Treatment of Popliteal Aneurysms by Femoral Artery Transposition: Long-term Evaluation
Article Outline
A multicentric retrospective study was carried out on 29 operations (28 patients) to evaluate the long-term results of the treatment of popliteal artery aneurysms by transposition of the superficial femoral artery (SFA). This treatment consisted in proximal and distal ligation and bypass grafting or endoaneurysmorrhaphy followed by reconstruction of the popliteal artery. This surgery was always performed when the homolateral SFA could be used. After surgery, every patient was prescribed a long-term antiplatelet treatment. Mean follow-up was 39.2
±28 months. Actuarial primary patency was 100% at 1 year and 92% at 3 years. No patients presented with either aneurysmal evolution of arterial graft or septic complication of prosthetic bypass. SFA can be used to treat isolated popliteal aneurysms with satisfying long-term results. This technique is an alternative to the use of autologous saphenous vein.
Introduction
Popliteal artery aneurysms (PAAs) are rare, with a prevalence of 1% in men aged between 65 and 80.1 They represent about 70% of peripheral aneurysms.2 Most of them have an atherosclerotic origin but they also can be mycotic or part of a Marfan syndrome or a Behçet disease.
The first objective of surgical treatment is to prevent thromboembolic events with limb ischemia and tissue loss complications. The second objective is to prevent them to increase in volume, which can cause compressive phenomena and even, but exceptionally, ruptures. Surgical treatment of isolated popliteal aneurysms may be either exclusion or endoaneurysmorrhaphy in association with bypass.
Recently some authors have proposed endovascular treatment with covered stents. The most common operation is exclusion and bypass with saphenous vein. Reix et al.3 have suggested the use of an autologous arterial graft with encouraging short-term results. The aim of our study was a long-term evaluation of superficial femoral artery transposition to treat isolated popliteal artery aneurysms.
Materials and Methods
Patients
This multicentric study about 29 consecutive operations performed to treat isolated PAA enroled 28 patients between March 1995 and August 2006. Seventeen operations were performed at the CHU in Lyon and 12 at the CHU in Poitiers. Transposition of homolateral superficial femoral artery was systematically chosen when this artery could be used to treat an isolated popliteal aneurysm. At the same time, 44 popliteal artery aneurysms were operated on at the CHU in Lyon and 21 at the CHU in Poitiers.
These operations were performed on 27 men (93%) and 2 women, with a mean age of 68±8.2 years (range, 50 to 86). Risk factors were the same as in any cardiovascular population. There were 16 smokers (55.2%), 22 hypertensive patients (75.9%), 14 patients with dyslipidemia (48.3%), and 5 patients with diabetes (17.2%) (Table I). Fourteen patients were asymptomatic (48.3%). Ten of those 15 symptomatic patients were presenting with claudication (34.5%), 3 patients had rest pain (10.3%), 1 patient had an acute ischemia (3.4%) resulting from thrombosis of the aneurysm, and 1 patient had a popliteal aneurysm rupture (3.4%).
Table I. Epidemiologic data
| Characteristic | n | % |
|---|---|---|
| Men | 27 | 93 |
| Women | 2 | 7 |
| Age (yr, SD) | 68±8.2 | |
| Active smokers | 16 | 55 |
| Hypertension | 22 | 75.9 |
| Hyperlipidemia | 14 | 48.3 |
| Diabetes | 5 | 17.2 |
| Asymptomatic | 14 | 48.3 |
| Symptomatic | 15 | 51.7 |
| Claudication | 10 | 34.5 |
| Rest pains | 3 | 10.3 |
| Acute ischemia | 1 | 3.4 |
| Rupture of the aneurysm | 1 | 3.4 |
| Patent leg arteries | ||
| 3 | 16 | 55.2 |
| 2 | 6 | 20.7 |
| 1 | 7 | 24.1 |
In every case, preoperative evaluation included duplex scan in association with peripheral arteriography and/or angio computed tomography (CT). Fifteen patients were evaluated only by arteriography (51.7%). Seven patients, including the one with aneurysmal rupture, underwent angio-CT alone (24.1%), and seven patients (24.1%) underwent both arteriography and angio-CT.
The patient with a popliteal aneurysm rupture was the only one to undergo an emergency surgery. The other patients underwent an elective surgery. The patient with from severe ischemia had a fibrinolysis before operation. The aneurysm and the leg arteries were repermeabilized, which enabled a delay of the operation. When they were operated on, 16 patients had three patent leg arteries (55.2%), 6 had two patent arteries (20.7%), and 7 had only one patent artery.
Surgery was decided for aneurysms with a diameter of 20mm or greater or with mural thrombosis. Mean diameter of the aneurysms was 31.4±9.2mm (range, 20 to 54mm). Nine patients had an associated abdominal aortic aneurysm (31%). Eleven patients had an associated iliac aneurysm (37.9%). Nine patients also had an associated aneurysm of the common femoral artery (31%), and 23 patients had an aneurysm of the controlateral popliteal artery (79.3%) (Table II).
Table II. Associated aneurysms
| Aneurysm | n | % |
|---|---|---|
| AAA | 9 | 31 |
| IAA | 11 | 37.9 |
| FAA | 9 | 31 |
| cPAA | 23 | 79.3 |
Surgical Technique
All PAAs were treated with transposition of a homolateral SFA autograft under general anesthesia. In 16 cases (55.2%), a classic approach was used with upper and lower popliteal artery exposure, which enabled control of the proximal and distal necks of the aneurysm. Then, surgery consisted of exclusion and a bypass.
In 13 cases (44.8%), patients were positioned in lateral decubitus opposite to the operated limb, keeping their leg free, which allowed a posterior approach to the PAA. An arterial bypass was then performed. After systemic heparinization, a sufficient length of the homolateral SFA was taken. The arterial graft was placed in anatomic position with end-to-end anastomoses. The transposed superficial femoral artery was replaced with a PTFE or polyester graft, with end-to-end anastomoses. A PTFE prosthesis was used in 22 cases (75.9%). In 7 patients (24.1%), a polyester prosthesis was used.
A 10-mm-diameter prosthesis was used in nine patients (31%). One patient received a 9-mm-diameter prosthesis, 15 patients (51.7%) received a 7-mm-diameter prosthesis, and 4 patients (13.9%) received a 7-mm-diameter prosthesis. Completion arteriography was routinely performed. Whenever a long segment of superficial femoral artery was transposed, an end-to-end anastamosis could be done between the femoral graft and the prosthesis.
After surgery, the patients were given antiplatelet agents. Clinical and duplex follow-up was carried out at 1, 6, and 12 months and then once a year.
Statistical Analysis
Information about patients was prospectively entered into a database. Results are presented as mean ± standard deviation. Short- and long-term actuarial patency rates were calculated according to the Kaplan-Meier method.
Results
Surgery was elective in 93.1% of the cases. No postoperative mortality was observed. There were no immediate postoperative amputations and no patients had a delay in healing. They were all ambulatory at hospital discharge. The postoperative lenght of stay in the hospital was 7.2 days (range, 6 to 10 days). At 30 days, no additional procedures were necessary. The mean follow-up period was 39.2±28 months (median, 31 months; range, 1 to 114 months), without amputations. No aneurysmal evolution of the transposed superficial femoral artery was observed. No patients had graft infection.
Six patients died during the follow-up–two from myocardial infarctions, two from cancer, one from a cerebrovascular accident, and one from an unknown cause. Two patients (6.9%) had a prosthetic bypass occlusion despite a patent transposed femoral artery. The first thrombosis occurred after 29 months following a complete hip replacement as anticoagulant treatment had been stopped. This patient had 10-mm-diameter Dacron prosthesis. Thrombectomy with a Fogarty balloon was successfully performed. A second thrombosis happened at 50 months. This patient was not reoperated because he was asymptomatic and not healthy. He had a 10-mm-diameter PTFE prosthesis. One patient (3.4%) developed a stenosis at the level of the proximal anastamosis of the superficial femoral artery at 27 months. This stenosis was efficiently treated with transluminal angioplasty. Primary actuarial patency rates were 100% at 1 year and 92% at 3 years, respectively (Fig. 1). Secondary actuarial patency was 100% at 1 and 3 years.
Fig. 1
Perméabilité actuarielle primaire de l'étude.
Discussion
The surgical treatment of PAAs with a diameter 20mm or greater or with mural thrombus is currently well established. With transposition of the superficial femoral artery, we observed a 92% primary patency rate and a 100% secondary patency rate at 3 years. We had no major postoperative complications. Michaels and Galland4 demonstrated that, in case of conservative treatment, PAAs became asymptomatic in 14% of the cases after 1 year. For Dawson et al.,5 the risk was 24% after 1 year and 74% after 5 years. Of 67 PAA conservative treatments, Lowell et al.6 discovered that 18% of the patients were symptomatic within 17 months. With surgical treatment, Michaels and Galland4 reported short-term death and amputation rates of 0.4% and 0.8%, respectively, for asymptomatic PAAs versus 4.7% and 18.2%, respectively, for symptomatic PAAs.
Moreover, Dawson et al.5 reported 10-year limb salvage rates of 100% and 60% after elective surgery and emergency surgery, respectively (p<0.01). In case of elective surgery, at 5 years, Lilly et al.7 found a 91% permeability rate versus a 54% rate in case of emergency surgery (p<0.05). In addition, Shortell et al.9 demonstrated that, unlike surgery for femoropopliteal occlusive lesions, in case of bypass thrombosis after 1 month, the number of saved limbs does not decrease, which suggests that a wait-and-see attitude leads to a greater number of amputations than elective surgery.
Our epidemiologic data are consistent with the literature (Table III). However, the limitations of this study are its retrospective nature and the small number of patients involved. Moreover, not all the aneurysms were treated in the same way because not all the patients benefited from endoaneurysmorrhaphy: 16 patients underwent exclusion and bypass. It is well known that isolated exclusion may result in an aneurysm that is still fed by collaterals and still growing. This is a type II endoleak equivalent that may be responsible for venous or neurologic compression or even for a rupture of the aneurysm still in place.
Table III. Epidemiologic data in the literature
| Lead author | Men | Age (yr) | Asymptomatic | Smokers | AHT | Hyperlipidemia | Diabetes | AAA | FAA | cPAA |
|---|---|---|---|---|---|---|---|---|---|---|
| Huang2 | 97% | 70 | 40% | 28% | 66% | 16% | 54% | 20% | 54% | |
| Lilly7 | 100% | 65 | 54% | 43% | 60% | 20% | 23% | 14% | 69% | |
| Shortell8 | 100% | 63 | 29.4% | 39% | 10% | 39% | 14% | 24% | ||
| Ebaugh9 | 94% | 63 | 52% | 56% | 67% | 17% | 6% | 44% | 28% | 72% |
| Pulli12 | 95% | 68 | 42% | 70.8% | 54.7% | 44.5% | 6.6% | 30.6% | 16% | |
| Beseth13 | 100% | 67 | 54.2% | 58% | 42% | 33% | 4% | 54% | 16.6% | 75% |
| Current study | 93% | 68 | 48.3% | 55% | 75.9% | 48.3% | 17.2% | 31% | 31% | 79.3% |
In a retrospective study on 57 exclusion and bypass grafting cases, Ebaugh et al.9 have found 32% popliteal aneurysms that kept on growing. In a recent study on 358 PAA operations, Huang et al.2 found a 2% redo surgery rate. Reoperation was only needed in patients who underwent exclusion and bypass. None of the patients who had endoaneurysmorrhaphy and bypass had to be operated on again. In our study, however, none of the patients who underwent exclusion and bypass presented with a volume increase of an aneurysm still in place. In our series, 44.8% of the cases have been treated with a posterior approach, whereas a medial approach was used in the other patients. Surgeons often prefer the medial approach because it is easier and enables saphenous harvest in case of venous bypass. However, to allow endoaneurysmorrhaphy, it requires the section of the muscles of the pes anserinus. In our study, the most recent operations were endoaneurysmorrhaphies with bypass and we did choose a posterior approach to reach the aneurysm.
The most frequently used technique to treat PAAs is exclusion and bypass. Many studies have demonstrated the advantages of venous bypass over prosthetic bypass. Bourriez et al.10 reported a patency rate of 94% at 2 years after venous bypass versus 62% after prosthetic bypass. Anton et al.11 found a 94% of patency rate at 10 years in case of venous bypass versus 27% in case of prosthetic bypass.
At 5 years, with a majority of prosthetic bypasses, Pulli et al.12 observed a 66.3% patency rate. At 10 years, with venous bypasses, Dawson et al.5 observed an 84% patency rate versus 41% with prosthetic bypasses. Recently, Hunag et al.2 confirmed these data with 85% of patency at 5 years with venous bypasses versus 50% with PTFE bypasses.
However, with the use of prosthetic bypasses that were performed with a posterior approach, Beseth and Moore13 found a good 92.2% patency rate at 2 years. Reix et al.3 were the first to publish short-term results of an 18-patient series of treatment by homolateral superficial femoral artery autograft.
In our series, primary patency rate at 3 years was 92%. This result is consistent with the 91% primary patency rate at 22 months found by Reix et al.3 and it can be compared with the above-mentioned venous bypass patency rates; this patency rate is higher than with prosthetic bypasses (Table IV).
Table IV. Patency in different studies
| Lead author (year) | No. of patients | Material | Patency (%) | Follow-up (yr) |
|---|---|---|---|---|
| Anton11 (1986) | 58 | Vein | 94 | 10 |
| 39 | PTFE, polyester | 27 | 10 | |
| 25 | Vein | |||
| Dawson5 (1991) | 17 | Polyester | 84 | 10 |
| 41 | 10 | |||
| Reix3 (2000) | 18 | SFA | 91 | 2 |
| Bourriez10 (2005) | 80 | Vein | 94.3 | 2 |
| 20 | Prosthesis | 61.5 | 2 | |
| Pulli12 (2006) | 118 | Prosthesis | 66.3 | 5 |
| Beseth13 (2006) | 30 | PTFE, polyester | 92.2 | 2 |
| Huang2 (2007) | 259 | Vein | 85 | 5 |
| 97 | PTFE | 50 | 5 | |
| Lemonnier | 29 | SFA | 92 | 3 |
In our study, we have not noticed any aneurysmal evolution of the SFA graft, unlike Szilagyi et al.,14 who reported 3.8% of aneurysmal evolution of the venous graft, or Loftus et al.,15 who reported 41% of aneurysmal evolution in venous grafts after PAA treatment at 2 years.
Apart from the fact that saphenous graft is not always available, using SFA eliminates congruence problems that usually arise with venous grafts. This technique allows performing end-to-end anastomoses because distal anastomosis can be performed on a healthy popliteal artery. And last, by using the SFA, the greater saphenous vein is preserved for possible distal or coronary bypasses.
Conclusion
Because of its caliber and its lack of deterioration, the SFA is a graft that can be used to treat isolated popliteal aneurysms. It has the required mechanical qualities to bear the strains of the knee flexure with satisfactory short- and long-term results. This technique represents an alternative to the use of an autologous saphenous vein or a prosthesis for aneurysms located at a level of flexure.
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Presented at the 22th Annual Meeting of the French Society for Vascular Surgery, Lyon, France, June 2-5, 2007.
PII: S0890-5096(09)00172-1
doi:10.1016/j.avsg.2008.05.020
© 2009 Annals of Vascular Surgery Inc. Published by Elsevier Inc All rights reserved.
