Popliteal artery compression and force of active plantar flexion in young healthy volunteers

An old but still valuable technique for popliteal artery stenosis: Endarterectomy via the posterior approach

Isolated popliteal artery occlusions are rare compared with femoropopliteal occlusive diseases. Although endovascular procedures have gained importance in treatment, conventional surgery remains the gold standard. In this study, we reviewed popliteal endarterectomy and patch plasty using a posterior approach. Fourteen patients who underwent surgery for isolated popliteal artery occlusions were retrospectively examined. Patients were assessed in terms of age, sex, and risk factors, such as accompanying diseases and smoking, surgical method and anesthesia, incision type, preoperative and postoperative pulse examination, ankle-brachial indices, patency, wound infection, postoperative complications, and the treatment applied. Twelve (85.7%) patients were male, and 2 (14.3%) were female. Limb ischemia was critical (ABI < 0.7) in 11 (78.5%) patients. The average duration of postoperative hospitalization was 8 ± 3.7 days on average, and the average length of follow-up was 17 ± 3.4 months. Thrombosis and complications requiring secondary intervention did not develop during the early postoperative period. While the patency rate in the first 6 months of follow-up was 100%, it was 92.8% in the 1st year and 85.7% in the 2nd year. Surgical treatment with the posterior approach in isolated popliteal artery lesions is preferred by vascular surgeons as a prioritized treatment method, with a sufficient recanalization rate and low perioperative morbidity and mortality rates. Furthermore, it is promising because it does not prevent below-knee femoropopliteal bypass, which is the subsequent stage of treatment. Moreover, the great saphenous vein was protected, and the acceptable early- and mid-term results were encouraging.

Clinical Outcomes After Drug-Coated Balloon Treatment in Popliteal Artery Disease: K-POP Registry 12-Month Results

BACKGROUND AND OBJECTIVES

The popliteal artery is generally regarded as a "no-stent zone". Limited data are available on the outcomes of drug-coated balloons (DCBs) for popliteal artery disease. This study aimed to evaluate the 12-month clinical outcomes among patients who received DCB treatment for atherosclerotic popliteal artery disease.

METHODS

This prospective, multicenter registry study enrolled 100 patients from 7 Korean endovascular centers who underwent endovascular therapy using IN.PACT DCB (Medtronic) for symptomatic atherosclerotic popliteal artery disease. The primary endpoint was 12-month clinical primary patency and the secondary endpoint was clinically driven target lesion revascularization (TLR)-free rate.

RESULTS

The mean age of the study cohort was 65.7±10.8 years, and 77% of enrolled patients were men. The mean lesion length was 93.7±53.7 mm, and total occlusions were present in 45% of patients. Technical success was achieved in all patients. Combined atherectomy was performed in 17% and provisional stenting was required in 11%. Out of the enrolled patients, 91 patients completed the 12-month follow-up. Clinical primary patency and TLR-free survival rates at 12 months were 76.0% and 87.2%, respectively. A multivariate Cox regression analysis identified female and longer lesion length as the significant independent predictors of loss of patency.

CONCLUSIONS

DCB treatment yielded favorable 12-month clinical primary patency and TLR-free survival outcomes in patients with popliteal artery disease.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02698345.

Treatment of symptomatic popliteal artery lesions: An obituary of the GORE® TIGRIS® vascular stent

BACKGROUND

The popliteal artery is highly exposed to biomechanical stress, which is the primary factor associated with stent failure. However, information on the optimal endovascular treatment for the popliteal artery is lacking.

OBJECTIVE

To report the efficacy of the GORE® TIGRIS® Vascular Stent for the endovascular treatment of popliteal artery lesions.

METHODS

Retrospective analysis of all patients with symptoms of peripheral artery occlusive disease (PAD) and popliteal artery lesions who underwent implantation of a GORE® TIGRIS® Vascular Stent between August 2012 and August 2014 at a tertiary vascular centre.

RESULTS

Between August 2012 and August 2014, 48 patients (32 men, aged 75±8 years) were treated with a GORE® TIGRIS® Vascular Stent. The technical success rate was 100%. At 12 months, the primary and secondary patency rates were 74% and 85%, respectively. During follow-up, no stent fracture was observed. No major amputations were performed.

CONCLUSIONS

Our study showed that isolated popliteal artery lesions in patients with symptomatic PAD could easily be treated with the GORE® TIGRIS® Vascular Stent, as good short-term results were achieved at 12 months. Therefore, the discontinuation of this product removed a useful tool with a simple release mechanism from the endovascular armamentarium of vascular specialists.

Vascular compression syndromes: a pictorial review

Vascular compression syndromes include a group of rare vascular changes due to extrinsic compression of veins or arteries by surrounding structures. These pathologies are often underestimated due to their rarity, clinicians’ poor level of knowledge, and the non-specificity of their symptoms. The best known are Eagle syndrome, thoracic outlet syndrome, nutcracker syndrome, May-Thurner syndrome, Dunbar syndrome, and popliteal entrapment syndrome. This work summarizes the main ultrasonographic characteristics, symptoms, and treatments of choice for these syndromes. Knowledge of these conditions’ characteristic signs is essential for the differential diagnosis. Failure to diagnose these rare diseases can expose patients to serious complications and risks to their health.

Outcomes of popliteal stent-graft placement at the artery hinge point for popliteal artery aneurysm

OBJECTIVES

to assess whether stent-grafts crossing the hinge point (HP) in the popliteal artery are associated with increased complications and decreased patency rates, after endovascular treatment of the popliteal artery aneurysm.

METHODS

This was a single-center, case-control study. Patients were allocated to either the HP group (subjects with stent-grafts crossing the HP) or the control group (subjects with stent-grafts above and/or below the HP) based on stent-graft location in the femoropopliteal artery. HP was defined as the main curve in the popliteal artery in the most acute angle toward the femur that appeared during knee flexion, which was identified by reviewing post-operative angiograms. Independent, blinded reviews were performed for all imaging data. Graft evaluation by CTA or duplex ultrasound was performed at 1, 3, 6, and 12 months and annually thereafter. Outcomes measured included: stent-graft patency, stent-graft fracture, other stent-related complications, and major adverse events, including reintervention, death, amputation, stroke, and myocardial infarction.

RESULTS

A total of 44 limbs treated with placement of heparin-bonded Viabahn endoprostheses were included in this study. Twenty and Twenty Four patients were allocated to the HP group and the control group, respectively. Primary patency rates of the HP group at 1, 2, 3, and 5 years were 84.1±8.4%, 84.1±8.4%, 84.1±8.4%, and 72.1±13.3%, respectively. The primary patency rates of the control group were 87.0±7.0%, 82.4±8.0%, 82.4±8.0%, and 82.4±8.0%, respectively. There was no significant difference between the two groups (P=0.81). No reintervention was performed in the control group. In the HP group, 5 limbs (25.0%) developed endoleak, 3 (15.0%) developed thrombosis, and one (5.0%) developed a stent fracture followed by thrombosis. Thrombosis occurred in 2 limbs (8.3%) of the control group, and stent-graft migration was observed in another 2 cases (8.3%). Neither group demonstrated stent-graft infection or acute popliteal artery embolism. Overall, incidence of stent-related complications were significantly higher in the HP group (P=0.04). Event-free survival rates of the HP group at 1, 2, 3, and 5 years were 75.0±9.7%, 69.6±10.4%, 61.9±11.8%, and 29.0±12.8%, respectively. Corresponding rates in the control group were 79.2±8.3%, 79.2±8.3%, 79.2±8.3%, and 79.2±8.3%, respectively. The difference was not statistically significant between the two groups (P=0.20) CONCLUSIONS: crossing the HP with femoropopliteal artery stent-grafts increased the risk of stent-related complications and reinterventions but did not decrease stent patency or event-free survival.

Quantification of popliteal artery narrowing with QISS MRA during active ankle plantarflexion in healthy, asymptomatic volunteers and its potential application in the diagnosis of popliteal artery entrapment syndrome (PAES)

OBJECTIVE

To assess the degree of narrowing of the popliteal artery during active ankle plantar flexion in healthy volunteers using a non-contrast quiescent-interval single-shot (QISS) magnetic resonance angiography (MRA) technique.

MATERIALS AND METHODS

Following IRB approval, 10 healthy volunteers were recruited and following informed consent underwent QISS MRA of the lower extremity at rest and during ankle plantarflexion. Two pediatric musculoskeletal radiologists independently reviewed MR images in random order and recorded a number of subjective and objective anatomic variables including branch pattern, proximity of vessel to bony structures, gastrocnemius bulk, and presence of accessory muscle. Arterial narrowing with plantarflexion was recorded by a subjective assessment of 3D reconstructions (negligible or non-negligible) and objectively by measuring the narrowest diameter during plantarflexion and at rest. Agreement between reader scores was assessed using the concordance correlation coefficient (CCC) for continuous variables, and kappa and the proportion of agreement for categorical variables.

RESULTS

Mean reduction in arterial diameter during plantar flexion was 17.1% (min 1.9%, max 64.1%, SD 16.7%) for reader 1 and 17.2% (min 1.7%, max 50.0%, SD 14.3%.) for reader 2 with high agreement between readers: CCC = 0.92 and CI = 0.82, 0.96. Arterial narrowing was described subjectively as "non-negligible" in 7/20 legs by reader 1 and 5/20 legs by reader 2 with proportion of agreement = 0.90, CI (0.77, 1.00).

CONCLUSION

We observed a wide range of popliteal arterial narrowing with plantarflexion in asymptomatic volunteers. Larger studies, for which QISS is well suited, may be invaluable for distinguishing physiologic from pathologic arterial narrowing in patients with suspected popliteal artery entrapment syndrome (PAES).

Outcomes of Drug-Coated Balloon Angioplasty for Isolated Chronic Occlusion of the Popliteal Artery: A Retrospective Single-Institution Study

PURPOSE

To assess the 12-month safety and effectiveness of paclitaxel drug-coated balloon (DCB) for the treatment of patients with isolated chronic occlusions in popliteal arteries and evaluate the risk factors of lesion reocclusion.

MATERIALS AND METHODS

From January 2018 to December 2019, DCB angioplasty was performed in 54 limbs with isolated chronic popliteal artery occlusion of 48 patients (32 men) with a mean age of 71.5 ± 12.1 (range, 50-97) years, mean occlusive length of 6.3 ± 3.0 (range, 1-15) cm, and mean preoperative ankle-brachial index (ABI) of 0.42 ± 0.12 (range, 0.19-0.58). A total of 18.5% (10/54) of lesions were long-segment occlusions involving the entire popliteal artery from P1 to P3. Twenty seven of 54 limbs presented with critical limb ischemia (CLI) with a mean ABI of 0.33 ± 0.10 (range, 0.19-0.51). The primary endpoint was primary patency rate at 12 months. The secondary endpoints included technical success rate, 1-year secondary patency rate, limb salvage rate, and improvement in clinical symptoms. Univariate Cox regression analysis was used to determine the predictors of lesion reocclusion.

RESULTS

The technical success rate was 85.2% (46/54), and bailout stenting was performed in 14.8% (8/54) of lesions. The 12-month primary and secondary patency rates by the Kaplan-Meier estimate were 72.6% and 88.3%, respectively. Two thirds of the reocclusions occurred within 6 months after intervention. No 30-day mortality was observed. The limb salvage rate was 100% during a mean follow-up period of 13 months, and all minor amputations occurred in the limbs presented with CLI. The mean ABI increased from 0.42 before the procedure to 0.73 after the procedure. Patients younger than 60 years and the lesions exhibiting long-segment occlusions present as trending risk factors for lesion reocclusion.

CONCLUSIONS

Paclitaxel DCB angioplasty is safe and effective in managing isolated chronic occlusion of popliteal arteries. Younger patients and long-segment occlusions of the popliteal artery are associated with a relatively higher reocclusion rate after the procedure.

Use of heparin coated vascular stents in femoropopliteal chronic total occlusions: Long term outcomes

PURPOSE

To evaluate the long-term clinical efficacy of the Tigris © stent (Gore ©) in femoropopliteal chronic total occlusions (CTOs).

MATERIAL AND METHODS

This single centre retrospective study included 29 patients treated with 47 Tigris© stents for CTOs. Lesion location, type, length, revascularisation method, smoking status and diabetes were reviewed. Clinical follow-up was performed. Primary safety points were complications and adverse events. Secondary efficacy points were symptom deterioration, freedom from target lesion revascularization (TLR) and amputation rate. Freedom from TLR was evaluated with Kaplan-Meier analysis; Cox multivariable logistic regression analysis of the factors associated with stent re-occlusion was also performed.

RESULTS

All procedures were technically successful without any peri- or post-procedural complications and adverse events. Median follow-up was 48 months (range: 7-70). Lesions were located in the superficial femoral (19), popliteal (3) and femoropopliteal (7) arteries with mean lesion length 13.9 ± 7.6 cm. In 12 patients subintimal recanalization was performed. Freedom from TLR rates at 6, 12, 18, 24 and 36 months were 96.6 %, 85.7 %, 81.9 %, 78.2 % and 74.3 % respectively. No stent fracture was observed and no amputation was performed in any of the patients. Smoking status, the presence of diabetes, lesion localization and recanalization type were not associated with stent re-occlusion.

CONCLUSION

This study demonstrated that use of a heparin coated vascular stent for femoropopliteal CTOs appears to offer satisfactory long-term results.

Response of the popliteal artery to treadmill exercise and stress positioning in patients with and without exertional lower extremity symptoms

OBJECTIVE

Functionally limiting exertional lower extremity pain and neurologic symptoms are commonly encountered in military and civilian settings. Exertional muscle compression of the popliteal artery (PA) and tibial nerve in the proximal calf (the "popliteal outlet") can be associated with these symptoms but is rarely investigated as a cause. Exertional ankle-brachial index (EABI) and dynamic PA ultrasound imaging may be suitable to screen for this syndrome of "functional" popliteal entrapment, but neither has been rigorously studied. Our objective was to characterize the response of the PA to lower extremity exertion and dynamic ankle positioning in symptomatic and asymptomatic limbs.

METHODS

Limbs characterized as symptomatic (n = 29) or asymptomatic (n = 61) had duplex ultrasound PA diameter and peak systolic velocity measurements with the ankle neutral and maximally plantar flexed. EABIs were obtained at rest and 1 minute and 5 minutes after walking (5 minutes, 3 mph, 10-degree incline) and running (5 minutes, 6 mph, 0-degree incline). Significance was set at P ≤ .05. Data are expressed as mean ± standard error of the mean.

RESULTS

Plantar flexion resulted in PA occlusion and changes in diameter and peak systolic velocity in symptomatic (three occluded, -2.4 ± 0.34 mm, +49 cm/s) and asymptomatic (six occluded, -1.6 ± 0.21 mm, +65 cm/s) limbs. The difference in percentage change was significant between groups only for diameter change. EABIs in both groups were similar at rest, decreased with running and walking at 1 minute, and were not fully recovered by 5 minutes. Symptomatic limbs had a greater decrease in ABI than did asymptomatic limbs with both running and walking. The decrease was greatest at 1 minute after running and significantly more pronounced in symptomatic (-0.18) than in asymptomatic (-0.02) limbs.

CONCLUSIONS

EABI decrease at 1 minute after running and PA diameter decrease with dynamic ankle plantar flexion are significantly greater in limbs with than without exertional lower extremity symptoms. These noninvasive measurements may be valuable in the workup of such symptoms. PA and tibial nerve compression at the popliteal outlet may be a more frequent cause of functionally limiting exertional lower extremity pain and neurologic symptoms than previously recognized.

Use of the Gore Tigris Vascular Stent in Advanced Femoropopliteal Peripheral Arterial Disease

PURPOSE

To prospectively evaluate the safety and efficacy of using the Tigris vascular stent (Gore, Flagstaff, Arizona) alone or in combination with the Viabahn stent (Gore) for revascularizing femoropopliteal Trans-Atlantic Intersociety Consensus (TASC) type B-D lesions with varying degrees of calcification.

MATERIALS AND METHODS

Patients with Rutherford stage ≥ 3 and TASC type ≥ B were included in the study. From January 2015 to April 2017, 31 segments in 31 patients (21 men, ovarall mean age 73.3 ± 9.2 years) were treated. The breakdown by TASC type and Rutherford stage were TASC B (n = 12), C (n = 6), and D (n = 13), and Rutherford 3 (n = 28) and 4 (n = 3). The lesions were located in the common femoral artery (n = 1), superficial femoral artery (SFA; n = 20), distal SFA to P1 (n = 3), popliteal P1 (n = 1), popliteal P1-3 (n = 3), popliteal P2-3 (n = 2), and 1 femoropopliteal bypass. There were 18 occlusions (58.1%) and 13 stenoses (41.9%). The mean diseased segment length was 15.5 ± 9.9 cm with 80.6% of moderate/severe calcification. The follow-up consisted of color Doppler ultrasound and clinical assessment at 1, 3, 6, 9, 12, and 15 months.

RESULTS

Technical success was 100%. There were no periprocedural or postprocedural complications. The mean stented lesion length was 17.2 ± 10.5 cm with a mean follow-up of 13.1 ± 6.9 months. Primary patency rates at 6, 9, 12, and 15 months were, respectively, 100% (24/31 patients), 90.5% (21/31 patients), 88.9% (20/31 patients), and 80% (15/31 patients). The median postprocedural Rutherford stage was 1. Three occlusions occurred at 7, 9, and 14 months, leading to a target lesion revascularization of 9.7% and a secondary patency of 100% at 15 months. Logistic analysis results demonstrated that lesion length (P = .003) was associated with reocclusion. Amputation-free survival at 15 months was 100%. Intrastent restenosis was observed in four cases (12.9%) but none were associated with worsening of symptoms. No stent fractures were observed.

CONCLUSIONS

The Tigris stent used alone or in combination with a Viabahn stent for femoropopliteal TASC B-D lesions demonstrated acceptable 12-month primary patency with a low reintervention rate.

Functional popliteal artery entrapment syndrome: use of ultrasound guided Botox injection as a non-surgical treatment option

OBJECTIVE

To determine whether ultrasound-guided injection of botulinum toxin type A (BTX-A) is a viable alternative to surgical intervention for the treatment of functional popliteal artery entrapment syndrome (PAES).

MATERIALS AND METHODS

Twenty-seven patients met diagnostic criteria confirming the presence of functional PAES and agreed to go ahead with ultrasound-guided BTX-A injection at the level of artery occlusion. Patients were assessed and treated at baseline and given the option for 'top-up' injections at 6 and 12 months. Patients provided subjective symptom reports at 6 and 12 months post intervention.

RESULTS

No patients reported being worse off after the intervention; 59% of patients were categorized as having a good response (i.e., initial improvement that was maintained at 12 months), 22% a mixed response (i.e., an initial improvement that subsequently reduced over 12 months) and 19% a poor response (i.e., no difference) to treatment.

CONCLUSIONS

Ultrasound-guided BTX-A injection represents a viable alternative to surgery in the treatment of functional PAES. Further study will help determine the optimum dose and frequency of injection to prevent recurrence of symptoms.

Transient Acute Leg Ischemia in a Professional Athlete Caused by Isolated Popliteal Artery Dissection Mimicking Popliteal Entrapment Syndrome

Exertional leg pain includes a broad range of conditions induced by different vascular, musculoskeletal, and neurological disorders. We report a case with isolated popliteal artery dissection as a cause of a transient acute lower limb ischemia. We report a patient with popliteal artery dissection which occurred during squatting exercise. After initial signs of transient acute limb ischemia, physical and ultrasound examination pointed to entrampment syndrome as a likely cause. However, digital subtraction angiography showed possible dissection of popliteal artery, which was confirmed intraoperatively. Popliteal artery was resected and reversed saphenous vein bypass was performed. Isolated popliteal artery dissection in professional athletes is a rare entity, which can be manifested with exertional leg pain. Clinical findings can sometimes be similar to those of popliteal entrapment syndrome. Clinical suspicion and timely patient referral to a vascular specialist are crucial for optimal treatment of this limb-threatening condition.

Two Decades of Endovascular Repair of Popliteal Artery Aneurysm--A Meta-analysis

OBJECTIVE/BACKGROUND

Over the last two decades endovascular repair (EVR) of popliteal artery aneurysms has emerged as a treatment alternative to conventional open surgical repair (OSR). The aim of this review was to evaluate the safety and efficiency of each repair method, comparing the following outcomes after EVR and OSR: (i) primary patency; (ii) operating time; (iii) length of hospital stay; (iv) peri-operative complications; (v) limb salvage; and (vi) patient survival.

METHODS

The PubMed and Cochrane Central Register of Controlled Trials were searched for publications that compared outcomes after EVR and OSR (last search November 2014). Randomized controlled trials (RCTs), prospective and retrospective observational cohort studies were included. The quality of studies was evaluated using the Newcastle-Ottawa scale and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Random effect models were employed to estimate odds ratios (ORs), mean differences, and hazard ratios (HRs).

RESULTS

One RCT combined with a prospective cohort study and four retrospective cohort studies with an overall total of 652 cases (236 EVR, 416 OSR) were identified. GRADE quality of evidence was low or very low for all outcomes. After a median follow up of 33 months, patients who received EVR showed equal primary patency rates to patients who received OSR (HR 1.46, 95% confidence interval [CI] 0.92-2.33). Lengths of operation and hospitalization were significantly shorter following EVR; rates of 30 day graft thrombosis (OR 3.16, 95% CI 1.31-7.62) and 30 day re-intervention (OR 2.15, 95% CI 1.02-4.55) were significant higher for patients who received EVR compared with those who received OSR. There was no effect on mortality (OR 2.31, 95% CI 0.37-14.49) or limb loss (OR 0.59, 95% CI 0.16-2.15).

CONCLUSION

EVR of popliteal artery aneurysm showed mid-term results comparable to open surgery and appears to be a safe alternative to OSR. However, the existing empirical evidence base is too fragmentary to draw firm conclusions. Further research and the introduction of population based registries will be needed to allow reliable evaluation of EVR.

Atheromatous occlusive lesions of the popliteal artery treated with stent grafts: predictive factors of midterm patency

BACKGROUND

Because of its location, the popliteal artery is exposed to important biomechanical constraints, inducing a specific risk of thrombosis of stents, little studied in the literature. The objective of this monocentric retrospective study was to evaluate the patency of stents implanted in the popliteal artery to treat atheromatous lesions and the risk factors predisposing to thrombosis.

METHODS

Between January 2009 and July 2013, all the patients receiving stents for a residual stenosis or a complication of angioplasty in the popliteal artery or the distal anastomosis of a femoropopliteal bypass were included retrospectively and in an intention to treat. Forty-six patients (17 women), with a 71.5 years median age (range, 45-90 years), including 17 diabetic patients (37%) and 7 hemodialysis patients (15%), were operated in 51 limbs for claudication (n = 25, 49%), critical ischemia (n = 18, 35%), or acute ischemia (n = 8, 16%). Thirty stenoses >70% (59%) and 21 thromboses (41%) were treated with 56 autoexpandable stents, with an average diameter of 6 mm (range, 5-8 mm) and an average length of 5 cm (range, 4-15 cm), including 39 lesions in P1 (above the patella), 8 in P2 (articular), and 4 in P3 (distal popliteal artery). The following factors were analyzed according to univariate and multivariate models: age, gender, Society for Vascular Surgery score, symptomatology, type and location of lesion, number of stents deployed, and dimension of stents.

RESULTS

Technical success was of 98% (n = 50), including 1 insufficient result of the endovascular treatment. At 30 days, one patient treated for critical ischemia died (2%) and one residual popliteal stenosis was treated by bypass (2%). After a 27.6 ± 10.07 month follow-up, restenosis (>50%) was detected in 5 cases including 4 asymptomatic and a popliteal thrombosis occurred in 9 cases, including 3 asymptomatic cases. Eight secondary interventions were necessary, including 4 endovascular procedures, 3 bypasses, and only 1 major amputation (thigh). The primary and secondary patencies at 12 months and 24 months were 80% and 65%, and 90% and 74%, respectively. The multivariate analysis showed that the type of lesion (stenosis versus occlusion; odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-22.9, P = 0.032) and the number of stents implanted (1 vs. 2 stents; OR [95% CI], 12.7 [1.8-88.5]; P = 0.011) were independent predictive factors of secondary thrombosis.

CONCLUSIONS

The endovascular treatment of the atheromatous popliteal lesions appears to be a satisfactory alternative. The implantation of 1 stent in the popliteal artery is recommended in the event of popliteal occlusion, whereas for a stenosis, it must be reserved for patients with residual stenosis or in the event of complications of angioplasty, such as dissection or elastic recoil. Stent must be single, with deployment of a long stent in the event of long lesion.

Functional Popliteal Artery Entrapment Syndrome: Poorly Understood and Frequently Missed? A Review of Clinical Features, Appropriate Investigations, and Treatment Options

Functional popliteal artery entrapment syndrome (PAES) is an important and possibly underrecognized cause of exertional leg pain (ELP). As it is poorly understood, it is at risk of misdiagnosis and mismanagement. The features indicative of PAES are outlined, as it can share features with other causes of ELP. Investigating functional PAES is also fraught with potential problems and if it is performed incorrectly, it can result in false negative and false positive findings. A review of the current vascular investigations is provided, highlighting some of the limitations standard tests have in determining functional PAES. Once a clinical suspicion for PAES is satisfied, it is necessary to further distinguish the subcategories of anatomical and functional entrapment and the group of asymptomatic occluders. When definitive entrapment is confirmed, it is important to identify the level of entrapment so that precise intervention can be performed. Treatment strategies for functional PAES are discussed, including the possibility of a new, less invasive intervention of guided Botulinum toxin injection at the level of entrapment as an alternative to vascular surgery.

Popliteal Artery Entrapment Syndrome

Objectives:

The purpose of this study was to report our experience with popliteal artery entrapment syndrome (PAES) with special emphasis on the applicability of duplex ultrasound scanning (DUS) when diagnosing PAES. In addition to examining the correlation between DUS and intraoperative findings in symptomatic limbs, the ultrasonic effect of plantar flexion in healthy volunteers were also evaluated.

Methods:

During a 12-month period, 11 symptomatic limbs in 8 patients with a mean age of 29 years were referred with suspected PAES and enrolled consecutively. The popliteal artery was studied preoperatively with DUS in rest and during active plantar flexion. The popliteal artery was explored in all symptomatic limbs, and the intraoperative findings served as gold standard. Additionally, the popliteal arteries in 11 healthy volunteers (22 limbs) were evaluated with DUS during rest and plantar flexion.

Results:

Intraoperative findings confirmed PAES in all 11 symptomatic limbs in accordance with the preoperative DUS examination. Surgical release of the popliteal artery was performed in 11 limbs. At a median follow-up of 15 months, all 11 limbs were free of ischemic symptoms and regained normalized popliteal flow on DUS. In the 22 symptom-free limbs, DUS showed normal popliteal flow during both rest and plantar flexion.

Conclusions:

In this series of patients with surgically confirmed PAES, we found preoperative DUS to have perfect agreement with the intraoperative findings in diagnosing PAES. The applicability of the method seems to be emphasized by the restoration of popliteal flow and relief of arterial insufficiency after surgical release in all patients, and by the fact, that none of the healthy volunteers were able to compress the popliteal artery during plantar flexion.

Lower limb vascular dysfunction in cyclists

Sports-related vascular insufficiency affecting the lower limbs is uncommon, and early signs and symptoms can be confused with musculoskeletal injuries. This is also the case among professional cyclists, who are always at the threshold between endurance and excess training. The aim of this review was to analyze the occurrence of vascular disorders in the lower limbs of cyclists and to discuss possible etiologies. Eighty-five texts, including papers and books, published from 1950 to 2012, were used. According to the literature reviewed, some cyclists receive a late diagnosis of vascular dysfunction due to a lack of familiarity of the medical team with this type of dysfunction. Data revealed that a reduced blood flow in the external iliac artery, especially on the left, is much more common than in the femoral and popliteal arteries, and that vascular impairment is responsible for the occurrence of early fatigue and reduced performance in cycling.

Between a rock and a hard place: clinical and imaging features of vascular compression syndromes

Vascular compression syndromes are caused by the entrapment of vessels between rigid or semirigid surfaces in a confined anatomic space. Chronic entrapment may lead to arterial ischemia and embolism, venous stasis and thrombosis, and hematuria. These syndromes are usually seen in otherwise healthy young patients, among whom underdiagnosis is common. Most occurrences of vascular compression are associated with an underlying anatomic abnormality. In a small percentage of cases, other contributing factors, including repetitive microtrauma, may cause pathologic changes leading to the onset of pain and other symptoms of vascular and neural compression. Hence, the diagnosis must be based on both clinical and radiologic findings. Because some cases of vascular entrapment become symptomatic only when specific physical maneuvers are performed, dynamic diagnostic imaging methods are especially useful. Digital subtraction angiography has been the mainstay of imaging-based diagnosis for most vascular compression syndromes, but other methods (eg, color Doppler ultrasonography, computed tomographic angiography, and magnetic resonance angiography) are used with increasing frequency for initial diagnostic evaluation. Because vascular compression syndromes are caused by the external compression of vessels, endoluminal treatment alone is rarely adequate and surgical decompression is likely to be required for optimal and durable clinical benefit. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.321115011/-/DC1.

Endovascular management of the popliteal artery: comparison of atherectomy and angioplasty

PURPOSE

Symptomatic atherosclerotic disease of the popliteal artery presents challenges for endovascular therapy. We evaluated the technical success, complications, and midterm outcomes of atherectomy and angioplasty involving the popliteal segment.

METHODS

We conducted a retrospective review of outcomes of popliteal artery intervention using atherectomy or angioplasty performed between 2003 and 2008.

RESULTS

A total of 56 patients (36% women, age 72.8 +/- 12.2 years, 77% critical limb ischemia) underwent popliteal atherectomy (n = 18) or angioplasty (n = 38). These patients had similar clinical characteristics, TransAtlantic Intersociety Consensus (TASC)/ TASC II classification, mean lesion length, and runoff scores. We observed a trend toward higher rates of technical success defined as <30% residual stenosis after atherectomy compared to angioplasty (94% vs 71%, P = .08). While angioplasty was associated with a higher frequency of arterial dissection (23% vs 0%, P = .003), atherectomy was associated with a higher rate of thromboembolic events (22% vs 0%, P = 0.01). Adjunctive stenting was used more frequently following angioplasty compared to atherectomy (45% vs 6%, P = .005). Thrombolysis was used to treat embolization in 4 patients in the atherectomy group. The improvement in the ankle-brachial index (ABI) was similar between the 2 treatment groups. Primary patency of the popliteal artery at 3, 6, and 12 months was 94%, 88%, and 75% in the atherectomy group and 89%, 82%, and 73% in the angioplasty group (P = not significant [NS]). There were no significant differences in limb salvage and freedom from reintervention at 1 year between the atherectomy and angioplasty groups.

CONCLUSIONS

Our experience with popliteal artery endovascular therapy indicates a distinct pattern of procedural complications with atherectomy compared to angioplasty but similar midterm patency, limb salvage, and freedom from intervention.

Entrapment syndromes

Entrapment syndromes represent a pathological process that vascular specialists encounter infrequently. However symptomatic patients are often young with impaired quality of life and successful treatment can produce great benefit, making knowledge of these conditions essential. The purpose of this review was to bring together the entrapment syndromes to understand and gain consensus on the aetiology, pathogenesis, diagnosis and modern management of these rare and interesting vascular disorders. This includes entrapment syndromes of the popliteal artery, superior mesenteric artery, coeliac artery, renal vein and iliac vein.

Assessment of the medial head of the gastrocnemius muscle in functional compression of the popliteal artery

OBJECTIVE

Nonfunctional popliteal entrapment is due to embryologic maldevelopment within the popliteal fossa. Functional entrapment occurs in the apparent absence of an anatomic abnormality. Gastrocnemius hypertrophy has been associated with the latter. Both forms of entrapment may cause arterial injury and lower limb ischemia. This study assessed the attachment of the medial head of the gastrocnemius muscle in healthy occluders and healthy nonoccluders.

METHODS

Provocative tests were used to identify 58 nonoccluders and 16 occluders. Ten subjects from each group underwent magnetic resonance imaging evaluation of the popliteal fossa. The medial head of the gastrocnemius muscle attachment was assessed in the supracondylar, pericondylar, and intercondylar areas.

RESULTS

In the occluder group, significantly more muscle was attached towards the femoral midline (supracondylar), around the lateral border of the medial condyle (pericondylar), and within the intercondylar fossa.

CONCLUSION

The more extensive midline position of the medial head of the gastrocnemius in occluders is likely to be a normal embryological variation. Forceful contraction results in compression and occlusion of the adjacent popliteal artery. The clinical significance of these anatomic variations remains unclear. However, these new observations may provide insight for future analysis of the causes and natural history of functional compression and the potential progression to clinical entrapment.

Arteriographic evidence of pseudoocclusion of the popliteal artery: don't be fooled

Individuals with chronic lower extremity pain or lifestyle limiting claudication often undergo angiography prior to intervention. Occasionally initial angiographic findings are not indicative of a true pathologic process. Described below are two such cases. Both of the patients described had iliofemoral atherosclerotic disease with arteriographic suggestion of popliteal artery occlusion. However, their medical histories, noninvasive vascular studies, and arteriograms were not consistent with chronic popliteal artery occlusion. On subsequent arteriogram with knee flexion, the occlusions were found to be positional or pseudooccluded. Pseudoocclusion of the popliteal artery (POPA) does not require intervention, and therefore it is necessary to differentiate it from other pathologic processes. Discrimination of POPA from atherosclerotic occlusion, popliteal artery entrapment syndrome, cystic adventitial disease, and vasculitis is possible through history and exam. Arteriography is helpful because a lack of contralateral disease or collateral circulation may indicate a positional occlusion.

ENDOVASCULAR REPAIR OF POPLITEAL ARTERY ANEURYSMS: TECHNIQUES, CURRENT EVIDENCE AND RECENT EXPERIENCE

Endovascular repair of popliteal artery aneurysms is a new technique, which has emerged as an alternative to open surgical bypass. However, evidence to support its use is limited. We present a review of current literature relevant to this technique. The MEDLINE search terms were popliteal artery, aneurysm, endovascular, endoluminal and stent. Fifty-eight articles were yielded, of which 21 were studies of endovascular repair by implantation of stent or stent graft of true aneurysms of the popliteal artery. There was only one randomized study. Small numbers of endovascular interventions are reported, with variations in study design and endovascular techniques. Long-term follow-up data is lacking; however, early results have been promising with high rates of initial treatment success. Early thrombosis of stent grafts occurs in approximately 10%, but this does not herald limb loss. Endovascular treatment offers potential benefits over traditional surgery, but needs to be studied further with a large-scale multicentre randomized trial.

Diagnosis and surgical management of popliteal artery entrapment syndrome

BACKGROUND

The purpose of the present study was to report the authors' experience of surgically treating eight limbs in six patients for popliteal artery entrapment syndrome (PAES), over a 10-year period.

METHODS

From 1995 to 2004, six patients (eight limbs) underwent surgery for PAES at a single institution. The patients' data were collected retrospectively from the case records and operative notes.

RESULTS

There were six patients with a mean age of 34 years (range, 27-38 years) at diagnosis and five of them were male. Two patients were found to have bilateral involvement. Both patients had symptoms involving both limbs and underwent bilateral surgery. Intermittent claudication was the most frequent presenting symptom (seven of eight limbs). All the patients had Delaney's type III PAES. Popliteal artery release was performed in all eight limbs and this was combined with a vein patch or a reversed long saphenous vein bypass graft in four limbs because the arteries in these four limbs were diseased or occluded. At a median follow up of 15 months (range, 40 days-9 years), five (seven limbs) of the six patients (eight limbs) were cured of their symptoms. One patient who presented late with rest pain and dusky toes underwent popliteal artery release, endarterectomy and a vein patch repair for an occluded popliteal artery. However, her limb could not be salvaged and her affected limb had to be amputated.

CONCLUSION

Popliteal artery entrapment syndrome is a rare but important cause of peripheral vascular insufficiency especially in young patients. Early diagnosis and surgical intervention is imperative for good operative outcome and to prevent limb loss.

Biomechanical Incompatibility of Popliteal Stent Placement

Peripheral stents or endografts in specific arterial segments are exposed to extreme mechanical stress. Despite high rates of primary technical success, mechanical bending due to knee joint flexion can limit long-term patency of stents or endografts in the popliteal artery or the femoropopliteal segment. Every stent or endograft responds differently to bending during knee joint flexion, which can be revealed only by functional investigation. Mechanical bending has to be considered in future studies to assess the influence of differences in stent design, material, or postinterventional drug treatment on the long-term patency of endoprostheses in the femoropopliteal segment. To demonstrate the concept of biomechanical incompatibility, we present several illustrations of different stent designs placed in the popliteal artery.

Non-traumatic lower limb vascular complications in endurance athletes. Review of literature

OBJECTIVES

To review the importance, clinical features, investigations, management and prognosis of non-traumatic vascular injuries, affecting the lower limbs of endurance athletes.

DESIGN

Review of literature.

MATERIALS AND METHODS

A literature search was conducted from Medline, Pubmed, the National Electronic Library for Health, Google and Yahoo search engines for related articles and case reports regarding non-traumatic vascular complications involving the lower limb of endurance athletes.

CONCLUSIONS

Non-traumatic vascular complications affecting the lower limbs include endofibrosis, stenosis/kinking of iliac arteries, dissection of external iliac artery, adductor canal syndrome, popliteal entrapment syndrome, chronic exertional compartment syndrome and effort-induced venous thrombosis. These are important as they affect athletes at the peak of their career and can be confusing to diagnose. The management is relatively well documented and produces good results in short term but the long term results are not known.

Results of perioperative measurements of ankle-brachial index in popliteal artery entrapment syndrome

OBJECTIVE

The purpose of this study was to demonstrate whether there is postoperative improvement in blood flow in the affected limb after surgical decompression in popliteal artery entrapment syndrome (PAES). For this purpose, the simple method of measuring Doppler ankle pressure with and without provocation was used preoperatively and postoperatively.

PATIENTS AND METHODS

Doppler ankle pressure was measured preoperatively and postoperatively in neutral position (n=32) and with provocation (forced plantar flexion of the foot; n=32) in 32 limbs in 23 patients with PAES (19 men, 4 women; average age, 38.24 +/- 12.25 years) operated on between January 1, 1986, and December 31, 2000. The reference method was angiography with provocation in 18 patients and duplex ultrasound scanning in 14 patients.

RESULTS

Patients were assigned to one of two groups (A and B) on the basis of ankle-brachial index (ABI) at rest. Group A (mean age, 38.19 +/- 11.60 years) included all limbs (n=24) with ABI>0.9 preoperatively, and group B (mean age, 42.39 +/- 14.38 years) comprised all limbs (n=8) with ABI<0.9. Improvement in ABI under provocation after operation (group A, P<.0001; group B, P<.0004) was highly significant. In group B there was also a highly significant difference in ABI in the neutral position before and after operation (P=.0044); this could not be demonstrated in group A. Angiography or duplex sonography postoperatively did not provide any additional information.

CONCLUSION

Our results indicate that determination of ABI alone, with and without provocation, is sufficient as a postoperative follow-up examination to appraise decompression and for quality assurance of PAES. Compared with other more elaborate instrumental methods, measurement of ABI is relatively noninvasive, quick and easy to carry out, effective, and inexpensive.

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome is a condition caused by direct compression of the popliteal artery as it passes within or exits the popliteal fossa. It is surprisingly uncommon and usually affects young patients, typically men, and often presenting with symptoms of claudication, or more rarely acute limb ischemia, calf cramps, or a picture of compartment syndrome. The diagnosis should be considered early within the differential diagnosis of all patients presenting with these problems in this age group. The key to management of this condition lies in a high index of suspicion. The treatment of popliteal artery entrapment syndrome is surgical. When the condition is detected at an early stage surgery may be limited to release of the artery alone. However, if the artery has been compressed for some time the resulting intimal damage necessitates bypass of the affected segment. There are numerous reports of thrombectomy with simple vein patching, but the results are inferior to interpositional vein grafting. Reports have also been published of attempts made at endovascular treatment. At present, this mode of management adds little to the definitive treatment of affected limbs and appears limited to use as a bridging procedure in cases presenting with limb ischemia. Unfortunately, an effective clinical screening test does not exist and imaging remains the mainstay in the diagnosis of symptomatic limbs and the screening of asymptomatic limbs. The exact modality of imaging remains unclear, but for the moment duplex scanning, angiography, computed tomography, and magnetic resonance imaging all appear to have their place.

Popliteal artery entrapment syndrome

BACKGROUND

Popliteal artery entrapment syndrome (PAES) is rare and may be underdiagnosed. Improved specialized, non-invasive imaging techniques are producing detailed topographical evidence of the anomaly.

METHODS

A historical review of the literature and Medline search was performed with reference to the diagnosis and treatment of the condition. In addition, embryologically based theories for the condition have been postulated.

RESULTS AND CONCLUSION

PAES may be the result of abnormal development of the popliteal artery or a consequence of excessive cranial migration of the medial head of the gastrocnemius muscle. Magnetic resonance imaging appears to be the most useful single investigation to demonstrate the anomaly. Popliteal artery release alone or with vein bypass is the treatment of choice when intervention is indicated.

Functional popliteal entrapment syndrome

BACKGROUND

Classic popliteal artery entrapment is caused by the abnormal relationship between the popliteal artery and the medial head of the gastrocnemius, resulting in repetitive arterial compression and trauma. There is, however, a distinct subset of calf claudicants who have an anatomically normal popliteal fossa but can occlude the popliteal artery by repetitive vigorous exercise which involves active plantar flexion with or without extension at the knee joint.

METHODS

Eight patients who led a vigorous athletic lifestyle were evaluated with duplex scan and biplane angiogram after being referred for bilateral calf claudication. They were found to have significant stenosis or occlusion of the popliteal artery with active plantar flexion. All patients had transection of the medial head of the gastrocnemius muscle with release of any vascular bands tethering the popliteal artery.

RESULTS

Seven of the eight patients had complete relief. One patient noticed return of claudication at long distances, but a postoperative angiogram was normal. In all patients postoperative duplex scan showed no stenosis or occlusion of the popliteal vessels with the foot in active plantar flexion and the knee in extension.

CONCLUSIONS

Functional popliteal artery entrapment is becoming a significant cause of disabling claudication in young athletic individuals and needs to be diagnosed accurately for appropriate treatment. This condition is becoming well known with the incorporation of sports in the daily routine of most young people.