Carotid Endarterectomy Outcomes in the Elderly: A Canadian Institutional Experience.

BACKGROUND: Carotid endarterectomy (CEA) is a well-established surgical intervention for stroke prevention in patients with carotid stenosis of all ages. However, the decision to proceed to operate in the elderly involves a more complicated risk-benefit assessment due in part to increased comorbidities and reduced life expectancy. Some studies suggest that CEA is more risky in the elderly with worse outcomes, whereas others have found no difference. Our objective was to evaluate and compare outcomes of CEA between elderly and younger patients at our institution. METHODS: All hospital charts were reviewed for consecutive patients undergoing CEA from the Jewish General Hospital and the Royal Victoria Hospital from October 2009 to December 2015. Primary outcomes were ipsilateral stroke, death, and restenosis at 30 days and 1 year. Secondary outcomes were cranial nerve injury, myocardial infarction (MI), hematoma, wound infection, cerebral hyperperfusion, and transient ischemic attacks within 30 days. Primary and secondary outcomes were compared between patients aged ≥80 years and <80 years. RESULTS: A total of 361 patients were included in this study with a mean age of 70.2 ± 9.5 years (n = 247 [68.4%] male and n = 272 [75.8%] symptomatic). Elderly patients were more often symptomatic (93.8% vs. 71.6%, P < 0.0001) and had an increased length of stay (2.8 ± 5.3 vs. 1.6 ± 1.8, P = 0.001). There was no statistically significant difference in primary outcomes between patients aged <80 years and ≥80 years, including 30-day stroke (1.7% vs. 0%), death (no deaths in either group), restenosis (8.8% vs. 12.3%), 1-year stroke (1.7% vs. 0%), death (0.7% vs. 0%), or restenosis (14.9% vs. 13.8%). However, elderly patients had significantly increased MI risk postoperatively (4.6% vs. 0.7%, P = 0.01). Other complications, including cranial nerve injury (3.7% in <80 years vs. 4.6% in the elderly group), were similar between the groups. CONCLUSIONS: We found that CEA in the elderly does not have an increased risk of stroke or death up to one year postoperatively. However, the postoperative length of stay is increased and complicated by significantly more MIs, which should weigh into the decision of whether to perform CEA on an elderly patient.

Plaque echodensity and textural features are associated with histologic carotid plaque instability.

BACKGROUND: Carotid plaque echodensity and texture features predict cerebrovascular symptomatology. Our purpose was to determine the association of echodensity and textural features obtained from a digital image analysis (DIA) program with histologic features of plaque instability as well as to identify the specific morphologic characteristics of unstable plaques. METHODS: Patients scheduled to undergo carotid endarterectomy were recruited and underwent carotid ultrasound imaging. DIA was performed to extract echodensity and textural features using Plaque Texture Analysis software (LifeQ Medical Ltd, Nicosia, Cyprus). Carotid plaque surgical specimens were obtained and analyzed histologically. Principal component analysis (PCA) was performed to reduce imaging variables. Logistic regression models were used to determine if PCA variables and individual imaging variables predicted histologic features of plaque instability. RESULTS: Image analysis data from 160 patients were analyzed. Individual imaging features of plaque echolucency and homogeneity were associated with a more unstable plaque phenotype on histology. These results were independent of age, sex, and degree of carotid stenosis. PCA reduced 39 individual imaging variables to five PCA variables. PCA1 and PCA2 were significantly associated with overall plaque instability on histology (both P = .02), whereas PCA3 did not achieve statistical significance (P = .07). CONCLUSIONS: DIA features of carotid plaques are associated with histologic plaque instability as assessed by multiple histologic features. Importantly, unstable plaques on histology appear more echolucent and homogeneous on ultrasound imaging. These results are independent of stenosis, suggesting that image analysis may have a role in refining the selection of patients who undergo carotid endarterectomy.

Patency of the contralateral internal iliac artery in aortouni-iliac endografting.

OBJECTIVE: This study determined the outcome of the contralateral internal iliac artery (IIA) in patients undergoing aortouni-iliac (AUI) endovascular abdominal aortic aneurysm repair (EVAR) with a femorofemoral bypass. METHODS: This retrospective study evaluated 131 consecutive patients undergoing AUI EVAR with femorofemoral bypass at the McGill University Health Center from October 2001 to November 2010. One hundred patients with preoperatively patent contralateral IIA met inclusion criteria for the study. Preoperative demographics and preoperative and postoperative contrast-enhanced computed tomography (CT) scans with multiplanar reconstruction were reviewed for all patients. The last available postoperative CT imaging for all patients was identified and evaluated for contralateral IIA patency. Patency in preoperative and postoperative CT scans was defined as contrast enhancement of the IIA in continuity with the external iliac artery and absence of >50% stenosis at the origin of the IIA. Clinical outcome focused on postoperative pelvic ischemia and reported symptoms of buttock claudication. RESULTS: Mean age at the time of operation was 77.6 ± 6.7 years, and 78% were male. Mean clinical follow-up was 29.2 months after surgery, and mean follow-up of imaging with intravenous contrast was 30.6 months. The last imaging follow-up showed 67 patients (67%) had a patent contralateral IIA and that the IIAs in 33 patients (33%) were occluded (25 [76%]) or stenotic (8 [24%]). Of the patients with IIA occlusion, 80% (20 of 25) were occluded on the first postoperative imaging (median, 8.5 days). Buttock claudication was reported in 18% (6 of 33 patients) with an occluded IIA compared with only 3% (2 of 67 patients) of patients with a patent contralateral IIA on final imaging follow-up (18% vs 3%; P = .014). There were no observed cases of buttock necrosis, spinal ischemia, or colonic ischemia. CONCLUSIONS: Our findings suggest that AUI EVAR with femorofemoral bypass is associated with a significant incidence of contralateral IIA malperfusion on postoperative CT imaging. Occlusion appears to occur early in the postoperative period in most patients, and patient-reported buttock claudication is observed significantly more frequently in patients with an occluded IIA compared with those with a patent IIA. More serious pelvic ischemic complications were not seen in this series. Further study is required to determine whether modification of the procedure can prevent contralateral IIA occlusion and the development of buttock claudication.

Predictive value of negative initial postoperative imaging after endovascular aortic aneurysm repair.

OBJECTIVE: The risk of endoleak and reintervention after endovascular abdominal aortic aneurysm repair necessitates lifelong surveillance, which has associated costs, radiation exposure, and risk of nephrotoxicity. The best imaging method and timing of surveillance remain controversial. We sought to determine if a negative result of first postoperative imaging by computed tomography (CT) scan was predictive of decreased need for reintervention. We hypothesized that initial negative postoperative imaging could identify a low-risk cohort of patients who could be observed less frequently. METHODS: Retrospective review of prospectively collected institutional outcomes data (2004-2009) included stratification according to postoperative imaging results. Baseline characteristics and aneurysm morphology were compared between the two groups. Cox regression analysis was used to identify risk factors predictive for endoleak-related reintervention. Kaplan-Meier survival curves were used to plot freedom from all-cause reintervention and endoleak-related reintervention for the two groups. RESULTS: A total of 134 patients were included in the analysis. A total of 107 patients (80%) had negative initial postoperative imaging, whereas 27 patients (20%) had evidence of an endoleak. There were no significant differences between the two groups in terms of comorbidities or anticoagulation status. Kaplan-Meier survival curves showed that there was a significant difference between those patients who had a negative initial CT scan and those who had a positive scan for endoleak in terms of both overall reintervention rates and leak-related reintervention rates. Endoleak on the first postoperative CT scan was associated with a hazard ratio of 6.37 (confidence interval, 2.02-20.10; P = .002) for leak-related reintervention and a hazard ratio of 6.01 (confidence interval, 2.24-16.17; P < .001) for all-cause reintervention. CONCLUSIONS: Patients with negative initial postoperative imaging were significantly less likely to require repeated interventions. These data suggest that these patients are candidates for less rigorous screening protocols.

Early results from a Canadian multicenter prospective registry of the Endurant stent graft for endovascular treatment of abdominal aortic aneurysms.

PURPOSE: To report the early results of a multicenter registry of endovascular aneurysm repair (EVAR) using the Endurant stent-graft. METHODS: Patients having elective treatment of infrarenal abdominal aortic aneurysm (AAA) with the Endurant stent-graft at 3 Canadian centers were enrolled in a prospective registry between September 2008 and January 2010. In the 16-month period, 111 patients (90 men; mean age 75 years, range 53-93) were registered. Thirty-seven (33.3%) patients had challenging anatomy: short proximal aortic necks (n=17), large diameter (>28 mm) aortic necks (n=4), angulated (>60°) necks (n=3), and small (<15 mm) external iliac arteries (n=21). Outcomes evaluated included survival, endoleak, aneurysm expansion >5 mm, secondary intervention, stent-graft migration, and graft thrombosis. RESULTS: The overall technical success rate was 100%. Nineteen (17.1%) patients experienced perioperative complications. After a mean follow-up of 6 months (range 0.1-16), mortality in the series was 4.5%: 1 perioperative death (multisystem organ failure) and 4 (3.6%) late deaths (3 cardiac, 1 cancer). Clinical and imaging follow-up past the perioperative period were available in 107 (96.4%) and 99 (89.2%) patients, respectively. Among the latter, 9 (9.1%) had a type II endoleak on the first scan; 4 resolved spontaneously. Three (3.0%) patients developed graft limb thrombosis in follow-up; one required an intervention. There was no graft migration, aneurysm expansion, secondary intervention for endoleak, aneurysm rupture, or conversion. CONCLUSION: Early results from this prospective multicenter registry indicate that the Endurant stent-graft is a safe option for elective EVAR in selected AAA patients. Longer follow-up is required to determine the durability of these outcomes.

Carotid artery angioplasty and stenting: introduction of a new technique into an established vascular surgery center.

BACKGROUND: The aim of this study was to review our initial experience with the introduction of carotid artery angioplasty and stenting as a treatment for carotid stenosis in high-risk patients and compare clinical outcomes to carotid endarterectomy patients treated over the same time period at our center. METHODS: A total of 265 carotid revascularization procedures (45 carotid artery angioplasty and stenting and 220 carotid endarterectomy) were performed over 3 years period. In the carotid artery angioplasty and stenting group, 93% were at high risk according to the current reporting standards. Death, neurological events, and restenosis rates were compared at 30 days and at most recent follow-up. RESULTS: Mean follow-up for all patients was 18 months (range 0-48 months). Carotid artery angioplasty and stenting group had higher cardiac risk than carotid endarterectomy group (13% vs 2%, P < .05). High-risk carotid lesions were present in 67% of carotid artery angioplasty and stenting patients. There was a tendency toward higher restenosis rate in carotid artery angioplasty and stenting than in carotid endarterectomy patients (35% vs 15%, P = .06). Combined stroke and death was higher in the carotid stenting group (4% and 9%) compared to the carotid endarterectomy group (0.5% and 0.5%) at 30 days and at late follow-up, respectively (P = .04 and .00). CONCLUSION: Restenosis and stroke were observed more frequently in our initial experience in patients undergoing carotid artery angioplasty and stenting compared with carotid endarterectomy patients during the same time period. These differences disappeared in high-risk patients. Further studies, to evaluate the effect of the learning curve on early results as well as follow-up for intermediate and long-term durability of carotid artery angioplasty and stenting in high-risk patients, are required.

Arterial trauma during central venous catheter insertion: Case series, review and proposed algorithm.

BACKGROUND: Percutaneous catheterization is a frequently-used technique to gain access to the central venous circulation. Inadvertent arterial puncture is often without consequence, but can lead to devastating complications if it goes unrecognized and a large-bore dilator or catheter is inserted. The present study reviews our experience with these complications and the literature to determine the safest way to manage catheter-related cervicothoracic arterial injury (CRCAI). METHODS: We retrospectively identified all cases of iatrogenic carotid or subclavian injury following central venous catheterization at three large institutions in Montreal. We reviewed the French and English literature published from 1980 to 2006, in PubMed, and selected studies with the following criteria: arterial misplacement of a large-caliber cannula (>/=7F), adult patients (>18 years old), description of the method for managing arterial trauma, reference population (denominator) to estimate the success rate of the therapeutic option chosen. A consensus panel of vascular surgeons, anesthetists and intensivists reviewed this information and proposed a treatment algorithm. RESULTS: Thirteen patients were treated for CRCAI in participating institutions. Five of them underwent immediate catheter removal and compression, and all had severe complications resulting in major stroke and death in one patient, with the other four undergoing further intervention for a false aneurysm or massive bleeding. The remaining eight patients were treated by immediate open repair (six) or through an endovascular approach (two) for subclavian artery trauma without complications. Five articles met all our inclusion criteria, for a total of 30 patients with iatrogenic arterial cannulation: 17 were treated by immediate catheter removal and direct external pressure; eight (47%) had major complications requiring further interventions; and two died. The remaining 13 patients submitted to immediate surgical exploration, catheter removal and artery repair under direct vision, without any complications (47% vs 0%, P = .004). CONCLUSION: During central venous placement, prevention of arterial puncture and cannulation is essential to minimize serious sequelae. If arterial trauma with a large-caliber catheter occurs, prompt surgical or endovascular treatment seems to be the safest approach. The pull/pressure technique is associated with a significant risk of hematoma, airway obstruction, stroke, and false aneurysm. Endovascular treatment appears to be safe for the management of arterial injuries that are difficult to expose surgically, such as those below or behind the clavicle. After arterial repair, prompt neurological evaluation should be performed, even if it requires postponing elective intervention. Imaging is suggested to exclude arterial complications, especially if arterial trauma site was not examined and repaired.

Specific shortcomings of endograft design.

Further to the rapid enlargement of an aneurysm to 5.6 cm in diameter after 3 years of surveillance, a 79-year-old patient was fitted with a Vanguard modular stent graft and monitored on a regular basis for 6 years. Two years later, the aneurysmal sac ruptured. The patient died 1 month after an open surgery. The device was devoid of any encapsulation and the ipsilateral limb was detached from the body. The Nitinol skeleton was mostly maintained, however, some polypropylene sutures were broken. The resulting motion of the sharp-angled Nitinol wires caused abrasion and resulted in a few localized holes that were sufficient to permit blood to percolate through the textile wall. Some polyester yarns in the warp direction were ruptured. The Nitinol wire used in this device was shown to be corrosion resistant but the selection of the polypropylene suture was inappropriate. Because this technology is maturing rapidly, these weaknesses can be avoided in the future generations of endovascular devices. It is recommended that these Nitinol wires be sutured to the fabric and that polyester yarns stronger than 68 decitex in tubes 8 mm in diameter are selected.

Blunt thoracic aortic injury: a single institution comparison of open and endovascular management.

OBJECTIVE: To review the treatment of blunt thoracic aortic injuries (BAI) at a single institution over the past 12 years and compare pre-, peri-, and postoperative variables and outcomes of both open (OR) and thoracic endovascular (TEVAR) repair of these injuries. METHODS: All cases of confirmed BAI from 1994 to present were included in this retrospective review. Data collected included demographic data, injury severity score, Glasgow coma score, arrival hemodynamic variables, and associated injuries. Operative data included: type of procedure (OR or TEVAR), duration of procedure, need for and amount of blood transfused, use of anticoagulation, type of anesthesia, and service performing the procedure. Outcomes evaluated were: death, paraplegia, length of stay, days ventilated, and procedure related complications. Specific to EVAR; access, stent graft type and number, presence of endoleak and long-term clinical and radiologic follow-up were evaluated. RESULTS: Thirty cases of blunt thoracic aortic injury were identified. Two patients received no treatment and died, 28 patients were treated (OR 16, TEVAR 12) and included for comparison. There were no significant differences between groups with respect to preoperative variables with the exception of significantly more associated intra-abdominal injuries in the TEVAR group (P = .03). Five patients in the OR group (31.2%) died in the perioperative period. There were no deaths in the TEVAR group (P =.05). One OR patient (6.25%) suffered postoperative paraplegia. No paraplegia occurred in the TEVAR group. Intraoperative variables were similar between groups with the exception of mean units of blood transfused (OR 8.5 units, vs TEVAR 0.2 units, P = .002). Ten patients in the OR group either died or had a procedure related complication compared with none in the TEVAR group (P = .001). There was no difference in length of stay or length of mechanical ventilation between the groups. There were no procedure or device related complications in the TEVAR group during follow-up (mean 15.3 months, range 1 to 53.5 months). CONCLUSIONS: Endovascular repair of BAI results in significantly less combined mortality and morbidity when compared to OR. Significantly less blood is needed intraoperatively in the TEVAR group. No complications from stent graft insertion have been observed during follow-up. Endovascular repair is replacing open repair as the treatment of choice for BAI at our institution.

Interobserver variability of carotid Doppler peak velocity measurements among technologists in an ICAVL-accredited vascular laboratory.

OBJECTIVE: This study was designed to investigate interobserver variability in the measurement of internal carotid artery (ICA) peak systolic velocity (PSV). We hypothesize that the reproducibility of repeated duplex scanning parameters, in the hands of very experienced vascular technologists in a laboratory accredited by the Intersocietal Commission for Accreditation of Vascular Laboratories, would be excellent. METHODS: Thirty-one patients underwent carotid duplex scanning by three vascular technologists using the same duplex scanning system. They examined patients with the laboratory's standard protocol. Statistical analysis of the sources of variation was carried out with two-way analysis of variance. The Altman-Bland method was used to detect bias and evaluate the interval of agreement between technologists for the ICA PSV on a continuous scale. The kappa statistic enabled measurement of agreement for ICA PSV on a categorical scale of stenosis (<50%, 50%-70%, >70%). RESULTS: Patient variability was responsible for 97.2% of the total variance, with only 0.58% (P<.005) attributed to the technologists. The level of agreement on a continuous scale between the measurements of ICA PSV by our technologists is wide. For individual patients it ranged from -25% to 43% between technologists A and B, -27% to 43% between technologists A and C, and -27% to 31% between technologists B and C. When we compared the three technologists, no systematic overestimation or underestimation of the ICA PSV was found (ie, no fixed bias). The level of agreement between the technologists did not depend on the value of the PSV (ie, no proportional bias). However, analysis of ICA PSV agreement on a categorical scale revealed almost perfect agreement (kappa>0.8). CONCLUSION: From measurements of PSV, the severity of carotid stenosis can be reproducibly categorized into ranges (<50%, 50%-70%, >70). However, the unacceptably wide interobserver variation of ICA PSV on a continuous scale makes the interchangeability of our technologists' measurements problematic for clinical use, as in determination of progression of severity of stenosis. When an ICA PSV measurement is in the vicinity of a cutoff value, the diagnostic accuracy may be improved with the use of additional diagnostic testing.