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follows that ulcer prevention or treatment is the best way to

prevent amputation.

If an ulcer is present, the primary objective is to achieve

fast ulcer healing. If there is concomitant infection ulcer

healing is often more difﬁcult to achieve. Optimal wound

care, antibiotics, off loading and other techniques are all

applied in daily practice to achieve ulcer healing, but active

revascularisation also plays a crucial role. Non-surgical

options for revascularisation of the DF have expanded over

the last decade and have become a prominent tool to pre-

vent amputation (Faglia et al. 2002). From a recent sys-

tematic review it is obvious that surgery and endovascular

treatment for below the knee (BTK) vessels have broadly

similar results.

2 Epidemiology and Aetiology

The term critical limb ischaemia refers to a condition

characterised by chronic ischaemic rest pain, ulcers or

gangrene in one or both legs attributable to objectively

proven arterial occlusive disease. Critical limb ischaemia

implies chronicity and is to be distinguished from acute

limb ischaemia. Its incidence is approximately 500–1000

per million per year, with the highest rates among older

people, smokers and diabetics. Furthermore, patients with

critical limb ischaemia have an elevated risk of future

myocardial infarction, stroke and vascular death, threefold

higher than patients with intermittent claudication. Critical

ischaemia should therefore not be seen and treated as a

stand-alone manifestation of peripheral arterial disease

(PAD) and management of associated risk factors is very

important to favourably inﬂuence the risk proﬁle in each

patient suffering from PAD.

The main pathological causes of critical lower limb

ischaemia are atherosclerosis, diabetic vascular disease,

embolic disease and thrombangitis obliterans (Buerger’s

disease).

It has become apparent that there is a clear difference

between critical lower limb ischaemia due to atherosclerosis

compared to that due to diabetes. The BTK lesions in ath-

erosclerosis are almost always accompanied by lesions in

the more proximal vessels, while this is rare in diabetic

arterial disease.

Diabetic arterial disease often shows long segmental

occlusions (Fig. 1) while atherosclerosis often shows short

focal lesions. The calciﬁcations in diabetic disease are

typically a manifestation of medial sclerosis (Fig. 2) while

in atherosclerosis the calciﬁcations are diffuse and intimal.

Also, there is often less disease in the pedal arteries in

diabetes, while in atherosclerosis the disease is often more

pronounced in those vessels with consequently fewer

endovascular options due to very poor outﬂow.

Fig. 1 a View of the leg below the level of the knee joint. The

posterior tibial artery is severely diseased from its origin and occludes

soon afterwards. The occlusion is long, which is typical of diabetic

vascular disease. b This view of the proximal calf shows extensive

occlusive disease affecting the tibioperoneal trunk and the posterior

tibial artery. The anterior tibial artery shows a long stenosis. All of

these features are commonly observed in diabetic vascular disease

Fig. 2 This view of the distal

posterior tibial artery, with

guidewire in situ prior to

angioplasty, shows the typical

distribution of calciﬁcation seen

in diabetic vascular disease

82 J. Reekers

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Diabetic foot lesions are often pain free due to the

concomitant neuropathy while rest pain and painful ulcers

are almost always seen in atherosclerotic disease. The

combination of rest pain and an ulcer can be seen in DF but

this is less common.

Only 5% of all patients with intermittent claudication

ﬁnally develop critical limb ischaemia. In that patient group

the clinical course of atherosclerotic disease is often pro-

gressive from claudication to rest pain (sometimes with an

ulcer) with the presence of severe atherosclerotic stigmata.

In the DF there is frequently no history of claudication and

there are no atherosclerotic stigmata more proximally.

An arterial ulcer on the DF is frequently not caused by an

acute or semi-acute arterial occlusion but by a distortion of

the, often chronic, equilibrium between poor blood inﬂow

due to vessel disease and low demand. Some now make a

clear differentiation by using the phrase critical ischaemia

for atherosclerosis and not for arterial diabetic disease,

which is then referred to as DF.

In patients with atherosclerotic disease, rest pain and

sometimes an ulcer, a more durable solution has to be

achieved. Early re-occlusion will immediately bring back

the rest pain despite a successful ulcer healing. In these

patients there is certainly room for technical improvement

to increase long-term patency.

3 Treatment Options

Surgical options including amputation and bypass surgery

have dominated treatment for decades. Despite this, the ﬁrst

percutaneous transluminal angioplasty (PTA) ever per-

formed, by Dotter in 1964, was for critical ischaemia.

Patency rates after infrapopliteal bypass surgery are inﬂu-

enced by many factors including inﬂow state, type of con-

duit, number of calf vessels, presence of uninterrupted ﬂow

to the foot and patency of pedal vessels (Aune et al. 1996;

Bertele et al. 1999; Panayiotopoulos et al. 1997). Published

success rates are highly variable; this is probably accounted

for by patient selection (Roder et al. 1997; Panneton et al.

2000; Cavillon et al. 1998).

Primary patency rates after distal venous bypass can be

up to 58% at 1 year and 37% at 5 years. For prosthetic

grafts, patency rates are much lower (Horvarth et al. 1990)

and the use of prosthetic graft material has been more or

less abandoned for distal bypass surgery. Balloon angio-

plasty was for some time considered a second best treat-

ment. However, with the publication of excellent results for

angioplasty, including the use of subintimal techniques, in

the early 1990s, this changed (Horvarth et al. 1990;

Flueckiger et al. 1992; Hauser et al. 1996; Schwarten and

Cutcliff 1988). Percutaneous treatment is now seen by many

as the ﬁrst option for treatment of critical ischaemia due to

crural vessel disease.

3.1 Indications for Treatment

The primary indication for crural intervention is limb sal-

vage. However with the known low complications rate from

PTA, Fontaine IIb is also seen by some authors as an

indication to treat stenosis (Horvarth et al. 1990; Flueckiger

et al. 1992; Hauser et al. 1996; Schwarten and Cutcliff

1988). For occlusions, however, claudication is not con-

sidered an appropriate indication, as there is a high potential

complication rate, such as the potential for limb loss.

In the literature, the rate ofprimary amputation for critical

lower limb ischaemia ranges from 10 to 40%. It is performed

when no distal vessels suitable for grafting are present, or in

neurologically impaired or non-ambulatory patients. There-

fore patients with chronic leg ischaemia (CLI) face a gloomy

future. Long-term survival with CLI is signiﬁcantly lower

than that of a matched population (Bertle et al. 1999).

Although patients receiving revascularization have a better

chance of longterm improvement from CLI after surgery,

there is noimprovement in survivalor limbsalvage compared

to those in whom surgery was deemed unnecessary (Pana-

yiotopoulos etal. 1997).Moreover, thereis ahigh mortalityin

this heterogeneous group of patients with CLI,reaching upto

30% at one year. Limb salvage is, however, of more impor-

tance to these patients, and this is known to exceed vessel

patency. The most plausible explanation for this is that

healing of ulcers and/or infection will reduce the oxygen

demand. Fromthisperspective, anyperipheral bypassforCLI

is a supportive ‘‘temporary’’ bypass.

Although bypass surgery is performed frequently, there

is still limited evidence for its effectiveness (Leng et al.

2002). Infrapopliteal bypass surgery is also a demanding

procedure requiring high surgical skill and experience in a

patient group with poor long-term survival. A less, or

minimally, invasive therapy such as subintimal PTA with

equivalent results could, therefore, be a desirable alterna-

tive. Furthermore, even after a failed PTA, all surgical

options remain open.

3.2 Equipment

The important items of equipment to be considered are

sheaths, guidewires, angioplasty balloons and stents.

Although the latter are not used routinely, they are occa-

sionally required to treat complications. A state-of-the-art

angiography suite is also required (see ‘‘Equipment and

Environment’’).

Crural Arterial Interventions 83

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Sheaths: Most procedures can be performed through a

ﬁve Fr sheath, although if placing a stent, a six Fr sheath is

required. Sheaths with a marker-tip have advantages, but

the most important quality is kink resistance for antegrade

use.

Guide wires: Either 0.035

, 0.018 or 0.014

may be used.

Hydrophilic guidewires can be invaluable for crossing dif-

ﬁcult stenoses.

Angioplasty balloons: Standard ﬁve French balloons can

be used, although three French systems are also available.

In the author’s experience the most commonly used balloon

diameter is 3 mm. Coronary cutting balloons may also be

helpful in treating rigid stenoses and drug-eluting balloons

show promise in this area.

Stents: Speciﬁc stents are available for use in the run-off

vessels, including absorbable metal stents. Some workers

also use coronary stents in this area.

Closure: Closure devices are used more and more, as

they may help to prevent retroperitoneal bleeding, which is

a well-known complication from an antegrade puncture.

However, this is not currently supported by the literature

(see ‘‘Sites of Arterial Access and the Role of Closure

Devices in Percutaneous Arterial Intervention’’).

3.3 Basic Technique

Crural artery recanalisation is best performed through an

antegrade puncture of the common femoral artery.

Approaching crural vessels from a contralateral approach is

very cumbersome, requires PTA balloons with long shafts

and makes the management of any complications consid-

erably more difﬁcult.

Obesity can be a problem with antegrade puncture of the

common femoral artery, but direct US-guided puncture of

the superﬁcial femoral artery in combination with a closure

device has been shown to be safe (Gutzeit et al. 2011). After

entry into the superﬁcial femoral artery angiography should

be performed to delineate the femoro-popliteal segment.

Any inﬂow problems should be treated ﬁrst to establish

optimal inﬂow to the lower leg arteries. Then angiography

with the catheter in the distal popliteal artery should be

performed. Anteroposterior and lateral views are obtained

of the calf. Angiography of the foot is performed in the

lateral and caudo-cranial projections, the latter being opti-

mal for demonstrating the plantar arch. Based on this

information a plan is made regarding which vessels should

be recanalised. Vessels going to the target area, according to

the angiosome theory should be treated ﬁrst (Alexandrescu

et al. 2011). Vessels with potentially good outﬂow are given

higher priority for treatment as they will have better

patency.

Short lesions, as in atherosclerosis, can be passed with a

0.14

–0.18

wire. Dilation with a rapid exchange balloon

can then be undertaken. In longer and often more calciﬁed

vessels, the more fragile low proﬁle wires will be easily

damaged. Larger diameter (0.35

) glide-wires can be very

helpful in this situation, as they provide a greater level of

support. Until the level of the ankle either transluminal or

subintimal recanalisation can be performed.

Lesions in this territory may need a more rigid balloon

catheter to pass over the wire to pass the often densely

calciﬁed lesions. There is a special balloon catheter with a

high pushability available (Spaargaren et al. 2009).

The normal diameter of a crural vessel is 3 mm or less

and it is important not to over-dilate. From the ankle to the

foot, and within the foot itself low proﬁle guidewires and

catheters are preferred. Fastidious prevention of spasm is

also required when entering the foot.

3.4 Techniques in Specific Aetiologies

3.4.1 Endovascular Treatment in the Diabetic

Foot

Every patient with a DF should be investigated for PAD. It

is often possible to rule out PAD by the simple palpation of

the foot pulses. If there is uncertainty then the Ankle/Bra-

chial index (ABI) should be measured with a result of \0.9

being considered suspicious for PAD. It should, however,

be remembered that the ABI can be falsely elevated in

diabetes. Diagnostic imaging is only required if revascu-

larisation is to be considered.

When one accepts the concept that disease in DF prob-

lems is long standing and that an imbalance of the equi-

librium between inﬂow of blood and the oxygen demand in

the foot needs to be corrected, it follows that the way to

treat these patients is different from treatment of athero-

sclerotic disease. The skin lesion increases the demand for

oxygen, thus disrupting the equilibrium leading to a relative

deﬁciency of blood and oxygen supply, which is needed for

normal skin healing. Infection worsens the situation by

further increasing demand for blood due to the increased

metabolism in the wound.

To correct this, an increased inﬂow of blood to the lesion

is needed to support skin healing. It should be remembered,

however, that revascularisation is by no means a stand-

alone procedure and other supportive measures such as

optimal wound care are also required. For this reason the

interventional radiologist should also be clinically involved

and therefore be part of the diabetic team.

This temporary increase in blood ﬂow to the lesion to

support ulcer healing is described by some as a ‘‘temporary

84 J. Reekers

https://t.me/med1917

percutaneous bypass’’ (Reekers et al. 2002). When the

lesion is cured and the skin healed, the extra blood supply is

no longer needed to keep the skin intact. This explains why

limb salvage is always much higher than the patency of the

treated vessel.

Antegrade puncture is the optimal approach and prep-

rocedure angiography is performed. The length of the

occlusion(s) is not the most important determinant for

which vessel to start with. The vessel with the best outﬂow

and/or the vessel supplying the area where the ulcer is sit-

uated should be explored ﬁrst, as described above when

considering the angiosome concept (Fig. 3). Crossing the

lesion intraluminally with a special 0.14

recanalisation

wire should be tried ﬁrst. If this is unsuccessful a subintimal

route should be attempted using a 0.35

glide-wire, aiming

to re-enter the vessel lumen above the level of the ankle

joint. It is best to employ long balloons with an inﬂation

device adjusting the balloon diameter to the vessel diame-

ter. The upper part of the lower leg arteries is usually 3 mm

but from the ankle into the foot it will not be more than

2 mm.

Assessment of ﬂow is the best endpoint. Thus, when

good ﬂow (including outﬂow) is observed a residual ste-

nosis (even exceeding 30%) can be accepted. In DF stenting

should not be performed to achieve better anatomical result,

and even bail-out stenting is usually not an option in such

long occlusions.

3.4.2 Endovascular Treatment of Atherosclerotic

Lower Limb Ischaemia

In this group of patients durability is an important issue, as

re-occlusion of the vessel is more likely to be associated

with a recurrence of symptoms as described above. As the

lesions are often shorter than in DF, a residual stenosis of

[30% is not acceptable and in the ﬁrst instance

re-ballooning for a longer duration should be undertaken.

For short lesions drug-eluting stents have shown some

positive data, although high level evidence is still not

available. Either the 0.14

or the 0.35

platform can be used

and other technical aspects do not differ from the descrip-

tion of technique in patients with DF.

3.4.3 Endovascular Treatment of Peripheral

Embolic Disease

Embolic disease is a serious acute limb, and potentially life-

threatening situation.The embolus mayarise from a sourcein

a more proximal vessel such as an ulcerated plaque or may

come fromthe heart. Atrial ﬁbrillation is often an indicator of

a cardiacsource.Surgical embolectomyhas beenthe ﬁrst-line

treatment option for acute embolic occlusions, but the out-

come inlower legarteries, especially inalready compromised

vessels, is often suboptimal. In making the decision whether

to undertake endovascular intervention or proceed to surgery

the clinical situation is very important. Ifthe leg is still viable

percutaneous treatment should be considered, whereas if the

Fig. 3 Subintimal recanalisation for chronic crural occlusion. a Angi-

ography shows only a patent peroneal artery with multiple proximal

stenoses. b After PTA of the peroneal artery there is still relatively

poor outﬂow to the foot. c, d After subintimal recanalisation of the

anterior tibial artery there is a marked improvement in outﬂow to

the foot

Crural Arterial Interventions 85

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leg is threatened, indicated by absence of motor and sensory

function, acute surgical embolectomy should be undertaken.

The technical aspects of treatment for peripheral embolic

disease are discussed in ‘‘Thrombolysis, Mechanical Throm-

bectomy and Percutaneous Aspiration Thrombectomy’’ .

3.4.4 Endovascular Treatment of Buerger’s

Disease

This rare situation occurs due to an inﬂammation of the

vessel wall caused by an allergy to nicotine. This leads to

progressive vessel occlusion especially in the BTK arteries.

There are no signs of atherosclerosis and so-called ‘‘cork-

screw vessels’’ are a typical feature. The latter are hyper-

trophic vasa vasorum. Cessation of smoking will stop the

progression of the disease and percutaneous subintimal

revascularisation is often very straightforward and suc-

cessful in bringing about revascularisation. Surgical options

are usually limited to amputation. Successful revasculari-

sation without stopping smoking will be unsuccessful.

4 Medication

Medication for BTK interventions can be categorised into

pre- and post intervention. Further information on drugs is

given in ‘‘Drugs used in Vascular Interventional Radiology’’

Pre intervention most patients with atherosclerotic dis-

ease are on aspirin. Optimal medical treatment for sec-

ondary risk prevention, with statins and control of all risk

factors such as hypertension, diabetes and smoking should

be undertaken in all patients who are scheduled for a BTK

procedure.

During intervention all patients should receive full

anticoagulation with heparin during the procedure. In the

event of acute thrombosis during the procedure additional

abciximab can be given to treat fresh thrombus.

For BTK interventions, especially distally and in the foot,

a goodantispasmodic regimen is also essential. Localarterial

injection of nitrates, such as isosorbide dinitrate, is probably

the most potent drug available forthis purpose. Monitoring of

blood pressure and pulse is important when administering

anti-spasmodic drugs. All spasm will resolve spontaneously

with time and if spasm persists at the end of the procedure it

can be of value to leave the patient on a 24 h heparin infusion

to prevent thrombosis while vessel spasm resolves.

After the procedure, continuation of the optimal medical

treatment, including aspirin, is important. Clopidogrel for a

3-month period in addition to aspirin may be beneﬁcial in

patients with critical outﬂow. Dual anti-platelet therapy is

especially important if stenting has been performed in the

BTK vessels.

5 Conclusion

Endovascular treatment of crural artery disease can be very

valuable in the management of critical limb ischaemia.

With improved equipment it has become possible to treat

long segment disease, which has particular beneﬁts in the

treatment of the DF. Although primary patency rates can at

ﬁrst seem disappointing, these should be ignored in favour

of limb salvage rates, which are much more impressive.

Within the context of DF, ulcer healing is likely to be

maintained even if vessel re-occlusion occurs, in accor-

dance with the concept of the ‘‘temporary bypass’’. If vessel

re-occlusion occurs on a background of atherosclerotic

disease it is more likely that symptoms will recur.

References

Alexandrescu V, Vincent G, Azdad K et al (2011) A reliable approach

to diabetic neuroischemic foot wounds: below-the-knee angio-

some-oriented angioplasty. J Endovasc Ther 18(3):376–387

Aune S, Amundsen SR, Trippestad A (1996) The inﬂuence of age on

long-term survival pattern of patients operated on for lower limb

ischaemia. Eur J Vasc Endovasc Surg 12:214–217

Bertele V, Roncaglioni MC, Pangrazzi J et al (1999) Clinical outcome

and its predictors in 1560 patients with critical leg ischaemia.

Chronic Critical Leg Ischaemia Group. Eur J Vasc Endovasc Surg

18:401–410

Cavillon A, Melliere D, Allaire E et al (1998) Are femoro-infrapop-

liteal bypasses worthwhile for limb salvage? J Cardiovasc Surg

39:267–272

Faglia E, Mantero M, Caminiti M et al (2002) Extensive use of

peripheral angioplasty, particularly infrapopliteal, in the treatment

of ischaemic diabetic foot ulcers: clinical results of a multicentric

study of 221 consecutive diabetic subjects. J Intern Med

252:225–232

Flueckiger F, Lammer J, Klein GE (1992) Percutaneoustransluminal

angioplasty of cruralarteries. Acta Radiol 33:152–155

Gutzeit A, Graf N, Schoch E et al (2011) Ultrasound-guided antegrade

femoral access: comparison between the common femoral artery

and the superﬁcial femoral artery. Eur Radiol 21:1323–1328

Hauser H, Bohndorf K, Wack C et al (1996) Percutaneous transluminal

angioplasty (PTA) of isolated crural arterial stenoses in critical

arterial occlusive disease. Rofo 164:238–243

Horvath W, Oertl M, Haidinger D (1990) Percutaneoustransluminal

angioplasty of crural arteries. Radiology 177:565–569

Leng GC, Davis M, Baker D (2002) Bypass surgery for chronic lower

limb ischaemia. Cochrane Database Syst Rev. (3):CD002000

Panayiotopoulos YP, Tyrrell MR, Owen SE et al (1997) Outcome and

cost analysis after femorocrural and femoropedal grafting for

critical limb ischaemia. Br J Surg 84:207–212

Panneton JM, Gloviczki P, Bower TC et al (2000) Pedal bypass for

limb salvage of diabetes on long-term outcome. Ann Vasc Surg

14:640–647

Prompers L, Schaper N, Apelqvist J et al (2008) Prediction of outcome

in individuals with diabetic foot ulcers: focus on between

individuals with and without peripheral vascular disease. The

EURODIALE study. Diabetologia 51:747–755

86 J. Reekers

https://t.me/med1917

Reekers JA (2002) Percutaneous intentional extraluminal (subintimal)

revascularization (PIER) for critical lower limb ischemia: too good

to be true? J Endovasc Ther 9:419–421

Roder OC, Jensen LP, Schroeder TV et al (1997) Vena saphena magna

in situ bypass to the ankle and foot. A prospective assessment of

results of 101 procedures in 94 patients with threatening amputa-

tion. Ugeskr Laeger 159: 4846–4849

Schwarten DE,CutcliffWB (1988) Arterial occlusive diseasebelow the knee:

treatment with percutaneous transluminal angioplasty performed with

low-proﬁle catheters and steerable guide wires. Radiology 169:71–74

Spaargaren GJ, Lee MJ, Reekers JA et al (2009) Evaluation of a new

balloon catheter for difﬁcult calciﬁed lesions in infrainguinal

arterial disease: outcome of a multicenter registry. Cardiovasc

Intervent Radiol 32(1):132–135

Crural Arterial Interventions 87

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Thrombolysis, Mechanical Thrombectomy

and Percutaneous Aspiration Thrombectomy

Gerard S. Goh, Robert Morgan, and Anna-Maria Belli

Contents

1 Introduction.......................................................................... 89

2 Pharmacological Thrombolysis .......................................... 89

2.1 Indications.............................................................................. 90

2.2 Contraindications to Thrombolysis....................................... 90

2.3 Technique of Intra-Arterial Thrombolysis............................ 91

2.4 The Results of Thrombolysis in Peripheral Arteries ........... 92

2.5 The Results of Thrombolysis in Peripheral Veins ............... 93

3 Percutaneous Thrombectomy............................................. 93

3.1 Indications.............................................................................. 93

4 Percutaneous Aspiration Thrombectomy ......................... 94

4.1 Equipment.............................................................................. 94

4.2 Technique............................................................................... 94

4.3 Results of PAT ...................................................................... 94

4.4 Complications of PAT........................................................... 95

5 Mechanical Thrombectomy ................................................ 95

5.1 Thrombus Fragmentation Devices ........................................ 95

5.2 Devices Which Both Fragment and Extract Thrombus....... 95

5.3 Ultrasonic Catheters .............................................................. 96

5.4 Peripheral Arterial Technique............................................... 96

5.5 Complications of Mechanical Thrombectomy ..................... 96

5.6 Results of Mechanical Thrombectomy................................. 97

6 Conclusion ............................................................................ 97

References...................................................................................... 98

Abstract

Over the past 25 years there have been many develop-

ments in the percutaneous minimally invasive dissolu-

tion and removal of thrombus from the vasculature.

Available methods include lysis by drugs, which enhance

the body’s native thrombolytic system, and those which

involve physical maceration and/or removal of clot. This

chapter will focus in particular on the use of these

techniques in acute arterial ischaemia. Surgical options

in this condition include balloon embolectomy, bypass

grafting and primary amputation. This cohort of patients

frequently has much comorbidity and percutaneous

methods offer a potentially less invasive option.

1 Introduction

Over the past 25 years there have been many developments

in the percutaneous minimally invasive dissolution and

removal of thrombus from the vasculature. Available

methods include lysis by drugs, which enhance the body’s

native thrombolytic system, and those which involve

physical maceration and/or removal of clot. This chapter

will focus in particular on the use of these techniques in

acute arterial ischaemia. Surgical options in this condition

include balloon embolectomy, bypass grafting and primary

amputation. This cohort of patients frequently has much

comorbidity and percutaneous methods offer a potentially

less invasive option.

2 Pharmacological Thrombolysis

Thrombolytic agents have now been part of routine clinical

practice for almost three decades. In this time they have

found application in the peripheral and in particular car-

diac vasculature. The ﬁrst thrombolytic agent available for

G. S. Goh (&)  R. Morgan  A.-M. Belli

Department of Radiology, St George’s Hospital, Blackshaw

Road, London, SW17 0QT, UK

e-mail: Gerard.Goh@stgeorges.nhs.uk

M. G. Cowling (ed.), Vascular Interventional Radiology, Medical Radiology. Diagnostic Imaging,

DOI: 10.1007/174_2012_568, Ó Springer-Verlag Berlin Heidelberg 2012

https://t.me/med1917

clinical use was Streptokinase, named after the haemolytic

streptococci which produce it. Its ﬁrst reported intra-arterial

use was in a patient with acute leg ischaemia (Dotter et al.

1974). Streptokinase provokes antibody formation to cata-

lyse systemic ﬁbrinolysis, and repeated administration may

result in allergic reactions or lack of efﬁcacy. Second-gen-

eration selective agents such as Alteplase (TPA) (Actilyse;

Boehringer Ingelheim, Bracknell, Berks) and Reteplase

(RPA) (Rapilysin; Roche, Welwyn Garden City, Herts) have

replaced streptokinase for peripheral applications. Reteplase

has a half-life of14 minutes, almostthree to four timesthat of

Alteplase, and so for some indications may be given as a

bolus rather than continuous infusion. However, a systematic

review of large cardiac trials in 2003 showed that outcome

was independent of choice of thrombolytic agent (Dunbar

et al. 2003). Third-generation selective agents such as Ten-

ecteplase are used in acute myocardial infarction and its role

in peripheral arterial thrombolysis is yet to be examined.

Plasmin has again become of interest in thrombolysis as

when ﬁrst studied 50 years ago it was an impure preparation.

With the current technology in preparation of pure plasmin

and catheter directed drug delivery, plasmin has been

re-discovered as a potentially valuable agent. Plasmin is

currently undergoing Phase 2 trials for use in peripheral

arterial and graft occlusion.

2.1 Indications

2.1.1 Arterial

Peripheral thrombolysis is indicated in acute myocardial

infarction, massive pulmonary embolus causing cardiovas-

cular embarrassment and in selected cases of ischaemic

stroke.

Acute limb threatening ischaemia is the most common

indication for catheter directed thrombolysis. It may result

from in situ thrombosis in vessels with pre-existing ather-

oma, embolism to previously normal lower limb vessels or

bypass graft thrombosis. In situ thrombosis of previously

diseased vessels is more likely if there is a previous history

of intermittent claudication. In cases of peripheral emboli-

sation there will be no antecedent history of claudication but

there may have been a recent myocardial infarction or

history of atrial ﬁbrillation as a potential source of emboli.

Thrombosis of lower limb bypass grafts, both prosthetic and

autogenous vein, may also be treated with thrombolysis,

although success with vein grafts is unlikely following more

than 72 h of thrombosis (Belkin et al. 1990). Due to the

severity of possible complications treatment should be

limited to patients with threatened but viable limbs (Ruth-

erford grades IIA and IIB) (Kessel et al. 2004).

Special mention must be made of thrombosed popliteal

aneurysms. Thrombolysis of these may lead to massive

distal embolisation. Thrombolysis does, however, have a

role when the run-off vessels are thrombosed. A catheter is

advanced distal to the aneurysm allowing thrombolysis of

the runoff prior to surgical bypass of the aneurysm. Acute

upper limb ischaemia as well as thrombosis of mesenteric

(Pillari et al. 1983) and renal arteries (Rudy et al. 1982) are

treatable with thrombolysis.

2.1.2 Venous

The use of systemic thrombolysis in deep venous throm-

bosis (DVT) is aimed at restoring venous patency and

preserving valvular competence and thus reducing the

incidence of post-thrombotic venous insufﬁciency (Kessel

and Patel 2005). This indication is currently controversial

given the potential side effects of thrombolysis. A review of

12 randomised trials comparing thrombolysis with antico-

agulation for DVT found that thrombolysis signiﬁcantly

reduced post-thrombotic syndrome and improved venous

function at follow-up. This was, however, at the expense of

increased bleeding complications and two strokes out of

668 patients (Watson and Armon 2004). Systemic throm-

bolysis requires close CCU monitoring for hours or days

and generally is not recommended for treatment of DVT

(Vedantham et al. 2009).

One clear indication for venous thrombolysis is phleg-

masia caerulea dolens. In this rare condition there is

extensive venous thrombosis resulting in arterial compro-

mise and limb loss if not treated promptly (Centeno et al.

1999). Thrombolysis is administered by both arterial and

venous catheters in this situation.

Spontaneous or effort-related thrombosis of the sub-

clavian vein, the Paget-Schroetter syndrome, results from

hypertrophy of the subclavius and scalenus anterior mus-

cles. Treatment of the condition is by a combination of

thrombolysis followed by venoplasty and resection of the

ﬁrst rib (Divi et al. 2005). Thrombolysis of dialysis access

ﬁstulae is used as an alternative to open or percutaneous

thrombectomy (see ‘‘Dialysis Access Management’’).

2.2 Contraindications to Thrombolysis

Absolute:

I Cerebrovascular event within the last 2 months

I Active bleeding diathesis

I Recent gastrointestinal bleeding (within 10 days)

I Neurosurgery/intracranial trauma within the last 3 months

I Presence or development of compartment syndrome

Relative:

I Major surgery/trauma/cardiopulmonary resuscitation

(within 10 days)

I Uncontrolled hypertension (systolic[180 mmHg, diastolic

[110 mmHg)

90 G. S. Goh et al.

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I Puncture of non-compressible vessel

I Recent eye surgery

I Neurosurgery within past 3 months

I History of severe contrast allergy or hypersensitivity

I Intracranial trauma within 3 months

I Recent internal or noncompressible hemorrhage

I Hepatic failure, particularly in cases with coagulopathy

I Life expectancy \1 year

I Diabetic retinopathy

I Hepatic failure

I Pregnancy/post partum status

I Bacterial endocarditis.

2.3 Technique of Intra-Arterial Thrombolysis

A recent Cochrane review (Kessel et al. 2004) of peripheral

thrombolysis concluded that systemic intravenous throm-

bolysis should not be used as it is associated with poor

clinical outcomes and a higher bleeding rate than local

infusion. Local catheter directed thrombolysis aims to

deliver the maximum concentration of lytic agent into the

thrombus with the minimum systemic side effects. Pre-

thrombolysis imaging should ideally be non-invasive

(duplex/computed tomography/magnetic resonance angi-

ography), thus avoiding unnecessary arterial punctures.

However, if conventional angiography is required the radial

artery approach has been shown to be safe prior to lysis

(Cowling et al. 1997). If thrombus is present at or above the

level of the common femoral bifurcation deﬁnitive access

from the contralateral side and a crossover technique is

employed. For more distal disease antegrade access pro-

vides the most straightforward route. If it is possible to pass

a guidewire through the length of the thrombus this is

thought to predict a favourable response to thrombolysis

(Working Party on Thrombolysis in the Management of

Limb-Ischaemia 2003).

In prosthetic grafts that have thrombosed, direct graft

puncture, with concurrent administration of antibiotics prior

to puncture, has been shown to be safe and effective

(Cowling et al. 1996). It may be difﬁcult to ﬁnd entry to and

cannulate the afferent or efferent ends of the graft endolu-

minally as there may be underlying stenoses. Direct graft

puncture should not be performed in vein grafts.

The catheter should then be embedded within the throm-

bus for drug delivery. A number of different thrombolysis

drugs may beused suchastPA, urokinase,alteplase, reteplase

or tenecteplase (Karnabatidis et al. 2011). Streptokinase

should not be used in everyday clinical practice, because it is

proved less effective and more antigenic (Robertson et al.

2010). Thrombolysis may be given as a continuous low dose

infusion, for example tPA 0.5–1.0 mg/h. Alternatively, an

accelerated technique may be employed. Up to three initial

boluses of 5 mg tPA are given at 10-minute intervals over

30 minutes, followedby an infusion of 3.5 mg/h for 4 h, then

0.5 mg/h (Braithwaite et al. 1997). The accelerated method

does signiﬁcantly decrease the time required to restore ﬂow,

so may be indicated in patients with severe ischaemia and

neurosensory deﬁcit, whose limbs will not remain viable if

perfusion is not restored rapidly. A combination of the two

methods maybe employed, with an initial bolus of5 mg TPA

followed by a low dose infusion. Finally the pulsed spray

technique uses a pump toperiodicallyinjectsmall volumes of

thrombolytic through a multiple side hole catheter, thus

combining chemical and mechanical disruption of thrombus

(Buckenham et al. 1992). The available data suggests, how-

ever, that vessel patency and limb salvage rates are inde-

pendent of the individual technique or thrombolytic agent

used (Thomas and Gaines 1999; Kessel et al. 2004; Kessel

and Patel2005). Angiography shouldbe performed at regular

intervals to assess clot dissolution andallow the catheter to be

repositioned within the thrombus as required. The infusion

should beterminated when ﬂow is restored, if there is clinical

deterioration in the limb in the absence of evidence of

continued lysis or if there has been no progress in lysis since

the lastangiogram. Distal embolization may occurduring the

thrombolysis and should be expected. The limb often

becomes more painful and deteriorates clinically, but so long

as there is no evidence of haemorrhage, the infusion should

continue until the distal thrombus has lysed. Following

successful lysis, underlying stenotic lesions must be sought

and treated (Fig. 1). The reported 24-month vessel patency

rates after thrombolysis was 79% after the underlying lesion

was identiﬁed and treated versus 9.8% when not treated

(Sullivan et al. 1991). If no causative factor is found,

long-term anticoagulation should be considered as otherwise

patency rates are extremely poor (Hall et al. 2001).

Thrombolytic agents only act on ﬁbrin. They have the

capacity to prevent new thrombus formation. For this

reason heparin or anti-platelet agents may be given in

combination with thrombolysis. There is no ﬁrm data on the

relative risks and beneﬁts of heparin during thrombolysis

(Working Party on Thrombolysis in the Management of

Limb Ischaemia 2003), but many practitioners use it in the

hope of reducing access site and peri-catheter thrombosis.

Coronary trials have demonstrated the safety and efﬁcacy

of the glycoprotein IIb/IIIa receptor inhibitor Abciximab.

However, as yet there are no studies of signiﬁcant power to

support its use in the peripheral circulation (Kessel et al.

2004). After sheath removal, the use of a vascular closure

device should be considered, if feasible. However, no

reports from randomised, controlled studies have investi-

gated the safety and efﬁcacy of the use of arterial closure

devices compared with classic manual compression,

following procedures with such a high bleeding risk (Ouriel

et al. 1994).

Thrombolysis, Mechanical Thrombectomy and Percutaneous Aspiration Thrombectomy 91

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2.4 The Results of Thrombolysis in Peripheral

Arteries

A recent systematic review that included a meta-analysis of

ﬁve large randomised controlled trials with a total of 1,283

patients comparing surgery with thrombolysis in the man-

agement of acute lower limb ischemia showed no signiﬁ-

cant difference between them in terms of limb salvage or

death at 30 days, 6 months or 1 year. However, hemor-

rhagic complications and distal embolisation were more

likely at 30 days in patients undergoing thrombolysis

compared to surgery (8.8 vs. 3.3% and 12.4 vs. 0%

respectively) (Berridge et al. 2002).

Ouriel et al. (1994) randomised 114 patients with severe

ischaemia (Rutherford grade IIb) of mean duration 2 days to

either surgery or thrombolysis. The limb salvage rate was

identical for both groups (82% at 12 months). However, the

cumulative survival rate was signiﬁcantly better in the throm-

bolysis group (84 vs. 58%). The authors found that the

difference in survival related to an increased cardiovascular

mortality in the surgical arm within 30 days.

The Surgery or Thrombolysis for Ischemic Lower

extremity (STILE) trial (The STILE Investigators 1994)

prospectively randomised 393 patients with non-embolic

arterial or graft related lower limb ischaemia to lysis or

surgery. The trial was halted because although amputation-

free survival was similar at 6 months (82.3% surgery vs.

82.9% thrombolysis), patients treated with thrombolysis had

signiﬁcantly higher levels of continued or recurrent

ischaemia. The trial has been subsequently criticised due to

the high level of failure of catheter placement in the

thrombolysis group; these were categorised as treatment

failures. This has led commentators to suggest that some of

the radiologists involved with the study were not familiar

with the technique. The study also included many patients

with ischaemia of more than 2 weeks’ duration. When

stratiﬁed for duration of ischaemia, patients with symptoms

for between 0 and 14 days had lower amputation and

mortality rates with thrombolysis. Patients with symptoms

of greater than 14 days’ duration fared better with surgery.

In thrombolysis patients who subsequently required surgery,

58% had a reduction in the complexity of procedure.

The Thrombolysis or Peripheral Arterial Surgery (TO-

PAS) trial (Ouriel et al. 1998) randomised 544 patients with

acute embolic or thrombotic occlusions of the lower limb to

thrombolysis or surgery as their initial management.

Amputation-free survival was not signiﬁcantly different for

surgery or thrombolysis at 1 year follow-up (69.9 and 65%,

respectively). Although there was no difference in the

mortality ﬁgures there was an excess of bleeding compli-

cations in the lysis group (12.5 vs. 5.5% for surgery). In the

subsequent 6 months, patients in the surgical arm required

an additional 551 open surgical procedures compared with

only 315 in the lysis group. In the same time period 31.5%

of the thrombolysis patients were alive without amputation

having only had a percutaneous procedure.

Fig. 1 Graft Thrombolysis. a Angiogram in a patient with a 2-day-old

occlusion of a femoropopliteal vein graft. The graft is completely

occluded. b, c Post 22 h of thrombolysis via the contralateral femoral

artery ﬂow has been restored within the graft. Proximal (black arrow)

and distal (white arrow) anastomotic strictures have been unmasked.

d, e Post angioplasty the strictures have been abolished (arrows)

92 G. S. Goh et al.

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