Percutaneous Aortoiliac Thromboendarterectomy for Acute Limb Ischemia.

Aortoiliac occlusive disease (AIOD) can occur from either chronic, progressive atherosclerotic disease, acute on chronic thrombosis or acute arterial embolism, and can all result in limb ischemia. Bypass surgery had long been the gold standard for treatment for AIOD, however, with advances in endovascular techniques, minimally invasive treatment of aortoiliac lesions has become the first line choice of management in many cases. Herein, we describe a case of utilizing the Inari ClotTriever to perform aortoiliac mechanical thrombectomy and the ARTIX thrombectomy system to perform an embolectomy the superficial femoral artery, highlighting new therapies to treat AIOD.

Traumatic Iliac Arteriovenous Fistula Treated With the Amplatzer Vascular Plug II: A Case Report and Literature Review.

Traumatic iliac arteriovenous fistula is a rare complication of vascular injury. Open surgical repair has an incidence of postoperative complications. In recent years, endovascular treatment has shown better efficacy. We report a 62-year-old female AVF patient with a stab injury history of more than 16 years. Computed tomography angiography (CTA) revealed a large arteriovenous fistula between the right internal iliac artery and the common iliac vein. After considering the patient's relevant conditions, an endovascular approach was satisfactorily performed with the implantation of an Amplatzer Vascular Plug II to interrupt the abnormal vascular communication and maintain arterial and venous patency. The final control images showed closure of the arteriovenous communication.

Ex vivo Akt inhibition reverses castration induced internal pudendal artery and penile endothelial dysfunction.

AIMS: Androgen deprivation therapy is a common prostate cancer treatment which causes men to have castrate levels of testosterone. Unfortunately, most testosterone deficient patients will suffer severe erectile dysfunction (ED) and have no effective ED treatment options. Testosterone deficiency causes endothelial dysfunction and impairs penile vasodilation necessary to maintain an erection. Recent evidence demonstrates testosterone activates androgen receptors (AR) and generates nitric oxide (NO) through the Akt-endothelial NO synthase (eNOS) pathway; however, it remains unknown how castration impacts this signaling pathway. MATERIALS AND METHODS: In this study, we used a surgically castrated rat model to determine how castration impacts ex vivo internal pudendal artery (IPA) and penile relaxation through the Akt-eNOS pathway. KEY FINDINGS: Unlike systemic vasculature, castration causes significant IPA and penis endothelial dysfunction associated with a 50% AR reduction. Though testosterone and acetylcholine (ACh) both phosphorylate Akt and eNOS, castration did not affect testosterone-mediated IPA and penile Akt or eNOS phosphorylation. Surprisingly, castration increases ACh-mediated Akt and eNOS phosphorylation but reduces the eNOS dimer to monomer ratio. Akt inhibition using 10DEBC preserves IPA eNOS dimers. Functionally, 10DEBC reverses castration induced ex vivo IPA and penile endothelial dysfunction. SIGNIFICANCE: These data demonstrate how castration uncouples eNOS and provide a novel strategy for improving endothelial-dependent relaxation necessary for an erection. Further studies are needed to determine if Akt inhibition may treat or even prevent ED in testosterone deficient prostate cancer survivors.

US Velocimetry in Participants with Aortoiliac Occlusive Disease.

Background The accurate quantification of blood flow in aortoiliac arteries is challenging but clinically relevant because local flow patterns can influence atherosclerotic disease. Purpose To investigate the feasibility and clinical application of two-dimensional blood flow quantification using high-frame-rate contrast-enhanced US (HFR-CEUS) and particle image velocimetry (PIV), or US velocimetry, in participants with aortoiliac stenosis. Materials and Methods In this prospective study, participants with a recently diagnosed aortoiliac stenosis underwent HFR-CEUS measurements of the pre- and poststenotic vessel segments (August 2018 to July 2019). Two-dimensional quantification of blood flow was achieved by performing PIV analysis, which was based on pairwise cross-correlation of the HFR-CEUS images. Visual inspection of the entire data set was performed by five observers to evaluate the ability of the technique to enable adequate visualization of blood flow. The contrast-to-background ratio and average vector correlation were calculated. In two participants who showed flow disturbances, the flow complexity and vorticity were calculated. Results Thirty-five participants (median age, 67 years; age range, 56-84 years; 22 men) were included. Visual scoring showed that flow quantification was achieved in 41 of 42 locations. In 25 locations, one or multiple issues occurred that limited optimal flow quantification, including loss of correlation during systole (n = 12), shadow regions (n = 8), a short vessel segment in the image plane (n = 7), and loss of contrast during diastole (n = 5). In the remaining 16 locations, optimal quantification was achieved. The contrast-to-background ratio was higher during systole than during diastole (11.0 ± 2.9 vs 6.9 ± 3.4, respectively; P < .001), whereas the vector correlation was lower (0.58 ± 0.21 vs 0.47 ± 0.13; P < .001). The flow complexity and vorticity were high in regions with disturbed flow. Conclusion Blood flow quantification with US velocimetry is feasible in patients with an aortoiliac stenosis, but several challenges must be overcome before implementation into clinical practice. Clinical trial registration no. NTR6980 © RSNA, 2021 Online supplemental material is available for this article.

Effects of nonselective internal iliac artery angioembolization on pelvic venous flow in the swine model.

BACKGROUND: Pelvic angioembolization (AE) is a mainstay in the treatment algorithm for pelvic hemorrhage from pelvic fractures. Nonselective AE refers to embolization of the bilateral internal iliac arteries (IIAs) proximally rather than embolization of their tributaries distally. The aim of this study was to quantify the effect of nonselective pelvic AE on pelvic venous flow in a swine model. We hypothesized that internal iliac vein (IIV) flow following IIA AE is reduced by half. METHODS: Nine Yorkshire swine underwent nonselective right IIA gelfoam AE, followed by left. Pelvic arterial and venous diameter, velocity, and flow were recorded at baseline, after right IIA AE and after left IIA AE. Linear mixed-effect model and signed rank test were used to evaluate significant changes between the three time points. RESULTS: Eight swine (77.8 ± 7.1 kg) underwent successful nonselective IIA AE based on achieving arterial resistive index of 1.0. One case was aborted because of technical difficulties. Compared with baseline, right IIV flow rate dropped by 36% ± 29% (p < 0.05) and 54% ± 29% (p < 0.01) following right and left IIA AE, respectively. Right IIA AE had no initial effect on left IIV flow (0.37% ± 99%, p = 0.95). However, after left IIA AE, left IIV flow reduced by 54% ± 27% (p < 0.01). Internal iliac artery AE had no effect on the external iliac arterial or venous flow rates and no effect on inferior vena cava flow rate. CONCLUSION: The effect of unilateral and bilateral IIA AE on IIV flow appears to be additive. Despite bilateral IIA AE, pelvic venous flow is diminished but not absent. There is abundant collateral circulation between the external and internal iliac vascular systems. Arterial embolization may reduce venous flow and improve on resuscitation efforts in those with unstable pelvic fractures. LEVEL OF EVIDENCE: Prognostic, level IV.

Outcomes of Hypogastric Coverage and Occlusion during Endovascular Treatment of Aortoiliac Occlusive Disease.

BACKGROUND: The risk of hypogastric occlusion (HO) following bare-metal stent (BMS) coverage of the hypogastric origin during endovascular treatment of aortoiliac occlusive disease (AIOD) is unclear. This study sought to determine the rate and clinical significance of HO following BMS coverage during iliac stenting for complex AIOD. METHODS: Consecutive patients undergoing elective iliac stenting for AIOD from 2010-2018 at Cleveland Clinic were reviewed. Patients with BMS coverage of a patent hypogastric origin were included. Rate of HO were determined by review of intraoperative angiography and follow up imaging. Predictors of HO were identified by univariable and multivariable logistic regression. Outcomes were compared between those who did and did not develop HO. RESULTS: There were 251 patients (338 limbs) with BMS coverage of the hypogastric origin during treatment of AIOD. Lesion severity was classified as TASC C/D in 249/338 (73.7%) of cases. Bilateral hypogastric coverage occurred in 93/251 (37.1%) patients. Hypogastric patency was 78.1% at 24-months following coverage. Recanalization of an ipsilateral external iliac artery (EIA) occlusion was predictive of HO (HR 3.12, 95% CI: 1.33, 7.34; P= 0.009). Increased luminal diameter of the hypogastric origin protected against HO (HR 0.64; 95% CI: 0.47, 0.88; P= 0.006). Perioperative outcomes were no different between patients with and without HO. There were no cases of gluteal necrosis, spinal cord ischemia, or pelvic organ ischemia. Four-year mortality and limb salvage were not affected by HO. HO was associated with decreased primary patency of ipsilateral iliac stents and increased risk of ipsilateral reintervention (HR 5.49; 95% CI: 1.82, 16.58; P= 0.002). CONCLUSIONS: HO is relatively infrequent following BMS coverage during treatment of AIOD. Luminal diameter of the hypogastric origin and ipsilateral EIA occlusion are associated with occlusion. HO is well tolerated in AIOD, though it is potentially associated with increased risk iliac stent occlusion and reintervention.

Thrombosis of external iliac and common femoral arteries secondary to blunt trauma due to handlebar injury.

BACKGROUND: Vascular injuries are uncommon following a bicycle handlebar injury in children. However, they are associated with an extremely high morbidity including limb loss and asymmetric limb growth. CASE PRESENTATION: 11 year old previously healthy female who presented to a pediatric emergency department immediately after sustaining blunt trauma to her abdomen by a bicycle handlebar. She complained of pain in her right lower extremity without paresthesia and was noted to have a painful superficial laceration to the right lower abdomen with tenderness on palpation. The extremity was noted to be mottled, cool to touch, with decreased sensations and delayed capillary refill but intact motor function. The peripheral pulses in the extremity were noted to be absent on exam, which was confirmed by a bedside Doppler. A Computed Tomography Angiography (CTA) of the abdomen and pelvis revealed an occluding thrombus in the external iliac and right common femoral arteries which required surgical repair. She subsequently developed occlusion secondary to traumatic dissection and compartment syndrome in the same extremity requiring repeat surgical intervention. CONCLUSION: In managing patients with blunt force trauma to the abdomen from handlebars, clinicians should have a high index of suspicion for vascular injuries even with low-risk mechanism of injury and superficial injuries noted on exam. Their assessment should include immediate examination of bilateral peripheral pulses of the lower extremities to evaluate for clinical findings associated with acute lower limb ischemia as well as bedside Doppler exams and early consideration of CTA to assess for occult vascular injury.

Conformability of the GORE EXCLUDER iliac branch endoprosthesis is associated with freedom from adverse iliac events.

OBJECTIVE: The GORE EXCLUDER iliac branch endoprosthesis (IBE; W.L. Gore & Associates, Flagstaff, Ariz) is designed to preserve internal iliac artery (IIA) patency during endovascular treatment of aneurysms involving the common iliac artery. The device is intended to conform to iliac tortuosity, which may decrease adverse iliac events (AIE). The objective of this study was to evaluate risk factors for AIE after IBE implantation. METHODS: This was a post hoc analysis of the prospective, multicenter GORE 12-04 IBE pivotal trial. Patients with preoperative and postoperative axial imaging were included, with analysis based on each treated iliac system. An independent core laboratory performed all scan measurements, including iliac diameters, lengths, and tortuosity. Conformability was analyzed by the changes in tortuosity after IBE deployment, with less change indicating greater conformation. The end point was AIE, defined as ipsilateral radiographic or clinical complications. Critical nonconformation was defined as a threshold change in tortuosity associated with a significant increase in AIE. RESULTS: We included 98 patients with 101 treated iliac systems. There were eight AIE (8%; six IIA component occlusions, one iliac branch component occlusion, and one EIA dissection requiring reintervention). Patients with AIE had smaller IIA diameters and less IBE conformability. After multivariable logistic regression analysis, an IIA diameter of less than 10 mm and a change in total iliac tortuosity beyond -15% were independently associated with AIE (odds ratio, 12 [interquartile range, 1.4-110] and odds ratio, 8.2 [interquartile range, 1.5-46], respectively), and the latter was used to define critical nonconformation. Critical nonconformation occurred in 11% of treated systems, and was associated with a high rate of AIE (36% vs 4%; P = .004). CONCLUSIONS: Endograft conformation is a novel device property and technical outcome that, along with a larger IIA diameter, is associated with freedom from AIE after IBE deployment. An evaluation of these risk factors may better inform the management of patients with iliac aneurysmal disease. Further research on endograft conformation and patient outcomes is warranted, particularly for those with challenging anatomy undergoing complex procedures.

Limb Occlusion Rate after EVAR With Individualized Graft Limb Selection and a Liberal Protocol of Primary Relining.

BACKGROUND: This study analyses limb occlusion rates after endovascular aneurysm repair (EVAR) with a strategy including stent-graft limb selection and liberal primary stenting (relining) in anatomies at higher risk for occlusion with uncovered self-expandable or balloon-expandable stents. METHODS: All patients undergoing elective EVAR with a bifurcated stent-graft between January 2010-August 2018 were included. A protocol involving personalized stent-graft selection and liberal primary relining based on preoperative imaging was followed during the whole period. Primary endpoints were technical success and primary limb patency during follow-up. Secondary endpoints included mortality and limb reintervention rates. Risk factors associated to limb patency and reintervention rates were analyzed. RESULTS: Six hundred and fifteen patients (548 males; mean age 72.9 ± 9 years) were included. Overall technical success was 98.5% (606/615). One (0.16%) patient died during the first 30 days. Of the 1230 limbs, 96 (8%) were deemed at risk for occlusion in view of the anatomy, and primarily relined in 62 patients. Estimated primary limb patency at 6 months, 1 year and 3 years was 99.5 ± 0.2%, 99.2 ± 0.3% and 98.5 ± 0.5%, respectively. Freedom from limb-related reintervention at 6 months, 1 year and 3 years was 98.1 ± 0.4%, 97.4 ± 0.5% and 95.6 ± 0.7%, respectively. Only one (1%) of the 96 relined limbs occluded during follow-up. No differences were found in terms of patency or freedom from reintervention between limbs at risk that were primary stented and limbs without adjunctive stents. Gore Excluder stent-grafts presented better patency (Breslow P = 0.005) and lower reintervention rates (Breslow P = 0.001) than other devices during follow-up. Peripheral artery disease was also a risk factor for reintervention (Breslow P = 0.015). CONCLUSION: Liberal use of primary limb relining in patients with iliac anatomy at higher risk for occlusion appears to be a safe and effective strategy to preserve limb patency after EVAR. Gore Excluder graft limbs present better patency and lower reintervention rates than other stent-graft types.

Automated Image Fusion Guidance during Endovascular Aorto-Iliac Procedures: A Randomized Controlled Pilot Study.

BACKGROUND: The benefits of imaging guidance using a new fully automated fusion process (CYDAR) have been demonstrated during endovascular aortic aneurysm repair, but little is known about its use during aorto-iliac occlusive disease endovascular revascularization. The aim of this study was to evaluate the influence of CYDAR image fusion guidance during endovascular treatment of symptomatic aorto-iliac occlusive lesions, compared with control patients treated using standard 2D fluoroscopy alone. METHODS: This is a single-center randomized controlled pilot study that recruited patients undergoing aorto-iliac endovascular revascularization. RESULTS: Between January 2019 and February 2020, 37 patients with symptomatic aorto-iliac lesions were enrolled: 18 were assigned to the fusion group and 19 to the control group. Patients and lesions characteristics were well balanced between both study groups. The technical success of the procedure was 100% in the Fusion group and 94% in the control group. All radiation-related parameters were lower in the fusion compared to the control group, including: median DAP 18.5 Gy.cm2 vs. 21.8 Gy.cm2; Air Kerma 0.10 Gy vs. 0.12 Gy; fluoroscopy dose 4.2 Gy.cm2 vs. 5.1 Gy.cm2; and number of DSA 7.5 vs. 8. The volume of iodinated contrast used was higher in the fusion group: 41 mL vs. 30 mL. The total procedure time was the same in both groups:60 min vs. 60 min. CONCLUSIONS: The results of this pilot study suggest the use of fusion imaging in endovascular treatment of aorto-iliac disease results in reduction in radiation-related measured parameters with no change in procedure time and higher doses of iodinated contrast used. These results need to be further investigated in a larger, adequately powered study.

Covered Stents for Endovascular Treatment of Aortoiliac Occlusive Disease: A Systematic Review and Meta-Analysis.

PURPOSE: The treatment of aortoiliac occlusive disease (AIOD) has largely shifted to endovascular techniques, with primary stenting constituting the preferred treatment approach. The goal of the current study was to summarize available literature and to determine whether covered stents are superior to bare metal stents for the treatment of AIOD, in terms of both periprocedural and long-term outcomes. METHODS: A meta-analysis of 47 studies was conducted with the use of random effects modeling. The incidence of adverse events during follow up among the individual included studies was synthesized. RESULTS: Most of the lesions were located at the common iliac arteries and were chronic total occlusions. The procedure was technically successful in almost all cases in both groups, with a low rate of periprocedural complications observed in both groups. The reported primary patency rates for the non-covered and covered stent group during an average follow up of 24.3 months among the individual studies, were 84% and 92% respectively, while surgical or endovascular re-intervention was required in 10% of non-covered stent cases and in 6% of covered stent cases. Eight studies comparing covered vs non-covered stents in terms of patency demonstrated superiority of covered stents (OR: 2.47; 95% CI: 1.01-6.01; p = 0.047 Combining TASC C/D lesions together 12 studies reported 92% (95%CI:89%-95%) primary patency in the covered stent group, while 7 studies reported 75% (95%CI: 60%-88%) primary patency for cases treated with non-covered stents. CONCLUSION: This study demonstrated that covered stents are safe and effective when utilized for the treatment of AIOD. Covered stents were associated with a statistically significant higher odds of primary patency in both the overall cohort and in more complex TASC C/D lesions. However, additional high-quality comparative analyses between covered vs bare metal stents and between several types of covered stents are needed to determine the most optimal treatment modality for AIOD.

Symptomatic Diaphragmatic Hernia after Thoracofemoral Bypass.

Despite its relative underutilization in the primary management of aortoiliac occlusive disease, thoracofemoral bypass is an attractive extra-anatomic surgical option in select patients. Thoracofemoral bypass classically entails passing a graft from the left chest into the retroperitoneal space through a small opening created in the diaphragm. While theoretically possible that this maneuver may predispose to a peri-graft diaphragmatic hernia, currently there are no cases of this complication reported in the literature, nor has its surgical repair been described. This case illustrates the rare complication of symptomatic diaphragmatic hernia following a thoracobifemoral bypass.

Opposing Responses of the Calcium Channel Blocker Nicardipine to Vascular Stiffness in the Elastic and Muscular Arteries in Rabbits.

AIM: The cardio-ankle vascular index (CAVI) consists of intrinsic and functional arterial stiffness mainly regulated by vasoactive compounds. A new stiffness index of the aorta (aBeta) and iliac-femoral arteries (ifBeta) was determined by applying the CAVI theory to the whole aorta and iliac-femoral arteries. We investigated the changes in aBeta and ifBeta in response to decreased blood pressure (BP) induced by the Ca2＋ channel blocker nicardipine to elucidate the involvement of Ca2＋ in aBeta and ifBeta. METHODS: Pressure waves at the origin of the aorta (oA), distal end of the abdominal aorta (dA), and left femoral artery (fA) as well as flow waves at the oA were simultaneously recorded before and after the infusion of nicardipine (50 µg/kg/min) for 2 min in 12 male rabbits under pentobarbital anesthesia. Beta was calculated using the following formula: Beta=2ρ / PP×ln (SBP / DBP)×PWV2, where ρ, SBP, DBP, and PP denote blood density and systolic, diastolic, and pulse pressures, respectively. aBeta, ifBeta, and aortic-iliac-femoral Beta (aifBeta) were calculated using aPWV, ifPWV, and aifPWV, respectively. RESULTS: SBP, mean arterial pressure (MAP), DBP, and total peripheral vascular resistance significantly decreased during the administration of nicardipine, whereas cardiac output significantly increased. aBeta and ifBeta significantly increased and decreased, respectively, whereas aifBeta did not change despite the decrease in BP. ifBeta and aBeta positively and negatively correlated with BP, respectively, whereas aifBeta did not correlate with SBP. CONCLUSIONS: There were contradictory arterial responses to nicardipine between the elastic and muscular arteries. Unknown vasoconstriction mechanisms that are not involved in Ca2＋ influx may function in the aorta in response to decreased BP.

Aorto-iliac peripheral artery disease.

Aorto-iliac disease is a common manifestation of atherosclerosis. Individuals with this condition are at heightened cardiovascular risk, and may have limb symptoms ranging from claudication to limb-threatening ischemia. A regimen of medical therapy, risk factor modification, and exercise is first line therapy. Revascularization is reserved for individuals with lifestyle-limiting claudication despite conservative therapy and in those with chronic limb-threatening ischemia. Multiple endovascular therapies are now available that enable even the most complex aorto-iliac lesions to be approached and treated with safe and durable results.

Prinzmetal-Like Acute Limb Ischemia.

Vasospasm-induced acute limb ischemia (ALI), also known as vasospastic limb ischemia (VLI), is a rare, underreported vascular event. Unlike thrombotic and embolic occlusive etiologies, which often warrant revascularization, vasospasm is a transient phenomenon that may be successfully managed conservatively without surgical intervention. Thus, prompt recognition and accurate diagnosis of VLI is imperative to avoid unnecessary surgical or endovascular procedures. This diagnosis, however, can pose as a challenge for clinicians, as it can present with clinical signs and symptoms near-identical to the presentation of thrombotic-induced ALI. In this report, we present a patient that experienced 2 vasospasm-induced ischemic events; the patient developed Rutherford IIb acute limb-threatening ischemia following cardiac catheterization for myocardial infarction. Computer tomography angiography findings of her right leg revealed acute occlusion suggesting the need for immediate operative intervention for limb salvage. However, due to her critical state, she instead was managed with medical treatments. Despite no intervention, the patient had full resolution of her right leg symptoms. We present this case to highlight the unusual multifocality of vasospastic events and to increase awareness of the diagnostic challenges associated with VLI.

Eversion Endarterectomy of the External Iliac Artery in Treating Chronic Limb-Threatening Ischemia in TASC II C and D Iliofemoral Occlusive Disease.

BACKGROUND: Endovascular treatment of iliofemoral occlusive disease is a challenging approach, especially for TransAtlantic Inter-Society C and D lesions. Therefore, the revascularization procedure in such situations is preferably performed by bypass graft surgery with synthetic materials. The purpose of this study is to report the feasibility and mid-term results of eversion endarterectomy of the external iliac artery (EEEIA), as an alternative autologous option. METHODS: Retrospective study with 18 EEEIA performed between September 2015 and February 2020, exclusively for chronic limb-threatening ischemia treatment in patients with increased risk of postoperative surgical infection and inadvisable for endovascular treatment. Demographic, clinical variables and outcomes were collected from a prospective database. The main end points are: amputation-free survival (AFS) and 30-day mortality. Secondary end points include: primary patency (PP), cumulative patency (CP), overall survival (OS), and postoperative surgical complication. Kaplan-Meier analysis was used to estimate cumulative time of outcomes. RESULTS: The mean age was 64.8 ± 8.3 years, with predominance of men. The median follow-up period was 1012 days, 95% confidence interval [119, 1365] days. Most had Rutherford 5 (n = 13, 72.2%) and mean ankle brachial index was 0.38 ± 0.22. The PP, CP, AFS, and OS in 730 days were 81%, 92%, 80%, and 88%, respectively. There was no 30-day mortality or postoperative surgical infection. CONCLUSIONS: Iliofemoral reconstruction through EEEIA is an effective surgical procedure with good patency rates, AFS and OS. In addition, it can be considered an useful and safe option, especially in cases in which a prosthesis should be avoided.

The Successful Treatment of an Ilio-Iliac Fistula and Aneurysms Affecting the Abdominal Aortic and Iliac Arteries via Endovascular Stent Graft Repair.

Spontaneous ilio-iliac arteriovenous fistula (AVF) associated with aneurysms affecting the abdominal aortic and iliac arteries is a rare condition. The classical clinical symptoms of ilio-iliac AVF include high-output heart failure, abdominal pain, abdominal bruits and thrills, a pulsatile abdominal mass, and venous congestion symptoms (leg edema and hematuria). The prompt repair of AVF is necessary to restore the patient's hemodynamics. We report a case in which a patient with aneurysms affecting the abdominal aortic and iliac arteries and an ilio-iliac AVF presented with high-output heart failure and leg ischemia and was successfully treated via endovascular stent graft repair.