Original Article

Endoluminal graft stenting of peripheral aneurysms: questionable results compared with conventional surgery

M.C. Barry
T. Mackle 
L. Joyce 
C. Kelly 
F. McGrath 
D. Bouchier-Hayes 
A. Leahy
Departments of Surgery and Radiology, Royal College of Surgeons in Ireland and Beaumont Hospital, Dublin, Ireland

Correspondence to: Ms M.C. Barry, Department of Vascular Surgery, Room 926, 9th floor south, University Hospital Rotterdam, Dijkzigt Hospital, PO Box 2040, 3000 CA Rotterdam, the Netherlands

Introduction Methods Results

Discussion References

Keywords: Aneurysms, popliteal, fermoral, endoluminal grafts
Surg J R Coll Surg Edinb Irel., 1 February 2003, 42-44

Popliteal and femoral aneurysms can be treated by endoluminal graft stenting, instead of conventional surgery. Results in four cases suggest, however, that long-term results do not justify an endovascular approach

INTRODUCTION
Surgical exclusion and bypass using a prosthetic or autologous vein has long been the treatment of choice for symptomatic popliteal and femoral aneurysms.^1-4 More recently, endoluminal graft stenting has become a feasible alternative to conventional bypass surgery.^1,2 However, the long-term efficacy of endoluminal treatment remains to be evaluated.

This study reports four cases treated with endoluminal graft stenting and assesses the long-term effectiveness of these procedures.

METHODS
Four male patients (median age 71 years; range 52-75 years) underwent elective endoluminal graft stenting for femoral (n=2) and popliteal
(n=2) aneurysms. Two patients with popliteal aneurysms presented with symptoms due to microemboli. Both femoral aneurysms were asymptomatic and had been found incidentally on clinical examination. Three patients had signi.cant cardiovascular problems: two patients had suffered previous myocardial infarction; one patient had nephrotic syndrome with renal failure. The femoral and popliteal aneurysms were assessed preoperatively by duplex ultrasonography (Acuson Ltd.) followed by conventional angiography. Two patients were found to have concurrent small abdominal aortic aneurysms which did not require treatment.

A combined surgical and radiological approach was used in the operating theatre. Regional anaesthesia alone was used in two cases, but general anaesthesia was required in the other two cases. A transverse arteriotomy in the affected common femoral artery or below knee popliteal artery was done using an open surgical approach. Following anticoagulation with heparin, a guide wire was passed through the aneurysm. A nitinol covered graft stent (Cragg Endopro System 1, Mintec, Bahamas) was used in the four patients. A Minitec delivery system consisting of an introducer sheath and dilator was introduced over the guide wire and the graft stent pushed into its desired position under .uoroscopic control. A post-procedural angiogram was performed to check the position of the stents. Further stents were deployed if necessary in a proximal to distal interlocking manner. As the stents have a maximum length of 5cm, multiple stents were required to exclude the aneurysms completely.

RESULTS
Results are summarised in Table 1. Stenting was technically successful for both femoral aneurysms. Post-operative hospital stay ranged from 25 to 48 days. No patient required intra-operative or post-operative blood transfusion. One patient developed a large haematoma at the wound site 10 days postoperatively which resolved spontaneously. The femoral aneurysm recurred eight months later, but the patient refused further intervention and was lost to follow-up. The second patient had an uneventful postoperative recovery. Duplex scan at eight months showed a small leak from the distal end of the stent but this was asymptomatic. Both patients remained asymptomatic until they died from unrelated causes at seven months and two years, respectively.

Angiography following stent placement in the first patient to undergo popliteal aneurysm stenting revealed a moderately tight stenosis at the distal end of the stent which improved with angioplasty. Additional graft placement was required as a second procedure but failed to exclude the aneurysm entirely. This remains asymptomatic and follow-up with duplex ultrasonography confirms a patent graft. The second patient had a complicated post-operative course. Completion angiography revealed absent flow through the graft, but this was corrected with embolectomy. Graft thrombectomy was required one month later when the graft re-occluded. Four months later the patient re-presented with claudication. Angiography revealed complete occlusion of the popliteal artery above the stent with distal filling via collaterals. It was decided to manage this patient conservatively and at four-year follow-up his claudication distance has improved to 500 metres.

DISCUSSION
Popliteal and femoral aneurysms constitute over 90% of all peripheral aneurysms. Popliteal aneurysms are associated with a mean annual complication rate of 8.5%. Current treatment consists of bypass grafting with an autologous saphenous vein with proximal and distal ligation of the popliteal aneurysm. This approach is associated with 91% and 54% five-year patency rates in asymptomatic and symptomatic aneurysms, respectively.⁵ However, morbidity rates remain high in the management of this condition with major limb amputation rates of 36-69% in symptomatic and 4% in asymptomatic cases, managed surgically.

In contrast, femoral aneurysms are associated with much lower morbidity rates and surgical intervention is indicated with the development of acute expansion, major limb-threatening thrombo-embolic events or life-threatening symptoms. Current surgical technique consists of repair with dacron or PFTE graft using either an inlay technique or end-to-end anastomosis.⁴ Life expectancy rates in patients with popliteal and femoral aneurysms are signi.cantly poorer than the normal population, with a high incidence of comorbid medical conditions including hypertension, coronary artery disease and cerebrovascular disease.4 For many of these patients open surgical repair under general or regional anaesthesia poses a significant risk. All four patients in the current series had significant comorbid medical conditions.

Endoluminal grafting for femoral and popliteal aneurysms has become an alternative to open surgical treatment.^1-3 Stented graft repair is minimally invasive, eliminates the need for two incisions around the knee in the case of popliteal aneurysms and reduces transfusion requirements. A further advantage of the endoluminal stent approach to popliteal artery aneurysms is the preservation of the geniculate anastomosis. Most published reports have evaluated short-term outcome following peripheral arterial stenting procedures.^1,2

Placing of endoluminal stent grafts in the patients reported here was technically successful. However, dif. culties emerged in all four cases. Early recurrence of one popliteal aneurysm occurred in the first week and required placement of a further graft stent as a second procedure. Presumably this was due to shortening of the two stents which had already been deployed; the manufacturers suggest that 10% extra should be allowed for shortening of stents after deployment. The second patient treated for a popliteal aneurysm developed occlusion of the stent at one month. Despite thrombectomy the stent graft reoccluded and the patient continues to remain symptomatic at a follow-up of three years. One of the patients with a femoral aneurysm remained well and required no further treatment until his death at seven months. The fourth patient, who had a right femoral aneurysm treated successfully, developed a late recurrence, presumbly due to extension of disease. He refused treatment and remained well until his death at two years.

These results would suggest that caution must be exercised in recommending graft stenting for femoropopliteal aneurysmsas these early results are disappointing. All patients spent considerable lengths of time in hospital despite the less invasive surgical approach employed. The requirement for additional stents and secondary procedures negated to a large extent the purported benefits of endovascular stenting in terms of reduced operating time, morbidity and hospital stay. This has also been the experience of others who have reported excellent short-term results with significant thrombosis rates in the medium-term particularly, in stented popliteal artery aneurysms.⁶ Problems common to both femoral and popliteal artery aneurysm stent-grafting are the difficulty with access and the continuous .exion and extension which leads to kinking of the stent-graft and increases the risk of neointimal hyperplasia and occlusion.

In our experience, the stent-graft approach to femoral and popliteal artery aneurysms cannot be recommended given the medium to longterm dif.culties experienced. While technically feasible with acceptable results in the short-term, we suggest that the poor long-term results fail to support the use of stent-grafting as a treatment for infra-inguinal arterial aneurysms.

REFERENCES
1. Joyce, WP, McGrath, E, Leahy, AL, Bouchier-Hayes, D. A safe combined surgical/radiological approach to endoluminal graft stenting of a popliteal aneurysm. Eur J Vasc Endovasc Surg 1995; 10: 489-91
2. Marin, ML, Veith, RJ, Panetta, TE et al. Transfemoral endoluminal stented graft repair of a popliteal aneurysm. J Vasc Surg 1994; 19: 754-57 
3. Sapoval, MR, Long, AL, Raynaud, AC et al. Femoropopliteal stent placement. Longterm results. Radiology 1992; 184: 833-39
4. Hands, LJ, Collins, J. Infra-inguinal aneurysms; outcome for patient and limb. Br J Surg 1991; 78: 996-98 
5. Ouriel, K, Shortell, CK. Popliteal and femoral aneurysms. In: Rutherford, R.B. eds. Vascular Surgery. Philadelphia: W.B. Saunders, 1995; 1103-11 
6. Muller-Hylsbeck, S, Link, J, Schwarzenberg, H et al. Percutaneous endoluminal stent and stentgraft placement for the treatment of femoropopliteal qaneurysms: early experience. Cardiovasc Intervent Radiol 1999; 22: 96-102

Copyright: 6 March 2001

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