What a vascular surgeon should know about familial abdominal aortic aneurysm

Status of diagnosis and therapy of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

Epidemiology of endovascular and open repair for abdominal aortic aneurysms in the United States from 2004 to 2015 and implications for screening

BACKGROUND

Contemporary national trends in the repair of ruptured abdominal aortic aneurysms (AAAs) and intact AAAs are relatively unknown. Furthermore, screening is only covered by insurance for patients aged 65 to 75 years with a family history of AAAs and for men with a positive smoking history. It is unclear what proportion of patients who present with a ruptured AAA would have been candidates for screening.

METHODS

Using the National Inpatient Sample from 2004 to 2015, we identified ruptured and intact AAA admissions and repairs using the International Classification of Diseases codes. We generated the screening-eligible cohort using previously identified proportions of male smokers (87%) and all patients with a family history of AAAs (10%) and applied these proportions to patients aged 65 to 75 years. We accounted for those who could have had a previous AAA diagnosis (17%), either from screening or an incidental detection in patients aged >75 years who had presented with AAA rupture. The primary outcomes were treatment and in-hospital mortality between patients meeting the criteria for screening vs those who did not.

RESULTS

We evaluated 65,125 admissions for ruptured AAAs and 461,191 repairs for intact AAAs. Overall, an estimated 45,037 admitted patients (68%) and 25,777 patients who had undergone repair for ruptured AAAs (59%) did not meet the criteria for screening. Of the patients who did not qualify, 27,653 (63%) were aged >75 years, 10,603 (24%) were aged <65 years, and 16,103 (36%) were women. Endovascular AAA repair (EVAR) increased for ruptured AAAs from 10% in 2004 to 55% in 2015 (P < .001), with operative mortality of 35%. EVAR increased for intact AAAs from 45% in 2004 to 83% in 2015 (P < .001), with operative mortality of 2.0%.

CONCLUSIONS

Most patients who had undergone repair for ruptured AAAs did not qualify for screening. EVAR was the primary treatment of both ruptured and intact AAAs with relatively low in-hospital mortality. Therefore, expansion of the screening criteria to include selected women and a wider age range should be considered.

Screening of siblings to patients with abdominal aortic aneurysms in Sweden

OBJECTIVE

The prevalence of Abdominal Aortic Aneurysm (AAA) is higher for First Degree Relatives to AAA-patients compared to the general population, regardless of sex. The prevalence of AAA is also higher in the North of Sweden compared to the Mid and South. A regional strong hereditary trait has been suggested as an explanation to this. The aim of this study was to investigate if siblings to AAA-patients in the North have a higher prevalence of AAA compared to siblings in the Mid-region.

DESIGN

Cohort study.

MATERIALS AND METHODS

All patients treated for AAA in a northern region (Norrbotten county, North) were screened for siblings. Consenting siblings, age 40-80, were examined (n = 379) with ultrasound. The results were compared to the previously published results of 150 ultrasound-screened siblings in the Mid-region (Stockholm county).

RESULTS

The male/female ratio in the sibling cohort was 48% vs 52%. The prevalence of AAA in siblings in the North was 37/379 (brothers 14%, sisters 6%). This was not different from the prevalence among the Mid-region siblings 16/150 (brothers 17%, sisters 6% (p = 0.75). The distribution of risk factors was similar in the two regions.

CONCLUSION

The results reinforce the importance of a more systematic approach towards selective screening of all siblings to AAA patients. Ultrasound should be performed in all eligible siblings, since the distribution of AAA is similar over regions. A correlation between the familial distribution and the reported high prevalence of AAA in general population in the North could not be shown.

Endovascular treatment of genetically linked aortic diseases

Background

The most important structural proteins of the vascular wall are collagen and elastin. Genetically linked connective tissue diseases lead to degeneration, aneurysm formation and spontaneous dissection or rupture of arteries. The most well-known are Marfan syndrome, vascular Ehlers-Danlos syndrome (type IV), Loeys-Dietz syndrome and familial aortic aneurysms and dissections.

Objective

This review article addresses the current status of endovascular treatment options for important connective tissue diseases.

Material and methods

Evaluation of currently available randomized studies and registry data.

Results

The treatment of choice for patients that are mostly affected at a young age is primarily conservative or open repair. There is only limited evidence for endovascular aortic repair (EVAR) of abdominal aneurysms or thoracic endovascular aortic repair (TEVAR).

Conclusion

The progression of the disease with dilatation leads to secondary endoleaks and high reintervention rates with uncertain long-term results. For this reason, there is currently consensus that EVAR and TEVAR should be limited to justified exceptional cases and emergency situations in patients with genetically linked aortic diseases.