Ultrasound elastography to quantify average percent pressure-normalized strain reduction associated with different aortic endografts in 3D-printed hydrogel phantoms.

Objective: Strain has become a viable index for evaluating abdominal aortic aneurysm stability after endovascular aneurysm repair (EVAR). In addition, literature has shown that healthy aortic tissue requires a degree of strain to maintain homeostasis. This has led to the hypothesis that too much strain reduction conferred by a high degree of graft oversizing is detrimental to the aneurysm neck in the seal zone of abdominal aortic aneurysms after EVAR. We investigated this in a laboratory experiment by examining the effects that graft oversizing has on the pressure-normalized strain ( ε ρ + ¯ /pulse pressure [PP]) reduction using four different infrarenal EVAR endografts and our ultrasound elastography technique. Approximate graft oversizing percentages were 20% (30 mm phantom-graft combinations), 30% (28 mm phantom-graft combinations), and 50% (24 mm phantom-graft combinations). Methods: Axisymmetric, 10% by mass polyvinyl alcohol phantoms were connected to a flow simulator. Ultrasound elastography was performed before and after implantation with the four different endografts: (1) 36 mm polyester/stainless steel, (2) 36 mm polyester/electropolished nitinol, (3) 35 mm polytetrafluoroethylene (PTFE)/nitinol, and (4) 36 mm nitinol/polyester/platinum-iridium. Five ultrasound cine loops were taken of each phantom-graft combination. They were analyzed over two different cardiac cycles (end-diastole to end-diastole), yielding a total of 10 maximum mean principal strain ( ε ρ + ¯ ) values. ε ρ + ¯ was divided by pulse pressure to yield pressure-normalized strain ( ε ρ + ¯ /PP). An analysis of variance was performed for graft comparisons. We calculated the average percent ε ρ + ¯ /PP reduction by manufacturer and percent oversizing. These values were used for linear regression analysis. Results: Results from one-way analysis of variance showed a significant difference in ε ρ + ¯ /PP between the empty phantom condition and all oversizing conditions for all graft manufacturers (F(3, 56) = 106.7 [graft A], 132.7 [graft B], 106.5 [graft C], 105.7 [graft D], P < .0001 for grafts A-D). There was a significant difference when comparing the 50% condition with the 30% and 20% conditions across all manufacturers by post hoc analysis (P < .0001). No significant difference was found when comparing the 20% and 30% oversizing conditions for any of the manufacturers or when comparing ε ρ + ¯ /PP values across the manufacturers according to percent oversize. Linear regression demonstrated a significant positive correlation between the percent graft oversize and the all-graft average percent ε ρ + ¯ /PP reduction ( R 2  = 0.84, P < .0001). Conclusions: This brief report suggests that a 10% increase in graft oversizing leads to an approximate 5.9% reduction in ε ρ + ¯ /PP on average. Applied clinically, this increase may result in increased stiffness in axisymmetric vessels after EVAR. Further research is needed to determine if this is clinically significant.

Early Financial Outcomes of Physician Modified Endograft Programs are Dictated by Device Cost.

INTRODUCTION: Physician-modified endografts (PMEGs) have been used for repair of thoracoabdominal aortic aneurysms (TAAAs) for 2 decades with good outcomes but limited financial data. This study compared the financial and clinical outcomes of PMEGs to the Cook Zenith-Fenestrated (ZFEN) graft and open surgical repair (OSR). METHODS: A retrospective review of financial and clinical data was performed for all patients who underwent endovascular or OSR of juxtarenal aortic aneurysms and TAAAs from January 2018 to December 2022 at an academic medical center. Clinical presentation, demographics, operative details, and outcomes were reviewed. Financial data was obtained through the institution's finance department. The primary end point was contribution margin (CM). RESULTS: Thirty patients met inclusion criteria, consisting of twelve PMEG, seven ZFEN, and eleven open repairs. PMEG repairs had a total CM of -$110,000 compared to $18,000 for ZFEN and $290,000 for OSR. Aortic and branch artery implants were major cost-drivers for endovascular procedures. Extent II TAAA repairs were the costliest PMEG procedure, with a total device cost of $59,000 per case. PMEG repairs had 30-d and 1-y mortality rates of 8.3% which was not significantly different from ZFEN (0.0%, P = 0.46; 0.0%, P = 0.46) or OSR (9.1%, P = 0.95; 18%, P = 0.51). Average intensive care unit and hospital stay after PMEG repairs were comparable to ZFEN and shorter than OSR. CONCLUSIONS: Our study suggests that PMEG repairs yield a negative CM. To make these cases financially viable for hospital systems, device costs will need to be reduced or reimbursement rates increased by approximately $8800.

Strategies to reduce rates of severe endothermal heat-induced thrombosis following radiofrequency ablation.

OBJECTIVE: Endothermal heat-induced thrombosis (EHIT) is a potential complication of radiofrequency ablation (RFA). Data on effective prophylaxis of EHIT are limited. In 2018, a high-volume, single institution implemented strategies to decrease the incidence of EHIT, including a single periprocedural prophylactic dose of low-molecular-weight heparin to patients with a great saphenous vein (GSV) diameter of ≥8 mm or saphenofemoral junction (SFJ) diameter of ≥10 mm and limiting treatment to one vein per procedure. The size threshold was derived from existing literature. The study objective was to evaluate the effects of these institutional changes on thrombotic complication rates after RFA. METHODS: A retrospective cohort control study was conducted using the Vascular Quality Initiative database. Data were collected for patients who underwent RFA with a GSV diameter of ≥8 mm or SFJ diameter of ≥10 mm from January 2015 to July 2022. The clinical end points were thrombotic complications (ie, thrombophlebitis, EHIT, deep vein thrombosis) and bleeding complications. Patient demographic and procedural variables were included in the analysis, and significant variables after univariable logistic regression were included in a multivariable logistic regression. RESULTS: After the policy change, the overall vein center EHIT rate decreased from 2.6% to 1.5%, with a trend toward significance (P = .096). The inclusion criterion of a GSV diameter of ≥8 mm or an SFJ diameter of ≥10 mm yielded 845 patients, of whom 298 were treated before the policy change and 547 after. There was a significant reduction in the rate of EHIT classified as class ≥III (2.34 vs 0.366; P = .020) after the institutional changes. Treatment of two or more veins and an increased vein diameter were associated with an increased risk of EHIT (P = .049 and P < .001, respectively). No significant association was found between periprocedural anticoagulation and all-cause thrombotic complications or EHIT (P = .563 and P = .885, respectively). CONCLUSIONS: The institutional policy changes have led to lower rates of EHIT, with a reduction in severe EHIT rates in patients with an ≥8-mm diameter GSV or a ≥10-mm diameter SFJ treated with RFA. Of the changes implemented, restricting treatment to one vein was associated with a reduction in severe EHIT. No association was found with periprocedural low-molecular-weight heparin, although a type 2 error might have occurred. Alternative strategies to prevent thrombotic complications should be explored, such as increasing the dosage and duration of periprocedural anticoagulation, antiplatelet use, and nonpharmacologic strategies.

Gore TAG thoracic branch endograft for treatment of a subacute type B aortic dissection complicated by rupture.

An 80-year-old man presented with a subacute zone 3-5 type B aortic dissection complicated by rupture and visceral and lower extremity malperfusion. He underwent emergent zone 2 repair with a Gore TAG thoracic branch endograft with inclusion of the left subclavian artery for a dominant left vertebral artery. The patient's postoperative course was uncomplicated. Type B aortic dissections can be anatomically complex, and rupture is a rare complication in the subacute phase. We report the novel use of a Gore TAG thoracic branch endograft for the management of type B aortic dissection complicated by rupture and demonstrate its feasibility for patients with type B aortic dissection complicated by rupture.

Thirty-year single-center experience with arterial thoracic outlet syndrome.

OBJECTIVE: Arterial thoracic outlet syndrome (ATOS) is rare. We present our 30-year experience with the management of ATOS at a high-volume referral center. METHODS: A retrospective review of all patients who had undergone primary operative treatment for ATOS from 1988 to 2018 was performed. ATOS was defined as subclavian artery pathology caused by extrinsic compression from a bony abnormality within the thoracic outlet. RESULTS: A total of 41 patients (45 limbs) underwent surgery for ATOS at a median age of 46 years (interquartile range [IQR], 34-58 years). Chronic symptoms (>6 weeks) were present in 31 limbs (69%). Of the 45 limbs, 13 (29%) presented with acute limb ischemia (ALI), requiring urgent brachial artery thromboembolectomy (BAT) in 9 and catheter-directed thrombolysis and thrombectomy (CDT) in 4. All patients underwent thoracic outlet decompression. 31 limbs (69%) required subclavian artery reconstruction. No perioperative deaths and only one major adverse limb event occurred. Patients with ALI underwent staged thoracic outlet decompression after initial BAT or CDT at a median of 23 days (IQR, 11-140 days). Of the 13 limbs with an initial presentation of ALI, 8 (62%) had recurrent thromboembolic events before thoracic outlet decompression subsequently requiring 10 additional BATs and 1 CDT. The cumulative probability of recurrent embolization at 14, 30, and 90 days was 8.33% (95% confidence interval [CI], 1.28%-54.42%), 16.67% (95% CI, 4.70%-59.06%), and 33.33% (95% CI, 14.98-74.20%), respectively. The median follow-up for 32 patients (35 limbs) was 13 months (IQR, 5-36 months). Subclavian artery/graft primary and secondary patency was 87% and 90%, respectively, at 5 years by Kaplan-Meier analysis. Of the 35 limbs, 5 (14%) had chronic upper extremity pain and 5 (14%) had persistent weakness. Preoperative forearm or hand pain and brachial artery occlusion were associated with chronic pain (P = .04 and P = .03) and weakness (P = .03 and P = .02). Of the 13 limbs that presented with ALI, 11 had a median follow-up after thoracic outlet decompression of 6 months (IQR, 5-14 months), including 9 (82%) with oral anticoagulation therapy. Anticoagulation therapy had no effect on subclavian artery patency (P = 1.0) or the presence of chronic symptoms (P = .93). CONCLUSIONS: The presentation of ATOS is diverse, and the diagnosis can be delayed. Preoperative upper extremity pain and brachial artery occlusion in the setting of ALI were associated with chronic pain and weakness after thoracic outlet decompression. Delayed thoracic outlet decompression was associated with an increased risk of recurrent thromboembolic events for patients who presented with ALI. An early and accurate diagnosis of ATOS is necessary to reduce morbidity and optimize outcomes.

Aneurysms of the superior mesenteric artery and its branches.

OBJECTIVE: Aneurysms of the superior mesenteric artery (SMA) and its branches are rare and account for only 6% to 15% of all visceral artery aneurysms. In the present report, we have described our 30-year experience with the management of aneurysms of the SMA and its branches at a high-volume referral center. METHODS: A retrospective review of all patients with a diagnosis of an aneurysm of the SMA or one of its branches from 1988 to 2018 was performed. Pseudoaneurysms and mycotic aneurysms were excluded. The clinical presentation, etiology, aneurysm shape and size, treatment modalities, and outcomes were analyzed. The growth rate of the aneurysms was estimated using linear regression. RESULTS: A total of 131 patients with 144 aneurysms were reviewed. The patients were primarily men (64%), with a median age of 60 years. Of the 144 aneurysms, 57 were fusiform, 30 were saccular, and 57 were dissection-associated aneurysms. Of the 131 patients, 41 had had an isolated SMA branch aneurysm. Degenerative aneurysms were the most common etiology (66%). A total of 35 patients (27%) were symptomatic at presentation. Of the 144 aneurysms, 111 had multiple computed tomography angiograms available, with a median follow-up of 43.6 months (interquartile range, 10.6-87.2 months). Only 18 aneurysms (16%) had had an estimated growth rate of ≥1.0 mm/y. The initial aneurysm size was significantly associated with the growth rate for the fusiform aneurysms (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.0-1.3]; P = .02) but not for the saccular (OR, 0.91; 95% CI, 0.76-1.1; P = 1.1) or dissection-associated (OR, 1.2; 95% CI, 0.91-1.5; P = .20) aneurysms. Acute abdominal pain (OR, 5.9; 95% CI, 1.6-22; P = .01) and chronic abdominal pain (OR, 3.7; 95% CI, 1.1-13; P = .04) were associated with aneurysm growth. Only two patients had a ruptured aneurysm, both of whom presented with rupture with no prior imaging studies. These two patients had a diagnosis of fibromuscular dysplasia and systemic lupus erythematosus, respectively. Of the 131 patients, 46 (34%) had undergone operative repair, including 36 open revascularizations and 8 endovascular procedures. The average aneurysm size for these 46 patients was 24.0 ± 8.6 mm. One patient died perioperatively, and nine patients experienced perioperative complications (25%). Of the 144 aneurysms, 91 were <20 mm, with an average size of 13.4 ± 3.1 mm. These 91 aneurysms had been followed up for a median of 120.8 months (interquartile range, 30.5-232.2 months), with no ruptures within this cohort during the follow-up period. CONCLUSIONS: The present study represents one of the largest series on aneurysms of the SMA and its branches. Our results showed that aneurysms of the SMA are relatively stable. Patients with symptomatic and fusiform aneurysms had a greater risk of growth. Aneurysms <20 mm with a degenerative etiology can be safely monitored without treatment.

Effect of obesity on radiation exposure, quality of life scores, and outcomes of fenestrated-branched endovascular aortic repair of pararenal and thoracoabdominal aortic aneurysms.

BACKGROUND: The aim of the present study was to assess the effect of obesity on procedural metrics, radiation exposure, quality of life (QOL), and clinical outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) of pararenal and thoracoabdominal aortic aneurysms. METHODS: We reviewed the clinical data from 334 patients (236 men; mean age, 75 ± 8 years) enrolled in a prospective nonrandomized study to evaluate FB-EVAR from 2013 to 2019. The patients were classified using the body mass index (BMI) as obese (BMI ≥30 kg/m2) or nonobese (BMI <30 kg/m2). QOL questionnaires (short-form 36-item questionnaire) and imaging studies were obtained preoperatively and at 2 months and 6 months postoperatively, and annually thereafter. The procedures were performed using two different fixed imaging systems. The end points included procedural metrics (ie, total operative time, fluoroscopic time, contrast volume), radiation exposure, technical success, 30-day mortality, and major adverse events, QOL changes, freedom from target vessel instability, freedom from reintervention, and patient survival. RESULTS: The aneurysm extent was a pararenal aortic aneurysm in 117 patients (35%) and a thoracoabdominal aortic aneurysm in 217 patients (65%). Both groups had similar demographics, cardiovascular risk factors, and aneurysm extent, except for a greater incidence of hyperlipidemia and diabetes among the obese patients (P < .05). No significant differences were found in the procedural metrics or intraprocedural complications between the groups, except that the obese patients had greater radiation exposure than the nonobese patients (mean, 2.5 vs 1.6 Gy; P < .001), with the highest radiation exposure in those obese patients who had undergone the procedure using system 1 (fusion alone) instead of system 2 (fusion and digital zoom; mean, 4.1 vs 1.5 Gy; P < .001). Three patients had died within 30 days (0.8%), with no difference in mortality or major adverse events between the groups. The mental QOL scores had improved in the obese group at 2 and 12 months compared with the nonobese patients, with persistently higher scores up to 3 years. At 3 years, the obese and nonobese patients had a similar incidence of freedom from target vessel instability (74% ± 6% vs 80% ± 3%; P = .99, log-rank test), freedom from reintervention (66% ± 6% vs 73% ± 4%; P = .77, log-rank test), and patient survival (83% ± 5% vs 75% ± 4%; P = .16, log-rank test). CONCLUSIONS: FB-EVAR was performed with high technical success and low mortality and morbidity, with no significant differences between the obese and nonobese patients. The procedural metrics and outcomes were similar, with the exception of greater radiation exposure among obese patients, especially for the procedures performed using system 1 with fusion alone compared with system 2 (fusion and digital zoom). Obese patients had higher QOL mental scores at 2 and 12 months, with a similar reintervention rate, target vessel outcomes, and survival compared with nonobese patients.

Are Vascular Surgery Trainees Satisfied and are They Using the Right Factors to Choose a Training Program?

BACKGROUND: Medical students and residents often evaluate training sites in vascular surgery with minimal exposure to those programs. We sought to identify factors associated with vascular surgery trainee satisfaction in relation to their current work environment and how they made their rank list. METHODS: All integrated residents and fellows currently in United States vascular training programs were queried using an anonymous electronic survey for variables of their current training environment, factors that influenced their rank order list, and satisfaction. Questions were graded on a Likert scale. Continuous, ordinal, and categorical variables were respectively analyzed using the two-sample t-test, Mann-Whitney U-test/Wilcoxon rank sum test, and Fisher's exact test. RESULTS: A total of 166 of 517 (32%) trainees completed the survey with equal distribution across postgraduate years. Respondents reported high rates of satisfaction with their training program overall (84%), including 88% (n = 83) of residents and 78% (n = 56) of fellows. Several work environment variables were associated with both resident and fellow satisfaction including program-funded trips for conferences and presentations (P = 0.027 for residents; P = 0.001 for fellows), diversity of operative cases (P = 0.024; P < 0.001), perception of a strong supportive social network at the hospital (P = 0.006; P = 0.001), and perception of appreciation by attending surgeons (P < 0.001; P < 0.001). Fellows who felt appreciated by nursing staff (P = 0.047), ancillary staff (P = 0.013), and patients were more likely to be satisfied (P = 0.011); however, this was not true for integrated residents. Social outings with nontrainee family and friends were associated with satisfaction for fellows (P = 0.002) but not integrated residents (P = 0.138), whereas social outings with vascular trainees were associated with satisfaction for integrated residents (P = 0.047) but not fellows (P = 0.375). Similarly, satisfied integrated residents were more likely to have close relationships with their vascular cotrainees (P = 0.035) than fellows (P = 0.349). No rank list factors were found to be predictive of current trainee satisfaction for integrated residents. Rank list factors associated with fellow satisfaction included recommendation of the institution from a mentor (P < 0.001), success of program graduates (P = 0.002), faculty (P = 0.014), perceived program prestige (P = 0.040), and amount of early operative exposure (P = 0.042). CONCLUSIONS: Vascular surgery trainees report a high level of satisfaction with their training program. Fellow satisfaction was more dependent on the perception of their workplace peers than integrated residents. Satisfied integrated residents were more likely to have close relationships with their vascular cotrainees than fellows.

A Mycotic Common Iliac Artery Pseudoaneurysm of Indeterminate Etiology.

We present the unusual case of a mycotic right common iliac artery pseudoaneurysm caused by the methicillin-susceptible Staphylococcus aureus (MSSA) of indeterminate etiology in a healthy 57-year-old man with no risk factors for infection, trauma, or malignancy. The patient initially presented with worsening subacute right lower quadrant pain and was found to have a pseudoaneurysm of the right common iliac artery. Given concern for rupture on a computed tomography angiogram (CTA), he underwent exclusion of the pseudoaneurysm with a covered stent. At the time of presentation, he had no signs or symptoms of infection. However, the patient developed fever, chills, and worsening right lower quadrant pain 13 days after the index operation and was found to have a leukocytosis, blood cultures positive for MSSA, and progressive soft-tissue changes involving the right common iliac artery on CTA consistent with infection. He was definitively treated with stent explantation, aggressive debridement and replacement with an in situ cryopreserved bypass, and short-term suppressive antibiotic therapy.

Common Femoral Artery Access on YouTube: What Practices are Being Shown and Who is Delivering the Message?

OBJECTIVES: Novice learners are increasingly turning to YouTube as a learning resource for surgical procedures. One example of such a procedure is common femoral artery puncture and sheath placement. Practitioners in several specialties perform this procedure to access the arterial system for angiography and intervention. We set forth to compare the techniques demonstrated on YouTube by the various specialists, as well as compare each specialty׳s prevalence on this website. METHODS: YouTube (www.youtube.com) was accessed in December 2015 at multiple time points with a cleared-cache web browser for the keyword search categories: "femoral artery access," "femoral access," and "angiography access." The top 500 videos from each of these keyword searches were analyzed. Videos were categorized by practitioner specialty, technique, duration of video, age of video, and total views. Videos with clear demonstration of femoral artery access were included in the analysis. All industry videos were excluded from the analysis. Categorical variables were compared using Fisher׳s exact test, and continuous variables were compared with the Student׳s t-test. RESULTS: A total of 2460, 4680 and 1800 videos were found for each keyword search, respectively. Of these, 33 videos clearly demonstrated femoral artery access technique. Vascular specialists, compared to interventional cardiology and radiology, had fewer videos (n = 4 vs. 14) and older videos (3.5 ± 2.1y vs. 2.25 ± 0.5y, p < 0.05). The vascular specialists demonstrated ultrasound-guided access, while interventional cardiology predominantly demonstrated landmark-guided access (p < 0.05). CONCLUSIONS: Although YouTube and other online resources are being used by novice learners, vascular specialists are underrepresented for femoral artery access, a foundational vascular procedure. Other practitioners demonstrate videos with landmark-guided access and rarely demonstrate ultrasound use. As recognized vascular experts, vascular surgeons should improve their visibility in online learning resources.