Microcirculation surrounding end-stage human chronic skin wounds is associated with endoglin/CD146/ALK-1 expression, endothelial cell proliferation and an absence of p16Ink4a.

Angiogenesis is an essential part of normal skin healing, re-establishing blood flow in developing granulation tissue. Non-healing skin wounds are associated with impaired angiogenesis and although the role of re-establishing macroscopic blood flow to limbs to prevent wound chronicity is well investigated, less is known about vascular alterations at the microcirculatory level. We hypothesised that significant phenotypic changes would be evident in blood vessels surrounding chronic skin wounds. Wound edge tissue, proximal to wound (2 cm from wound edge) and non-involved skin (>10 cm from wound edge) was harvested under informed consent from 20 patients undergoing elective amputation due to critical limb ischemia. To assess blood vessel structure and viability, tissue was prepared for histological analysis and labelled with antibodies specific for PECAM-1 (CD31), CD146, endoglin, ALK-1, ALK-5, and p16Ink4a as a marker of cellular senescence. Density of microvasculature was significantly increased in wound edge dermis, which was concomitant with increased labelling for endoglin and CD146. The number of CD31 positive vessel density was unchanged in wound edge tissue relative to non-involved tissue. Co-labelling of endoglin with the transforming growth factor receptor ALK-1, and to a lesser extent ALK-5, demonstrated activation of endothelial cells which correlated with PCNA labelling indicative of proliferation. Analysis of p16Ink4a staining showed a complete lack of immunoreactivity in the vasculature and dermis, although staining was evident in sub-populations of keratinocytes. We conclude that the endoglin-ALK-1-endothelial proliferation axis is active in the vasculature at the edge of chronic skin wounds and is not associated with p16Ink4a mediated senescence. This information could be further used to guide treatment of chronic skin wounds and optimise debridement protocols.

A Novel Technique for Thoracic Endovascular Graft Explantation.

Thoracic endovascular aortic repair (TEVAR) explantation remains a challenge due to endovascular graft ingrowth into the aortic wall with time. Surgical access into the aortic arch can be difficult either via sternotomy or thoracotomy, and proximal barbs become engaged firmly into the aortic wall. Explantation often requires extensive thoracic aortic resection, sometimes from the distal aortic arch to the abdominal aorta, followed by reconstruction, risking injury to surrounding neurovascular structures and even death. In cases of blunt thoracic aortic injury, the original injury is often healed, and failed TEVAR could theoretically be removed when thrombotic complications occur. We present a novel technique to facilitate TEVAR recapture with limited distal thoracic aorta replacement.

Cushioned on the way up, controlled on the way down during resuscitative endovascular balloon occlusion of the aorta (REBOA): investigating a novel compliant balloon design for optimizing safe overinflation combined with partial REBOA ability.

Background: There are a variety of devices capable of performing resuscitative endovascular balloon occlusion of the aorta (REBOA), with most containing compliant balloon material. While compliant material is ideal for balloon inflation due to its "cushioning" effect, it can be problematic to "control" during deflation. The COBRA-OS (Control Of Bleeding, Resuscitation, Arterial Occlusion System) was designed to optimize inflation and deflation of its compliant balloon and was tested in vitro and in vivo with respect to its overinflation and partial REBOA abilities. Methods: For overinflation, the COBRA-OS was inflated in three differently sized inner diameter (ID) vinyl tubes until balloon rupture. It was then overinflated in six harvested swine aortas and in all three REBOA zones of three anesthetized swine. For partial REBOA, the COBRA-OS underwent incremental deflation in a pulsatile benchtop aortic model and in zone 1 of three anesthetized swine. Results: For overinflation, compared with the known aortic rupture threshold of 4 atm, the COBRA-OS exceeded this value in only the smallest of the vinyl tubes: 8 mm ID tube, 6.5 atm; 9.5 mm ID tube, 3.5 atm; 13 mm ID tube, 1.5 atm. It also demonstrated greater than 500% overinflation ability without aortic damage in vitro and caused no aortic damage when inflated to maximum inflation volume in vivo. For partial REBOA, the COBRA-OS was able to provide a titration window of between 3 mL and 4 mL in both the pulsatile vascular model (3.4±0.12 mL) and anesthetized swine (3.8±0.35 mL). Discussion: The COBRA-OS demonstrated the ability to have a cushioning effect during inflation combined with titration control on deflation in vitro and in vivo. This study suggests that despite its balloon compliance, both safe overinflation and partial REBOA can be successfully achieved with the COBRA-OS. Level of evidence: Basic science.

Malperfusion syndrome in acute type A aortic dissection: Thinking beyond the proximal repair.

BACKGROUND AND OBJECTIVE: Malperfusion syndrome (MPS) is associated with the highest mortality and major morbidity risk in patients with acute Type A aortic dissection (TAAD). The timing of the open proximal aortic repair in the presence of MPS remains debatable given variability in clinical presentation and different local treatment algorithms. This paper provides an up to date and comprehensive overview of published outcomes and available techniques for addressing malperfusion in the setting of acute TAAD. METHODS: We have reviewed published data from the major aortic dissection registries including the International Registry of Acute Aortic Dissection, the German Registry for Acute Aortic Dissection In Type A, and the Nordic Consortium for Acute Type A Aortic Dissection, as well as the most up to date literature involving malperfusion in the setting of acute TAAD. This data highlights unique strategies that have been adopted at aortic centers internationally to address malperfusion in this setting pre-, intra-, and postoperatively, which are summarized here and may be of great clinical benefit to other centers treating this disease with more traditional methods. RESULTS: The review of the available data has definitively shown an increased mortality up to 43% and morbidity in patients presenting with MPS in the setting of acute TAAD. More specifically, preoperative MPS has been shown to be an independent predictor of mortality with mesenteric malperfusion associated with the worst mortality outcomes from 70% to 100%. Addressing MPS pre or intraoperatively is associated with significantly reduced mortality outcomes down to 4%-13%. CONCLUSION: Adapting a dynamic and easily accessible diagnostic method for the comprehensive assessment of different forms of malperfusion (dynamic/static) and incorporating it within the surgical plan is the first step toward early diagnosis and prevention of malperfusion related complications.

Evaluation of the Use of Single- and Multi-Magnification Convolutional Neural Networks for the Determination and Quantitation of Lesions in Nonclinical Pathology Studies.

Digital pathology platforms with integrated artificial intelligence have the potential to increase the efficiency of the nonclinical pathologist's workflow through screening and prioritizing slides with lesions and highlighting areas with specific lesions for review. Herein, we describe the comparison of various single- and multi-magnification convolutional neural network (CNN) architectures to accelerate the detection of lesions in tissues. Different models were evaluated for defining performance characteristics and efficiency in accurately identifying lesions in 5 key rat organs (liver, kidney, heart, lung, and brain). Cohorts for liver and kidney were collected from TG-GATEs open-source repository, and heart, lung, and brain from internally selected R&D studies. Annotations were performed, and models were trained on each of the available lesion classes in the available organs. Various class-consolidation approaches were evaluated from generalized lesion detection to individual lesion detections. The relationship between the amount of annotated lesions and the precision/accuracy of model performance is elucidated. The utility of multi-magnification CNN implementations in specific tissue subtypes is also demonstrated. The use of these CNN-based models offers users the ability to apply generalized lesion detection to whole-slide images, with the potential to generate novel quantitative data that would not be possible with conventional image analysis techniques.

Size matters: first-in-human study of a novel 4 French REBOA device.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technique used for non-compressible torso hemorrhage. However, its current use continues to be limited and there is a need for a simple, fast, and low profile REBOA device. Our objective was to evaluate the feasibility of a novel 4 French REBOA device called the COBRA-OS (Control of Bleeding, Resuscitation, Arterial Occlusion System). METHODS: This study is the first-in-human feasibility trial of the COBRA-OS. Due to the difficulty of trialing the device in the trauma setting, we performed a feasibility study using organ donors (due to the potential usefulness of the COBRA-OS for normothermic regional perfusion) after neurological determination of death (NDD) prior to organ retrieval. Bilateral 4 French introducer sheaths were placed in both femoral arteries and the COBRA-OS was advanced up the right side and deployed in the thoracic aorta (Zone 1). Once aortic occlusion was confirmed via the left-sided arterial line, the device was deflated, moved to the infrarenal aorta (Zone 3), and redeployed. RESULTS: A total of 7 NDD organ donors were entered into the study, 71% men, with a mean age 46.6 years (range 26 to 64). The COBRA-OS was able to occlude the aorta in Zones 1 and 3 in all patients. The mean time of placing a 4 French sheath was 47.7 seconds (n=13, range 28 to 66 seconds). The mean time from skin to Zone 1 aortic occlusion was 70.1 seconds (range 58 to 105 seconds); mean balloon volumes were 15 mL for Zone 1 (range 13 to 20 mL) and 9 mL for Zone 3 (range 6 to 15 mL); there were no complications and visual inspection of the aorta in all patients revealed no injury. DISCUSSION: The COBRA-OS is a novel 4 French REBOA device that has demonstrated fast and safe aortic occlusion in this first-in-human feasibility study. LEVEL OF EVIDENCE: Level V, therapeutic.

Onyx versus coil embolization for the treatment of type II endoleaks.

OBJECTIVE: Little evidence is available supporting the optimal treatment of type II endoleaks associated with aortic sac growth. Previous studies have lacked comparisons between treatment methods and long-term follow-up. The purpose of the present study was to review our center's experience with the treatment of type II endoleaks comparing Onyx (a liquid embolization agent consisting of ethylene vinyl alcohol; Medtronic, Minneapolis, Minn) embolization and coil embolization. METHODS: A retrospective review of prospectively collected data from a vascular surgery database was performed to identify all patients who had undergone embolization of a type II endoleak for aortic sac growth after endovascular aneurysm repair from 2005 to 2018. The Onyx and coil embolization groups were compared using univariate statistics. RESULTS: A total of 58 patients had undergone 77 embolization procedures for type II endoleaks with either Onyx (27 patients; 37 procedures) or coils (31 patients; 40 procedures). The average aneurysm size at embolization was larger in the Onyx group (77.9 ± 15.1 mm) compared with coil embolization (73.4 ± 11.9 mm). The mean follow-up was 57 months for the Onyx group and 74 months for the coil embolization group. Of the 27 patients who had undergone Onyx embolization, 2 (7.4%) had required graft explantation compared with 5 of the 31 patients (16.1%) who had undergone coil embolization (P = .33). The results of the per-patient analysis showed that the coil embolization group had a significantly greater rate of the need for further reintervention compared with the Onyx group (55% vs 19%; P < .01). Clinical success was observed in 13 patients (48%) in the Onyx embolization group compared with 10 patients (32%) in the coil embolization group (P = .04). Two patients in each group had presented with secondary rupture of the aneurysm sac after attempted embolization. CONCLUSIONS: Type II endoleaks associated with sac growth treated with Onyx were less likely to require further reinterventions than were those treated with coil embolization. A trend was found toward a greater need for endovascular aneurysm repair explant after coil embolization. With a high rate of further reintervention and potential for sac rupture, diligent follow-up is required after attempted type II embolization, regardless of the technique used.

Using Deep Learning Artificial Intelligence Algorithms to Verify N-Nitroso-N-Methylurea and Urethane Positive Control Proliferative Changes in Tg-RasH2 Mouse Carcinogenicity Studies.

In Tg-rasH2 carcinogenicity mouse models, a positive control group is treated with a carcinogen such as urethane or N-nitroso-N-methylurea to test study validity based on the presence of the expected proliferative lesions in the transgenic mice. We hypothesized that artificial intelligence-based deep learning (DL) could provide decision support for the toxicologic pathologist by screening for the proliferative changes, verifying the expected pattern for the positive control groups. Whole slide images (WSIs) of the lungs, thymus, and stomach from positive control groups were used for supervised training of a convolutional neural network (CNN). A single pathologist annotated WSIs of normal and abnormal tissue regions for training the CNN-based supervised classifier using INHAND criteria. The algorithm was evaluated using a subset of tissue regions that were not used for training and then additional tissues were evaluated blindly by 2 independent pathologists. A binary output (proliferative classes present or not) from the pathologists was compared to that of the CNN classifier. The CNN model grouped proliferative lesion positive and negative animals at high concordance with the pathologists. This process simulated a workflow for review of these studies, whereby a DL algorithm could provide decision support for the pathologists in a nonclinical study.

Obstruction of Small Arterioles in Patients with Critical Limb Ischemia due to Partial Endothelial-to-Mesenchymal Transition.

Critical limb ischemia (CLI) is a hazardous manifestation of atherosclerosis and treatment failure is common. Abnormalities in the arterioles might underlie this failure but the cellular pathobiology of microvessels in CLI is poorly understood. We analyzed 349 intramuscular arterioles in lower limb specimens from individuals with and without CLI. Arteriolar densities were 1.8-fold higher in CLI muscles. However, 33% of small (<20 µm) arterioles were stenotic and 9% were completely occluded. The lumens were closed by bulky, re-oriented endothelial cells expressing abundant N-cadherin that uniquely localized between adjacent and opposing endothelial cells. S100A4 and SNAIL1 were also expressed, supporting an endothelial-to-mesenchymal transition. SMAD2/3 was activated in occlusive endothelial cells and TGFß1 was increased in the adjacent mural cells. These findings identify a microvascular closure process based on mesenchymal transitions in a hyper-TGFß environment that may, in part, explain the limited success of peripheral artery revascularization procedures.

Long-term outcomes comparing endovascular and open abdominal aortic aneurysm repair in octogenarians.

OBJECTIVE: Patients older than 80 years have significantly lower early mortality with endovascular aneurysm repair (EVAR) compared with open repair for abdominal aortic aneurysms (AAAs), but long-term results remain poorly studied. We analyzed the results of both emergent and elective AAA repair in patients aged 80 years or older who had at least 5 years of follow-up. METHODS: Retrospective review of a prospectively collected vascular surgery database was performed to identify all patients who underwent elective repair of an AAA between 2007 and 2012 and were 80 years of age or older at the time of surgery. Open and EVAR groups were compared using univariate statistics. RESULTS: The study cohort was composed of 314 patients 80 years of age or older (median, 83 years; interquartile range, 5 years) who underwent repair (96 open, 218 EVAR). The groups had similar comorbidities, except that EVAR patients were more likely to be male and open repair patients were more likely to have larger aneurysms. Compared with open repair, elective early postoperative mortality was significantly lower for EVAR patients (1% vs 14%; P < .001). Overall mean life expectancy was 5.9 years (EVAR, 5.8 years; open repair, 5.8 years; P = .98). The 1-year survival was significantly higher for EVAR (92.9%) than for open repair (84.1%; P = .02). The 2-year survival (EVAR, 83.4%; open repair, 74.6%; P = .07) and 5-year survival (EVAR, 57.8%; open repair, 60.3%; P = .98) did not differ between EVAR and open repair. Reintervention rates (EVAR, 18%; open repair, 2%; P = .05) were higher in the endovascular treatment group. CONCLUSIONS: EVAR results in an improved 1-year mortality in octogenarians compared with open repair, although 5-year survival is similar between the groups. With average life expectancies of >5 years and an 18% reintervention rate, diligent follow-up is required after EVAR even in elderly patients.

Incidence, natural course, and outcome of type II endoleaks in infrarenal endovascular aneurysm repair based on the ENGAGE registry data.

OBJECTIVE: The purpose of this study was to report the incidence, natural history, and outcome of type II endoleaks in the largest prospective real-world cohort to date. METHODS: Patients were extracted from the prospective Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE). Two groups were analyzed: first, patients with an isolated type II endoleak; and second, patients with a type II endoleak who later presented with a type I endoleak. A health status analysis between patients with an early type II endoleak and patients with no endoleak was performed. Second, an attempt was made to identify risk factors in patients with a type II endoleak who later presented with a type I endoleak. RESULTS: Through 5 years of follow-up, a total of 197 (15.6%) patients with isolated type II endoleaks were identified. Most were detected within the first 30 days (n = 73 [37.1%]) and through the first year (n = 73 [37.1%]), with the remainder being detected after 1 year of follow-up (n = 51 [25.8%]). Patients with a type II endoleak had a higher incidence of aneurysm growth and more secondary endovascular procedures (15.4% vs 7.5% at 5 years; P < .001). Overall survival was higher in the isolated type II endoleak group compared with patients with no endoleak (77.2% vs 67.0% at 5 years; P = .010). Twenty-two patients (10%) with a type II endoleak were diagnosed with a late type I endoleak (type IA, n = 10; type IB, n = 12), with a secondary intervention rate of 67.5% through 5 years. There was no difference in health status scores between patients with an early type II endoleak and patients without any type of endoleak at 1-year follow-up. CONCLUSIONS: In the ENGAGE registry, isolated type II endoleaks are present in 15.6% of patients during follow-up. The majority do not require secondary intervention, and an early isolated type II endoleak does not have an impact on health status through 1 year. However, a small group of patients with a type II endoleak will present with a type I endoleak, resulting in a high secondary intervention rate and significant risk of aneurysm-related complications.

Improvements in patient outcomes with next generation endovascular aortic repair devices in the ENGAGE Global Registry and the EVAR-1 clinical trial.

BACKGROUND: The outcomes from the randomized controlled trials (RCTs) comparing endovascular aortic aneurysm repair (EVAR) to open surgical repair (OSR) may no longer be reflective of currently technology. Here the EVAR-1 trial and the ENGAGE registry are examined to assess potential improvements in outcomes with modern stent graft systems. METHODS: EVAR-1 was a multicenter, prospective, randomized controlled trial in the UK and patients were enrolled between 1999 and 2004 and treated with first- and second-generation devices. ENGAGE is an observational, nonrandomized, prospective registry that completed enrollment between 2009 and 2011. All ENGAGE patients were treated with the Endurant AAA Stent Graft System. A descriptive comparison of the published four-year outcomes of all-cause mortality (ACM), aneurysm-related mortality (ARM), rupture after elective EVAR, and reinterventions are reported. RESULTS: Through the four-year timepoint, freedom from ACM was 74.4% in the EVAR-1 Trial and 74.6% in the ENGAGE registry. ARM in the EVAR-1 trial was 4.2% and in the ENGAGE registry was 1.9%. Death due to rupture through four years was 1.6% (10/626) and 0.5% (6/1263) in the EVAR-1 and ENGAGE patients, respectively. In the EVAR-1 trial, the proportion of patients requiring at least one reintervention through the four-year timepoint was 19.3% (121/626) whereas in the ENGAGE registry, reinterventions occurred in 10.9% (138/1263) of patients. CONCLUSIONS: EVAR patient outcomes have improved since the time of the original EVAR vs. OSR trials and data from real-world registries should be considered a primary resource for developing new guidelines for patient selection and management.

Vascular trauma: Does experience in the United States apply to a Canadian centre?

Summary: Trauma care has evolved similarly in the United States and Canada over the last 3 decades. Like much of modern trauma care, management of vascular trauma has been influenced by combat surgery experiences in recent wars. The American Association for the Surgery of Trauma sponsored the Prospective Observational Vascular Injury Treatment (PROOVIT) registry to document changes in the treatment of vascular trauma and determine outcomes in the US. However, differences in trauma populations and trauma systems between Canada and the US need to be considered. Here we compare the vascular trauma experience at a Canadian level I trauma centre over a 5-year period to the data in the PROOVIT registry.

Vascular surgery resident training in Canada.

The training of vascular surgeons in Canada has evolved over the past decade. Direct entry into a vascular surgery training program after medical school has been offered since 2012. At some institutions, it is the only option for surgery training. The smaller population of Canada and a single-payer health care system has resulted in unique opportunities and challenges for the training of vascular surgeons and providing opportunities for trainees to transition into clinical practice.

Editor's Choice - Five Year Outcomes of the Endurant Stent Graft for Endovascular Abdominal Aortic Aneurysm Repair in the ENGAGE Registry.

OBJECTIVE/BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) is commonly used to treat abdominal aortic aneurysm (AAA). However, the incidence of long-term complications and the need for re-interventions after EVAR remain a concern. Newer generation stent grafts have encouraging short and mid-term outcomes, but thorough analysis of their long-term performance is necessary. METHODS: The ENGAGE registry includes a total of 1263 patients with AAA enrolled from March 2009 to April 2011 at 79 centres across 30 countries. The aim of this study is to present standard EVAR outcomes in the registry after five years. RESULTS: A significant proportion of the ENGAGE patients presented with challenging features, such as 15.2% with an AAA diameter >7 cm, 12.0% with proximal neck lengths <15 mm, and 10.2% with infrarenal neck angles >60°. Of the 1263 enrolled subjects, 17.8% were implanted outside of the instructions for use for the device. At the five year follow up, the Kaplan-Meier overall survival rate was 67.4% and the freedom from aneurysm related mortality was 97.8%. Freedom from aneurysm rupture, secondary procedures, and conversion to open repair at five years were 98.6%, 84.3%, and 97.9% respectively. The five year freedom from type IA endoleaks was 95.2% and for type III endoleaks 97.4%. Aneurysm sac diameter at five years was observed to have either decreased ≥5 mm in diameter or remained stable in 89.4% of the patients. CONCLUSION: Five year follow up of patients in the ENGAGE registry demonstrates sustained safety, effectiveness, and durability in an international cohort that is reflective of real world experience. Additional follow up is expected through to 10 years.

Editor's Choice - Infrainguinal Bypass Following Failed Endovascular Intervention Compared With Primary Bypass: A Systematic Review and Meta-Analysis.

OBJECTIVES: Patients with infrainguinal peripheral arterial disease often undergo multiple revascularisation procedures. Although many centres have adopted an endovascular first approach, some are reluctant to do so for fear of compromising the outcomes of any subsequent bypasses. All studies that compared the outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention were analysed. METHODS: A systematic review was conducted of MEDLINE, EMBASE, and CENTRAL databases for studies comparing outcomes of primary infrainguinal bypass with bypass after failed endovascular intervention for peripheral arterial disease. Abstracts and full text studies were screened independently by two reviewers with data abstraction done in duplicate. Dichotomous outcome measures were reported using the OR and 95% CI, and pooled using random effects models. RESULTS: Abstracts were screened (2,528), with 50 selected for full text review. Of these, 15 studies involving 11,886 patients met the inclusion criteria. Pooling the results of studies comparing primary bypass with bypass after failed endovascular intervention showed no significant difference in 30 day mortality (OR 1.00; 95% CI 0.65-1.54), or 30 day amputation rates (OR 1.26; 95% CI 0.95-1.65). Interestingly, one year amputation free survival was higher in the patients who had primary bypass (OR 1.30; 95% CI 1.10-1.52) compared with patients who had bypass after failed endovascular therapy. There was also worse one year primary patency (OR 1.65; 95% CI 1.04-2.62) for patients with prior failed endovascular intervention. The review demonstrated a trend towards higher rates of early graft occlusion (OR 4.54; 95% CI 0.97-21.28). CONCLUSIONS: Meta-analysis of the existing literature comparing primary bypass with bypass following failed endovascular intervention shows worse one year amputation free survival and worse primary patency in those patients who undergo bypass after failed endovascular intervention. There is also a trend towards higher rates of early graft occlusion, although these results were not statistically significant. These conclusions are limited by observational study design, inconsistent patient selection, and significant heterogeneity between studies.

Management of the difficult left subclavian artery during aortic arch repair.

Management of the left subclavian artery (SCA) during aortic arch surgery is associated with several challenges, including preserving distal perfusion, achieving hemostasis and preventing posterior circulation stroke and spinal cord injury. The most common challenge remains its deep position in the chest, often exacerbated by posterior and apical displacement from an arch aneurysm. We discuss several management options consisting of pre-, intra- and post-operative strategies and their respective advantages, disadvantages and clinical outcomes. A clinical algorithm is proposed to help guide decision-making in managing the difficult left SCA during aortic arch repair.

Patient satisfaction with the consent discussion is not improved by showing patients their computed tomography or angiography images before they undergo vascular surgery.

OBJECTIVE: Patient-based decision aids and other multimedia tools have been developed to help enrich the preoperative discussion between surgeon and patient. Use of these tools, however, can be time-consuming and logistically challenging. We investigated whether simply showing patients their images from preoperative computed tomography (CT) or angiography would improve patients' satisfaction with the preoperative discussion. We also examined whether this improved the patient's understanding and trust and whether it contributed to increased preoperative anxiety. METHODS: Patients undergoing either elective abdominal aortic aneurysm repair or lower limb revascularization were randomly assigned to either standard perioperative discussion or perioperative discussion and review of images (CT image or angiogram). Randomization was concealed and stratified by surgeon. Primary outcome was patient satisfaction with the preoperative discussion as measured by a validated 7-item scale (score, 0-28), with higher scores indicating improved satisfaction. Secondary outcomes included patient understanding, patient anxiety, patient trust, and length of preoperative discussion. Scores were compared using t-test. RESULTS: Overall, 51 patients were randomized, 25 to the intervention arm (discussion and imaging) and 26 to the control arm. Most patients were male (69%), and the average age was 70 years. Forty percent of patients underwent abdominal aortic aneurysm repair, whereas 60% underwent lower limb revascularization. Patient satisfaction with the discussion was generally high, with no added improvement when preoperative images were reviewed (mean score, 24.9 ± 3.02 vs 24.8 ± 2.93; P = .88). Similarly, there was no difference in the patient's anxiety, level of trust, or understanding when the imaging review was compared with standard discussion. There was a trend toward longer preoperative discussions in the group that underwent imaging review (8.18 vs 6.35 minutes; P = .07). CONCLUSIONS: Showing patients their CT or angiography images during the preoperative discussion does not improve the patient's satisfaction with the consent discussion. Similarly, there was no effect on the patient's trust, understanding, or anxiety level. Our conclusions are limited by the lack of a standardized measure of patient understanding and not measuring outcomes postoperatively, both of which should be considered in future studies.

Preoperative point-of-care ultrasound and its impact on arteriovenous fistula maturation outcomes.

OBJECTIVE: Duplex ultrasound as a preoperative assessment tool in the clinic may help identify anatomic factors predictive of fistula maturation. Preoperative point-of-care ultrasound (POCUS) offers surgeons an alternative to routine formal vein mapping as it can be performed by the operator during the initial clinic visit. We sought to determine the impact of POCUS as an adjunct to physical examination on arteriovenous fistula maturation. METHODS: All consecutive patients undergoing first-time dialysis access creation from December 2007 to December 2014 were retrospectively reviewed. Surgeons who routinely use POCUS to assess preoperative maximal vein diameter and quality were compared with surgeons who relied only on physical examination. All access and patency definitions were in accordance with the Society for Vascular Surgery's reporting standards. The effects of POCUS on fistula maturation rate and fistula abandonment were analyzed using logistic regression, controlling for comorbidities of the patient, anticoagulant use, and location of fistula. RESULTS: A total of 316 patients were included in the study; 250 patients were assessed exclusively with physical examination, and 66 patients underwent preoperative ultrasound examination by the vascular surgeon in the clinic. The primary failure rate in the ultrasound group was 18% compared with 47% (P < .001) in the group of patients who did not undergo ultrasound examination. In patients without preoperative ultrasound, there were higher rates of new access creation (31% vs 9%; P < .001) and fistula abandonment (66% vs 39%; P < .001). Multivariable analysis demonstrated that fistulas created without preoperative ultrasound were associated with a 3.56 greater risk of failure (95% confidence interval, 1.67-7.59; P = .001) compared with fistulas in the POCUS group. Similarly, the rate of fistula abandonment was 2.63 times higher (95% confidence interval, 1.38-5.05; P = .003) when ultrasound was not used preoperatively. Time to functional fistula maturation was better in the ultrasound group (P < .001). At 1 year, 12% of fistulas in the ultrasound group and 32% in the clinical examination group had yet to be cannulated. Secondary patency at 1 year was better in the POCUS group at 73% compared with 59% in the group with no preoperative ultrasound (P = .01). CONCLUSIONS: POCUS as an adjunct to physical examination for dialysis access patients leads to decreased rates of primary failure, new access creation, and fistula abandonment compared with patients who undergo only physical examination. Ultrasound examination improved times to functional fistula maturation and secondary patency. Further studies are required to compare POCUS with formal preoperative vein mapping for arteriovenous fistula planning.