Aneurysm, Popliteal Artery


Article Author:
Mohammed Kassem


Article Editor:
Lorena Gonzalez


Editors In Chief:
Anne Kennedy


Managing Editors:
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Frank Smeeks
Kristina Soman-Faulkner
Benjamin Eovaldi
Radia Jamil
Sobhan Daneshfar
Pritesh Sheth
Hassam Zulfiqar
Steve Bhimji
John Shell
Matthew Varacallo
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Hajira Basit
Phillip Hynes
Kavin Sugumar


Updated:
11/22/2018 8:26:32 PM

Introduction

The popliteal artery is defined as aneurysmal when focal dilation in its diameter is more than 50% of the normal vessel diameter. The normal diameter of the popliteal artery varies between 0.7 to 1.1 cm. These focal dilations are classified as fusiform (diffuse dilation) or saccular  (asymmetrical). Popliteal artery aneurysms (PPAs) account for 85% of all peripheral aneurysms. PAAs are associated with abdominal aortic aneurysms 40% to 50% of the time.[1][2][3]

The popliteal artery is considered a continuation of the superficial femoral artery after it passes through the adductor magnus hiatus. It lies in the popliteal fossa accompanying its vein and terminates at the bifurcation into the anterior tibial artery and tibioperoneal trunk, which is located at the lower border of the popliteus muscle at the level of the tibial tuberosity.

Etiology

Modifiable risk factors include smoking, atherosclerosis, connective tissue disorders such as Marfan syndrome,  and Ehler-Danlos syndrome. Non-modifiable risk factors include advanced age, male gender, Caucasian race, and family history of an aneurysmal disease.[4][2]

Epidemiology

The exact incidence of popliteal artery aneurysm is not known as no population-based study has been published; however, a few series studies issued by different institutions suggest that PPA's prevalence increases with age and peaks in the sixth or seventh decades of life. The incidence of femoral and popliteal aneurysms in persons with abdominal aortic aneurysms (AAA) appears higher than the general population. In one study of 225 patients, 28% (n=63) had a PAAs greater than or equal to 10.5 mm, 19% (n=43) had a PAAs greater than or equal to 12mm and 11% (n=25) had a PAAs greater than or equal to 15mm.

Pathophysiology

The etiology of PAAs and aneurysms, in general, is unknown. Molecular studies suggest that a combination of genetic defects and inflammatory processes may be responsible. Atherosclerosis tends to increase flow turbulence distal to a stenosis, leading to a pathological dilation of the artery. Decreased wall strength associated with inflammatory cell infiltration is believed to result in aneurysm formation.[5]

History and Physical

Most commonly PPAs are asymptomatic. If patients exhibit chronic symptoms, these are usually secondary to mass effect and compression of adjacent structures, such as the tibial nerve, which cause leg pain or paresthesias. The popliteal vein also may be compressed which causes calf swelling. Progressive luminal narrowing of the popliteal artery from thrombus formation may cause an insidious onset of claudication. Approximately 50% of the patients present with bilateral aneurysms.

When an aneurysm acutely thromboses, the most common symptoms are acute lower extremity ischemia resulting in the acute onset of pain, paresthesias, paresis, pallor and poikilothermia due to either aneurysmal intraluminal thrombosis or distal embolization of thrombus. Distal embolization can be manifested by the blue toe syndrome and/or acral cyanosis.

Approximately 30% of untreated patients experience acute thrombosis and distal embolization with the risk of possible limb loss. Patients who develop acute thrombosis or embolism have a relatively poor prognosis with a 15% amputation rate due to occlusion of runoff vessels.

The popliteal fossa should be examined bilaterally with the knee in a semi-flexed position. About 60% of patients with popliteal aneurysms have a palpable pulsatile mass at the level of the knee joint.

Evaluation

Duplex ultrasonography (US) is the ideal screening and diagnostic imaging modality to detect a PPA and estimate its diameter. The US also provides detailed information regarding vessel patency, development of mural thrombus, and the status of outflow vessels. CT or magnetic resonance (MR) angiography are other alternatives to duplex ultrasonography and can accurately measure true lumen diameters as well as assist in the planning of operative repair. Conventional angiography is reserved for either elective endovascular repair of an aneurysm or in cases of threatening acute limb ischemia for initiation of thrombolytic therapy.[6][7][8]

Treatment / Management

All symptomatic popliteal artery aneurysms should be repaired because of increased incidence of thrombosis or limb loss. Asymptomatic aneurysms with a diameter greater than 2 cm are considered an indication for an elective operation to avoid complications such as limb-threatening ischemia. Greater than 45 angulation in asymptomatic aneurysms warrants surgical intervention because they can produce acute limb ischemia secondary to kinking of the vessel.[9][10][6]

Conservative Management 

Asymptomatic aneurysms less than 2 cm can be safely managed via duplex surveillance.

Open Surgical Approach

Traditional open surgery involves ligation of the popliteal artery proximal (above the knee) and distal (below the knee) below the aneurysmal sac and bypassing the excluded segment using either reversed autologous vein graft (saphenous vein) or prosthetic graft. An alternative surgical approach is aneurysmectomy followed by interposition bypass with a prosthetic graft between the proximal and distal normal segments of the popliteal artery. However, the former approach is more common.

Endovascular Approach

Recently, endovascular techniques have gained popularity in PAA repair as an alternative to the open surgical approach. This is achieved via exclusion of the aneurysmal sac with a stent graft implantation. Recent studies show that popliteal artery stenting is a safe alternative technique for the treatment of PAAs, especially in high-risk patients. Advantages to endovascular technique include a shorter hospital stay and an abbreviated operative time when compared to open surgical intervention. Disadvantages include higher 30-day graft thrombosis rates (9% in the endovascular treatment group versus 2% in the open surgical treatment group) and higher 30-day re-intervention rates (9% in the endovascular treatment group versus 4% in the open surgical treatment group). There is no significant difference regarding the incidence of mortality or limb loss rates between the two repair groups.

Management of Acutely Thrombosed Aneurysms

Management of this will vary according to the presentation. Asymptomatic patients with completely thrombosed popliteal artery aneurysms and those who are non-ambulatory patients or have acutely thrombosed aneurysms with a poor runoff despite thrombolysis are not candidates for surgical intervention. Only patients with disabling symptoms or critical limb ischemia are treated with surgical bypass as the first line of therapy. Patients presenting with acute limb-threatening ischemia should be bypassed urgently. Acute thrombosis should be treated with intravenous heparin and continuous heparin infusion to limit the extension of thrombus. However, some surgeons advise that threatening ischemia is better treated with thrombectomy followed by bypass surgery.

Intra-arterial Thrombolytic Therapy

This is indicated when angiography demonstrates no target vessel or multiple distal thrombi are noted.

Differential Diagnosis

  • Baker's cyst
  • Lymph node
  • Varicosity
  • Cystic adventitial disease

Complications

Limb loss

Pearls and Other Issues

The differential diagnosis of popliteal fossa masses includes both arterial and non-arterial pathologies as well as popliteal artery aneurysms. Rare popliteal artery pathology most commonly located in the behind the knee includes cystic adventitial disease and the popliteal entrapment syndrome. Both conditions usually present with chronic symptoms of claudication. However, the most common cause of a popliteal fossa mass is the Baker cyst which is a benign swelling of the semimembranosus, or more rarely some other synovial bursa, found behind the knee joint. Orthopedic causes include prepatellar bursitis and meniscal cysts.

 

 

Enhancing Healthcare Team Outcomes

Popliteal artery aneurysms are usually managed by a team of healthcare professionals that include a vascular surgeon, an interventional radiologist, endocrinologist, an internist and a critical care specialist. While elective management of these aneurysms yields good results, patients who present with a rupture, frequently end up losing their limb. In view of the very high risk of losing a limb following rupture of a popliteal artery aneurysm, patient education is vital. The nurse plays a vital role in monitoring and educating patients with a popliteal artery aneurysm. The patient must be educated that once a diagnosis of an aneurysm is made, he should follow up with a vascular surgeon and undergo elective surgery or have an endovascular procedure performed. More important, the patient must stop smoking, manage the high blood pressure and control blood sugars. Finally, it is important to examine the patient for a popliteal artery aneurysm in the contralateral leg and abdomen. All patients with pulsatile mass behind the knee should be referred to the radiologist for an ultrasound. [11][12][13](Level V)

Outcomes

For patients who have the popliteal artery aneurysm repaired electively the prognosis is good. In fact, outcomes with both surgery and an endovascular procedure appear to be similar in the short term. However, the long-term outcome of an endovascular procedure on the popliteal artery aneurysm remains unknown. In patients who present with rupture of a popliteal artery aneurysm, the outcome is usually poor. Limb loss is common. The amputations may be above or below the knee. The only way to reduce these poor outcomes and is by thoroughly examining the pulses in all patients.[14][15][16] (Level III)


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Aneurysm, Popliteal Artery - Questions

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A patient has been told that he has a mass behind the left knee. Ultrasound reveals that it is a soft pulsatile mass. What will be the next most common site of a similar mass?



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A 66-year-old is found to have a large pulsatile mass in the left popliteal fossa. He has no symptoms. Which of the following statements about this condition is true?



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A 56-year-old male is incidentally found to have a 2 cm right popliteal artery aneurysm, that was found on duplex ultrasound to rule out a deep venous thrombosis. Which of the following is the most common complication associated with popliteal artery aneurysms?



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A 48-year-old male smoker over the past few months has developed mild varicosities in the thigh area. While examining the distal extremities, you palpate a 3 x 2 cm pulsatile mass behind the right knee. How does this mass usually present clinically?



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An 89-year-old female with extensive coronary artery disease with coronary artery bypass graft in the past, chronic obstructive pulmonary disease on home oxygen, and stage IV lung cancer. On exam, she was found to have a 4 cm popliteal aneurysm. What is the appropriate management for this patient?



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Aneurysm, Popliteal Artery - References

References

Shiwani H,Baxter P,Taylor E,Bailey MA,Scott DJA, Modelling the growth of popliteal artery aneurysms. The British journal of surgery. 2018 Aug 23     [PubMed]
Cecenarro RR,Allende JN,Barreras Molinelli L,Antueno FJ,Gramática L, [Popliteal Artery Aneurysms: Literature Review and presentation of case.] Revista de la Facultad de Ciencias Medicas (Cordoba, Argentina). 2018 Mar 29     [PubMed]
Cervin A,Ravn H,Björck M, Ruptured popliteal artery aneurysm. The British journal of surgery. 2018 Jul 24     [PubMed]
Mikhaylov IP,Lavrenov VN,Isaev GA,Kokov LS,Trofimova EY, [Ruptures of popliteal artery aneurysms]. Khirurgiia. 2018     [PubMed]
Fioranelli A,Carpentieri EA,Wolosker N,Castelli V Jr,Caffaro RA, Rupture of Thrombosed Popliteal Aneurysm: A Case Report. Annals of vascular surgery. 2018 Aug     [PubMed]
Golchehr B,Zeebregts CJ,Reijnen MMPJ,Tielliu IFJ, Long-term outcome of endovascular popliteal artery aneurysm repair. Journal of vascular surgery. 2018 Jun     [PubMed]
Cousins RS,Dexter DJ,Ahanchi SS,Cain BC,Powell OM,Ongstad SB,Parikh NM,Panneton JM, Determining patient risk factors associated with accelerated growth of popliteal artery aneurysms. Journal of vascular surgery. 2018 Mar     [PubMed]
Ravn H,Pansell-Fawcett K,Björck M, Popliteal Artery Aneurysm in Women. European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. 2017 Dec     [PubMed]
Kim SM,Jung IM, Successful endovascular treatment of a ruptured popliteal artery aneurysm in a patient with Behcet disease. Annals of vascular surgery. 2018 Aug 6     [PubMed]
Ucci A,Curci R,Azzarone M,Bianchini Massoni C,Bozzani A,Marcato C,Marone EM,Perini P,Tecchio T,Freyrie A,Argenteri A, Early and mid-term results in the endovascular treatment of popliteal aneurysms with the multilayer flow modulator. Vascular. 2018 Jan 1     [PubMed]
Kaufman RL, Popliteal aneurysm as a cause of leg pain in a geriatric patient. Journal of manipulative and physiological therapeutics. 2004 Jul-Aug     [PubMed]
Fargion A,Masciello F,Pratesi G,Giacomelli E,Dorigo W,Pratesi C, Endovascular Treatment with Primary Stenting of Acutely Thrombosed Popliteal Artery Aneurysms. Annals of vascular surgery. 2017 Oct     [PubMed]
Lee TL,Bokovoy J, Understanding discharge instructions after vascular surgery: an observational study. Journal of vascular nursing : official publication of the Society for Peripheral Vascular Nursing. 2005 Mar     [PubMed]
Salzler GG,Long B,Avgerinos ED,Chaer RA,Leers S,Hager E,Makaroun MS,Eslami MH, Contemporary Results of Surgical Management of Peripheral Mycotic Aneurysms. Annals of vascular surgery. 2018 Jun 8     [PubMed]
Wrede A,Wiberg F,Acosta S, Increasing the Elective Endovascular to Open Repair Ratio of Popliteal Artery Aneurysm. Vascular and endovascular surgery. 2018 Feb     [PubMed]
Leake AE,Segal MA,Chaer RA,Eslami MH,Al-Khoury G,Makaroun MS,Avgerinos ED, Meta-analysis of open and endovascular repair of popliteal artery aneurysms. Journal of vascular surgery. 2017 Jan     [PubMed]

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