Vascular complications secondary to resuscitative endovascular balloon occlusion of the aorta placement at a Level 1 Trauma Center.

OBJECTIVE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is designed to manage severe hemorrhagic shock. Popularized in medical care during military conflicts, the concept has emerged as a lifesaving technique that is utilized around the United States. Literature on risks of REBOA placement, especially vascular injuries, are not well-reported. Our goal was to assess the incidence of vascular injury from REBOA placement and the risk factors associated with injury and death among these patients at our institution. METHODS: We performed a retrospective cohort study of all patients who underwent REBOA placement between September 2017 and June 2022 at our Level 1 Trauma Center. The primary outcome variable was the presence of an injury related to REBOA insertion or use. Secondary outcomes studied were limb loss, the need for dialysis, and mortality. Data were analyzed using descriptive statistics, χ2, and t-tests as appropriate for the variable type. RESULTS: We identified 99 patients who underwent REBOA placement during the study period. The mean age of patients was 43.1 ± 17.2 years, and 67.7% (67/99) were males. The majority of injuries were from blunt trauma (79.8%; 79/99). Twelve of the patients (12.1%; 12/99) had a vascular injury related to REBOA placement. All but one required intervention. The complications included local vessel injury (58.3%; 7/12), distal embolization (16.7%; 2/12), excessive bleeding requiring vascular consult (8.3%; 1/12), pseudoaneurysm requiring intervention (8.3%; 1/12), and one incident of inability to remove the REBOA device (8.3%; 1/12). The repairs were performed by vascular surgery (75%; 9/12), interventional radiology (16.7%; 2/12), and trauma surgery (8.3%; 1/12). There was no association of age, gender, race, and blunt vs penetrating injury to REBOA-related complications. Mortality in this patient population was high (40.4%), but there was no association with REBOA-related complications. Ipsilateral limb loss occurred in two patients with REBOA-related injuries, but both were due to their injuries and not to REBOA-related ischemia. CONCLUSIONS: Although vascular complications are not unusual in REBOA placement, there does not appear to be an association with limb loss, dialysis, or mortality if they are addressed promptly. Close coordination between vascular surgeons and trauma surgeons is essential in patients undergoing REBOA placement.

Machine learning-based prediction of abdominal aortic aneurysms for individualized patient care.

OBJECTIVE: The United States Preventative Services Task Force guidelines for screening for abdominal aortic aneurysms (AAA) are broad and exclude many at risk groups. We analyzed a large AAA screening database to examine the utility of a novel machine learning (ML) model for predicting individual risk of AAA. METHODS: We created a ML model to predict the presence of AAAs (>3 cm) from the database of a national nonprofit screening organization (AAAneurysm Outreach). Participants self-reported demographics and comorbidities. The model is a two-layered feed-forward shallow network. The ML model then generated AAA probability based on patient characteristics. We evaluated graphs to determine significant factors, and then compared those graphs with a traditional logistic regression model. RESULTS: We analyzed a cohort of 10,033 patients with an AAA prevalence of 2.74%. Consistent with logistic regression analysis, the ML model identified the following predictors of AAA: Caucasian race, male gender, advancing age, and recent or past smoker with recent smoker having a more profound affect (P < .05). Interestingly, the ML model showed body mass index (BMI) was associated with likelihood of AAAs, especially for younger females. The ML model also identified a higher than predicted risk of AAA in several groups, including female nonsmokers with cardiac disease, female diabetics, those with a family history of AAA, and those with hypertension or hyperlipidemia at older ages. An elevated BMI conveyed a higher than expected risk in male smokers and all females. The ML model also identified a complex relationship of both diabetes mellitus and hyperlipidemia with gender. Family history of AAA was a more important risk factor in the ML model for both men and women too. CONCLUSIONS: We successfully developed an ML model based on an AAA screening database that unveils a complex relationship between AAA prevalence and many risk factors, including BMI. The model also highlights the need to expand AAA screening efforts in women. Using ML models in the clinical setting has the potential to deliver precise, individualized screening recommendations.

The role of vascular surgeons in the management of pediatric bone tumors.

OBJECTIVES: The objective of this study was to review the outcomes of a multidisciplinary approach to the surgical management of pediatric bone tumors with blood vessel involvement over a 14- year period. METHODS: A retrospective review was conducted of all pediatric bone tumor resections performed with the assistance of vascular surgery at our institution between January 2006 and January 2021. Inclusion criteria for the study included the presence of a vascular surgeon at the operative resection and radiographic evidence of major blood vessel involvement. RESULTS: From 2006 to 2021, 117 patients underwent a bone tumor resection by a single orthopedic surgeon/vascular surgeon team. Sixty were malignant tumors, and 57 were benign. Of the 117 procedures, 5.1% (6/117) required reconstruction of an artery; five in malignant cases and one in benign. No venous reconstructions were undertaken in this study. Ligation of a major artery without reconstruction was performed in 8.8% (5/57) of malignant and 1.7% (1/60) of benign resections. Despite this vessel-sparing approach, microscopic margins were clear in all cases. Local recurrence occurred in a single patient in the malignant group at 61 months. CONCLUSIONS: The ideal management of pediatric bone tumors with major blood vessel involvement remains poorly defined. Our results demonstrate that even in the setting of radiographic evidence of vessel involvement, a multidisciplinary team of vascular and orthopedic surgeons can employ a vessel-sparing approach with minimal blood loss, excellent limb salvage, and minimal local recurrence.

A Novel Clinically Based Classification System for the Profunda Femoris Artery and the Circumflex Femoral Arteries.

BACKGROUND: The profunda femoris artery (PFA) supplies important collateral branches to both the ipsilateral internal iliac artery and the distal superficial femoral artery (SFA). The size and patency of these collateral pathways can determine the risk of pelvic malperfusion, spinal cord ischemia, and lower extremity limb loss following vascular interventions. Despite its importance, the anatomy of the PFA is rarely characterized in clinical studies involving the pelvic or lower extremity circulation. This discussion may be limited by the lack of a comprehensive classification system. Our objective was to describe the most common PFA anatomic variants and present a classification system based on its branching patterns. METHODS: We dissected 155 fixed and nonfixed femoral artery systems from 88 cadavers. Seventy-seven female and 78 male femoral exposures were performed. Vessel diameters, branch configurations, and relative distances between the inguinal ligament, PFA, lateral circumflex femoral artery (LCFA), and medial circumflex femoral artery (MCFA) were recorded. RESULTS: The mean diameters of the common femoral artery, SFA, and PFA were 10.3 mm, 8.0 mm, and 6.9 mm in males and 8.9 mm, 6.9 mm, and 6.1 mm in females, respectively (P < 0.05). The mean distances from the inguinal ligament for PFA, MCFA, and LCFA were 41 mm, 41.7 mm, and 52.5 mm, respectively. No significant differences were noted relative to laterality or fixation. We developed a clinically applicable classification system based on the orientation of the PFA, LCFA, and MCFA. Six PFA, 5 LCFA, and 5 MCFA variations were identified and ranked by frequency. The 5 most common combinations accounted for 56.1% of our cadaver series. CONCLUSIONS: The anatomic orientation of the PFA and its branches is highly variable. We propose a novel classification system of this rich collateral system to facilitate consistent communication in academic and clinical vascular surgery.

A proposed model for a comprehensive virtual subinternship in vascular surgery.

OBJECTIVE: In the present study, we sought to understand the challenges, advantages, and applications of a vascular surgery virtual subinternship (VSI) curriculum. METHODS: Our institution hosted 25 students for two 4-week VSI rotations, one in July 2020 and one in August 2020. The students participated in a curriculum centered around the use of Zoom and telephone interactions with residents and faculty. The curriculum included selected readings, surgical videos, group didactics, and one-on-one mentorship. Anonymous pre- and postrotation self-assessments were used to ascertain the students' achievement of the learning objectives and the utility of the educational tools implemented during the rotation. The faculty and resident mentors were also surveyed to assess their experience. RESULTS: With the exception of knot-tying techniques (P = .67), the students reported significant improvement in their understanding of vascular surgery concepts after the virtual elective (P < .05). The highest ranked components of the course were interpersonal, including interaction with faculty, mentorship, and learning the program culture. The lowest ranked components of the course were simulation training and research opportunities. The rating of the utility of aspects of the course were consistent with the ranking of the components, with faculty interaction receiving the highest average rating. The ideal amount of time for daily virtual interaction reported by the students ranged from 3 to 6 hours (median, 4 hours). Overall, most of the mentors were satisfied with the virtual course. However, they reported limited ability to assess the students' personality and fit for the program. The time spent per week by the mentors on the virtual vascular surgery rotation ranged from 2 to 7 hours (median, 4 hours). Of the 17 mentors completing the surveys, 14 reported that having a virtual student was a significant addition to their existing workload. CONCLUSIONS: Overall, our student and mentor feedback was positive. Several challenges inherent to the virtual environment still require refinement. However, the goals of a VSI are distinct and should be explored by training programs. With changes to healthcare in the United States on the horizon and the constraints resulting from the severe acute respiratory syndrome coronavirus 2 pandemic, implementing a virtual away rotation could be an acceptable platform in our adaptations of our recruitment strategies.

Evaluating the prevalence of abdominal aortic aneurysms in the United States through a national screening database.

OBJECTIVE: The U.S. Preventative Services Task Force guidelines for abdominal aortic aneurysm (AAA) screening are based mainly on studies of older Caucasian males from non-U.S. POPULATIONS: This study was designed to analyze the findings of a large, all-inclusive AAA screening program in the United States. METHODS: Screening events were held nationally by a U.S. nonprofit organization between 2001 and 2017. AAA screening was offered regardless of risk profile. Participants filled out a demographics form with known comorbidities. Significant risk factors were determined using logistic regression with backward stepwise variable selection. Odds ratios (OR) are reported with 95% confidence intervals (CIs). RESULTS: A total of 9457 screened participants (47% male) were analyzed. The mean age was 67 ± 9 years with 40.8% between 65 and 75 years old. Most participants were Caucasian (83.4%), followed by African American (13.1%). Screened risk factors included hypertension (58.1%), hyperlipidemia (54.9%), smoking (52.0%), cardiac disease (29.2%), diabetes mellitus (18.4%), a family history of AAA (22.4%) or brain aneurysms (8.6%), and body mass index (26.9 ± 5.28). Overall, 267 participants (2.82%) were found to have an AAA (>3 cm). Those ages 65 to 75 had a prevalence of 2.98%. In a fully adjusted, multivariate logistic regression, there was an increased risk of AAA in males (OR, 3.24; 95% CI, 2.39-4.40), current smokers (OR, 3.28; 95% CI, 2.36-4.54), previous smokers (OR, 1.86; 95% CI, 1.41-2.47), cardiac disease (OR, 1.30; 95% CI, 1.01-1.68), family history of AAA (OR, 1.60; 95% CI, 1.20-2.14), and advancing age (P < .0001). Female ever smokers 65 to 75 years old had a prevalence of 1.7%. Male smokers 45 to 54 and 55 to 64 years old had a prevalence of 3.37% and 4.43%, respectively. There was an increased risk of AAA in females with morbid obesity (OR, 5.54; 95% CI, 1.34-22.83 in never smokers and OR, 5.61; 95% CI, 1.04-30.15 in smokers), female smokers with hypertension (OR, 3.22; 95% CI, 1.21-8.58), males with cardiac disease (OR, 2.06; 95% CI, 1.08-3.90 in never smokers and OR, 1.48; 95% CI, 1.05-2.09), male smokers with a family history of AAA (OR, 1.69; 95% CI, 1.61-2.46), and current smokers (OR, 6.33; 95% CI, 2.62-15.24 for females and OR, 2.50; 95% CI, 1.70-3.65 for males). CONCLUSIONS: This study shows that there remain high-risk groups outside the current guidelines that would likely benefit from AAA screening. Risk factors for AAA include male gender, smoking, cardiac disease, family history of AAA, and advancing age. The most significant risk factor is current smoking status.

Six-year history of intermittent symptomatic bilateral vertebral artery stenosis: Imaging and therapeutic intervention.

A 66-year-old man was evaluated for a 6-year history of disabling symptoms of typical intermittent vertebrobasilar (VB) insufficiency. Duplex scanning was "normal," but computed tomographic angiography (CTA) revealed significant bilateral proximal vertebral artery (VA) disease. Angiography with stent placement with the proximal right VA resulted in resolution of symptoms. Symptoms of VB insufficiency may occur from bilateral VA disease, most often involving both proximal segments. Duplex ultrasound has high specificity but relatively low sensitivity for finding hemodynamically significant VA disease. Further imaging with CTA or magnetic resonance angiography (MRA) will help in identification of disease. As with this patient, invasive angiography with percutaneous stenting of the most significantly stenosed VA often results in resolution of symptoms of VB insufficiency.

Aortic Transection after Blunt Abdominal Trauma in a Child.

Abdominal aortic injury secondary to blunt abdominal aortic trauma (BAAI) is rare in children but frequently occurs in association with other injuries, including bowel injury and vertebral fracture. We present a case of a 14-year-old boy who sustained a partial transection of the infrarenal aorta with a lumbar chance fracture and small bowel injury after a motor vehicle accident. Repair was performed with bowel resection followed by Dacron graft interposition. We reviewed the literature on BAAI in children with a focus on the method of repair of these injuries.

Health literacy and abdominal aortic aneurysms.

OBJECTIVE: Little is known about the public's knowledge of abdominal aortic aneurysms (AAA). Although preventive screening is available, millions of Americans remain unaware of their risk. Improved health literacy has been associated with increased screening and improvement in health outcomes. This study assessed the level of AAA literacy among respondents who participated in a free AAA screening event. METHODS: Thirteen key words used by vascular surgeons to describe the risk, diagnosis, and treatment options for AAA were extracted from the screening tool used by the nation's largest provider of free AAA diagnostic services, AAAneurysm Outreach. The National Institutes of Health recommends readability of patient education materials to be at the sixth-grade level, but a readability analysis of these words placed them at a grade level of 14.6. A self-administrated questionnaire was developed that allowed respondents to compare each of the extracted words with a definitionally correct or incorrect word that reflected a sixth-grade readability score. These scores were then compared with the available demographics. RESULTS: There were 570 completed questionnaires. Of the participants, 57.6% were female, 61.4% were 60 and above, and 32.6% were veterans. The average number of correct answers was 9.31 out of 13 (72% correct). Only 4.7% answered all questions correctly, with 29.1% missing five or more answers. The most frequently missed words were asymptomatic, screening, and cholesterol (56.5%, 44%, and 41.4% incorrect, respectively). The most frequently known terms were abdominal, diagnosis, and genetic (96%, 95.3%, and 91.9% correct, respectively). The remaining words fell between these extremes. Those aged 60 and above scored significantly lower than younger respondents (P < .0001). A post hoc power analysis indicated that the power to detect the obtained effects of age at the .05 level was greater than 0.95. Gender and veteran status did not produce any significant differences. CONCLUSIONS: These data suggest an important communication gap between the words used by clinicians to describe the risks, diagnostic results, and treatment options of AAA and the targeted at-risk population, especially those 60 years and older.

Statistical and machine learning methodology for abdominal aortic aneurysm prediction from ultrasound screenings.

A method of analysis of a database of patients (n = 10 329) screened for an abdominal aortic aneurysm (AAA) is presented. Self-reported height, weight, age, gender, ethnicity, and parameters "Heart Problems," "Hypertension," "High Cholesterol," "Diabetes Mellitus," "Smoker Past 2 Years," "Ever Smoked?," "Family History AAA," and "Family History Brain Aneurysm" were provided. Incidence of a AAA (defined as 3 cm diameter) was calculated as a function of age and body mass index (BMI) of greater than or less than a BMI 25 for various patient groups. Age was grouped into one of three categories in 15-year intervals (35-50 years, 50-65 years, and 65 to 80 years). Most patients were Caucasian (n = 8575) and the largest group of patients with a AAA was the Caucasian male (198 of 279 total detected AAAs). A machine learning algorithm was written, with learning inputs from the acquired patient database. Of all groups, Caucasian males were found to have the highest incidence of AAA, with males in general higher than females. Smoking within the past two years was highly associated with AAA incidence, and a past history of smoking to a lesser extent. The incidence of AAA increased with age. When dividing groups into two cohorts by a BMI of 25, generally middle-aged patients with a BMI > 25 had a higher incidence of a AAA. However, in general, the older age group with a BMI < 25 had a higher incidence of AAA. The addition of machine learning allows one to note the effect of an input keeping other input parameters constant. This helps identify a parameter that may be an independent predictor of a particular outcome. When using BMI as the single changing input, an increasing BMI was associated with an increased probability of a AAA, most significantly in middle-aged patients, and then narrowing to similar probabilities in older age. This AAA screening program is ongoing. As data continues to be collected with particularly those patient groups presently underrepresented, questions as to an association of AAA with BMI as a function of age, and also an improvement in machine learning algorithm accuracy for various patient populations will continue.

The pathway to a national vascular skills examination and the role of simulation-based training in an increasingly complex specialty.

The evolving demands of surgical training have led to the successful implementation of skills examinations in the areas of laparoscopic and endoscopic surgery. Currently, there is no similar formal skills assessment in vascular surgery, despite endovascular intervention replacing open surgery in treatment of many vascular conditions. The adoption of less invasive techniques to treat aneurysm and occlusive disease has resulted in new training paradigms and technical challenges for trainees. The duty hour restriction for trainees and declining numbers of complex open vascular interventions have added to the challenges of vascular surgery training. Simulation is a promising avenue for both skills training and assessment. The ability to evaluate the fundamental skills of trainees would be an important step to ensure a degree of uniformity in trainees' technical abilities. The role of simulation-based training in acquiring, testing, and refining these skills is still in its infancy in the vascular surgery training paradigm. This article aims to impart a deeper understanding of the conditions for developing and implementing the fundamentals of vascular and endovascular surgery, and to provide guidance regarding the role of simulation-based training in a rapidly evolving specialty. There are various forms of simulation available, including benchtop models, high-fidelity simulators, and virtual-reality simulators, and each requires a different method of proficiency assessment. Both open surgery and endovascular skills can be assessed and the application of successful implementation in academic vascular surgery training program is presented.

Carotid artery fibromuscular dysplasia: Ultrasound and CT imaging.

An asymptomatic 54-year-old Caucasian female was found to have a right carotid bruit located high in the cervical region. Carotid duplex ultrasound revealed carotid intimal disease with increased Doppler flow in the mid-distal right internal carotid artery (RICA) with color Doppler turbulence in the distal RICA. Computed tomography angiography (CTA) revealed a typical "string-of-beads" sign in both distal internal carotid artery (ICAs), diagnostic of fibromuscular dysplasia (FMD). While often not diagnostic, carotid duplex ultrasound may yield clues as to diagnosis of FMD with elevated Doppler velocity in the distal carotid, turbulent distal carotid flow, and possibly a "string-of-beads" sign. An "S-curve" distal ICA is associated with FMD and may warrant further evaluation. Magnetic resonance angiography and CTA appear to be better for diagnosis of carotid FMD. The typical "string-of-beads" may be readily identified. While invasive angiography is considered the "gold standard" for diagnosis of carotid FMD, it is infrequently required. Generally, invasive angiography is performed in symptomatic patients in planning for interventional therapy.

Open resection and laryngotracheal reconstruction in a case of subglottic hemangioma in PHACE syndrome.

We describe a 1 month old infant with PHACE syndrome who underwent successful management of subglottic hemangioma by open resection and laryngotracheal reconstruction using a thyroid ala graft. Propranolol is typically the treatment of choice for subglottic hemangiomas however, recent reports have suggested adverse complications with the use of propranolol in children with PHACE syndrome. The child had cerebral and cervical vascular anomalies associated with her PHACE syndrome making her at an increased risk of stroke with the use of propranolol.

Aortic arch and descending thoracic aortic aneurysms: experience with stent grafting for second-stage "elephant trunk" repair.

Reconstruction of aortic arch and descending thoracic aortic aneurysms (TAAs) is technically challenging and associated with significant morbidity and mortality. We report our experience with extensive TAAs using a two-stage "elephant trunk" repair, with the second stage completed using an endovascular stent graft (ESG). Over 6 years, 111 patients underwent ESG treatment of TAAs at Mount Sinai Medical Center. Twelve of these patients were referred for ESG placement for the second stage of elephant trunk reconstruction because comorbidities placed them at high risk of open surgical repair. Our database was analyzed for technical and clinical success and perioperative complications. The mean follow-up was 11.8 months (range 1-64 months). Twelve patients (five women and seven men) with a mean age of 69 +/- 10 years underwent repair of their distal aortic arch and descending TAAs. These aneurysms included nine atherosclerotic aneurysms, one pseudoaneurysm, and two penetrating atherosclerotic ulcers. Three patients were symptomatic. Stent graft repair was technically successful in 91.7% or 11 of 12 patients. Excessive aortic arch tortuosity resulted in failure to deploy a stent graft in one patient. An antegrade approach through the open elephant trunk was used in two patients with severe iliac occlusive disease. Endoleaks (type 2) were identified in two patients with no aneurysm expansion; however, a 14 mm expansion over 1 year occurred in a patient with no identifiable endoleak. One early mortality occurred in a patient with a ruptured 6 cm infrarenal AAA after successful exclusion of the 8 cm TAA. Second-stage elephant trunk reconstruction of an extensive TAA using an ESG is effective in the short term. Its long-term durability remains to be determined.

First experience in human beings with a permanently implantable intrasac pressure transducer for monitoring endovascular repair of abdominal aortic aneurysms.

OBJECTIVES: Endovascular stent graft repair of abdominal aortic aneurysms (AAAs) prevents rupture by excluding the aneurysm sac from systemic arterial pressure. Current surveillance protocols after endovascular aneurysm repair (EVAR) follow secondary markers of sac pressurization, namely, endoleak and sac enlargement. We report the first clinical experience with the use of a permanently implantable, ultrasound-activated remote pressure transducer to measure intrasac pressure after EVAR. METHODS: Over 7 months, 14 patients underwent EVAR of an infrarenal abdominal aortic aneurysm with implantation of an ultrasound-activated remote pressure transducer fixed to the outside of the stent graft and exposed to the excluded aortic sac. Twelve patients received modular bifurcated stent grafts, and 2 patients received aortouniiliac devices. Intrasac pressures were measured directly with an intravascular catheter and by the remote sensor at stent-graft deployment. Follow-up sac pressures were measured with a remote sensor and correlated with systemic arterial pressure at every follow-up visit. Mean follow-up was 2.6 +/-1.9 months. RESULTS: Excellent concordance was found between catheter-derived and transducer-derived intrasac pressssure intraoperatively. Pulsatile waveforms were seen in all functioning transducers at each evaluation interval. One implant ceased to function at 2 months of follow-up. In 1 patient a type I endoleak was diagnosed on 1-month computed tomography (CT) scans; 3 type II endoleaks were observed. Those patients with complete exclusion of the aneurysm on CT scans had a significant difference in systemic and sac systolic pressures initially (P <.001) and at 1 month (P <.001). Initial sac diastolic pressures were higher than systemic diastolic pressures (P <.001). The ratio of systemic to sac systolic pressure increased over time in those patients with complete aneurysm exclusion ( P <.001). Four of 6 patients with no endoleak and greater than 1-month follow-up had diminution of sac systolic pressure to 40 mm Hg or less by 3 months. CONCLUSION: This is the first report of a totally implantable chronic pressure transducer to monitor the results of EVAR in human beings. Aneurysm exclusion leads to gradual diminution of sac pressure over several months. Additional clinical follow-up will be necessary to determine whether aneurysm sac pressure monitoring can replace CT in the long-term surveillance of patients after EVAR.