Joel Gagnon

Ankle–Brachial Index for Assessment of Peripheral Arterial Disease

Although other methods exist to assess the peripheral vasculature, measurement of the ankle–brachial index remains a simple, reliable method for diagnosing peripheral arterial disease. This video presents the indications for use of the ankle–brachial index and demonstrates how it is measured.

Diagnosis and management of iliofemoral deep vein thrombosis: clinical practice guideline

Venous thromboembolism, presenting as deep vein thrombosis (DVT) or pulmonary embolism, affects over 35 000 Canadians each year.[1][1] It is associated with substantial morbidity, mortality and burden on the Canadian health care system, with one-month mortality rates estimated at 6% for DVT and 12%

A Practical Guide to Magnetic Resonance Vascular Imaging: Techniques and Applications

Magnetic resonance angiography is a technique used to image both central and peripheral arteries using contrast and noncontrast techniques. These techniques are similar in that a bright signal, which appears white within blood vessels, is generated and the background tissues, veins, and stationary tissues are dark. This allows for assessment of anatomy and vascular disease. Extracellular gadolinium-based contrast agents allow for excellent visualization of both central and peripheral arteries. Acquiring images during first pass is required for high-contrast images within arteries, thereby limiting contamination with contrast enhancement of veins and soft tissue. Contrast-enhanced techniques using time-resolved angiography and blood pool contrast agents minimize this temporal limitation. Noncontrast techniques eliminate the uncommon but potentially fatal complications associated with gadolinium contrast agents, such as nephrogenic systemic fibrosis. These techniques including phase contrast and time-of-flight sequences have inferior contrast resolution compared with contrast-enhanced techniques and are susceptible to artifacts, which can limit interpretation. The advantage, however, is the ability to assess vascular disease in patients with severe renal failure without the added risks of gadolinium contrast media. The aim of this review is to outline the different techniques available for imaging both the arterial and venous systems, their advantages and disadvantages, and the indications in vascular disease.

Combined CT, Fluoroscopic and IVUS Guidance for Percutaneous Treatment of a Postsurgical Pseudoaneurysm Following Repair of Ascending Thoracic Aortic Aneurysm

Thoracic aortic pseudoaneurysms are a recognized complication following aortic arch replacement. The established first line treatment is surgical repair; however, this may not be feasible in all patients. Percutaneous treatment of ascending thoracic pseudoaneurysms has been described as an alternative for nonsurgical candidates. Utilization of multimodality imaging can prove invaluable in minimizing the risk of potentially fatal intra-procedural complications. We present a case of successful embolization using computer tomography-guided direct percutaneous puncture of the pseudoaneurysm, with concomitant endovascular treatment under fluoroscopic and intravascular ultrasound guidance in a patient with challenging vascular anatomy.

Using a Chimney to Make a Sandwich: Salvage of a Multibranched Thoracoabdominal Aortic Endograft with a Type IIIb Endoleak

BACKGROUND The advent of branched and fenestrated aortic endografts has facilitated the treatment of increasingly complex aortic pathology. The management of complications and endoleaks involving the branches and fenestrations of these grafts represents an increasingly significant clinical and technical challenge. METHODS A 79-year-old woman developed a rare type IIIb endoleak from a tear in the graft fabric immediately posterior to the celiac axis branch 3 years after the placement of an off-the-shelf branched endograft for a type II thoracoabdominal aortic aneurysm. The patient presented urgently with abdominal pain and a maximal aneurysm diameter of 15.3 cm. RESULTS The operative plan was to create a chimney graft completely within the original branched endograft to cover the defect and maintain celiac branch flow. The celiac trunk was accessed from a left axillary approach and access for the main endograft body was achieved via the left femoral artery. Two balloon-expandable covered stents were deployed from the celiac branch extending into the main endograft as a chimney and molded to 2 aortic extension cuffs to cover the fabric defect. The resultant configuration was a modified-sandwich graft within the original stent graft and resulted in successful exclusion of the endoleak. Postoperative imaging at 1, 6, and 12 months has demonstrated continued patency of the celiac trunk, no further endoleak, and a 16-mm reduction in aneurysm size. CONCLUSIONS The chimney technique was successfully applied as an endovascular option to salvage a multibranched endograft with a significant and anatomically unfavorable defect. Careful follow-up and additional clinical study are required to clarify the role of off-the-shelf solutions in complex endoleak management.

Use of short-radius centrifugation to augment ankle-brachial indices.

Background Peripheral arterial disease is mainly caused by atherosclerosis and is characterized by decreased circulation, lower blood pressure, and insufficient tissue perfusion in the lower extremities. The hemodynamics of standing and altered gravity environments have been well studied relative to arm blood pressures but are less well understood for ankle pressures. Methods Because regional blood pressure depends, in part, on the gravitational pressure gradient, we hypothesized that artificial gravity exposure on a short-arm centrifuge with the center of rotation above the head would increase blood pressure in the lower extremities. Cardiovascular parameters for 12 healthy subjects were measured during exposure to supine short-arm centrifugation at 20, 25, and 30 revolutions per minute (rpm), corresponding to centripetal accelerations of 0.94, 1.47, and 2.11 Gz at the foot level, respectively. Results Systolic ankle blood pressure significantly increased at all levels of centrifugation. Ankle-brachial indices (the ratio of systolic ankle to arm blood pressures) increased significantly from 1.17 ± 0.03 to 1.58 ± 0.03 at 0.94 Gz (P < 0.005), 1.74 ± 0.02 at 1.47 Gz (P < 0.005), and 1.89 ± 0.06 at 2.11 Gz (P < 0.005). Systolic arm blood pressure significantly increased at 2.11 Gz, but heart rate did not change significantly. All parameters returned to normal after cessation of centrifugation. Conclusions We demonstrated that short-radius centrifugation leads to an increase in ankle-brachial indices. This could have potential implications for the treatment of peripheral arterial disease.

Comparison of cyanoacrylate embolization and radiofrequency ablation for the treatment of varicose veins

Objective To review clinical outcomes of varicose vein patients treated with cyanoacrylate embolization and radiofrequency ablation at our institution. Methods A retrospective review of patients who underwent cyanoacrylate embolization and radiofrequency ablation during a three-year period. Patient records were reviewed to assess demographics, location and severity of disease, treatment details and outcome at short- and mid-term follow-ups. Outcome parameters included treatment success and complications. Results Between January 2014 and December 2016, 335 patients with 476 veins were treated with either cyanoacrylate embolization (n = 148) or radiofrequency ablation (n = 328) at the Vancouver General Hospital Vascular Surgery Vein Clinic. The average age of patients were 57 ± 1 years with the majority being female (78%) and an average BMI of 24.8 ± 0.5. CEAP classes were 2 (49%), 3 (26%), 4a (22%) and >4b (3%). Of the veins treated with cyanoacrylate embolization, the vein types were as follows: 76% were great saphenous vein, 16% were small saphenous vein, 5% were anterior accessory great saphenous vein and 1.4% were perforator veins. The vein types for radiofrequency ablation were 88%, 9%, 3% and 0%, respectively. The average amount of cyanoacrylate embolization delivered for great saphenous vein treatment was 1.8 ± 0.1 ml with a treatment length of 43 ± 1 cm. Subgroup comparison was done for great saphenous vein segments. Treatment success was 100% in cyanoacrylate embolization and 99% in radiofrequency ablation. Superficial phlebitis was the most common complication noted at mid-term follow-up in 5% of cyanoacrylate embolization and 16% of radiofrequency ablation treatments (P < 0.05). One patient in each group had asymptomatic proximal thrombus extension treated with anticoagulation for 2–3 weeks. Three superficial infections from glue clumps were noted in the cyanoacrylate embolization group requiring excision and drainage. Five patients in the radiofrequency ablation group had persistent numbness and one wound complications at the access site. Conclusion Cyanoacrylate embolization offers equivalent success rates with lower mid-term complication rates as radiofrequency ablation.

An age-based comparison of fistula location, patency, and maturation for elderly renal failure patients

Objective: Current Kidney Disease Outcomes Quality Initiative guidelines do not incorporate age in determining autogenous arteriovenous hemodialysis access placement, and the optimal initial configuration in elderly patients remains controversial. We compared patency, maturation, survival, and complications between several age cohorts (<65 years, 65‐79 years, >80 years) to determine whether protocols should be modified to account for advanced age. Methods: All patients at two teaching hospitals undergoing a first autogenous arteriovenous access creation in either arm between 2007 and 2013 were retrospectively analyzed from a prospectively maintained database. Kaplan‐Meier survival and Cox hazards models were used to compare access patency and risk factors for failure. Results: There were 941 autogenous arteriovenous accesses (median follow‐up, 23 months; range, 0‐89 months) eligible for inclusion; 152 (15.3%) accesses were created in those >80 years, 397 (42.2%) in those 65 to 79 years, and 392 (41.8%) in those <65 years. Primary patencies in patients >80 years, 65 to 79 years, and <65 years were 40% ± 4%, 38% ± 3%, and 51% ± 3% at 12 months and 12% ± 5%, 13% ± 3%, and 27% ± 3% at 36 months (P < .001). Primary assisted patencies were 72% ± 4%, 70% ± 2%, and 78% ± 2% at 12 months and 52% ± 5%, 52% ± 3%, and 67% ± 3% at 36 months (P < .001). Secondary patencies were 72% ± 4%, 71% ± 2%, and 79% ± 2% at 12 months and 54% ± 5%, 55% ± 3%, and 72% ± 3% at 36 months (P < .001). Radiocephalic patencies were lowest among older cohorts; in those >80 years, 65 to 79 years, and <65 years, they were 65% ± 7%, 67% ± 4%, and 77% ± 3% at 12 months and 41% ± 8%, 51% ± 5%, and 68% ± 4% at 36 months (P = .019). Secondary brachiocephalic access patencies in these cohorts were 78% ± 5%, 80% ± 3%, and 82% ± 3% at 12 months and 68% ± 7%, 66% ± 5%, and 77% ± 4% at 36 months (P = .206). Both the age groups 65 to 79 years and >80 years demonstrated superior brachiocephalic vs radiocephalic secondary patencies (P = .048 and P = .015, respectively); however, no differences between configuration and secondary patency were observed within the cohort <65 years. Radiocephalic access maturation failure at 12 and 24 months was 25% ± 3% and 29% ± 4% in those <65 years, 32% ± 3% and 39% ± 4% in those 65 to 79 years, and 40% ± 7% and 48% ± 8% in those >80 years (P = .006). Brachiocephalic access maturation failures were 17% ± 3% and 20% ± 3% at 12 and 24 months in those <65 years, 21% ± 3% and 25% ± 4% in those 65 to 79 years, and 18% ± 5% and 21% ± 5% in those >80 years (P = .740). On multivariate analysis, coronary disease, female sex, previous ipsilateral or bilateral catheters, radiocephalic configuration, and age >65 years were associated with secondary patency loss. Conclusions: Patients aged 65 to 79 years and >80 years had inferior primary, primary assisted, and secondary patency and maturation compared with those <65 years. When stratified by configuration, radiocephalic accesses demonstrated lower patency and maturation compared with brachiocephalic accesses for patients aged 65 to 79 years and >80 years and were an independent predictor of secondary patency loss.

Endovascular Repair of Extent II-IV Thoracoabdominal Aortic Aneurysms

Two type II endoleaks were present but did not require reintervention. The composite outcome was achieved in 83% of cases (5 of 6). Conclusions: Off-the-shelf bifurcated-bifurcated aneurysm repairs for aortoiliac aneurysm disease can be safely and efficiently performed in a majority of cases to maintain IIA perfusion and to avoid pelvic ischemic complications. Attention should be directed at purpose-built bridging stents for the general purpose of branch vessel preservation. Comparison to historical controls with IIA embolization is warranted.

Standard Thoracic Endovascular Aortic Repair Compared With Provisional Extension to Induce Complete Attachment in Aortic Dissection

Objective: We compared the management of patients with symptomatic, unruptured aortic aneurysms (sxAAAs) treated at a tertiary care center between two decades. This 20-year period encapsulated a shift in surgical approach to aortic aneurysms from primarily open to primarily endovascular, and we sought to determine the impact, if any, of this shift. Methods: A consecutive 2380 patients treated at a tertiary care hospital by six staff surgeons were reviewed between 1995 and 2005 (period 1) and 2005 and 2015 (period 2). Of those patients, 156 (6.5%) were treated for sxAAAs and were included in our study. Patient demographics, operative approach, and outcomes were analyzed and compared for each period. Results: Period 1 included 72 patients treated for sxAAA (80.6% infrarenal, 15.3% juxtarenal, 2.8% thoracic aortic aneurysm type IV, and 1.8% endoleak after endovascular aneurysm repair); 70.8% of patients were treated with open repair, and 29.2% were treated with an endovascular repair. Period 1 patients had an average age of 74.9 6 9.4 years and were made up of 63.9% men. In-hospital mortality during this period was 4.2% (5.9% for open cohort and 0% for endovascular). Period 2 included 84 patients treated for sxAAA (72.6% infrarenal, 15.5% juxtarenal, 7.1% thoracic aortic aneurysm type IV, and 4.8% endoleak after endovascular aneurysm repair); 32.1% were treated with open repair, and 67.9% underwent endovascular repair. The average age in this cohort was 73.0 6 9.8 years, and 76.2% were men. In-hospital mortality was 1.2% (3.7% for open cohort and 0% for endovascular). Period 2 had a significantly higher rate of endovascular repair compared with period 1 (P < .0001) and a trend toward decreased mortality and increased aneurysm complexity. The length of hospital stay was significantly longer in the open cohort compared with endovascular for both periods (P < .02). Conclusions: To our knowledge, this is the largest singleinstitution cohort of symptomatic unruptured aortic aneurysms. As to be expected, we found a significant change in the approach to these patients from a primarily open to a primarily endovascular technique between decades, associated with decreased mortality and increased operative complexity. Overall, however, the incidence and mortality for both periods appear to be lower than previously published. Standard Thoracic Endovascular Aortic Repair Compared With Provisional Extension to Induce Complete Attachment in Aortic Dissection Kyle Arsenault, MD, Darren Klass, MD, Joel Price, Michael Janusz, Joel Gagnon, Jerry Chen, Jason Faulds. Vascular Surgery, University of British Columbia, Vancouver, British Columbia, Canada; University of British Columbia, Vancouver, British Columbia, Canada