Snare-Dragging Technique to Target the Hypogastric Artery in an Iliac Bifurcation Dissection.

PURPOSE: To describe snare-assisted vessel targeting to selectively overcome a dissection in the iliac bifurcation and gain antegrade access to the hypogastric artery (HA). TECHNIQUE: The technique is demonstrated in a 64-year-old woman with an asymptomatic Crawford type III thoracoabdominal aneurysm. A 2-stage endovascular repair, consisting of a thoracic endovascular aortic repair (TEVAR) and a branched endovascular aortic repair was planned. In the control angiography after TEVAR, a disrupted plaque with consequent dissection in the right iliac bifurcation was detected. The perfusion of the common iliac artery and external iliac artery resulted impaired. The targeting of the right HA through a contralateral antegrade approach failed, whereas an ipsilateral retrograde approach was possible but unsuitable for therapeutic purposes. Using the catheter of the retrograde ipsilateral access, a snare from a contralateral crossover was cached and dragged into the HA, allowing the targeting of the vessels and further endovascular therapy with angioplasty and stenting. Follow-up 8 months postoperatively demonstrated the patency of the stents and well-preserved perfusion in the right iliac bifurcation. CONCLUSION: The snare-dragging technique can be used to gain access to vessels presenting challenging conformations or dissections. This application may be a valuable support for complex endovascular treatment in a variety of patients. CLINICAL IMPACT: The snare-dragging technique can be used to gain access to vessels presenting challenging conformations or dissections. It allows the catheterization to be establish from the easiest and safest approach and then "transferred" from one access to the other. It avoids the risk of repeated loss of catheterization due to unstable and unfavorable working angles, and it saves time and radiation. It permits different material combinations, adapting to the available resources and materials. We believe that the current technique may increase the strategy spectrum available for endovascular therapy and complex endovascular procedures.

Results of Iliac Branch Devices in Octogenarians Within the pELVIS Registry.

Purpose: To evaluate if the elderly could benefit from the implantation of iliac branch devices (IBDs) to preserve the patency of the internal iliac artery (IIA) in aneurysms involving the iliac bifurcation. Materials and Methods: From January 2005 to April 2017, 804 patients enrolled in the pELVIS registry underwent endovascular aneurysm repair with 910 IBDs due to aneurysmal involvement of the iliac bifurcation. Among the 804 patients, 157 (19.5%) were octogenarians (mean age 82.9±2.5 years; 157 men) with 171 target IIAs for preservation. Outcomes at 30 days included technical success, death, conversion to open surgery, and major complications. Outcomes evaluated in follow-up were patency of the IBD and target vessels, type I and type III endoleaks, aneurysm-related reinterventions, aneurysm-related death, and overall patient survival. Kaplan-Meier analyses were employed to evaluate the late outcome measures; the estimates are presented with the 95% confidence interval (CI). Results: Technical success was 99.4% with no intraoperative conversions or deaths (1 bridging stent could not be implanted, and the IIA was sacrificed). Perioperative mortality was 1.9%. The overall perioperative aneurysm-related complication rate was 8.9% (14/157), with an early reintervention rate of 5.1% (8/157). Median postoperative radiological and clinical follow-up were 21.8 months (range 1-127) and 29.3 months (range 1-127), respectively. Estimated rates of freedom from occlusion of the IBD, the IIA, and the external iliac artery at 60 months were 97.7% (95% CI 96.1% to 99.3%), 97.3% (95% CI 95.7% to 98.9%), and 98.6% (95% CI 97% to 99.9%), respectively. Estimated rates of freedom from type I and type III endoleaks and device migration at 60 months were 90.9% (95% CI 87% to 94.3%), 98.7% (95% CI 97.5% to 99.8%), and 98% (95% CI 96.4% to 99.6%), respectively. Freedom from all cause reintervention at 60 months was 87.4% (95% CI 82.6% to 92.2%). The estimated overall survival rate at 60 months was 59% (95% CI 52.4% to 65.6%). Conclusion: IBD implantation in octogenarians provided acceptable perioperative mortality and morbidity rates, with satisfying long-term freedom from IBD-related complications and should be considered a feasible repair option for selected elderly patients affected by aneurysms involving the iliac bifurcation.

Endovascular reconstruction of iliac artery bifurcation atherosclerotic disease with the kissing technique.

A 71-year-old male patient with severe left buttock and lower-extremity claudication due to iliac artery bifurcation stenoses was referred to our institution for endovascular treatment. A 'kissing' technique was used in order to dilate the proximal parts of both internal and external iliac arteries and avoid compromization of the internal iliac artery during proximal external iliac artery stenting. A balloon expandable stent was inserted via a left ipsilateral retrograde access to the narrowed origin of the left external iliacartery and a balloon catheter via a right contralateral access inside the origin of the left internal iliac artery. Simultaneous balloons inflation restored full patency of both vessels. Twelve months later the patient is doing well, free of buttock or lower-extremity claudication symptoms. For iliac artery bifurcation atherosclerotic disease, endovascular repair with the 'kissing' technique can achieve a complete bifurcation reconstruction offering significant clinical benefit in selected patients.

Branched endovascular iliac artery repair using the Zenith® Branch Endovascular Iliac Bifurcation graft: outcomes and reinterventions in our retrospective cohort.

Background: The aim of this retrospective cohort study was to analyze the outcomes and the need for reinterventions following branched iliac artery repair using the Zenith® Branch Endovascular Iliac Bifurcation (ZBIS; Cook Medical Europe LTD, Limerick, Ireland) graft. Methods: Patient characteristics and follow-up data on 63 patients following branched iliac artery repair using the ZBIS device were evaluated and compared between patients with and without iliac reinterventions. A competing risk regression model was analyzed to identify independent predictors of reinterventions, and to predict the reintervention risk. Results: ZBIS implantation's technical success rate was 100%, and we observed no in-hospital mortality. Internal iliac artery patency was 93% during a median [first quartile, third quartile] follow-up of 19 [5, 39] months. Thirty-two iliac reinterventions were performed in 23 patients (37%) after a mean time of 3.0 months (IQR: 0.4-6.8) (time to first reintervention). Endoleaks type I and II were the most common indication for reinterventions (n=14, 61%). The internal iliac artery's diameter [subdistribution hazard ratio (sHR): 1.046; P=0.0015] and a prior abdominal aortic intervention (sHR: 0.3331; P=0.0370) were identified as significant variables in the competing risk regression model for a reintervention. The risk for reintervention was 33% (95% CI: 20-46%), and 46% (95% CI: 28-63%) after 12 and 36 months, respectively. Conclusions: Endovascular repair of degenerative iliac artery aneurysms with Zenith Branch Iliac Bifurcation device is a feasible and safe option. Perioperative morbidity and mortality are low with good graft patency rates. The risk for secondary iliac artery interventions is considerable and highlights the need for patients with iliac disease to undergo continuous follow-up in a dedicated vascular center.

Midterm result of custom-made iliac branch device for common iliac aneurysm with and without abdominal aortic aneurysm.

OBJECTIVES: Although commercial iliac branch devices offer a new and valid endovascular approach to treating iliac aneurysm and effectively preserve antegrade flow of the internal iliac artery, their use may not be suited for all types of challenging anatomy, especially isolated common iliac artery aneurysm. Our custom-made iliac bifurcation device has a unique design and excludes both combined and isolated iliac branch aneurysm. This study validated the efficacy and safety of the custom device by comparing clinical outcomes between groups receiving commercial and custom devices. METHODS: Data of consecutive patients receiving iliac bifurcation device implantation for iliac aneurysm with or without concomitant endovascular repair for abdominal aortic aneurysm from January 2010 to May 2019 were reviewed. RESULTS: Iliac bifurcation device implantation with or without concomitant abdominal aortic aneurysm stent grafting was completed in 46 patients (commercial, n = 35; custom, n = 11). No significant differences were observed regarding postoperative complications, occlusion or endoleak. Comparisons of primary (80.8% vs 85.7%, P = 0.88) and secondary (86.5% vs 85.7%, P = 0.85) patency and freedom from reintervention (88.2% vs 100%, P = 0.33), all-cause mortality (78.6% vs 100%, P = 0.25) and aneurysm-related mortality (100% vs 100%, P = 1.00) also indicated no differences at a 5-year surveillance point. Furthermore, the iliac aneurysms of the groups displayed similar shrinkage 1 year after procedures. CONCLUSIONS: For iliac aneurysm, the novel custom-made iliac bifurcation device is an adaptable design not inferior to commercial devices with regard to postoperative complications, bridge occlusion, endoleak and short-term aneurysm remodelling. It provides an alternative for treatment, particularly when certain anatomic challenges are present. CLINICAL TRIAL REGISTRATION: 2018-07-050BC, 2017-01-023ACF.

"U-shaped" mesoportal jump graft to manage portal vein thrombosis during liver transplantation: A case report.

INTRODUCTION: Once considered a contraindication to liver transplantation, portal vein thrombosis still represents a significant challenge to the liver transplant surgeon. Yerdel grade 3 thrombosis is usually managed by interposing a donor iliac vein jump graft between graft portal vein and distal superior mesenteric vein. Venous patch is normally placed in a retrogastric position to avoid its kinking. PRESENTATION OF CASE: We report a new technical variant of standard mesoportal jump graft, in which a U-shaped graft was obtained using iliac bifurcation. This technique was used to manage a case of grade 3 portal vein thrombosis in which portal vein was unsuitable due to severe pylephlebitis and pylorus dissection had to be abandoned due to inflammatory changes issue of chronic pancreatitis. The venous patch was of sufficient length and shape to bypass pancreatic head and first duodenum, avoiding the need for its retrogastric placement and pylorus dissection. DISCUSSION: This case is a further demonstration that technical approach to portal vein thrombosis must be tailored according to its extent and surgical scenario. In selected cases, use of a curved U-shaped jump graft may represent a valuable option. CONCLUSION: This technical option should be included among options for the management of portal vein thrombosis and be part of the armamentarium of liver transplant surgeon.

Reconstruction of the aorto-iliac segment in occlusive disease using the AFX unibody graft.

BACKGROUND: The endovascular era has evolved the treatment of aorto-iliac occlusive disease (AIOD). Many institutions now use minimally invasive techniques including kissing iliac stents and covered endovascular reconstruction of the aortic bifurcation. These negate the high morbidity of open surgical reconstruction but do not allow for a crossover approach to treat infra-inguinal disease. The AFX stent does both by anatomically reconstructing the bifurcation in AIOD despite being marketed for aneurysmal aortic disease. This large, single-centre case series assesses the outcomes of treatment of AIOD using the AFX stent. METHODS: Patients with AIOD who presented to our institution between September 2016 and August 2018 were considered for AFX stenting if kissing iliac stents extending into the aorta or aortobifemoral bypass was required. Patient, treatment and outcome data were recorded with a primary outcome of primary patency at 12 months. RESULTS: AFX stenting was performed in 29 patients, with an average age of 69 years, 52% (15/29) patients had critical limb ischaemia. Technical success occurred in 100% of patients with clinical success in 96% (28/29). There were no cases of 30 day and 3 (10%) cases of 12 month mortality, 2 (7%) major and 7 (24%) minor complications arose. Median length of stay was 3 days. Primary patency at 12 months was 100% (n = 24). CONCLUSION: AFX stenting is a safe with satisfactory early results for the treatment of AIOD. The minimally invasive technique and preservation of cross-over approach makes AFX stenting a considered option for the treatment of AIOD.

Analysis of non-Newtonian effects within an aorta-iliac bifurcation region.

The geometry of the arteries at or near arterial bifurcation influences the blood flow field, which is an important factor affecting arteriogenesis. The blood can act sometimes as a non-Newtonian fluid. However, many studies have argued that for large and medium arteries, the blood flow can be considered to be Newtonian. In this work a comprehensive investigation of non-Newtonian effects on the blood fluid dynamic behavior in an aorta-iliac bifurcation is presented. The aorta-iliac geometry is reconstructed with references to the values reported in Shah et al. (1978); the 3D geometrical model consists of three filleted cylinders of different diameters. Governing equations with the appropriate boundary conditions are solved with a finite-element code. Different rheological models are used for the blood flow through the lumen and detailed comparisons are presented for the aorta-iliac bifurcation. Results are presented in terms of the velocity profiles in the bifurcation zone and Wall Shear Stress (WSS) for different sides of the bifurcation both for male and female geometries, showing that the Newtonian fluid assumption can be made without any particular loss in terms of accuracy with respect to the other more complex rheological models.

Lower Aorto-Iliac Bifurcation Position and Incident Cardiovascular Disease: A Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: With increasing age, a downward shift of the aorto-iliac bifurcation relative to the lumbar spine occurs. A lower bifurcation position is an independent marker for adverse vascular aging and is associated with increased burden of cardiovascular disease (CVD) risk factors; however, the associations between lower bifurcation position and CVD events remain unknown. METHODS: Abdominal computed tomography scans were used to measure the aorto-iliac bifurcation distance (AIBD, distance from the aorto-iliac bifurcation to the L5/S1 disc space). Cox proportional hazard analysis was used to determine the independent hazard of a lower bifurcation position (smaller AIBD) for incident coronary heart disease (CHD, defined as myocardial infarction, resuscitated cardiac arrest, or sudden cardiac death), CVD (CHD plus stroke or stroke death), and all-cause mortality (ACM). RESULTS: In the 1,711 study participants (51% male), the mean AIBD was 26 ± 15 mm. After a median follow-up of 10 years, 63 (3.7%) developed CHD, 100 (5.8%) developed CVD, and 129 (7.5%) were deceased. Compared to the 4th quartile of AIBD (highest bifurcation position), participants in the 1st quartile (lowest bifurcation position) had increased risk for CHD (hazard ratio (HR) = 1.5, 95% confidence interval (CI): 0.8-3.0, P = 0.2), CVD (HR = 1.8, 95% CI: 0.9-2.7, P = 0.1), and ACM (HR = 2.2, 95% CI: 1.3-3.6, P = 0.01). After adjustments for CVD risk factors, the HR for ACM was no longer significant. CONCLUSION: Despite being an independent marker for adverse vascular changes in the aorta, a lower aorto-iliac bifurcation position was not independently associated with future CVD events. The opposing effects of atherosclerosis and stiffness in the aorta may, in part, explain our null findings.

Analysis of non-Newtonian effects on Low-Density Lipoprotein accumulation in an artery.

In this work, non-Newtonian effects on Low-Density Lipoprotein (LDL) transport across an artery are analyzed with a multi-layer model. Four rheological models (Carreau, Carreau-Yasuda, power-law and Newtonian) are used for the blood flow through the lumen. For the non-Newtonian cases, the arterial wall is modeled with a generalized momentum equation. Convection-diffusion equation is used for the LDL transport through the lumen, while Staverman-Kedem-Katchalsky, combined with porous media equations, are used for the LDL transport through the wall. Results are presented in terms of filtration velocity, Wall Shear Stresses (WSS) and concentration profiles. It is shown that non-Newtonian effects on mass transport are negligible for a healthy intramural pressure value. Non-Newtonian effects increase slightly with intramural pressure, but Newtonian assumption can still be considered reliable. Effects of arterial size are also analyzed, showing that Newtonian assumption can be considered valid for both medium and large arteries, in predicting LDL deposition. Finally, non-Newtonian effects are also analyzed for an aorta-common iliac bifurcation, showing that Newtonian assumption is valid for mass transport at low Reynolds numbers. At a high Reynolds number, it has been shown that a non-Newtonian fluid model can have more impact due to the presence of flow recirculation.

Investigation of the optimal collagen fibre orientation in human iliac arteries.

The distribution of collagen fibres plays a significant role in the mechanical behaviour of artery walls. Experimental data show that in most artery wall layers there are two (or more) in-plane symmetrically disposed families of fibres. However, a recent investigation revealed that some artery wall layers have only one preferred fibre direction, notably in the medial layer of human common iliac arteries. This paper aims to provide a possible explanation for this intriguing phenomenon. An invariant-based constitutive model is utilized to characterize the mechanical behaviour of tissues. We then use three different hypotheses to determine the 'optimal fibre angle' in an iliac artery model. All three hypotheses lead to the same result that the optimal fibre angle in the medial layer of the iliac artery is close to the circumferential direction. The axial pre-stretch, in particular, is found to play an essential role in determining the optimal fibre angle.

Percutaneous panvascular intervention in an unusual case of extensive atherosclerotic disease.

It is common to see patients with atherosclerotic coronary disease and peripheral arterial disease in routine clinical practice. One needs to have a comprehensive and integrated multi-speciality approach and panvascular revascularization in such patients. We report a 54-year-old diabetic hypertensive male with extensive atherosclerotic coronary and peripheral arterial disease, who presented with congestive heart failure, claudication of both lower limbs and mesenteric ischemia. He underwent successful percutaneous panvascular revascularization of coronary, renal, mesenteric, aorto-iliac and superficial femoral arteries. Long-term patency of all the stents was also documented.