Outcome of Thrombolysis and Thrombectomy for Thrombosed Endografts Inserted in the Superficial Femoral Artery for Occlusive Disease

[Akute arterielle Embolie nach einer Knie-Totalendoprothese: Ein Bericht über zwei Fälle und Literaturübersicht]

Die akute arterielle Embolie ist eine seltene, aber schwerwiegende Komplikation nach einer Knie-Totalendoprothese (Knie-TEP). Es besteht ein allgemeiner Konsens darüber, dass in dieser Situation sofort eine Revaskularisation durchgeführt werden muss, aber die spezifische Behandlung ist immer noch umstritten. Wir berichten über zwei Fälle von Embolien der Kniekehlenarterie, die durch eine akute arterielle Thrombose nach Knie-TEP verursacht wurden. Bei beiden Patienten kam es nach der Operation zu einem Gefühls- und Bewegungsverlust der rechten unteren Extremität und einer Pulsationsschwächung der Arteria dorsalis pedis; eine Angiografie zeigte eine Embolie der Arteria poplitea. Einer der Patienten erhielt eine Thrombolysetherapie, entwickelte jedoch eine großflächige Infektion und Nekrose des rechten Wadenmuskels und benötigte nach erfolgreicher Thrombolyse ein mehrfaches Debridement und Hauttransplantationen. Bei dem anderen Patienten wurde eine Thrombektomie, eine Gefäßrekonstruktion und eine prophylaktische Fasziotomie durchgeführt; nach der Operation blieben ein Taubheitsgefühl im Fuß und eine leichte Streckschwäche zurück. Die Autoren empfehlen Chirurgen, Hochrisikopatienten mit Knie-TEP eine angemessene Aufmerksamkeit zu widmen. Vor der Operation sind eine sorgfältige Anamnese und körperliche Untersuchung erforderlich. Der chirurgische Eingriff sollte präzise und schonend durchgeführt werden, nach der Operation sind das Gefühl der Gliedmaßen und die Blutzirkulation aufmerksam zu beobachten. Bei abnormalem Fußgefühl und schwacher arterieller Pulsation sollten umgehend erforderliche Untersuchungen (Doppler-Ultraschall und Arteriografie) durchgeführt werden. Wenn eine arterielle Thrombose diagnostiziert wurde, muss die Blutversorgung sofort wiederhergestellt werden. Verzögert sich die Diagnose um mehr als 6 Stunden, kann eine prophylaktische Fasziotomie erforderlich sein, um nachteilige Folgen zu vermeiden.

Endovascular bypass as a strategy for long femoropopliteal lesions

INTRODUCTION

Endovascular treatment has become the predominant treatment modality for femoropopliteal lesions. In longer and more complex lesions advanced technology is often required to improve results, with the endovascular bypass being one of them.

EVIDENCE ACQUISITION

A systematic review of the literature was performed to determine the clinical and technical outcomes of the latest generation endoprosthesis, with heparin bioactive surface and contoured proximal edge.

EVIDENCE SYNTHESIS

13 articles were enrolled: 3 randomized controlled trials, 4 prospective multicenter trials and 6 retrospective studies. The VIASTAR trial showed that the endoprosthesis has a better two-year primary patency compared to bare metal stenting, especially in long lesions (62% vs. 27%, P=0.004). The SUPERB trial showed that the endoprosthesis had similar results compared to bypass surgery, albeit with less complications (31% vs. 55%, P=0.048). The RELINE study showed that treatment with an endoprosthesis had a better one-year primary patency compared to balloon angioplasty for in-stent restenosis (75% vs. 28%, P<0.001). In the cohort studies one-year patency rates ranged from 61% to 86% for primary patency, from 65% to 92% for primary assisted patency, and from 83% to 95% for secondary patency.

CONCLUSIONS

For long femoropopliteal lesions, the heparin-bonded endoprosthesis is related to better outcomes compared to bare nitinol stents, and comparable outcomes as with the femoropopliteal bypass, but with less complications. There is a wide range in primary patency rates, with consistent high secondary patency rates. The endovascular bypass can be considered an appropriate strategy in these patients.

Trans-stent graft thrombectomy for the treatment of long stent graft thrombosis in the femoropopliteal artery

At present, no consensus has been reached regarding the optimal management of stent graft thrombosis in the femoropopliteal artery. We present a case of long thrombosis of a Viabahn stent graft implanted in the superficial femoral artery that was successfully treated by thrombectomy using a trans-Viabahn approach at the mid-thigh segment. The advantages of this approach include that it preserves the common femoral artery and popliteal artery untouched without scarring, allowing for a future site of surgical anastomosis. This technique could be a reasonable approach when performing surgical thrombectomy for stent graft thrombosis in the femoropopliteal artery.

Inhibition of edge stenosis of endografts in swine iliac arteries by a novel endograft with biodegradable coating at both ends

Objective

This study evaluated the effectiveness and safety of a novel endograft with a biodegradable coating at both ends in preventing edge stenosis in swine iliac arteries. The biodegradable coating was composed of polylactide and paclitaxel.

Methods

Four types of endograft were implanted in the iliac arteries of healthy swine: an endograft without coating (control group) and endografts with polylactide and paclitaxel coating containing 0.1, 0.3, or 3.6 μg/mm² of paclitaxel. The edge stenosis of these endografts in swine iliac arteries was assessed using angiographic image data at 30, 90, and 180 days after the operation. After terminal angiography, histologic evaluation of the treated arteries was performed. The treated sections of iliac arteries and blood samples were obtained at 1, 7, 30, 90, and 180 days for pharmacokinetic analysis.

Results

The results of angiographic and histologic evaluation demonstrated that intimal hyperplasia contributed to edge stenosis and polylactide-paclitaxel coating effectively inhibited edge stenosis. At 30 days, edge stenosis was observed at both the proximal and distal edges of the endograft without coating. At 90 days, edge stenosis was detected for the endograft coated with 0.1 μg/mm² paclitaxel, and ectasia dilation occurred at the proximal and distal edges of the endograft coated with 3.6 μg/mm² paclitaxel. No edge stenosis or other adverse effects were observed at 90 and 180 days for the endograft coated with 0.3 μg/mm² paclitaxel. In addition, for the endograft coated with 0.3 μg/mm² paclitaxel, a pharmacokinetic analysis showed that the paclitaxel concentration of treated segments decreased from 14 264 ± 1020 ng/g at day 1 to 80 ± 70 ng/g at day 90, and 20 ± 40 ng/g at day 180. The plasma paclitaxel concentration was low at day 1 and no longer detected after 7 days.

Conclusions

Polylactide and paclitaxel coating containing 0.3 μg/mm² paclitaxel at both ends of endografts effectively and safely inhibits edge stenosis in swine iliac arteries.

Clinical Impact of Stent Graft Thrombosis in Femoropopliteal Arterial Lesions

OBJECTIVES

This study sought to elucidate the clinical impact and prognosis of stent graft (SG) thrombosis.

BACKGROUND

The VIABAHN SG offers a favorable outcome in long peripheral artery occlusive disease (PAOD) lesions in the femoropopliteal artery. One concern after SG deployment is the incidence of stent thrombosis and consequent acute limb ischemia (ALI).

METHODS

In this retrospective multicenter study, we collected the clinical data of PAOD patients treated with VIABAHN SG who subsequently experienced SG thrombosis. The clinical symptoms of SG thrombosis, patency after reintervention, and predictors of loss of patency after reintervention were examined.

RESULTS

VIABAHN SGs were used for 1,215 patients; SG thrombosis occurred in 159 (13%) patients at a median of 6.4 months (interquartile range: 2.8 to 13.5 months) after SG implantation; 21 (13%) patients presented with ALI. A total of 131 (82%) patients underwent reintervention for SG thrombosis, whereas 2 (1%) underwent primary major amputation and the remaining 26 (16%) were treated conservatively. The patency rate 1 year after reintervention, freedom from major adverse limb events, and limb salvage after reintervention were 54.9%, 73.6%, and 92.5%, respectively. Critical limb-threatening ischemia at SG implantation and ALI presentation at SG thrombosis were positively associated with an increased risk of rethrombosis, whereas distal stent diameter was negatively associated with the risk of rethrombosis.

CONCLUSIONS

SG thrombosis is associated with a considerable risk of ALI, but the risk of primary major amputation was not high. Clinical outcomes after reinterventions for thrombosed SGs were suboptimal.

Heparin-Bonded Stent-Graft for the Treatment of TASC II C and D Femoropopliteal Lesions: 36-Month Results of the Viabahn 25 cm Trial

PURPOSE

To evaluate the 36-month technical and clinical outcome after implantation of the 25-cm Viabahn endoprosthesis with Propaten bioactive surface in TransAtlantic Inter-Society Consensus II C and D lesions of the superficial femoral and proximal popliteal arteries.

MATERIALS AND METHODS

This prospective, multicenter, single-arm trial (ClinicalTrials.gov; identifier NCT01263665) enrolled 71 patients (mean age 66.7±8.3 years; 50 men) with lifestyle-limiting claudication or rest pain (Rutherford category 2-4) and long (>20-cm) lesions of the superficial femoral and proximal popliteal arteries. Primary endpoint was primary patency at 36 months. Secondary endpoints included primary assisted patency; secondary patency; freedom from target lesion revascularization (TLR); freedom from a composite of death, target vessel revascularization (TVR), and amputation; clinical success; and freedom from device fracture.

RESULTS

Primary patency estimated by Kaplan-Meier analysis was 40.6% at 36 months. Primary assisted patency and secondary patency estimates were 53.0% and 96.9%, respectively. Within 36 months, 27 patients had to undergo a TLR. Twenty-five patients (35.2%) had a TVR. Freedom from the composite of death, TVR, and amputation endpoint was 44.5%. The estimate of the sustained clinical success with stable or improved Rutherford category was 58.5%. No stent fracture was detected during follow-up.

CONCLUSION

The primary patency rate without reintervention after treatment of long femoropopliteal lesions is low. However, secondary patency after implantation of a Viabahn endoprosthesis is high and seems to be superior to the use of other revascularization techniques, resulting in persistent clinical improvement.

Drug-coated balloon angioplasty for the treatment of edge stenosis after self-expanding covered stent placement for superficial femoral artery occlusive disease

BACKGROUND

Edge stenoses are the predominant limitation of self-expanding covered stent treatment of superficial femoral artery (SFA) occlusive disease, necessitating reinterventions. Angioplasty of an edge stenosis is associated with a high recurrence rate. Drug-coated balloon (DCB) treatment of edge stenoses might improve outcomes by decreasing the incidence of restenosis.

PURPOSE

The aim of this study was to evaluate the outcomes of using a DCB for the treatment of edge stenoses after self-expanding covered stent placement for SFA occlusive disease.

METHOD

We performed a retrospective analysis of patients treated with a DCB for edge stenoses after self-expanding covered stent placement. The primary endpoint was primary patency at one year. The secondary endpoints included procedure-related complications, secondary patency, and freedom from target lesion revascularization (TLR).

RESULTS

A total of 21 patients with 28 edge stenoses were included. The time from primary treatment to treatment of the edge stenosis was 19 months (interquartile range (IQR) 8; 52 months). Primary patency and assisted primary patency at one year were 66.7% with a secondary patency of 90.9%. Freedom from TLR was 86.1%, and freedom from clinically driven TLR was 89.4%. Four patients presented with a hemodynamically significant restenosis, and three of those patients had an occlusion. Median time to failure was six months (IQR 3.5; 7.0 months), and median time to occlusion was four months (IQR 3.0; 6.0 months).

CONCLUSION

The treatment of edge stenoses using a DCB is associated with a safe one-year outcome; however, this has to be confirmed in larger prospective studies. The continuous surveillance of patients is indicated.

Edge Stenosis After Covered Stenting for Long Superficial Femoral Artery Occlusive Disease: Risk Factor Analysis and Prevention With Drug-Coated Balloon Angioplasty

Purpose: To report a retrospective analysis of risk factors for edge restenosis after Viabahn stent-graft treatment of superficial femoral artery (SFA) occlusive disease and determine any protective effect of drug-coated balloons (DCBs) used at the time of stent-graft implantation. Methods: Between October 2011 and July 2016, 110 patients (mean age 73.3±7.6 years; 78 men) were treated with the Viabahn stent-graft for long SFA occlusions. Thirty-eight (34.5%) patients had DCB reinforcement at the distal edge of the stent-graft. For analysis, the population was divided into groups of no edge stenosis patients (n=88; mean lesion length 22.4±4.2 cm) and edge stenosis patients (n=22; mean lesion length 23.5±5.7 cm). The clinical outcomes, ankle-brachial indices, computed tomography angiography findings, and patency were compared at a minimum of 12 months. Logistic regression analysis was employed to determine risk factors for edge stenosis; the results are presented as the odds ratio (OR) and 95% confidence interval. Results: No differences in clinical or procedural characteristics were identified except the higher incidence of diabetes (p=0.008) and greater need for retrograde access (p=0.033) in the edge stenosis group. DCB reinforcement reduced the incidence of edge stenosis (p=0.021) and target lesion revascularization (TLR; p=0.010) and resulted in a significantly higher 1-year primary patency rate (92.1% vs 76.4%, p=0.042). However, multivariate analysis revealed only poor distal runoff (OR 0.31, 95% CI 0.11 to 0.83, p=0.020) as a predictor of edge stenosis. Conclusion: The risk of edge stenosis after Viabahn implantation was higher in patients with poor distal runoff. DCB reinforcement over the distal edge reduced edge stenosis, decreased 1-year TLR, and improved 1-year primary patency.

Peripheral Stent Thrombosis Leading to Acute Limb Ischemia and Major Amputation: Incidence and Risk Factors in the Aortoiliac and Femoropopliteal Arteries

PURPOSE

To report the real-world incidence and risk factors of stent thrombosis in the aortoiliac and femoropopliteal arteries in case of bare nitinol stent (BNS) or covered nitinol stent (CNS) placement from a single-centre retrospective audit.

MATERIALS AND METHODS

Medical records of consecutive patients treated with peripheral stent placement for claudication or critical limb ischemia were audited for definite stent thrombosis defined as imaging confirmed stent thrombosis that presented as acute limb-threatening ischemia. Cases were stratified between aortoiliac and femoropopliteal anatomy. Cox regression analysis was employed to adjust for baseline clinical and procedural confounders and identify predictors of stent thrombosis and major limb loss.

RESULTS

256 patients (n = 277 limbs) were analysed over a 5-year period (2009-2014) including 117 aortoiliac stents (34 CNS; 12.8 ± 5.0 cm and 83 BNS; 7.8 ± 4.0 cm) and 160 femoropopliteal ones (60 CNS; 21.1 ± 11.0 cm and 100 BNS; 17.5 ± 11.9 cm). Median follow-up was 1 year. Overall stent thrombosis rate was 6.1% (17/277) after a median of 43 days (range 2-192 days) and affected almost exclusively the femoropopliteal segment (12/60 in the CNS cohort vs. 4/100 in the BNS; p = 0.001). Annualized stent thrombosis rates (per 100 person-years) were 12.5% in case of CNS and 1.4% in case of BNS (HR 6.3, 95% CI 2.4-17.9; p = 0.0002). Corresponding major amputations rates were 8.7 and 2.5%, respectively (HR 4.5, 95% CI 2.7-27.9; p = 0.0006). On multivariable analysis, critical leg ischemia and CNS placement were the only predictors of stent thrombosis. Diabetes, critical leg ischemia, femoropopliteal anatomy, long stents and CNS were independent predictors of major amputations.

CONCLUSIONS

Placement of long femoropopliteal covered nitinol stents is associated with an increased incidence of acute stent thrombosis and ensuing major amputation. Risks are significantly lower in the aortoiliac vessels and with use of bare nitinol stents.

Five-Year Outcome of Self-Expanding Covered Stents for Superficial Femoral Artery Occlusive Disease and an Analysis of Factors Predicting Failure

Purpose: To investigate the 5-year outcome of patients treated with self-expanding covered stents for superficial femoral artery (SFA) occlusive disease and identify parameters that could predict loss of primary patency. Methods: In a dual-center study, 315 consecutive patients (mean age 69.0±10.1 years; 232 men) treated for SFA occlusive disease in 334 limbs with Viabahn self-expanding covered stents between 2001 and 2014 were retrospectively analyzed. Mean lesion length was 11.7±8.8 cm, and half of the lesions were classified as TASC II C/D. Five-year patency rates were calculated, and Cox regression analyses were performed to assess potential factors affecting patency. Results: All-cause mortality at 5 years was 14.1%. Primary patency rates at 1, 3, and 5 years were 72.2%, 51.8%, and 47.6%, respectively, with secondary patency rates of 86.2%, 78.7%, and 77.5%. Parameters predicting loss of primary patency in a univariate analysis were covered stent diameter (p=0.001), the number of covered stents per lesion (p=0.015), and TASC II D classification (p=0.007). Covered stent diameter was the only parameter predicting loss of primary patency in the multivariate regression analysis (p=0.001), with 7-mm covered stents having superior performance. Conclusion: Five-year patency rates of self-expanding covered stents inserted for SFA occlusive disease are within an acceptable range. Covered stent diameter is the most relevant factor in predicting loss of primary patency, and thus, an adequate diameter of the distal landing site seems to be among the most important factors in the decision-making process. In smaller vessels, one should not use covered stents but venous conduits, as oversizing may be detrimental.