283 EMBOLECTOMY IN THE LIMB ARTERIES DAVID J. TIBBS, M.C., M.S.(LOND.), F.R.C.S. Department of Surgery, Royal Victoria Infirmary, Newcastle upon Tyne Embolism to the limb arteries is usually a con- dition which is best treated by conservative means but there are a number of cases in which failure to reopen the occluded circulation may lead to loss of the limb and indeed loss of life. The increased confidence with which surgeons operate upon arteries and the facility with which extensive lengths of arteries may be cleared of clot have brought about a decided improvement in the prospect of saving the limb and preserving good function; however, the overall mortality of the general condition giving rise to embolism remains high and it might be said that surgical progress has not been matched by medical progress in this field. In this paper it is proposed to outline our policy towards major arterial embolism in the vessels to the limbs and to present some indication of the results which this policy may bring. The Origin and Significance of Arterial Emboli In this article we are not concerned with lesser emboli but with those of sufficient size to occlude the main arterial supply to a limb or, when the aorta is involved, to both lower limbs. In Tables I and 2, experience with 27 such cases treated on the Professorial Surgical Unit of the Royal Vic- toria Infirmary is summarized. Mitral stenosis with auricular fibrillation is the commonest single cause, but the detachment of a mural thrombus following a coronary thrombosis is almost as common. Occasionally a massive arterial embolus appears without obvious source, although in these patients it usually transpires that the embolus took origin in the heart as a result of a damaged myocardium. There are, of course, other possible origins for an embolus but these do not usually create a need for surgical interference. Enough has been said already to make clear one point which is of the greatest importance in the manage- ment of major arterial limb embolism; most of the patients suffer from some form of heart disease and the embolus is a mere, although perhaps dangerous, complication of what may be a very serious cardiac state. For this reason, surgery should only be used in arterial embolism to save a limb which would otherwise inevitably become gangrenous and create an added threat to the patient's life; incidentally, with an embolus of this magnitude the patient's general condition will often improve after the circulation has been reopened. Particularly dangerous is the state of the patient who has developed massive embolism after a coronary thrombosis. Table i shows that six out of ten of our patients showing this combination died from heart failure even though in most a satisfactory circulatory equilibrium had been reached after the operation. In this class of patient surgery must never be employed without the most pressing indications. Symptoms and Signs of Severe, Extensive Ischaemia The patient can usually tell to the minute when the embolus arrived; this and the absence of preceding intermittent claudication help in the distinction between embolism and local throm- bosis within a diseased artery. The initial pain soon wears off and is replaced by numbness. Examination shows pallor or mottling of the skin, the pulses are absent below the embolus and the limb will gradually become cold. These changes, however, do not tell us whether the limb has sufficient circulation left to survive. A danger- ously severe ischaemia gives rise to cutaneous anaesthesia of a ' stocking and glove' distribution and this is a most valuable prognostic guide. A limb showing extensive anaesthesia persisting for more than two or three hours, in spite of con- servative treatment, is in very real danger. Another sign may be added to this: the muscles involved may become swollen, tender and con- tracted and stretching them causes severe pain. This state is characteristic of muscle which has lost its blood supply and is analogous to rigor mortis. Its appearance, although perilously late, does not necessarily indicate a hopeless situation (Fig. i); it is a sign that massive muscle death is imminent or has actually occurred; the state of the Hl by copyright. on February 18, 2022 by guest. Protected http://pmj.bmj.com/ Postgrad Med J: first published as 10.1136/pgmj.36.414.283 on 1 April 1960. Downloaded from
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283
EMBOLECTOMY IN THE LIMB ARTERIESDAVID J. TIBBS, M.C., M.S.(LOND.), F.R.C.S.
Department of Surgery, Royal Victoria Infirmary, Newcastle upon Tyne
Embolism to the limb arteries is usually a con-dition which is best treated by conservative meansbut there are a number of cases in which failureto reopen the occluded circulation may lead to lossof the limb and indeed loss of life. The increasedconfidence with which surgeons operate uponarteries and the facility with which extensivelengths of arteries may be cleared of clot havebrought about a decided improvement in theprospect of saving the limb and preserving goodfunction; however, the overall mortality of thegeneral condition giving rise to embolism remainshigh and it might be said that surgical progresshas not been matched by medical progress in thisfield. In this paper it is proposed to outline ourpolicy towards major arterial embolism in thevessels to the limbs and to present some indicationof the results which this policy may bring.
The Origin and Significance of ArterialEmboli
In this article we are not concerned with lesseremboli but with those of sufficient size to occludethe main arterial supply to a limb or, when theaorta is involved, to both lower limbs. In TablesI and 2, experience with 27 such cases treated onthe Professorial Surgical Unit of the Royal Vic-toria Infirmary is summarized. Mitral stenosiswith auricular fibrillation is the commonest singlecause, but the detachment of a mural thrombusfollowing a coronary thrombosis is almost ascommon. Occasionally a massive arterial embolusappears without obvious source, although in thesepatients it usually transpires that the embolustook origin in the heart as a result of a damagedmyocardium. There are, of course, other possibleorigins for an embolus but these do not usuallycreate a need for surgical interference. Enoughhas been said already to make clear one pointwhich is of the greatest importance in the manage-ment of major arterial limb embolism; most ofthe patients suffer from some form of heartdisease and the embolus is a mere, althoughperhaps dangerous, complication of what may bea very serious cardiac state. For this reason,
surgery should only be used in arterial embolismto save a limb which would otherwise inevitablybecome gangrenous and create an added threatto the patient's life; incidentally, with an embolusof this magnitude the patient's general conditionwill often improve after the circulation has beenreopened.
Particularly dangerous is the state of the patientwho has developed massive embolism after acoronary thrombosis. Table i shows that six outof ten of our patients showing this combinationdied from heart failure even though in most asatisfactory circulatory equilibrium had beenreached after the operation. In this class ofpatient surgery must never be employed withoutthe most pressing indications.
Symptoms and Signs of Severe, ExtensiveIschaemiaThe patient can usually tell to the minute
when the embolus arrived; this and the absenceof preceding intermittent claudication help in thedistinction between embolism and local throm-bosis within a diseased artery. The initial painsoon wears off and is replaced by numbness.Examination shows pallor or mottling of the skin,the pulses are absent below the embolus and thelimb will gradually become cold. These changes,however, do not tell us whether the limb hassufficient circulation left to survive. A danger-ously severe ischaemia gives rise to cutaneousanaesthesia of a ' stocking and glove' distributionand this is a most valuable prognostic guide.A limb showing extensive anaesthesia persistingfor more than two or three hours, in spite of con-servative treatment, is in very real danger.Another sign may be added to this: the musclesinvolved may become swollen, tender and con-tracted and stretching them causes severe pain.This state is characteristic of muscle which haslost its blood supply and is analogous to rigormortis. Its appearance, although perilously late,does not necessarily indicate a hopeless situation(Fig. i); it is a sign that massive muscle death isimminent or has actually occurred; the state of the
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FIG. i.-Photograph of clot removed by retrograde flushing; this formed acast of the arterial tree from the common femoral artery, down to thedivision of the popliteal arterv; the tails corresponding to the tibial arteriesand the profunda femoris can be seen. Embolism had occurred 24 hoursbefore embolectomy; the limb, prior to operation, had shown anaesthesiaup to the knee and the calf muscles w,ere swollen and contracted. Theappearances of the limb on the day following operation are also shownswelling and contracture of the calf muscles is still present and the skinshows a blotchy erythema. This limb recovered almost completelv withvirtual disappearance of the muscle changes although the tips of twosmall toes became gangrenous. The patient had had a series of coronarythromboses and he died of heart failure six weeks after enmbolectomy.
corresponding hand or foot is usually equallycritical.The decision for surgery can usually be based
on the index of severity of ischaemia provided bythe extent of anaesthesia and the presence ofmuscle contracture.
The Time FactorIf a tourniquet is applied to a limb, anaesthesia
develops within an hour and ischaemic contractureof the muscle after about six to eight hours.Restoration of the circulation after this period isunlikely to save the limb and there is a very realrisk of ' touniquet shock ' or other manifestationssuch as anuria. The march of events with arterialocclusion by an embolus is not usually so rapid orrelentless as this, however, because the ischaemia
is seldom absolute and the veins remain open(although extensive venous thrombosis may super-vene). The collateral circulation even in severecases will usually provide some contribution, thevalue of which can be assessed fairly accurately bynoting the severity of the signs of ischaemia in thelimb and especially the extent of the sensory loss.Initially the collateral circulation may be impededby spasm but, after an hour or two, this maywear off and a corresponding improvement occur;improvement may also occur through actual shift-ing of the embolus. In this respect the lapse oftime may prove an advantage but, on the otherhand, particularly when collaterals are poor, andthe flow they supply is meagre, consecutivethrombosis in the stagnant blood within theartery often occurs so that the situation is further
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At the same site as original embolus and withina few days (possibly incomplete clearanceat first operation) .. .. .. 3*
At a different site (carotid) .. .. IAt a different site and two years later (bilateral
femoral and aortic bifurcation-mitralstenosis and fibrillation) .. .. .. Iit* Two patients left hospital alive and with both limbs
satisfactory.f Excellent result to both operations.Many episodes of minor embolism, not requiring
operation, were seen at all stages of recovery.
aggravated. Fortunately this unfavourable aspectof the time factor can be minimized by use ofheparin without prejudice to surgical treatment.
It used to be thought that surgical removal ofan embolus was unlikely to give a patent artery ifthe procedure were not undertaken within a fewhours of onset. This is not true because clot canbe removed days or even weeks later to give anartery which will remain patent provided itsperipheral outflow is not impeded by inadequateclearance of clot.6 (In nearly every case sum-marized in Table 2 the main artery remainedopen and pulsatile after embolectomy and anyresidual ischaemic symptoms arose from occlusionof the lesser arteries.) It is true, however, thatwithin 24 hours the consecutive thrombus issupple and has relatively good resistance to frag-mentation so that it may be withdrawn quiteeasily; later the clot becomes more firm, brittleand slightly adherent so that technically it is moredifficult to withdraw it by any means from theside branches. In this respect thIe sooner embolec-tomy is undertaken, the more complete will besuccess in restoring circulation to that limb; lateembolectomy may well be successful but willinvolve a more complex and extensive operation.
It is permissible to spend an hour or two inassessment of a limb and in making sure that,under favourable conditions, spontaneous im-provement is not going to occur. If the per-sistence of anaesthesia makes it clear that surgeryis obligatory in order to save the limb, thenfurther time should not be lost.
Contraindications to SurgeryThe ischaemia is not of sufficient severity. Colour,
warmth and sensation or the presence of a poplitealpulse or brachial pulse at the elbow may allindicate that the limb will survive. It is seldomjustifiable to undertake emergency surgery forembolism merely to avoid claudication. Thiscondition can be relieved at a later stage ifnecessary.
Ischaemia has been present for too long. Stainingof the skin over any sizable area, a line of demar-cation, extensive calf muscle contracture, theknowledge that the condition developed 12 ormore hours previously are all factors which maywell add up to contraindicate embolectomy be-cause extensive tissue death has already occurred.This is not an easy decision; at least five patientsin our series were operated upon with successwhen the limbs were apparently irrecoverable.The limb after operation, under these circum-stances, becomes oedematous; skin erythema andblistering may develop and possibly small gan-grenous patches, especially on the toes, but inspite of this, in favourable cases, slow recovery of
Summary: 20 useful limbs; I below knee amputation.
STATE OF THE LIMBS IN 12 PATIENTS DYING IN HOSPITAL
No. ofLimb state Patients Comment
Both limbs in satisfac- 8 (15 limbs At least an adequate circulation was returned to these limbs; function couldtory state at risk) not be assessed as patients were confined to bed until time of death.
Gangrene of one limb.. 4 Factors in these four cases were:Case (a): Embolectomy too late and patient too ill for adequate operation.Case (b): Recurrent ' embolism-? inadequate original clearance.Case (c): Recurrent' embolism-? inadequate original clearance.Case (d): Unrelieved occlusion of aorta.
Note.-Gangrene did not appear to contribute to the patient's death-all patients developing gangrene were vervill for other reasons and therefore further operation was prevented when renewed ischaemia became evident.
sensation will occur and eventually a useful limbis obtained.
Reopening the circulation in border-line casesis not without some risk, because there is alwaysthe theoretical danger of ' tourniquet shock' or atype of ' crush syndrome.' A massive septicnecrosis of muscle may develop due to the factthat reopening the circulation has converted adry infarction of muscle into a wet gangrene.Fortunately, however, this sort of event is rareand we believe it is permissible in cases of doubtfulviability to give embolectomy a trial.
The cardiac state. The operations of embolec-tomy under skilled general anaesthesia do notappear to offer any great immediate risk even inpatients with quite severe cardiac disease. How-ever, the embolus may be but one manifestation
in a dying patient and an operation would be anill-judged gesture. Our policy is to accept theimmediate risk of surgery if the cardiologistbelieves that the cardiac state is not in itselflikely to prove fatal and providing the alternativeis a gangrenous limb.
The Initial Management Within HospitalBlood is taken for cross-matching; io,ooo units
of heparin are given intravenously. The area ofcutaneous anaesthesia in the affected limb isaccurately mapped out and a search made formuscle contracture. A careful assessment of thecardiac state is made and the patient sedated with& gr. of omnopon.The ischaemic limb is kept cool and the rest
of the patient warmed in order to relax sympa-
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April I960 TIBBS: Embolectomy in the Limb Arteries z87
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FIG. 2.-The techniques for removal of embolus and consecutive clot. A, Localextraction. Before any clamps are applied the clot is delivered throughan arteriotomy and gently drawn upon. If the clot is recent, considerablelengths of consecutive thrombus may be extracted. B, Milking clottowards the arteriotomy. This can be very effective in exposed portionsof arteries. C, Retrograde flushing. A cannula is introduced in orderto flush forcibly the portion of the artery above it. Very extensiveconsecutive thrombus can be removed in this fashion with minimalinterference to the arteries.
thetic tone; vaso-dilator drugs may be employedbut we do not advise any intra-arterial injections.The limb should be kept in a slightly dependentposition; any elevation will further diminish theavailable blood. If complete anaesthesia is presentup to the knee or any muscle contracture ispresent, operation should be undertaken withoutdelay; in other cases the limb is watched for anhour or two. If complete sensory loss persistsabove the ankle without any significant regression,then embolectomy should be undertaken. If,however, anaesthesia has shown steady regressionso that only the forefoot is involved, then it isprobably safe to continue waiting and observingbecause the collateral circulation may be adequate.In cases such as this, the decision for or against
surgery may be difficult and in the lower limb auseful deciding factor is the presence or not of apopliteal pulse-if a pulse is present the foot willprobably survive and embolectomy is unnecessary;conversely, absence of this pulse, or more speci-fically of the femoral pulse, indicates that embo-lectomy is best undertaken. In our experience allaortic and most cases of iliac and femoral arteryembolism require surgery if the limb is to bepreserved; this accords closely with the findingsand recommendations of Jacobs.4
The OperationThe modern conception of embolectomy is that
not only should the embolus itself be removed,but also as near complete clearance of consecutive
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thrombus as is possible should be achieved; thismay involve multiple arteriotomies but the im-proved results justify this.
In the lower limbs one or more key sites alongthe artery will have to be exposed; the mostfavourable sites are the lower aorta and commoniliac arteries (transperitoneally), the commonfemoral artery, the popliteal artery (mediallybelow the knee), and the posterior tibial and thedorsalis pedis arteries at the ankle. If femoralpulsation is missing, this artery is first exposed,bilaterally if necessary. A finger passed underthe inguinal ligament alongside the artery willsoon indicate whether abdominal exposure of theaorta and iliac arteries will be necessary. In theunusual event of operation being undertaken inthe presence of an unrestricted femoral pulse, itmay be permissible to expose the popliteal arteryfirst, but in the majority of cases femoral arteryexposure is wise.
In the arm careful palpation will usually indi-cate the upper level of the embolic block andincision will be made over the artery at this level.
The Technique of Removing the Embolus andPropagated Clot
In our experience there are three effectivetechniques for removing embolus and clot fromwithin an artery (Fig. 2).
(a) Local Extraction. After exposing the upperend of the clot through an arteriotomy it is care-fully teased out of the artery and gentle tractionexerted to draw the clot from the distal part.This manoeuvre can be surprisingly successful andmay draw up an extensive cast of the mainarteries. More usually the clot breaks so that theprocedure is limited in its scope; naturally noarterial clamps should be applied until it has beenattempted for fear of prematurely breaking theclot.
(b) Milking. If it is assessed that the clot isnot extensive, the artery may be milked firmlybetween the fingers. This is very effective forclearing the portion of artery actually accessible inthe wound, but beyond this there is a tendencyto break the clot and leave portions behind sothat it is of limited value.
(c) Retrograde Flushing.'. 2, 5 7 This techniqueis of outstanding merit and should be employedwithout hesitation if it appears that removal ofclot is incomplete by the preceding method.This technique is at its best if the clot has notbeen broken up by previous manoeuvres. Theartery is exposed and cannulated at the next' favourable site ' more distally; heparinized salineis then forcibly pumped up the artery to eject theclot within it through the upper arteriotomy. Ifnecessary, the procedure is repeated from a still
lower level to clear the distal artery. Long coilsof clot in continuity appear dramatically with thistechnique and are followed by vigorous backbleeding from side channels which are opened up.In some patients we have made as many as sevenarteriotomies in the two lower limbs and removeda massive cast of the vasculature of the lowerlimb (Fig. 3).There are, of course, other techniques which
are occasionally useful, such as use of a suctiontube, use of a reamer or spirally wound wires,the binding of an Esmarch's bandage up thelimb, or forcible external compression on the lineof the arteries below the arteriotomy. Theseprocedures, however, are disappointing; they losetime and fragment clot so that usually it is lesstraumatic and far more effective to proceedstraightway to retrograde flushing when localextraction and milking have proved insufficient.The multiple arteriotomies do not take much
time and are well accepted even by the post-tibial artery.
'Spasm'If a main artery, exposed surgically, is seen to
lack pulsation and is slender in calibre, it istempting to attribute this to ' spasm.' ' Spasm'is a concept best left out of the practical con-sideration of the surgeon performing embolec-tomy upon the main limb vessels.3 In the seriessummarized in Table i many examples of ' spasm 'were encountered which resolved completely withmore thorough removal of clot from within theartery above the area of ' spasm.' Under thesecircumstances, ' spasm' is due to lack of pressureand interruption of the pulse by clot occludingthe artery at a higher level. If longitudinal pulsa-tion is seen, this signifies an artery filled with clota short distance below patent artery; the pulsationof the artery above is being transmitted in aplunger-like fashion by the clot-filled artery.
Criteria of SuccessA pulsatile flow should be obtained from above.
Vigorous back bleeding from the distal artery is agood indication that there has been reopening ofa useful part of the arterial tree. The arteriotomymay then be closed and the flow restarted and thedistal pulses palpated. At least the popliteal pulseshould have returned; if this not palpable, thenthis artery is exposed and retrograde flushingemployed, even if this means reopening the upperarteriotomy.A successful retrograde flush of course indicates
that at least the main channel is patent. Restora-tion of wrist or ankle pulses is most reassuring,but their presence is not essential for recovery; ifsufficient reopening of the circulation has been
April I960 TIBBS: Embolectomny in the Limb Arteries 289
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FIG. 3.-This patient's lower limbs were thought to bebeyond recovery as a result of a two-day-old saddleembolus. The main arteries of both limbs werecompletely occluded by thrombus extending fromaorta to the tibial arteries. Retrograde flushingwas employed through arteriotomies at the sitesindicated. The left limb regained excellent returnof function, but the right limb after recoveryshowed severe claudication due to less adequateclearance. This patient was well six months later.
accomplished, the pallor in the extremity will bereplaced by return of at least a tinge of colourand the veins will become well filled.The surgeon undertaking embolectomy must
be prepared to clear the length of the artery, withsome speed, through multiple incisions. Bloodloss is not usually very great and the patientsseem little disturbed by this procedure. If clear-ance has been thorough, anticoagulants are notnecessary in the immediate post-operative phase,indeed they add materially to the risks. It iswise, however, to put the patient on long-termanticoagulants after the first week in order tominimize further embolic episodes. The patientis encouraged in active limb movements and,whenever possible, ambulation is commenced atabout one week after the operation. In thepatients with mitral stenosis, valvotomy should begiven careful consideration as a means for pre-venting further embolism.
Immediate Recurrence of EmbolismA further ' embolism' occurring within a few
days to the same site as the original embolus ispossibly due to incomplete removal of clot at theoriginal operation. If the limb is once more injeopardy, the operation must be repeated on thesame indications as the original procedure. Thereis no special difficulty in this re-operation and inour small series this was undertaken, with success,on three occasions.A true recurrent embolism quite often does
occur to other parts of the body and must betreated on its merits even if this means furthersurgery; more usually it is a minor episode thatwill require medical treatment alone. The fol-lowing case history is a good example of theprecarious state of this class of patient and thedisappointments that may follow an outstandinginitial success.The patient, aged 6o, was admitted with a
24-hour-old common iliac embolus followingcoronary infarction. Although there was extensiveclotting below the embolus, it was successfullydealt with by retrograde flushing through multiplearteriotomies. Fourteen days later, just before hisdischarge from hospital, he developed pain in theleft eye, mental confusion and a right hemiplegia.Temporal artery pulsation was absent on the leftside. He was promptly taken to theatre where,under local anaesthetic, an embolus was removedfrom the bifurcation of the left common carotidand a long consecutive clot extracted from theoccluded internal carotid artery; pulsatile flowwas restored within an hour of onset but, althoughthere was an immediate return in mental respon-siveness, the hemiplegia persisted.
DiscussionOur experience with embolectomy is largely
confined to the lower limbs and two features ofinterest emerge. Firstly, that most lower limbs
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with major embolus can be saved by adequatesurgery provided the patient's cardiac state iscompatible with continued life; secondly, that thelapse of several days with severe ischaemia, thepresence of extensive ischaemic muscle contractureor even an early demarcation line do not neces-sarily preclude salvage of a useful limb. In thisrespect, the more extensive operations recentlyundertaken to achieve reopening of the arterialtree have been fully justified.
It is necessary to consider to what extent thehigh survival rate of the limbs in our series(Table 2) has been achieved at the cost of in-creased mortality. It is important to bear inmind that only the obviously moribund or thehopelessly late cases with well developed gangrenewere refused embolectomy and many of ourpatients had slender chances of recovery by anymeans; our surgical mortality rate could certainlyhave been more favourable if rigid selection hadbeen exercised. Table i shows that most of thepatients who succumbed lived for sufficient timeafter the embolectomy to suggest that surgery initself was an unimportant factor. There weretwo patients, however, in whom surgery apparentlyhastened death.One patient with mitral stenosis and bilateral
common iliac emboli died a few hours afteroperation and, at autopsy, it was found that shehad developed a large retroperitoneal haematoma.This case occurred early in the series and at thattime heparin was given post-operatively. Suddenblood loss is clearly most undesirable in the
cardiac invalid and this is the reason why heparinis best avoided in the immediate post-operativephase.The second patient (recent coronary throm-
bosis and aortic embolus) died on the operationtable, but if she died during an uneventful opera-tion, then she was scarcely likely to survive themassive gangrene and bilateral amputations thather ' saddle' embolus would have caused. Therewere, moreover, other factors that made her deathinevitable.
In performing embolectomy, the surgeon ismerely ensuring that a sound limb awaits thosewho will recover from the dangerous illnesswhich has caused embolism; in this way thesmall band of survivors can be spared the finalhandicap of an amputation.The embolectomies referred to above were per-
formed variously by Professor A. G. R. Lowdon,E. G. Hardy, L. B. Fleming and the author.
I am indebted to D. P. Hammersley for thedrawings.
REFERENCESCRAWFORD, E. S., and DE BAKEY, M. E. (1956), Suirgery,
40, 737-2. DYE, W. S., OLWIN, J., JAVID, H., and JULIAN, 0. C.
(195), Arch. Surg., 70, 71g.3. HARDY, E. G., and TIBBS, D. J. (I960), Brit. mned. J., awaiting
publication.4. JACOBS, A. L. (I959), 'Arterial Embolism in the Limbs.'
Edinburgh and London: Livingstone.S. LERMAN, J., MILLER, F. R., and LUND, C. C. (1930),
J. Amer. med. Ass., 94, 1128.6. OLWIN, J. H., DYE, W. S., and JULIAN, 0. C. (1953), Arch.
.S'irg., 66, 480.7. SHAW, R. S. (IqS6), Surg. Gynaec. & Obstet., 103, 279.
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