Mechanical atherothrombectomy in the treatment of peripheral arterial in-stent occlusions

Abstract

Background

Endovascular mechanical atherothrombectomy (MATH) is the technique that removes occlusive masses from vessel lumen. In patients with in-stent arterial occlusions, this modality can exclude or reduce the wall barotrauma associated with balloon angioplasty, necessity of additional stent implantation and the risk of open surgery. However, adoption of MATH has been slow mainly due to limited experience with the technique.

Method/results

The purpose of this minireview is to present a pictorial anatomic series of managed lesions and immediate therapeutic results documented angiographically. This may help the reader to select efficient technique for safe and successful treatment even in difficult anatomic conditions.

Conclusion

Endovascular mechanical atherectomy with the Rotarex catheter can be helpful in recanalization of lower limbs arterial in-stent occlusions. It can be used also when other therapeutic modalities are risky or inefficient.

Keywords

Mechanical thrombectomy limb ischemia arterial occlusion angioplasty stenting

Introduction

Bare metal, drug-eluting and covered stents are important tools for the endovascular treatment of lower limb arterial disease to ensure vascular patency. In patients with lower limb ischemia, they are beneficial to assure a patent lumen following arterial elastic recoil and/or flow-limiting dissection. The majority of stents implanted are nitinol, self-expandable stents with closed-cell, open-cell or interwoven designs. Long-term patency of stented arterial segments is influenced by multiple factors (ischemic symptoms, lesion location and length, runoff, vessel diameter, stent fractures and length). Therefore, the primary patency rates at 12 months have been reported in a wide range of 46–89%^1,2 in the femoropopliteal segment. Also, the frequency rate of the stent fractures was identified in range of 3%³ to 36%⁴ of treated limbs at 12 months. Higher primary patency rates at 12 months were reported for iliac stents (96%).^5,6 A recently published study that focused on the Rotarex treatment of in-stent iliac and infrainguinal arterial occlusions⁷ reported the procedure success in 98.6% of patients with restenosis rate 20.5% at 12 months. The occlusion or stenosis of a stented artery usually causes the recurrence of ischemic symptoms, that can be even more serious than before stenting.

Compared to surgery, mechanical atherothrombectomy (MATH) is a less invasive procedure with avoidance of general anesthesia and with the opportunity to immediately treat the underlying cause and concomitant lesions. Furthermore, this technique does not require intensive care unit stay.

Poor prognosis with reocclusion rate of 64.6% (reocclusion + restenosis rate: 84.8%) at 24 months was reported for in-stent occlusions managed by balloon angioplasty (PTA) alone.⁸ Without removal of occlusive material (debulking), PTA or stenting are associated with augmented arterial wall strain and the deep wall trauma that can elevate the restenosis rate. Furthermore, PTA and stenting are usually not applicable to fresh thrombosis where the risk of peripheral embolization is enormous.

The Rotarex device: Mode of action

The Rotarex (Straub Medical AG, Wangs, Switzerland) is a single lumen catheter incorporating a stainless steel helix rotating at up to 60,000 r/min. The Rotarex catheters are equipped with a rotating head driven by the helix, and comprise two superimposed stainless steel cylinders, each with two lateral openings; the outer cylinder is connected to the rotating helix, and the inner cylinder to the catheter shaft. The shape of the head facilitates the detachment and fragmentation of the occlusive material together with a strong vortex created by rotation. The displaced occlusion fragments are aspirated through head openings, and, during that passage, are shredded again into debris that is transported to an external collecting bag. Adjunctive techniques (balloon angioplasty, stenting, percutaneous aspiration thromboembolectomy) can be used to treat underlying (residual) lesions after debulking.

Lumen diameter ≥3 mm and intraluminal passage of the guidewire are the conditions necessary for the Rotarex usage.

Why MATH?

The Rotarex®S catheter has the potential for rapid removal (in a few minutes) of fragmentable atheroma, thrombus and myointimal hyperplasia even in long occlusive lesions.⁹ As a result, the number of re-PTA and re-stenting procedures can be reduced. In acute and subacute in-stent occlusions, the risk of serious bleeding is reduced when mechanical removal of fresh occlusive material eliminates the need for thrombolysis.⁹ Additionally, after successful Rotarex treatment, residual stenoses are shorter, less significant than original occlusions⁹ and require shorter stents, if any. Removal of occlusive masses with uncovering the endothelial layer can enable or facilitate drug uptake to the arterial wall from drug coated balloons.

Methodical notes

Rarely, problems with direct contact between the Rotarex rotating head and stent struts occur during mechanical debulking. Nevertheless, because such a contact can damage the catheter some caution and preventative measures are necessary. The operator has to exercise caution at the moment when the rotating head is introduced into the proximal end of the stent and an increase in sound frequency is noted. A very slow catheter advancement can be recommended at this moment or alternatively introducing the catheter about 1 cm within the stent without device activation. On withdrawing the catheter to the original position, the Rotarex can be activated again and its introduction repeated.

Where a significant proximal stenosis is present that does not allow sufficient blood flow to the rotating head, collapse of the arterial and stent walls may occur (Figure 1(a) and (b)). Subsequently, catheter damage can occur when the stent structure is irregular, deformed or interrupted. Careful visual monitoring of the stent anatomy is important before and during catheter introduction and if necessary, a proximal lesion should be treated e.g. with PTA before debulking continues.

Figure 1.

(a) Non-active Rotarex S catheter located inside the stent. Diameter of the stent (arrow) is appropriate. (b) The Rotarex activation can lead to stent (vessel) wall collapse (arrow) when blood flow to the rotating head is low or absent. Thus, the struts can get into the close contact with rotating head and its windows. A significant proximal lesion is usually the cause and vessel collapse disappears after catheter is deactivated or the proximal lesion successfully managed. (c) Careful examination of the occluded stent before treatment can reveal strut fractures (arrows), deformations or sequestrated stent fragments (double arrow). (d) The Rotarex catheter penetrating a multi-fractured, deformed and fragile stent can excise one of the struts, which lodges within the helix and can jam the mechanism. Care must be taken when approaching strut fractures, deactivating the catheter, passing the fractured segment and reactivating of the catheter.

Before mechanical debulking of an occluded, stented artery it is necessary to carefully inspect the stent structure to assess its geometry, continuity, deformation, fractures, strut protrusion into the lumen and sequestration of metallic fragments (Figure 1(c) and (d); Figure 5(b)).

In-stent occlusions of the proximal common iliac artery should not be managed from a contralateral approach. Due to elasticity of the Rotarex catheter and its internal strain when bent over the aortic bifurcation, the rotating head may get in close contact with the outer (lateral) wall of the stent and safe catheter advancement can be impossible.

In-stent occlusions of the common iliac arteries are usually managed from ipsilateral retrograde puncture of the common femoral artery (Figures 2 and 3). In this case, additional saline injection through the side-port of the introducer sheath is necessary to prevent vessel collapse distal to the occlusion during the Rotarex run-time. At the same time, the contralateral common iliac artery should be occluded by the balloon catheter to prevent embolism to the healthy limb.

Figure 2.

A 56-year-old woman with acute right lower limb ischemia, category IIb. (a) In-stent occlusion of the right common iliac artery (arrow). (b) Angiography after Rotarex catheter debulking and (c) balloon angioplasty.

Figure 3.

A 77-year-old man with bilateral chronic limb ischemia, Rutherford category 4. (a) Occlusion of aortic bifurcation (arrow) and common iliac arteries. The external iliac arteries are filled via collaterals (double arrows). (b) Margins of the stents are depicted by arrows. (c) Angiography after bilateral mechanical debulking with the Rotarex catheter and balloon angioplasty.

Crossover introducer sheath enables safe debulking of the contralateral iliac external artery.

Ipsilateral, antegrade puncture is preferable whenever possible for infrainguinal in-stent stenoses and occlusions (Figures 4 to 8). Infrapopliteal arteries can be managed when their diameter is 3 mm or more (Figure 9).

Figure 4.

A 59-year-old man with acute ischemia of the right lower limb, category IIb. (a) The superficial femoral artery is occluded at its origin (white arrow), proximal margin of stented area is depicted by black arrow. (b) The popliteal artery (arrow) is filled via collaterals. (c) Angiography after mechanical debulking with the Rotarex catheter and (d) following adjunctive balloon angioplasty. Distal margin of stented area is depicted by arrow.

Figure 5.

A 62-year-old woman with subacute ischemia of the right lower limb, Rutherford category 4. (a) In-stent occlusion of the popliteal artery with strut fractures depicted by arrows. (b) Interwoven stent design can be clearly seen with high-grade fractures – arrows. (c) Angiography after debulking alone. (d) Final result after low- pressure balloon angioplasty.

Figure 6.

A 63-year-old woman with chronic ischemia, Rutherford category 3. (a) In-stent occlusion of the popliteal artery (marked with arrows). (b) Stent distal margin (arrow). (c) Angiography after debulking and (d) after adjunctive balloon angioplasty.

Figure 7.

A 67-year-old man with subacute ischemia of the left lower limb, Rutherford category 3. (a) Occluded left superficial femoral artery with stents marked by double arrow. (b) Popliteal artery is filled via collaterals. (c) Angiography after debulking with the Rotarex catheter. (d) Residual stenosis (arrow). (e) Final result after adjunctive stenting.

Figure 8.

A 71-year-old man with chronic ischemia, Rutherford category 3. (a) Diffuse in-stent stenosis of left femoropopliteal arterial segment. (b) Distal end of stented area is depicted by arrow. (c and d) Angiography after mechanical debulking with the Rotarex S catheter and gentle balloon angioplasty.

Figure 9.

A 66-year-old man with chronic ischemia of left lower limb, Rutherford category 4. (a) In-stent occlusion of the tibioperoneal trunk (delineated by arrows). (b) Angiography after mechanical debulking with the Rotarex catheter alone.

Conclusions

Mechanical debulking with the Rotarex catheter can be safely used as an initial treatment of in-stent acute, subacute and chronic occlusions in patients with lower limb ischemia. The modality can be successful and reduce the need for stenting even in difficult anatomic conditions. Typical cases with angiograms documenting the technical effects are presented.

Footnotes

Declaration of conflicting interests

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: MB was proctoring for Straub Medical AG.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Miroslav Bulvas

References

Yong

Min

Yonggang

, et al. Comparison of drug-eluting stent with bare-metal stent implantation in femoropopliteal artery disease: a systematic review and meta-analysis. Ann Vasc Surg 2018; 50: 96–105.

Peker

Balendran

Paraskevopoulos

, et al. Demystifying the use of self expandable interwoven nitinol stents in femoropopliteal peripheral arterial disease. Ann Vasc Surg 2019; 59:285–292.

Laird

Katzen

Scheinert

, et al. RESILIENT Investigators. Nitinol stent implantation versus balloon angioplasty for lesions in the superficial femoral artery and proximal popliteal artery: twelve-month results from the RESILIENT randomized trial. Circ Cardiovasc Interv 2010; 3: 267–276.

Scheinert

Sax

, et al. Prevalence and clinical impact of stent fractures after femoropopliteal stenting. J Am Coll Cardiol 2005; 45: 312–315.

Hamer

Borisch

Finkenzeller

, et al. Iliac artery stent placement: clinical experience and short-term follow-up regarding a self-expanding nitinol stent. J Vasc Interv Radiol 2004; 5: 1231–1238.

Reyes

Carreira

Gude

, et al. Long-term follow-up of iliac wallstents. Cardiovasc Intervent Radiol 2004; 27: 624–631.

Milnerowicz

Kuliczkowski

, et al. Rotational atherectomy plus drug-coated balloon angioplasty for the treatment of total in-stent occlusions in iliac and infrainguinal arteries. J Endovasc Ther 2019; 26: 316–321.

Tosaka

Soga

Iida

, et al. Classification and clinical impact of restenosis after femoropopliteal stenting. J Am Coll Cardiol 2012; 59: 16–23.

Bulvas

Sommerová

Vaněk

, et al. Prospective single-arm trial of endovascular mechanical debulking as initial therapy in patients with acute and subacute lower limb ischemia: one-year outcomes. J Endovasc Ther 2019; 26: 291–301.