Successful endovascular repair of acute type B aortic dissection in undiagnosed Ehlers-Danlos syndrome type IV

Multidisciplinary hybrid approach to management of a thoracoabdominal aneurysm in a patient with both Loeys-Dietz and vascular Ehlers-Danlos syndrome

Loeys-Dietz syndrome and vascular Ehlers-Danlos syndrome are genetic aortopathies that result from abnormal collagen matrix formation associated with vascular complications and early death. Identification of simultaneous COL3A1 and SMAD3 mutations as well as subsequent open and endovascular repair have not been reported. We present a case of a staged complete aortic replacement in a patient with a 7-cm aneurysm of his aortic arch and confirmed genetic mutations for Loeys-Dietz syndrome and vascular Ehlers-Danlos syndrome. This case highlights that, despite increased operative risk, successful staged repair of the entire aorta can be achieved in a patient with multiple severe genetic aortopathies.

Complicated Open Repair of Type B Aortic Dissection in a Patient With Ehlers-Danlos Syndrome Rescued by Endovascular Intervention

Ehlers-Danlos is a connective tissue disorder characterized by hypermobile joints, hyperextensible skin, and increased bleeding tendency. We report a case involving endovascular repair of an intussusception of aortic dissection that occurred in an Ehlers-Danlos patient following surgical repair of an intercostal artery bleed. Given the rarity of Ehlers-Danlos, continued reporting of treatment outcomes is important for refining complication management in this population. Our experience lends support for endovascular rescue of failed aortic repair that may arise in Ehlers-Danlos patients and contributes to the otherwise small body of literature concerning endovascular intervention in this population overall.

Outcomes of Thoracic Endovascular Aneurysm Repair (TEVAR) in Patients With Connective Tissue Disorders

Objectives:

Thoracic endovascular aortic repair (TEVAR) remains controversial in patients with connective tissue disorders given the concern for durability. We report on the largest series to date on outcomes of patients with thoracic aortic disease and connective tissue disorders treated with TEVAR.

Methods:

The Vascular Quality Initiative registry identified 12 207 patients treated with TEVAR from January 2010 to December 2018, including 102 with Marfans, Ehlers-Danlos, or Loey-Dietz syndrome. Outcomes were analyzed per the Society for Vascular Surgery reporting standards.

Results:

Median age was 50.6 years (interquartile range: 57.0-75.0), and 62 (60.7%) were male. Eighty-eight (86.3%) patients had Marfan, 9 (8.8%) had Ehlers-Danlos, and 5 (4.9%) had Loey-Dietz syndrome. Twenty-six (25.5%) patients were treated for degenerative aneurysmal disease and 76 (74.5%) patients for type B dissections (33 acute, 31 chronic). Most common indications for interventions in patients with type B dissection were pain (n = 41), aneurysmal degeneration (n = 16), and malperfusion (n = 8), with 3 patients who presented ruptured. There was no significant difference in perioperative complications between acute/chronic dissections and aneurysms ( P = .14). Percutaneous access was utilized in 61.7% of patients, with a 2.9% rate of arterial injury requiring reintervention. Follow-up data were available for 75 (73.3%) patients at a mean follow-up of 15.6 months. Overall mortality was 5.3%. There were 30 patients with follow-up endoleak data, and 8 (26.7%) endoleaks were identified. All endoleaks were in patients treated for acute type B dissection, and all resolved after a mean of 2.1 reinterventions. Three patients treated for acute Type B Aortic Dissection (TBAD) had retrograde dissections requiring intervention.

Discussion:

Thoracic endovascular aortic repair for patients with connective tissue disorders can be performed with low perioperative mortality, spinal cord ischemia, or Cerebrovascular Accident (CVA). On follow-up, acute type B aortic dissections represent a higher risk subgroup with increased rates of endoleak and retrograde dissection. Closer follow-up for these patients and early reintervention may be beneficial.

A multi-institutional experience in the aortic and arterial pathology in individuals with genetically confirmed vascular Ehlers-Danlos syndrome

OBJECTIVE

Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder owing to pathogenic variants in COL3A1 that lead to impaired type III collagen production. We aim to describe the contemporary multi-institutional experience of aortic and arterial pathology in individuals with vEDS, to evaluate disease patterns and refine management recommendations.

METHODS

This cross-sectional, retrospective study of individuals with genetically confirmed vEDS was conducted between 2000 and 2015 at multiple institutions participating in the Vascular Low Frequency Disease Consortium. Aortic and arterial events including aneurysms, pseudoaneurysms, dissections, fistulae, or ruptures were studied. Demographics, COL3A1 variants, management, and outcomes data were collected and analyzed. Individuals with and without arterial events were compared.

RESULTS

Eleven institutions identified 86 individuals with pathogenic variants in COL3A1 (47.7% male, 86% Caucasian; median age, 41 years; interquartile range [IQR], 31.0-49.5 years; 65.1% missense COL3A1 variants). The median follow-up from the time of vEDS diagnosis was 7.5 years (IQR, 3.5-12.0 years). A total of 139 aortic/arterial pathologies were diagnosed in 53 individuals (61.6%; 50.9% male; 88.5% Caucasian; median age, 33 years; IQR, 25.0-42.3 years). The aortic/arterial events presented as an emergency in 52 cases (37.4%). The most commonly affected arteries were the mesenteric arteries (31.7%), followed by cerebrovascular (16.5%), iliac (16.5%), and renal arteries (12.2%). The most common management was medical management. When undertaken, the predominant endovascular interventions were arterial embolization of medium sized arteries (13.4%), followed by stenting (2.5%). Aortic pathology was noted in 17 individuals (32%; 58.8% male; 94.1% Caucasian; median age, 38.5 years; IQR, 30.8-44.7 years). Most notably, four individuals underwent successful abdominal aortic aneurysm repair with excellent results on follow-up. Individuals with missense mutations, in which glycine was substituted with a large amino acid, had an earlier onset of aortic/arterial pathology (median age, 30 years; IQR, 23.5-37 years) compared with the other pathogenic COL3A1 variants (median age, 36 years; IQR, 29.5-44.8 years; P = .065). There were 12 deaths (22.6%) at a median age of 36 years (IQR, 28-51 years).

CONCLUSIONS

Most of the vEDS arterial manifestations were managed medically in this cohort. When intervention is required for an enlarging aneurysm or rupture, embolization, and less frequently stenting, seem to be well-tolerated. Open repair of abdominal aortic aneurysm seems to be as well-tolerated as in those without vEDS; vEDS should not be a deterrent to offering an operation. Future work to elucidate the role of surgical interventions and refine management recommendations in the context of patient centered outcomes is warranted.

Results of next-generation sequencing gene panel diagnostics including copy-number variation analysis in 810 patients suspected of heritable thoracic aortic disorders

Simultaneous analysis of multiple genes using next-generation sequencing (NGS) technology has become widely available. Copy-number variations (CNVs) in disease-associated genes have emerged as a cause for several hereditary disorders. CNVs are, however, not routinely detected using NGS analysis. The aim of this study was to assess the diagnostic yield and the prevalence of CNVs using our panel of Hereditary Thoracic Aortic Disease (H-TAD)-associated genes. Eight hundred ten patients suspected of H-TAD were analyzed by targeted NGS analysis of 21 H-TAD associated genes. In addition, the eXome hidden Markov model (XHMM; an algorithm to identify CNVs in targeted NGS data) was used to detect CNVs in these genes. A pathogenic or likely pathogenic variant was found in 66 of 810 patients (8.1%). Of these 66 pathogenic or likely pathogenic variants, six (9.1%) were CNVs not detectable by routine NGS analysis. These CNVs were four intragenic (multi-)exon deletions in MYLK, TGFB2, SMAD3, and PRKG1, respectively. In addition, a large duplication including NOTCH1 and a large deletion encompassing SCARF2 were detected. As confirmed by additional analyses, both CNVs indicated larger chromosomal abnormalities, which could explain the phenotype in both patients. Given the clinical relevance of the identification of a genetic cause, CNV analysis using a method such as XHMM should be incorporated into the clinical diagnostic care for H-TAD patients.

Acute brain ischemia as a complication of the Ehlers-Danlos syndrome, the case series

Vascular type of Ehlers-Danlos syndrome involves many severe complications leading not only to organ-specific symptoms but often ends in a sudden death. The aim of this paper was to present a diagnostic possibilities and its efficiency rate in patients with vascular complications of Ehlers-Danlos syndrome who suffered from artery dissection resulting in acute brain or limb ischemia. We analysed three patients with diagnosed Ehlers-Danlos syndrome who were referred to radiology department for diagnostic imaging of affected vascular beds, each experienced brain ischemia. The paper also aims at offering some general recommendations for patients suffering from possible complications of type IV Ehlers-Danlos syndrome basing on our own experience and available literature data.

Treatment of vascular Ehlers-Danlos syndrome: a systematic review

OBJECTIVE

To provide the collected evidence from all literature reports.

BACKGROUND

Vascular Ehlers-Danlos syndrome (EDS) is a rare connective tissue disorder with serious hemorrhagic consequences. Most experience on treatment is based on case reports and small case series.

METHOD

A systematic literature review was performed. PubMed and reference lists were scrutinized.

RESULTS

A total of 231 patients were identified with no gender preponderance. Aneurysms were present in 40%, often multiple. In 33%, there was an arterial rupture without an underlying aneurysm. Carotidocavernous fistula was seen in 18%. After open surgery the mortality was 30%; after endovascular procedures, it was 24%; in a group of miscellaneous cases, it was 60%; and the overall mortality was 39%. The median age of patients at death was 31 years. The median follow-up time was 12 months (5 days-7 years), but in 20% cases, it was not reported. In only 29 of the 119 recent patients (24%) the mutation was verified with molecular genetic testing.

CONCLUSIONS

Vascular EDS is a serious disorder with high mortality, which does not seem to have been influenced by new treatment methods. Invasive methods should be used only when necessary, primarily to save the patients' life. Whenever possible, the genetic molecular defect should be identified. The results of this review may be affected by publications bias. Ideally, a prospective registry should be created.

COL3A1 haploinsufficiency results in a variety of Ehlers-Danlos syndrome type IV with delayed onset of complications and longer life expectancy

PURPOSE

To characterize the clinical outcome of heterozygosity for COL3A1 null mutations in Ehlers-Danlos syndrome type IV, the vascular type.

METHODS

We identified mutations that produced premature termination codons and resulted in nonsense-mediated messenger RNA decay in 19 families. We reviewed the clinical and family histories and medical complications in 54 individuals from these families with COL3A1 null mutations.

RESULTS

Compared with individuals with missense or exon-skipping mutations, we found that life span was extended, the age of first complication was delayed by almost 15 years, and major complications were limited to vascular events. The families were ascertained after a complication in a single individual, but only 28% of relatives, some of whom had reached their seventies or eighties without incidents, had a complication and only 30% had minor clinical features of Ehlers-Danlos syndrome type IV CONCLUSION: Null mutations have reduced penetrance compared with missense and splicing mutations, and the phenotype seems to be limited almost entirely to vascular events.

Allele-specific siRNA knockdown as a personalized treatment strategy for vascular Ehlers-Danlos syndrome in human fibroblasts

The vascular type of the Ehlers-Danlos syndrome (vEDS) is caused by dominant-negative mutations in the procollagen type III (COL3A1) gene. Patients with this autosomal dominant disorder have a shortened life expectancy due to complications from ruptured vessels or hollow organs. We tested the effectiveness of allele-specific RNA interference (RNAi) to reduce the mutated phenotype in fibroblasts. Small-interfering RNAs (siRNAs) discriminating between wild-type and mutant COL3A1 allele were identified by a luciferase reporter gene assay and in primary fibroblasts from a normal donor and a patient with vEDS. The best discriminative siRNA with the mutation at position 10 resulted in >90% silencing of the mutant allele without affecting the wild-type allele. Transmission and immunogold electron microscopy of extracted extracellular matrices from untreated fibroblasts of the patient with vEDS revealed structurally abnormal fibrils. After siRNA treatment, collagen fibrils became similar to fibrils from fibroblasts of normal and COL3A1 haploinsufficient donors. In addition, it was shown that expression of mutated COL3A1 activates the unfolded protein response and that reduction of the amount of mutated protein by siRNA reduces cellular stress. Taken together, the results provide evidence that allele-specific siRNAs are able to reduce negative effects of mutated COL3A1 proteins. Thus, the application of allele-specific RNAi may be a promising direction for future personalized therapies to reduce the severity of vEDS.

Doxycycline ameliorates the susceptibility to aortic lesions in a mouse model for the vascular type of Ehlers-Danlos syndrome

The vascular form of Ehlers-Danlos syndrome (vEDS), a rare disease with grave complications resulting from rupture of major arteries, is caused by mutations of collagen type III [α1 chain of collagen type III (COL3A1)]. The only, recently proven, preventive strategy consists of the reduction of arterial wall stress by β-adrenergic blockers. The heterozygous (HT) Col3a1 knockout mouse has reduced expression of collagen III and recapitulates features of a mild presentation of the disease. The objective of this study was to determine whether changing the balance between synthesis and degradation of collagen by chronic treatment with doxycycline, a nonspecific matrix metalloproteinase (MMP) inhibitor, could prevent the development of vascular pathology in HT mice. After 3 months of treatment with doxycycline or placebo, 9-month-old HT or wild-type (WT) mice were subjected to surgical stressing of the aorta. A 3-fold increase in stress-induced aortic lesions found in untreated HT mice 1 week after intervention (cumulative score 4.5 ± 0.87 versus 1.3 ± 0.34 in WT, p < 0.001) was fully prevented in the doxycycline-treated group (1.1 ± 0.56, p < 0.001). Untreated HT mice showed increased MMP-9 activity in the carotid artery and decreased collagen content in the aorta; however, in doxycycline-treated animals there was normalization to the levels observed in WT mice. Doxycycline treatment inhibits the activity of tissue MMP and attenuates the decrease in the collagen content in aortas of mice haploinsufficient for collagen III, as well as prevents the development of stress-induced vessel pathology. The results suggest that doxycycline merits clinical testing as a treatment for vEDS.