Outcome of Carotid Endarterectomy in a Tertiary Center of Nepal: A Retrospective Study

Abstract

Introduction Carotid endarterectomy for carotid artery disease is one of the surgeries performed by vascular surgeons for carotid artery disease. The objective of this study is to describe the early and late outcome of the patient undergoing carotid endarterectomy and the association between the complication and comorbidities present previously in the patient. Methods
All patients undergoing carotid endarterectomy at Manmohan Cardiothoracic Vascular and Transplant Centre between April 2010 to April 2020 were included. The follow-up data for upto a year from medical and clinical records, telephone interview regarding the immediate and late postoperative complications in patients with and without comorbidities were investigated and compared. ResultsThe total study population was 42 patients. Two patients (4.7%) developed stroke, one immediately in postoperative period and the other during follow up. There were two deaths (4.7%) postoperatively due to cardiac events and three (7.14%) recurrences of carotid stenosis among whom one (2.5%) developed late stroke. Twenty six patients (61.90%) were symptomatic prior to the procedure of which 20 patients (47.61%) had brain infarct. Overall one year survival was 95.2% post procedure and overall complication rate was 7.14%. The consequence in the form of death and stroke occurred more in the patients with comorbidities (3vs1) p=0.42. Conclusion
The immediate and late postoperative complications following carotid endarterectomy were death (4.7%), stroke (4.7%), cranial nerve injury (9.5%). The most frequent cause of death was postoperative cardiac event. Though major complications occurred more frequently in patients having comorbidities, it was statistically insignificant.

Full text

31
ABSTRACT
Introduction
Carotid endarterectomy for carotid artery disease is one of the
surgeries performed by vascular surgeons for carotid artery disease.
The objective of this study is to describe the early and late outcome of
the patient undergoing carotid endarterectomy and the association
between the complication and comorbidities present previously in
the patient.
Methods
All patients undergoing carotid endarterectomy at Manmohan
Cardiothoracic Vascular and Transplant Centre between April 2010
to April 2020 were included. The follow-up data for upto a year from
medical and clinical records, telephone interview regarding the
immediate and late postoperative complications in patients with
and without comorbidities were investigated and compared.
Results
The total study population was 42 patients. Two patients (4.7%)
developed stroke, one immediately in postoperative period and the
other during follow up. There were two deaths (4.7%) postoperatively
due to cardiac events and three (7.14%) recurrences of carotid
stenosis among whom one (2.5%) developed late stroke. Twenty six
patients (61.90%) were symptomatic prior to the procedure of which
20 patients (47.61%) had brain infarct. Overall one year survival was
95.2% post procedure and overall complication rate was 7.14%. The
consequence in the form of death and stroke occurred more in the
patients with comorbidities (3vs1) p=0.42.
Conclusion
The immediate and late postoperative complications following
carotid endarterectomy were death (4.7%), stroke (4.7%), cranial
nerve injury (9.5%). The most frequent cause of death was
postoperative cardiac event. Though major complications occurred
more frequently in patients having comorbidities, it was statistically
insignicant.
Keywords
Carotid artery, cerebrovascular disease, endarterectomy
Original Article
JIOM Nepal. 2021 Apr;43(1):31-35.
Outcome of Carotid Endarterectomy in a Tertiary Center of Nepal:
A Retrospective Study
Prashiddha B Kadel, Uttam K Shrestha, Kajan R Shrestha, Dinesh Gurung
Author(s) aliation
Department of Cardiothoracic and
Vascular Surgery, Maharajgunj
Medical Campus, Manmohan
Cardiothoracic and Vascular
Transplant Center, Institute of
Medicine, Maharajgunj, Kathmandu,
Nepal
Corresponding author
Prashiddha B Kadel, MBBS, MS
prashiddhakadel@gmail.com
Journal of Institute of Medicine Nepal
Institute of Medicine, Kathmandu, Nepal
Submitted
Dec 2, 2020
Accepted
Mar 18, 2021
© JIOM Nepal

32
INTRODUCTION
Carotid artery disease as a disease entity is
known since the start of civilization. In 1658,
Wepfer highlighted the association of right
sided hemiplegia with occlusion of left internal
artery with inference of carotid artery disease and
hemiplegia. In 1665, Willis described a case with
asymptomatic carotid artery stenosis.1 During 20th
century, there was a concept that carotid artery
bifurcation stenosis could lead to stroke due to
clot embolism but the characteristics of stenosing
lesion and the type of plaque causing embolism
was described only after 50 years.2
The first surgery which decreased the incidence
of stroke and other complications related to the
atheroma was carotid endarterectomy and it was
performed in women presenting with amaurosis
fugax resulting in successful treatment.2,3
The European Carotid Surgery Trial proposed that
in symptomatic patients, carotid endarterectomy
provided improved stroke free interval in patients
having greater than 70 percent stenosis.4 Similarly,
the North American Symptomatic Carotid Trial also
proposed that either symptomatic or asymptomatic
patients with 70 percent or more stenosis, more
benefitted from surgery with proportion of stenosis
related to outcome of surgery.5 The Veterans
Administration Asymptomatic Trial entails that
symptomatic patients with history of frequent
transient ischemic attacks or small cerebral
infarction had favourable outcome after surgery as
compared to medical therapy.6 The Asymptomatic
Carotid Atherosclerosis Study showed that patients
with 60% or more stenosis were candidate for
carotid endarterectomy and had a lower risk of
stroke at 5 years as compared to medical therapy.7
The main advantage of surgery is the high rate of
freedom from stroke though there is associated
risk of surgical complications. However, with the
advent of refinement of surgical techniques and
intrra operative monitoring, the complication rate
has decreased significantly over the years.8
The objective of this study was to describe the
early and late outcomes of patients that underwent
carotid endarterectomy and study the association
between complications and comorbidities present
previously in the patient.
METHODS
This is a retrospective study conducted at
Manmohan Cardiothoracic Vascular and Transplant
Centre, Kathmandu, Nepal using medical
records and telephone interview of the patients
undergoing carotid endarterectomy in Manmohan
Cardiothoracic Vascular and Transplant Centre. A
total of 42 patients with carotid artery stenosis were
enrolled in this study. The patients were referred
by either physicians, cardiologist, neurologist and
vascular surgeons. Comorbidities like hypertension,
diabetes mellitus, chronic obstructive pulmonary
disease (COPD), asthma were considered as
variables in the study. Both symptomatic and
asymtomatic patients with ≥70 percent carotid
artery stenosis on the basis of carotid Doppler
ultrasound, underwent carotid angiography for
proper delineation of anatomy of carotid vessels.
There was slight difference in extend of stenosis
observed between carotid Doppler ultrasound and
carotid angiography. With stenosis of ≥70 percent
found on coronary angiography, both symptomatic
and asymptomatic patients underwent carotid
endarterectomy after proper evaluation of cardiac
function and other baseline investigations. All
baseline investigations were sent preoperatively
and then surgery was planned and performed.
Any complications after surgery were noted.
Postoperatively, all patients were started on oral
antiplatelet therapy (dual antiplatelet therapy). All
patients were then followed up in the OPD or via
telephone. Patients with stroke or hemiparesis
were then followed up with CT scan or MRI head
and the size of infarct were noted and neurology
consultation was done. Any death or loss to follow
up were noted. All patients undergoing carotid
endarterectomy underwent CT angiography
postoperatively after 10-11 months if carotid artery
duplex showed greater than 50% stenosis of
operated carotid artery.
Carotid artery duplex scan was routinely carried
out 6 months after surgery. Stenosis of more than
50% after initial surgery was marked as recurrence
and interventions in the form of repeat carotid
endarterectomy or carotid artery stenting was
advised.
Fisher's Exact Test was applied at a significance
level of 5%. Survival rate was made according to
the actuarial method. The SPSS program version
25 was used for the construction of tables and
evaluation of data.
RESULTS
A total of 42 patients with carotid artery stenosis
underwent carotid endarterectomy and the
outcome was studied. In our study, there were 16
patients ≤ 60 years while 26 patients > 60 years with
mean age of 64.3±18.7 years. A total of 10 patients
(23.8%) were female and 32 patients(76.2%) were
male. In all, 57.1% had comorbidities of which 10
patients (23.8%) had diabetes mellitus, 8 patients
(19%) had both hypertension and diabetes,6
patients(14.3%) had only hypertension. Unilateral
stenosis was present in 85.7% whereas 14.3% had
bilateral disease at presentation. Sixteen patients
had concomitant disease in the form of coronary
artery disease or peripheral vascular disease of
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Kadel et al.
VOLUME 43 | NUMBER 1 | APRIL 2021

33
which 12 patients (28.57%) were diagnosed to
have significant carotid artery disease after routine
investigation of carotid artery using Doppler
ultrasound as a part of coronary artery bypass graft
preoperative investigation, whereas 4 patients
(9.5%) undergoing femoropopliteal or aortofemoral
bypass had their carotid artery disease diagnosed
while performing carotid doppler as a preoperative
investigation. All patients having peripheral vascular
disease underwent femoropopliteal or aortofemoral
bypass after treatment of carotid artery stenosis.
Twenty six patients (61.9%) were symptomatic
(previous stroke, transient ischemic attack or
amaurosis fugax (Table 1) whereas 16 patients
(38.1%) were asymptomatic in the form of no prior
history of previous stroke, transient ischemic attack
or amaurosis fugax. Carotid endarterectomy with
great saphenous vein patch closure was done in
22 cases (52%) which was on the discretion of the
surgeon .
Complications encountered during and after
carotid endarterectomy have been shown in table
2. Massive bleeding requiring cell salvage support
autotransfusion was seen in 2 cases (4.7%) and 1
patient had stroke in the immediate postoperative
period. There were 2 deaths (4.7%) in the post
operative period, the cause of death being cardiac
event, 4 patients (9.5%) had cranial nerve injury
(hypoglossal nerve being the most common) in the
immediate postoperative period which recovered
with time. Postoperative hypertensive crisis
occured in 4 cases (9.5%). Late stroke occurred in 1
patient during 1 year follow up. Three patients had
recurrence of the disease in the form of re-stenosis
of more than 50%, these patients were offered for
redo endarterectomy but they refused, 2 patients
underwent carotid artery stenting as an alternative
JIOM Nepal
Outcome of Carotid Endarterectomy
VOLUME 43 | NUMBER 1 | APRIL 2021
Table 3. Distribution of postoperative death and stroke by age, sex, stump pressure,
comorbidities and after the use of shunt in the patients undergoing carotid endarterectomy
Characteristics Death or stroke Total p-value
No Yes
Age
≤60 yrs
>60 yrs
Sex
Male
Female
Comorbidities (HTN/DM)
Yes
No
Symptoms
Ye s
No
Carotid stump pressure
>50mmhg
<50mmhg
Shunt
Yes
No
16 (38%)
22 (52.5%)
28 (66.6%)
10 (23.8%)
21 (50%)
17 (40.5%)
24 (57.2%)
14 (33.33%)
32 (76.2%)
6 (14.2)
2 (4.7%)
36 (85.7%)
0
4 (9.5%)
4 (9.5%)
0
3 (7%)
1 (2.4%)
2 (4.7%)
2 (4.7%)
2 (4.7%)
2 (4.7%)
2 (4.7%)
2 (4.7%)
16 (38%)
26 (62%)
32 (76.2%)
10 (23.8%)
24 (57.2%)
18 (42.8%)
26 (61.9%)
16 (38.1%)
34 (80.9)
8 (19.1%)
4 (9.5%)
38 (90.5%)
0.13
0.32
0.42
0.49
0.16
0.12
Table 1. Dierent symptoms of
carotid artery disease
Symptoms Number
Stroke within 6 months
Transient ischemic attack
Amaurosis fugax
20
4
2
Table 2. Dierent complications encountered
after carotid endarterectomy
Complications Number
Massive bleeding
Early stroke
Death in post-operative period
Cranial nerve injury
Hypertensive crisis
Late stroke
Recurrence
2
1
2
4
4
1
3

34
to surgery. Table 3 compares the distribution of
death or stroke as a consequence of surgery on the
basis of age, sex, stump pressure, comorbidities and
use or disuse of shunt in the patients undergoing
carotid endarterectomy. The difference in outcome
in terms of stroke or death were not statistically
significant between the groups based on age, sex,
stump pressure, comorbidities and use of shunt as
shown in table 3.
DISCUSSION
Carotid endarterectomy though considered a
relatively safe surgery is associated with early and
late complications.9 The cut-off of carotid artery
stenosis was kept at 70 percent and included
both symptomatic and asymptomatic population.
Different multicentric trials signify that patients
having 70% stenosis or more should be operated.
Asymptomatic Carotid Atherosclerosis Studystates
that all patients withstanding surgery with stenosis
of greater than 60% should be operated5,10, in the
end it all depends on the discretion of surgeons
whether to operate or not at around 60% stenosis
with symptoms and should be judged on case to
case basis.
Carotid artery disease is a part of multisystem
disease with peripheral artery disease, coronary
artery disease. According to this study, peripheral
artery disease was found in 4 cases (9.5%) and
12 cases (28%) had coronary artery disease.
Similar to the study done by Yan Wu et al which
showed that carotid atherosclerosis was an
independent risk factor for coronary heart disease
[OR = 2.66, 95% confidence interval (95% CI), 2.05–
3.46, p <0 .001].11 Klop et al in their study showed
that carotid artery disease with ≥75% stenosis
were present in 62 patients(14.9%) with peripheral
artery disease signifying the fact that carotid artery
screening should always be considered in a patient
of peripheral artery disease.12
In this study, wide range of patients with age
ranging from 45 to 86 years age with mean age of
64.31±8.7 years underwent carotid endarterectomy
with no significant difference in complications
related to different age group. Here we compared
between patients of age ≤ 60 years and > 60 years
(n=16 vs 26) or (38% vs 62%), though patients of
age less than 60years had more bleeding (2vs1), the
major adverse complications were more common
in age group more than 60 years with death in 2
patients (4.5%),postoperative hypertensive crisis
in 4 patients (all occurring in patients with age
greater than 60yrs),cranial nerve injury in 4 patients
(age greater than 60yrs). However it was found to
be statistically insignificant (p=0.66). There were 2
cases of stroke with 1 in immediate postoperative
period and another late stroke in patients, both
occurred in the patients with age >60 years
(p=0.134) which is similar to the study done by
Jeong MJ et al which concluded that age is an
independent risk factor for major adverse events
following CEA within 4 years.13 Summarizing, major
complications occurred more frequently in the age
group ≥60 years.
After carotid Doppler study, all patients under went
CT angiogram (CTA) of the carotid vessels for
proper delineation of the extent of stenosis and
feasibility of the surgery. In a study done by Titi M
et al, comparison of Doppler ultrasound and CT
angiography in evaluation of carotid stenosis they
found that the decision of operative management
changed in 28/187 cases (16%) (95% CI 0.11-0.21)
on the basis of carotid angiography.14
In cases of bilateral carotid artery stenosis, some
surgeons take a gap of at least 15 days between
the sequential surgery. In this study, sequential
surgery of the bilateral carotid artery was not done
though 4 patients had bilateral disease. Primary
endarterectomy was performed on the artery
with more severe stenosis or that associated with
symptoms, the latter artery with less significant
stenosis was to be operated only after 2-3 weeks.
However these patients opted for carotid artery
stenting after primary endarterectomy.
Carotid artery shunt is commonly done in our
institute if the stump pressure is below 50mmHg
which has been found to decrease post operative
stroke. In our study, carotid shunt was used
in 4 patients (9.5%), among whom 2 patients
developed major complication (stroke or death). In
38 patients (90.47%) where shunt was not required
intraoperatively, 2 patients had stroke or death
concluding that 50% patient undergoing carotid
endarterectomy using shunt had major complication
whereas 5.2% patient with stump pressure greater
than 50 mm Hg where shunt was not required
had adverse complications in the form of death or
stroke.However, it was not found to be significant
statistically (p=0.12).In a study done by Kwaan et al
in evaluation of stump pressure as a guide during
carotid endarterectomy, the study concluded that
carotid shunt doesnot ensure cerebral perfusion
rather the wakefulness during surgery serves to
prevent stroke when surgery is performed under
local anesthesia.15
Patients with hypertension and diabetes as
comorbidities had more postoperative stroke and
death as compared to patients without comorbidities
(n=3 Vs n=1) p=0.42. Similarly, patients with
comorbidities had more postoperative hospital stay
(5.25 days VS 5.22 days). Summarizing, patient with
comorbidities had higher frequency of complication
as compared to patients without comorbidities
though statistically insignificant. In a research done
by Jeong et al, the outcomes between diabetics
and nondiabetics were compared, and discovered
Kadel et al.
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35
that diabetics were at greater risk of late major
adverse event and identified diabetes as an
independent risk factor for occurrence of stroke.16
In the present study major complications occurred
more frequently in patients with comorbidities. The
overall complication rate in the study is 7% which
is slightly more than the criteria set by Guidelines
for carotid endarterectomy of the Special Writing
Group of the Stroke Council and American Heart
Association which has 6% of postoperative stroke
and death, if one has to demonstrate its superiority
as compared to medically treated symptomatic
carotid stenosis patient.5,7 The slight increase in
postoperative stroke and death might be due
to the involvement of both symptomatic and
asymptomatic patients with carotid artery stenosis.
In this study, the incision used was a longitudinal
which spares the greater auricular nerve in
comparison to the transverse incision. Following
surgery cranial nerve injury (unilateral hypoglossal
nerve, recurrent laryngeal nerve) was present in
4 patients (9.5%) and the most common cranial
nerve injury was hypoglossal nerve followed by
recurrent laryngeal nerve however the cranial nerve
deficit recovered over months and there was no
residual deficit which is similar to the study done by
Cunningham which showed that the most common
cranial nerve injury was hypoglossal (27) followed by,
recurrent laryngeal(17) and emphasized that the risk
of nerve injury persisting beyond hospital discharge
was around 4% after carotid endarterectomy (95%
CI 2.9–4.7) which decreased with increasing
experience.17
After completion of endarterectomy, patch closure
technique was used whenever surgeons felt the
caliber of artery small, 22 patients (52%) had
patch closure out of which 2 patients (9.09%)
had recurrence (p=0.53). While the study done by
Clagett demonstrated the routine saphenous vein
patch closure did not yield superior results and
was also found to have a greater incidence of early
recurrence( 12.9% vs 1.7% with p<0.05) and post
operative time however if anatomical risk factors
was present for recurrent disease saphenous vein
patch closure seemed to be appropriate.18
Focussing on the long term complication, one
patient had a stroke with debilitation with overall
survival in our study being 95.2% at one year.
CONCLUSION
The immediate and late postoperative complication
following carotid endarterectomy was death (4.7%),
stroke (4.7%), cranial nerve injury (9.5%). The most
frequent cause of death was postoperative cardiac
events.Though major complications occurred more
frequently in patients having comorbidities, it was
statistically insignificant.
CONFLICT OF INTEREST
None declared.
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Outcome of Carotid Endarterectomy
JIOM Nepal VOLUME 43 | NUMBER 1 | APRIL 2021