Endovascular Reconstruction for Total Aorto–Iliac Occlusion

Objectives: To analyze outcomes following endovascular treatment of total occlusion of the infrarenal aorta and aorto–iliac bifurcation in a multicenter Italian registry. Methods: It is a multicenter, retrospective, observational cohort study. From January 2015 to December 2018, 1306 endovascular interventions for aorto–iliac occlusive disease were recorded in the vascular registry. For this analysis, only patients treated for total occlusion of the infrarenal aorta and aorto–iliac bifurcation were included. Early (<30 days) primary outcomes of interest were technical success and mortality. Late major outcomes were primary and secondary patency and freedom from conversion to open aortic surgery. Results: A total of 54 (4.1%) patients met the inclusion criteria. Total percutaneous revascularization was possible in 41 (75.9%) patients and hybrid (endo plus open) intervention in 13 (24.1%) patients. The kissing-stent-graft technique was used in 45 (83.3%) cases, covered endovascular reconstruction of the aortic bifurcation (CERAB) in 5 (9.2%), and a unibody endograft deployed in 4 (7.4%). Technical success was 98.1% (n = 53). There were no episodes of intraoperative or perioperative vessel rupture. Conversion to open surgery was not necessary, and there were no in-hospital deaths. The median patient follow-up time was 16 months (interquartrile range [IQR], 6-27). The estimated primary patency rate was 95.8% ± 0.03 (95% confidence interval [CI]: 85.5-98.9) at 1 year, 91.4% ± 0.05 (95% CI: 76.2-97.2) at 2 years, and 85 ± 0.08 (95% CI: 64.5-94.6) at 3 years. Cox regression analysis demonstrated that sex (hazard ratio [HR]: 0.96; 95% CI: 0.15-6.23, p = 0.963), extent of the occlusion (HR: 0.28; 95% CI: 0.05-1.46, p = 0.130), calcium score (HR: 1.88; 95% CI: 0.31-11.27, p = 0.490), or type of endovascular reconstruction (HR: 0.80; 95% CI: 0.13-5.15, p = 0.804) did not affect primary patency. Secondary patency was 95.5% ± 0.04 (95% CI: 78.4-99.2) at 3 years. No patients required late conversion to open surgical bypass. Conclusions: Endovascular reconstruction for total occlusion of the infrarenal aorta and aorto–iliac bifurcation was successful using a combination of percutaneous and hybrid revascularization techniques. Estimated patency rates at 3 years of follow-up are promising and are unaffected by the extent of occlusion or type of revascularization.

Numerical Study of the Unsteady Flow in Simplified and Realistic Iliac Bifurcation Models

Cardiovascular diseases are a major cause of death and disability worldwide and they are commonly associated with the occurrence of atherosclerotic plaque deposition in the vessel walls, a process denoted as atherosclerosis. This is a chronic and progressive inflammatory disease of large-/medium-sized blood vessels that affects blood flow profiles, with the abdominal aorta and its branches being one of the locations prone to the development of this pathology, due to their curvatures and bifurcations. In this regard, the effect of flow patterns was studied and compared for both a simplified three-dimensional model of aorta bifurcation on the iliac arteries and a realistic model of iliac bifurcation, which was constructed from a computational tomography medical image. The flow patterns were analyzed in terms of velocity and wall shear stress distribution, but a special focus was given to the size and location of the recirculation zone. The simulations were performed using the Computational Fluid Dynamics software, FLUENT, taking into account the cardiac cycle profile at the infrarenal aorta. The shear stress and the velocity distribution observed for both models indicated that higher shear stress occurred along the flow divider wall (inner wall) and low shear stress occurred along the outer walls. In addition, the results demonstrated that the wall shear stress profiles were deeply affected by the transient profile of the cardiac cycle, with the deceleration phase being the most critical phase to the occurrence of backflow.

Management of Subintimal Position of Kissing Stents using Re-entry Catheter with Cone Beam-Computed Tomography Image Overlaid onto Live Fluoroscopy

Background Several endovascular or surgical treatments have been proposed to treat total chronic occlusions of the iliac bifurcation. Nowadays, endovascular options are considered as a first choice because of the decreased per-operative morbi-mortality. Nevertheless, unexpected intraoperative events may occur, such as dissection or rupture of the iliac artery. We report a case of inadvertent bilateral false lumen kissing stents positioning, rescued with stents extensions guided with image fusion guidance. Case presentation A 60-year-old male patient referred to our Department because of a severe bilateral claudication, 8 months after an iliac kissing stent for common iliac arteries occlusion. A CT angiography (CTA) was performed, showing a bilateral dissection of the aorto-iliac bifurcation at the proximal part of the stents, which were placed into the false lumen whereas the distal part was into the true lumens (TL). Lower limb perfusion was maintained by inferior mesenteric and hypogastric arteries. As a CTA performed before the first endovascular intervention showed no dissection of the aortic bifurcation, the flaps were probably created during the previous interventions. An endovascular revision was planned. After a bilateral femoral access, the proximal part of the flap was pierced with a needle-based re-entry device, deployed under three-dimensional cone-beam CT image overlay with bi-planar fluoroscopy. The lumen patency was then restored with stents extensions up to the renal ostia. The final angiography showed stents patency. No complication occurred during the intervention. The patient was dismissed the day after, with good arterial femoral pulse and no further complications. An US color Doppler performed one month after the intervention showed satisfactory blood flow of both iliac and femoral arteries as well as a good flow in the lower limbs. Conclusions The integration of modern 3D image guidance and novel endovascular devices allows the management of adverse events with a minimally-invasive approach.

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.

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.

Comparison of Two Iliac Branch Devices and Their Midterm Performance in Maintaining Blood Flow to the Internal Iliac Artery

Purpose: To compare and contrast the midterm outcomes of the E-liac and Zenith (ZBIS) iliac branch devices (IBDs) for the preservation of the internal iliac artery (IIA) in aneurysms involving the iliac bifurcation. Materials and Methods: Between January 2014 and December 2018, 84 consecutive patients (median age 74 years; 76 men) were electively treated with the E-liac (n=44) or ZBIS (n=40) IBDs and were retrospectively analyzed to evaluate the technical success, patency, need for reintervention, and mortality associated with these devices. Results: Technical success was achieved in 95 of 99 implantations (95.9%) without any statistically significant difference between the groups (93.7% vs 98.0%, p=0.114). During the first 30 days, 3 occlusions in the ZBIS group and 1 in the E-liac group were identified. There was 1 perioperative death in the ZBIS group. The median follow-up was 37 months for the ZBIS group and 28 months for the E-liac group (p=0.657). Six patients from the ZBIS group and 7 from the E-liac group were lost to follow-up. Among the remaining, there were 2 further deaths recorded, 1 in each group. Four further reinterventions in the E-liac group and 2 in the ZBIS group were performed during follow-up. The Kaplan-Meier estimates of freedom from reintervention were 87.2% (95% CI 82.6% to 90.2%) for the ZBIS group and at 86.0% (95% CI 83.7% to 89.1%) for the E-liac group (p=0.563); the freedom from occlusion estimates were 89.7% (95% CI 85.8% to 94.5%) and 95.3% (95% CI 92% to 98.7%; p=0.317), respectively. Conclusion: The E-liac and the ZBIS IBDs showed equally high technical success, midterm patency, and low reintervention rates.

Variability in the size of the retroperitoneal oblique corridor: A magnetic resonance imaging-based analysis

Background: A minimally invasive approach to the L2-S1 disc spaces through a single, left-sided, retroperitoneal oblique corridor has been previously described. However, the size of this corridor varies, limiting access to the disc space in certain patients. Here, the authors retrospectively reviewed lumbar spine magnetic resonance imaging (MRI) in 300 patients to better define the size and variability of the retroperitoneal oblique corridor. Methods: Lumbar spine MRI from 300 patients was reviewed. The size of the retroperitoneal oblique corridor from L2-S1 was measured. It was defined as the (1) distance between the medial aspect of the aorta and the lateral aspect of the psoas muscle from L2-L5 and (2) the distance between the midpoint of the L5-S1 disc and the medial aspect of the nearest major vessel on the left at L5-S1. In addition, the rostral-caudal location of the iliac bifurcation was measured. Results: The size of the retroperitoneal oblique corridor at L2/3, L3/4, L4/5, and L5/S1 was, respectively, 17.3 ± 6.4 mm, 16.2 ± 6.3 mm, 14.8 ± 7.8 cm, and 13.0 ± 8.3 mm. The incidence of corridor size <1 cm at L2/3, L3/4, L4/5, and L5/S1 was 10.3%, 16.0%, 30.0%, and 39.3%, respectively. The iliac bifurcation was most commonly found behind the L4 vertebral body (n = 158, 52.67%) followed by the L4/5 disc space (n = 74, 24.67%). Conclusion: The size of the retroperitoneal oblique corridor diminishes in a rostral-caudal direction, often limiting access to the L4/5 and L5/S1 disc spaces.