A new device for percutaneous mechanical thrombectomy in acute limb ischemia

Abstract

Acute limb ischemia caused by thromboembolism is an emergent and life-threatening disease. Rapid revascularization is inevitable to prevent major amputation. So far, thrombectomy by Fogarty balloon catheter has been a standard procedure for this emergent setting, though it is sometimes difficult to accomplish complete removal of thrombus within peripheral arteries. Herein, we report a case with acute limb ischemia which was successfully treated by a new mechanical thrombectomy device. This home-made device split thrombus into small pieces within arteries, and accelerated the efficiency of thrombus removal by an aspiration catheter thereafter.

Introduction

According to Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) [1], acute limb ischemia (ALI) is defined as any sudden decrease in limb perfusion causing a potential threat to limb viability. For saving limb and life, revascularization is required as soon as possible. The standard therapy is administration of unfractionated heparin intravenously (except in cases of heparin antibodies) [1], catheter-mediated thrombolysis, and surgery [2–4]. Surgical revascularization, however, has high amputation and postoperative mortality largely attributable to cardiopulmonary complications [5, 6]. On the other hand, catheter-based therapies such as percutaneous aspiration thrombectomy (PAT) or percutaneous mechanical thrombectomy (PMT) provide alternative non-surgical modalities for the treatment of ALI without the use of pharmacologic thrombolytic agents. Combination of these techniques with pharmacologic thrombolysis may substantially accelerate clot-lysis, which is important in severe ALI cases where time to revascularization is critical [1]. A new device “DISASTER: Diamond Shaped wire Accelerate Splicing process of Thrombus used for Emergent Revascularization” is a PMT device that fragments thrombus into small pieces and facilitates the thrombus aspiration. We describe the case of a 60-year-old man with ALI who was treated successfully by using “DISASTER”.

Case presentation

A 60-year-old man presented to our institution with a 2-days history of numbness and pain on his right leg. He has a medical history of hypertension for the last several years. On physical examination, he had a regular pulse rate of 70, and cold right extremity. Both femoral arterial pulses were palpable, but those of right popliteal artery (popA), posterior tibial artery (PTA) and dorsal pedis artery (DPA) were not detected. Ankle-brachial pressure index (ABI) was 0.52 in right leg. Left ABI was within normal range. Multi-detector computed tomography (MDCT) angiogram revealed that his right common iliac artery (CIA) and popA were totally occluded by thrombus. Right superficial femoral artery was partially visualized via collateral blood flow.

Angiography confirmed the total occlusion of the origin of right CIA (Fig. 1a). We decided to perform staged interventional procedure to right CIA and popA respectively. We tried to recanalize the right CIA first. “DISASTER” was inserted from right common femoral artery (CFA) retrogradely, and it fragmented thrombus finely (Fig. 1b) and a huge amount of thrombus was removed from the vessels by a thrombus aspiration device Thrombuster II (KANEKA, Japan). After this procedure was repeated several times, antegrade blood flow was recovered. Percutaneous transluminal angioplasty (PTA) balloon catheter, Aviator plus 7.0 × 40 mm (Cordis, Miami Lakes, Fla), was used to perform additional balloon angioplasty in the right CIA. SMART control stent 8.0 × 60 mm (Cordis, Miami Lakes, Fla) was deployed to treat a residual stenosis of the right CIA. Post-procedural angiography demonstrated almost complete dissolution of thrombus in the previously occluded CIA (Fig. 1c), though right popA was still occluded.

Fig. 1

a Angiography demonstrated acute thrombosis of the ostium of the right common iliac artery. b “DISASTER” was rotated within the right external iliac artery. Thrombus was scraped off from the vascular wall, and fragmented into small pieces at the same time. c Final angiography revealed complete removal of thrombus

Next day, we treated his right popA. Angiogram showed the total occlusion of right proximal popA (Fig. 2a). We used “DISASTER” again in his right popA. It was inserted from right CFA antegradely. The patient’s right calf was compressed by a manchette to the level of systolic blood pressure in order to prevent distal embolism (Fig. 2b). Again, “DISASTER” worked quite well, and a huge amount of thrombus was aspirated (Fig. 2c). After thrombus aspiration and balloon angioplasty, we confirmed that there was no remaining thrombus by means of contrast medium injection via aspiration catheter. Then, we released the pressure of manchette and performed angiogram. It revealed fully recovered blood flow from popA to toe (Fig. 2d). Minor thrombus existed in distal right anterior tibial artery (ATA), so we injected 60,000 IU of urokinase in cath-lab, and 180,000 IU of urokinase intravenously next 24 h.

Fig. 2

a Angiography showed that right popliteal artery was totally occluded. b “DISASTER” was used for the right popliteal artery. c Large amount of thrombus was aspirated. d Final angiography showed that blood flow in right ATA and PTA was restored, though small thrombus still remained within right ATA

The patient tolerated all these procedures well with no complications. Immediately after the second procedure, patient’s right foot became warm, and pulses in the PTA and DPA were restored. Right ABI returned to normal, 1.01. During the staged therapies, there was no sign of the worsening of ischemia. MDCT angiogram performed 2 weeks later demonstrated the patency of right ATA and PTA and complete dissolution of thrombus. He was discharged from our institution after adequate warfarization without any complications including myonephropathic-metabolic syndrome (Fig. 3) and motor paralysis.

Fig. 3

a–d Serum CPK, potassium, BUN, creatinine levels were not changed throughout the treatment

Discussion

ALI is an emergent disease, and a delay in the treatment is associated with a high risk of major amputation or death. It is necessary for limb salvage and saving life to diagnose as soon as possible and to recover the blood flow immediately. Surgical thrombectomy using Fogarty balloon catheter has been the standard method of treatment for ALI. However, Fogarty-mediated thrombectomy has been associated with the risk of vessel injury and distal embolism. Limb salvage rates of the procedure vary between 62 and 95% [7]. And in cases with poor medical condition, surgical treatment might be contraindication because of high mortality and morbidity.

Some studies have confirmed the important role of catheter-directed thrombolysis (CDT) in the treatment of ALI [2–4], though long-term indwelling of catheter increases complications [8]. Catheter-based therapies provide alternative non-surgical treatments for ALI without the use of pharmacologic thrombolytic agents. Many new devices for PMT have been shown to improve procedural and clinical outcomes [9–11]. However, catheter-based therapy was not able to remove thrombus completely, especially in the cases with huge thrombus burden.

“DISASTER” is a new device to split thrombus into small pieces within vessels and improve the efficiency of aspiration catheter. Minor thrombus remained after aspiration can be treated by CDT or systemic thrombolysis. “DISASTER” is composed of a 0.014 inch guide wire and a 4Fr angiographic catheter, and prepared in the catheterization laboratory prior to use. “DISASTER” is quite easy to prepare, thus it does not waste precious time in emergent ALI setting (Fig. 4a, b). In addition, this device accommodates various vessel diameters, and multiple lesions can be treated by only one device.

Fig. 4

a Overview of DISASTER system. b Tip of DISASTER system

In the presented case, thrombi in iliac artery and femoral artery were treated in two separate sessions, mainly because we judged the patient’s collateral flow to the infrainguinal circulation was fairly good. If the patient’s ALI condition was critical, it was possible to perform all procedures in a single session by means of contra-lateral crossover approach.

Although a 0.014 inch guidewire composing the DISASTER was widely used in conventional interventional procedures in coronary arteries and peripheral arteries, it may cause vascular injury during its usage. It is difficult, however, to discriminate arterial dissection created by the DISASTER system from the remaining mural thrombus on angiography. Thus, we have to carefully observe vascular injury and arterial run-off before completing the procedure. It should be appreciated that, so far, we have not experienced any acute closure after the usage of DISASTER system.

Conclusion

In conclusion, this report demonstrates that ALI can be treated safely and effectively by using a home-made device, “DISASTER”.

Appendix

How to make and use the “DISASTER” device.

DISASTER is a simple device composed of two components, a 0.014″ long guide wire (300 cm) and a 4Fr angiographic catheter (100 cm, straight or angle type). First, the guide wire is bent to 90° at the exact middle position (150 cm) (Fig. 5a). Two additional 135° bends are created at both sides of the first bend, 20 mm apart from the first bend. The direction of second bending must be opposite to the first one, so as to form a small mountain shape in the middle of the wire (Fig. 5b). Then, two ends of guide wire are inserted into the tip of the angiographic catheter, and advanced until both ends go out from the proximal hub of the catheter. The second bends of the guide wire should be aligned at the tip of the catheter. By these setting, the guide wire forms a diamond (or leaf like) shape. A torque control device is used proximally to hold the position of guide wire within the catheter (Fig. 5c).

Fig. 5

How to create the DISASTER system. a 0.014″ guide wire (300 cm) is bended to 90° at the middle position (150 cm). b Two additional 135° bends were created at both side of the first bend, 20 mm apart from the first bend. The direction of second bending is opposite to the first one, so as to form a small mountain shape at the middle of the wire. c The schema of DISASTER system. A torque control device was used proximally to hold the position of guide wire within the catheter

When using, DISASTER is inserted into the occluded segment via a catheter introducer sheath or guiding catheter, then rotated many times in the middle of thrombus. This maneuver scrapes out the thrombus from vessel wall, and split the thrombus into small pieces. If there is another guide wire within the vessel, DISASTER should not be rotated more than 720° in one direction to prevent entangling with another wire. In order to accommodate the device to smaller vessels, the diamond-sized shape can be reduced by pulling out the wire ends just a little and holding the position of wire ends by the torque control device again.