CHAPTER 34 Angioscopically Assisted

CHAPTER 34
Angioscopically Assisted
Thromboembolectomy
Thomas J. Fogarty, Christopher K. Zarins,
Kenneth L. Serra, Christine E. Newman,
and George D. Hermann
lnrrod uced In 19fi3, the balloon em bolectomy carhertr
hal> proved to be ~ n im po rranc contribution fO rhe
deveJopmt"nt of endovascular devices to assIst in the
treatm en t of peripheral vascular ocdusi~e disease (l,2).
Ie has a l~o provided a template for the deslgn of orher,
more speuabzed c<l(hner tools to address the remova l
of the resid ual thrombus associmed with incom plcre
throm boem bolectomy. Before the adven r of balloon
em bolectomy Cllti)e(Cr techniq ue, !>urgicaJ prncedures
for removJIlg thrombus were tnwghr with co mplica­
tions that resulted in high patient mortality :md 1110(­
hid it)'. USIng the em bolectom y catheter to remove ac ute
peripheral emboli has impro\'ed surgical outcome and
conseq uently patiem survival. Independent studies con ­
ducted by Tawes er a l. (3), Ellior ct al. (4 ), Abbott e( al.
L5), and Camhria an d Ahbott (6) have shown limb sa l­
vage ra tes of 85% to 95% with a ttendant !l1 ortil lity
cares reduced to '10% to 20<>1<>
Going beyond [he basic em boltcromy pro(;edure,
new catbeter-based technologIes, developed from a m()r~
lIl-depth knmvledge and understa nding of (he niology of
tht, va,cular occlusive d isease process, have em erg.:d to
addrc)) the variou~ progressive 5law:s of disease. In so
doing, the less invasive, endovascubr field has evolved to
indude man)' n~w moda hties WhO:il' primary applicmion
is not to physically remove th rom boem bolic m ateria l but
to pr()\'ide assistance in 1) diagnosis, 2 ) facil itation of the
therapemie endovascu la r su rgical proa d ure, a nd 3)
postoperative eva luation of rhe resultanf efficacy of [he
surgical intervention. These modalities include a ngllr
scopy [hat allo\vs a 3600 endoscopic VIsualization of ves­
sel lumen, and th e more n:ccntlr introduced intral uminal
Doppler ultrasonic imaging, which provides an echo
im<1ge of rhe inrima and su rround ing li ~s u e structures.
The followmg w ill describe applications suited to
a nglOscnpy and will specifically address the adva ntage~
and disadvantages associated with the llse of angioscopy
\tl thromboembol ectomy.
Angioscopy
Angioscopy m ay be defined simply as the end oscopic
impccrioll of the lllrcrior of a blood vessel (7). Con­
stra ined by the ina ppropriately sized instrumen ra tion
~\'a i lab l e ar [he till1\:: and the diffic ulties with ligh t rmns­
m iss io n, the ea rliest atte mpt~ at endoscopic vlsualiza­
tiOll o f blood vessels had limited Sllccess. Early ellcio­
~cope s were large and infle xible and offered POOf
visualiz.·uio n in an opaque visual fi eld. Ovc:r the past 20
y~ars rhe development of ~ malle r, tlexible, and maneuver­
able endoscopc.s, videocamera technology, ~nd improved
445
446
Part V Occlusive Arterial Diseases
irrig::ttion management has allowed surgeons to more
accurately visualize the intraluminal field.
Angioscopy experienced increased usage within the
vascular surgery specialty after the benefits of using
laparoscope~ within the general surgery field were
documented (8). Currently, angioscopic instrumentation
not only offers valuable diagnostic capability but also
may bc used adjunctivdy with other endovascular thera­
peutic devices. Angioscopy is used as a method of "con­
trolled guidance" to aid visualization within vessels when
patients undergo procedures such as thromboembolec­
tomy, atherectomy, artenovenom fistula graft revision, in
situ bypass, venous valvulotomy, and stent deployment.
Potential diagnostic applications for angioscopy
have been extensively described in the literature (9-11).
They mclude, but arc not limit ed to, the following:
1. intraluminal evaluation of traumatic arterial
lllJury
2. in vessel occlusion, defining the character and
consistency of plaque, 'whether it is thromboti('
or atheromatous
3. direct correlation of angiographic findings
4. diagnosing pulmonary embolism
5. assessing the integrity of vascular reconstruc­
nons
6. directly interrogating veins for bypass suitability
7. localizing discrete venous valves and branches
III vein preparation for 1Il situ bypass
8. evaluating coronary arteries
9. evaluation and location of l11ultifocal lesions
to choose a therapeutic modality
10. detection of potentially significant intimal flaps
and thrombi undetectable by Doppler ultrasolllc
exammatlon
11. providing an alternat ive to angiographic assess­
ment of reconstructions and detection of vessel
abnormalities
As a monitorillg tool, angloscopy is used in the treat­
ment of vascular disease, to provide dir~ct visualization
during or afrer the following intcrvcnrional procedures:
1. ll1fusion therapy (i.e., thrombolytic, vasodilator
treatment)
1. thromboembolectOmy
3. balloon dilatation or angioplasty
4. atherecromy
5. endarterectomy
6. valvulotomy
7. vein branch ligation
Proper angioscopic evaluation has been shown to
affect the duration of a patient's hospitahzation (12)
and has been shown to be a safe, SImple, effective alter­
native or adjunctive procedure to intraoperative angio­
graphy (13). To better appreciate the application of
angioscopy assistance in thromboembolectomy, the
basic anglOscoplC system components and functionality
should be understood.
Angioscopic Instrumentation
Angioscope
The viewing tip of the angioscope is shown III Figure
34.1. It consists of a flexible catheter comprising one or
two fiberoptic light bundles, a fiberoptic image bundle,
and a working channel that is frequently used as an irri­
gation port or to introduce guidewires or other intra­
vascular tools. Currently anglOscopes come in lengths of
20 to lOa em with distal tips ranging III diameter from
0.6 to 7 mm. The degree of variation 1Il angioscope
components is directly related to the diameter of the
catheter. In smaller-diameter anglOscopes, fewer fiberop­
tic fibers can be accommodated, necessitating exclusion
of the working channel in many lllstances. As stronger,
more inrense light sources become available, it may be
possible to decrease the light bundlts from tWO to one,
thus allowing room to accommodate the important
working channel in all angioscopes.
Fiberoptic bundlts can either be drum wound
(leached hundles), consisting of individual fibers bound
at the ends, or three glas~ (fused bundles), which allows
the scope size to be reduced by fUSIng individual fibers
into one cohesive strand. The drum wound angioscopes
are nondisposable owning to their high cost, while the
fused bundle units are less expenSIve and disposable.
The angioscope is steered by passive guidance, tracking
with a guidewirc:, or activating tip deflection manually
with a control button on the angioscope handl e. More
advanced deSIgns have incorporated an operator­
controlled deflecting tip allowing greater maneuver"
ability of the angioscope within the vessel. This feature
gIves the surgeon the ability to guide the anglOscope
into the appropnate vessel conduit when encounrerlllg
bifurcations or to more easily visualize branches or
tributaries. Two-way deflecting systems will allow 45°
deflection In one direction and up to 90" deflection in
the oppo~ite direction for a more complete endolumi­
nal interrogation. The flexibility of these soft deflecting
tips reduces the potential for intimal damage.
The proximal end of the catheter is attached
directly t o the angioscope. The angioscope usually sup­
ports an Irngatiun port, an attachment to the light
source, and an attachment to a miniature camera. This
camera acts a~ a small telescope outputting to an obser­
vation site, which may be the viewer's eye, or through a
standard videocassette recorder to a high-resolution
monitor. The video display provides real-time visual
feedback during the p[(Ju:durc and a vid eo record of the
Intervention for later use and procedure documentation.
Camera System
The camera system on an anglO~cope converts the
image picked up at the proximal end of the ~cope, pro­
jected via the fiberoptic bundles, mto a digital Image
that is transmitted to the eyepiece or the display on the
vJdeo monitor. A fe"v manufacturns mdude a camera
Cllilpl.:r 34 Aogiosoopic:ally Assisled T hromboembolectomy
~y~ te m as part of the total angioscope system, h ut as
most operating woms have several camera systems uti­
lized by ath t,'r ')pecia lties, adapters may be acqu ired to
allo w imerface of the a ngioscope ro these existing
devices. T his t ime-sha ring of ea me ra ~ from one depart­
ment to anmher can decreJ.se COS tS considerably, which
may he especia ll y Important to fi nancially co nstrained
institutions.
Ano ther integra l co mponCIH to the camera system
is (he ca mera coupler. which magnifies [he t ra nsmined
image up to 20 ti me; it s orig inal size. It a llows 3600
rotation and suppons the focu si ng ring for image qual­
ity adjustment. This is a reusa ble component, which
o nce aga in provid es a fina nci<1l saving when mcd with
d isposable angioscopcs.
Light Source
Another imponant part of thl.' angioscope system is a
focused light so urce. Typica ll y angimcopic illum ination
is p roduced with xenon, the whitest and mo~t efficient
light sou rce, emitting a range o f between 75 a nd 300 W
of power. Ligh( ompm fr om the angioscopc tip is tyPI­
ca lly 2 to 20 mW/(:m 2. Quartz halogen light so urces of
150 W genera lly do not pr~)V i de adequlte lig hting
because they are le,>~ d ficient. HOEll a re cold light so u rces
FIGURE 34.1 Angloscope
System: !A) flberoptfc visual
bundles, (8) Irrigation lum en,
(e) fiberoptic light bundles.
(0) angioscoO€ catheter. IE) Irriga­
tion port, (Fj 119ht source CO UPler
to angioscope. (G) chip -cam era,
44 7
t() avoid heating the del icate fi heroptic bundles. The light
sources are equipped with different brightness settings
that are indicated by a visual display, generally (l light­
em irring d iod e bar-graph or liqu id ctystal d isplay read­
o ut. Some angioscopic systems also ma y co nta in a filter
wheel that provides options for correction w hen
P()laroid or indoor film is used during the procedure (7).
The :mgioscope is connected via a fibero ptic light cord to
the light source. T he light cord properly aligns the light
sou rce with (he fi heroptic bundll.'s to a cll1(~ v~ a d ~qua te
tndov:Jscular illumination. Most newer systems a uto­
maric<ltiy adjust the light source in re~p ()nse to the
reflected li ght to preserve image integrity.
The ang ioscope operatOr mu st become fully famil ­
iarized with the vario us light source modal ities to
o bta in maxim u m d ispla y q ua lity. As a n exam ple, flex­
ib le anglOscopes used in the endovascular sen ing
requ ire more light than rigid rod-lens sco pe ~ freqllently
used in arth r()~copic and uro logic evaluations (14 ).
Conversel y, in ~ maller vessels, less lig ht lntensi t ~· is
req uired for a good image; I.'xcessive light can p roduce
n whi re o r blanc hed image. Pro per manipula tion of
light intemity c::ln sign ificantly n:duce the time take n m
complete a procedure and therehy improve image dis­
play quality and decrease the possib ility of mlSl nter­
p recing or entirely overlook ll1g pertinen t pachology.
J
(HI camera controi llnit , fIl video­
cassette recorder, U) video
monitor, (Klll gh t so urce.
F
E
A
c
8
44 8
Pari V Ocdusi\'e Arlerial Disuses
Video Monitor
A high-resolution color video monitor IS :In indispcm­
aoll": pan of an ilngioscope system. This tct:hnologr
emerged from the gasr rointestin.11 endoscopIc sysrem
rhar dcmon.Mrared the supl":riorit y o f di rect videoendos­
copy. Early angioscope designs incorporated eyeplecc~
simi lar to :l urologist's cystOscope for di rec( visualiza­
(ion o f the intralu minal sp<1ce. This vi<,ualiz::uion tech­
nique pto... ed cu mbersome for (he ... ascula r surgeon
who is often required to move abou t within the sterile
operating fiel d or change position during an operation.
The video moniror alleviates these mobility mmt rainrs
and provides the opportunity for rhe entire surgical
team to monimr the proced ure. In most modern oper­
ating rooms, angioscopic mon itonng is ... iewed on a
wlor video display.
The video monitor display is cspecil il y useful as a
tool to assist in traini ng d inicians in angioscopic tech·
nique. The :l ngioscopic image is displayed as a small
bright circle on rhe ... ideo monitor. Newer systems
allow digirizaTion of rh ~ image to fill the entire screen
for easier viewing. A high-quality monitor cap:lble of
displaying crisp, dean color images wiU enable prec ise
differenti;ttion of endoluminal d isease characterinics.
As in the previous discus:.ion of lighT source coupling,
proper conne<: fi on of el ml'ra clements to video display
is critical to clear ... iSUll iz:::niun.
Irrigation System
Irriga tion systems are critical to an angioscopy system,
ye t arc one of th e mt"l~t overlooked component~. T ht
vascular SYlu::m, nnli ke the gas! roimes tin ai, uro logic,
or arthroscopic fields, po~es a unique challenge in that
its visual .field is obscured by pllJs<ltile. ~w i rling, opaque
blood. As "nooILimi nal angioscopic fechnology ha'i
been borrow~d from th~se other endoscopic modalities,
the irrigalio n :.ystcms successfull y used in genera l
surgery ha ... e pro ...ed to b~ inappropria te for endm'as­
cular applications. O...ercoming this obsracle hy fi nding
bem' r ways to cl imin:He baekfl ow and displace blood
from the visual fid d is still an .uea of devc:1upment.
Recogniz ing th e s t rcngth~ and limitations of cu rrent
irrigation systcms will impro ... e the video image and
minimize complicat ions associated with nUld ovcrload .
Currentl}', three types o f irrig.1tion system are availahle
(0 tht' vascula r surgeon. (Fig. 34.21.
T he b<'lsic irrigalion s),s(em consists of a sali ne bag
with a line directly artached to (he irrigation port on
the angioscopc (Fig. 34.2A ). T he irrigating ~{J l u t ion
bag, when suspended on :1 pole used fo r intra"~nous
drip, provide~ a source of co nstant p a~s i ... e pr('ssure
tha t clears the visual intraluminal field. Alternatively,
,)!1 as,mant mar sq ueeze the bag, either h~' hand or
with a blood pressure cuff placed around thl": bag,
while pinching off the direct li ne TO pro... ide ... arying
amounts of pressure as deemed appropriare to clear the
o
A
B
o
c
Pinch Valve
FIGURE 34.2 VariOUS angloscope irrlga! iOn syst ems:
fA} simple saline bag irrigation syst em . f81 peristaltic
foot ·activated pump, fe) foot -activated pressure
vessel pum p.
field. The disadvantages of this somewha t cumbetsome
tn.:hnique are tw()fold: monitori ng the amount of fl uid
infused into the ... e~sel often can he unreliable, and il is
difficu h to ~\ ccunltely regu late the Auid pres~ure. This
initial approach has been la rgely abandoned.
A moce advanced infusion irrig:aion systt'm is the
roller pu mp IFig. 34.2B). T his sySTem is more sophi~tj.
cated than the passive pressure sa line bag setup in that
a roller pump activated by a foot switch crc ate~ a pe rl·
staltic infusion of sa line, eliminating rhe need tn coor­
dinate sa li ne infusion will'l an assistant. Furthermore,
rhe flow rafe ca n be preset co a desired level, emin ing
from 10 TO 400 Ill i per minure from the angioscopt:' rip,
and rhe volume of infused fl uid can be continuallv
monitored aurom3tiC<1Ily. A fairly high pressure level i~
required ro rransmit Il uid down the sma ll-diameter
angioscopic work ins clulOnel over :I distance of up to
100 em. T he period of high-pressure infusion is tempo­
rary and gener311y not of great concern, but should be
considered when operat ing within a dosed s~rs re m.
The !'ollc:r pump, although \t provides ~~veral au to·
mared fcatu res, i~ nOt without drawbacks . When the
foot SWi t ch is initially 3.ni....1ted, sali ne is infused at a
Chapter 34 Angioscopically Assisted Thromboembolectomy
low pressure unt il the roller pump build s up to rh e
de:.:ired set speed. T his shorr period o f low-pressure
infusion is insufficienr to displa<:e blood and dea r the
visual held, yet some volume of saline h ~l S been <ldded
to the patient's vascu lar system, rncreasing fl uid load
whil e fading to maxllm ze the rime spent visu ally inter­
rogating the vessel. Also, beca u~e t he pump IS not
responsive to flu id bui ldup an d p re~ sure feedback, ves­
sels infused wirh in a closed system (i.e., disnl Jlr
cla mped vessels wi th occluded side branches) lIlay
undergo a dramatic increase in intra-arterial pressure
that has the potential to damage the ve~sel waJl among
othel" vascu lar complicatimls. Curre ntly, rherc is no
effective m ea n~ to com pensate fo the potential pre~s ur e
buildup u~ ing the roller pumps because (h ey are not
pressurl;' $ensitive . Conseq uendy, care should be taken
to monitor fluid ind ucrion with rhis system.
T he rhird irriga rion system combines the :-.d va n­
t.1ges of the two previously dc ~cribed systems (Fig.
34.2C). The release of irrigatio n fluid (contai ned in a
,ali ne-filled bag housed within a press ure vessel) is con­
trolled by pressure changes initiated when an onJo ff
foot )witch is activitcd. A bolus of flui d in rhe range of
250 to 350 ml per minUTe may be infused to quickly
clear the visual field when baddlow is encou ntered,
wh ile 10w~llo\\' infusion at 60 ro 80 ml per minute is
us ually adequate to maintai n a constant, unobstructed
field of view. In addition to having an external pressure
regul ator, this irrigation system is pressure ciependenr,
th athy OVerC0l11111g the problems assoClated wi th inrra­
arten,,1 pressure buildu p and minlllllzmg the ri sk of
flui d oved oad . Usually, 2.'1 to 30 psi IS sufficient (Q pro­
cure a d e::ar visual field in the ileofemoral system and
below (14) . A pinch vah'e ensures that the ini tial infu­
StOll () f saline will he ma im"i ned at the preset pressu re,
thereby providing rapid clearing of the visual fi eld and
saving procedure time and 1Il1IleCessary fluid ad tn imstra­
non. Tot al infused volume, ~ h o uld be carefully moni­
(Ored co pre.. . ent patient fl uid o\'erload . O fte n newer
Ifrigation systems have heen designed with an auto­
matic shut-off fea ture as a ~afety mechanism in tracki ng
tluid infus ion to alen [he dinician to fl uid ad m i n iH ra~
[I on volumes before reac ht ng a lOOO-ml mfusion level.
operative setup
Optimal utilization of rhe angioscopc in surgery requ ires
.:omplete familiarity with the equ ipmenr and its appro­
priate loca tion relative to the sterile .~ lIfgica l fi eld. T he
ltlstrumenratlOl1, includ ing the chip-videocamera, ca m­
era coup ler, light source, videocassette recorder, video
d l ~p l ay mOllitOr, and irrigation pump, shou ld be
mounted on a mobile cart (lpposite the surgeon. Dupli­
cate display monitors may he mounted at OI.her st ra tegic
locations for easy visualiz.atiOIl of rhe procedu re hy the
other members of the su rgical ream as appropriate.
T he ste rile angioscope is placed on a separate ta ble
so that prepa ration for angioscopy can be made with­
449
out distllrbit:lg the surgical p reparation of the operati ve
site. PI'eopenaive preparations should include connec­
t ion of the camera to the light source, focusi ng the
angioscope, and white-balancing the light for proper
co lor before using the mstrumentation in the case. T he
angioscope, its co nnecting cable, :.lnd irrigation tubing
are brought around th e an gl0~c('"1p i s t and secured to the
drapes over the chest of rhe patient (15).
Operative Considerations for Angioscopy­
Assisted Thromboembolectomy
A st:tndard meth od of angioscopic exam mation shou ld
be developed for each angioscopic apphc3.tioll and
~houl d be varied according to the operative procedure
and th e nature of the region of inte rest. M ill er
describes :':Llcil procedures in his recent work. "Angio­
scopy: Itlrroducrion and B<lsic Techniq ues," wh icn tne
intervenriona list may find useful as a template for ind i­
vidualizing operative prOTOcols ( 16) . When using
angioscopy w assist during throm boembolectomy,
choosing the proper size <l T1 gioscope IS of paramount
importan<.::e. The diamete r of the angioscope shou ld be
the largest that can be easily introd uced into the vem:1
giving due considera rion to lumi nal tapering as rhe
cathete r is advanced. Carefu l angioscope selection will
min imize visualization difficulties such as dark or
hlanc hed images and reduce tl,e danger of ind ucing
spasm in a native artery.
New Thrombectomy Devices
A grea ter understandmg of the pathology of peripheral
vascular disease was brought about, in parr, by
improved vis ualiza tion modali ties . This, in rur n, ha~
prompted the development of new thrombeCTOmy
devices designed to address the various stages of ath ero­
~ler otic disease. Two ~u c h rools ha ve recently been
added to the surgeon's endovascular instrumentation
arnU ment.llrium. Both the co'rkscrew-shaped adherenr
clot catheter and the ope n ~\V i re graft thromhectomy
catheter (Baxter Healthcare Corp., Vascular Division,
Irvine, C lli!.) are deSigned to more complete ly remove
adherent throm botic material after embol ectomy, and
their benefi cial dfects cnn be easily docum ented when
t h~y :He used in conj unoioll with angioscopy.
Adherent Clot Catheter
Figure 34.3 is a drawing showing rhe longitudinally col­
l ap,~ed insertion position of the adherent clot c.atheter
ti p. The device comim of a tlexible catheter with a dis­
tallarex-covered coiled cable at its tip. A rhu!1:1 b-ilcti­
vated lever on the instrument hnndle allows the surgeon
to adjust rhe pi tch of the co rkscrew membrJ.ne from
a fully collapsed, sm an~d ia me ter position, to a tightly
spiraled retracted con ligu ration with a diameter of
up to 10 mm (14). By advancing the catheter in the
4 50
Part V Occlusive Am:rial Disease!>
low-profi le, collapsed position, then expanding it to its
wider-diameter con figuration, adherenr thrombus is
"grasped " by the closing spi r.1l loops of the corkscrew
membrane (Fig. 34.4 ). In the sa me fam iliar manner an
em bolectom ), procedure is perfo rmed, the adheren t clot
catheter is withd rawn in its expanded posi tion toward
the aneriotomy, and the clot is removed man ually. The
pitch of the rerr iev3 1 element may be adjusted b)' the
thumb lever if resistance is encounterl': d during the
withdrawa l process ( 0 ad i u~ t the gripping force during
withdrawa l.
A
;.f {
"
B
Graft Thrombectomy catheter
The distal working eil': mem of thl': graft thrombectomy
ca th ecer is designed much rhe same as the adherem dot
catheter (Fig. 34 .5). Both use the principle of a hand ­
operated, expandab le, variable-pitch coil to grasp and
remove adherent thrombus. However, two features dif­
ferentia te the devices. Unlike the adherent dOt catheter,
whic h is composed of one membrane-covered wire, the
grafr thrombectomy ca theter is constructed using twO
helically arranged exposed wire~ . T hese tWO wires are
d iscally mounted on a central retractable wire in an
opposi ng ldt-handed and right-handed helical arrange­
memo In both ca rherer designs rhumb-activated retrac­
don of rhis centra l wire causes the respective coils (Q
expand in dia meter. T he lack o f a latex membrane cov­
ering over rhe helica Jl r arra nged wires makes the graft
rhrnmhecromy c.-u heter parricularly well suiled for
removal of adhe rent throm bus oc d isrupted neoinrima
common ly as!>ociatt:d with symher ic grafts.
c
FIGURE 34.3 Adherent ClOt catheter: (A) catheter
tip In Its COllapsed, lowest-profile setting; (8) cath·
eter tip In medl um·profile setting showing partiall y
retracted thumb lever; (el fully retracted and
expanded catheter tip.
Surgical Technique
Removal of Adherent Thrombus
in Native Vessel
The follow ing is :it de~c ri p[ion of an angio<,(;opy-asc;isted
[hrom~omy of the superficial fe moral artery and
poplitea l arrer)" containing fresh throm hus with under­
lying adherent cloT.
Aftt:r the angios.cop)' system is white-balanced and
prepared fo r use, a t,trm d;ud cutdown is madt" OVtr t he
femoral triangle. Va~c u lar clamps are applied to the
proximal superficial ,lOd the deep femoral arteries. An
3T1eriotomy is made JUSt proximal to the br.1nch of the
deep femoral artery in the superficial femora l artery. A
sta ndard 3 or 4 Fr balloon embolectomy catheter is
used to remove soft thrombus in the major vessds of
the femoropopliteal srstem .
It is usdul, in fact impt:rativC", to reconStruct the d ot
with removed clot segments on a towel to provide in­
sight imo the anatomic location, structure, dimensions,
and char:lcter of rhe d ot. Otten a meniscus is formed at
the distal end of th e thrombus at the flow boundary of
th e dista l pa rent br:mch. Reconstruction of the clot with
FIGURE 34.4 Adherent clot cathetEr retrieving
adherent thrombus.
Chapter 34 Angioscopi ca1\y A!isisted Thromboe mbolectomy
A
B
-
-Cf\~~=lF
'1 ~~<
==""'=:J
-'C7vJr
FIGURE 34.5 Graft thrombectomy catheter: (Al fully
collapsed (adVancing I position ; (BI fully retracted
and expanded positiOn showing fully retracted
thumb lever.
a recognized meniscus may indicate that the dista l end of
the d O( has been removed, and furt her angioscopic eval­
uation of rhe blood vessel may be iniciated.
At chis point in the procedure, the angioscope is ad­
vam:ed through the arteriotomy and is passed to the: dis­
tal popliteal region. TIle walls o f the Vessel are inspected ,
,1Ild any residual material missed bl' the balloon catheter
(e.g., adherent thrombus, intima l flaps) is noted. Because
ll1timal flaps ma~' appear motionless against the vessel
\vaU unde r steady· fl ow irri gation conditions, one may
consider usmg a pulsing irngati on s}'stem, which may
more accu ra tely mim ic aneri:!1 blood flow, allowing
ViSll(\ !iz..1 tion of rhyth mic intHnal fl ap motion. Should
aclherem clot be detected angioscoPlcally, it can be
removed using the adherent cl ot ca th ete r. This procedure
is repe::ned in the femoro poplitea! )j',t em umil the ves­
sels are ans ioscopica lJ y visualized completely free of soft
and adherent thrombus and a therapeUTic effect is
achieved. Vascubr occlUS ive devices are removed, and
the incisions are cl o~ed in standard fas hion.
Graft Thrombectomy
The revasculariza ti on procedu re using the graft throm­
bectomy catheter in synthetic grafts is very similar to
thrombectomy performed with {he adheren t dot ca th·
erer in native vessels.. An jm.:ision should be made over
the distal anastomotic site amI 3 graftotomy made 3l rhe
Junction of the native vessel and the graft prosthesis. A 5
or 6 FI balloon catheter is then used to rem()Ve soft
throm bu ~. This procedure is repeated until no more
residual material is removed. &11l001l thrombectomy may
occasiona lly resu lt in weak Of even nonexistcll( flow. In
these in ~ta nces (he more aggressive graft thrombectomy
cathete r ~ hould be used to thoroughly remove the
ohstructive , dense"ly adheren t residua l thrombus.
In a re vasculariz.:uion procedure involving an aorto­
bifemoral graft, a No. 8/14 Fr or No. 8121 Fr occl USion
balloon catheter (Baxter Ht:ah hca re Corp., Vascular
Division, Irvine, Calif. ) is threaded through the helical
wires of the graft thrombectomy cathete r, adv<lllced to
(he iliac bifurcation, inflated, and ad jusced until the
su rgeon is satisfied that hemostatic cont rol is achieved.
451
T he grafr thrombectomy catheter is guided along the
shah of the occlusion balloon catheter to a si te immedi­
ately disral to the inflated balloon just below the iliac
bifurcation. The thumb-activated lever on the handle of
the graft thrombectomy catheter is retracted, coiling
the d ista l tip o f the catheter to grasp adherent material.
T he ca theter is wit hdrawn from the artery, and adher­
ent thrombus IS removed from the hel ica l wire elc:ment
(Figure 34. 6) . R epea t~ d passes with the graft thrombec·
tomy cathete r, alternating with ang ioscopic inspection
of (he vessel, shou ld be comi nued until the graft is doc­
umented to be clear of throm botic debris by d irect
vis ual assessment.
PeriodICally, the occlusion ba lloon catheter may be
partially deflated to evaluate" flow improveme nt as an
adlunct to angioscopic inspection. When sa tisfi ed with
the therapeutic result, the occlusion balloon is defl ated
and removed. TIl e graftorom}' closure may then he
completed and th e i llci~ion closed .
FICURE 34.6 Graft thrombectomy catheter thread·
Ing an occlusion ba lloon cathete r, removing adher·
ent thrombus In an ileobifemora l synthetiC graft.
4 52
Pan V Occlusive Arteria l Diseases
Conclusion
Despite the many benefi t.. afforded vascular surgeons
from dirC(,;t vi:,ualizat;on with angio$copr, harriers exist
that prev!;'nt widesp read adoption o f rh e lll odality (3).
Some of the disadvantages associJted with usc of
angioscopy are cost of l1lstru1l1entJtion, fra gility uf
eq uipmem, espeC ia lly opt ica l fi bers, inability to US~ ~n
angioseope concu rrently with therapeutlc modahtles
ow ing 10 small vessel sIze re lative to tht: size of the
devices, inability lO quantit;] £t> flow, d ifficu lty na vigat­
ing tonuous vessels, a steep learni ng ~ u rvc, and .possi­
hie d in ic:"! 1 disadvantages such as mismtt:rprctanon of
da ta, system fl uid overload, traurnatk intimal injur}',
and potential emboli z,nion or thromb(J)I~.
To expa nd upon ,ome of these drawbacks to uti ­
li zation, one pnmary ohsrade IS the cost of angioscopic
equi pm(Cnt . Thc Initial monetary investment to procure
a dedicated angw5COj)IC system, incl uding the ligh t
source, camera, video monitor, pu mp and irrigation
components, can be SIgnificant (:;lpproximarely $60,000
to $65,000). RepaI r of ex pc n ~i"e reusable ::mgioscopes
c;ln easily al1lount fO half as much as the original pur ·
chase COSt and mily run approximareler $2500 to
$3000 pel" repai r. Choosing to milize Jess expensive dis­
posabl e angioscopes Inte rfaced to exisring camera and
monitor endoscopy or laporo5coPY systems wdl allow a
facil ity to .. et up an angio~copic ~ervlce fo r a fr action of
the cost of purchaSing a dedicated system (approximate
$SOOO cm t wou ld Incl ude purcbase of an irrigation
pump, twO angioscopes, and a came ra. cOllpler. unit),
bur the COSt of replacing single-use angloscopes IS also
nor insignificant.
A secondary dererrent to adopting this technology
has been the learning curve associated with system opec­
arion, which reqUIres an understanding not onl y of
device function and application, bLlt also of its mainte­
nance. However, as angioscop~ instrumenta tion usage
increases and the full potentia l of the device is recog­
IlIzcd, the technical learning curve should decrease as
experienced operators include angioscopic assessment III
thelT surgl,,:lI repertoire and surgical tra in in):!, programs
includt' thl~ nt'w modality in their course curricula.
In the past ready J.t:ceptance of the device was
thwarted bv tht' somewhat limited aV:libbilit y at tec h­
nical supp~rt. fhis situation is changing as the two
n,.,in suppliers of the devices. serlling the vascular COl:1 ­
mUllity have expanded their clinical person nel to ofter
physicia ns more opponU l1ities to gai n "1.1a nds"on"
experience eval uating angioscopy sysre ms m climcal
settings. T hl" rwo L(Jns istent man uiclcrurers providing.
angioscopic eq uipment are Intr:lrned (S,IO Diego, Ca lil.,
dis{ r i b u t~·d b~' Baxter Hea lthc.a re Corp., Vascula r Divi­
sion, Irv ine, Calif.) and Ol~mpus (Lake ~uccess, N.Y.l.
O lympm manufactures a broad range of rcusa ~ 1c
ang i l)SCOpe~ fm vascular and other med ical speclaltlc"I
while In tramcd markets, primarily to the vascu lar com ­
munity, ks~-exp ensive disposa ble ang ioscopes or the
new ly int rod uced "respo~ablt" (li mited reusahi lity)
angioscopes. It is likely that other eq uipment manufac­
rurers will enter the fiel d in the fueure as the endovas­
cula r surgical communit), recogni;>;es the value of using
this technique, \vhich will Significantly improve th e ac­
ce%lbility to the ll1strumeIHatio n and the technical sup­
pon serViCes.
Despite some of the ohstacles to rea dy acceptance
of this moda lity, the positive fi nancial Impact angios­
copy may have on the net COSt of surgica l II1rervent ions
should be considered. h is becoming mcreasmgly
Jpparent fh ar cost savings may he realized in several
uelS, such as decreases in proced ure time, operating
room rime, anes thesia time, often pmtopcrat ive hospi­
[<ll i1ation time, an d th e dIrect cosr savings aSSOCiated
wirh eliminating th e completion angiogram .
Trad itionally, thrombectomy was performed as a
semiclosed, blind techni que. The ahility to cl early and
comp lete ly VIsualize the intraluminal fi eld with fl exible,
m,llleuver:lble :lngjoscopes has shed new light on
duomboembolectomr and in situ and synthetic bypass
grafts procedures, as well a prov iding the abili t}, to
evaluate hemodial}'sis access shums.
T he growlIlg trend in vuscIIL.1c surgery is toward
lllltlimally invasive surgica l inrervenrion . Angimcopy
provides opportunities to perform these procedures With
greater efficacy and safery. Despite some of the currene
barriers to us ing angioscop)" this method of Visuali za tion
has real ut ili ty in the thromhoemho lectomy process.
Angioscopy allows for a thorough intralum ina l IIl spec­
tlOIl o f blood vessels in three-di mensional, f(,al- time,
color images that are a fam il ia r visua l modality for
..urgCOI1S. Pathology o ften missed by Doppler ultrasound
or angiography, such as intimal flaps. can be a..scssed
with greater accuracy and acuirr (12 ).
Tec hnological advances in Image quality and reso­
lu tion, along with an incre:lsed ability to lllterrogare
sma ll er vc s~ el~, should sign ificantly improve curren t
a l1 g i mC(~py ~p tems and cn h:ll1 ce their acceptance hy
the surgical community. T he use 01 angioscopy to gu ide
c: n dova~cular surgical intervenriolls will become routine:
in the futu re. The information dire([ ,·isualiz.a.tion pro­
\'Ides IS Vital to ad\'unclIlg the development of ne:w
endo"ascular therapeutic tllod,liit ies .
References
1. foga rty T(, Cr~nlc y JC et (d. A mer hoJ for exn·acri(.ll1
of arterial emboli and th rombi. ~l!l·!; (;ynecol O bsrc!
1963;Fcb:24 1- 244.
2. Thomp~on JL Vascular surgicll l lt',hmques: a hi5IO rie,\1
pcrwenive. In; Bergan JJ, a nd Yao JT, ed~. Technique.~
in :lrtl"rI,,1 wrgl"ry. Phihldelphia: WS S;lImders,
t990:3- U.
J. Tawes KL Jr, Harm lJ . el al. Arterial {hromboembolism;
a 20 year pcrsp<X{ive. Af(:h Surg 198.1; 12U:.595"- 5"99 .
4. Elliott WfT, H agenun jJ-'t, ~t al. Arrena l emhohatl on:
problem of sou rce, multiplicity, recurrence and
rrCor!l1ClH. Surgery 1980;8!:!:!lJJ- H45 .
dday~d
Chapler 34 Angioscopically Assisted Thromboemboleclo my
5. Abbott WM, Ma loney RD, et a1. Arterial embolism: J 44 )"e~ r perspective. Am J Su rg 19112;143:460-464. 6. Cambt'IJ RI), Abbon WM. Ac ure arterial fhrom ho~ls of
the lowe r exrremity: irS nalural hi)wry eonlrasreU with
.merial embolism. Ar(;h 5urg 1984;1 19:784-7IP.
7: Wh i t~ GH, Whicc RA. Introduction and o \'cr-.-iew. In: Angiosco py: \'a~(;u[:lr a nd cor{)narr J.p pli<:3tinns. Chicago: Ynr Book Medical Publisncrs. 1989: 1. R. Stone-bridge PA, Muric IA. Angioscopy: 3 n ew light on
penpheral VR)(;Ui.U disease. Eur Vase Surg 1992;6(41:
346-353.
9. Whi te GH, WhHe RA, er ::. 1. Im rapc nmve video Rngioscop)' eompil red wit h ::Il!eriography d ur in ~ pt'r iphera! v ll ~c u lil r o!Xrations. Vase Surg 1987;6: 4!Hl-495. 10. Whit( G H. Ansio~ j) py. SUIS Cl in Nort h Am 1991;
72(4 ):791-82 1.
J I. G\.lgub kis AG . ( jairzsch A. Vasc ular cnJ oscopy­
;lnglOSCO}l)': (llrrenCindkarioll" A tn iew of t he 'itera·
nu e. Vasa 199 1;20(3): 199-2U6 .
453
12 . Maini 85. And rew ... L, rT al. A modified lI ngioscorkally
<lsslSIcd technique fo r m-Sltu sapheno us vein bypass;
impact on patenCy, complications, li nd k ngl h of sTay.
J Vase Surg 1993;1 7: 1041-1 049.
13. Mille r A, Srom bndge PA, er al. Continutd t'(perience
wit h iOlraoperatlVf angloscopy for mon itori ng mfra·
inguinal bypau grJ ft. Surgery 1991; 109 :Z86- 2!lJ.
14 . FClgJ.r!)· TJ. Hcrmann CD. Angioscopy·assis(cd
Thromboembolectomy. In: Vao JT, Pearce \'('H, eJ~.
Tech rlo losic~ in va~cular surgery. Ph iladelphia; WB
Saundrr;., \ 992;14:3U6- 3 16.
15. Miller A, j t'psol1 5j. Technique of intraoperative
angioseopy In lower c)(trcmirv rev<lscuia rizaTioll . I ll:
Berga n TJ, Vao j T, cd .... Tcchmqul'S In arceri;l! SUf!!-ery.
PhiladelphIa: \'(11\ S a u n dc r~, 1990:409-4 16.
J6. M iller A. Angio$copy: Introd uction and basit" t'!.: h·
niq ues. Presented at r ropess III Angios!.:o py, Intt rven­
tional and Mo nito ri ng Tt'chniques in V;1M;u b r Surgery,
lloston, Decemher 6-8, 1993.