The Emotional Impact and Coping Mechanisms Following Adverse Patient Events Among Canadian Vascular Surgeons and Trainees.

BACKGROUND: This study's objective is to evaluate the emotional experiences, coping mechanisms, and support resources for Canadian vascular surgeons and trainees following an adverse patient event or near miss. METHODS: This is a cross-sectional survey study of all Canadian Society for Vascular Surgery (CSVS) members from October to November 2021. We collected data on participant experiences with adverse events, their emotional responses, the coping mechanisms used, and their perceptions on available support resources. RESULTS: The survey was sent to 233 CSVS members yielding 66 responses. The majority (77%) of respondents had experiences with adverse event causing serious patient harm. The most common negative experience following an adverse event included feelings of negativity towards oneself, general distress, and anxiety about potential for future errors. The most common coping mechanism was seeking advice from a mentor or close colleague. Peers (82%) and senior colleagues (59%) were the most preferred sources of support. Most of the respondents would reach out to a mentor if they had 1, but 30% reported no mentor or close colleague for support. CONCLUSION: Adverse patient events and near misses have serious negative impact on the lives of Canadian vascular surgeons and trainees. Peers and senior colleagues are the most desired source for support, but this is not universally available. Organized efforts are needed to bring awareness in our vascular surgery community on the ubiquitous nature and detrimental effects of adverse events.

Evaluation of hydrophilic polymer embolization from endovascular sheath devices in an in vitro perfusion system.

Objective: Case reports, tissue pathology, and autopsies have suggested that the hydrophilic polymer coating designed to improve endovascular deliverability and minimize vessel trauma can embolize and be associated with adverse outcomes such as ischemia, infarction, and death. This study sought to determine whether hydrophilic polymers shed off commercially available sheaths in a controlled in vitro environment, with the hypothesis that significant differences between coated and uncoated (control) sheaths would be found. Methods: Six sheaths from each manufacturer, including Zenith Alpha abdominal endovascular stent grafts (Cook Medical), DrySeal sheaths (W.L. Gore & Associates), and Sentrant Introducer sheaths (Medtronic), were tested in an in vitro environment. Noncoated Check-Flo performer introducer sheaths (Cook Medical) were used as controls. Each test circuit ran for 150 minutes at an output of 3 L/min, the circuit was then drained and the fluid collected. Quantitative analysis included weighing the dried filter paper and using particle size light scattering to quantify the particle size and count. Attenuated total reflectance spectroscopy was also used. Results: Each of the three coated sheaths had significantly greater shedding compared with the control sheaths. The Cook Zenith alpha sheath had significantly more residue weight (2.87 ± 0.52 mg/L) than the Gore DrySeal (1.07 ± 0.06 mg/L) and Medtronic Sentrant introducer (0.98 ± 0.14 mg/L) sheaths. The average particle size was not significantly different between the coated and uncoated (control) sheaths. Attenuated total reflectance spectroscopy identified sheath particulate in the Cook Zenith Alpha and Medtronic Sentrant samples. Conclusions: Polymer embolization was present and significantly greater in all three commercially available hydrophilic sheaths compared with the control group. Further investigation is needed into the clinical significance of these findings.

Evaluation of factors associated with limb thrombus formation after endovascular aortic aneurysm repair.

BACKGROUND: Limb thrombus formation is a complication that can occur after endovascular aortic repair (EVAR), and its clinical significance has continued to be debated. Our objective was to report the incidence of limb thrombus after EVAR and determine the association of specific demographic, anatomic, and/or graft variables. METHODS: A retrospective analysis of EVAR patients at a single tertiary center between January 2010 and December 2018 was performed to determine the limb thrombus rate. Demographic, graft, and anatomic variables were analyzed for an association with limb thrombus. RESULTS: A total of 301 patients were included. The average follow-up was 27.6 ± 4.9 months. The mean age was 76.5 ± 0.5 years, and 85% were men. Limb thrombus occurred in 22 patients (7.3%). Of these 22 patients, 11 (50.0%) had had occlusive limb thrombus, 14 (63.6%) were symptomatic, and 17 (77.3%) had required intervention. The patients with limb thrombus were younger (69.8 ± 1.3 years vs 77.1 ± 0.5 years; P < .0001) and more likely to be smokers (10.2% vs 5.2%; P = .10). The incidence of limb thrombus with the Alpha graft (10.7%; Cook Medical Inc, Bloomington, IN) was compared with that with non-Cook grafts (4.0%; P = .07). The average common iliac artery diameter for patients with and without limb thrombus was 14.1 mm and 16.1 mm, respectively (P < .01). Right-sided limb thrombus was more likely in smaller right iliac arteries (14.7 ± 0.9 cm vs 17.0 ± 0.6 cm; P < .05), with a similar finding on the left (13.6 ± 0.9 cm vs 15.2 ± 0.4 cm; P = .13). Unilateral limb thrombus was almost twice as likely on the main body side than on the contralateral side (11 vs 6). Limb thrombus was not associated with aortoiliac disease (odds ratio [OR], 1.31; 95% confidence interval [CI], 0.37-4.62), limb extension (OR, 0.47; 95% CI, 0.06-3.62), or nonmatching limb heights (OR, 1.36; 95% CI, 0.54-3.43). Limb thrombus was also not associated with increased 30-day mortality (P > .05). CONCLUSIONS: Limb thrombus formation is a complication that can occur after EVAR (7.3%). In our study, limb thrombus was seen more frequently in younger patients and those who smoked. Cook Alpha grafts had a thrombus formation rate of 10.7%, which was not significantly higher than that with other brands. Limb thrombus was more likely in smaller iliac arteries and on the main body side.

Gonadal vein as a bypass conduit for arterial reconstruction during an aortic debranching repair of a paravisceral aortic aneurysm.

We report a case of a hybrid aortic debranching procedure for repair of a paravisceral inflammatory aortic aneurysm. Vein grafts were chosen over prosthetics because of concern for infection as a possible etiology. The gonadal vein was successfully used as a vein graft between the right common iliac artery and the right renal artery before aortic endograft placement.

Ultrasound-guided cyanoacrylate injection for the treatment of incompetent perforator veins.

OBJECTIVE: The use of cyanoacrylate products (CA) in incompetent perforator vein (IPV) treatment has not been thoroughly examined. The primary objective of this study is to describe the technique of ultra sound guided direct injection of IPV with CA, and secondarily to determine early closure rates and safety of this technique. METHODS: A retrospective analysis of patients undergoing IPV injection at two centres between 2015-2018 was conducted. Demographics, CEAP classification and IPV location were collected. Outcomes were assessed at two follow-up appointments. RESULTS: A total of 83 perforator vein injections were completed. CEAP classifications include C2 - C6 classes. Location of perforators were posteromedial (6%), femoral canal (9%), paratibial (14%), and posterior-tibial (71%). IPV closure rates were 96.3% at initial follow-up (16 ± 2 days). Closure rates decreased to 86.5% at second follow-up (72 ± 9 days). There were no deep vein thromboses during follow-up. One patient developed septic thrombophlebitis that was successfully managed with antibiotics. CONCLUSION: Ultrasound-guided CA glue injection is a simple and low risk procedure that effectively closes incompetent perforator veins.

A Canadian multicenter experience describing outcomes after endovascular abdominal aortic aneurysm repair stent graft explantation.

BACKGROUND: Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant. METHODS: The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation. RESULTS: Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation. CONCLUSIONS: The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes.

Cost-minimization study of the percutaneous approach to endovascular aortic aneurysm repair.

OBJECTIVE: Percutaneous access for endovascular aortic aneurysm repair (P-EVAR) is less invasive compared with surgical access for endovascular aortic aneurysm repair (S-EVAR). P-EVAR has been associated with shorter recovery and fewer wound complications. However, vascular closure devices (VCDs) are costly, and the economic effects of P-EVAR have important implications for resource allocation. The objective of our study was to estimate the differences in the costs between P-EVAR and S-EVAR. METHODS: We used a decision tree to analyze the costs from a payer perspective throughout the course of the index hospitalization. The probabilities, relative risks, and mean difference summary measures were obtained from a systematic review and meta-analysis. We modelled differences in surgical site infection, lymphocele, and the length of hospitalization. Cost parameters were derived from the 2014 National Inpatient Sample using "International Classification of Diseases, 9th Revision, Clinical Modification" codes. Attributable costs were estimated using generalized linear models adjusted by age, sex, and comorbidities. A sensitivity analysis was performed to determine the robustness of the results. RESULTS: A total of 6876 abdominal and thoracic EVARs were identified. P-EVAR resulted in a mean cost savings of $751 per procedure. The mean costs for P-EVAR were $1287 (95% confidence interval [CI], $884-$1835) and for S-EVAR were $2038 (95% CI, $757-$4280). P-EVAR procedures were converted to open procedures in 4.3% of the cases. The P-EVAR patients had a difference of -1.4 days (95% CI, -0.12 to -2.68) in the length of hospitalization at a cost of $1190/d (standard error, $298). The cost savings of P-EVAR was primarily driven by the cost differences in the length of hospitalization. In the base case, four VCDs were used per P-EVAR at $200/device. In the two-way sensitivity analysis, P-EVAR resulted in cost savings, even when 1.5 times more VCDs had been used per procedure and the cost of each VCD was 1.5 times greater. In our probabilistic sensitivity analysis, P-EVAR was the cost savings strategy for 82.6% of 10,000 Monte Carlo simulations when simultaneously varying parameters across their uncertainty ranges. CONCLUSIONS: P-EVAR had lower costs compared with S-EVAR and could result in dramatic cost savings if extrapolated to the number of aortic aneurysms repaired. Our analysis was a conservative estimate that did not account for the improved quality of life after P-EVAR.

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.

A vascularized and perfused organ-on-a-chip platform for large-scale drug screening applications.

There is a growing awareness that complex 3-dimensional (3D) organs are not well represented by monolayers of a single cell type - the standard format for many drug screens. To address this deficiency, and with the goal of improving screens so that drugs with good efficacy and low toxicity can be identified, microphysiological systems (MPS) are being developed that better capture the complexity of in vivo physiology. We have previously described an organ-on-a-chip platform that incorporates perfused microvessels, such that survival of the surrounding tissue is entirely dependent on delivery of nutrients through the vessels. Here we describe an arrayed version of the platform that incorporates multiple vascularized micro-organs (VMOs) on a 96-well plate. Each VMO is independently-addressable and flow through the micro-organ is driven by hydrostatic pressure. The platform is easy to use, requires no external pumps or valves, and is highly reproducible. As a proof-of-concept we have created arrayed vascularized micro tumors (VMTs) and used these in a blinded screen to assay a small library of compounds, including FDA-approved anti-cancer drugs, and successfully identified both anti-angiogenic and anti-tumor drugs. This 3D platform is suitable for efficacy/toxicity screening against multiple tissues in a more physiological environment than previously possible.

Canadian experience with percutaneous endovascular aneurysm repair: short-term outcomes.

BACKGROUND: To decrease the morbidity associated with cut-downs during endovascular aneurysm repair, some authors have suggested the totally percutaneous endovascular repair (PEVAR). The goal of this report is to evaluate and describe our centre's experience with the total percutaneous endovascular aneurysm repair (PEVAR) for aortic abdominal aneurysm (AAA). METHODS: We performed a retrospective analysis of 15 consecutive patients with AAA, including 1 with right common iliac artery aneurysm. RESULTS: There were 12 men and 3 women with a mean age of 74 (standard deviation [SD] 2) years who underwent PEVAR with a Perclose ProGlide suture-mediated closure system between July 2007 and July 2008. All surgeries were elective. Forty percent of patients had a history of smoking, 73% were hypertensive, 33% were diabetic, 20% had chronic obstructive pulmonary disease and 40% had coronary artery disease. Fourteen patients had bilateral deployment for bifurcated devices (7 bifurcated Gore Excluder, 7 bifurcated Cook Zenith grafts), and 1 patient had unilateral deployment for a Cook Zenith device. The outer diameter of the sheaths used for puncture sites was on average 18.1-Fr (SD 0.6), with main bodies being 21.1-Fr (SD 0.3) and contralateral sides 15-Fr (SD 0.3). Procedural success was 93%, with 1 patient requiring a femoral artery cut-down because of failure of the Perclose device to deploy in the groin. Another patient had persistent venous bleeding in 1 puncture site that stopped with skin suturing. Endovascular aneurysm repair was 100% with no conversion to open surgery and no type-I endoleaks. The mean length of stay in hospital was 2.2 (SD 0.4) days. There were no long-term groin complications at 6 (SD 1) months' follow-up. CONCLUSION: To our knowledge, this is the first Canadian report of experience with PEVAR using the Perclose device. The technique is safe, reliable and allows discharge of patients soon after surgery.

Optical detection of terahertz using nonlinear parametric upconversion.

We extend our work to perform sensitive, room-temperature optical detection of terahertz (THz) by using nonlinear parametric upconversion. THz radiation at 700 GHz is mixed with pump light at 1,550 nm in a bulk GaAs crystal to generate an idler wave at 1,555.6 nm. The idler is separated, coupled into optical fiber, and detected using a gated Geiger-mode avalanche photodiode. The resulting THz detector has a power sensitivity of 4.5 pW/Hz and a timing resolution of 1 ns.

Optical detection of terahertz radiation by using nonlinear parametric upconversion.

We describe and demonstrate sensitive room-temperature detection of terahertz (THz) radiation by nonlinearly upconverting terahertz to the near-infrared regime, relying on telecommications components. THz radiation at 700 GHz is mixed with pump light at 1550 nm in a bulk GaAs crystal to generate an idler wave at 1555.6 nm, which is separated and detected by using a commercial p-i-n diode. The THz detector operates at room temperature and has an intrinsic THz-to-optical photon conversion efficiency of 0.001%.

Venovenostomy for outflow venous obstruction in patients with upper extremity autogenous hemodialysis arteriovenous access.

Outflow venous obstruction is a common problem in patients with autogenous upper extremity hemodialysis access. Surgical revision to divert blood flow into the patent vein is sometimes possible to restore unobstructed flow. The result of this type of procedure is not yet well known. The purpose of this report is to describe our experience with outflow venovenostomy (VV) to salvage dysfunctional autogenous upper extremity arterial venous access (AVF) threatened by venous outflow obstruction in hemodialysis-dependent patients. All patients who underwent VV procedures between September 1999 and October 2004 were reviewed. Data regarding patient demographics, comorbidities, procedure indications, perioperative complications, as well as postoperative AVF function and patency were gathered from patient charts and dialysis records. A total of 11 patients underwent VV in the study period. The median age of the AVF prior to VV was 14 months, with a range of 4-45 months. Two patients had radial cephalic AVF, and they had VV done in the antecubital fossa. Nine patients had brachial cephalic AVF. Seven of them underwent cephalic vein transposition VV, while two patients had basilic vein transposition. Functional AVF was achieved after 1 month in 10 out of 11 patients. Five patients had no further access interventions, four patients required angioplasty at the VV site to maintain access function, and one patient had access infection requiring surgical revision during follow-up. One patient never achieved access function. Postintervention assisted functional patency was 90% +/- 9.5% at 39 months. Median follow-up after VV was 16 months. Outflow VV is a viable surgical option for selected patients with failing AVF due to venous outflow obstruction.

Endovascular repair of a ruptured renal artery aneurysm.

PURPOSE: To describe the percutaneous treatment of a ruptured renal artery aneurysm (RAA) using a stent-graft. CASE REPORT: An 86-year-old woman had sudden onset of right-sided back pain and a swollen left leg. Computed tomography disclosed a right retroperitoneal mass involving the kidney; the inferior vena cava was compressed, with thrombus in the left common iliac artery. There was a suggestion of RAA associated with contrast extravasation. Angiography confirmed a saccular aneurysm of the distal right main renal artery immediately proximal to the first segmental branch. A Jostent peripheral stent-graft was implanted with complete exclusion of the lesion. At 6-month follow-up, the patient remained asymptomatic, but there was a suggestion of in-stent restenosis, which is being followed closely. CONCLUSIONS: In elderly patients who are hemodynamically stable and have aneurysm anatomy that is suitable for stent-graft placement, the endovascular approach may allow rapid and definitive treatment of the hemorrhage.