VESSEL UPDATE: INFRAPOPLITEAL


Clinical Application
of the Xpert Stent 


New data show effectiveness in the treatment of critical 
limb ischemia caused by infrapopliteal lesions. 

BY MARC BOSIERS, MD; KOEN DELOOSE, MD; JRGEN VERBIST, MD; AND PATRICK PEETERS, MD 

Peripheral arterial disease (PAD) remains a significant clinical problem in the US. More than 5 million Americans exhibit symptoms of PAD annually. Eighty percent (4 million patients) experience 
intermittent claudication, and nearly 1 million have critical limb ischemia.1-3 

Catheter-based interventional techniques, such as 
straightforward percutaneous transluminal angioplasty 
(PTA) or subintimal PTA, have shown promising results in 
different case series.4,5 Procedural success rates of standard 
balloon angioplasty vary from 80% to 100%6-10 and are 
higher for stenoses than for occlusionsin one series 84% 
versus 61%, respectively.11 The immediate technical success rate of subintimal PTA is somewhat lower, ranging 
from 78% to 85%.12,13 Patency rates as reported in the literature vary tremendously. One series reported a primary 
patency of 48% at 18 months, with a secondary patency 
of 56%,11 whereas other investigators report recurrent 
symptomatic stenosis at 1 and 3 years of 40% and 80%, 
respectively.7,14 Limb salvage rates are in the range of 70% 
to 86%.6,8,10,15 Results of subintimal PTA range similarly, 
with a reported primary and secondary patency of 56% at 
1 year.13 

One option is using balloon-expandable, coronary-type 
stents to treat small-diameter vessels. Stent implantation 
overcomes the most important drawbacks of PTA (eg, 
early plaque remodeling and vessel recoil), which tend to 
diminish the results of PTA fairly quickly and reduce the 
lumen diameter. Stents support the vessel wall to prevent 
early lumen loss, and the support continues until the vessel restores its original physiology. However, crushability 
and poor adaptablity are intrinsic disadvantages of balloon-expandable stents. Self-expanding stents have the 
potential to solve the limitations of balloon-expandable 
stents. First, crushability is not an issue. Furthermore, selfexpanding stents offer high kink resistance, high radial 
force, and homogenous wall coverage. 

This article evaluates the clinical outcome and stent 
performance of 42 consecutive cases in which the 4-F, 
self-expanding Xpert stent (Abbott Vascular Devices, 
Abbott Park, IL) was used. All cases were performed in 
the Department of Vascular Surgery of the AZ St-Blasius 
in Dendermonde, Belgium, and the Department of 
Cardiovascular and Thoracic Surgery of the Imelda 
Hospital in Bonheiden, Belgium. 

MATERIALS AND METHODS 

Vascular access was accomplished through a 4-F sheath 
introducer120 cm long for contralateral (crossover) 
approaches and 80 cm long for antegrade approaches. 
The long introducer sheath was positioned in the 
popliteal area to optimize device handling and imaging. 
The stenoses were traversed, and occlusions were 
recanalized with a conventional hydrophilic .035-inch or 
.018-inch guidewire. Stent deployment was accom-


Figure 1. Kapan-Meier graph of primary patency results. 

24 I ENDOVASCULAR TODAY I FEBRUARY 2006 


VESSEL UPDATE: INFRAPOPLITEAL


plished with a .018-inch wire to accommodate the lowprofile stent system. 

The lesion was dilated with a coronary-type balloon. 
In case of a suboptimal angiographic result after PTA 
(=50% residual stenosis) and/or flow-limiting dissection, 
it was decided to implant a self-expanding Xpert stent. 
An optimum angiographic result (<10% residual stenosis) was defined as immediate procedural success. 

Each patient was seen regularly after stent implantation. Physical examination was performed, and stent 
patency was evaluated by color flow duplex ultrasound. 
Daily aspirin therapy was initiated, and clopidogrel saturation (75 mg daily during at least 4 days or one loading 
dose of 300 mg the day before the procedure) was 
achieved prior to the procedure. Heparin was used during the procedure (bolus of 150 IU/kg body weight). The 
postprocedure antithrombotic regimen used accorded 
to the routine clinical practice of the hospital (75 mg 
clopidogrel daily for 1 month; 160 mg aspirin daily for 
life; fraxiparin 0.6 mL daily for 3 weeks). 

Data collection and analysis for preoperative, hospitalization, and follow-up information were performed by 
means of a Microsoft Access-based dataset. During the 
follow-up, the patency of the treated areas was assessed 
based on duplex peak velocity ratios and the incidence 
of reinterventions for the same bed. Patients not receiving any endovascular or surgical below-the-knee reintervention and not exhibiting significant restenosis on 
duplex (peak velocity ratio =2.0) were regarded as having primary patency. The clinical status of the patients 
was followed according to the Rutherford class changes 
and the absence of major amputations after index procedure (ie, limb salvage). Primary patency and limb salvage life tables were calculated using the Kaplan-Meier 
estimate method, for a period starting on the date of 
the procedure up to and including the most recent follow-up visit. 

RESULTS 

Between July 2003 and February 2005, 42 patients (27 
male) presenting with symptomatic critical limb 
ischemia (Rutherford categories 4 and 5) due to 
infrapopliteal arterial disease were treated by means of 
the 4-F, self-expanding Xpert stent. In total, 44 short 
below-the-knee lesions were stented. All patients had a 
diagnostic evaluation of suboptimal angiographic result 
after PTA (=50% residual stenosis) and/or flow-limiting 
dissection, before enrollment into the evaluation. 

The mean age of the treated patients was 74 years 
(range, 50-90 years). Risk factors were distributed 
according to what can be seen in similar patient populations. Hypertension was seen in 32 (76.2%) patients, dia-

Stented Vessel Number of SE Xpert Stents 
Total 5 mm 6 mm 
Popliteal artery (P3) 11 8 3 
Tibioperoneal trunk 25 25 
Anterior tibial artery 5 5 
Peroneal artery 1 1 
Posterior tibial artery 2 2 
*N=44 
TABLE 1. STENT DISTRIBUTION BY 
ANATOMIC LOCATION* 
betes in 16 (38.2%) patients, nicotine abuse in 18 
(42.9%) patients, and hypercholesterolemia in 21 (50%) 
patients. 

Contralateral access is the standard strategy for 
endovascular below-the-knee procedures. In this specific 
patient group, a contralateral approach was used in 36 
(85.7%) cases, whereas an ipsilateral approach was preferred in six (14.3%) cases. On average, it took 48 minutes 
(range, 20-90 minutes) to perform a procedure (skin-toskin). An average of 108 mL (range, 20-230 mL) contrast 
medium was used. On average, 13 minutes (range, 2-57 
minutes) of fluoroscopy time were needed. 

Preoperative lesion assessment showed an average 
stenosis percentage of 83% (range, 60%-100%) in arteries 
with a reference diameter of 3.6 mm (range, 3-5 mm). 
Calcification was seen in 27 (61.4%) occasions. 
Dissection, thrombus, and ulceration were observed in 
three (7%), three (7%), and one (2%) patient, respectively. 

An analysis of the 44 stenoses showed 25 (57%) lesions 
in the tibioperoneal trunk, 11 (25%) in the popliteal P3 
region, and five (11.4%), one (2%), and two (5%) in the 
anterior tibial, posterior tibial, and peroneal arteries, 
respectively (Table 1). 

Angiographic procedural success was achieved in all 
patients. According to the Kaplan-Meier method, primary patency was calculated to be 100%, 96.7%, and 
89.0% after 1, 3, and 6 months, respectively (Figure 1). 
Limb salvage rates of 100% were observed at each of 
these time points (Figure 2). 

DISCUSSION 

The data available on endovascular below-the-knee 
intervention are few, coming from only a few trials. To 
date, no data on stent use in this area have been published. A comparison can only be made with the data of 
Balmer et al4 who selected intraluminal PTA as the treatment of choice for these infrapopliteal lesions and other 
publications that focused on subintimal PTA.5,13 

Our results suggest that the use of stents results in a 

FEBRUARY 2006 I ENDOVASCULAR TODAY I 25 


VESSEL UPDATE: INFRAPOPLITEAL


higher immediate procedural success rate of the 
infrapopliteal endovascular intervention. We find a 100% 
immediate technical success rate after stenting. Several 
series on PTA alone report approximately a 90% immediate technical success for intraluminal PTA in treating 
stenosis, whereas it decreases to approximately 70% to 
80% for occlusions, underlining the necessity of stents to 
cope with the potential side effects of PTA, such as dissections, early plaque remodeling, and vessel recoil.6-10 

After 6 months, we can report an encouraging limb salvage rate of 100% and a primary patency rate of 89%. It 
remains to be seen whether this outcome will be sustained 
after a longer period of time. Balmer et al4 reported 90% 
prevention of amputation at 1 year after PTA of belowthe-knee arteries for patients with critical limb ischemia. 
Subintimal PTA for restoring blood flow in the below-theknee vessels seems to be able to prevent amputation in 
81% to 85% of cases.5,13 

CONCLUSION 

Our data suggest that the use of the self-expanding 
Xpert stent in infrapopliteal stenotic disease in patients 
with critical limb ischemia is safe and effective. The longterm results are promising, but more extensive series are 
mandatory to prove the superiority of stent use over PTA 
in below-the-knee vessels. 

ACKNOWLEDGMENTS 

The authors take great pleasure in thanking the staff of 
Flanders Medical Research Program (www.fmrp.be), with 
special regards to Koen De Meester and Erwin Vinck for 
performing the systematic review of the literature and providing substantial support to the writing of the article.  

Figure 2. Kapan-Meier graph of limb salvage results. 
Marc Bosiers, MD, is from the Department of Vascular 
Surgery, AZ St-Blasius, Dendermonde, Belgium. He has disclosed that he has no financial interest in any product or 
manufacturer mentioned herein. Dr. Bosiers may be 
reached at +32 52252735; marc.bosiers@telenet.be. 

Koen Deloose, MD, is from the Department of Vascular 
Surgery, AZ St-Blasius, Dendermonde, Belgium. He has disclosed that he has no financial interest in any product or 
manufacturer mentioned herein. Dr. Deloose may be 
reached at +32 52252517; koen.deloose@telenet.be. 

Jrgen Verbist, MD, is from the Department of 
Cardiovascular and Thoracic Surgery, Imelda Hospital, 
Bonheiden, Belgium. He has disclosed that he has no financial interest in any product or manufacturer mentioned 
herein. Dr. Verbist may be reached at +32 15506197; jurgen.verbist@imelda.be. 

Patrick Peeters, MD, is from the Department of 
Cardiovascular and Thoracic Surgery, Imelda Hospital, 
Bonheiden, Belgium. He has disclosed that he has no financial interest in any product or manufacturer mentioned 
herein. Dr. Peeters may be reached at +32 15506197; 
patrick.peeters@imelda.be. 

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