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www.icvts.org

doi:10.1510/icvts.2009.231878

Interactive CardioVascular and Thoracic Surgery 11 (2010) 182–184

� 2010 Published by European Association for Cardio-Thoracic Surgery

Brief communication - Carotid and imaging

Postoperative internal carotid artery restenosis after localanesthesia: presence of risk factors versus intraoperative shunt

Narcis Hudorovic *, Ivo Lovricevic , Hrvoje Hajnic , Zaky Ahela, a b c

Department of Vascular Surgery, University Hospital ‘Sestre Milosrdnice’, Vinogradska 29, 10000 Zagreb, Croatiaa

Department of Psychology and Human Resources Management, Koncern ‘AGRAM’, Zagreb, Croatiab

‘Dr. Zaky Polyclinic’, Policlinic for Internal Medicine and Urology, Zagreb, Croatiac

Received 28 December 2009; received in revised form 11 April 2010; accepted 13 April 2010

Abstract

Published data suggest that the regional anesthetic technique used for carotid endarterectomy (CEA) increases the systolic arterial bloodpressure and heart rate. At the same time local anesthesia reduced the shunt insertion rate. This study aimed to analyze risk factors andischemic symptomatology in patients with postoperative internal carotid artery restenosis. The current retrospective study was undertakento assess the results of CEA in 8000 patients who were operated during a five-year period in six regional cardiovascular centers. Carotidcolor coded flow imaging, medical history, clinical findings and atherosclerotic risk factors were analyzed. Among them, there were 33patients (0.4%) with postoperative re-occlusion after CEA. The patients with restenosis were re-examined with carotid color coded flowimaging and data were compared with 33 consecutive patients with satisfactory postoperative findings to serve as a control group. In therestenosis group eight risk factors were analyzed (hypertension, smoking, hyperlipidemia, diabetes mellitus, history of stroke, transitoryischemic attack, heart attack and coronary disease), and compared with risk factors in control group. Study results suggested that earlypostoperative internal carotid artery restenosis was not caused by atherosclerosis risk factors but by intraoperative shunt usage.� 2010 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.

Keywords: Carotid endarterectomy; Local anesthesia; Risk factors; Complications

1. Introduction

Indications for carotid endarterectomy (CEA) were wellestablished from four level 1A clinical trials; the NorthAmerican Symptomatic Carotid Endarterectomy Trial (NAS-CET) w1x, the European Carotid Surgery Trial (ECST) w2x, theAsymptomatic Carotid Atherosclerosis Study (ACAS) w3x, andthe Asymptomatic Carotid Surgery Trial (ACTS) w4x.

Patients who undergo CEA in these study use resources asrecommended by the AHA guidelines for CEA w5x. Currently,reliable data for defining an acceptable duration and inten-sity of postoperative monitoring are lacking w6x. Therefore,the Croatian Society for Neurovascular Disorders took anactive part in the implementation of new concepts of strokemanagement and treatment to provide updated recommen-dations that can be used on adopting new treatmenttherapeutic methods and procedures. In this study, westrictly followed the mentioned rules which state that thefirst postoperative outpatient neurosonological control isrecommended three months after CEA w7x. ICA restenosisusually develops early, within two years after surgery. Ifrestenosis develops after a longer period of time, it isusually caused by well-established atherosclerosis risk fac-tors that caused the original disease. The aim of this studywas to analyze the risk factors, intraoperative usage of the

*Corresponding author. Tel.: q385-1-4640-774; fax: q385-1-3787-290.E-mail address: narcis.hudorovic@zg.htnet.hr (N. Hudorovic).

shunt and ischemic symptomatology in patients with post-operative ICA restenosis.

2. Method

We retrospectively examined records of 8000 patients whounderwent local anesthesia carotid endarterectomy (LA-CEA) in six regional cardiovascular departments during afive-year period. According to postoperative computedtomography angiography (CTA) and carotid color flow imag-ing (CCDFI) data, there were 33 (0.4%) patients with ICArestenosis in this group. There was a predominance of malepatients (75.7%), and mean age was 68.7 (age range 50–85) years. A standard open LA-CEA was performed in allpatients. A shunt was inserted if there was deterioration inthe level of consciousness. Patch closure with a polytetra-fluoroethylene (PTFE) patch material was undertaken in allstudy patients. Neurological events were classified as minorwtransient ischemic attacks (TIA)x and major neurologicaldeficits. Major neurological deficits were defined as thosedeficits that lasted beyond seven days. We confirmedintraoperative abnormal focal neurological signs by anelectroencephalogram andyor prolonged electroencepha-lographic monitoring. All the patients with ICA restenosiswere re-examined with CCDFI. Data on 33 consecutivepatients with a satisfactory CTA and CCDFI postoperativefindings were analyzed to serve as a control group. All

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Table 1. Patient characteristics according postoperative restenosis and con-trol group

Patients Postoperative Satisfactoryrestenosis postoperative finding(ns33) (ns33)

Gender 25 malesy8 females 23 malesy10 femalesAge (years; mean"S.D.) 68.7"7.2 70.7"7.2Age at time of surgery (years) 65.6 65.8Median postoperative 3.8 4.4follow-up (years)Side of CEA 18 righty15 left 21 righty12 left

S.D., standard deviation; CEA, carotid endarterectomy.

Table 2. Influence of eight risk factors for restenosis

Risk factors Patients x -test2 Binary logistic regression

Postoperative Satisfactory postoperative x2 P-value B df P-valuerestenosis finding

Hypertension 18 18 0.000 1.00 1.117 1 0.47Smoking 11 10 0.070 0.79 2.826 1 0.02Hyperlipidemia 13 8 1.746 0.19 3.531 1 0.05Diabetes melitus 7 9 0.330 0.57 –0.195 1 0.93Previous stroke 7 13 2.583 0.11 3.023 1 0.02Previous TIA 3 3 0.000 1.00 –0.748 1 0.71Previous IM 4 4 0.000 1.00 1.201 1 0.50Operative shunt 25 3 30.023 0.00 7.653 1 0.00All 33 33

x -test was used to examine differences between two groups of patients.2

Binary logistic regression was used to examine which risk factors are significant predictors for restenosis.P-value, statistical significance; B, estimate; df, degrees of freedom; TIA, transient ischemic attacks.

follow-up CCDFI examinations (restenosisycontrol group)were conducted by the same investigator using the sameequipment (ALOKA 5500, 10-MHz linear probe).x2-test was used to examine differences between two

groups of patients considering eight risk factors. Binarylogistic regression analysis (dichotomous variable) was usedto examine which risk factor is the most significant predic-tor for restenosis. All analyses were carried out using theSPSS 16.0.1 software package (SPSS Inc, Chicago, IL, USA).

3. Results

The patient demographic data are shown in Table 1.Significant postoperative ICA restenosis (25 patientsy75%)

was recorded in 11 patients on the left side and in 14patients on the right side. Combined occlusion of thecommon carotid artery and ICA occurred in eight (24%)patients, four on either side. Contralateral ICA showed non-significant atherosclerotic changes in 27 (82%) patients, ofwhich eight had undergone previous CEA. Twenty-four (72%)patients had moderate ICA restenosis and one (3%) patienthad subtotal ICA restenosis. CCDFI demonstrated ICA res-tenosis on the first follow-up examination taken threemonths after the CEA in 31 (94%) patients, and during thefirst- and third-year of follow-up in one (3%) patient each.Three (9%) patients presented with ischemic symptomsduring the first postoperative days (TIA in two patients andstroke in one patient). In the group with satisfactorypostoperative finding, 17 patients had CEA on the rightside, 12 on the left, and four patients had bilateral CEA.Contralaterally, 25 (76%) patients had non-significant ath-

erosclerotic changes, six (18%) patients developed mild ICArestenosis, and two (6%) patients had occlusion of thecontralateral ICA.

The presence of atherosclerotic risk factors (hypertension,smoking, hyperlipidemia, diabetes mellitus, history of TIAystroke, history of myocardial infarction and coronary dis-ease), and usage of intraoperative shunt were analyzed inboth groups of patients. The results are presented inTable 2.

Statistically significant difference between two groupswas found in the ‘operative shunt’ risk factor (x s30.023,2

Ps0.00).Our results suggest that the significant predictors for

restonosis are: operative shunt (Bs7.653; Ps0.00), smok-ing (Bs2.826; Ps0.02), previous stroke (Bs3.023;Ps0.02) and hyperlipidemia (Bs3.531; Ps0.05).

4. Discussion

Recognized risk factors for developing early postoperativeICA occlusionyrestenosis were smoking, smaller diameter ofICA, defects found during surgery, and certain genotypesw8x.

However, systemic risk factors, such as hypertension,hyperlipidemia, and obesity increase the risk of developinglate postoperative ICA occlusionyrestenosis (two years ormore after CEA). Diabetes mellitus and age over 80 yearshave been established as risk factors for developing latepostoperative ICA occlusionyrestenosis as well as being apredictive factor for the increased risk of perioperativestroke or death (30 days after CEA) w8x.

In our study atherosclerotic risk factors were present in ahigh percentage of the postoperative ICA occlusionyresten-osis group but there was no significant difference from thecontrol group.

According to the recent literature the incidence of brainischemic symptoms in postoperative ICA restenosis variesbetween 1% and 4% w8, 9, 10x. In our series, three of 33patients with postoperative ICA restenosis presented withischemic symptoms (one stroke; two TIA), and moderateICA restenosis of the contralateral ICA was found in six of33 (18%) patients and contralateral ICA occlusion in two(6%) patients. To remove atheromatous plaque, surgeonsmust clamp the ICA. A shunt can be inserted to avoid brain

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ischemia during clamping, but the shunt itself might dis-lodge a part of the plaque or damage the residual intimaof the vessel, thus favoring postoperative restenosis. Ourresults suggest that postoperative ICA restenosis after LA-CEA is rare and mostly asymptomatic, and it is predomi-nantly caused by intraoperative usage of a shunt (localshunt-microtrauma).

With road-mapping it is possible to superimpose livefluoroscopy on a radiographic image. A refurbished oper-ating room with a fluoroscopy unit for intraoperative angio-graphic control will be of benefit to both patients and theoperating team. Unfortunately, superior imaging, decreas-ing radiation and optimal ergonomics are still a barrier forvascular institutions in which this study was performed.Obviously, the realization of such an operating suite isessential for improving the every-day work in vascularcenters.

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