A.P.M. Boll

Association of the TGF-beta receptor genes with abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a multifactorial condition. The transforming growth factor β (TGF-β) pathway regulates vascular remodeling and mutations in its receptor genes, TGFBR1 and TGFBR2, cause syndromes with thoracic aortic aneurysm (TAA). The TGF-β pathway may be involved in aneurysm development in general. We performed an association study by analyzing all the common genetic variants in TGFBR1 and TGFBR2 using tag single nucleotide polymorphisms (SNPs) in a Dutch AAA case–control population in a two-stage genotyping approach. In stage 1, analyzing 376 cases and 648 controls, three of the four TGFBR1 SNPs and nine of the 28 TGFBR2 SNPs had a P<0.07. Genotyping of these SNPs in an independent cohort of 360 cases and 376 controls in stage 2 confirmed association (P<0.05) for the same allele of one SNP in TGFBR1 and two SNPs in TGFBR2. Joint analysis of the 736 cases and 1024 controls showed statistically significant associations of these SNPs, which sustained after proper correction for multiple testing (TGFBR1 rs1626340 OR 1.32 95% CI 1.11–1.56 P=0.001 and TGFBR2 rs1036095 OR 1.32 95% CI 1.12–1.54 P=0.001 and rs4522809 OR 1.28 95% CI 1.12–1.46 P=0.0004). We conclude that genetic variations in TGFBR1 and TGFBR2 associate with AAA in the Dutch population. This suggests that AAA may develop partly by similar defects as TAA, which in the future may provide novel therapeutic options.

Relevance of bacterial cultures of abdominal aortic aneurysm contents.

BACKGROUND To establish further insight into the relevance of intraoperative bacterial cultures of abdominal aortic aneurysm contents a study was performed of the rate of occurrence of prosthetic graft infection after aneurysm repair. METHODS Bacterial cultures were obtained from 216 patients, who were followed up for more than 3.5 years after operation and studied retrospectively in a single center analysis. RESULTS Thrombus cultures yielded bacteria in 55 of 216 (25.5%) cases, including 11 of 44 (25%) cases with ruptured aneurysms. Prosthetic infections (4 of 216; 1.9%) occurred more frequently (p < 0.02) in patients with positive thrombus cultures (3 of 55; 5.5%) than in patients with negative cultures (1 of 161; 0.6%). In two patients the species isolated from the thrombus was also cultured from the vascular prosthesis, although in one graft infection other organisms were also isolated. CONCLUSIONS The presence of bacteria in the intraluminal thrombus does not appear to be an important factor in the development of graft infection after primary elective and urgent abdominal aortic aneurysm repair. Therefore routine intraoperative cultures are unnecessary unless clinical signs of infective aortitis are present.

Doppler spectrum analysis versus direct femoral artery pressure measurement for rapid assessment of aortoiliac obstruction.

Adequate patient selection is required to limit the clinical workload and improve the cost‐effectiveness of noninvasive hemodynamic evaluation of the aortoiliac system. In a prospective blinded fashion the traditional invasive technique of direct femoral artery pressure measurements and the computerized Doppler spectrum analysis of blood flow velocities in the common femoral artery were studied. Both tests for rapid assessment of aortoiliac obstruction were compared with duplex ultrasonographic imaging, using a peak systolic velocity ratio of 2.5 to demonstrate stenoses of 50% or more. In a series of 17 consecutive patients (34 aortoiliac segments) with suspected aortoiliac obstructive disease, a good level of agreement (kappa = 0.6) was found for both methods when compared with duplex scanning. Analysis of deviations from the duplex registrations indicated an overestimation of the pathologic cases using femoral artery pressure measurements and an underestimation using Doppler spectrum analysis of blood flow velocities in the common femoral artery. Both methods were well tolerated, but femoral artery pressure measurements had a higher technical failure rate. Because of its noninvasive character and its feasibility the Doppler technique is preferred for the selection of patients for more extensive duplex sonographic investigation.

18.11 High prevalence of abdominal aortic aneurysm in a primary-care screening programme

BACKGROUND The mortality rate associated with ruptured abdominal aortic aneurysm (AAA) remains high. The objective of this study was to assess the feasibility of population screening for AAA. METHODS In an area with a mixed rural and industrialized population of 60000 inhabitants, all 23 general practitioners (GPs) participated. The GPs selected from their patient lists men aged 60-80 years. Men whose condition was suitable for aortic surgery were invited for screening by a single postal letter. All men responding had aortic ultrasonography in or close to the GP surgery. Diagnosis of AAA was established when the aortic diameter was 30 mm or greater. Referral for surgery was advised for an aortic diameter of 50 mm or greater. RESULTS Of 2914 invitations, 2419 men had ultrasonography, resulting in an attendance rate of 83.0 per cent. A total of 2416 aortic measurements were made; 196 aortic aneurysms were diagnosed (prevalence 8.1 per cent). In 40 men the aortic diameter was over 50 mm. CONCLUSION Ultrasonographic screening for AAA is feasible in a primary care setting.