treatment - heart · totally occluded venous grafts are usu-allyless...

Br Heart J 1995;74:455-459

TECHNIQUE

Combined mechanical and thrombolytictreatment for totally occluded bypass grafts

C Lotan, M Mosseri, Y Rozenman, Y Hasin, M S Gotsman

Department ofCardiology, HassadahUniversity Hospital,Jerusalem, IsraelC LotanM MosseriY RozenmanY HasinM S GotsmanCorrespondence to:Dr C Lotan, CardiologyDepartment, HadassahUniversity Hospital, PO Box12000, Ein Kerem,Jerusalem, Israel 91120.

Accepted for publication26 April 1995

AbstractTotally occluded venous grafts are usu-

ally less amenable to mechanical reperfu-sion alone (for example percutaneoustransluminal coronary angioplasty,PTCA) because of the large mass ofthrombotic material within the graft. Acombined approach using mechanicaland thrombolytic treatment might there-fore be more successful. Twenty one

patients (20 males, one female) with a

mean age of 64-5 (SD 5.6) years under-went angiography because of crescendoor unstable angina (n = 19) or myocar-dial infarction (n = 2) at a mean of 217(18*6) days after onset of symptoms(range 1-60). All patients had had coro-

nary artery bypass grafting (CABG) at a

mean of 8-02 (4.02) years (range 0-3-13years) before the current admission. Atcatheterisation, totally occluded venous

bypass grafts to the left anterior descend-ing coronary artery or diagonal (n = 10),marginal (n = 6), or right coronaryartery (n = 5) were found. A combinationof PTCA and thrombolytic treatment (ineight patients extended thrombolysis for24 hours) was successful in reopening thevenous graft in 16/21 patients (76.2%).Immediate complications included fem-oral haematoma (4), distal embolisation(3), and infection in one patient. Out of13 patients catheterised within threemonths, two had reoccluded, seven hadrestenosis, while four had patent grafts.Recurrent PTCA (at least once more)was done in eight patients. At long termfollow up of a mean of 26-7 (21.6) months(range 4-75 months), four patients were

asymptomatic, eight still suffered frommild stable angina, while three hadrecurrent hospital admissions andneeded a second coronary artery bypass.A combination of thrombolytic treatmentand PTCA is a feasible and practisedapproach to recanalise recently occludedvenous bypass grafts.

(Br Heart 1994;74:455-459)

Keywords: percutaneous transluminal coronary angio-plasty; thrombolytic treatment; coronary artery bypass;venous bypass graft occlusion

Late occlusion of coronary artery bypassgrafts usually presents as new or worseningangina pectoris and often as acute myocardialinfarction. In most patients, the occludedgraft is filled with thrombotic material so thatconventional thrombolysis is relatively ineffec-tive in restoring good flow in the graft.' 2

Conventional percutaneous transluminalcoronary angioplasty (PTCA) also has a lowsuccess rate and may result in extensive distalembolisation.3 4 This study will examine thepotential of using a combination of mechani-cal and thrombolytic treatment for totallyoccluded bypass grafts.

MethodsBetween 1987 and 1992, 3416 PTCA proce-dures were performed at the HadassahUniversity Hospital catheterisation laboratory,of which 125 (3.7%) were performed oncoronary venous bypass grafts. In 21 of thesepatients (16-8%) the venous bypass graft wasfound to be totally occluded at the time ofangiography, but the occlusion was judged tobe recent on the basis of clinical information(recent onset of symptoms) and angiographicfindings (defined deep niche > 1 cm and/orstaining of a thrombus in the graft). Thereforein these cases a combination of PTCA andintragraft thrombolysis was attempted toreopen the occluded graft. In 13 patients,repeat angiogram was performed between twoand six months after initial PTCA to deter-mine the long term results.

All cineangiograms were reviewed by twoobservers to determine the distance from graftorifice to occlusion, the pattern of retrogradefilling of the culprit artery, the existence ofthrombotic material, and the primary andlong term success.

PTCA PROCEDUREIn all patients, an initial attempt was made topass a PTCA guiding wire through the graftinto the distal coronary artery. This was donein order to assess the freshness of the throm-bus and to facilitate delivery of thrombolyticsinto the graft. This was followed by slowintragraft infusion of urokinase (a dose rang-ing from 500 000 to 1-5 million) or streptoki-nase at a dose of 750 000 units. After 30-60minutes an attempt was made to pass a 1-5mm balloon catheter through the graft with

455

on April 15, 2021 by guest. P

rotected by copyright.http://heart.bm

j.com/

Br H

eart J: first published as 10.1136/hrt.74.4.455 on 1 October 1995. D

ownloaded from

http://heart.bmj.com/

Lotan, Mosseri, Rozenman, Hasin, Gotsman

recurrent dilatation distally to facilitate thedelivery of thrombolytics into the thrombus.Improvement in recanalisation was assessedby repeated injection of contrast material asthe balloon was advanced distally. In patientsin whom an open channel was achieved anddistal flow in the native coronary arteryobserved, a balloon with a larger diameterwas used to dilate the stenotic segment simul-taneously with the continuous infusion of thethrombolytic agent. In patients who had alarge thrombotic mass, a guiding or diagnos-tic catheter was left in the graft orifice andcontinuous urokinase at a rate of 100 000units/hour was delivered into the graftthrough an infusion pump for a further 24hours, the procedure being completed the fol-lowing day.

All patients were maintained on intra-venous heparin (to keep their partial throm-boplastin time at twice normal) for 3-5 days,overlapping with adequate oral anticoagulanttherapy. In addition, the patients receivedaspirin, nitrates, and calcium channel block-ers.

Values are given as mean (SD).

ResultsPATIENT CHARACTERISTICSTwenty one patients were included in thestudy: 20 (95%) were males and the meanage was 64-5 (5 6) years. The mean timeinterval from coronary artery bypass graftingto the current catheterisation was 8-02 (4'02)years (range 1-13 years). The mean numberof bypass grafts was 2-28 (1-02) grafts perpatient.The presenting symptoms were crescendo

or unstable angina pectoris in 19 patients andmyocardial infarction in two. The mean timefrom onset of symptoms to catheterisationwas 21-7 (18-6) days with a range of 1-60days. None of the patients received throm-bolytic treatment before coronary catheterisa-tion.

ANGIOGRAPHIC FINDINGS AND PTCA RESULTSOut of a total of 49 venous bypass grafts inthe entire group, only 12 grafts (24 4%) werestill patent at the time of angiography. In 21of the 37 occluded grafts, the occlusion wasjudged to be recent.The culprit occluded venous graft supplied

the left anterior descending coronary artery ora diagonal branch in 10 patients, the first orsecond marginal artery in six patients, and thedistal right coronary artery in five patients. In15 patients (71%) a well defined niche (> 1

cm in length) from graft orifice to occlusionwas observed. In 20 of the vein grafts, thethrombus was extensive (> 3 cm in length)and filled the entire graft.

Interestingly, in only five of the patientscould flow in the native coronary artery sup-plied by the occluded grafts be seen. In threepatients poor anterograde flow was seen withdiffuse severe proximal disease, while in twoothers marginal and posterior descendingcoronary arteries were retrogradely filled

through a distal left anterior descendingartery.The combined strategy restored flow in 16

of the 21 patients (76%). In two patients, thePTCA wire could not be passed through thegraft and thrombolysis did not restore flow.In three other patients, the PTCA guide wirecould be passed through the graft but thethrombotic mass was very large, and an openchannel could not be achieved despite pro-longed (up to 24 hours) thrombolytic ther-apy. The mean time from coronary arterybypass graft in these five patients (7 7 (2 8)years) was not different from the entire group(8-02 (4 02) years). However, the time fromsymptom onset to coronary catheterisation inthese five patients was 41 (22) days comparedto 14-3 (15) days for the remaining patients.Of the five patients in whom visible run offcould be seen in the native coronary arteries,revascularisation was successful in only two.

In most patients (13 of 16 successfullyopened grafts) signs of residual thrombuswere noted (hazy areas, small filling defects,and irregular luminal surface) and thusheparin treatment was continued in allpatients for at least 72 hours, overlapping andcontinuing with oral anticoagulant therapy.

Procedural complications occurred in 11patients (table 1). One patient developed ven-tricular fibrillation during infusion of uroki-nase to a proximally occluded left anteriordescending coronary artery graft, and intra-aortic balloon pump support was needed.This patient subsequently developed acuteanterior myocardial infarction. Three otherpatients had a rise in creatine kinase to 321(192) units without significant changes on theelectrocardiogram (for example, new Qwaves), probably reflecting distal embolisa-tion. Four patients had a large femoralhaematoma and needed blood transfusion,and three patients with prolonged throm-bolytic therapy developed fever and chillsrequiring antibiotic treatment.

Short term results are listed in table 2. Ofthe 16 patients with successful procedures, 13(81%) were catheterised within two to fourmonths after PTCA. In four patients, thegraft was patent, in seven graft restenosisoccurred, while in two the graft reoccluded.Eight of these patients had one or morePTCA attempts.At long term follow up (mean 26-7 (21-6),

range 4-75 months), six patients were free ofangina, eight had mild angina (grades I or IIaccording to Canadian CardiovascularSociety function classification), while threehad recurrent hospital admissions and under-went a second coronary artery bypass graft.The figure shows sequential saphenous

vein graft angiograms from a patient with anoccluded graft to the right coronary artery.

DiscussionRecent studies have shown that symptomaticlate graft occlusion is caused by thromboticocclusion with a pathological process that issimilar to native coronary artery occlusion.'-3

Table 1 Complicationsafter PTCA to graft

CardiacMyocardial infarction+ ventricular fibrillation 1CK increase 3

GeneralFemoral haematoma 4Fever, infection 3

CK, creatine kinase.

Table 2 Short termresults after successfulPTCA (n = 13)

Patent grafts 4Restenosis 7Reocclusion 2

456



j.com/

Br H


ownloaded from


Combined mechanical and thrombolytic treatmentfor totally occluded byass grafts

Sequential saphenous veingraft angiograms frompatients with an occludedgraft to the right coronaryartery. (A) A 10 mmniche of the occluded graftto the right coronary artery(arrow; left anterioroblique view). (B) A hightorque floppy guiding wirethrough the graft into thedistal right coronaryartery. (C) Injection ofcontrast during urokinaseinfusion. Partialfilling ofthe graft with staining(arrow) compatible with alarge thrombotic mass. (D)24 hours after continuousurokinase infusion. Thereis still haziness and stenoticsegments of the grafts. (E)Inflation ofa long balloon(40 mm length) in thegraft. (F) Finalappearance of the graftwith goodflow to the distalartery .

A

000-..~

B

D

E

i:

The absence of side branches and distal runoff in the graft leads to stagnation of bloodwith rapid proximal propagation of thethrombus, forming a large thrombotic mass.This explains the relatively low success ofconventional intravenous thrombolysis inrestoring coronary flow. Similarly, conven-tional balloon techniques were found to beinadequate to deal with the large mass of

thrombotic material, and the danger of distalembolisation was very high.2 Thus an attemptto combine both mechanical and intragraftthrombolysis may be more successful inrestoring coronary blood flow. Indeed, usingthis approach, a relatively high initial successrate (76-2%) for restoring graft patency wasachieved, similar to the findings reported byHartmann et al.4

457



j.com/

Br H


ownloaded from


Lotan, Mosseti, Rozenman, Hasin, Gotsman

In our experience the most important indi-cator of procedural success was the time lapsefrom graft occlusion to PTCA. The fivepatients with unsuccessful recanalisation hada longer duration between symptom onsetand PTCA. Angiographically, recent occlu-sions were characterised by a deep niche(more than 1 cm from graft orifice), ability topass a PTCA guide wire, and the existence ofrecent thrombi observed as circular lesions orfilling defects with persistent contrast stain-ing.

Interestingly, visible run off in the nativecoronary arteries supplied by occluded graftswas only seen in five patients. It might be thata short time after graft occlusion collateralflow is still lacking. Thus a visible retrogradefilling of the native coronary arteries may sug-gest a more chronic process. Alternatively, itmight be that patients with good retrogradefilling of the coronaries may have "silent"occlusion of their grafts, while "symptomatic"graft occlusion suggests that the flow in thecoronary artery (either antegrade or retro-grade) is not sufficient.

Extended intragraft delivery of throm-bolytic agents has been shown to improvereperfusion success.5-7 The use of special per-fusion wires or perfusion catheters such as theTracker catheter that can be placed deep inthe thrombus has enabled improved deliveryof thrombolytic agents with better resolutionof thrombus.'8 Nevertheless, in most casesresidual stenosis and thrombus still exist.Thus a prolonged infusion of intravenousheparin with overlapping to oral anticoagu-lants for several months is essential in allcases where successful reperfusion of anoccluded graft was achieved.

Despite the fact that the overall short termrestenosis/reocclusion rates found in thisstudy were relatively high, they are not signifi-cantly different from restenosis rates inpatients undergoing PTCA in the shaft of asaphenous bypass graft. However, since inmost of these cases only restenosis occurred,successful repeat PTCA was achieved in eightpatients (87%). Long term results showedthat the majority of patients had either mini-mal or no angina at all, while only threerequired a second coronary artery bypass.The morbidity involved in this combined

approach is not negligible, since one of ourpatients sustained a Q wave myocardialinfarction and three others showed somedegree of myocardial damage sufficient tocause a rise in creatine kinase values.Moreover, this procedure involves leaving thecatheter within the occluded graft for a rela-tively prolonged period of thrombolysis treat-ment, thus increasing the risk of infection.Indeed, signs of infection and femoralhaematomas were seen in 14A2% and 19% ofthe patients respectively.

Therefore a search for new devices that canachieve better removal of the thromboticmaterial must continue. One of these devicesis the transluminal extraction atherectomy(TEC)9 which has been specifically recom-mended for dealing with degenerated saphe-

nous vein grafts.'0 The TEC, however, isavailable only to a limited number of centresthroughout the world. Another device that ispresently under investigation is the "hydrol-yser" which is designed as a hydrodynamicthrombectomy catheter to deal especially withlarge thrombotic masses in old diseasedsaphenous vein grafts."

STUDY LIMITATIONSThis study was derived from a retrospectivecohort of patients that had a combined intra-graft thrombolysis and PTCA for totallyoccluded bypass grafts. Since no uniformapproach to thrombolysis was used, the doseand length of intragraft thrombolytic treat-ment varied, and were dependent primarilyupon operation assessment of thromboticmass, as well as on the initial degree ofthrombus resolution in the catheter labora-tory. Only in the last five patients was adefined protocol of extended intragraftthrombolysis and PTCA used.

CLINICAL IMPLICATIONSLate occlusion of saphenous vein grafts isusually the result of acute thrombotic occlu-sion of underlying fibrotic and atheroscleroticchanges in the body of the graft as well asprogression of arteriosclerosis in the graftedvessels. Since these patients usually sufferfrom coronary artery disease for many years,most may develop some degree of collateralflow as well as progression of arteriosclerosisin the grafted vessels. Thus most patientswith graft occlusion may experience only mildchanges in the anginal syndrome and only afew develop myocardial infarction. Thereforepatients after coronary bypass grafts whoexperience significant changes in their anginalprofile should be referred for early angiogra-phy. If recent occlusion of the venous bypassgraft is suspected, a combined mechanicaland thrombolytic approach should be consid-ered. On the basis of the exact angiographicfindings in each patient, the risk of the proce-dure should be weighed against the benefitthat early reperfusion of the occluded graftmay prevent or delay the need for anothercoronary artery bypass graft.

We thank Chava-Ita Kaniel for helping in data collection andpreparation of the manuscript and Shoshanna Weinstein forsecretarial assistance.

1 Grines CL, Booth DC, Nissen SE, Gurley JC, BennettKA, O'Connor WN, et al. Mechanism of acute myocar-dial infarction in patients with prior coronary arterybypass grafting and therapeutic implications. Am JCardiol 1990;65:1292-6.

2 Sabri MN, Johnson D, Warner M, Cowley MJ.Intracoronary thrombolysis followed by directionalatherectomy: a combined approach for thrombotic veingraft lesions considered unsuitable for angioplasty.Cathet Cardiovasc Diagn 1992;26:15-8.

3 Bell C, Kern MJ, Kaiser G. Sequential proximal and distalinfusion of urokinase resulting in recanalization ofacutely occluded aortocoronary bypass graft after coro-nary angioplasty. Cathet Cardiovasc Diagn 1992;26:224-8.

4 Hartmann JR, McKeever LS, Stamato NJ, Bufalino VJ,Marek JC, Brown AS, et al. Recanalization of chroni-cally occluded aortocoronary saphenous vein bypassgrafts by extended infusion of urokinase: initial resultsand short term clinical follow up. J Am Coil Cardiol1991;18:1517-23.

458



j.com/

Br H


ownloaded from


Combined mechanical and thrombolytic treatmentfor totally occluded byass grafts

5 Mosseri M, Hasin Y, Admon D, Gotsman MS.Thrombolytic therapy of a stenosed coronary veinbypass graft with continuous intragraft streptokinasedrip. Cardiology 1990;77:318-21.

6 Chapekis AT, George BS, Candela RJ. Rapid thrombusdissolution by continuous infusion of urokinase throughan intracoronary perfusion wire prior to and followingPTCA: results in native coronaries and patent saphe-nous vein grafts. Cathet Cardiovasc Diagn 1991;23:89-92.

7 Doorey AJ, Rosenbloom MA, Zolnick MR. Successfulangioplasty of a chronically occluded saphenous veingraft using a prolonged urokinase infusion from thebrachial route. Cathet Cardiovasc Diagn 1991;23:127-9.

8 Hibbard MD, Holmes DR. The Tracker catheter: a newvascular access system. Cathet Cardiovasc Diagn 1992;27:309-16.

9 Popma JJ, Leon MB, Mintz OS, Kent KM, Satter LF,Oarraind TJ, et al. Results of coronary angioplasty usingthe transluminal extraction catheter. Am Cardiol1992;70: 1526-632.

10 Sketch MH, Labinaz M, Stack S. Extraction atherectomy.In: Topol A. Textbook ofinterventional cardiology, 2nd ed.Philadelphia: WB Saunders, 1994:668-77.

11 Fajadet J, Diaz L, Cassagneau B, Robert G, Bar 0, MarcoJ. The hydrodynamic thrombectomy catheter: prelimi-nary experience in human old saphenous vein grafts[abstr]. Circulation 1993;88:I-64.

459



j.com/

Br H


ownloaded from


treatment - heart · totally occluded venous grafts are usu-allyless...

Documents