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Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries
Eur J Vasc Endovasc Surg (xxxx) xxx, xxx
Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries Anne Cervin 1 2
1,2,*
, Anders Wanhainen 1, Martin Björck
1
Department of Surgical Sciences, Section of Vascular Surgery, Uppsala University, Uppsala, Sweden Department of Hybrid and Interventional Surgery, Unit of Vascular Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
WHAT THIS PAPER ADDS In this paper, a high prevalence of popliteal artery aneurysm (PA) of 14.2%, was found in men with enlarged aortas at population based screening of 65 year old men. There was no correlation with the diameter of the aorta, but a correlation with the diameter of the iliac arteries was identified, suggesting a subgroup with higher risk of concomitant peripheral aneurysms. The prevalence was quite different depending on three different definitions of PA, pointing out the need for a consensus definition, and a need of follow up studies, to see how these definitions correlate with future growth, complications, and the need for surgery.
Background: Data on the prevalence of popliteal artery aneurysm (PA) are scarce and difficult to interpret as the definition differs among papers. The aim was to investigate the prevalence among men with screening detected abdominal aortic aneurysms (30 mm, AAAs) and subaneurysmal aortic dilatation (25e29 mm, SAA), and to explore whether the existence of a PA correlated with the diameters of the aorta, iliac, and femoral arteries. Methods: In Uppsala, Sweden, a county with 376 000 inhabitants, AAA screening of 65 year old men was initiated in 2006. All men with AAA and SAA also had measurements of the common iliac artery (CIA). The common femoral (CFA), superficial femoral (SFA), and popliteal arteries were evaluated at re-examination, performed after 1e2 years for AAA and five years for SAA. PA was defined as 12 mm, or 1.5 times larger than the distal SFA according to the ISCVS/SVS Ad Hoc Committee. The relationships between PA and other vessel diameters were explored. Results: A total of 19 820 65 year old men (84.6%) accepted the invitation to screening between 2006 and 2017. AAA was found in 173 (0.9%), and SAA in 149 subjects (1.1% of those screened 2006e2013, eligible for this study). In the whole cohort, 14.2% of those examined had at least one PA of any size, 3.0% were 15 mm and 2.2% 20 mm. There was no difference in PA prevalence between AAA and SAA: 15.9% vs. 12.2% (p ¼ .48). There was no difference in aortic diameter in those with or without PA (p ¼ .46), but there were significant correlations with CIA (p < .001), CFA (p < .001), and SFA (p < .001) diameters. Conclusions: A high prevalence of PA among subjects with screening detected AAA and SAA was found. PA was not correlated with the aortic diameter in this cohort, where all had dilated aortas, while correlations with peripheral and iliac artery diameters were identified. Keywords: Abdominal aortic aneurysm, Iliac artery, Screening, Popliteal artery aneurysm, Prevalence Article history: Received 26 April 2019, Accepted 31 July 2019, Available online XXX Ó 2019 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.
INTRODUCTION Popliteal artery aneurysms (PAs) are limb threatening with potential for occlusion, embolisation,1,2 and uncommonly, rupture.3 Patients treated as an emergency for PA, most * Corresponding author. Department of Hybrid and Interventional Surgery, Unit of Vascular Surgery, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden. E-mail address: [email protected] (Anne Cervin). 1078-5884/Ó 2019 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved. https://doi.org/10.1016/j.ejvs.2019.07.042
often for acute limb ischaemia, have higher risks of amputation and death than those who undergo elective surgery.2,4,5 It is of clinical importance to diagnose PAs and to offer timely intervention before complications. Data on the prevalence of PA in the population are scarce and difficult to interpret as definitions differ. Trickett et al.6 found a prevalence of 1% in a screening population of men between 65 and 80 years, with the cut off value of 15 mm. In a cohort of patients with abdominal aortic aneurysm (AAA), the prevalence was 7.6% with the definition of a dilation of 1.5 times the adjacent normal vessel or the
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
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Anne Cervin et al.
AAA screening, Uppsala County 2006-2017 Men born 1941-1952 Examination of 19 820 men (84.6 % of invited)
AAA≥30 mm
Aorta 25-29 mm
Re-examination, including peripheral arteries, after 1-2 years
Re-examination, including peripheral arteries, after 5 years Excluded 55 men born 1949-1952. Not yet re-examined
AAA≥30 mm 173 men (0.9%) Born 1941-1952 Included in study
Aorta 25-29 mm 149 men (1.1%) Born 1941-1948 Included in study
Figure 1. Study design of abdominal aortic aneurysm (AAA) screening in Uppsala County, Sweden.
contralateral normal vessel.7 There is a well known association between PA and AAA. Patients treated for PA have a concomitant AAA in 34%e40% of cases,2,8 but the prevalence of PA among patients who were diagnosed with, or operated on, AAA7,9 is less well studied. Normal vessel size is correlated with age, gender, and body size, but it is not well known how PA is correlated with aortic enlargement. The primary aim of this population based study was to examine the prevalence of PA in a male screening cohort, with either AAA (30 mm), or a subaneurysmal aorta (SAA, 25e29 mm). A secondary aim was to explore whether the prevalence of PA correlated with the diameters of the aorta, iliac, and femoral arteries. PATIENTS AND METHODS A general AAA screening programme for 65 year old men was introduced in Uppsala county in 2006. Data from this programme were prospectively collected in SweAAA, a registry of detected aortic aneurysms including length, height, comorbidities, smoking habits, and family history of aneurysmal disease, based on patient history and case notes. A special module was created for patients with SAA. This registry was created in Uppsala for scientific and clinical purposes, and although it is also used in a few other hospitals, it is not part of the national Swedvasc registry. Patients with an infrarenal aorta measuring 30 mm were re-examined after one or two years, depending on size. The maximum diameters of the common femoral (CFA), distal superficial femoral (SFA), and popliteal arteries were measured at the time of re-examination. Patients with an aorta measuring 25e29 mm were re-examined after five years, and the infra-inguinal arteries were assessed simultaneously as above (Fig. 1). The common iliac arteries were measured at the initial screening. Techniques for measurement All arteries were measured by means of the leading edge to leading edge (LELE) principle, as in the entire Swedish AAA
screening programme.10 This means that the callipers are placed on the outer layer of the anterior wall and the inner layer of the posterior wall, the structures that are most easy to identify with ultrasound. This method and its reproducibility was evaluated in a study from 2014, comparing the three different measurement techniques.11 Measurements were done with a Philips iU22 (Philips Health Care, Best, The Netherlands) or Siemens S2000 (Siemens, Erlangen, Germany) ultrasound scanner equipped with a 3e5 MHz probe. Certified sonographers performed the examinations. Definitions An aneurysmal artery was defined as 50% larger than a normal artery in agreement with suggested standards for reporting on arterial aneurysms by the SVS/ISCS Ad Hoc Committee published in 1991.12 Normal arterial values are dependent on age, sex, and body surface area (BSA). The normal diameter of the common iliac arteries was evaluated by computed tomography in the sixth and seventh decade in a study from 198813 and the cut off value for iliac aneurysms was suggested to be 20 mm. In another study from 1993, a mean value of 10.1 mm (2) for men more than 50 years old was found, questioning the norm.14 The common femoral artery was assessed in a healthy population in the seventh decade,15 giving a cut off value of 15 mm. Normal SFA diameters in a healthy population are 7.3 mm.16 PA was defined as either an absolute diameter of 12 mm, since normal values in the same age range between 7.2 and 8.9 mm,17 or 1.5 times the adjacent distal SFA. The cut off diameters for the different arterial segments are given in Table 1. The correlation between AAA and SAA and the presence of peripheral aneurysmal disease was explored. As there are few reports on normal vessel diameter at all levels, comparisons were also made with diameter as a continuous variable when exploring correlations. The effect of BSA on vessel size was evaluated. There were missing values in the measurements of the common iliac artery (CIA) (10.6%), common femoral artery
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
Popliteal Aneurysms in Men with Screening Detected AAA
(CFA) (18.0%), and the popliteal artery (16.8%), mostly because the person had not yet been re-examined. The presence or absence of thrombus was not routinely recorded. When correlations were evaluated between different arterial segments, the largest diameter of the left and right sides was used for comparison in the CIA, CFA, SFA, and the popliteal artery. Ethics The study was approved by the Regional Ethics committee of the Uppsala-Örebro region. All patients (AAA) and subjects (SAA) gave informed consent. Statistics Normal distribution was assessed visually by histogram and QeQ plots and evaluated by the KolmogoroveSmirnov test. Comparisons of continuous data were made by Student’s ttest if normally distributed, and with ManneWhitney U test if not. Correlations between continuous variables were evaluated with the Pearson coefficient if normally distributed, and with Spearman rho if not. The distribution of categorical data was evaluated by Fisher’s exact test. A trend in ordinal data was evaluated by the p value for linear by linear association (LLA). Confidence intervals were 95%. Data were analysed using IBM SPSS statistics, version 23. RESULTS Screening From 2006 to 2017 (men born 1941e1952), 23 422 men were invited to AAA screening at the age of 65. A total of 19 820 accepted (compliance 84.6%). The number with AAA was 173 (0.9%) and the number with SAA was 205 (1.0%). In the most recent cohort of men with a 25e29 mm aorta (SAA), born 1949e1952 (four year cohorts), 55 men (55/ 205, 26.9%) had not yet been re-examined and thus information on the peripheral vessels is lacking, and they were excluded from the analysis (Fig. 1). The mean age at examination of the CFA, SFA, and popliteal arteries was 68.5 years, 67.5 years in the AAA group, and 70.3 years in the SAA group, p < .001.
3
Table 1. Aneurysm definitions Arterial segment
Aneurysm definition, size of artery
Common iliac artery 20 mm Common femoral 15 mm artery Popliteal artery 12 mm or 1.5 times the distal superficial femoral artery
or family history (the presence of a first degree relative with AAA). Popliteal artery diameter and popliteal aneurysms The distribution of measurements of the popliteal artery in all legs is shown in Fig. 2. The mean and median diameter was 9 mm (CI 8.76e9.32), and 9 mm (range 5e50 mm) respectively. For all subjects, there were 49 PAs in 38 persons. Thus they were bilateral in 11/38 (28.9%), and 14.2% had a PA in any leg. In 11 arteries, the popliteal artery was 1.5 times larger than the distal SFA, and in seven of those the diameters of the popliteal arteries were also 12 mm. Eight subjects (3.0%) had at least one PA with a diameter 15 mm, and six (2.2%) with a diameter of 20 mm. Surgery after examination was performed on five patients (six legs). In two, occluded aneurysms were found, but with moderate symptoms that did not require intervention. In two legs (one patient) the SFA was occluded. There was no difference in comorbidities between those with or without PA (Table 3), except for fewer smokers in the group with PA (26.3% vs 34.8%, p ¼ .03. Those with PA had a first degree relative with an AAA in 23.7% (9/38) vs 10.3% (23/224), p ¼ .03, in those without PA. Correlations between PA and diameters of the aorta, iliac, or femoral arteries The mean diameters of the iliac arteries were larger among patients with PA than those without PA 17 mm vs. 15 mm (p ¼ .001), as were the CFA diameters 13 mm vs. 11 mm (p < .001), and the SFA diameter, 12 mm vs. 9 mm (p ¼ .001) (Fig. 3). There was no significant difference in aortic diameter between those with and without PA (p ¼ .46).
Prevalence of PA among men with screening detected AAA vs. SAA
Correlation between vessel diameters and BSA
Among the AAA, 15.9% (23/145) had a PA compared with 12.2% (15/123) in the SAA (p ¼ .48), showing no significant difference. The frequencies of PA in the whole cohort and of other concomitant aneurysms are shown in Table 2. The group with AAA differed from SAA in BSA, 2.137 (CI 2.10e2.18) vs. 2.088 (CI 2.059e2.116), p ¼ .05. The AAA group had a higher proportion of current smokers 70/173 (40.5%) vs. 43/149 (28.9%), p ¼ .013. There was no difference in the frequency of diabetes, heart disease, lung disease, hypertension, cerebrovascular disease, claudication,
There was no correlation between aortic diameter and popliteal artery diameter (Spearman rho e 0.26, p ¼ .717) while there were significant correlations between popliteal artery diameters and the diameters of CIA (Spearman rho, 0.289, p < 0.001), CFA (Spearman rho 0.486, p < .001) and SFA (Spearman rho 0.681, p < .001). BSA was correlated with the diameters of the aorta (Spearman rho 0.146, p ¼ .028), CIA (Spearman rho, 0.196, p ¼ .001) and popliteal artery (Spearman rho 0.183, p ¼ .004).
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
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Table 2. Frequency of concomitant aneurysms in different arterial segments among 322a persons with abdominal aortic aneurysm (AAA) or subaneurysmal aorta (SAA) Aneurysm
Total n (%)
AAA (n [ 173a) n (%)
SAA (n [ 149a) n (%)
p
CIA Bilateral CIA CFA Bilateral CFA PA Bilateral PA
28/289 (9.7) 6/28 (21.4) 17/267 (5.3) 4/17 (23.5) 38/268 (14.2) 11/38 (28.9)
22/157 (14.0) 5/22 (22.7) 11/146 (7.5) 2/11 (18.2) 23/145 (15.9) 8/23 (34.8)
6/132 (4.5) 1/6 (16.7) 6/121 (5.0) 2/6 (33.3) 15/123 (12.2) 3/15 (20.0)
.009 1.0 .46 .58 .48 .47
Data are presented as n (%). p values refer to comparisons between AAA and SAA. AAA ¼ abdominal aortic aneurysm (30 mm); SAA ¼ subaneurysmal aorta (25e29 mm); CIA ¼ common iliac artery aneurysm; CFA ¼ common femoral artery aneurysm; PA ¼ popliteal artery aneurysm. a Not all patients were examined in all arterial segments.
140
Mean ± SD 9.04 ± 3.32 n = 521
120
Frequency – n
100
80
60
40
20
0 0
10
20
30
40
50
Diameter of popliteal artery – mm
Figure 2. Distribution of the maximum diameters of the popliteal artery in both legs, for the Uppsala County, Sweden screening programme. SD ¼ standard deviation.
DISCUSSION In this cohort of screening detected AAA and SAA, 14.2% of those examined had at least one popliteal aneurysm of any size, with 3.0% 15 mm and 2.2% 20 mm. There was no correlation with aortic diameter, but a positive correlation with CIA diameter. The definition of a popliteal aneurysm is controversial and a number of definitions have been suggested in different reports:6,7,18,19 50% larger than a normal diameter,9 15 or 19 mm in diameter,6,7 50% larger than the adjacent vessel (i.e. the distal SFA) or 50% larger than the contralateral, non-aneurysmal artery.7,12 The problem is that it is unknown how the risk of complications and growth are associated to these different definitions.20,21 Is the risk of occlusion or embolisation an effect of a relative increase
in vessel size or are larger vessels with larger aneurysms at greater risk? In this cohort of men with a screening detected AAA or SAA, there was no correlation between aortic diameter and PAs, either in the AAA or SAA groups, or when correlating with the exact diameter as a continuous variable. The occurrence of PA was, however, correlated with CIA diameter. In a study from a screening cohort for AAA, 3% (three of 112) of patients with an AAA had a PA, defined as > 19 mm, a finding similar to this study. In the control group with a normal aortic diameter, no PAs were found. In another study of 449 subjects screened for AAA,19 no PAs (defined as 20 mm) were found, but 4.3% had popliteal arteries 10 mm. With the PA definition of 12 mm, in a retrospective study of patients diagnosed or treated for AAA, thus with much larger AAAs than in this study, the prevalence was 19%.9 In this study, if only 12 mm was used as the definition, the prevalence would be 14% in the AA group. The combined definition of 12 mm diameter and/ or 1.5 times the adjacent vessel has been used. It could be argued that in many centres, only PAs of 20 mm and more are considered for prophylactic surgery, and there is little to be gained by committing resources on searching for smaller PAs. But there are studies pointing out that even small PAs can cause complications,2,22 and it is unclear what characteristics in these small aneurysms are of importance. This investigation has the advantage of being population based, and the strength of being a longitudinal cohort study, addressing this lack of knowledge in the future. A follow up study would be valuable to see how the definition used in this study correlates with further dilatation and future complications, and such a study is in progress. That BSA will influence vessel size has been shown in other studies.14,23 A significant correlation was found between BSA and the diameter of the aorta, CIAs, and popliteal arteries. The correlation was weak (Spearman rho 0.146e0.196) however, suggesting that the subjects had true aneurysmal disease and that the enlargement of the vessels was not an effect of a larger body size. The correlation between PA and CFA aneurysms is well known,7,24 but the correlation with diameter and
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
Popliteal Aneurysms in Men with Screening Detected AAA
5
Table 3. Comorbidities and characteristics in subjects with and without popliteal artery aneurysm (PA) Characteristics
PA (n [ 38) n (%)
No PA (n [ 230) n (%)
p
Mean age at examination e y Mean BSA e m2 First degree relative with AAA Heart disease Hypertension Stroke/TIA Claudication COPD Diabetes Smoking Never Former Active
68.4 2.15 9/38 (23.6) 13/38 (34.2) 20/38 (52.6) 3/38 (7.9) 1/38 (2.6) 0/38 (0) 3/38 (7.9)
68.5 2.11 23/224 (10.3) 67/225 (29.8) 128/225 (56.9) 22/227 (9.7) 13/223 (5.8) 20/226 (8.8) 30/226 (13.3)
.73 .39 .03 .57 .72 1.0 .70 .09 .44 .02
12/38 (31.6) 28/230 (12.2) 16/38 (42.1) 122/230 (53.0) 10/38 (26.3) 80/230 (34.8)
Data are presented as n (%) unless stated otherwise. PA ¼ popliteal artery aneurysm; BSA ¼ body surface area; AAA ¼ abdominal aortic aneurysm; TIA ¼ transitory ischaemic attack; COPD ¼ chronic obstructive pulmonary disease; y ¼ years.
Diameter of the widest common iliac artery – mm
40
*
*
* 30
20
small, is the higher proportion of first degree relatives among those with PA (24% vs. 10% among those with AAA or SAA without PA). This finding supports the hypothesis that patients with infra-inguinal aneurysms or CIAs might form a specific subgroup in which hereditary factors are more important than environmental risk factors.28 This investigation is limited by the number of subjects and the length of follow up. Among the subjects with SAA some were excluded due to the follow up routines, which could lead to a type 2 error in the comparisons with AAA. Also, a control group with normal aortic diameter would have been of value, but such a control group would have had to be very large since PA is uncommon in the general population. It is, however, a first report with this focus in a longitudinal cohort study, and more data will be available in the coming years. Only then will it be possible to compare how the different suggested definitions of PA affect the future risk of growth and complications, hopefully resulting in more robust recommendations as to the ideal algorithm of follow up. In conclusion, this study points out the need for a consensus definition of PA, and follow up studies to see how this correlates with future growth and complications. With the combined definition of 12 mm and 1.5 times the adjacent vessel, there was a high prevalence of PA in this study, supporting routine popliteal artery examination in patients with screening detected AAA. The correlation with iliac artery diameter suggests that this may be a subgroup with a higher risk of PA. CONFLICT OF INTEREST None.
10
FUNDING 0 Yes
No Popliteal aneurysm
Figure 3. The maximum diameter of the iliac artery, depending on whether the patient had a popliteal aneurysm or not, for the Uppsala County, Sweden screening programme.
Swedish Research Council (Grant # K2013-64X-20406-07-3), and The Swedish Heart-Lung Foundation (Grant 2012-0353) and Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse. ACKNOWLEDGEMENTS
aneurysms of the CIAs in men is a novel finding. A trend towards higher incidence of iliac aneurysms in patients with lower extremity aneurysms was found by Diwan et al.7 but they used a different definition of PA. In a recent study on women with AAA however, a similar correlation was found. Women with CIA aneurysms had infra-inguinal aneurysms in 40%, those without only in 1.6%.25 A study of peripheral diameters in 183 patients with AAA concluded that, if the patients with peripheral aneurysms were excluded, the diameters of the infra-inguinal vessels were within the normal range.26 The inverse association with larger diameters in several arterial segments in patients with PA has been shown.27 In this study, the mean SFA diameter in the subjects without PA, 8.9 mm, is similar to normal popliteal artery values in subjects without any aneurysmal disease.17 An observation, even if the group is
Our sincerest gratitude to all the research nurses in Uppsala who registered the patients prospectively in the SweAAA database, in particular Linda Lyttkens, and to all the technicians who performed the ultrasound examinations with such dedication, in particular Terese Ahrne. REFERENCES 1 Cervin A, Tjarnstrom J, Ravn H, Acosta S, Hultgren R, Welander M, et al. Treatment of popliteal aneurysm by open and endovascular surgery: a contemporary study of 592 procedures in Sweden. Eur J Vasc Endovasc Surg 2015;50:342e50. 2 Ravn H, Bergqvist D, Bjorck M. Nationwide study of the outcome of popliteal artery aneurysms treated surgically. Br J Surg 2007;94:970e7. 3 Cervin A, Ravn H, Bjorck M. Ruptured popliteal artery aneurysm. Br J Surg 2018;105:1753e8. 4 Huang Y, Gloviczki P, Oderich GS, Duncan AA, Kalra M, Fleming MD, et al. Outcomes of endovascular and contemporary
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Anne Cervin et al. open surgical repairs of popliteal artery aneurysm. J Vasc Surg 2014;60:631e8. Bjorck M, Beiles B, Menyhei G, Thomson I, Wigger P, Venermo M, et al. Editor’s Choice: contemporary treatment of popliteal artery aneurysm in eight countries: a Report from the Vascunet collaboration of registries. Eur J Vasc Endovasc Surg 2014;47:164e71. Trickett JP, Scott RAP, Tilney HS. Screening and management of asymptomatic popliteal aneurysms. J Med Screen 2002;9:92e3. Diwan A, Sarkar R, Stanley JC, Zelenock GB, Wakefield TW. Incidence of femoral and popliteal artery aneurysms in patients with abdominal aortic aneurysms. J Vasc Surg 2000;31:863e9. Hamish M, Lockwood A, Cosgrove C, Walker AJ, Wilkins D, Ashley S. Management of popliteal artery aneurysms. ANZ J Surg 2006;76:912e5. Tuveson V, Lofdahl HE, Hultgren R. Patients with abdominal aortic aneurysm have a high prevalence of popliteal artery aneurysms. Vasc Med 2016;21:369e75. Svensjo S, Bjorck M, Gurtelschmid M, Djavani Gidlund K, Hellberg A, Wanhainen A. Low prevalence of abdominal aortic aneurysm among 65-year-old Swedish men indicates a change in the epidemiology of the disease. Circulation 2011;124:1118e23. Gurtelschmid M, Bjorck M, Wanhainen A. Comparison of three ultrasound methods of measuring the diameter of the abdominal aorta. Br J Surg 2014;101:633e6. Johnston KW, Rutherford RB, Tilson MD, Shah DM, Hollier L, Stanley JC. Suggested standards for reporting on arterial aneurysms. J Vasc Surg 1991;13:452e8. Horejs D, Gilbert PM, Burstein S, Vogelzang RL. Normal aortoiliac diameters by CT. J Comput Assist Tomogr 1988;12:602e3. Pedersen OM, Aslaksen A, Vik-Mo H. Ultrasound measurement of the luminal diameter of the abdominal aorta and iliac arteries in patients without vascular disease. J Vasc Surg 1993;17:596e601. Sandgren T, Sonesson B, Ahlgren R, Lanne T. The diameter of the common femoral artery in healthy human: influence of sex, age, and body size. J Vasc Surg 1999;29:503e10. Wolf YG, Kobzantsev Z, Zelmanovich L. Size of normal and aneurysmal popliteal arteries: a duplex ultrasound study. J Vasc Surg 2006;43:488e92.
17 Sandgren T, Sonesson B, Ahlgren AR, Lanne T. Factors predicting the diameter of the popliteal artery in healthy humans. J Vasc Surg 1998;28:284e9. 18 Claridge M, Hobbs S, Quick C, Adam D, Bradbury A, Wilmink T. Screening for popliteal aneurysms should not be a routine part of a community-based aneurysm screening program. Vasc Health Risk Manag 2006;2:189e91. 19 Morris-Stiff G, Haynes M, Ogunbiyi S, Townsend E, Shetty S, Winter RK, et al. Is assessment of popliteal artery diameter in patients undergoing screening for abdominal aortic aneurysms a worthwhile procedure. Eur J Vasc Endovasc Surg 2005;30:71e4. 20 Varga ZA, Locke-Edmunds JC, Baird RN. A multicenter study of popliteal aneurysms. Joint Vascular Research Group. J Vasc Surg 1994;20:171e7. 21 Chan O, Thomas ML. The incidence of popliteal aneurysms in patients with arteriomegaly. Clin Radiol 1990;41:185e9. 22 Ascher E, Markevich N, Schutzer RW, Kallakuri S, Jacob T, Hingorani AP. Small popliteal artery aneurysms: are they clinically significant? J Vasc Surg 2003;37:755e60. 23 Sonesson B, Lanne T, Hansen F, Sandgren T. Infrarenal aortic diameter in the healthy person. Eur J Vasc Surg 1994;8:89e95. 24 Dent TL, Lindenauer SM, Ernst CB, Fry WJ. Multiple arteriosclerotic arterial aneurysms. Arch Surg 1972;105:338e44. 25 Wallinder J, Georgiou A, Wanhainen A, Bjorck M. Prevalence of synchronous and metachronous aneurysms in women with abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2018;56: 435e40. 26 Sandgren T, Sonesson B, Ryden A, Lanne T. Arterial dimensions in the lower extremities of patients with abdominal aortic aneurysms–no indications of a generalized dilating diathesis. J Vasc Surg 2001;34:1079e84. 27 Widmer MK, Blatter S, Schmidli J, Baumgartner I, Gahl B, Carrel T, et al. Generalized dilating diathesis in patients with popliteal arterial aneurysm. Vasa 2008;37:157e63. 28 Bjorck M, Wanhainen A. Pathophysiology of AAA: heredity vs environment. Prog Cardiovasc Dis 2013;56:2e6.
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries Anne Cervin 1 2
1,2,*
, Anders Wanhainen 1, Martin Björck
1
Department of Surgical Sciences, Section of Vascular Surgery, Uppsala University, Uppsala, Sweden Department of Hybrid and Interventional Surgery, Unit of Vascular Surgery, Sahlgrenska University Hospital, Gothenburg, Sweden
WHAT THIS PAPER ADDS In this paper, a high prevalence of popliteal artery aneurysm (PA) of 14.2%, was found in men with enlarged aortas at population based screening of 65 year old men. There was no correlation with the diameter of the aorta, but a correlation with the diameter of the iliac arteries was identified, suggesting a subgroup with higher risk of concomitant peripheral aneurysms. The prevalence was quite different depending on three different definitions of PA, pointing out the need for a consensus definition, and a need of follow up studies, to see how these definitions correlate with future growth, complications, and the need for surgery.
Background: Data on the prevalence of popliteal artery aneurysm (PA) are scarce and difficult to interpret as the definition differs among papers. The aim was to investigate the prevalence among men with screening detected abdominal aortic aneurysms (30 mm, AAAs) and subaneurysmal aortic dilatation (25e29 mm, SAA), and to explore whether the existence of a PA correlated with the diameters of the aorta, iliac, and femoral arteries. Methods: In Uppsala, Sweden, a county with 376 000 inhabitants, AAA screening of 65 year old men was initiated in 2006. All men with AAA and SAA also had measurements of the common iliac artery (CIA). The common femoral (CFA), superficial femoral (SFA), and popliteal arteries were evaluated at re-examination, performed after 1e2 years for AAA and five years for SAA. PA was defined as 12 mm, or 1.5 times larger than the distal SFA according to the ISCVS/SVS Ad Hoc Committee. The relationships between PA and other vessel diameters were explored. Results: A total of 19 820 65 year old men (84.6%) accepted the invitation to screening between 2006 and 2017. AAA was found in 173 (0.9%), and SAA in 149 subjects (1.1% of those screened 2006e2013, eligible for this study). In the whole cohort, 14.2% of those examined had at least one PA of any size, 3.0% were 15 mm and 2.2% 20 mm. There was no difference in PA prevalence between AAA and SAA: 15.9% vs. 12.2% (p ¼ .48). There was no difference in aortic diameter in those with or without PA (p ¼ .46), but there were significant correlations with CIA (p < .001), CFA (p < .001), and SFA (p < .001) diameters. Conclusions: A high prevalence of PA among subjects with screening detected AAA and SAA was found. PA was not correlated with the aortic diameter in this cohort, where all had dilated aortas, while correlations with peripheral and iliac artery diameters were identified. Keywords: Abdominal aortic aneurysm, Iliac artery, Screening, Popliteal artery aneurysm, Prevalence Article history: Received 26 April 2019, Accepted 31 July 2019, Available online XXX Ó 2019 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.
INTRODUCTION Popliteal artery aneurysms (PAs) are limb threatening with potential for occlusion, embolisation,1,2 and uncommonly, rupture.3 Patients treated as an emergency for PA, most * Corresponding author. Department of Hybrid and Interventional Surgery, Unit of Vascular Surgery, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden. E-mail address: [email protected] (Anne Cervin). 1078-5884/Ó 2019 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved. https://doi.org/10.1016/j.ejvs.2019.07.042
often for acute limb ischaemia, have higher risks of amputation and death than those who undergo elective surgery.2,4,5 It is of clinical importance to diagnose PAs and to offer timely intervention before complications. Data on the prevalence of PA in the population are scarce and difficult to interpret as definitions differ. Trickett et al.6 found a prevalence of 1% in a screening population of men between 65 and 80 years, with the cut off value of 15 mm. In a cohort of patients with abdominal aortic aneurysm (AAA), the prevalence was 7.6% with the definition of a dilation of 1.5 times the adjacent normal vessel or the
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
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AAA screening, Uppsala County 2006-2017 Men born 1941-1952 Examination of 19 820 men (84.6 % of invited)
AAA≥30 mm
Aorta 25-29 mm
Re-examination, including peripheral arteries, after 1-2 years
Re-examination, including peripheral arteries, after 5 years Excluded 55 men born 1949-1952. Not yet re-examined
AAA≥30 mm 173 men (0.9%) Born 1941-1952 Included in study
Aorta 25-29 mm 149 men (1.1%) Born 1941-1948 Included in study
Figure 1. Study design of abdominal aortic aneurysm (AAA) screening in Uppsala County, Sweden.
contralateral normal vessel.7 There is a well known association between PA and AAA. Patients treated for PA have a concomitant AAA in 34%e40% of cases,2,8 but the prevalence of PA among patients who were diagnosed with, or operated on, AAA7,9 is less well studied. Normal vessel size is correlated with age, gender, and body size, but it is not well known how PA is correlated with aortic enlargement. The primary aim of this population based study was to examine the prevalence of PA in a male screening cohort, with either AAA (30 mm), or a subaneurysmal aorta (SAA, 25e29 mm). A secondary aim was to explore whether the prevalence of PA correlated with the diameters of the aorta, iliac, and femoral arteries. PATIENTS AND METHODS A general AAA screening programme for 65 year old men was introduced in Uppsala county in 2006. Data from this programme were prospectively collected in SweAAA, a registry of detected aortic aneurysms including length, height, comorbidities, smoking habits, and family history of aneurysmal disease, based on patient history and case notes. A special module was created for patients with SAA. This registry was created in Uppsala for scientific and clinical purposes, and although it is also used in a few other hospitals, it is not part of the national Swedvasc registry. Patients with an infrarenal aorta measuring 30 mm were re-examined after one or two years, depending on size. The maximum diameters of the common femoral (CFA), distal superficial femoral (SFA), and popliteal arteries were measured at the time of re-examination. Patients with an aorta measuring 25e29 mm were re-examined after five years, and the infra-inguinal arteries were assessed simultaneously as above (Fig. 1). The common iliac arteries were measured at the initial screening. Techniques for measurement All arteries were measured by means of the leading edge to leading edge (LELE) principle, as in the entire Swedish AAA
screening programme.10 This means that the callipers are placed on the outer layer of the anterior wall and the inner layer of the posterior wall, the structures that are most easy to identify with ultrasound. This method and its reproducibility was evaluated in a study from 2014, comparing the three different measurement techniques.11 Measurements were done with a Philips iU22 (Philips Health Care, Best, The Netherlands) or Siemens S2000 (Siemens, Erlangen, Germany) ultrasound scanner equipped with a 3e5 MHz probe. Certified sonographers performed the examinations. Definitions An aneurysmal artery was defined as 50% larger than a normal artery in agreement with suggested standards for reporting on arterial aneurysms by the SVS/ISCS Ad Hoc Committee published in 1991.12 Normal arterial values are dependent on age, sex, and body surface area (BSA). The normal diameter of the common iliac arteries was evaluated by computed tomography in the sixth and seventh decade in a study from 198813 and the cut off value for iliac aneurysms was suggested to be 20 mm. In another study from 1993, a mean value of 10.1 mm (2) for men more than 50 years old was found, questioning the norm.14 The common femoral artery was assessed in a healthy population in the seventh decade,15 giving a cut off value of 15 mm. Normal SFA diameters in a healthy population are 7.3 mm.16 PA was defined as either an absolute diameter of 12 mm, since normal values in the same age range between 7.2 and 8.9 mm,17 or 1.5 times the adjacent distal SFA. The cut off diameters for the different arterial segments are given in Table 1. The correlation between AAA and SAA and the presence of peripheral aneurysmal disease was explored. As there are few reports on normal vessel diameter at all levels, comparisons were also made with diameter as a continuous variable when exploring correlations. The effect of BSA on vessel size was evaluated. There were missing values in the measurements of the common iliac artery (CIA) (10.6%), common femoral artery
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
Popliteal Aneurysms in Men with Screening Detected AAA
(CFA) (18.0%), and the popliteal artery (16.8%), mostly because the person had not yet been re-examined. The presence or absence of thrombus was not routinely recorded. When correlations were evaluated between different arterial segments, the largest diameter of the left and right sides was used for comparison in the CIA, CFA, SFA, and the popliteal artery. Ethics The study was approved by the Regional Ethics committee of the Uppsala-Örebro region. All patients (AAA) and subjects (SAA) gave informed consent. Statistics Normal distribution was assessed visually by histogram and QeQ plots and evaluated by the KolmogoroveSmirnov test. Comparisons of continuous data were made by Student’s ttest if normally distributed, and with ManneWhitney U test if not. Correlations between continuous variables were evaluated with the Pearson coefficient if normally distributed, and with Spearman rho if not. The distribution of categorical data was evaluated by Fisher’s exact test. A trend in ordinal data was evaluated by the p value for linear by linear association (LLA). Confidence intervals were 95%. Data were analysed using IBM SPSS statistics, version 23. RESULTS Screening From 2006 to 2017 (men born 1941e1952), 23 422 men were invited to AAA screening at the age of 65. A total of 19 820 accepted (compliance 84.6%). The number with AAA was 173 (0.9%) and the number with SAA was 205 (1.0%). In the most recent cohort of men with a 25e29 mm aorta (SAA), born 1949e1952 (four year cohorts), 55 men (55/ 205, 26.9%) had not yet been re-examined and thus information on the peripheral vessels is lacking, and they were excluded from the analysis (Fig. 1). The mean age at examination of the CFA, SFA, and popliteal arteries was 68.5 years, 67.5 years in the AAA group, and 70.3 years in the SAA group, p < .001.
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Table 1. Aneurysm definitions Arterial segment
Aneurysm definition, size of artery
Common iliac artery 20 mm Common femoral 15 mm artery Popliteal artery 12 mm or 1.5 times the distal superficial femoral artery
or family history (the presence of a first degree relative with AAA). Popliteal artery diameter and popliteal aneurysms The distribution of measurements of the popliteal artery in all legs is shown in Fig. 2. The mean and median diameter was 9 mm (CI 8.76e9.32), and 9 mm (range 5e50 mm) respectively. For all subjects, there were 49 PAs in 38 persons. Thus they were bilateral in 11/38 (28.9%), and 14.2% had a PA in any leg. In 11 arteries, the popliteal artery was 1.5 times larger than the distal SFA, and in seven of those the diameters of the popliteal arteries were also 12 mm. Eight subjects (3.0%) had at least one PA with a diameter 15 mm, and six (2.2%) with a diameter of 20 mm. Surgery after examination was performed on five patients (six legs). In two, occluded aneurysms were found, but with moderate symptoms that did not require intervention. In two legs (one patient) the SFA was occluded. There was no difference in comorbidities between those with or without PA (Table 3), except for fewer smokers in the group with PA (26.3% vs 34.8%, p ¼ .03. Those with PA had a first degree relative with an AAA in 23.7% (9/38) vs 10.3% (23/224), p ¼ .03, in those without PA. Correlations between PA and diameters of the aorta, iliac, or femoral arteries The mean diameters of the iliac arteries were larger among patients with PA than those without PA 17 mm vs. 15 mm (p ¼ .001), as were the CFA diameters 13 mm vs. 11 mm (p < .001), and the SFA diameter, 12 mm vs. 9 mm (p ¼ .001) (Fig. 3). There was no significant difference in aortic diameter between those with and without PA (p ¼ .46).
Prevalence of PA among men with screening detected AAA vs. SAA
Correlation between vessel diameters and BSA
Among the AAA, 15.9% (23/145) had a PA compared with 12.2% (15/123) in the SAA (p ¼ .48), showing no significant difference. The frequencies of PA in the whole cohort and of other concomitant aneurysms are shown in Table 2. The group with AAA differed from SAA in BSA, 2.137 (CI 2.10e2.18) vs. 2.088 (CI 2.059e2.116), p ¼ .05. The AAA group had a higher proportion of current smokers 70/173 (40.5%) vs. 43/149 (28.9%), p ¼ .013. There was no difference in the frequency of diabetes, heart disease, lung disease, hypertension, cerebrovascular disease, claudication,
There was no correlation between aortic diameter and popliteal artery diameter (Spearman rho e 0.26, p ¼ .717) while there were significant correlations between popliteal artery diameters and the diameters of CIA (Spearman rho, 0.289, p < 0.001), CFA (Spearman rho 0.486, p < .001) and SFA (Spearman rho 0.681, p < .001). BSA was correlated with the diameters of the aorta (Spearman rho 0.146, p ¼ .028), CIA (Spearman rho, 0.196, p ¼ .001) and popliteal artery (Spearman rho 0.183, p ¼ .004).
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
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Table 2. Frequency of concomitant aneurysms in different arterial segments among 322a persons with abdominal aortic aneurysm (AAA) or subaneurysmal aorta (SAA) Aneurysm
Total n (%)
AAA (n [ 173a) n (%)
SAA (n [ 149a) n (%)
p
CIA Bilateral CIA CFA Bilateral CFA PA Bilateral PA
28/289 (9.7) 6/28 (21.4) 17/267 (5.3) 4/17 (23.5) 38/268 (14.2) 11/38 (28.9)
22/157 (14.0) 5/22 (22.7) 11/146 (7.5) 2/11 (18.2) 23/145 (15.9) 8/23 (34.8)
6/132 (4.5) 1/6 (16.7) 6/121 (5.0) 2/6 (33.3) 15/123 (12.2) 3/15 (20.0)
.009 1.0 .46 .58 .48 .47
Data are presented as n (%). p values refer to comparisons between AAA and SAA. AAA ¼ abdominal aortic aneurysm (30 mm); SAA ¼ subaneurysmal aorta (25e29 mm); CIA ¼ common iliac artery aneurysm; CFA ¼ common femoral artery aneurysm; PA ¼ popliteal artery aneurysm. a Not all patients were examined in all arterial segments.
140
Mean ± SD 9.04 ± 3.32 n = 521
120
Frequency – n
100
80
60
40
20
0 0
10
20
30
40
50
Diameter of popliteal artery – mm
Figure 2. Distribution of the maximum diameters of the popliteal artery in both legs, for the Uppsala County, Sweden screening programme. SD ¼ standard deviation.
DISCUSSION In this cohort of screening detected AAA and SAA, 14.2% of those examined had at least one popliteal aneurysm of any size, with 3.0% 15 mm and 2.2% 20 mm. There was no correlation with aortic diameter, but a positive correlation with CIA diameter. The definition of a popliteal aneurysm is controversial and a number of definitions have been suggested in different reports:6,7,18,19 50% larger than a normal diameter,9 15 or 19 mm in diameter,6,7 50% larger than the adjacent vessel (i.e. the distal SFA) or 50% larger than the contralateral, non-aneurysmal artery.7,12 The problem is that it is unknown how the risk of complications and growth are associated to these different definitions.20,21 Is the risk of occlusion or embolisation an effect of a relative increase
in vessel size or are larger vessels with larger aneurysms at greater risk? In this cohort of men with a screening detected AAA or SAA, there was no correlation between aortic diameter and PAs, either in the AAA or SAA groups, or when correlating with the exact diameter as a continuous variable. The occurrence of PA was, however, correlated with CIA diameter. In a study from a screening cohort for AAA, 3% (three of 112) of patients with an AAA had a PA, defined as > 19 mm, a finding similar to this study. In the control group with a normal aortic diameter, no PAs were found. In another study of 449 subjects screened for AAA,19 no PAs (defined as 20 mm) were found, but 4.3% had popliteal arteries 10 mm. With the PA definition of 12 mm, in a retrospective study of patients diagnosed or treated for AAA, thus with much larger AAAs than in this study, the prevalence was 19%.9 In this study, if only 12 mm was used as the definition, the prevalence would be 14% in the AA group. The combined definition of 12 mm diameter and/ or 1.5 times the adjacent vessel has been used. It could be argued that in many centres, only PAs of 20 mm and more are considered for prophylactic surgery, and there is little to be gained by committing resources on searching for smaller PAs. But there are studies pointing out that even small PAs can cause complications,2,22 and it is unclear what characteristics in these small aneurysms are of importance. This investigation has the advantage of being population based, and the strength of being a longitudinal cohort study, addressing this lack of knowledge in the future. A follow up study would be valuable to see how the definition used in this study correlates with further dilatation and future complications, and such a study is in progress. That BSA will influence vessel size has been shown in other studies.14,23 A significant correlation was found between BSA and the diameter of the aorta, CIAs, and popliteal arteries. The correlation was weak (Spearman rho 0.146e0.196) however, suggesting that the subjects had true aneurysmal disease and that the enlargement of the vessels was not an effect of a larger body size. The correlation between PA and CFA aneurysms is well known,7,24 but the correlation with diameter and
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042
Popliteal Aneurysms in Men with Screening Detected AAA
5
Table 3. Comorbidities and characteristics in subjects with and without popliteal artery aneurysm (PA) Characteristics
PA (n [ 38) n (%)
No PA (n [ 230) n (%)
p
Mean age at examination e y Mean BSA e m2 First degree relative with AAA Heart disease Hypertension Stroke/TIA Claudication COPD Diabetes Smoking Never Former Active
68.4 2.15 9/38 (23.6) 13/38 (34.2) 20/38 (52.6) 3/38 (7.9) 1/38 (2.6) 0/38 (0) 3/38 (7.9)
68.5 2.11 23/224 (10.3) 67/225 (29.8) 128/225 (56.9) 22/227 (9.7) 13/223 (5.8) 20/226 (8.8) 30/226 (13.3)
.73 .39 .03 .57 .72 1.0 .70 .09 .44 .02
12/38 (31.6) 28/230 (12.2) 16/38 (42.1) 122/230 (53.0) 10/38 (26.3) 80/230 (34.8)
Data are presented as n (%) unless stated otherwise. PA ¼ popliteal artery aneurysm; BSA ¼ body surface area; AAA ¼ abdominal aortic aneurysm; TIA ¼ transitory ischaemic attack; COPD ¼ chronic obstructive pulmonary disease; y ¼ years.
Diameter of the widest common iliac artery – mm
40
*
*
* 30
20
small, is the higher proportion of first degree relatives among those with PA (24% vs. 10% among those with AAA or SAA without PA). This finding supports the hypothesis that patients with infra-inguinal aneurysms or CIAs might form a specific subgroup in which hereditary factors are more important than environmental risk factors.28 This investigation is limited by the number of subjects and the length of follow up. Among the subjects with SAA some were excluded due to the follow up routines, which could lead to a type 2 error in the comparisons with AAA. Also, a control group with normal aortic diameter would have been of value, but such a control group would have had to be very large since PA is uncommon in the general population. It is, however, a first report with this focus in a longitudinal cohort study, and more data will be available in the coming years. Only then will it be possible to compare how the different suggested definitions of PA affect the future risk of growth and complications, hopefully resulting in more robust recommendations as to the ideal algorithm of follow up. In conclusion, this study points out the need for a consensus definition of PA, and follow up studies to see how this correlates with future growth and complications. With the combined definition of 12 mm and 1.5 times the adjacent vessel, there was a high prevalence of PA in this study, supporting routine popliteal artery examination in patients with screening detected AAA. The correlation with iliac artery diameter suggests that this may be a subgroup with a higher risk of PA. CONFLICT OF INTEREST None.
10
FUNDING 0 Yes
No Popliteal aneurysm
Figure 3. The maximum diameter of the iliac artery, depending on whether the patient had a popliteal aneurysm or not, for the Uppsala County, Sweden screening programme.
Swedish Research Council (Grant # K2013-64X-20406-07-3), and The Swedish Heart-Lung Foundation (Grant 2012-0353) and Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse. ACKNOWLEDGEMENTS
aneurysms of the CIAs in men is a novel finding. A trend towards higher incidence of iliac aneurysms in patients with lower extremity aneurysms was found by Diwan et al.7 but they used a different definition of PA. In a recent study on women with AAA however, a similar correlation was found. Women with CIA aneurysms had infra-inguinal aneurysms in 40%, those without only in 1.6%.25 A study of peripheral diameters in 183 patients with AAA concluded that, if the patients with peripheral aneurysms were excluded, the diameters of the infra-inguinal vessels were within the normal range.26 The inverse association with larger diameters in several arterial segments in patients with PA has been shown.27 In this study, the mean SFA diameter in the subjects without PA, 8.9 mm, is similar to normal popliteal artery values in subjects without any aneurysmal disease.17 An observation, even if the group is
Our sincerest gratitude to all the research nurses in Uppsala who registered the patients prospectively in the SweAAA database, in particular Linda Lyttkens, and to all the technicians who performed the ultrasound examinations with such dedication, in particular Terese Ahrne. REFERENCES 1 Cervin A, Tjarnstrom J, Ravn H, Acosta S, Hultgren R, Welander M, et al. Treatment of popliteal aneurysm by open and endovascular surgery: a contemporary study of 592 procedures in Sweden. Eur J Vasc Endovasc Surg 2015;50:342e50. 2 Ravn H, Bergqvist D, Bjorck M. Nationwide study of the outcome of popliteal artery aneurysms treated surgically. Br J Surg 2007;94:970e7. 3 Cervin A, Ravn H, Bjorck M. Ruptured popliteal artery aneurysm. Br J Surg 2018;105:1753e8. 4 Huang Y, Gloviczki P, Oderich GS, Duncan AA, Kalra M, Fleming MD, et al. Outcomes of endovascular and contemporary
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17 Sandgren T, Sonesson B, Ahlgren AR, Lanne T. Factors predicting the diameter of the popliteal artery in healthy humans. J Vasc Surg 1998;28:284e9. 18 Claridge M, Hobbs S, Quick C, Adam D, Bradbury A, Wilmink T. Screening for popliteal aneurysms should not be a routine part of a community-based aneurysm screening program. Vasc Health Risk Manag 2006;2:189e91. 19 Morris-Stiff G, Haynes M, Ogunbiyi S, Townsend E, Shetty S, Winter RK, et al. Is assessment of popliteal artery diameter in patients undergoing screening for abdominal aortic aneurysms a worthwhile procedure. Eur J Vasc Endovasc Surg 2005;30:71e4. 20 Varga ZA, Locke-Edmunds JC, Baird RN. A multicenter study of popliteal aneurysms. Joint Vascular Research Group. J Vasc Surg 1994;20:171e7. 21 Chan O, Thomas ML. The incidence of popliteal aneurysms in patients with arteriomegaly. Clin Radiol 1990;41:185e9. 22 Ascher E, Markevich N, Schutzer RW, Kallakuri S, Jacob T, Hingorani AP. Small popliteal artery aneurysms: are they clinically significant? J Vasc Surg 2003;37:755e60. 23 Sonesson B, Lanne T, Hansen F, Sandgren T. Infrarenal aortic diameter in the healthy person. Eur J Vasc Surg 1994;8:89e95. 24 Dent TL, Lindenauer SM, Ernst CB, Fry WJ. Multiple arteriosclerotic arterial aneurysms. Arch Surg 1972;105:338e44. 25 Wallinder J, Georgiou A, Wanhainen A, Bjorck M. Prevalence of synchronous and metachronous aneurysms in women with abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2018;56: 435e40. 26 Sandgren T, Sonesson B, Ryden A, Lanne T. Arterial dimensions in the lower extremities of patients with abdominal aortic aneurysms–no indications of a generalized dilating diathesis. J Vasc Surg 2001;34:1079e84. 27 Widmer MK, Blatter S, Schmidli J, Baumgartner I, Gahl B, Carrel T, et al. Generalized dilating diathesis in patients with popliteal arterial aneurysm. Vasa 2008;37:157e63. 28 Bjorck M, Wanhainen A. Pathophysiology of AAA: heredity vs environment. Prog Cardiovasc Dis 2013;56:2e6.
Please cite this article as: Cervin A et al., Popliteal Aneurysms are Common Among Men With Screening Detected Abdominal Aortic Aneurysms, and Prevalence Correlates With the Diameters of the Common Iliac Arteries, European Journal of Vascular and Endovascular Surgery, https://doi.org/10.1016/j.ejvs.2019.07.042