- Email: [email protected]
Duplex ultrasound surveillance after carotid artery endarterectomy
Duplex ultrasound surveillance after carotid artery endarterectomy Julien Al Shakarchi, MBChB,a,b Danielle Lowry, MBChB,b Jay Nath, MBChB,a Aurangzaib Z. Khawaja, MD,a Nicholas Inston, PhD,a and Alok Tiwari, MS,b Birmingham, United Kingdom Objective: After carotid endarterectomy (CEA), patients have been regularly followed up by duplex ultrasound imaging. However, the evidence for long-term follow-up is not clear, especially if the results from an early duplex scan are normal. This study assessed and systematically reviewed the evidence base for long-term surveillance after CEA and a normal early scan. Methods: Electronic databases were searched for studies assessing duplex surveillance after CEA in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome for this study was the incidence of restenosis after a normal early scan. The secondary outcome was the number of reinterventions after a normal early scan. Results: The review included seven studies that reported 2317 procedures. Of those patients with a normal early scan, 2.8% (95% confidence interval, 0.7%-6%) developed a restenosis, and 0.4% (95% confidence interval, 0%-0.9%) underwent a reintervention for their restenosis during the follow-up period. Conclusions: This review confirms that routine postoperative duplex ultrasound surveillance after CEA is not necessary if the early duplex scan is normal. (J Vasc Surg 2016;-:1-4.)
Patients have traditionally been regularly followed up by duplex ultrasound (DUS) imaging after carotid endarterectomy (CEA). The rationale for surveillance is that disease progression on the contralateral side and postintervention restenosis can reliably be detected, providing an opportunity for timely intervention to reduce the risk of stroke in asymptomatic patients. DUS accurately visualizes the carotid bifurcation and allows development of restenosis in the operated-on carotid artery and progression of disease in the contralateral carotid artery to be assessed.1 Nonrandomized studies have reported mixed results regarding the timing and value of postoperative DUS surveillance, but no consensus has been reached.2,3 Significant restenoses is generally thought to occur within the first 3 months after CEA and is the rationale most centers use to perform an early DUS scan.4 Restenosis has been shown to be more common after primary closure, and patch CEA has become the procedure of choice.5 Although there is good evidence that patch CEA reduces the rate of restenosis compared with primary closure, the clinical relevance of radiologically defined restenosis after patch CEA is not clear. Indeed, some authors believe that such stenoses have a low probability of future From the Department of Renal Surgerya and Department of Vascular Surgery,b University Hospital Birmingham. Author conflict of interest: none. Correspondence: Julien Al Shakarchi, MBChB, Department of Renal and Vascular Surgery, University Hospital Birmingham, Birmingham, B15 2TH, UK (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.01.054
neurologic events and that intervention is not warranted for such patients.6,7 Therefore, in view of this and advancements in medical management, one should question the value of performing routine carotid DUS scanning after surgery. The purpose of this study was to assess and systematically review the evidence basis for long-term surveillance after CEA and an early DUS with a normal result. Early DUS was defined as #3 months after surgery. METHODS Search methodology for identification of relevant studies. Searches of PubMed Central, MEDLINE, and the Cochrane Library were performed using combinations of the search terms carotid endarterectomy or carotid surgery with ultrasound, ultrasonography, duplex or Doppler, and timing or follow-up or surveillance or postoperative, to identify articles published between January 1, 1990, and October 31, 2015, in the English language. This date limit was set because patch CEA became a more routine and common procedure in the 1990s. The references cited in selected articles were reviewed for any further relevant available studies. Articles that assessed other imaging techniques were excluded. We included published randomized trials and observational studies. We excluded abstracts, case reports, review articles, editorials without original data, and non-English publications. Gray literature was not searched or included. The systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.8 Therefore, all included studies were assessed for inclusion on the basis of their topic, type of study, method, number of patients included, and availability of their original results. Primary and secondary outcomes. All studies that met the above set criteria were reviewed and assessed for 1
JOURNAL OF VASCULAR SURGERY --- 2016
2 Al Shakarchi et al
Fig. Flow chart shows results of search strategy with inclusion and exclusions after searches and screening.
methodologic quality. The two reviewers (J.A. and A.K.) independently extracted data by using a standardized table. This was done in duplicate to increase accuracy. Differences in the extracted data were resolved by consensus. Data extracted included primary and secondary outcomes, year of publication, number of procedures included, and duration of follow-up. The primary outcome for this study was the incidence of significant (>50%) restenosis after a normal early DUS. Secondary outcome end point was the number of reinterventions after a normal early DUS. Statistical analysis. Data were extracted from studies that quoted specific figures for analysis only. Papers that showed data in graph form were not included in the analysis to exclude interpretation bias. Reported continuous variables were pooled and reported as means or medians. The inverse of the Freeman-Tukey double arcsine transformation9 was applied to the reported rates. RESULTS Our search strategy identified 485 relevant articles and abstracts. After the abstracts were screened, 25 full-text articles were found to be relevant to our review and therefore underwent assessment for eligibility and quality inspection of methodology. After this, there were seven articles that included original data assessing the primary outcome and therefore were eligible for the review. Eight articles were excluded due to various reasons: no early scan reported (n ¼ 3), assessment of contralateral side only (n ¼ 2), cost analysis study (n ¼ 2), and no original data (n ¼ 1; Fig). The seven studies that were included in this review (Table) included 2317 procedures. The early scan was reported as normal in 96.7% (95% confidence interval [CI], 92.3%-99.4%) of subjects, and 79 early restenoses
were found. Of the 2238 patients with normal early DUS scans, 2.8% (95% CI, 0.7%-6.0%) developed a subsequent restenosis, and 0.4% (95% CI, 0%-0.9%) underwent a reintervention for this. Of the 160 incidences of restenosis during the study period, 79 (49%) of these were detected on the early postoperative DUS. The follow-up period for the included studies ranged from 12 to 47 months. DISCUSSION Carotid patching was adopted in the 1990s by most clinicians as a valid adjunct to decrease the chance of restenosis.5 DUS has become an accurate noninvasive diagnostic tool to estimate the degree of postoperative restenosis and has been shown to be comparable to angiography.16 Surveillance has become routine practice in many centers around the world; however, there is currently no guidance on it. One study reported an annual growth rate of 1% in carotid DUS by a radiology department between 2000 and 2007.17 It is noteworthy that although there is an increase in the use of DUS, its benefit and clinical value are still in question. This review shows that reported early rate of restenosis is low (2.8%) and much lower than previously reported rates of restenosis of up to 22%.18 Interestingly, of those patients who had a normal early DUS scan, only 2.8% (95% CI, 0.7%-6%) developed a significant restenosis and 0.4% (95% CI, 0%-0.9%) underwent a reintervention for their restenosis during the follow-up period. Given that fewer than one in six patients with restenosis underwent reintervention, this would imply that recurrent stenosis is largely of benign origin and does not require surgical management. However, although we presume the incidence of stroke was low, the actual incidence of stroke for the patients with nontreated restenosis was not reported in the papers evaluated.
JOURNAL OF VASCULAR SURGERY Volume -, Number -
Al Shakarchi et al 3
Table. Summary of included studies assessing duplex ultrasound (DUS) surveillance after carotid endarterectomy (CEA)
Type
Retro/ Centers, Pros No.
Selection bias
Procedures, No.
Study
Year
Mattos10
1993 Cohort
Retro Single
None
Mean F/U 42 months
409
Golledge11
1997 Cohort
Pros
Single
None
Median F/U 36 months
305
88.2 (269)
Zbornikova12 1998 Cohort
Retro Single
None
Mean F/U 12 months
66
71.2 (47)
Roth13
1999 Cohort
Retro Multi
Abu Rahma5
2000 Randomized Pros
Only patients Mean F/U 27.4 who had months an intraoperative scan were included None Mean F/U 47 months
Ricco14
2003 Cohort
Retro Single
None
Abu Rahma15 2015 Cohort
Retro Single
None
Single
F/U
Negative early scan, % (No.)
Mean F/U 24.7 months Mean F/U 20.4 months
Pooled rate, % (95% CI)
Significant restenosis rate, Reinterventions % (No.) rate, % (No.)
99 (405) 9.9 (40)
1.7 (7)
0 (0)
0 (0)
2.1 (1)
0 (0)
221
100 (221) 2.7 (6)
0.5 (1)
222
100 (222) 5.9 (13)
605
98.3 (595)
1 (6)
489
98 (479) 3.1 (15)
2317
96.7 2.8 (0.7-6) (92.3 - 99.4)
NS
0.1 (1) 0.4 (2)
DUS protocol DUS <6 weeks, 6 months. and 1 year after CEA, and then yearly thereafter DUS at 1 day, 1 week, 3, 6, 9, and 12 months after CEA, and then yearly thereafter DUS #2 weeks, and at 3, 6 and 12 months after CEA DUS #2 months after CEA and every 6 months thereafter DUS at 1, 6, and 12 months after CEA and every year thereafter DUS at 4 days after CEA and yearly thereafter DUS #24 hours, at 1, 6, and 12 months, and yearly thereafter
0.4 (0-0.9)
CI, Confidence interval; F/U, follow-up; NS, not significant; Pros, prospective; Retro, retrospective.
The lower rate of reintervention compared with significant stenosis would confirm that many clinicians believe recurrent stenosis is of a benign origin and does not require surgical management. Our results would suggest that there is no significant value for repeating routine DUS after CEA for monitoring of the operated-on side in patients with normal findings on the early DUS examination. If significant contralateral disease is detected, patients should be followed up and managed in accordance with national guidelines and previous publications on the topic.19,20 This present review has some limitations. Most studies reported retrospective data, which carry the inherent selection bias. Unfortunately, the currently published randomized controlled trials on carotid disease, such as the North American Symptomatic Carotid Endarterectomy Trial, did not include the data on early carotid DUS and follow-up of patients with a normal early scan.21 There are still many aspects to DUS, such as differences in the diagnostic criteria used at different institutions and interoperator differences, that may result in significant variations in the classification of carotid artery stenosis. However in the absence of randomized controlled trials, the avoidance
of bias requires pooling of data to attempt to assess the results, as was done in this review. CONCLUSIONS This study demonstrates that recurrent carotid artery stenosis after CEA is not as common as previously reported and that a large proportion can be detected by an early DUS. In patients who have had a normal early scan, our review would suggest that there is little clinical value of long-term surveillance using DUS for the operated-on side. AUTHOR CONTRIBUTIONS Conception and design: JA, NI, AT Analysis and interpretation: JA, DL Data collection: JA, AK Writing the article: JA, DL, JN, AK Critical revision of the article: JA, NI, AT Final approval of the article: JA, DL, JN, AK, NI, AT Statistical analysis: JA Obtained funding: Not applicable Overall responsibility: JA
4 Al Shakarchi et al
REFERENCES 1. Cull DL, Cole T, Miller B, Johnson B, Rawlinson D, Walker E, et al. The value of a carotid duplex surveillance program for stroke prevention. Ann Vasc Surg 2011;25:887-94. 2. Naylor AR, John T, Howlett J, Gillespie I, Allan P, Ruckley CV. Surveillance imaging of the operated artery does not alter clinical outcome following carotid endarterectomy. Br J Surg 1996;83:522-6. 3. Jackson MR, D’Addio VJ, Gillespie DL, O’Donnell SD. The fate of residual defects following carotid endarterectomy detected by early postoperative duplex ultrasound. Am J Surg 1996;172:184-7. 4. Sanders EA, Hoeneveld H, Eikelboom BC, Ludwig JW, Vermeulen FE, Ackerstaff RG. Residual lesions and early recurrent stenosis after carotid endarterectomy. A serial follow-up study with duplex scanning and intravenous digital subtraction angiography. J Vasc Surg 1987;5:731-7. 5. AbuRahma AF, Robinson PA, Mullins DA, Holt SM, Herzog TA, Mowery NT. Frequency of postoperative carotid duplex surveillance and type of closure: results from a randomized trial. J Vasc Surg 2000;32:1043-51. 6. Strandness DE Jr. Screening for carotid disease and surveillance for carotid restenosis. Semin Vasc Surg 2001;14:200-5. 7. Ricotta JJ, O’Brien MS, DeWeese JA. Natural history of recurrent and residual stenosis after carotid endarterectomy: implications for postoperative surveillance and surgical management. Surgery 1992;112: 656-61. 8. Moher D, Liberati A, Tetzlaff J, Altman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the prisma statement. PLoS Med 2009;6:e1000097. 9. Miller JJ. The inverse of the Freeman-Tukey double arcsine transformation. Am Stat 1978;32:138. 10. Mattos MA, van Bemmelen PS, Barkmeier LD, Hodgson KJ, Ramsey DE, Sumner DS. Routine surveillance after carotid endarterectomy: does it affect clinical management? J Vasc Surg 1993;17:819-30. 11. Golledge J, Cuming R, Ellis M, Beattie DK, Davies AH, Greenhalgh RM. Clinical follow-up rather than duplex surveillance after carotid endarterectomy. J Vasc Surg 1997;25:55-63.
JOURNAL OF VASCULAR SURGERY --- 2016
12. Zbornikova V, Lassvik C, Alm A. One year of prospective follow-up after carotid thrombendarterectomyea clinical and duplex study. Acta Neurol Scand 1998;98:248-53. 13. Roth SM, Back MR, Bandyk DF, Avino AJ, Riley V, Johnson BL. A rational algorithm for duplex scan surveillance after carotid endarterectomy. J Vasc Surg 1999;30:453-60. 14. Ricco JB, Camiade C, Roumy J, Neau JP. Modalities of surveillance after carotid endarterectomy: impact of surgical technique. Ann Vasc Surg 2003;17:386-92. 15. AbuRahma AF, Srivastava M, AbuRahma Z, Jackson W, Mousa A, Stone PA, et al. The value and economic analysis of routine postoperative carotid duplex ultrasound surveillance after carotid endarterectomy. J Vasc Surg 2015;62:378-83. 16. Bandyk DF, Moldenhauer P, Lipchik E, Schreiber E, Pohl L, Cato R, et al. Accuracy of duplex scanning in the detection of stenosis after carotid endarterectomy. J Vasc Surg 1988;8:696-702. 17. Zafar AM, Tai R, Murphy TP. Growth of carotid artery duplex ultrasound among Medicare beneficiaries (2000-2007). AJR Am J Roentgenol 2012;198:866-8. 18. Zierler RE, Bandyk DF, Thiele BL, Strandness DE Jr. Carotid artery stenosis following endarterectomy. Arch Surg 1982;117:1408-15. 19. Lovelace TD, Moneta GL, Abou-Zamzam AM Jr, Edwards JM, Yeager RA, Landry GJ, et al. Optimizing duplex follow-up in patients with an asymptomatic internal carotid artery stenosis of less than 60%. J Vasc Surg 2001;33:56-61. 20. AbuRahma AF, Cook CC, Metz MJ, Wulu JT Jr, Bartolucci A. Natural history of carotid artery stenosis contralateral to endarterectomy: results from two randomized prospective trials. J Vasc Surg 2003;38:1154-61. 21. Ferguson GG, Eliasziw M, Barr HW, Clagett GP, Barnes RW, Wallace MC, et al. The North American Symptomatic Carotid Endarterectomy Trial: surgical results in 1415 patients. Stroke 1999;30: 1751-8.
Submitted Dec 8, 2015; accepted Jan 31, 2016.
Patients have traditionally been regularly followed up by duplex ultrasound (DUS) imaging after carotid endarterectomy (CEA). The rationale for surveillance is that disease progression on the contralateral side and postintervention restenosis can reliably be detected, providing an opportunity for timely intervention to reduce the risk of stroke in asymptomatic patients. DUS accurately visualizes the carotid bifurcation and allows development of restenosis in the operated-on carotid artery and progression of disease in the contralateral carotid artery to be assessed.1 Nonrandomized studies have reported mixed results regarding the timing and value of postoperative DUS surveillance, but no consensus has been reached.2,3 Significant restenoses is generally thought to occur within the first 3 months after CEA and is the rationale most centers use to perform an early DUS scan.4 Restenosis has been shown to be more common after primary closure, and patch CEA has become the procedure of choice.5 Although there is good evidence that patch CEA reduces the rate of restenosis compared with primary closure, the clinical relevance of radiologically defined restenosis after patch CEA is not clear. Indeed, some authors believe that such stenoses have a low probability of future From the Department of Renal Surgerya and Department of Vascular Surgery,b University Hospital Birmingham. Author conflict of interest: none. Correspondence: Julien Al Shakarchi, MBChB, Department of Renal and Vascular Surgery, University Hospital Birmingham, Birmingham, B15 2TH, UK (e-mail: [email protected]). The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a conflict of interest. 0741-5214 Copyright Ó 2016 by the Society for Vascular Surgery. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jvs.2016.01.054
neurologic events and that intervention is not warranted for such patients.6,7 Therefore, in view of this and advancements in medical management, one should question the value of performing routine carotid DUS scanning after surgery. The purpose of this study was to assess and systematically review the evidence basis for long-term surveillance after CEA and an early DUS with a normal result. Early DUS was defined as #3 months after surgery. METHODS Search methodology for identification of relevant studies. Searches of PubMed Central, MEDLINE, and the Cochrane Library were performed using combinations of the search terms carotid endarterectomy or carotid surgery with ultrasound, ultrasonography, duplex or Doppler, and timing or follow-up or surveillance or postoperative, to identify articles published between January 1, 1990, and October 31, 2015, in the English language. This date limit was set because patch CEA became a more routine and common procedure in the 1990s. The references cited in selected articles were reviewed for any further relevant available studies. Articles that assessed other imaging techniques were excluded. We included published randomized trials and observational studies. We excluded abstracts, case reports, review articles, editorials without original data, and non-English publications. Gray literature was not searched or included. The systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.8 Therefore, all included studies were assessed for inclusion on the basis of their topic, type of study, method, number of patients included, and availability of their original results. Primary and secondary outcomes. All studies that met the above set criteria were reviewed and assessed for 1
JOURNAL OF VASCULAR SURGERY --- 2016
2 Al Shakarchi et al
Fig. Flow chart shows results of search strategy with inclusion and exclusions after searches and screening.
methodologic quality. The two reviewers (J.A. and A.K.) independently extracted data by using a standardized table. This was done in duplicate to increase accuracy. Differences in the extracted data were resolved by consensus. Data extracted included primary and secondary outcomes, year of publication, number of procedures included, and duration of follow-up. The primary outcome for this study was the incidence of significant (>50%) restenosis after a normal early DUS. Secondary outcome end point was the number of reinterventions after a normal early DUS. Statistical analysis. Data were extracted from studies that quoted specific figures for analysis only. Papers that showed data in graph form were not included in the analysis to exclude interpretation bias. Reported continuous variables were pooled and reported as means or medians. The inverse of the Freeman-Tukey double arcsine transformation9 was applied to the reported rates. RESULTS Our search strategy identified 485 relevant articles and abstracts. After the abstracts were screened, 25 full-text articles were found to be relevant to our review and therefore underwent assessment for eligibility and quality inspection of methodology. After this, there were seven articles that included original data assessing the primary outcome and therefore were eligible for the review. Eight articles were excluded due to various reasons: no early scan reported (n ¼ 3), assessment of contralateral side only (n ¼ 2), cost analysis study (n ¼ 2), and no original data (n ¼ 1; Fig). The seven studies that were included in this review (Table) included 2317 procedures. The early scan was reported as normal in 96.7% (95% confidence interval [CI], 92.3%-99.4%) of subjects, and 79 early restenoses
were found. Of the 2238 patients with normal early DUS scans, 2.8% (95% CI, 0.7%-6.0%) developed a subsequent restenosis, and 0.4% (95% CI, 0%-0.9%) underwent a reintervention for this. Of the 160 incidences of restenosis during the study period, 79 (49%) of these were detected on the early postoperative DUS. The follow-up period for the included studies ranged from 12 to 47 months. DISCUSSION Carotid patching was adopted in the 1990s by most clinicians as a valid adjunct to decrease the chance of restenosis.5 DUS has become an accurate noninvasive diagnostic tool to estimate the degree of postoperative restenosis and has been shown to be comparable to angiography.16 Surveillance has become routine practice in many centers around the world; however, there is currently no guidance on it. One study reported an annual growth rate of 1% in carotid DUS by a radiology department between 2000 and 2007.17 It is noteworthy that although there is an increase in the use of DUS, its benefit and clinical value are still in question. This review shows that reported early rate of restenosis is low (2.8%) and much lower than previously reported rates of restenosis of up to 22%.18 Interestingly, of those patients who had a normal early DUS scan, only 2.8% (95% CI, 0.7%-6%) developed a significant restenosis and 0.4% (95% CI, 0%-0.9%) underwent a reintervention for their restenosis during the follow-up period. Given that fewer than one in six patients with restenosis underwent reintervention, this would imply that recurrent stenosis is largely of benign origin and does not require surgical management. However, although we presume the incidence of stroke was low, the actual incidence of stroke for the patients with nontreated restenosis was not reported in the papers evaluated.
JOURNAL OF VASCULAR SURGERY Volume -, Number -
Al Shakarchi et al 3
Table. Summary of included studies assessing duplex ultrasound (DUS) surveillance after carotid endarterectomy (CEA)
Type
Retro/ Centers, Pros No.
Selection bias
Procedures, No.
Study
Year
Mattos10
1993 Cohort
Retro Single
None
Mean F/U 42 months
409
Golledge11
1997 Cohort
Pros
Single
None
Median F/U 36 months
305
88.2 (269)
Zbornikova12 1998 Cohort
Retro Single
None
Mean F/U 12 months
66
71.2 (47)
Roth13
1999 Cohort
Retro Multi
Abu Rahma5
2000 Randomized Pros
Only patients Mean F/U 27.4 who had months an intraoperative scan were included None Mean F/U 47 months
Ricco14
2003 Cohort
Retro Single
None
Abu Rahma15 2015 Cohort
Retro Single
None
Single
F/U
Negative early scan, % (No.)
Mean F/U 24.7 months Mean F/U 20.4 months
Pooled rate, % (95% CI)
Significant restenosis rate, Reinterventions % (No.) rate, % (No.)
99 (405) 9.9 (40)
1.7 (7)
0 (0)
0 (0)
2.1 (1)
0 (0)
221
100 (221) 2.7 (6)
0.5 (1)
222
100 (222) 5.9 (13)
605
98.3 (595)
1 (6)
489
98 (479) 3.1 (15)
2317
96.7 2.8 (0.7-6) (92.3 - 99.4)
NS
0.1 (1) 0.4 (2)
DUS protocol DUS <6 weeks, 6 months. and 1 year after CEA, and then yearly thereafter DUS at 1 day, 1 week, 3, 6, 9, and 12 months after CEA, and then yearly thereafter DUS #2 weeks, and at 3, 6 and 12 months after CEA DUS #2 months after CEA and every 6 months thereafter DUS at 1, 6, and 12 months after CEA and every year thereafter DUS at 4 days after CEA and yearly thereafter DUS #24 hours, at 1, 6, and 12 months, and yearly thereafter
0.4 (0-0.9)
CI, Confidence interval; F/U, follow-up; NS, not significant; Pros, prospective; Retro, retrospective.
The lower rate of reintervention compared with significant stenosis would confirm that many clinicians believe recurrent stenosis is of a benign origin and does not require surgical management. Our results would suggest that there is no significant value for repeating routine DUS after CEA for monitoring of the operated-on side in patients with normal findings on the early DUS examination. If significant contralateral disease is detected, patients should be followed up and managed in accordance with national guidelines and previous publications on the topic.19,20 This present review has some limitations. Most studies reported retrospective data, which carry the inherent selection bias. Unfortunately, the currently published randomized controlled trials on carotid disease, such as the North American Symptomatic Carotid Endarterectomy Trial, did not include the data on early carotid DUS and follow-up of patients with a normal early scan.21 There are still many aspects to DUS, such as differences in the diagnostic criteria used at different institutions and interoperator differences, that may result in significant variations in the classification of carotid artery stenosis. However in the absence of randomized controlled trials, the avoidance
of bias requires pooling of data to attempt to assess the results, as was done in this review. CONCLUSIONS This study demonstrates that recurrent carotid artery stenosis after CEA is not as common as previously reported and that a large proportion can be detected by an early DUS. In patients who have had a normal early scan, our review would suggest that there is little clinical value of long-term surveillance using DUS for the operated-on side. AUTHOR CONTRIBUTIONS Conception and design: JA, NI, AT Analysis and interpretation: JA, DL Data collection: JA, AK Writing the article: JA, DL, JN, AK Critical revision of the article: JA, NI, AT Final approval of the article: JA, DL, JN, AK, NI, AT Statistical analysis: JA Obtained funding: Not applicable Overall responsibility: JA
4 Al Shakarchi et al
REFERENCES 1. Cull DL, Cole T, Miller B, Johnson B, Rawlinson D, Walker E, et al. The value of a carotid duplex surveillance program for stroke prevention. Ann Vasc Surg 2011;25:887-94. 2. Naylor AR, John T, Howlett J, Gillespie I, Allan P, Ruckley CV. Surveillance imaging of the operated artery does not alter clinical outcome following carotid endarterectomy. Br J Surg 1996;83:522-6. 3. Jackson MR, D’Addio VJ, Gillespie DL, O’Donnell SD. The fate of residual defects following carotid endarterectomy detected by early postoperative duplex ultrasound. Am J Surg 1996;172:184-7. 4. Sanders EA, Hoeneveld H, Eikelboom BC, Ludwig JW, Vermeulen FE, Ackerstaff RG. Residual lesions and early recurrent stenosis after carotid endarterectomy. A serial follow-up study with duplex scanning and intravenous digital subtraction angiography. J Vasc Surg 1987;5:731-7. 5. AbuRahma AF, Robinson PA, Mullins DA, Holt SM, Herzog TA, Mowery NT. Frequency of postoperative carotid duplex surveillance and type of closure: results from a randomized trial. J Vasc Surg 2000;32:1043-51. 6. Strandness DE Jr. Screening for carotid disease and surveillance for carotid restenosis. Semin Vasc Surg 2001;14:200-5. 7. Ricotta JJ, O’Brien MS, DeWeese JA. Natural history of recurrent and residual stenosis after carotid endarterectomy: implications for postoperative surveillance and surgical management. Surgery 1992;112: 656-61. 8. Moher D, Liberati A, Tetzlaff J, Altman DG; The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the prisma statement. PLoS Med 2009;6:e1000097. 9. Miller JJ. The inverse of the Freeman-Tukey double arcsine transformation. Am Stat 1978;32:138. 10. Mattos MA, van Bemmelen PS, Barkmeier LD, Hodgson KJ, Ramsey DE, Sumner DS. Routine surveillance after carotid endarterectomy: does it affect clinical management? J Vasc Surg 1993;17:819-30. 11. Golledge J, Cuming R, Ellis M, Beattie DK, Davies AH, Greenhalgh RM. Clinical follow-up rather than duplex surveillance after carotid endarterectomy. J Vasc Surg 1997;25:55-63.
JOURNAL OF VASCULAR SURGERY --- 2016
12. Zbornikova V, Lassvik C, Alm A. One year of prospective follow-up after carotid thrombendarterectomyea clinical and duplex study. Acta Neurol Scand 1998;98:248-53. 13. Roth SM, Back MR, Bandyk DF, Avino AJ, Riley V, Johnson BL. A rational algorithm for duplex scan surveillance after carotid endarterectomy. J Vasc Surg 1999;30:453-60. 14. Ricco JB, Camiade C, Roumy J, Neau JP. Modalities of surveillance after carotid endarterectomy: impact of surgical technique. Ann Vasc Surg 2003;17:386-92. 15. AbuRahma AF, Srivastava M, AbuRahma Z, Jackson W, Mousa A, Stone PA, et al. The value and economic analysis of routine postoperative carotid duplex ultrasound surveillance after carotid endarterectomy. J Vasc Surg 2015;62:378-83. 16. Bandyk DF, Moldenhauer P, Lipchik E, Schreiber E, Pohl L, Cato R, et al. Accuracy of duplex scanning in the detection of stenosis after carotid endarterectomy. J Vasc Surg 1988;8:696-702. 17. Zafar AM, Tai R, Murphy TP. Growth of carotid artery duplex ultrasound among Medicare beneficiaries (2000-2007). AJR Am J Roentgenol 2012;198:866-8. 18. Zierler RE, Bandyk DF, Thiele BL, Strandness DE Jr. Carotid artery stenosis following endarterectomy. Arch Surg 1982;117:1408-15. 19. Lovelace TD, Moneta GL, Abou-Zamzam AM Jr, Edwards JM, Yeager RA, Landry GJ, et al. Optimizing duplex follow-up in patients with an asymptomatic internal carotid artery stenosis of less than 60%. J Vasc Surg 2001;33:56-61. 20. AbuRahma AF, Cook CC, Metz MJ, Wulu JT Jr, Bartolucci A. Natural history of carotid artery stenosis contralateral to endarterectomy: results from two randomized prospective trials. J Vasc Surg 2003;38:1154-61. 21. Ferguson GG, Eliasziw M, Barr HW, Clagett GP, Barnes RW, Wallace MC, et al. The North American Symptomatic Carotid Endarterectomy Trial: surgical results in 1415 patients. Stroke 1999;30: 1751-8.
Submitted Dec 8, 2015; accepted Jan 31, 2016.