Leveraging Artificial Intelligence to Optimize the Care of Peripheral Artery Disease Patients.

Peripheral artery disease is a major atherosclerotic disease that is associated with poor outcomes such as limb loss, cardiovascular morbidity, and death. Artificial intelligence (AI) has seen increasing integration in medicine, and its various applications can optimize the care of peripheral artery disease (PAD) patients in diagnosis, predicting patient outcomes, and imaging interpretation. In this review, we introduce various AI applications such as natural language processing, supervised machine learning, and deep learning, and we analyze the current literature in which these algorithms have been applied to PAD.

Analysis of Extracranial Cerebrovascular Injuries: Clinical Predictors of Management and Outcomes.

BACKGROUND: Optimal management of traumatic extracranial cerebrovascular injuries (ECVIs) remains undefined. We sought to evaluate the factors that influence management and neurologic outcomes (stroke and brain death) following traumatic ECVI. METHODS: A retrospective review of a single level 1 trauma center's prospectively maintained data registry of patients older than 18 years of age with a diagnosis of ECVI was performed from 2013 to 2019. Injuries limited to the external carotid artery were excluded. Patient demographics, type of injury, timing of presentation, Biffl Classification of Cerebrovascular Injury Grade, Injury Severity Score (ISS), and Abbreviated Injury Scale were documented. Ultimate treatments (medical management and procedural interventions) and brain-related outcomes (stroke and brain death) were recorded. RESULTS: ECVIs were identified in 96 patients. The primary mechanism of injury was blunt trauma (89.5% vs. 10.5%, blunt versus penetrating), with 70 cases (66%) of vertebral artery injury and 37 cases of carotid artery injury. Treatments included vascular intervention (6.5%) and medical management (93.5%). Overall outcomes included ipsilateral ischemic stroke (29%) and brain death (6.5%). In the carotid group, vascular intervention was associated with higher Biffl grades (mean Biffl 3.17 vs. 2.23; P = 0.087) and decreased incidence of brain death (0% vs. 19%, P = 0.006), with no difference seen in ISS scores. Brain death was associated with higher ISS scores (40.29 vs. 24.17, P = 0.01), lower glascow coma score on arrival (3.57 vs. 10.63, P < 0.001), and increased rates of ischemic stroke (71% vs. 30%, P = 0.025). In the vertebral group, neither Biffl grade nor ISS were associated with treatment or outcomes. Regarding the timing of stroke in ECVI, there was no significant difference in the time from presentation to cerebral infarction between the carotid and vertebral artery groups (24.7 hr vs. 21.20 hr, P = 0.739). After this window, 98% of the ECVI cases demonstrated no further aneurysmal degeneration or new neurological deficits beyond the early time period (mean follow-up 9.7 months). CONCLUSIONS: Blunt cerebrovascular injuries should be viewed distinctly in the carotid and vertebral territories. In cases of injury to the carotid artery, Biffl grade and ISS score are associated with surgical intervention and neurologic events, respectively; vertebral artery injuries did not share this association. Neurologic deficits were detected in a similar time frame between the carotid artery and the vertebral artery injury groups and both groups had rare late neurologic events.

The Order of Operative Repair Does Not Influence Outcomes in Patients with Concomitant Popliteal Artery and Orthopedic Injuries.

BACKGROUND: The most challenging lower extremity traumatic injuries involve concomitant vascular and orthopedic injuries with amputation rates approaching 50%. Controversy exists as to how to prioritize the vascular and orthopedic repairs. We reviewed patients with popliteal artery and lower extremity orthopedic injuries to analyze the sequence of the vascular and orthopedic repairs on outcomes. METHODS: All adult patients with a diagnosis of concomitant popliteal artery and lower extremity fracture or dislocation were identified through a review of an institutional trauma registry performed at a level 1 trauma center from 2014 to 2019. Patient demographics, timing of presentation, injury severity score (ISS), surgical interventions, and limb outcome data were collected and examined. The sequence of operative repairs and factors influencing the operative order were analyzed. RESULTS: Twenty-nine patients were treated for popliteal artery injuries. Twelve of these 29 patients had concomitant popliteal artery and orthopedic fractures requiring surgical repair. Injury mechanisms included both blunt (50%, 6/12) and penetrating trauma (50%, 6/12); the majority involved femur fractures (58%, 7/12). Vascular repair included arterial bypass (75%, 9/12) or interposition grafts (25%, 3/12). Orthopedic repair included external fixation (83%, 10/12) and open reduction internal fixation (17%, 2/12). Vascular repair was performed first in 7/12 limbs (58%). Patients having vascular repair first had a trend toward lower blood pressure on arrival (P = 0.068). There was no significant difference in emergency department to operating room (OR) time, OR time, ISS, mangled extremity severity score, estimated blood loss, or blood transfusion for the sequence of operative repair. Fasciotomy was nearly ubiquitous, present in 11/12 patients (92%). There were no graft complications related to orthopedic manipulation, and there were no reported limb-length to graft-length discrepancies. Early limb salvage trended lower in the cohort with revascularization first (71% vs. 100%, P = 0.19). Of the remaining limbs available for follow-up, limb salvage at 4.25 years is 100%. CONCLUSIONS: In this small study of patients with concomitant lower extremity popliteal artery and orthopedic injuries, the order of operative repair does not appear to influence the success of revascularization.

Medical Management of Traumatic Vertebral Artery Injury Is Safe Regardless of the Severity of Injury.

BACKGROUND: Management of traumatic vertebral artery injury (VAI) remains under debate. Current consensus reserves surgical or endovascular management for high-grade injury in order to prevent stroke. We sought to evaluate the factors that influence posterior fossa stroke outcomes following traumatic VAI. METHODS: A search of the prospectively maintained PROOVIT trauma registry of patients older than 18 years of age with a diagnosis of VAI was performed at a level 1 trauma center from 2013 to 2019. Patient demographics, type of injury, the timing of presentation, Biffl Classification of Cerebrovascular Injury Grade score, medical management, procedural interventions, and stroke outcomes were analyzed. RESULTS: VAIs were identified in 66 trauma patients were identified out of 14,323 patients entered into the PROOVIT registry. The dominant mechanism was blunt injury (91.5% vs. 8.5%, blunt versus penetrating). Nine patients presented with symptomatic ipsilateral posterior circulation strokes visible on imaging. The average Biffl classification grade was similar between the stroke and nonstroke groups (2.0 vs. 1.5; P = 0.39). The average injury severity score (ISS) between stroke and nonstroke groups was also similar (9.0 vs. 14.0; P = 0.35). All 9 patients in the stroke group had magnetic resonance imaging verification of their infarct within an average of 21.2 hr from presentation. In the stroke group, 1 patient underwent diagnostic angiography but had no intervention. In the nonstroke group, all were treated with medical management alone and none underwent vertebral artery intervention. During a mean follow-up of 14.5 months, no patients experienced a new neurological deficit. CONCLUSIONS: The severity of VAI by Biffl grading and ISS are not associated with ischemic stroke at presentation following VAI. Medical management of VAI appears safe regardless of Biffl and ISS staging in this trauma population. Neurological changes related to embolic stroke were generally appreciated on presentation. Conservative medical management was sufficient to protect from secondary neurological deficit regardless of index vertebral injury.

Machine learning and image analysis in vascular surgery.

Deep learning, a subset of machine learning within artificial intelligence, has been successful in medical image analysis in vascular surgery. Unlike traditional computer-based segmentation methods that manually extract features from input images, deep learning methods learn image features and classify data without making prior assumptions. Convolutional neural networks, the main type of deep learning for computer vision processing, are neural networks with multilevel architecture and weighted connections between nodes that can "auto-learn" through repeated exposure to training data without manual input or supervision. These networks have numerous applications in vascular surgery imaging analysis, particularly in disease classification, object identification, semantic segmentation, and instance segmentation. The purpose of this review article was to review the relevant concepts of machine learning image analysis and its application to the field of vascular surgery.

Machine learning analysis of confounding variables of a convolutional neural network specific for abdominal aortic aneurysms.

Objective: To identify confounding variables influencing the accuracy of a convolutional neural network (CNN) specific for infrarenal abdominal aortic aneurysms (AAAs) on computed tomography angiograms (CTAs). Methods: A Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, retrospective study analyzed abdominopelvic CTA scans from 200 patients with infrarenal AAAs and 200 propensity-matched control patients. An AAA-specific trained CNN was developed by the application of transfer learning to the VGG-16 base model using model training, validation, and testing techniques. Model accuracy and area under the curve were analyzed based on data sets (selected, balanced, or unbalanced), aneurysm size, extra-abdominal extension, dissections, and mural thrombus. Misjudgments were analyzed by review of heatmaps, via gradient weighted class activation, overlaid on CTA images. Results: The trained custom CNN model reported high test group accuracies of 94.1%, 99.1%, and 99.6% and area under the curve of 0.9900, 0.9998, and 0.9993 in selected (n = 120), balanced (n = 3704), and unbalanced image sets (n = 31,899), respectively. Despite an eightfold difference between balanced and unbalanced image sets, the CNN model demonstrated high test group sensitivities (98.7% vs 98.9%) and specificities (99.7% vs 99.3%) in unbalanced and balanced image sets, respectively. For aneurysm size, the CNN model demonstrates decreasing misjudgments as aneurysm size increases: 47% (16/34) for aneurysms <3.3 cm, 32% (11/34) for aneurysms 3.3 to 5 cm, and 20% (7/34) for aneurysms >5 cm. Aneurysms containing measurable mural thrombus were over-represented within type II (false-negative) misjudgments compared with type I (false-positive) misjudgments (71% vs 15%, P < .05). Inclusion of extra-abdominal aneurysm extension (thoracic or iliac artery) or dissection flaps in these imaging sets did not decrease the model's overall accuracy, indicating that the model performance was excellent without the need to clean the data set of confounding or comorbid diagnoses. Conclusions: Analysis of an AAA-specific CNN model can accurately screen and identify infrarenal AAAs on CTA despite varying pathology and quantitative data sets. The highest anatomic misjudgments were with small aneurysms (<3.3 cm) or the presence of mural thrombus. Accuracy of the CNN model is maintained despite the inclusion of extra-abdominal pathology and imbalanced data sets.

Development of a convolutional neural network to detect abdominal aortic aneurysms.

Objective: We sought to train a foundational convolutional neural network (CNN) for screening computed tomography (CT) angiography (CTA) scans for the presence of infrarenal abdominal aortic aneurysms (AAAs) for future predictive modeling and other artificial intelligence applications. Methods: From January 2015 to January 2020, a HIPAA (Health Insurance and Accountability Act)-compliant, institutional review board-approved, retrospective clinical study analyzed contrast-enhanced abdominopelvic CTA scans from 200 patients with infrarenal AAAs and 200 propensity-matched control patients with non-aneurysmal infrarenal abdominal aortas. A CNN was trained to binary classification on the input. For model improvement and testing, transfer learning using the ImageNet database was applied to the VGG-16 base model. The image dataset was randomized to sets of 60%, 10%, and 30% for model training, validation, and testing, respectively. A stochastic gradient descent was used for optimization. The models were assessed by testing validation accuracy and the area under the receiver operating characteristic curve. Results: Preliminary data demonstrated a nonrandom pattern of accuracy and detectability. Iterations (≤10) of the model characteristics generated a final custom CNN model reporting an accuracy of 99.1% and area under the receiver operating characteristic curve of 0.99. Misjudgments were analyzed through review of the heat maps generated via gradient weighted class activation mapping overlaid on the original CT images. The greatest misjudgments were seen in small aneurysms (<3.3 cm) with mural thrombus. Conclusions: Preliminary data from a CNN model have shown that the model can accurately screen and identify CTA findings of infrarenal AAAs. This model serves as a proof-of-concept to proceed with potential future directions to include expansion to predictive modeling and other artificial intelligence-based applications.

Pediatric Renal Artery Stenosis: A 19-Year Experience in Management and Outcomes at a Tertiary Pediatric Hospital.

BACKGROUND: Renal artery stenosis (RAS) is an uncommon cause of pediatric hypertension. Guidelines for workup and management have not been established. The most widely reported etiology of the pediatric renovascular disease has been fibromuscular dysplasia; however, other etiologies including middle aortic syndrome (MAS) and vasculitides have been described. We reviewed cases of radiologically identified pediatric RAS and describe etiologies, management, and long-term clinical outcomes in our patients. METHODS: Reports for duplex ultrasound, computed tomography angiography, magnetic resonance imaging, and conventional angiography from an academic children's hospital between 2000 and 2019 were evaluated. Positive reports for RAS were confirmed by a vascular surgeon and a radiologist. Demographics, indications for evaluation, management, and long-term clinical outcomes were documented. Data are summarized as count (n), geometric mean, median, or standard deviation as appropriate. Univariate differences between treatment cohorts were analyzed using Chi-squared tests for categorical variables. Nonparametric paired Wilcoxon signed-rank test and Mann-Whitney U-test were used for the analysis of paired ordinal or continuous data. A statistical analysis was performed with SPSS software (SPSS Inc., Chicago, IL) with significance defined at a P < 0.05 level. RESULTS: Imaging for suspected RAS was performed on 984 children. Of the 38 patients with positive imaging for RAS, 60.5% were idiopathic, 31.5% (n = 12) had concomitant congenital/systemic comorbidity, and 21.0% (n = 8) had RAS and concomitant aortic pathology. Fibromuscular dysplasia only accounted for 13.2% (n = 5) of patients. Regarding management, 34.2% (n = 13) underwent invasive intervention, 23.7% (n = 9) underwent endovascular intervention alone, and 10.5% (n = 4) underwent endovascular plus surgical intervention. Conservative management was performed for 65.8% (n = 25) of patients at a long-term follow-up (33.8 months), 34.2% (n = 13) requiring only lifestyle changes, and 31.6% (n = 12) requiring only medical management. CONCLUSIONS: Pediatric RAS is a low-frequency disease and long-term outcomes have been under-reported. The incidence of associated aortic pathology in our intervention cohort appears higher than that was previously reported. A long-term follow-up demonstrated that up to 65.8% of patients could be managed successfully with conservative therapy.

Analysis of Traumatic Axillo-Subclavian Vessel Injuries: Endovascular Management is a Viable Option to Open Surgical Reconstruction.

BACKGROUND: In traumatic axillo-subclavian vessel injuries, endovascular repair has been increasingly described, despite ongoing questions regarding infection risk and long-term durability. We sought to compare the clinical and safety outcomes between endovascular and surgical treatment of traumatic axillo-subclavian vessel injuries. METHOD: A search query of the prospectively maintained PROOVIT registry for patients older than 18 years of age with a diagnosis of axillary or subclavian vessel injury between 2014-2019 was performed at a Level 1 Trauma Center. Patient demographics, severity of injury, Mangled Extremity Severity Score (MESS), Injury Severity Score (ISS), procedural interventions, complications, and patency outcomes were collected and analyzed. RESULTS: Twenty-three patients with traumatic axillo-subclavian vessel injuries were included. There were similar rates of penetrating and blunt injuries (48% vs. 52%, respectively). Eighteen patients (78%) underwent intervention: 11 underwent endovascular stenting or diagnostic angiography; 7 underwent open surgical repair. There was similar severity of arterial injuries between the endovascular and open surgical groups: transection (30% vs. 40%, respectively), occlusion (30% vs. 40%, respectively). The open surgical group had worse initial clinical comorbidities: higher ISS scores (17.0 vs 13.5, p = 0.034), higher median MESS scores (6 vs. 3.5, P = 0.001). The technical success for the endovascular group was 100%. The endovascular group had a lower estimated procedural blood loss (27.5 mL vs. 624 mL, P = 0.03). The endovascular arterial group trended toward a shorter length of hospital stay (5.6 days vs. 27.6 days, P = 0.09) and slightly reduced procedural time (191.0 min vs. 223.5 min, P = 0.165). Regarding imaging follow up (average of 60 days post-discharge), 7 patients (54%) underwent surveillance imaging (5 with duplex ultrasound, 2 with computed tomography angiography CTA) that demonstrated 100% patency. Regardless of ISS or MESS scores, at long term clinical follow up (average of 214 days), there were no limb losses, graft infections or vascular complications in either the endovascular or open surgical group. CONCLUSIONS: Endovascular treatment is a viable option for axillo-subclavian vessel injuries. Preliminary results demonstrate that endovascular treatment, when compared to open surgical repair, can have similar rates of technical success and long-term outcomes in patency, infection and vascular complications.

Health Care System-Wide Analysis Identifies High Radiation Use Factors and Behaviors in Surgery.

OBJECTIVE: Usage of radiation among various surgical specialists has not been comprehensively evaluated. A systems-based analysis evaluating intraoperative radiation can help identify high use factors and dose reduction behaviors leading to quality improvement initiatives. METHODS: A retrospective review of all operative fluoroscopic-guided procedures from 2010 to 2017 from 4 hospitals in a tertiary academic health care system was performed. RESULTS: One thousand two hundred fifty-two cases were analyzed, and notable trends in metrics including type of equipment, procedures, surgical field, surgical specialty, and dose reduction techniques were demonstrated. Higher radiation exposures were correlated with fixed vs. mobile C-arm usage (1229 mGy vs. 331 mGy, P = .001), abdominal/pelvic procedures (429.2 mGy vs. 274.0 mGy, P = .002), and embolization (2450.6 mGy vs. 328.2 mGy, P = .019). Vascular surgery averaged 40 times higher radiation exposure per patient than other specialties (613.3 mGy vs. 15.6 mGy, P = .001). Notably, vascular surgeons utilized dose reduction techniques less frequently than urology (21.5% vs. 70%, P = .001) but more than neurosurgery and orthopedics (21.5% vs. 1.3% and 0%, P = .001, respectively). CONCLUSIONS: A system-wide health care analysis identified vascular surgery procedures, use of a fixed C-arm, abdominal/pelvic procedures, and embolization cases as having the highest radiation exposure. These data can serve as baseline information for future quality improvement initiatives regarding fluoroscopy usage by surgeons.

Quantitative CT Predictors of Portal Venous Intervention in Uncontrolled Variceal Bleeding.

OBJECTIVE. The purpose of this study was to quantify abdominal CT predictors of endoscopically refractory, uncontrolled variceal hemorrhage requiring portal venous intervention. MATERIALS AND METHODS. From 2009 to 2018, 64 patients with endoscopically refractory variceal hemorrhage requiring portal venous intervention (variceal hemorrhage group) and 67 patients without hemorrhage but with symptomatic, pressure gradient-proven portal hypertension (control group) underwent CT. CT scans were retrospectively reviewed for the following: varix size, variceal intraluminal protrusion, liver and spleen volumes, and portal vein diameter. RESULTS. Gastric variceal protrusion was found to be a strong CT parameter associated with refractory hemorrhage (mean depth, 0.75 mm in variceal hemorrhage group vs -2.91 mm in control group; p = 0.001). Gastric varix size was also associated with variceal hemorrhage (mean diameter, 8.03 vs 6.51 mm; p = 0.001). However, this trend was not observed in the sizes of the esophageal varices (mean diameter, 6.28 vs 6.43 mm; p = 0.370). Larger spleen volume (mean, 1312 vs 1152 cm3; p = 0.029) and liver volume (mean, 1514 vs 1143 cm3; p = 0.004) were also found to be predictors of variceal hemorrhage. Significant CT threshold findings included gastric variceal protrusion depth more than 0 mm (odds ratio [OR], 6.44), gastric varix size more than 6 mm (OR, 3.89), spleen volume more than 1000 cm3 (OR, 2.63), and liver volume more than 1000 cm3 (OR, 2.82). CONCLUSION. Quantitative imaging parameters on abdominal CT, such as intraluminal protrusion of gastric varices, gastric varix size, and larger spleen and liver volumes, were predictive of portal venous intervention, whereas esophageal varix size was not.

Fatal Lung Toxicity After Intralesional Bleomycin Sclerotherapy of a Vascular Malformation.

Although there has been increased utilization of bleomycin in the treatment of low-flow vascular malformations in children, previous studies report minor adverse effects limited to skin changes/necrosis and flu-like symptoms (Horbach et al. in J Plast Reconstr Aesthet Surg 69(3):295-304, 2016). However, there have been rare reported cases of pulmonary injury observed in children after bleomycin intralesional administration. We report a case of fatal lung toxicity in a 15-month-old girl after injecting 7 units of bleomycin into a left cheek macrocystic lymphatic malformation. 1 week after therapy, she developed respiratory distress with imaging findings of pneumothorax and diffuse alveolar damage. Despite extensive management and resuscitative efforts of presumed pneumonitis, further decline resulted in death via respiratory failure. Early detection of pulmonary toxicity would allow prompt therapy and could avoid significant pulmonary damage.

Native Microchannel Recanalization with Orbital Atherectomy as a Viable Alternative to Failed Standard Recanalization of TASC II D Aortoiliac Occlusive Disease.

BACKGROUND: Endovascular treatment of Trans-Atlantic Inter-Society Consensus (TASC) II D aortoiliac lesions is now an accepted form of revascularization. We sought to demonstrate that native microchannel recanalization and orbital atherectomy is a successful recanalization method of TASC II D aortoiliac lesions refractory to standard recanalization techniques. METHODS: Four consecutive patients from 2016 to 2018 with symptomatic TASC II D aortoiliac occlusive disease prohibitive for open bypass and failed traditional prodding guidewire or device recanalization technique were identified and underwent advanced native microchannel selection and subsequent orbital atherectomy (Cardiovascular Systems, Inc, St Paul, MN). Native microchannels of the calcified lesions were probed and traversed with a 0.014″ wire. The atherectomy crown was tracked over the wire, and orbital atherectomy was initiated with a 1.25 mm crown starting at the lowest revolution and continued until the microchannel is sufficiently large to track a 1.2 mm-balloon for angioplasty. Serial microchannel angioplasty with exchange for stiffer and/or larger profile wires and balloons was achieved until a covered stent could be safely deployed across the target lesion. The kissing stent technique was then used to recreate the aortic bifurcation. A ViperSlide lubricant solution was used in all cases per indication for use. Patients were all heparinized to maintain an activated clotting time of 250. Lesion characteristics, survival, limb salvage, patency, and change in clinical symptoms were also analyzed. RESULTS: All 4 patients underwent successful native microchannel recanalization and orbital atherectomy of the common iliac artery (CIA). There were no intraoperative ruptures, embolizations, or dissections. All 4 patients presented with unilateral CIA occlusion with contralateral CIA stenosis. The average occlusion lesion length of the CIA was 6.0 cm. The average contralateral stenosis length was 2.3 cm. The kissing stent technique was used in all patients for reconstruction of the aortic bifurcation. At 30 days, all patients had improvement in pain and primary patency of 100%. Long-term follow-up at 21.6 months noted continued improvement in symptoms and primary patency of 75%. The fourth patient died at 4 months from lung cancer with occluded iliac stents by imaging at that time. CONCLUSIONS: Native microchannel recanalization with subsequent orbital atherectomy is an option in high-risk patients with TASC II D aortoiliac disease who have failed traditional recanalization techniques. Further work in proper patient selection and safe utilization of atherectomy devices in the CIA is needed.

Analysis of Subjective and Objective Screening Techniques as Predictors of Safety for Radial Artery Intervention.

BACKGROUND: There is no currently accepted standard in safety evaluation for radial artery intervention. We sought to compare the accuracy of various subjective and objective screening techniques in predicting safety for radial artery intervention. METHODS: Fifty-four patients in a prospective cohort study at a single institution underwent subjective Allen's test, objective Barbeau test, and several objective hand ultrasound techniques to assess safety for radial artery intervention. These results were then compared to the gold standard of conventional hand angiography to document complete palmar arch. Statistical analysis including sensitivity, specificity, positive predictive values, negative predictive values, and accuracy were calculated. RESULTS: Compared to hand angiography, the subjective Allen's test and the objective Princeps Pollicis Artery ultrasound demonstrated the comparable levels of sensitivity (100% vs. 96.7%, respectively), specificity (100% vs. 100%, respectively), and accuracy (97.2% vs. 97.1%, respectively). The objective Barbeau test demonstrated similar results (sensitivity of 100%, accuracy of 98.2%) with the exception of a lower specificity (50%). CONCLUSIONS: There is no currently accepted standard in safety evaluation for radial artery intervention. However, preliminary data suggest that certain subjective and objective techniques such as Allen's testing, Princeps Pollicis artery ultrasound, and Barbeau testing are comparable options in predicting palmar arch patency.

Trans-Atlantic Inter-Society Consensus Class D Aortoiliac Lesions: A Comparison of Endovascular and Open Surgical Outcomes.

OBJECTIVE. The purpose of this study is to compare the clinical and safety outcomes between two groups of patients with Trans-Atlantic Inter-Society Consensus class D (TASC II D) aortoiliac occlusive disease (AIOD): those with higher-risk comorbidity who underwent endovascular reconstruction and those with lower-risk comorbidity who underwent surgical bypass. MATERIALS AND METHODS. Thirty-two consecutive patients with symptomatic TASC II D AOID who underwent surgical bypass or endovascular reconstruction from 2012 to 2017 were retrospectively reviewed. Lesion characteristics, technical approach, survival, limb salvage, patency, and change in clinical symptoms were analyzed. RESULTS. Nineteen patients with higher comorbidity underwent endovascular reconstruction, whereas 13 patients with lower comorbidity underwent surgical bypass. Patients undergoing endovascular reconstruction had an older median age (67.0 vs 62.0 years; p = 0.007), higher rates of hypertension (94.7% vs 61.5%; p = 0.018) and coronary artery disease (26.3% vs 0%; p = 0.044), and advanced renal impairment (mean [± SD] chronic kidney disease stage, 1.4 ± 1.5 vs 0.7 ± 1.3; p = 0.005). There were no significant differences in Rutherford classification between the groups. During long-term follow-up of 2.76 years, endovascular reconstruction and surgical bypass showed equivalent rates of survival (89.5% vs 84.6%; p = 0.683), limb salvage (100.0% vs 92.3%; p = 0.219), and primary or primary-assisted patency (85% vs 85%; p = 0.98). Groups showed similar clinical improvements in walking distance, rest pain, and tissue loss at 30 days (95% vs 85%; p = 0.158) and at long-term follow-up (74% vs 62%; p = 0.599). CONCLUSION. For properly selected patients, the clinical outcomes of endovascular reconstruction versus surgical bypass for TASC II D AOID may be equivalent at 2.5 years after the procedure. The decreased operative risk associated with endovascular reconstruction suggests that it is the technique of choice for high-risk patients.

Early Surgical Referral for Penetrating Aortic Ulcer Leads to Improved Outcome and Overall Survival.

BACKGROUND: The natural history of penetrating aortic ulcer (PAU) has been variably described and clear guidelines are lacking. We reviewed our experience with PAUs in a tertiary referral center. METHODS: Imaging reports from January 2010 to December 2017 were retrospectively searched for the diagnosis of "penetrating aortic ulcer." Diagnosis was confirmed by review of imaging studies. Patient demographics, presenting symptoms, and anatomic characteristics were collected and analyzed for associations with need for surgical intervention, aortic complication, and overall survival. RESULTS: One hundred six patients with PAU were identified. Locations included 57 (53.8%) aortic arch, 24 (22.6%) descending thoracic, and 25 (23.5%) abdominal aorta. Dissection was present in 12 (11.4%) and acute rupture in 4 (3.8%) cases. At presentation, 57 (53.8%) patients were symptomatic. Forty-six (43.8%) patients were evaluated by cardiothoracic or vascular surgeons. Thirteen (12.3%) underwent surgical or endovascular repair and 10 (10.4%) had a change in medical management. Long-term follow-up (LTFU) was available in 30 patients for a mean of 36.5 ± 29.2 months. Twenty-one (70%, 21/30) demonstrated disease stability or resolution and 9 (30%, 9/30) worsened with 3 undergoing surgery. No PAU ruptured during follow-up. Patient demographics, presenting symptoms, and PAU morphology did not predict disease progression. Referral to a cardiovascular surgeon at initial presentation was associated with a 40% decreased likelihood of disease progression (P = 0.046) and a 60% survival advantage at LTFU (P = 0.037). CONCLUSIONS: PAU disease progression occurs in 30% of patients at LTFU of 36.5 ± 29.2 months. All patients identified with PAU on diagnostic imaging should be referred for a surgical evaluation and follow-up, as referral to cardiovascular surgeon is associated with improved disease course.

Analysis of intraoperative radiation use in vascular surgery: Catalyst for quality improvement in patient and personnel safety.

OBJECTIVES: There is paucity in the literature reporting radiation usage analysis in vascular surgery. In the era of endovascular surgeries, analyzing the surgeons' use of radiation in vascular procedures can help establish quality improvement initiatives. METHODS: A retrospective review was undertaken of intraoperative fluoroscopic-guided vascular surgery procedures at a single institution from 2010 to 2017. Mobile C-arms were utilized to gather the six radiation usage metrics and cases were categorized into 6 anatomic surgical fields and 10 surgical procedure types. RESULTS: Three hundred and eighteen vascular surgery cases were analyzed and notable trends in all radiation usage metrics were identified both across the surgical field location and type of surgical procedure. The highest cumulative dose was identified in embolization cases with a mean of 932.5 mGy. The highest fluoroscopic time was seen in atherectomies with a mean of 2629.6 s. In terms of surgical field, the highest cumulative does and fluoroscopic time was identified in abdomen/pelvis procedures with a mean of 352.1 mGy and 1186.8 s, respectively. Analysis of dose reduction techniques also demonstrated notable trends. CONCLUSIONS: There were notable trends in the analyzed radiation usage variables both across the surgical field location and type of surgical procedure. Specifically, cases that involve the abdomen/pelvis, embolization and atherectomy have the highest radiation use. These types of cases can be targeted for future improved dose reduction techniques or staged procedures. This data can serve as baseline information for future quality improvement initiatives for patient and personnel radiation exposure safety.