaluating and managing patients with genetic aortopathies and arteriopathies. Studies were selected and appraised by pairs of independent reviewers.

RESULTS

We included 12 studies in this systematic review. We did not identify studies about the long-term outcomes of endovascular repair for aortic aneurysm in patients with heritable aortopathy or about new aortic events in pregnant women with a history of aortic dissection (AD) or aneurysm. A small case series demonstrated a 100% survival rate and 100% aortic intervention-free survival at 15 months (range, 7-28 months) after endograft repair for type B AD. A positive genetic diagnosis was discovered in 36% of patients with aortic aneurysms and dissections who had no risk factors for hereditary aortopathies, and these patients had a mortality rate of 11% at a median follow-up duration of 5 months. Black patients had lower 30-day mortality than White patients (5.6% vs 9.0%, respectively), but they had a higher overall aortic reintervention rate at 30 days after AD repair (47% vs 27%, respectively). Aortic reinterventions owing to aneurysmal expansion and endoleak at 30 days were higher in Black patients than White patients. The certainty of evidence was judged to be very low across all the outcomes evaluated in this systematic review.

CONCLUSIONS

The available evidence suggests high survival after thoracic endovascular aortic repair for type B AD in young patients with heritable aortopathies, but with limited long-term follow-up. Genetic testing in patients with acute aortic aneurysms and dissections had a high yield. It was positive for most patients with risk factors for hereditary aortopathies and in more than one-third for all other patients, and was associated with new aortic events within 15 years.

Clinical features and complications of Loeys-Dietz syndrome: A systematic review

INTRODUCTION

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that arises from mutations altering the transforming growth factor β signalling pathway. Due to the recent discovery of the underlying genetic mutations leading to LDS, the spectrum of characteristics and complications is not fully understood.

METHODS

Our search included five databases (Pubmed, SCOPUS, Web of Science, EMBASE and google scholar) and included variations of "Loeys-Dietz Syndrome" as search terms, using all available data until February 2021. All study types were included. Three reviewers screened 1394 abstracts, of which 418 underwent full-text review and 392 were included in the final analysis.

RESULTS

We identified 3896 reported cases of LDS with the most commonly reported features and complications being: aortic aneurysms and dissections, arterial tortuosity, high arched palate, abnormal uvula and hypertelorism. LDS Types 1 and 2 share many clinical features, LDS Type 2 appears to have a more aggressive aortic disease. LDS Type 3 demonstrated an increased prevalence of mitral valve prolapse and arthritis. LDS Type 4 and 5 demonstrated a lower prevalence of musculoskeletal and cardiovascular involvement. Amongst 222 women who underwent 522 pregnancies, 4% experienced an aortic dissection and the peripartum mortality rate was 1%.

CONCLUSION

We observed that LDS is a multisystem connective tissue disorder that is associated with a high burden of complications, requiring a multidisciplinary approach. Ongoing attempts to better characterise these features will allow clinicians to appropriately screen and manage these complications.

Reinterventions and new aortic events after aortic surgery in Marfan syndrome

OBJECTIVES

Pre-emptive strategies to manage the aortic complications of Marfan syndrome have resulted in improved life expectancy yet, secondary to the variation of phenotypic expression, anticipating the risk and nature of future aortic events is challenging. We examine rates of new aortic events and reinterventions in a Marfan cohort following initial aortic presentation.

METHODS

Retrospective cohort study of Marfan patients with aortic pathology presenting to our institution 1998-2018. Patients were grouped according to index event: aortic dissection or root aneurysm. Patients with aortic dissection were classified according to Debakey criteria. Incidence of new aortic events and frequency of reintervention were analysed.

RESULTS

One hundred and twenty-six aortic procedures were performed in 74 Marfan patients with a median follow-up of 7 years. Forty-seven patients had an index event of root aneurysm and 27 had aortic dissection. Following operative intervention in the aneurysm group, 7 patients developed Debakey III dissections raising the overall number of patients who developed dissection within this cohort to 34. Reinterventions were more frequent in the dissection group with full replacement of the native aorta in 5 patients.

CONCLUSIONS

After operative intervention on the proximal aorta, a proportion will develop distal pathology. A greater focus on factors contributing to future events, such as mapping genotypes to clinical course, may lead the way for targeted operative techniques and surveillance.

Genetic profiling and cardiovascular phenotypic spectrum in a Chinese cohort of Loeys-Dietz syndrome patients

Background

Loeys-Dietz syndrome (LDS) is a rare connective tissue disorder for which 6 genes in the TGF-β pathway have been identified as causative. With the widespread use of genetic testing, the range of known clinical and genetic profiles has broadened, but these features have not been fully elucidated thus far.

Methods and results

Using gene panel sequencing or whole exome sequencing, we identified 54 unique rare variants in LDS genes in 57 patients with thoracic aneurysms/dissections, including 27 pathogenic mutations (P + LP) and 27 variants of unknown significance (VUS^LP + VUS). Genotype-phenotype correlation analysis revealed that carriers with P/LP/ VUS^LP variants in TGFBR1/TGFBR2/SMAD3 genes had significantly more severe cardiovascular features (cardiovascular death/dissection) than carriers with VUSs in these 3 genes at an early age and had less favorable event-free survival. Additionally, carriers with VUS in combination with other risk factors, such as hypertension, might be prone to developing an aortic dissection, as indicated by the fact that 5/8 (62.5%) patients with VUSs in our cohort developed aortic dissections in the presence of hypertension, compared with 25.0% (3/12) in the absence of hypertension (p = 0.047).

Conclusions

To date, this was the largest cohort of LDS patients ever reported in China, and the present study expanded the known mutation and phenotypic spectra of LDS, which might help refine our knowledge of LDS.

Cardiovascular surgery in Loeys-Dietz syndrome types 1-4

OBJECTIVES

The first publication of Loeys-Dietz syndrome (LDS) described aortic rupture at young ages. Experience with new LDS types showed that the clinical course varies, and thresholds for prophylactic surgery are discussed. As this is an uncommon disease, experience needs to be shared.

METHODS

Retrospective review of patients with LDS types 1-4 undergoing cardiovascular surgery during the years 1991-2016.

RESULTS

Thirty-five patients (including 6 children with LDS2) underwent 57 operations. LDS 1, 2, 3 and 4 included 4, 17, 11 and 3 patients, respectively. Mean age at first surgery was 36 years, with a non-significant trend that LDS2 patients were younger. Of the 9 emergency surgeries, 7 were type A dissections, with 1 postoperative death. Twenty-two patients had prophylactic aortic root surgery (17 valve-sparing root replacements), with 1 postoperative death, 1 reoperation with valve replacement and 1 late death. Freedom from root reintervention and death was 92% at 13 years. Of the 11 patients with LDS3, 5 needed mitral valve surgery. Mitral valve disease was not found in the other LDS types. Ten patients needed >1 operation. Of the 57 operations, 33 were in the ascending aorta, 20 in the aorta distal to the arch including branches and 4 were isolated heart surgeries. Of the 20 vascular operations, 16 were in LDS2. Cumulative survival 20 years after first surgery (all patients) was 94.3%.

CONCLUSIONS

Clinical course seems to be more aggressive in LDS2, with index operation at a younger age, and higher risk of needing several operations. Vascular disease distal to the arch is not uncommon. LDS3 seems to be associated with mitral valve disease. Prophylactic aortic root surgery is safe and durable.

Re-interventions on the thoracic and thoracoabdominal aorta in patients with Marfan syndrome

The advent of multi-gene panel genetic testing and the discovery of new syndromic and non-syndromic forms of connective tissue disorders have established thoracic aortic aneurysms as a genetically mediated disease. Surgical results in patients with Marfan syndrome (MFS) provide an important benchmark for this patient population. Prophylactic aortic root surgery prevents acute dissection and has contributed to the improved survival of MFS patients. In the majority of patients, re-interventions are driven by a history of dissection. Patients undergoing elective root repair have a low risk for re-interventions on the root itself. Experienced centers have results after valve-sparing procedures at 10 years comparable with those seen after a modified Bentall procedure. In patients where only the ascending aorta was replaced during the initial surgery, re-intervention rates are high as the root continues to dilate. The fate of the aortic arch in MFS patients presenting with dissection is strongly correlated with the extent of the initial surgery. Not replacing the entire ascending aorta and proximal aortic arch results in a high rate of re-interventions. Nevertheless, the additional burden of replacing the entire aortic arch during emergent proximal repair is not very well defined and makes comparisons with patients undergoing elective arch replacement difficult. Interestingly, replacing the entire aortic arch during initial surgery for acute dissection does not protect from re-interventions on downstream aortic segments. MFS patients suffering from type B dissection have a high risk for re-interventions ultimately leading up to replacement of the entire thoracoabdominal aorta even if the dissection was deemed uncomplicated by conventional criteria. While current guidelines do not recommend the implantation of stent grafts in MFS patients, implantation of a frozen-elephant-trunk to create a stable proximal landing zone for future endovascular or open procedures has emerged as a means to address aortic arch and descending aortic pathologies.

Genetic testing of 10 patients with features of Loeys-Dietz syndrome

Inherited aortopathy, characterized with a high risk of fetal aortic aneurysms/dissections, could occur secondary to several syndromes. To identify genetic mutations and help to give a precise diagnosis, we performed a gene panel testing, involving 15 genes related to inherited aortopathy. Here we reported 10 patients, combining with the genetic testing results, were diagnosed or suspected with Loeys-Dietz syndrome, which would be the largest group of Loeys-Dietz syndrome ever reported in China till now. 10 likely pathogenic mutations or rare variants of uncertain significance were found. These results expanded the mutation spectrum of Loeys-Dietz syndrome and might be implicated in its wide phenotypic spectrum.