The authors have declared that no competing interests exist.
To describe the epidemiological, clinical and arterial Doppler ultrasound aspects of abdominal aortic aneurysm (AAA).
This is a prospective study with descriptive and analytical aims carried out from January 2019 to March 2022 (3 years) at the cardiovascular exploration center (CEC) "Saint-Esprit" of the association of the people's doctors for the research on cardiovascular diseases (AMP-MCV), at the clinic "Le Printemps" and at the University Hospital of Kara. All patients who underwent arterial Doppler ultrasound of the lower limbs for any reason in these centers during the study period were included. Ultrasound scans were performed or confirmed by a physician with a diploma specializing in vascular Doppler ultrasound.
We retained 32 Doppler ultrasound scans out of 739 performed for AAA with a frequency of 4.38%. The mean age was 73.5± 9.07 years. The sex ratio M/F was 1.4. The cardiovascular medical history (84.38%) found was: hypertension (33.33%), diabetes (18.52%), dyslipidemia (33.33%) and a combination of diabetes and hypertension (14.81%). The circumstances of discovery were: downstream MI ischemia (72%), incidental finding on abdominal ultrasound (15.63%) and De bakey sign (6.25%). The location of the aneurysms was subrenal (84.4%), suprarenal (9.4%) and both (6.2%). AAAs were fusiform (71.9%) and saccular (28.1%). The size of the aneurysms was greater than 5 cm in 78.17% of patients. High blood pressure increases the probability of the occurrence of subrenal AAA while dyslipidemia increases the occurrence of fusiform AAA. Diabetes increases the probability of occurrence of AAA larger than 7cm. AAAs were thrombosed in 75% of patients. There were extensions of the aneurysms to the iliac arteries in 70.59%. Downstream embolic complications represented 46.88%, in the form of occlusions and tight stenoses. Spontaneous mortality was 81.24%.
Arterial Doppler ultrasonography is a very important tool in the screening, positive and lesion diagnosis of AAA. The risk factors for AAA are: age over 60 years, male gender, hypertension, diabetes and dyslipidemia. Early detection remains essential, because the spontaneous prognosis is poor.
Aneurysm of the abdominal aorta (AAA) is a localized dilation of the abdominal aorta by at least half its normal diameter resulting in permanent loss of edge parallelism, turbulence of blood flow, and thrombus formation
In Africa, a study conducted on a population at risk of AAA in Benin in 2014 noted 1 case of AAA out of 245 patients selected, i.e. 0.41% of the population screened
The cardiovascular exploration center (CEC) "Saint-Esprit" of the Association of People's Physicians for Research on Cardiovascular Diseases (AMP-MCV) in Lomé, the clinic "Le Printemps à Lomé" and the cardiology department of the CHU-Kara (located 450 km from Lomé) served as the setting for our study. There were no vascular exploration activities as such in the two cardiology departments of the two university hospitals of Lomé.
This was a prospective study with descriptive and analytical purposes that took place from January 2019 to March 2022 (3 years 2 months).
We included all patients who had undergone arterial Doppler ultrasound of the lower limbs, regardless of the reason, age, and sex in the centers selected for the study and during the study period.
AAA and its characteristics had to be confirmed on arterial Doppler ultrasound by the physician-cardiologist specialized in vascular Doppler explorations.
The performance of abdominal aortic angioscan was not essential for the inclusion of patients in this study.
Patients referred for suspected AAA in whom we did not have confirmation on arterial Doppler ultrasound were not́ retained in the study.
The same applies to patients with abdominal aortic dilatation less than 30 mm. Nonconsent to participate in the survey was also eliminatory.
In accordance with the technique for performing lower extremity arterial ultrasound, we always started and systematically explored the aorto-iliac axes in all patients.
AAA was defined as a rounded arterial vascular structure in cross section with a diameter greater than or equal to 30 millimeters that may have an anechogenic image corresponding to the aortic lumen and a more echogenic image corresponding to the thrombus. Longitudinal sections allowed us to identify the shapes of these AAAs, their location and extension. Extension to the visceral and iliac arteries was defined by an increase of one and a half times the normal size of these arteries. Arterial stenoses were defined as high peak systolic velocity with spectral dispersion and significant downstream pressure drop with flow demodulation. Occlusions were defined by 2-dimensional visualization of total or >90% obstruction (subocclusion) of the artery associated with an absence of pulsed or color Doppler at the artery or the presence of abutting flow.
Patients or accompanying persons were asked to answer questions on a predeveloped survey form.
Arterial Doppler ultrasounds were performed or confirmed by a cardiologist certified in vascular Doppler ultrasound.
Ultrasound checks were scheduled for 3 months with the possibility of a telephone link at any time.
For each patient, we were interested in sociodemographic data (age, sex); medical history, particularly cardiovascular and family AAA; and arterial Doppler ultrasound data.
All data were initially collected on a predefined survey form. Data were analyzed by Rstudio software version 4.1.0. We performed a descriptive and then univariate and multivariate analytical analysis. The qualitative variables were presented as numbers and frequencies, the quantitative variables as mean, standard deviation and extremes. The statistical tests used were the Pearson Chi-square test for qualitative variables and the Mann-Whitney test for quantitative variables. The significance level was set at 0.05. Univariate and multivariate logistic regression was performed to search for factors associated with aneurysm location, size, and shape.
Because ethical and deontological rules govern scientific research, we kept the patients anonymous in the evaluation forms to respect medical confidentiality.
During the study period, out of 729 arterial Doppler ultrasounds performed, 32 (4.38%) were selected according to our inclusion criteria in the three selected centers in the country.
The age of the included patients ranged from 53 to 95 years, with a mean of 73.5± 9.07 years. The most represented age group was 66 to 75 years (43.75%). Males represented 18 cases (56.25%) with a sex ratio M/F of 1.4 (
Male | Female | |||
n | (%) | n | % | |
50– 65 | 4 | 09,38 | 02 | 09,38 |
66 – 75 | 9 | 28,13 | 05 | 15,63 |
76 – 85 | 5 | 12,50 | 05 | 18,75 |
86 – 95 | 0 | 00,00 | 02 | 06,25 |
Total | 18 | 56,25 | 14 | 43,75 |
The patients included in this study had a cardiovascular medical history in 84.38% (27 patients). High blood pressure (28.13%), diabetes (15.63%), and dyslipidemia (28.13%) were the major cardiovascular risk factors present in our patients. There was no smoking or family aneurysm in our series.
In 25 patients (78.13%), AAAs were discovered by downstream ischemia in the lower limbs, including 7 (28%) acute ischemia and 18 (72%) chronic ischemia. In 5 patients (15.63%) it was an incidental finding on abdominal ultrasound (
Numbers (n) | Frequencies (%) | |
Ischémie chroniqueChronic ischemia | 18 | 56,25 |
Diabetic foot (gangrene) | 5 | 15,63 |
AOMI stage III | 8 | 25,00 |
AOMI stage IV (gangrene) | 5 | 15,63 |
Acute MI ischemia | 7 | 21,88 |
Incidental discovery | 5 | 15,63 |
Flailing abdominal mass | 2 | 06,25 |
AOMI : Arteriopathy obliterating the lower limbs MI * : Lower limb
AAAs were subrenal in 27 patients (84.83%). Statistical analysis showed no significant association between age groups and aneurysm site. Similarly, there was no significant association between sex and AAA site.
High blood pressure was associated with the suprarenal location of the aneurysms with a p=0.012 and dyslipidemia with the subrenal location with a p=0.004 (
Subrenal | Sus renal | Sub and sus renal | |||||||
n (N=27) | n/N | P | n (N=3) | n/N | P | n (N=2) | n/N | p | |
HTA | 7 | 25,92 | 0,52 | 2 | 66,67 | 0,01 | 00 | 00 | 0,38 |
Diabetes | 4 | 14,81 | 0,40 | 0 | 00,00 | 0,16 | 1 | 50 | 0,44 |
HTA+Diabetes | 2 | 7,40 | 0,22 | 1 | 33,33 | 0,42 | 1 | 50 | 0,48 |
Dyslipidemia | 9 | 33,33 | 0,004 | 0 | 00,00 | 0,13 | 0 | 00 | 0,18 |
AAAs were fusiform in 23 patients (71.9%). The saccular aneurysm was present in 9 patients (28.1%).
Statistical analysis did not show a significant association between age and the shape of the AAAs. Similarly, the statistical analysis did not show a significant association between age groups and aneurysm shape. High blood pressure was associated with the saccular shape of the aneurysms with a p=0.01 (
Fusiform Aneurysm | Saccular Aneurysm | ||||
n (N=23) | n/N | n (N=9) | n/N | p | |
HTA | 6 | 26,08 | 3 | 33,33 | 0,01 |
Diabetes | 4 | 17,39 | 1 | 11,11 | 0,23 |
HTA+Diabetes | 2 | 8,70 | 2 | 22,22 | 0,17 |
Dyslipidemia | 7 | 30,43 | 2 | 22,22 | 0,07 |
HTA: High Blood Pressure
The mean size was 7.43 cm in this study. AAAs of size greater than or equal to 5 were found in 25 patients (78.14%)
|
|
|
---|---|---|
(3-4) | 01 | 03,13 |
(4-5) | 06 | 18,75 |
(5-6) | 07 | 21,88 |
(6-7) | 07 | 21,88 |
≥7 | 11 | 34,38 |
Total | 32 | 100,0 |
Statistical analysis showed no significant association between sex and aneurysm size. Patients with diabetes had larger AAA sizes p= 0.008 (
CRF | (3-4) | (4-5) | (5-6) | (6-7) | ≥7 | P | |||||
n(N=1) | n/N | n(N=5) | n/N | n(N=6) | n/N | n(N=7) | n/N | n(N=11) | n/N | ||
HTA | 1 | 100,00 | 2 | 40,00 | 4 | 66,67 | 2 | 28,57 | 0 | 00,00 | 0,216 |
Diabetes | 0 | 0,00 | 0 | 00,00 | 0 | 00,00 | 0 | 00,00 | 5 | 45,45 | 0,008 |
HTA+Diabetes | 0 | 0,00 | 2 | 40,00 | 2 | 33,33 | 0 | 00,00 | 0 | 00,00 | 0,21 |
Dyslipidemia | 0 | 0,00 | 1 | 20,00 | 0 | 00,00 | 5 | 71,42 | 3 | 27,27 | 0,52 |
CRF= Cardiovascular Risk Factors
Aneurysms were thrombosed in 24 patients (75%). (
Numbers (n) | Frequencies (%) | |
Occlusion (N=11) | 11 | 34,38 |
Iliac arteries | 2 | 18,18 |
Femoral arteries | 5 | 45,45 |
Popliteal arteries | 1 | 09,09 |
Tibial arteries | 2 | 18,18 |
Fibular arteries | 1 | 09,09 |
Stenosis (N=4) | 4 | 12,50 |
Iliac arteries | 1 | 25,00 |
Femoral arteries | 1 | 25,00 |
Popliteal arteries | 0 | 00,00 |
Tibial arteries | 2 | 50,00 |
Fibular arteries | 0 | 00,00 |
The aneurysms had extensions to other arteries in 21 patients (65.63%) distributed as follows: superior mesenteric artery (11.76%) (
Of the 32 patients surveyed, 26 patients (81.25%) died, and 3 patients were lost to follow-up. Only one patient was able to undergo surgery in Europe. Death occurred by sudden death at home according to the parents in 19 patients (73.08%); in the other 7 patients (26.92%), death occurred as a result of ischemic complications downstream of the aneurysm.
We selected 32 cases (4.39%) of AAA in patients at very high cardiovascular risk and especially who had downstream ischemic complications. There may be a recruitment bias compared with screening in an asymptomatic population. This bias may explain our high mean age of 73.50 9.07 years compared to that reported by Papa Diengi (64years) in 2015 in Senegal
Usually, AAAs are discovered incidentally, during a paraclinical examination such as abdominal ultrasound, arterial Doppler ultrasound, abdominal CT scan or abdominal MRI
In 84.4% of patients, the AAA was subrenal. These results corroborate those of Papa Diengi in Senegal who found 63.5% of AAA under the kidney
AH was associated with the suprarenal location with a p=0.01 and dyslipidemia with the subrenal location with a p=0.04. Baleato et al had made the same findings
AAAs were fusiform in 23 (71.9%) of our patients. Saccular AAAs were present in nine patients (28.1%). Beredji had reported 72.5% of cases of fusiform aneurysms and 27.5% of saccular aneurysms
Patients with AAAs larger than 5 cm accounted for 78%, including 34.38% with sizes larger than 7 cm. There was no significant association between age and AAA size. Gender was not associated with AAA size; however, there was a significant association between diabetes and aneurysms larger than 5 cm in our series. Diabetic patients are at high cardiovascular risk and have significant arterial remodeling in the intima; therefore, more extensive and accelerated embrittlement of the aortic intimal walls.
Intraaneurysmal thrombotic complications were present in 75% of cases in this study. Kunishige reported 70% thrombotic complications in Japan
Arterial occlusion downstream of the aneurysm was found in 73.33% of cases in this study. Faries reported 80% of occlusions downstream of AAAs in the USA
The mortality rate in our study was 81.25%. Basnyat in Wales
Abdominal aortic aneurysms are serious and fatal pathologies. They are often asymptomatic, poorly detected and poorly documented, even in populations at risk in Africa. In this study, the circumstances of discovery of AAAs are dominated by downstream complications such as ischemia at the gangrene stage most often. The clinical picture is confused with stage III and IV PIA. These patients could be qualified as incidental findings in our context. Because the dreaded complication of AAA remains rupture with sudden death. This is why early detection is necessary, especially in populations at risk.
Aorto-iliac Doppler ultrasonography is a very important, inexpensive, non-invasive, and reproducible tool for the positive and lesion diagnosis of abdominal aortic aneurysms with a sensitivity and specificity close to 100% in well-trained operators. It is also the tool of recommendation for early detection in order to institute early management or monitoring to avoid sudden rupture of very poor prognosis even in developed countries.
The site of AAA predominate in the subrenal aorta. Aneurysms are fusiform, thrombosed and present extensions to other arteries.
The prevention of aortic aneurysm in patients at risk requires a good control of cardiovascular risk factors and a systematic screening from 60 years old as well as the systematic realization of autopsies. Other studies could focus on mass screening for AAA throughout the Togolese territory in at-risk populations.