Departent of Health and Human Servces

OFFICE OF

INSPECTOR GENERA

PEER REVIEW ORGANIZATION (PRO)

CRITIERIA FOR

CAROTID ENDARTERECTOMY

AUGUST 199 OEI-t3-91-O150  EXECUTIVE  SUMMAR 
PUROS 
Ths report (1) compares Peer Review Organitions' (PRO) preprocedure review 
exaes 
criteria for caotid endarterectomy and (2)  how these criteria afect denial 
rates. A companon report entitled ''Preprocdure Review Costs for Caotid 
Endarterectomy" (OEI-03-91-O152) determed that preprocedure review for carotid 
endarterectomy was not cost effectie. Ths additional analysis was conducted to
determe if PRO criteria afected these outcomes and whether selected criteria would 
result in higher denial rates. 
BACKGROUN 
Surgeons perform caotid endarterectomy when the carotid arteries leading to the 
brai are blocked and blood flow becomes restrcted. The procedure involves 
disecting the neck below the ears, cuttig the caotid arteries open lengthwise, and
removing the accumulted plaque. 
The Health Cae Financing Admtration (HCFA) required preprocedure review for 
al carotid endarterectomies covered by Medicae until October 1, 1991, when all
eliated. 
requied preprocdure 
reviews were  However, a PRO may request to 
ca 
continue preprocedure review if it  prove it is cost effective and would improve 
quality of cae. 
Under preprocedure review, each PRO developed review criteria and diagnostic 
indicators for approvig caotid endaerectomy. Criteria are general standards on 
which PRO approval is based; diagnostic indicators are measurements or test results 
which substatiate the criteria. 
There is no national consensus on when carotid endarerectomy is appropriate. 
Ongoing National Institutes of Health studies are addressing this 
issue. 
MEODOLOY 
We analyzed all PROs' 1991 preprocedure review criteria for 
caotid endarerectomy. 
We compared criteria by State and identied the criteria which PROs used most 
frequently. We analyzd the number of PRO preprocedure requests and denials by 
State, and compared denial rates for carotid endarerectomy among the different 
criteria tyes. 
FIINGS 
Two-thids of PROs use three priary medical criteria to evaluate carotid 
endarterectomy: 
syptomatic stenosis , and stroke 
, asptomatic stenosis
history.  Diagnostic indicators used to substatiate medica criteria var from PRO to 
PRO. 
The relationship between PROs' criteria selection and denial rates is uncertai. 
Statistically, stroke hitory had an impact on denial rates. However, this impact 
should be viewed with caution since it is skewed by one State s high denial rate. 
PROs in eight States accunt for 
79 percent of al denial. Yet, they share the 
same criteria and diagnostic indicators as PROs with no denial. 
Except for patients with severe syptomatic stenosis, the benefits of caotid 
endaerectomy are unclear. 
CONCLUSION 
Under preprocedure review, the PROs alowed caotid endaerectomy surgery for a
wide range of diagnostic indicators. Diferences among PROs may have resulted from 
outlg 
the lack of objectie medica data  when caotid endaerectomy was
beneficial. It is difcult to develop crteria for preventig unnecess surgery when 
there is no clear data on when surgery is necessary or beneficial. 
When creatig criteria for surgica procedures where there is little objective medica 
data PROs have two choices. They ca alow surgery for a greater range of 
diagnostic criteria where the benefits from the surgery have yet to be proven. Or they 
ca deny surgery for al but a very select subset of crteria. 
However, there is no perfect choice. Under the 
fist option, there may be certai 
patients who have surgery that future research proves is unnecess 
and ineffective. 
The second option may exclude patients from havig surgery that is later found to be 
effective for their paricular circumstances.

When reviewig the PROs' criteria in light of the new research on caotid 
endarterectomy, most PROs seem to have selected crteria that would fall under the 
fist option. As of this time, research has proven caotid endaerectomy beneficial 
th 
onl for patients with severe stenosis (70 percent or more). For  paricular
crterion, the majority of PROs alowed surgery when there was stenosis of 50 percent 
or more. 
The PROs' caotid endaerectomy criteria did not have a clear effect on denial rates.
Th  eliate 
conclusion provides further support for HCF A' s decision to  the 
preprocedure review requirement for carotid endarterectomies.  ................. 
.. . . 
. . . ..  ...   ...   ....    ....    ....    ....    ....    ....    ....    .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     .....     ....    ....    .. .. .  . ...    ....    ....    .. .. . .   ....    .....    ..  ...  .. 
TABLE OF CONTENTS

EX S'y 
.......................................... i

INODUCfON 
FIINGS

Medca Cr1:ri . . 
. . . . . . . . . . . . . 6

DigI()tic  Indicators  .............................................. 6

Deni Rat: 
Crteri  and  .......................................... 8

Stat: with IIer Deni Rate  .. 12

Benefits of Surery 
CONCLUSION 
Proc 
APPENIX A: Deption of PRO Prprocure Revew  .......... A
Deni 
APPENIX B: 
PRO Prprocure Reqests and  B-1 
APPENIX C: Matr and Syop of State Crteri . . . . . . . . . . . . . . . . . . .. C INTRODUCTION

PUROSE 
Ths report (1) compares Peer Review Organitions' (PRO) preprocedure review 
criteria for caotid endarterectomy and (2) examies how these criteria affect denial 
rates. A companion report entitled ''Preprocedure Review Costs for Carotid 
Endarterectomy" (OEI-03-91-00152) determed that preprocedure review for carotid 
endarterectomy was not cost effective. This additional analysis was conducted to 
determne if PRO criteria affected these outcomes and whether selected criteria would 
result in higher denial rates. 
BACKGROUN 
Cati Ar Occlun:  an Treatm 
Causes Riks 
As shown in Ilustration I, two internal carotid arteries provide the brain's primary
blood supply. Individuals often experience atherosclerosis of these arteries as they 
age. Atherosclerosis is the accumulation of plaque or lesions inside the arterial walls. 
Carotid Areries 
Ilustration 1: 
Internal carotid artery

Carotid bifurcation 
Right commn artery 
eft comn 
carotid artery  /:.:?(. 
. . , _.  ?/.":., \:  ::;: :": ::: . . ::.:: ':. ',' :." .. . ' , 
Atherosclerosis causes the caotid areries to narow in siz; thi narowng restrict 
blood flow to the brain producing potenti  (se Ilustrtion II).
health riks 
Individual usually can tolerate grdua oclusion or blockae of one caotid artery.
However, serious occlusion of one or both areries ca caus masive strokes or
traient  (TI). 
ischemic attacks  Tranient ishemic attacks are llmi-strokes . caused 
by a temporar decrease in the brai's bloo supply. 
Ilustration II: Constrcted Arety

Resultin  from Atherosclerosis

Normal 
artery
Constricted  diameter 
artery 
diameter 
3; ' 
Artery  Plaque  Lumen

wall  (clear space)

lesions

Occlusion of the caotid areries ca be treated surgicay or non-surgicay. Caotid 
endaerectomy is the preferred surgica procdure. It involves disectg the neck 
below the ear cuttg the caotid areries open lengtwi, and removg the 
accmulated plaque. The procdure enta 
considerable riks and side effects. 
However, neurosurgeons and vascular surgeons clai high rates of success in restorig
blood flow. 
The most common non-surgical treatment is anti-platelet medication, usually aspir.
Clca 
studies show an aspirn every day 
reduces the rik of stroke. Other drug 
treatments are now being evaluated.  In recent year, the frequency of caotid endaerectomy has not increased due to 
medica appropriateness questions surroundig the procedure. Concerns include the 
quacations of physician performg the surgery, surgica settings, post-surgica 
Pr 
mortty 
neurologica deficits, and high  rates. 
Rev 
PRO 
In each State, HCFA contract with a Utiltion and Quaty Control Peer Review 
Organtion, commonly known as a PRO, to review the appropriateness and qualty 
of surgery performed on Medcae beneficiares. 
Prior to October 1991, HCF A required PRO preprocedure review for 
al carotid 
endarerectomies covered by Medicae. On October 1, 1991, HCF A eliated al
1 However, a PRO may request .
requied preprocedure review.
 to contiue
ca 
preprocedure review if it  prove it is cost effective and would improve qualty of 
cae. At th time, HCFA has not given approval for any PRO to perform
Pr 
preprocedure review for 
caotid endarterectomy.
Re Cr Il 
IndCion 
Dign 
Under preprocedure review, each PRO developed review criteria and diagnostic 
indicators for approvig caotid endaerectomy. Criteria are general stadards on 
which PRO approval is based; diagnostic indicators are measurements or test results 
which substatiate the criteri. 
Typically, PROs had commttees which developed criteria and diagnostic indicators in 
consultation with State medica asociations and a variety of individuals. 
In large 
States, specialty societies, such as vascular surgeons or neurosurgeons, were involved. 
In smaler States, the commttees solicited individual physician opinons. 
The PROs submitted the criteria and indicators to the HCF A regional offce, which 
reviewed and approved them before they could be implemented. Once HCF A 
approved the criteria, the PROs were requied to share them with providers. 
A description of the PRO preprocedure review process is in Appendix 
1 HCFA, Directed Change Order (DCC 91-
13): Cesstion of Preadmision! 
Preprocedure Review. The HCFA does alow preprocedure review for approved 
objectives, interventions under the quality intervention plan and asistats at cataract 
surgery.  Stu 
Rean 
The National Intitutes of Health (NIH) is supportg two large, multi-intitutional 
randomied tral. Both the Asymptomatic Caotid Atherosclerosis Study (ACAS) and 
the North America Symptomatic Caotid Endaerectomy Trial (NASCET) 
Collaborators examie the effectiveness of caotid endaerectomy in reducing arterial
2 Effectieness of caotid endarerectomy 
occlusion and preventing strokes.
is also 
being examed in the European Caotid Surgery Trial. 
NI  Clca  detag 
In Februry 1991, the  isued a  Alert  the benefits of caotid 
endaerectomy for cert indidua. The Agency for Heath Cae Policy and
Research with the Deparent of Health and Human Servces has 
alo issued 
report reviewig recent medica literature concerng caotid endarerectomy. 
MEODOLOY 
Coll 
Da 
We obtaied the PROs' prospective review criteria from HCFA We confed and 
updated the criteria with 47 PRO offcial representing al 50 States, the District of 
Columbia, Puerto Rico, and the Virgi Islands durig March 1991. In this report we
refer to these 53 jursdictions as States. 
From the PROs we requested numerica data and a description of their review 
procedures. The data requested for caotid endaerectomies included the number of 
preprocedure requests and denial.  We asked States to provide us with caenda 
year 199 data. However, some States supplied data from the Thd Scope of Work
for contract year 199. Ths inormation is presented in Appendi B. 
North American Symptomatic Caotid Endaerectomy Trial Collaborators, 
Beneficial Effect of Caotid Endarerectomy in Symptomatic Patients with High-
Grade Caotid Stenosis  New England Journal of Medicine 1991;325:445-453. 
'MC 
European Caotid Surgery Trial: Interi Results for Symptomatic Patients 
with Severe (70-99 percent) or with Mild (0-29 percent) Caotid Stenosis (UK Medical 
Research Council),  Lancet. June 25, 1991; 337(8752):1235-1243. 
S. Deparent of Health and Human Servces, Public Health Servce
, Agency
for Health Cae Policy and Research, Offce of Health Technology Asessment, 
Carotid Endarterectomy (revised1  AHCPR Health Technology Assessment Reports 
July 1991, Number SR. 
The PROs report that fial denial data could change as some denials were 
subject to reconsideration appeals.  Da 
We analyzed al PRO criteria for caotid endarerectomy. We then 
identied the 
crteria which PROs used most frequently. Basd upon advce from our health care 
consultant, we narowed thi selection to threes pirmia r medca crteria. We clasifed 
with 
inormation  the three criteria based on  medica defitions. The PROs 
do not always use simar term to descrbe medica criteria. Therefore, we sometimes 
use one partcul term which is representative of the PROs' varous termologies. 
priar 
We categorid each PRO by the tyes of  crteria it usd. The PROs fell into 
four categories dependig on the combination of the three crteria they used. To
determe if PRO crteria afected denial we caculated the number of denials for 
each of the four categories. We then compared denial numbers and rates among the 
four groups. To test for dierences between the groups, we used a 
liear logitic 
analysis of categorical data. Each category of criteria was entered into the model and 
the signcace of the estiated coeffcients determed using Wald chi square 
statistics. 
Consultat servces were secured under contract from the Vilanova Uniersity College 
of Nursing. 
W. Hosmer and S. Lemeshow  Applied Logistic Regression (New York: 
John Wiley and Sons, Inc., 1989).  FINDINGS 
CR 
TWO-TI  1H PRIY 
MEICA 
OF PROs USE 
CAOT ENARTEMY. 
EVALUATE 
Six-six percent of the States (35 of 53) had PRO criteria which contaed all three 
remaig 
priar medica criteria. The  18 States did not have al three criteria but 
varous combinations of the medical crteria. The crteri were syptomatic stenosis, 
asptomatic stenosis and stroke hitory. Several States alo us criteria other than 
priar 
the three  crteria. 
Symptomatic stenoTsisI is. a  constrction of the caotid arery tht results in physica 
syptoms such as  Asptomatic stenosis is a constrcton of the caotid arery 
resulting in no outward syptoms. A patient's previous stroke experiences comprie 
the stroke hitory criterion. A matri and syopsis of indidua State criteria is 
presented in Appendi C. 
DIAGNOSC INICATORS USE TO SUBANTE MEICA 
VARY FROM PRO TO PRO. 
sae 
Even when States had the  medica crteria, the diagnostic indicators they 
required to substatiate the criteria difered. 
Ste 
Syto11 
Every State used syptomatic stenosis as a criterion for approvig carotid 
endaerectomy. The PROs' criteria generaly included (1) patiTentI .sy ptoms and (2) 
demonstrated stenosis. Accptable syptoms always included  Th-six States 
specifcally mentioned thi term. The other 17 States used more general defitions 
such as indicatig a patient must demonstrate cerebrovaulaTr inIs uffciency syptoms.
A common manestation of such inufcient circuation is a  Some States also 
accpted other neurologica conditions as  consideration of 
syptoms warrting 
caotid endarerectomy. 
States diered in their diagnostic indicators for syptomatic stenosis. Fort-three 
States used percentages which measured the amount of obstrction in the carotid 
arery as diagnostic indicators. Ten States did not specif stenosis percentages. These 
10 States general requied diagnostic test fidigs that confed an atherosclerotic 
lesion. 
For the 43 States using percentages, the percentage of stenosis required for surgery 
ranged from 50 to 95 percent. These States used 60 percentage indicators for 
syptomatic stenosis. Several States used more than one percentage indicator based  on the severity of specifc physica  lowest percentage accepted by each 
syptoms. The 
State is presented in the graph below. 
Variance in PROs' Lowest Acceptable
Stenosis Percentages 
Symptomatic 
EB 
Aaymptomatlo 
r 20

30..  50.,  60.,  70.,  75.,  80., 
Lowest Percentage Accepted for Approval 
43 States Use Symptomatic Percentage.

46 State. U.e 
"symptomatic Percentage.

Ste 
pto11 
Diagnostic indicators for asptomatic stenosis vared widely. Fort-six States 
addressed asptomatic stenosis as a criterion. However, there was little commonalty 
among the diagnostic indicators. 
The 46 States had a tota of 109 diagnostic indicators for asptomatic stenosis. We 
found PROs representing 33 States used multiple indicators for 
thi term. For 
exaple, in Miesota, approval for asptomatic caotid endarterectomy required: 
80% stenosis, or greater than 70% stenosis with ulcerated plaque 
indicated by arteriogram or digita subtraction angiography (DSA), or 
less severe stenosis demonstrated by arteriogram or DSA with one of the 
II on brai-
followig: evidence of "silent-inarcts  afected side indicated by 
cr or MRI or cholesterol emboli to the eye.  Of the 109 diagnostic indicators for asptomatic stenosis 83 included stenosis 
percentages representing the amount of caotid arery narowing. The lowest 
percentage accpted by each State is presented in the graph on the previous page. 
Some States used more than one percentage indicator, depending on other medical 
evidence. The 83 stenosis percentages vared from 30 to 90 percent. Most defitions 
(65 of 83) requied 70 to 90 percent stenosis, unless an ulcerative lesion was present. 
His 
Strke 
Diagnostic indicators for prevous stroke were often loosely defied or 
not addressed.
Th-nie States addressd stroke hitory. Their diagnostic indicators for previous 
stroke fell into five general categories. 
signcat 
Sixeen States requied a stroke patient to have  improvement but did 
not defie duration of the stroke.

signcat 
Eleven States required a patient's stroke to last over one week with 
improvement or recovery of neurologica function. 
Six States accepted strokes without further quacations. 
Five States defied strokes with multiple qualers (e.g., stroke in evolution and 
acute stoke). 
One State required strokes to have occurred withi a certain period of time 
before the review.

CR 
BET 
1H RETIONSH  SE0N AN DEN 
PROs' 
RATE IS UNCETAI. 
priar 
Based on the tyes of  crteria used, the PROs fell into four categories. The 
priar 
categories were: all thee  criteria (syptomatic stenosis, asptomatic
stenosis, and stroke history); syptomatic stenosis and asptomatic stenosis; 
syptomatic stenosis and stroke history; and only symptomatic stenosis. The PROs 
denied 90 caotid endaerectomies out of 53 528 preprocdure requests in 1990 
resulting in a national denial rate of 0.17 percent. Each of the four categories had a
dierent denial rate but al were under 1 percent, as shown in the table on the next 
page. 
The two PRO categories without stroke history had denial rates of 0.44 and 0. 
percent. Statisticay, the two categories have signcatly higher denial rates than 
those which included stroke hitory. Therefore, the decision to include or not include 
stroke history as a criteria seemed to impact a PRO's denial rates. However, the 
cae 
denials for one of the categories without stroke history  from only one State 
Th 
(AZ).  skewig of the data 
indicates that the effect of including stroke history in 
PRO criteria should be interpreted with caution.  .... 
. .. ...  ........ 
..:::" . ........ ... .... ........,. .....:.:............................".......  ".............. ..........,.-............., -,.... ..::. .:.......: :: ...::..:.:.: .,:::..:.:/.:.:".:./.:.:.:."/....::,.....'.:...:.:....   .... ,...,. ..'....... ..""....... ..'."...:.. .. ....:.,....:..."....:............:.......: ..::..... ./:.....::.:.:.. ::...:...:..:.:\ ....,:.':'''...:,. :.:......: ..:..:..:.:... .. ..... .,
.......... .......................... ..".......... '" .... . ............ .......':..:."):..:.:..
Denial Rates for the Four Criteria Categories 
_dr
. n. ..", 
.SteoosIS\/?:  .Pf.  oel8///?  :neniI8'.::.(((. 
t)):" 
41, 
152 
::m:: 
remaig 
The  two categories had denial rates 
relatiely close to the national average. 
States with al thee criteria had an average denial rate of 0. 11 percent and States with 
syptomatic stenosis and asyptomatic stenosis crteria had a denial rate of 0. 
percent. 
StI wi Sytoml Ste Astoml Ste an 
Strke IrlSry 
The 35 States using al 3 priary PRO criteria denied 47 of 41 633 requests. 
However, the majority of denial (34) were reported in just 6 States. Nearly hal the 
States (17 of 35) did not report any denial at 
As shown in the followig table, these 35 States had a collective denial rate of 0. 
percent (47 of 41,633) compared to the national average of 0.17 percent. The 47 
denials represented 52.2 percent (47 of 90) of all denial. 
Denial Rates for States with Symptomatic Stenosis, Asymptomatic Stenosis 
and Stroke History Criteria 
n.... 
. o.

\:::.:N8if6f'  iSstM/Y'::'::'  NO!f6f.:rmHiBi:/  :. ,n:.::, i..  hfb ri9d"': 
Alabama  1074  Not Available  Not Available 
Alaska 
Arkansa  801 
Califomta 
Colorado 
Florida 
Geor la  291 
Idaho  133 
Kansas  132 
Maine  231 
Ma land  870  ... 
. ... .. 
... 
....... 
.....,.. .. .. .......... ....,.............:.?..,).).  . ......,....................,. ... ... ......... . ................ .. \../.,/...'. . ......... .............. ...... ... ........,. ........ :......... .. .. ..... ,....:.:.....:.:..:..:,.: .:..:. p... ............., ...,....... ..................... . . ... ....
NoJdr.  oeid:  NO/d.  1818:'(  ffijrt' Dijl 
Maschuse 
762 
Michl an 
Minnesa 
Misslssi I 
Montana  161

New Je  139

New York  160

130

North Carolina 
North Dakota  127

Ohio

Oklahoma

261 
Puerto Rico

South Caolina

South Dakota  164

Tenness  165

Texas

Vermont

1138

Wisconsin

Tbt i:2'35' StM 
Ste 
Sta wi Sytoma Ste an Aqtoma 
Eleven States had criteria that addressed syptomatic stenosis and asptomatic
Th 
stenosis.  group denied 31 of 7,005 requests. However, the denial rate in the 
States was afected by just 1 State, Arona, which reported al 31 denial. At 5. 
percent, Arona had the highest denial rate of all States. As shown below, Arona
denial rate was more than 30 times the national average of 0.17 percent. 
Denial Rates for States with Symptomatic and Asymptomatic Stenosis Criteria 
'::NaJ8fR':::::: ues/i  j(NoHibeniai/)  /\Percrtb&1i&f

Ariona  542

Connecicut

Delaware  130
 ..  ... 
:....:.......:........:......:.......:.......:.... ..)......)...."....)........ '.... . ...... .... ............... ........ .... ......... ......... ........... .......,."..." ...,.."...........,.,...... .'......... ..........-..............-..,..... ....,.."........,..,......,.........................................................................'....... ..."....... .......)...... .......... ?".......... .. .......)...............'...... .................................................  ......:.'....................' ...  . ... . ........ ...  ..................... . .. ...................................................... ............................................ ... ........ ..... .. ..........................  ............. ....... ............................................................................../... ...:......:.........:.......'..... . ."./..'...).....)..
. .).......'........ .....' . .".... ..,. . ..., ...".-..........,............ ..................................... ................... ....,.............................................. ......... ......'..".......'... .....,,...... .... . ....,..,.... .... ........................... . ......"......... .. .......'.. . ...'....... .....'. ....'.."' .'....'.'.."..........."............'....'.......''..'..'....''..'....''.....'.'..'....' ...'....'..'......'....'.....'...'......'..'....................  .............'..... ............ ..... .................  ...'..'....... .... ........ ............................... ........... .. .............
?,N()Bfff.  esriF  \iN6?bfDihiii:.'...  n....  r.".p tditdjiH 
HawaII  102 
illinois 
Indiana  150 
Kentuc 
Nevada 
New Mexico  127 
674
..... ..... n... 
::tr6tal(::::::t1  ittttt\tf1mrtmHrrf:: 
Syto Ste 
Str 
Sil wi  an  Hisry 
Four States with criteria addressing syptomatic stenosis and stroke history denied 4 
367 requests. The 4 denials represented 4.
of 3, 4 percent of all denials  (4  of 90). 
Collectively, these States' denial rate of 0. 12 percent (6 of 3 422) was comparable to 
the national average of 0. 
17 percent. 
Denial Rates for States wit Symptomatic Stenosis and Stroke History Criteria 
)m):.:)Statit?t::t.:tt.:::.)::?::....  ///N8HSfFf..OBtt')(:\  N8i6f'bii8'''  :tttt'pircenFbenkKi'm?t:\):tt 
Louisiana  135 
Missuri  166 
New Ham hire  137 
Utah  214 
ff& F;;.4StMmr 
Sil wi Sypto11 Ste Crn On 
The three States with criterion addressing only syptomatic stenosis denied eight 
requests or 8.9 percent of all denials. Whe these three States had a collective denial 
rate of 0.53 percent (8 of 1 523), six of the eight reported denials occurred in one 
State (Iowa). 
Denial Rates for States wit Symptomatic Stenosis Criterion Only 
N6fbfi=f..  .N6J' 6fDenlahf.  ':/(PercentDerl9a9 
Iowa 
Nebraka 
Rhode Island  130 
"TOtaV.'  Sime..  DEN
PROs TIN Im GSmH ST ATE AaDUCN FROR 7 9 PERCE OF AI 
SA 
WI  DTHE N  AN DIAGNOSC INICATORS 
AS PROs  NO 
th 
The PROs in eight States reported more  thee-quars of al caotid 
endarterectomy denial in 199 (71 of 90). The caus of the higher denial rates in 
these eight States was not due to any parcular combintion of crteria or diagnostic
indicators. In fact, other States with exactly the same crteri and diagnostic indicators 
as some of these eight States had much lower denial rates. 
These eight States had varous caotid endaerectomy crteria and diagnostic 
indicators. In six States (CA, CO, MI OR, TN, and VA), PROs addressed al three 
national medica crteria. The Arna PRO criteria addressd 
syptomatic and
asptomatic stenosis. The Iowa PRO criteria address onl syptomatic stenosis. 
Each of the eight States had four or more denial for  durig 
caotid endarerectomy 
199. The 71 denial (out of 14,711 requests) resulted in a denial rate of 0.48 percent, 
alost 3 times the national average of 0.17 percent. These States, however, accunted 
for only 27.5 percent of al preprocedure requests. 
EXl.H1 FO  PATI WI SEVE SYMATIC STOSIS 
CAOT ENARTEMY AR UNCL 
EN.tTl  OF 
Two recent studies have concluded that caotid endaerectomy is beneficial for 
syptomatic patients with severe or high-grade stenosis (70 percent or more) of the
internal caotid artery. However, no signcat boy of medica inormation shows 
that carotid endarerectomy is effective for lower-grade syptomatic stenosis or for 
asptomatic stenosis. 
Severe syptomatic stenosis is the one criterion where medical consensus exists. 
The Nort America Symptomatic Caotid Endaerectomy Trial Collaborators 
TI 
concluded that caotid endaerectomy is highy beneficial for patients with 
non-disablig strokes who have high-grade stenosis. The European Caotid Surgery
Trial alo founsd ttheatn caootsidi esn.d arerectomy was useful in treatig stoke patients with 
severe caotid 
The benefits of caotid endaerectomy are not as clear for mid 
(0-29 percent) to 
moderate (30-9 percent) syptomatic stenosis or for asptomatic stenosis. 
However, the European trial found that for mid stenosis the results indicated that the 
riks of surgery outweigh the benefits. 
Among the 43 PROs who specifed syptomatic stenosis percentages, 2 States' lowest 
accptable percentage for surgery was 75 percent and for another 4 States it was 80 
percent. However, the majority of States allowed carotid endarterectomy for 50 
percent or greater syptomatic stenosis.  CONCLUSION

Under preprocdure review, the PROs allowed caotid endarterectomy surgery for a 
wide range of diagnostic indicators. Diferences among PROs may have resulted from 
the lack of objective medica data outlinig when caotid endarterectomy was 
beneficial. It is dicult to develop criteria for preventing unecessary surgery when 
there is no clear data on when surgery is necessa or beneficial. 
When creating criteria for surgical procedures where there is little objective medical 
data, PROs have two choices. They ca alow surgery for a greater range of 
diagnostic crteria where the benefits from the surgery have yet to be proven. Or they 
ca deny surgery for all but a very select subset of criteria. 
fit 
However, there is no perfect choice. Under the  option, there may be certai 
patients who have surgery that future research proves is unnecessary and ineffective. 
The second option may exclude patients from havig surgery that is later found to be 
circumstances. 
effective for their particular 
When reviewig the PROs' criteria in light of the new research on caotid 
endarterectomy, most PROs seem to have selected criteria that fal under the fist 
option. As of this time, research has proven caotid endarterectomy beneficial only 
for patients with severe stenosis (70 percent or more). For this particular criterion 
the majority of PROs allowed surgery when there was stenosis of 50 percent or more. 
The PROs' caotid endarterectomy criteria did not have a clear effect on denial rates. 
eliate 
Ths conclusion provides further support for HCF A's decision to  the 
preprocedure review requirement for caotid endarterectomies.  APPENDIX A

RE 
DESON 
PREROCUR  PROC 
OF PRO 
The review procss does not vary signcatly among PROs. Physician usuay intiate 
the review procss prior to performg a caotid endaerectomy. However, the lie-
threatening nature of a stroke sometimes requies retrospective approva. 
Re 
for 
Typicay, the recommending surgeon, a sta member, or hospita sta telephones the 
PRO to review the patient s condition aI1d seek preprocedure approval. Most PROs 
also accept mai requests and a few accpt them via facsime machie. 
Re 
Ini Re 
Nun 
by 
Regitered nurses (RNs) review the intial preprocedure request, comparg the 
physician s diagnosis and the patient' s syptoms agait the PRO criteria for caotid 
ca 
endaerectomy. The RNs  approve the request based on the inormation the 
s representative) provides. If the request does not meet the 
physician (or physician 
criteria, the RN refers the cae to the PRO physician advior for review. 
Physi 
PRO 
The PRO physician conducts a second review of the requests which have not met the 
criteria, often contacting the recommending surgeon to  cae further. Afer 
discuss the 
the review, the PRO physician approves or denies the procdure. 
When a PRO approves a preprocdure request, it asigns the cae an approval 
number. When the PRO denies a request altogether, it tyically inorm 
both the 
surgeon and the patient of the decision, the rationale, and an explanation of appeal 
rights.  ... ...... :;' ".. ..  ..  .........
APPENDIX 
1990 PRO PREPROCEDURE REQUESTS AND DENIAS

FOR CAOTID ENDARTERECTOMY

BY STATE

AL 1,
NIA.P .1mCE 
Ai:::i::::::::II:::llj::L::I:I::lllllllilllSl::::11:1 i:1K11!1111.:1:!lii!l:i:il'ji:jllllAii::::I:.IIIIII:II I!:i:-1::::I:I:::::liill:::. )1:1Ii:i:l::lj::J::ilii:::;:  o i:iill:i::I:I!::0:II!::illl:II::::::.::!:::!i!:!!i:iiii 
 :11:11
31 5.

074  NIA
AARRZOSNAA
o 0.

542
CAORNIA 5,801 4 1.

COLORA
043 o 0.a12
CONNECTCur o 0.
DELAWAR  o 0.
130  o 0.
FLORIDA 3, 1 0.

nc
GEORGIA 
869 o 0.

HAWAII
2,941 o 0.
102 
o 0.

InnIMOu NNOO DWIAAA 1,
2,no  6 0.a 00
504  o 0.

KASAS 1,
KECKY 726 o 0.
325 1 0.

LOUISIAA 1, o 0.

356  1 0.

MAYLD 
MANE
870
MASACHUSETTS 
MICHIGA 
762  o 0.a1
 3 
MINESOTA 2,598 o 0.a27
MISSISSIPPI 364
MISSOUR 1,658  o 0.

MONTANA  a12
NEBRAKA 161 o 0.

NEVADA 
667  o 0.0.30
HAPSHIR  o 0.
NEW  137  o 0.
NEW JERSEY 1, 
NEW MEXCO 390  1 0.

NEW YORK 1,1 27 1 0.
o 0.

OCHAOIUONA  1,
NORTH  304
NORTH DAKOTA 
127  o 0.

OKLOMA
2,922 a17
552  ... . :!'.
.. - 
':' :!:.'.:':. . .. ............, .....  ......,....,.
i: . HtpEO\F/\
i)fU 
:lj::f. 
OREGON  786

PENNSYVANIA  2,6S1

PUERTO RICO

RHODE ISLAD  130

SOUTH CAOUNA  460

SOUTH DAKOTA  164

TENNESSEE  6S3

639

UTAH  214

VERMONT

VIRGINIA  943

VIRGIN ISLADS

WASHINGTON  138

WEST VIRGINIA  674

WISCONSIN  935

WYOMING

NADONA TOAL  53,528

ins 
AU data cis daielct ly from PRO  req condte dug th inctn. Some PROs were able to provi
oth 
da for  year 199 as  choe to provi da for th Thir Scope of Work contract 
year 1990. 
. We use th degn n/a to inat tht data was not availe at th tie of OUT inter.  ':::::::::::::::..:.:.:.:.:,: :::::::::::::.'::.":~':::"://~:::~ :. ," :\::':::: (:.::.:.- . "" """"'::"" , : ...  ........
APPENDIX 

MATRI OF STATE CRIRI FOR C.A OnTID. EN.D ARTERECTOMY 
AL 
MA71q::::::)  ::(i  ?J.  ()Kl1)\
ALSKA . 
ARZONA 
ARSAS. 
CAFORNIA . 
COLORA. 
CONNECTICUT 
DELAWAR 
FLORIDA. 
GEORGIA . 
HAWAII 
IDAHO. 
ILLINOIS 
INDIAA 
IOWA 
KASAS. 
KENTCKY 
LOUISIAA 
MANE. 
MAYLD. 
MASACHUSETTS. 
MICHIGAN. 
MINNESOTA. 
MISSISSIPPI. 
MISSOUR 
MONTANA. 
NEBRASKA 
NEVADA 
NEW HAPSHIR 
NEW JERSEY

NEW MEXCO 
NEW YORK. 
NORTH CAOLINA.

NORrH DAKOTA. 
OHIO. 
OKLOMA . 
OREGON. 
PENNSYVANIA . 
PUERTO RICO.

C - 1
 \::.
..  ......
\SY77C\) 
STT.H  ?($TOKE: 
:?JUMA77C(
RHODE ISLAD 
SOUT CAOLINA
SOUT DAKOTA
TENESSEE
TES
UTAH 
VERMONT
VIRGINIA 
VIRGIN ISLADS 
WASHINGTON
WEST VIRGINIA 
WISCONSIN
WYOMING
TOAL 
CRIRI 
* INCLUDES ALL THREE 
C - 2  CR 
CAOT ENARTEMY 
SYNOPSIS OF STATE  FOR 
AlIl 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have latera1d 
tranient neurological 
dysfuction involvig speech, reason, motor, or sensory function, stroke, or drop 
attacks (vertebral-basilar ishemia). And: 
Imagig: 
Angiography must demonstrate stenosis  TI  70%, stenosis  60% with 
ulceration, deep ulceration related to 
or complete uniateral occlusion 
50% on the other side. 
with stenosis 

ASYMOMATIC STENOSIS: The patient must have (1) a brut, ultrasonic stenosis 
70%; or (2) complete unilateral occlusion with 
70%, and angiographic stenosis 

50% on the other side. 
stenosis 
STROKE: Stroke is defied as a recent stroke with goo to excellent recovery of

fuction.

OTHR: 
Caotid-subclavian shunt warants carotid endarerectomy.

AIa* IdD  Wasgtn

d: 
SYNTOMATIC STENOS 
TI 
Symptoms: Patient must have at least one  amaurosis fugax stroke, or 
cholesterol emboli in the retinal 
arery. And: 
Imagig: Imagig must  50% 
be positive for either an ulcerated plaque or 
stenosis on the afected side. 
ASYMOMATIC STENOSIS: Noninvasive study, arteriograph, or digital 
80% stenosis or an ulcerated plaque. 
subtraction angiography must demonstrated 

STROKE: Stroke (CVA) is not defined. 
OTHR: 
None. 
C - 3
 &: 
Arna 
Nevad 
Hawai 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have amaurosis fugax tinglg libs of face 
diess, 
(paresthesia), paresis (or paralysis),  diplopia (double vision), or 
vertigo. And: 
Imagig:  50% unateral stenosis of the 
Angiography must demonstrate 
50% bilateral stenosis internal 
common or internal caotid, 
 caotid occlusion 
50% contralateral stenosis or an ulcerated plaque. 
asocated with 

ASYMOMATIC STENOSIS: Angiography  70% uniateral 
must demonstrate 
internal or common caotid  50% stenosis in the presence of a contralateral 
stenosis, 
internal or common caotid, or a total occlusion. 
STROKE: Not addressed. 
OTHR: 
None. 
SYMTOMATIC STENOSIS: 
TI 
Symptoms: The patient must have clasica  with hemiparesis 
hemianesthesia, or dysphagia lastig c: 24 hours; amaurosis fugax (transient 
monocular blidness); unilateral deficits such as hemiparesis of hemianesthesia 
lastig 24 hours to 7 days; or stroke. And: 
Imagig: 
Angiography must  50% diameter reduction. 
conf 
ASYMOMATIC STENOSIS: Areriogram must  80% diameter reduction. 
show 
STROKE: Stroke is defied as lasting over one week with signifcant recovery of 
neurologica fuction.

OTHR: 
None. 
Clomi 
SYMTOMATIC STENOSIS: 
TI 
Symptoms: The patient must have clasical  (with hemiparesis 
hemianesthesia, or dysphasia lasting c: 24 hours), amaurosis fugax (monocular 
blidness  10 minutes), unilateral neurological deficits (such as 
lasting 
C - 4  hemiparesis, hemianesthesia, or monocul blidness) lasting 24 hours to 
several days (reversible ischemic neurological deficit or RIN), or stroke. And: 
Imagig: Angiography or DSA must demonstrate stenosis of 80% or carotid 
lesion with ulceration, or CAT sca or MRI must demonstrate silent inarction 
with stenosis of 80% or caotid lesion with ulceration. 
ASYMOMATIC STENOSIS: Angiography showig 80% stenosis referred for PA 
review. 
STROKE: Stroke is defied as a stroke lastig over one week with complete or 
nearly complete recovery of fuction. 
OTHR: Asptomatic 
caes in special HCFA study are automaticay approved for 
specifed practitioners and providers. 
Colo 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have one of the followig: tranient monocular 
blidness (amaurosis fugax) with ipsilatera stenosis or plaque with ulceration;
TI 
involvg the anterior circulation with face, arm, hand, or leg numbness or
24-
weakess, aphasia, , or dysphasia for .c  hours traceable to the 
appropriate caotid; or recent CV A. Additionally, the medical record must 
document the neurologica deficit. And: 
Imagig: Areriogram or DSA must show a hemodynamcay signcat lesion
defied as at least 60% diameter stenosis 84% cross sectional area stenosis, or 
ulceration. Hemispheric symptoms alo require a cr scan or MRI. 
ASYMOMATIC STENOSIS: The patient must have a hemodynamcally signcat
lesion, defied as at least 60% diameter stenosis 84% cross sectional area stenosis, or 
, deep ulcerative plaque. 
asptomatic severe
STROKE: Stroke is defied as a recent CV A traceable to the extacranial carotid 
source where the patient made a with functional recovery, but would benefit from 
protection agaist a recurrent event in the ditn"bution of the stroke arery. It also 
includes stroke in progress or acute stroke with 6 hours followig carotid 
endarterectomy or neck trauma. 
OTHR: 
None. 
C - 5
 Coti

SYMOMATIC STENOSIS: 
foc 
Symptoms: The patient must have a  or neurological deficit (transient or 
permanent) compatible with a caotid lesion. Brai imagig must not reveal a 
lesion that could explai the clica fidigs. And: 
Imagig: 
Angiography must demonstrate  60% liear stenosis of the internal 
signcat 
caotid arery, or  ulceration of the internal caotid arery with 
symptoms of cerebrovascular inuffciency compatible with the afected side 
whie on antiplatelet drgs. 
ASYMOMATIC  90% stenosis of

STENOSIS: Angiography must demonstrate 
internal carotid artery in the asymptomatic patient.

STROKE: None.

OTHR: 
None.

Yug 
Dear  d: 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have cerebrovascular insuffciency symptoms. 
And: 
Imagig:  50% unilateral stenosis of the 
Angiography must demonstrate 
50% bilateral stenosis, internal carotid occlusion 
common or internal carotid, 
50% contralateral stenosis, or an ulcerated atheromatous plaque. 
with 
ASYMOMATIC  80% uniateral 
STENOSIS: Angiography must demonstrate 
50% stenosis in the presence of a contralateral 
internal or common carotid stenosis 
internal or common carotid, or 
tota occlusion. 
STROKE: None.

OTHR: 
None.

Dit 
Marla

of 
Coluia  d: 
SYMOMATIC STENOSIS:

TI 
Symptoms: The patient must have 
amaurosis fugax previous 
TI, 
atherothrombotic stroke, stroke-in-evolution, crescendo  or recurrent 
C - 6  global or non-specifc syptoms whie on antiplatelet or anticoagulant therapy. 
And: 
TI 
Imagig: For  or amaurosis fugax angiography or duplex imagig must
fid ;: 50% diameter ipsilateral common or internal caotid arery stenosis. Or 
angiography must fid a large ulcerative TlesIio,n  in the ipsilatera common or 
internal caotid artery. Or for repeated  angiogrphy must fid an 
ocluded ipsilateral internal caotid arery and ;: 50% diameter ipsilateral 
TI 
arery stenosis. Or for persistent focl  despite 
external caotid 
fid 
anticoagut or antiplatelet therapy, angiography must  c: 50% common or 
internal caotid arery  smal ulcerative lesion in the ipsilateral 
stenosis, or a 
common or internal caotid arery. 
For previous atherothrombotic stroke, angiography or duplex imagig must fid 
;: 50% diameter ipsilateral common or internal caotid arery stenosis. Or 
angiography must fid a large ulcerative lesion in the ipsilateral common or 
internal caotid arery. On rare occions it would be appropriate to perform a 
caotid endaerectomy in a patient with an acute stroke if the operation is 
performed shortly after the stroke and angiography or duplex imagig fids :: 
70% diameter ipsilateral common or internal caotid artery stenosis. 
For stoke in evolution, angiography or duplex imagig must fid ;: 70% 
diaeter ipsilateral common or internal caotid arery stenosis. Or angiography 
must fid ;: 50% diameter common or internal caotid artery stenosis and a 
large multicentric ulcerative lesion in the ipsilateral common or internal caotid 
arery. 
TI, 
For crescendo  angiography or duplex imagig must fid ;: 50% diameter 
common or internal caotid arery stenosis, or c: 50% diameter common or 
internal caotid arery stenosis on the side appropriate to the syptoms with ::
50% diameter common or internal caotid arery stenosis on the opposite side. 
Or angiography must fid a large ulcerative lesion in the ipsilateral common or 
internal caotid artery. 
For recurent global or nonspecifc syptoms whie on antiplatelet or 
anticoaguant therapy, angiography must fid ;: 50% diameter common or 
internal carotid artery stenosis, or a large ulcerative lesion in the common or 
internal caotid artery. 
ASYMOMATIC STENOSIS: Angiography or duplex imagig must fid :: 70% 
common or internal caotid artery stenosis. Or OPG-Gee must be positive for :: 50% 
diameter common or internal caotid artery stenosis. Or angiography must fid a 
large multicentric ulcerative lesion in the common or internal carotid artery. 
STROKE: Stroke includes a patient who has suffered an atherothrombotic stroke. 
The patient should not have an incapacitating or profound neurologic deficit but 
C 
 lig 
rather is a fuctional adult  withi the communty. The neurologic symptoms 
should have fuy stabild. 
OTHR: 
None. 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have hemipheric and/or monocular  with an 
(die
appropriate lesion of the caotid bifcation, stroke, or global 
nonfoc) ischemic syptoms with multiple arerial oclusive lesions includig 
high grade stenosis of the internal 
caotid areries. And: 
scag 
Imagig: Nonivasive studies (duplex  or other forms of ultrasonic 
imagig) or areriography  50% carotid stenosis or a 
must demonstrated either 
nonstenotic ulcerative plaque believed to be the source of cerebral emboli 
causing the patient' s syptoms. 
ASYMOMATIC  75-80% caotid stenosis or 
STENOSIS: The patient must have 
large caotid ulceration (complex multiple ulcerations) in selected better risk patients. 
STROKE: Stroke is defied as a hemipheric completed stroke with good recovery
(mial  wag
to modest neurologica deficit). Stroke-in-evolution or waxg-and-
deficit in the presence of an untable caotid  95% stenosis or a highy 
lesion: 
iregular ulcerated lesion not associated with high grade stenosis. 
OTHR: 
Acute caotid thrombosis followig areriography or caotid endarterectomy 
if surgery can be performed withi 1-2 hour after onset. 
Gerg 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have a clasical  (with hemiparesis 
hemianesthesia, or dysphasia lastig c: 24 hour), amaurosis fugax (ophthalc 
arery uniateral inuffciency to 
retina due to internal carotid stenosis 
producig tranient loss of viion), uniateral neurologica deficits such as 
hemiparesis or hemianesthesia lastig 24 hour to 7 days (RIN), stroke, or 
vertebral basilar ischemia (drop attacks). And: 
Imagig: The areriogram must fid a 90% caotid lesion, or an 80% carotid 
lesion with signcat  brai CAT scan must indicate a silent 
ulceration, or a 
inarct-with a 90% carotid lesion, or an 80% caotid lesion with ulceration. 
C - 8  ASYMOMATIC STENOSIS: The patient must have a bruit with ultrasound 
evidence of 80% or greater caotid stenosis. 
STROKE: Stroke is defied as lasting over one week with complete or nearly 
complete neurologica function. 
OTHR: Preparatory procedure prior to performg a caotid subclavian shunt. 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have syptoms of caotid sytem inufciency
(e.g., tranient monocular blidnes or amaurosis fugax hemipheric ischemia 
with weakess of numbness of the libs or face, or aphasia). And: 
Imagig: Angiogram or doppler sca must demonstrate one of the followig: 
50% uniateral stenosis of the common or internal  50% bilateral 
caotid, 
stenosis, internal carotid  50% contralateral stenosis 
occlusion asociated with 
or an ulcerated atheromatous plaque in the presence of cerebrovascular 
inufciency syptoms. 
ASYMOMATIC  70% unateral internal or 
STENOSIS: The patient must have 
common caotid  50% stenosis with a contralateral internal or common 
stenosis, or 
caotid tota occlusion. 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
Ind 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have "focal" cerebrovascular inufciency 
syptoms, such as: amaurosis fugax tinglg libs or face (paresthesia), 
, hemianopia, or sensory deficit. Or the patient must have 
paresis or paralysis
cerebrovascular insufciency syptoms. And: 
Imagig: For "focal" cerebrovascular inuffciency syptoms, angiogram must 
demonstrate an ulcerated atheromatous plaque. For cerebrovascular 
inuffciency syptoms 50% uniateral stenosis 
, angiogram must demonstrate 
of the common or internal caotid  50% bilateral stenosis, or a 
arery, 
severely ulcerated lesion c: 50% stenosis associated with syptoms. 
C - 9  ASYMOMATIC STENOSIS: Angiogram must  70% uniateral 
demonstrte 
internal or common caotid stenosis, or 50% stenosis in the presence of a contralateral 
or common carotid lesion or occlusion. 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
Iowa 
SYMOMATIC STENOSff: 
Symptoms: The patient must demonstrate ipsilateral caotid terrtory syptoms
such as contralateral weakess clumines, paralysis contralatera numbness 
paresthesias, dysarhra, dysphasia, ipsilateral monoclar blidness (amaurosis
fugax), or contralateral homonymous hemianopia (defective vision affecting the 
right halves or left hales of the visual fields). And: 
Imagig: Angiogram  75% uniateral 
or duplex study must demonstrate 
stenosis of the ipsilateral common or internal  50% stenosis of the 
caotid, 
ipsilateral common or internal caotid associated with contralateral internal 
caotid arery occlusion, or ulcerated atheromatous caotid bifcation plaque 
with asocated  50%. 
stenosis 
ASYMOMATIC 
STENOSIS: Asptomatic stenosis is Dot mentioned. 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
SYMOMATIC STEOSIS: 
Symptoms: The patient must have (1) a symptom (transient speech
dysfucton, altered body sensations, gait disturbance, dyhra, sudden 
blidness, tranient hemiparesis, or stroke), and (2) a sign (caotid bruit,
neurological examiation confirmg deficits, or cholesterol plaques in the eye 
grounds). And: 
conf 
Imagig: 
Angiography must  an atherosclerotic lesion in the 
appropriate caotid arery.

ASYMOMATIC STENOSIS: Areriogram must diagnose a 30% caotid lesion or a 
caotid lesion with ulceration, or brain CAT scan must demonstrate a silent infarct 
with a signcant caotid lesion. 
C - 10
 STROKE: Stroke is defied as a stroke with complete or nearly complete recovery of 
neurologica function. 
OTHR: 
None. 
SYMTOMATIC STENOS 
Symptoms: The patient must have either foca cerebrovasular inuffciency 
tiglg libs 
syptoms such as amaurosis fugax 
or face (paresthesia), paresis 
or paralysis hemianopia, or sensry deficit; or general cerebrovascuar 
inufciency syptoms. And: 
Imagig: For foca cerebrovascular inufciency syptoms, angiogram or 
arerial DSA must demonstrates an ulcerated atheromatous plaque. For 
general cerebrovasular inuffciency  or arerial DSA 
syptoms, angiogram 
50% uniateral 
must demonstrates an ulcerated atheromatous plaque, 

stenosis of the common or internal  50% bilatera stenosis, or a 
caotid arery, 
severely ulcerated lesion with c: 50% stenosis. 
ASYMOMATIC STENOSIS: Angiogr or arerial DSA 
must demonstrate 
70% unateral internal or common caotid stenosis, or 50% stenosis in the presence 
of a contralateral or common caotid 
lesion or occlusion. 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have TI CV A, sycope; sudden onset of focal 
dimg 
weakess, diorientation,  of viion, or monocular loss of vision; 
episodic senstion of or loss of consciousness or episodic confion or amnesia; 
sensory loss; or episodic dysarhra or dysphagia. And: 
Imagig: 
Radiography must evidence  70% stenosis 'of the caotid artery with 
or without an ulcerative plaque, or sonography must evidence sigIcant 
stenosis in patients with documented severe allergic reaction to iodinated dyes. 
ASYMOMATIC STENOSIS: Asptomatic stenosis is not mentioned. 
STROKE: Stroke 
is identifed as a CV 
C - 11
 OTHR: 
None. 
Mai 
SYMTOMATIC STENOSff: 
TI 
Symptoms: The patient must have  (motor or sensory), RIN (uniateral
weakess lasting:; 24 hours and -c 48 hour with no fied neurological deficit 
and negatie CAT sca), amaurosis fugax CV A, or basilar-vertebral syptoms
(at least two of diess, sycope, subclavian steal 
sydrome). And: 
Imagig: Doppler, angiography, or DSA must evidence a surgical carotid lesion 
in a suitable surgica 
rik patient. 
ASYMOMATIC STENOSIS: Doppler, angiography, or DSA must evidence 
bilateral severe (:; 75%) stenosis, severe (:; 75%) unateral stenosis with 
contralateral internal caotid arery occlusion, or severe (:; 75%) bilateral internal 
carotid arery stenosis in selected pre-operative patients. In addition, Doppler, 
angiography, or DSA must evidence a surgica caotid lesion in a suitable surgica rik 
patient. 
STROKE: Stroke is defied as CV A with recovery. 
MOTHRt: Nlo ne.
SYMOMATIC STENOSIS: 
Symptoms: The patient must have amaurosis fugax (monocular transient loss 
of viion), CV A, TI RIN, or cholesterol emboli to the eye. And: 
TI 
Imagig: For  or RIN
amaurosis fugax CV A,  , arteriography or DSA 
must demonstrates ulcerated plaque or :; 50% diameter stenosis on the brain 
affected side, or a duplex sca  60 Hz 
must demonstrate sytolic frequency 
5 m/sec. For cholesterol emboli to the eye, areriography or 
or velocity 

DSA must demonstrates ulcerated plaque. 
ASYMOMATIC STENOSIS: Areriograph or DSA must  90% 
demonstrate 
diameter stenosis on the operative side or -c 2 Mm. residua lumen on the operative 
60 
side, or duplex scan must demonstrate 
systolic frequency  Hz or velocity of 
1.5 m/sec, or the patient is preoperative for a coronar artery bypass graft and 
arteriography or DSA demonstrates:; 70% diameter stenosis on the operative side 
and 70-100% diameter stenosis on the non-operative side. 
STROKE: Stroke is defied as CV A (ischemic) with signcant functional recovery. 
C - 12
 OTHR: Patient enrolled in Nl' s Asymptomatic Caotid Atherosclerosis Study

(Toole) or North America Symptomatic Caotid Endaerecomy Study Trial

(Barett) ia an automatic approva.

Mic 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have either (1) hemipheric  (TI
syptoms 
recovered stroke, stroke in evolution, loss of speech, confion, expressive or
receptie languge problems, unateral lib weaes, or paralysis) or 
a(mdauireossis;  fugax (unateral viion loasst)a, o;r  (2) non-hemispheric syptloimbs 
diplopia; blured viion;  drop attacks; or bilateral 
paralis, weakess, or numbness). And: 
Imagig: For hemipheric symptoms, angiography must evidence;: 50% 
stenosis in the ipsilateral internal caotid artery or common caotid arery,
and/or untable ulcerated lesion. For non-hemipheric syptoms, angiogrphy
must evidence ;: 75% stenosis of the common or internal caotid arery. 
ASYMOMATIC STENOSIS: Angiography must evidence ;: 80% stenosis of the 
common or internal caotid arery. 
STROKE: Stroke is defied as recovered stroke or stroke in evolution. 
OTHR: 
None. 
Mmnta 
SYMOMATIC STENOSff: 
TI. 
Symptoms: The patient must have 
amaurosis fugax CV A, or  And: 
Imagig: Areriogram or digital subtraction angiography must indicate 
ulcerated plaque or ;: 50% stenosis on the brai-afected side. 
ASYMOMATIC STENOSIS: Areriogram or DSA must indicate 80% stenosis, or
:: 70% stenosis with ulcerated plaque; or areriogr or DSA must demonstrate less 
severe stenosis with cr or MRI evidence of silent inarct on brain-afected side, or
cholesterol emboli to the eye. 
STROKE: Stroke is defied as CV A (ischemic) with signcat 
functional recovery. 
OTIR: 
None. 
C - 13
 MISpi 
SYNTOMATIC STENOSff: 
foc  (T,
Symptoms: The patient must have stable,  ischemic syptoms 
RIN, 
amaurosis fugax  and previous atherothombotic stroke); stable, dise 
ischemic syptoms; evolvg, foca ischemic syptoms (stroke in evolution or 
TI); 
crescendo  or acute stroke. And: 
Imagig: For stable, foc, ischemic syptoms areriography or duplex imagig 
must judge promient plaque formation in the internal or common caotid 
artery appropriate to the  judge a large ulcerative 
syptoms; areriogrphy must 
lesion in the internal or common caotid arery or areriography must judge an
occluded internal caotid arery and promient plaque formation in the external 
to the syptoms. For stable, die
caotid arery appropriate  , ischemic 
fid :; 
syptoms, areriography or duplex must  50% diameter reduction in the 
common or internal caotid arery bilateraly. For evolvg, foc, ischemic 
syptoms areriography or duplex must judge promient formation in the 
internal or common carotid artery, or areriogrphy must judge a large 
ulceratie lesion in the internal or common caotid arery. For acute stroke 
areriography or duplex imagig must fid promient plaque formation in the 
internal or common caotid artery and the procedure must be done shortly 
afer the onset of stroke. 
ASYMOMATIC STENOSIS: Areriography or duplex imagig must fid an 
atherosclerotic lesion in the common or internal caotid arery producing:; 75% 
diameter reduction, or areriography must 
fid a large multicentrc ulcerative 
atherosclerotic lesion in the common or internal caotid arery. 
STROKE: Stroke is defied as 
stroke in evolution (which refers to the neurological 
deficit manested hours or days afer the intial event) and acute stroke (which is a 
stroke of onl several hours duration). 
OTHR: A patient may undergo a carotid endaerectomy prior to or in conjunction
with another procedure for the purose of reducing the rik of further stroke. 
Misur 
SYMTOMATIC STENOSIS: 
TI 
Symptoms: The patient must have  or CV A symptoms. And: 
Imagig: Radiographic evidence must show:; 50% carotid occlusion 
(diameter), or 70% reduction in the cross-sectional area, or ulcerated plaque 
or embolic phenomenon. 
C - 14
 ASYMOMATIC STENOSIS: Asptomatic stenosis is not mentioned. 
STROKE: Stroke is defied as a 
CV 
OTHR: 
None. 
JJg 
MOI  d: 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have classica 
with hemiparesis, 
hemianesthesia, or dyphasia lasting oe 24 hour; or amaurosis fugax; or 
unateral neurologica deficits such as hemiparesis or hemianesthesia lasting 24 
hours to 7 days (RIN); or stroke. And: 
conf 
Imagig: Angiography including DSA must  an atherosclerotic lesion in 
the appropriate caotid artery. 
ASYMOMATIC STENOSIS: Areriogram must fid a 90% carotid lesion, or an 
80% carotid lesion with signcant ulceration; or brain CAT scan must fid a silent 
inarct with a 90% caotid lesion, or an 80% caotid lesion with ulceration. 
STROKE: Stroke is defied as a stroke lasting over one week with complete or 
nearly complete recovery of neurological fuction.

OTHR: 
None. 
Nebra 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have ipsilateral carotid terrtory syptoms 
includig contralateral weakess, clumsiness, paralis, contralateral numbness 
paresthesias includig loss of sensation, dysarthra, dysphasia, ipsilateral 
monocular blidness (amaurosis fugax), or contralateral homonymous 
hemianopia (defective vision affecting the right halves or left halves of the 
viual fields). And: 
Imagig: Angiogram or  75% unateral caotid 
duplex study demonstrates 
stenosis of the ipsilateral common or internal caotid  50% stenosis of 
artery, 
the common or internal caotid arery associated with contralateral internal 
caotid arery oclusion, or ulcerated atheromatous caotid bifrcation plaque 
with asociated  50%. 
stenosis of 
ASYMOMATIC STENOSIS: Asptomatic stenosis is not mentioned. 
C - 15
 STROKE: Stroke is not addressed. 
OTHR: 
None. 
Ham 
New 
SYMTOMATIC STENOSff: 
TI 
Symptoms: The patient must 
have clasica  with hemiparesis, 
hemianesthesia, or dysphasia lasting oe 24 hour; or amaurosis fugax; or 
unatera 
neurologica deficits such as hemiparesis or hemianesthesia lasting 24 
hour to 7 days (RI); CV A; or syptomatic caotid bruit. And: 
Imagig: Areriogrphy must fid a 90% caotid stenosis, or an 80% caotid 
sigIcat 
stenosis with  ulceration. Nonivasive caotid examation must
confed 
by areriography. 
ASYMOMATIC STENOSIS: Asptomatic stenosis is not mentioned. 
STROKE: Stroke is defied as a cerebrovascular accident lasting over one week with 
complete or parial recovery of neurologica function. 
OTH: 
None. 
Jer 
New 
SYMTOMATIC STENOSIS: 
TI 
Symptoms: The patient must have classica  with hemiparesis 
hemianesthesia, or dysphasia; or amaurosis fugax or stroke. And: 
conf 
Imagig: 
Angiography including DSA must  an atherosclerotic lesion in 
arery 
the appropriate caotid 
ASYMOMATIC  80% caotid stenosis 
STENOSIS: Areriogram must reveal 
(complex ulcerations with oe 80% stenosis require referral). 
STROKE: Stroke is defied as the patient havig complete or nearly complete 
recovery of neurological function. 
OTHR: 
None. 
C - 16
 Mer 
New 
SYMOMATIC STENOS 
flucttig 
Symptoms: The patient must have a mid or  neurological deficit 
with correspondence of syptoms/sign to the hemipheric distribution of the 
obstructed caotid arery. And: 
Imagig:  70% stenosis of the 
Angiography or DSA must demonstrate 
internal caotid artery, caotid bulb, or common caotid arery (or 50% with a 
large ulcer). 
ASYMOMATIC 
70% 
STENOSIS: Angiography or DSA must demonstrate 
stenosis of the internal caotid arery, caotid bulb, or common caotid arery. 
STROKE: Stroke is not addressed. 
OTHR: Unle other PRO criteria, New Mexico  determe 
lits the conditions that 
when the caotid endaerectomy is "usualy not indicated." Th surgica procedure is 
not indicated when there is c: 50% caotid stenosis without ulcerated plaque, or when 
a brai imagig procedure documents new, major inarction on the affected side. 
New York 
SYMOMATIC 
STENOSIS: 
TI 
Symptoms: The patient must have clasica  with hemiparesis 
hemianesthesia, or dysphasia; or amaurosis fugax or stroke. And: 
conf 
Imagig: Angiography includig DSA must  an atherosclerotic lesion in 
the appropriate carotid arery. 
ASYMOMATIC  80% caotid stenosis 
STENOSIS: Areriogram must reveal 
(complex ulcerations with c: 80% stenosis require referr). 
STROKE: Stroke is defined as the patient havig complete or nearly complete 
recovery of neurological function. 
OTHR: 
None. 
C - 17
 So 
Nor  Ca  d: 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have tranient speech dysfuncton, altered body
senstion, gait disturbance, dysahra; or 
amaurosis fugax or tranient 
hemiparesis; or stroke. And: 
Imagig: 
Angiography must demonstrate caotid  75%; or ulcerated 
stenosis 
plaque refractory to conservative medica management; or caotid aneurym, or
caotid dicton; or clica radiography must evidence a prior cerebral stroke 
asation 
in  with an ipsilateral caotid  75%. 
stenosis 
ASYMOMATIC STEOSIS: 
Angiography must demonstrate caotid 
stenosis 
75%. In addition, the medica record must include a consenting opinon from a non
afated 
second physician stating that the procedure is merited. 
STROKE: Stroke is defied as a stroke with complete or nearly complete recovery of 
neurologica function. 
OTHR: 
None. 
Nor Data 
SYMOMATIC 
STENOSIS: 
TI 
Symptoms: The patient must have classica  with hemiparesis 
hemianesthesia, or dysphasia lasting -c 24 hours; or amaurosis fugax; or 
uniateral neurologica deficits such as hemiparesis or hemianesthesia lasting 24 
hours to 7 days (RIN); or stroke. And: 
conf 
Imagig: 
Angiography including DSA must  an atherosclerotic lesion in 
the appropriate carotid artery. 
ASYMTOMATIC STENOSIS: Areriogram must fid a 90% caotid lesion, or an
80% caotid lesion with signcant ulceration; or brai CAT scan must fid a silent 
inarct with a 90% carotid lesion, or an 80% caotid lesion with ulceration. 
STROKE: Stroke is defied as a stroke lasting over one week with complete or 
nearly complete recovery of neurological function. 
OTHR: 
None. 
C - 18
 Ohi 
SYMTOMATIC STENOSIS: 
Symptoms: The patient must have cerebrovascul inuffciency syptoms (Le.
TI, 
amaurosis fugax sensory or motor monoparesis or hemiparesis)  And: 
Imagig: Angiogr DSA, or duplex imgig  50% 
must demonstrate 
uniateral cross-sectional stenosis of the common or internal  50% 
caotid, 
bilteral cross-sectonal stenosis, or complete ipsilteral internal caotid 
asiated 
occlusion  50% contralateral cross-sectional stenosis (only the 
with 
contralateral lesion should be considered for surgery), or a large ulcerated 
plaque. 
ASYMOMATIC STENOSIS: Angiogram, DSA, or duplex imagig must 
75% uniateral internal or common caotid 
demonstrate  cross-sectional stenosis, or 
50% stenosis in the presence of a contralateral internal or common carotid 
occlusion. 
STROKE: Stroke is defied as documented, ipsilateral stroke. 
OTHR: 
None. 
Oklma 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have amaurosis fugax (monocular or partial 
TI 
.c 10 miutes); or hemipheric 
blidness lastig  with the past 12 months; 
or hemipheric stroke. And: 
Imagig: 
50% stenosis and/or 
Angiography or DSA must document 
ulceration in an appropriate carotid artery (Le., the caotid 
supplying the 
cerebral hemiphere responsible for the symptoms). The percentage of stenosis 
must be specified. 
ASYMOMATIC STENOSIS:  75% 
Angiography or DSA must document 
stenosis, or lumen .c 2 mm in the common or internal caotid 
artery, or bilateral 
75% occlusion on the operative side. 
stenosis with 

STROKE: Stroke is descn"bed as hemispheric stroke with documented good recovery 
minimal to modest deficit. 
or with 

OTHR: 
None. 
C - 19
 ,. 
Orn 
SYMTOMATIC STENOS 
Symptoms: The patient must have amaurosis fuga hemipheric TI 
stroke. Or:

Imagig: The patient must have a hemodynamca signcat stenosis (50% 
diameter or 75% 
cross-sectional area), or an ulcerated plaque. 
ASYMOMATIC STENOSIS: The patient must have a hemodynamcally signcat
stenosis (50% diameter or 75% cross-sectional area). 
STROKE: Stroke is defied as hemispheric stroke with docmented good recovery
mial 
and with  to modest deficit. 
OTHR: 
None. 
Penlvan 
SYMOMATIC 
STENOSIS: 
TI 
Symptoms: The patient must have  (speech dysfucton, altered boy
senstion, gait diturbance, dysarhra, loss of motor cordiation of upper or 
lower extremity, hemiparesis, or uniparesis); or amaurosis fugax if ipsilateral to
lesion; or stroke. And: physical exaation must suggest a caotid bifrcation 
atheroma or embolition by a cervcal brut; neurological deficits; or 
oculopneumoplethysmography, doppler spectral frequency analysis, or duplex
scag 
evidencing a signcat caotid lesion; ulcerated plaque; or ,. 70% 
stenosis. And: 
Imagig: Angiography alone, or angiography and doppler spectral scanng (or 
scag),  conf 
duplex  must  70% diameter stenosis. 
ASYMOMATIC 
STENOSIS: Angiography must indicate;: 70% bifurcation 
stenosis and the patient has no major operative 
rik factors which contraidicate 
conf. 
surgery. If,. 70% stenosis on nonivasive studies, angiography must 
STROKE: Stroke is defied as a stroke with complete or nearly complete recovery of 
neurologica function. 
OTHR: 
None. 
C - 20
 Pu Ri 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have clasica  with hemiparesis, speech
dysfuction, altered boy sensations, gait 
diturbance, hemianesthesia, 
amurosis fugax or unateral neurologica 
dyphasia lastig'" 24 hour; or 
deficits such as hemiparesis or hemianesthesia lastig 24 hour to 7 
days 
exaation 
(RIN); or stroke. Physica  must fid caotid bruit, neurological 
plaques in the eye grounds. And: 
deficits or cholesterol 
conf 
Imagig: 
Angiography must  an atherosclerotic lesion in the 
appropriate caotid artery. 
ASYMOMATIC STENOSIS: Areriogram must fid a 90% caotid lesion, or an
80% caotid lesion with signcant ulceration; or brai CAT sca must fid a silent 
inarct with a 90% carotid lesion, or an 80% caotid lesion with ulceration. 
STROKE: Stroke is defied as a stroke lasting over one week with complete or 
nearly complete recovery of neurologica function. 
OTHR: 
None. 
Rh 
SYMOMATIC 
STENOSIS: 
Symptoms: The patient must have foc or neurological deficit (transient or 
permanent) compatible with caotid lesion. And: 
Imagig: Angiogram must demonstrte ulceration of the internal carotid arery 
compatible with the afected side whie on antiplatelet drugs. Brai cr sca 
must not reveal another lesion that could explai the symptoms. 
ASYMOMATIC STENOSIS: Asymptomatic stenosis is not mentioned. 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
Sout Dakta 
SYMOMATIC 
STENOSIS: 
Symptoms: The patient must have transient 
monocular blidness (amaurosis 
TI 
fugax) with ipsilateral caotid stenosis or plaque; or  (involvng the anterior 
C - 21
 circulation with face, ar, hand, or leg numbness or weakess; aphasia; or 
24-
dysphasia) for c:  hours and traceable to the appropriate caotid, or 
stroke. The medica record must document neurologica deficit. And: 
Imagig: Areriogram or DSA must show a hemodamcay signcat lesion 
defied as at least 60% diameter stenosis or 84% cross sectional area stenosis 
or ulceration. Hemipheric syptoms (tranient foc motor sensory or 
cr sc 
or MR. 
aphasias) require a 
ASYMOMATIC STENOSIS: Imagig must  60% diameter 
demonstrate stenosis 
or 84% cross-sectional area, or a severe, 
deep ulceratie plaque. 
STROKE: Stroke is defied as a recent CV A traceable to the 
exta-cranial carotid 
source where the patient made a fuctional recovery but would benefit from 
recurent 
protection agaist a  event. Additional stroke defitions include a stroke in 
progress or acute stroke with 6 hours followig caotid endarerectomy or trauma to 
the neck.

OTIR: 
None. 
Ten 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have classica 
with hemiparesis, 
hemianesthesia, or dysphasia lasting c: 24 hours; or amaurosis fugax (temporary 
loss of viion in one eye due to inufcient blood flow to the retina and lasting 
c: 10 miutes); or unateral neurological deficits such as hemiparesis or 
hemianesthesia lasting 24 hours to 7 days (RIN); or stroke. And: 
Imagig: Areriogram must fid  90% caotid  80% caotid 
lesion, or a 
lesion with significat ulceration; or brai sca must find a 90% carotid lesion 
or an 80% caotid lesion with ulceration. 
ASYMOMATIC STENOSIS: Imagig must  90% caotid lesion, a 80% 
fid a 
caotid lesion with signcant ulceration, silent  90% carotid lesion, or 
inarct with a 
80% caotid lesion with ulceration. 
silent inarct with a 
STROKE: Stroke is defied as a stroke lasting over one week with complete or 
nearly complete recovery of neurologica function. 
OTIR: 
None. 
C - 22
 Ter 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have defite  involvg the 
or stroke 
ipsilateral hemiphere or ipsilateral retial circultion. And: 
fid :: 
Imagig: Imagig must  50% stenosis of the caotid arery or an 
ulcerated plaque. 
ASYMOMATIC STENOSIS: Imagig must fid signcat stenosis (:: 90%) in the 
common or internal caotid arery, or stenosis :: 50% in the common or internal 
caotid arery with the presence of an ulcerated plaque. 
STROKE: Stroke is defied as a non-disblig stroke involvg the ipsilateral 
hemisphere or ipsilateral retial circulation. 
OTIR: 
None. 
Uta 
SYMOMATIC STENOSIS: 
TI 
Symptoms: The patient must have clasica  with hemiparesis 
hemianesthesia, or dysphasia lasting c: 24 hours; or amaurosis fugax (tranient 
loss of viion); or uniateral neurologica deficits such as hemiparesis or 
hemianesthesia lasting 24 hour to 7 days; or stroke. And: 
Imagig: 
Angiography, including four-vessel intra and extracranial direct 
conf 
signcat
arteriogram, must  the appropriate caotid lesion and lack of 
dita 
obstructive disease. 
ASYMOMATIC STENOSIS: Asptomatic stenosis is not mentioned. 
STROKE: Stroke is defied as a  one week with complete or 
stroke lastig over 
nearly complete recoery of neurologica function. 
OTIR: 
None. 
Vernt 
SYMOMATIC STENOSIS: 
TI (i. 
Symptoms: The patient must have clasica  , hemiparesis 
hemianesthesia, or dysphasia lasting c: 24 hours); or amaurosis fugax (transient 
C - 23  monocular blidness); or unateral neurologica deficits such as hemiparesis or 
(RI); 
hemianesthesia lastig 24 hours to 7 days  or stroke. And: 
Imagig:  70% stenosis in the appropriate caotid 
Angiography must fid 
arery. 
ASYMOMATIC STENOSIS: cr sca must fid silent inarct. Angiography must
fid at least 70% stenosis in appropriate caotid arery. 
STROKE: Stroke is defied as a stroke lastig over one week with complete or 
nealy complete recoery of neurologica fuction. 
OTHR: 
None. 
Vug 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have focal or global cerebrovascular insuffciency 
syptoms or sigI including amaurosis fugax (temporar, reversible loss of 
viion), unateral tranient tinglg in 
libs or face (paresthesias), paresis
paralis  TI foc 
diplopia (double viion), vertgo,  neurologica deficit that 
resolves in oe one hour, stroke, sycope, gait diturbance  dyhra, tranient 
speech dyfuction, or altered body senstions. And: 
Imagig: 
Angiography must evidence;: 50% plaque stenosis of common or 
internal caotid arery; or plaque necrosis or ulceration (e.g., 
actiely embolic); 
or a totay occluded internal caotid arery with;: 70% stenosis in the external 
caotid arery. 
ASYMOMATIC STENOSIS: Angiography must evidence ;: 80% plaque stenosis. 
STROKE: Stroke is defied as a completed stroke over 6 weeks old or fewer than 18 
months old. 
OTHR: 
None. 
Vug Isla

SYMOMATIC 
STENOSIS: 
Symptoms: The patient must have cerebral vascular insuffciency syptoms.
And: 
Imagig: Angiogram must demonstrate: ;: 50% uniateral stenosis of the 
common or internal carotid, or ;: 50% bilateral stenosis, or internal carotid 
C - 24  occlusion associated with;: 50% contralateral stenosis or an ulcerated 
atheromatous plaque. 
ASYMTOMATIC STENOSIS: Angiogram must demonstrte;: 70% uniateral 
internal or common caotid stenosis, or ;: 50% stenosis in the presence of a 
contralateral internal or common caotid  oclusion. 
(occlusion), or total 
STROKE: Stroke is not addressed. 
OTHR: 
None. 
WlS 
SYMOMATIC STENOSIS: 
Symptoms: The patient must have TI, or amaurosis fugax or RIN (e.g. 
tinglg libs, face paresthesias, paresis, or paralysis), or nonhemispheric 
syptoms (e.g., vertgo, syncope). The syptoms must be consistent with the 
lesion location. And: 
conf 
Imagig: Angiogram must  caotid stenosis ;: 70% or an ulcerated 
atheromatous plaque. 
ASYMOMATIC STENOSIS: Angiogr must demonstrte;: 70% stenosis; and 
caotid duplex sca must document bloo velocty ;: 1.5 m.sec, or peak sytolic 
frequency ;: 12 kiohert or 
reversed periorbita flow. 
STROKE: A physician advior must review the patient s stroke (CV A) hitory. 
OTHR: 
None. 
C - 25