Size of normal and aneurysmal popliteal arteries: A duplex ultrasound study

Popliteal artery aneurysm ultrasound criteria for reporting characteristics

INTRODUCTION

Duplex ultrasound (DUS) is the modality of choice for surveillance of popliteal artery aneurysms (PAAs). However, noninvasive vascular laboratories have no standard guidelines for reporting results. This study assessed reports of PAA DUS for inclusion of information pertinent to operative decision-making and timing of surveillance.

METHODS

This study was a retrospective review of a multi-institutional repository that was queried for all patients with a PAA from 2008 to 2022 and confirmed via manual chart review. DUS reports were abstracted and images were individually annotated for features of interest including dimensions, flow abnormalities, and percent thrombus burden.

RESULTS

A total of 166 PAAs in 130 patients had at least one DUS available for viewing. Postoperative surveillance of PAAs was performed at several intervals: the first at 30 months (IQR 3.7-113, n = 44), the second at 64 months (IQR 20-172, n = 31), and the third at 152 months (IQR 46-217, n = 16) after the operation. The largest diameter of operative PAAs (median 27.5 mm, IQR 21.8-38.0) was significantly greater than nonoperative PAAs (median 20.9 mm, IQR 16.7-27.3); p < 0.01. Fewer than 33 (21%) reports commented on patency of distal runoff. We calculated an average percent thrombus of 60% (IQR 19-81) in nonoperative PAAs, which is significantly smaller than 75% (IQR 58-89) in operative PAAs; p < 0.01.

CONCLUSION

In this multi-institutional retrospective study, PAAs are often not followed at intervals recommended by the Society for Vascular Surgery guidelines and do not include all measurements necessary for clinical decision-making in the multi-institutional repository studied. There should be standardization of PAA DUS protocols performed by all noninvasive vascular laboratories to ensure completeness of PAA DUS images and inclusion of characteristics pertinent to clinical decision-making in radiology reports.

ARE SMALL POPLITEAL ANEURYSM SO INNOCENT?

OBJECTIVE

We recently recorded 5 lower limb ischemia related to a small (diameter≤20 mm) popliteal artery aneurysm (PAA) thrombosis hence we performed a retrospective data analysis on small symptomatic PAA management from our database.

METHODS

We performed a retrospective cohort study on 48 acute leg ischemia from aneurysm's thrombosis. All of them underwent surgical distal thrombectomy and bypass creation. Patients were divided into two different cohorts: GROUP A (diameter ≥20mm) and GROUP B (diameter ≤20 mm). Differences in terms of the limb salvage (end-point: the amputation rate) was analyzed and considered significative for p≤0.05. Secondary objectives were: vessel runoff recovery and patency rate. Adverse events were collected at 12 and 24 months postoperative.

RESULTS

Two year overall amputation rate was: 22.9% (11/48); 21.8% (7/32) in GROUP A and 25% (4/16) in GROUP B (RR:0.87, CI:0.29-2.55, p.80). The mean age was 68±13 years, No statistically significant differences were identified in term of primary and secondary patency (RR:0.95, CI:0.55-1.6, p.85 and (RR:0.95, CI:0.53-1.7, p.88 respectively) no differences were found in terms of comorbidities. Patients' follow-up ranged from 8 to 36 months. . In 90% of those amputated patients, the length of ischemia exceeded 4 days.Amputation rate was correlated with one runoff vessel recovery, only.

CONCLUSION

According these results small PAA are not as innocent as it is often presumed and was associated with not negligible incidence of limb loss due to thrombosis or distal embolizations also if compared to larger aneurysm. The immediate surgery is mandatory also when the ischemia exceeds 2 days.

Deep flexion helps to avoid popliteal artery injury during all-inside lateral meniscal repair: A cadaveric study

BACKGROUND

Arthroscopic meniscus repair rarely leads to major complications such as popliteal artery injury. The distance between the suturing device and the popliteal artery, and the risk of popliteal artery injury at different knee flexion angles during all-inside lateral meniscal repair remain unclear.

METHODS

All-inside devices were inserted into 10 human cadaveric knees at the posterior horn of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120° knee flexion; posterior segment of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120°; and anteromedial portal at 90°. Distance and positional relationship between the device and popliteal artery were measured radiographically.

RESULTS

In posterior horn repair through the anterolateral portal, the median distance increased from 5.7 mm at 60° to 9.1 mm at 90° (P = 0.63) and 18.0 mm at 120° (P = 0.02). The device pushed the wire at 60° in three cases, 90° in one case, and 120° in 0 cases. In posterior segment repair through the anterolateral portal, the median distance was 12.6 mm at 60°, 10.4 mm at 90°, and 18.3 mm at 120° (P = 0.08). The median distance at 90° was 18.1 mm through the anteromedial portal, the same as that at 120° through the anterolateral portal (P = 0.43), but greater than that at 90° through the anterolateral portal (P = 0.04). The wire was not pushed in any case.

CONCLUSION

Although all-inside repair of the posterior part of the lateral meniscus through the anterolateral portal is risky, deeper knee flexion reduces the risk of popliteal artery injury.

Natural history, growth rates, and treatment of popliteal artery aneurysms

BACKGROUND

The natural history of a cohort of patients monitored for popliteal artery aneurysms (PAAs) has not been well described. A prevailing uncertainty exists regarding the optimal surveillance strategies and timing of treatment. The primary aim of the present study was to describe the care trajectory of all patients with PAAs identified at two tertiary vascular centers, both in surveillance and eventually treated. The secondary aim was to define the PAA growth rates.

METHODS

A retrospective, multicenter cohort study was performed of all patients with PAAs at two vascular centers in two countries (Sweden, 2009-2016; New Zealand, 2009-2017). Data were collected from electronic medical records regarding the comorbidities, treatment, and outcomes and analyzed on a patient- and extremity-specific level. Treatment was indicated at the occurrence of emergent symptoms or considered at a PAA threshold of >2 cm. The PAAs were divided into small (≤15 mm) and large (>15 mm) aneurysms. The mean surveillance follow-up was 5.1 years.

RESULTS

Most of the 241 identified patients (397 limbs) with a diagnosis of PAAs had bilateral aneurysms (n = 156). Most patients were treated within the study period (163 of 241; 68%), and one half of the diagnosed extremities with PAA had been treated (54%; 215 of 397). Among those who had undergone elective repair, treatment had usually occurred within 1 year after the diagnosis (66%; 105 of 158). More small PAAs were detected in the group that had required emergent repair compared with elective repair (6 of 57 [11%] vs 12 of 158 [8%]; P < .001). No differences were found in the mean diameters between the elective and emergent groups (30.1 mm vs 32.2 mm; P = .39). Growth was recorded in 110 PAAs and on multivariate analysis was associated with a larger index diameter (odds ratio, 1.138; 95% confidence interval, 1.040-1.246; P = .005) and a concurrent abdominal aortic aneurysm (odds ratio, 2.553; 95% confidence interval, 1.018-6.402; P = .046).

CONCLUSIONS

The present cohort of patients represented a true contemporary clinical setting of monitored PAAs and showed that most of these patients will require elective repair, usually within 1 year. The risk of emergent repair is not negligible for patients with smaller diameter PAAs. However, the optimal selection strategy for preventive early repair is still unknown. Future morphologic studies are needed to support the development of individualized surveillance protocols.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms (PAAs) leverage the work of a panel of experts chosen by the Society for Vascular Surgery to review the current world literature as it applies to PAAs to extract the most salient, evidence-based recommendations for the treatment of these patients. These guidelines focus on PAA screening, indications for intervention, choice of repair strategy, management of asymptomatic and symptomatic PAAs (including those presenting with acute limb ischemia), and follow-up of both untreated and treated PAAs. They offer long-awaited evidence-based recommendations for physicians taking care of these patients.

Patient-specific computational fluid dynamics of femoro-popliteal stent-graft thrombosis

Intra-stent thrombosis is one of the major failure modes of popliteal aneurysm endovascular repair, especially when the diseased arterial segment is long and requires overlapping stent-grafts having different nominal diameters in order to accommodate the native arterial tapering. However, the interplay between stent sizing, post-operative arterial tortuosity, luminal diameter, local hemodynamics, and thrombosis onset is not elucidated, yet. In the present study, a popliteal aneurysm was treated with endovascular deployment of two overlapped stent-grafts, showing intra-stent thrombosis at one-year follow-up examination. Patient-specific computational fluid-dynamics analyses including straight- and bent-leg position were performed. The computational fluid-dynamics analysis showed that the overlapping of the stent-grafts induces a severe discontinuity of lumen, dividing the stented artery in two regions: the proximal part, affected by thrombosis, is characterized by larger diameter, low tortuosity, low flow velocity, low helicity, and low wall shear stress; the distal part presents higher tortuosity and smaller lumen diameter promoting higher flow velocity, higher helicity, and higher wall shear stress. Moreover, leg bending induces an overall increase of arterial tortuosity and reduces flow velocity promoting furtherly the luminal area exposed to low wall shear stress.

Simulation of blood flow into the popliteal artery to explain the effect of peripheral arterial disease: Investigation the conditions and effects of different foot states during the daily activity of the patient

BACKGROUND AND OBJECTIVE

Peripheral artery disease, one type of atherosclerosis, is a common medical condition in the world that results from plaque build-up in the peripheral blood vessels. The symptoms of this disease are the senses of pain and weakness in outer muscles.

METHODS

The artery under consideration is called the popliteal artery. In this model, the blood flow is considered as pulsating. Therefore the inlet boundary condition is taken as unsteady velocity, and the outlet boundary condition is taken the outflow. The inlet boundary condition represents the increasing systole flow and the decreasing diastole flow, which occur naturally in blood flow. Systolic flow occurs when the heart contracts and pumps blood into the arteries. The inlet blood flow is in the form of a sine-cosine parabolic profile.

RESULTS

The artery bends from the middle at an angle of 45°. As the bending of the artery begins, the flow field also takes a bent form. At this point, the flow bends from the outside of the top wall and enfolds the bottom wall in its bending. For different periods, the popliteal flow is closer to the lower bend when the inlet velocity is more significant. While the top wall experiences a low-intensity region along the bend, the bottom wall experiences the same effect just before and after the bend. As the blood flows along the bend, the flow path becomes significantly curved near the bend, similar to the model. The clotted artery exhibits a large increase in flow due to a reduction in the cross-section as a result of the clotting in half of the artery. The flow before the clotting is not considerably different from the main model of the straight artery.

CONCLUSIONS

Like shear stress, the pressure drop has a linear relationship with the blood HCT and, hence, the viscosity. The pressure drop decreases with the inlet velocity reaching its maximum value and then increases with the start of the acceleration reduction in the second and third-time steps. This indicates that the pressure drop has a stronger relationship with the acceleration than the inlet velocity.

Contrast-enhanced ultrasound (CEUS) in the diagnostic evaluation of popliteal artery aneurysms, a single-center study

BACKGROUND

Popliteal artery aneurysms (PAA) are the most common peripheral artery aneurysms. Most common cause is arteriosclerosis. Acute thromboembolic limb ischemia and rupture of the PAA depict severe complications. Diagnostic tools for identifying PAAs are (Doppler) ultrasound, CT/MR angiography and DSA.

PURPOSE

The aim of the present retrospective single-center study is to assess the application and safety of CEUS for assessing untreated and treated PAAs.

MATERIALS AND METHODS

13 patients were included in this study on whom CEUS was performed between 2007-2016. CEUS examinations were performed and interpreted by an experienced single radiologist (EFSUMB Level 3).

RESULTS

CEUS allowed for the detection of PAAs in all cases. CEUS allowed for detection of partial thrombosis of PAA in 7/8 of untreated patients, proper exclusion of PAA upon femoro-popliteal bypass in 3 patients, incomplete exclusion of PAA upon femoro-popliteal bypass in 1 patient and ruling out of in-stent stenosis in 1 patient.

CONCLUSION

CEUS is a useful and safe tool for in real-time evaluation of PAAs in the pre-/post-treatment status. In addition to conventional (Doppler) ultrasound and as an alternative tool to more elaborate imaging modalities, CEUS might be integrated in the future diagnostic work-up and follow-up of PAA patients.

Treatment of bilateral popliteal artery aneurysms

Popliteal artery aneurysms are the most frequent type of peripheral aneurysm, accounting for 85% of the all of these aneurysms. Usually asymptomatic, they are generally diagnosed during clinical examination. Incidence is higher among males and seniors. They are bilateral in 50% of the cases and 60% are associated with abdominal aortic aneurysms. This paper describes a 72-year-old male patient who presented with two bilateral pulsatile masses, one in each popliteal region, was otherwise asymptomatic, and had a history of hypertension and dyslipidemia. Clinical examination and ultrasound imaging confirmed a diagnosis of bilateral aneurysms of the popliteal arteries. Popliteal artery aneurysms can be treated with open bypass surgery, with or without aneurysm resection, or with endovascular surgery. This Therapeutic Challenge discusses these possibilities.

Ruptured popliteal artery aneurysms

Background

Rupture is a recognised complication of ruptured popliteal artery aneurysms that requires emergency intervention. There is little evidence collating the presentation, intervention and outcomes of ruptured popliteal artery aneurysms.

Objective

The primary aim of this study was to deduce the sequelae following different management modalities of ruptured popliteal artery aneurysm.

Methods

We performed a systematic review of all available cases reports of ruptured popliteal artery aneurysms in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis Protocol.

Results

We identified 48 cases taken from 35 case reports and series. Men were more commonly affected ( n = 96%), and mean age was 71 years. Acute limb ischemia was the commonest presentation (32%) whilst incidental deep vein thrombosis was found in 43% of patients. The mean aneurysm size was 8.2 cm (range, 2.7 to 13.3 cm). Management consisted of open surgery (58%), endovascular treatment (25%) and ‘other’ treatment (evacuation of haematoma, ligation of aneurysm, amputation or palliation) (17%). The perioperative mortality rate in the whole cohort was 13%. Perioperative mortality was similar between comparing the open and endovascular surgery groups. Re-intervention rate amongst endovascular patients was 25% over an average follow-up period of 14 months. There was one re-intervention in the re-constructive group (3%) over a follow-up period of 17 months and none in the ‘other’ group.

Conclusion

Popliteal artery aneurysm rupture is a serious complication associated with significant morbidity and mortality. Open surgical reconstruction and endovascular repair are both feasible for the treatment of ruptured popliteal artery aneurysms; however, open surgery is less likely to require further re-intervention.

Media sclerosis drives and localizes atherosclerosis in peripheral arteries

Media sclerosis (MS) and peripheral artery disease (PAD) may coincide, particularly in type 2 diabetics (T2D) and in patients with chronic kidney disease (CKD). In contrast to non-diabetics, in T2D PAD is more severe and more distal. Although MS is suspected to play a role, the underlying pathophysiological reasons for the differences still remain elusive today. We tested the hypothesis that MS is a promoter of atherosclerosis as it occurs in T2D with PAD by interfering with arterial remodeling using an in-silico simulation. We confirmed that MS aggravates PAD by promoting negative remodeling. We found that the effect is more pronounced in smaller distal arteries compared to larger proximal ones. Our results suggest that the degree of this divergence depends on the ratio between the thickness of the intima relative to the thickness of the media/adventitia of the individually affected arteries.

Computational Fluid Dynamics Modeling of the Burr Orbital Motion in Rotational Atherectomy with Particle Image Velocimetry Validation

Rotational atherectomy (RA) uses a high-speed rotating burr introduced via a catheter through the artery to remove hardened atherosclerotic plaque. Current clinical RA technique lacks consensus on burr size and rotational speed. The rotating burr orbits inside the artery due to the fluid force of the blood. Different from a common RA technique of upsizing burrs for larger luminal gain, a small burr can orbit to treat a large lumen. A 3D computational fluid dynamics (CFD) model was developed to simulate the burr motion and study the fluid flow and force in RA. A particle image velocimetry experiment was conducted to measure and validate the flow field including the radial and axial velocities and a pair of counter-rotating vortices near the burr equator in CFD. The hydraulic force on the burr and the contact force between the burr and the arterial wall were estimated by CFD. The contact force can be reduced by using smaller burr and lower rotational speed. Utilizing the small burr orbital motion has the potential to be an improved RA technique.

Changes in brachial artery endothelial function and resting diameter with moderate-intensity continuous but not sprint interval training in sedentary men

Moderate-intensity continuous training (MICT) improves peripheral artery function in healthy adults, a phenomenon that reverses as continued training induces structural remodeling. Sprint interval training (SIT) elicits physiological adaptations similar to MICT, despite a lower exercise volume and time commitment; however, its effect on peripheral artery function and structure is largely unexplored. We compared peripheral artery responses to 12 wk of MICT and SIT in sedentary, healthy men (age = 27 ± 8 yr). Participants performed MICT (45 min of cycling at 70% peak heart rate; n = 10) or SIT (3 × 20-s "all out" cycling sprints with 2 min of recovery; n = 9), and responses were compared with a nontraining control group (CTL, n = 6). Allometrically scaled brachial flow-mediated dilation (FMD) increased 2.2% after 6 wk of MICT and returned to baseline levels by 12 wk, but did not change in SIT or CTL (group × time interaction, P = 0.04). Brachial artery diameter increased after 6 and 12 wk (main effect, P = 0.03), with the largest increases observed in MICT. Neither training protocol affected popliteal relative FMD and diameter, or central and lower limb arterial stiffness (carotid distensibility, central and leg pulse wave velocity) (P > 0.05 for all). Whereas earlier and more frequent measurements are needed to establish the potential presence and time course of arterial responses to low-volume SIT, our findings suggest that MICT was superior to the intense, but brief and intermittent SIT stimulus at inducing brachial artery responses in healthy men.NEW & NOTEWORTHY We compared the effects of 12 wk of moderate-intensity continuous training (MICT) and sprint interval training (SIT) on peripheral artery endothelial function and diameter, and central and lower limb stiffness in sedentary, healthy men. Whereas neither training program affected the popliteal artery or stiffness indexes, we observed changes in brachial artery function and diameter with MICT but not SIT. Brachial artery responses to SIT may follow a different time course or may not occur at all.

Ruptured superficial femoral artery aneurysm: a case report

A 96-year-old male presented with left lower extremity pain, swelling, and vascular compromise. Computed tomographic angiography revealed an actively rupturing distal superficial femoral artery aneurysm. The patient underwent prompt aneurysm excision with graft interposition and had a successful postoperative outcome. Our case illustrates the critical role of imaging in establishing a definitive diagnosis and preventing mortality.

Uncommon Diseases of The Popliteal Artery: A Pictorial Review

Uncommon diseases of the popliteal artery include cystic adventitial disease, popliteal artery entrapment syndrome (PAES) and popliteal artery aneurysm (PAA). Because all of these conditions may present with pain or intermittent claudication, imaging is crucial for differentiating them and directing management. Delayed diagnosis can lead to major complications, including acute limb ischemia. Our aim is to provide an illustrative overview of these conditions in order to make radiologists aware of them and avoid misdiagnosis for timely appropriate management.

Teaching Points

• Cystic adventitial disease diagnosis is based on evidence of cysts within artery walls.

• A variety of anatomic variations may result in PAES.

• PAES may be bilateral.

• PAA is most commonly encountered in men.

• Acute complications of PAA include acute thrombosis and distal embolization.

Patients with abdominal aortic aneurysm have a high prevalence of popliteal artery aneurysms

Patients with abdominal aortic aneurysms (AAA) are more prone to develop popliteal artery aneurysms (PAA), but the prevalence is not well known. Our aim was to investigate the prevalence of PAA in patients with AAA, and to determine whether a certain risk factor profile is more commonly found in patients with concurrent aneurysms. All AAA patients (ICD code I71.3, I71.4) attending the outpatient clinic at the Karolinska University Hospital between 2011 and 2013 were included in the study cohort ( n=465); 48% (225) had been subjected to an ultrasound or computed tomography scan of their popliteal arteries. In these patients, three definitions of PAA were considered (⩾ 10.5, ⩾ 12, ⩾ 15 mm), although the overall analysis is based on PAA ⩾ 12 mm. The mean age was 70.7 years (SD 7.5), 89% were men, and the mean AAA diameter was 47 mm (SD 14). The prevalence of PAA was 19% ( n=43) by definition ⩾ 12 mm, and 11% ( n=25) with 15 mm. Claudication was more frequently found in AAA patients with PAA than patients without PAA. Sensitivity between clinical examination and radiology was 26%, and the specificity for clinical examination was 90%. In conclusion, owing to the high prevalence of PAA in AAA patients, described by us and others, the low cost and risks associated with ultrasound and the poor sensitivity at clinical examination, all women and men with AAA should undergo one radiological examination of their popliteal arteries.

Ultrasound assessment of the posterior circumflex humeral artery in elite volleyball players: Aneurysm prevalence, anatomy, branching pattern and vessel characteristics

Objectives

To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players.

Methods

Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ≥150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter.

Results

The PCHA and DBA were identified in 100 % and 93 % (260/280) of cases, respectively. The prevalence of PCHA aneurysms was 4.6 % (13/280). All aneurysms were detected in proximal PCHA originating from the axillary artery (AA). The PCHA originated from the AA in 81 % of cases (228/280), and showed a curved course dorsally towards the humeral head in 93 % (211/228). The DBA originated from the AA in 73 % of cases (190/260), and showed a straight course parallel to the AA in 93 % (177/190).

Conclusions

PCHA aneurysm prevalence in elite volleyball players is high and associated with a specific branching type: a PCHA that originates from the axillary artery. Radiologists should have a high index of suspicion for this vascular overuse injury. For the first time vessel characteristics and reference values are described to facilitate ultrasound assessment.

Key Points

• Prevalence of PCHA aneurysms is 4.6 % among elite volleyball players.

• All aneurysms are in proximal PCHA that originates directly from AA.

• Vessel characteristics and reference values are described to facilitate US assessment.

• Mean PCHA and DBA diameters can be used as reference values.

• Radiologists need a high index of suspicion for this vascular overuse injury.

The evidence-based surgical anatomy of the popliteal artery and the variations in its branching patterns

OBJECTIVE

The goal of our study was to analyze the prevalence of branching pattern variations in the popliteal artery (PA) along with morphometrics of the PA to better address its importance in disease and vascular surgical procedures.

METHODS

An extensive search for the PA and its anatomic variations was done in the major online medical databases. The anatomic data found were extracted and pooled for a meta-analysis.

RESULTS

A total of 33 studies (N = 12,757 lower limbs) were included in the analysis. The most common variant was a division of the PA below the knee into the anterior tibial artery and a common trunk for the posterior tibial and peroneal arteries, with a prevalence of 92.6% (95% confidence interval [CI], 90.2-93.8). The second most common variation was a trifurcation pattern of all three branches dividing within 0.5 cm of each other, with a prevalence of 2.4% (95% CI, 1.4-3.5). Of the three studies that reported the diameter of the PA at the level of the subcondylar plane, a mean diameter of 8 mm (95% CI, 7.29-8.70) was found.

CONCLUSIONS

The PA most commonly divides below the knee into the anterior tibial artery and the common trunk of the posterior tibial artery and the peroneal artery. Knowledge of the prevalence of possible variations in this anatomy as well as morphometric data is crucial in the planning and execution of any surgical intervention in the area of the knee.

Reliability of Ultrasound Diameter Measurements in Patients with a Small Asymptomatic Popliteal Artery Aneurysm: An Intra- and Inter-observer Agreement Study

BACKGROUND

In this study the intra- and inter-observer variability of ultrasound measurements of the diameter of the popliteal artery were tested in a group of patients under surveillance for a small (diameter 10-20 mm), asymptomatic popliteal artery aneurysm (PAA).

METHODS

From a group of patients under ultrasound surveillance for bilateral, asymptomatic PAAs, 13 consecutive patients agreed to participate in the study and provided informed consent. The maximum diameter of the popliteal arteries was assessed by a vascular technologist. The same assessment was repeated by a second vascular technologist, unaware of the results of the first measurement. After a week, this protocol was repeated. The intra- and inter-observer reliability of this measurement was calculated using intra-class correlation coefficients (ICCs) and Bland and Altman plots.

RESULTS

Of the 10 patients with bilateral and three patients with unilateral PAA, 12 completed the 2 week protocol. A total of 86 measurements were analyzed. The mean diameter of the popliteal arteries was 13.5 ± 3.4 mm. The ICC for the intra-observer reliability of observer 1 was 0.96 (95% CI 0.92-0.99), p < .001 and of observer 2 was 0.98 (95% CI 0.95-0.99), p < .001. The ICC for the inter-observer reliability for the first measurements was 0.96 (95% CI 0.90-0.98), p < .001 and for the second measurements 0.97 (95% CI 0.94-0.99), p < .001. The Bland-Altman plots showed random error, while 95% of the variation was between 0.016 and 0.16, p > .47. The absolute magnitude of the systematic error of both observers was less than 0.135 mm (median 0.00).

CONCLUSION

Ultrasound measurement of the maximum diameter of the popliteal artery is reproducible; hence, it is suitable for making a clinical treatment decision. Its use for surveillance of small, asymptomatic PAAs is justified.

Long term follow-up after endovascular brachytherapy of femoro-popliteal arteries

To perform a long term follow-up after endovascular brachytherapy (EVBT) and balloon angioplasty (PTA) regarding vessel patency and diameter. EVBT had been successfully used to decrease restenosis in short term, but long term data are lacking. Participants of a randomized study comparing EVBT and balloon angioplasty alone were invited for follow-up examination ten years after intervention. Using a standardized protocol measurement of the patency and vessel diameter was performed of femoral and popliteal arteries. 44 patients were included, 21 had been treated with EVBT and 23 had received PTA alone. Target lesion patency was similar between the two groups (90.5% vs. 87.0%). Vessel diameter of the target lesion was significantly greater in the EVBT group (6.4 mm, range 3.9-9.9) compared to the controls (5.0 mm, range 3.1-7.4; p = 0.002). Ten years after EVBT of femoro-popliteal arteries vessel diameter is significantly increased whereas patency rate is not different compared to angioplasty alone.

A Randomized Controlled Trial of Allopurinol in Patients With Peripheral Arterial Disease

Background

Patients with peripheral arterial disease (PAD) are limited by intermittent claudication in the distance they can walk. Allopurinol has been shown in coronary arterial disease to prolong exercise before angina occurs, likely by prevention of oxygen wastage in tissues and reduction of harmful oxidative stress.

Methods

In this study we evaluated whether allopurinol could prolong the time to development of leg pain in participants with PAD. In a double-blind, randomized controlled clinical trial participants were randomized to receive either allopurinol 300 mg twice daily or placebo for 6 months. The primary outcome was change in exercise capacity on treadmill testing at 6 months. Secondary outcomes were 6-minute walking distance, Walking Impairment Questionnaire, SF-36 questionnaire, flow-mediated dilatation, and oxidized low-density lipoprotein. Outcome measures were repeated midstudy and at the end of study. The mean age of the 50 participants was 68.4 ± 1.2 years with 39 of 50 (78%) male.

Results

Five participants withdrew during the study (2 active, 3 placebo). There was a significant reduction in uric acid levels in those who received active treatment of 52.1% (P < 0.001), but no significant change in either the pain-free or the maximum walking distance. Other measures of exercise capacity, blood vessel function, and the participants' own assessment of their health and walking ability also did not change during the course of the study.

Conclusions

Although allopurinol has been shown to be of benefit in a number of other diseases, in this study there was no evidence of any improvement after treatment in patients with PAD.

Acute vascular and cardiovascular responses to blood flow-restricted exercise

Blood flow-restricted resistance exercise improves muscle strength; however, the cardiovascular response is not well understood.

PURPOSE

This investigation measured local vascular responses, tissue oxygen saturation (StO2), and cardiovascular responses during supine unilateral leg press and heel raise exercise in four conditions: high load with no occlusion cuff, low load with no occlusion cuff, and low load with occlusion cuff pressure set at 1.3 times resting diastolic blood pressure (BFRDBP) or at 1.3 times resting systolic blood pressure (BFRSBP).

METHODS

Subjects (N = 13) (men/women, 5/8, 31.8 ± 12.5 yr, 68.3 ± 12.1 kg, mean ± SD) performed three sets of leg press and heel raise to fatigue with 90-s rest. Artery diameter, velocity time integral, and stroke volume were measured using two-dimensional and Doppler ultrasound at rest and immediately after exercise. HR was monitored using a three-lead ECG. Finger blood pressure was acquired by photoplethysmography. Vastus lateralis StO2 was measured using near-infrared spectroscopy. A repeated-measures ANOVA was used to analyze exercise work and StO2. Multilevel modeling was used to evaluate the effect of exercise condition on vascular and cardiovascular variables. Statistical significance was set a priori at P < 0.05.

RESULTS

Artery diameter did not change from baseline during any of the exercise conditions. Blood flow increased after exercise in each condition except BFRSBP. StO2 decreased during exercise and recovered to baseline levels during rest only in low load with no occlusion cuff and high load with no occlusion cuff. HR, stroke volume, and cardiac output (Q˙) responses to exercise were blunted in blood flow-restricted exercise. Blood pressure was elevated during rest intervals in blood flow-restricted exercise.

CONCLUSIONS

Our results demonstrate that cuff pressure alters the hemodynamic responses to resistance exercise. These findings warrant further evaluations in individuals presenting cardiovascular risk factors.

Duplex Ultrasound Findings of Popliteal Artery Aneurysms With Acute Limb Ischemia

Popliteal artery aneurysms are rare, but they have the potential to be limb threatening as a result of thrombosis and distal embolization. Duplex sonography may be used to effectively detect popliteal artery aneurysms and determine patency of the runoff arteries. Findings may include dilatation of the popliteal artery during gray-scale imaging with intraluminal heterogeneous echoes indicating the presence of mural thrombus. Abnormal or absent Doppler signals in the more distal arteries with intraluminal heterogeneous echoes may indicate the presence of thrombus, likely from embolization. This case presents the duplex sonography findings of bilateral popliteal artery aneurysms in conjunction with lower extremity acute arterial thrombosis and an abdominal aortic aneurysm.

Diagnostic ultrasonography for peripheral vascular emergencies

Over the past decade, emergency and critical care physicians have been empowered with the ability to use bedside ultrasonography to assist in the evaluation and management of a variety of emergent conditions. Today a single health care provider at the bedside with Duplex ultrasound technology can evaluate peripheral vascular calamities that once required significant time and a variety of health care personnel for the diagnosis. This article highlights peripheral thromboembolic disease, aneurysm, pseudoaneurysm, and arterial occlusion in the acute care setting.

Alternativa técnica no tratamento endovascular dos aneurismas da artéria poplítea

O aneurisma de artéria poplítea é relativamente raro, porém representa cerca de 85% de todos os aneurismas arteriais periféricos. Apresenta-se geralmente com um quadro de complicação isquêmica e elevado risco de perda do membro acometido. Em função disso, preconiza-se seu tratamento eletivo, atualmente realizado com resultados satisfatórios pela técnica endovascular. Relatamos nossa experiência com a utilização do stent de nitinol auto-expansível revestido com PTFEe - Fluency (Bard, Alemanha), reforçado internamente com o stent de nitinol auto-expansível Zilver (Cook, EUA) no tratamento de um aneurisma de artéria poplítea.

Risk of new aneurysms after surgery for popliteal artery aneurysm

Background

The risk of developing a new aneurysm after surgery for popliteal artery aneruysm (PAA) is not well known. The aim was to study this risk in a cohort of patients.

Methods

A total of 571 patients who had primary operation for PAA (717 legs) between 1987 and 2002 were identified from the Swedish Vascular Registry (Swedvasc). Of these, 190 patients were re-examined by ultrasonography after a median of 7 (range 2·9–18·7) years.

Results

The number of patients with at least one aneurysm in addition to the PAA was 108 (56·8 per cent) at the index operation and 131 (68·0 per cent) at re-examination. The overall number of aneurysms increased by 41·8 per cent, from 244 to 346. Among the 82 patients who had an isolated PAA at the index operation, 23 developed a new aneurysm; these patients tended to be older (P = 0·004). Bilateral PAA at the index operation was associated with a later development of abdominal aortic aneurysm (P = 0·004). Age (P = 0·004) and hypertension (P = 0·012) at the time of the index operation were associated with multianeurysm disease at any time. Six (4·3 per cent) of 138 legs treated by venous bypass grafts had developed a graft aneurysm by the time of re-examination. No normal arterial segment developed an aneurysm that required surgery within 3 years.

Conclusion

The development of new aneurysms was common in patients with a PAA; lifelong surveillance may be warranted.

Endovascular treatment of popliteal artery aneurysms

Popliteal artery aneurysms are relatively uncommon but potentially limb-threatening lesions that can thrombose or cause distal embolization. Identification of these aneurysms, especially in patients with abdominal aortic aneurysms, is imperative, and prophylactic treatment with either surgical exclusion and bypass or endoluminal stent grafting is critical to prevent these poor outcomes. Endovascular approaches currently using the Viabahn stent graft offer several advantages, including a minimally invasive approach, fewer perioperative complications, and a faster recovery. This must be balanced with a potentially higher failure rate or requirement for reintervention, although contemporary series report comparable short-term outcomes. We present our approach to the evaluation and diagnosis of popliteal aneurysms, the technical aspects of endovascular popliteal aneurysm repair, and a representative case study.