Feasibility of patchless proximal profundoplasty and common femoral endarterectomy.

BACKGROUND: Typical repair of common femoral artery (CFA) occlusive disease involves surgical endarterectomy followed by patch closure; however, prosthetic materials may become infected. In addition, in our institution, we have experienced an increased incidence of severe patch-related restenosis. We describe a technique for CFA endarterectomy and patchless proximal profundoplasty, and evaluate its feasibility. METHODS: We performed a single-centre retrospective cohort study of patients who, between July 1, 2020, and June 30, 2021, underwent a procedure that consisted of transection of the superficial femoral artery (SFA) off the femoral bifurcation in a bevelled manner, eversion endarterectomy of the SFA, remote-type endarterectomy of the CFA, direct visualization of the end point in the profunda femoris artery (PFA) with a longitudinal arteriotomy extension if needed and reimplantation of the SFA "hood" as a patch. We collected clinical information and outcomes from the patients' charts. RESULTS: Ten patients who underwent a patchless profundoplasty procedure during the study period were identified. Indications for repair included tissue loss (3 patients), rest pain (2 patients), claudication (3 patients) and establishing access for other procedures (2 patients). Profunda femoris artery arteriotomy extensions were used in 5 cases. Six cases included simultaneous iliac or infrainguinal revascularization. All cases were technically successful. There was 1 intraoperative complication of remote tibial balloon angioplasty tear. The mean follow-up time was 199 (range 29-381) days. There were no surgical site infections. All patients were asymptomatic, with patent CFAs, at last follow-up. There was 1 case of surgical site restenosis and 1 reintervention for remote stenosis. The average increase in ankle and toe brachial indices was 44% and 75%, respectively. One patient was readmitted for gastrointestinal bleeding. One patient died from an acute myocardial infarction, on postoperative day 34. CONCLUSION: The patchless profundoplasty technique is feasible and results in autologous anatomic repair of CFA disease without the need for vein, and allows direct visualization and tacking sutures of the proximal PFA. This technique may replace the ubiquitous vascular procedure of patch arterioplasty of the CFA, depending on the anatomic configuration.

Comparison of Qualitative and Quantitative Assessments of Iliac Artery Tortuosity and Calcification.

INTRODUCTION: During endovascular aneurysm repair, the iliac artery typically serves as a conduit for device delivery. The degree of tortuosity and calcification in the iliac artery ultimately determines whether the device can successfully traverse the vessel. These 2 parameters can be assessed using qualitative approaches or calculated using quantitative methods based on the Society for Vascular Surgery (SVS) reporting standards. The objective of this study was to determine whether qualitative methods are sufficient to accurately assess iliac artery tortuosity and calcification by calculating interobserver variability and comparing them to the SVS Reporting Standards. METHODS: Three vascular surgeons reviewed preoperative computed tomography scans for 50 patients who underwent fenestrated endovascular aneurysm repair and qualitatively assessed left and right iliac artery tortuosity and calcification. Iliac artery geometries were segmented from these image sets. Tortuosity index and calcification length ratio were calculated and categorized based on the SVS Reporting Standards. RESULTS: Interobserver variability was calculated for the qualitative assessments using interclass correlation coefficients. For tortuosity index, among the 3 observers, good agreement was found for the left iliac artery and fair agreement was found for the right. For calcification length ratio, excellent agreement was found for both iliac arteries. When compared to the quantitative assessment, the qualitative assessments underpredicted tortuosity in 2.3% of cases, matched the quantitative values in 16.7% of cases, and overpredicted tortuosity in 81.0% of cases. The qualitative assessments underpredicted calcification in 46.3% of cases, matched the quantitative values in 49.3% of cases, and overpredicted calcification in 4.3% of cases. CONCLUSION: Qualitative assessment of iliac artery tortuosity showed fair-to-good interobserver agreement and poor agreement to SVS Reporting Standards. Qualitative assessment of iliac artery calcification showed excellent interobserver agreement and fair agreement to SVS Reporting Standards. These trends should be considered when qualitative reporting methodologies are used.

Analysis of Iliac Artery Geometric Properties in Fenestrated Aortic Stent Graft Rotation.

INTRODUCTION: A complication of fenestrated endovascular aneurysm repair is the potential for stent graft rotation during deployment causing fenestration misalignment and branch artery occlusion. The objective of this study is to demonstrate that this rotation is caused by a buildup of rotational energy as the device is delivered through the iliac arteries and to quantify iliac artery geometric properties associated with device rotation. METHODS: A retrospective clinical study was undertaken in which iliac artery geometric properties were assessed from preoperative imaging for 42 cases divided into 2 groups: 27 in the nonrotation group and 15 in the rotation group. Preoperative computed tomography scans were segmented, and the iliac artery centerlines were determined. Iliac artery tortuosity, curvature, torsion, and diameter were calculated from the centerline and the segmented vessel geometry. RESULTS: The total iliac artery net torsion was found to be higher in the rotation group compared to the nonrotation group (23.5 ± 14.7 vs 14.6 ± 12.8 mm-1; P = .05). No statistically significant differences were found for the mean values of tortuosity, curvature, torsion, or diameter between the 2 groups. CONCLUSION: Stent graft rotation occurred in 36% of the cases considered in this study. Cases with high iliac artery total net torsion were found to be more likely to have stent graft rotation upon deployment. This retrospective study provides a framework for prospectively studying the influence of iliac artery geometric properties on fenestrated stent graft rotation.

Toothpick-induced aortoenteric fistula presenting as sepsis.

Aortoenteric fistulas (AEF) are a rare but life-threatening cause of gastrointestinal (GI) bleeding. We present the case of a primary AEF caused by ingestion of a toothpick by a 47-year-old male. This is the 10th known case in the literature in which a foreign body was found to be the cause of a communication between the aorta and the GI tract. Most foreign objects have been sewing needles; this is the first known case of a toothpick penetration. The patient presented to our institution with polymicrobial sepsis and bilateral pulmonary septic emboli. The patient was successfully treated but required multiple interventions and a prolonged intensive care unit admission.

'In-stock' fenestrated stent graft for the urgent repair of an abdominal aortic aneurysm.

Endovascular aneurysm repair (EVAR) is a minimally invasive method for the treatment of abdominal aortic aneurysms; however, the implementation of this technique is often limited by the aortic pathology, especially in the urgent or emergent setting. An 82-year-old male with a 7.3 cm symptomatic juxtarenal aneurysm presented at our centre for assessment. He was diagnosed as a high-risk candidate for open repair and therefore, not suitable for a conventional EVAR. Fortunately, a custom two-vessel fenestrated stent graft, which was originally constructed for another patient, was available. This device was implanted with no complications and all branches remain unobstructed; clear of aneurysms at 1 year. We present the use of 'in-stock' fenestrated grafts as a potential option to be considered in the urgent or emergent repair of abdominal aortic aneurysms.

Increasing angulation decreases measured aortic stent graft pullout forces.

OBJECTIVE: Experimentally measured pullout forces for stent grafts (SGs) are used in clinical discussions and as reference values in bench studies and computer simulations. Previous values of these forces are available from studies in which the SG was pulled out in the straight caudal direction. However, clinical and numerical studies have suggested that displacement forces acting on SGs are directed more anteriorly. The objective of this study was to measure pullout forces as a function of angulation and to test the hypothesis that pullout forces decrease with increasing angulation. METHODS: Six different SGs (Bolton Treovance, Cook Zenith Flex, Cook Zenith LP, Medtronic Endurant, Medtronic Talent, and Vascutek Anaconda) were deployed in fresh bovine aortas, then pulled out by an electronic motor at 1 mm/s, while tension force was measured continuously with a digital load cell. The SG off-axis angulation was changed from 0 to 90 degrees in increments of 10 degrees. The test system was submerged in a custom-built temperature-controlled saline bath at 37°C. At least three tests were performed for each device at each angle (with the exception of the Cook Zenith Flex, which experienced plastic deformation of its barbs after a single test per device). Each aortic specimen was used only once and then discarded. Hand-sutured graft anastomoses were also tested at 0 degrees to provide a reference value. RESULTS: A total of 374 pullout tests were performed for the SGs and anastomoses. Sixty-four tests were excluded because of failure of the aorta or apparatus before device pullout. The remaining 310 tests showed pullout forces that demonstrated a decrease in the average pullout force for all six devices from 0 to 90 degrees (Bolton Treovance from 39.3 N to 23.9 N; Cook Zenith Flex from 59.8 N to 48.9 N; Cook Zenith LP from 50.3 N to 41.8 N; Medtronic Endurant from 29.9 N to 25.8 N; Medtronic Talent from 6.0 N to 5.5 N; and Vascutek Anaconda from 37.0 N to 30.3 N). For reference, the mean pullout force for the hand-sutured anastomoses was 63 N. CONCLUSIONS: This study reports for the first time the change in pullout force with angulation, showing a general pullout force decrease with increasing angle. With a larger number of samples than in previous studies, our results provide updated benchmark data that can be used for clinical discussions, computational and experimental studies, and future device design.

Effects of Pulsatile Fatigue on In Situ Antegrade Fenestrated Polyester Stent Grafts Deployed in a Patient-Specific Phantom Model of Juxtarenal Aortic Aneurysm.

PURPOSE: To evaluate the effects of in situ fenestration on the fabric of stent grafts deployed in a patient-specific phantom of a juxtarenal abdominal aortic aneurysm. MATERIALS AND METHODS: Four patient-specific juxtarenal abdominal aortic aneurysm polyurethane models were created, and bifurcated Zenith (Cook, Inc, Bloomington, Indiana) and Endurant (Medtronic, Minneapolis, Minneapolis) endografts were deployed into the models, covering the renal arteries. Antegrade in situ fenestration was carried out with radiofrequency puncture followed by balloon dilation with either conventional or cutting balloons. Renal covered stents were deployed and flared. Specimens were mounted onto an accelerated fatigue tester for 40M cycles (1 patient life-year), and evaluated with microscopy, caliper measurements, and fabric counts. RESULTS: Cutting balloons resulted in more fabric fraying. None of the fenestrations grew beyond the targeted 6-mm diameter despite accelerated fatigue. Fluoroscopic images demonstrated a very prominent waist of the renal fenestration in the Cook device when a conventional balloon was used compared with a cutting balloon. The average fenestration diameter for the Cook device was only 3.1 mm with the conventional balloon compared with 4.8 mm with the cutting balloon. The average fenestration diameter for the Medtronic device was 3.8 mm with the conventional balloon compared with 5.1 mm with the cutting balloon. The fabric counts suggested crowding of yarns around the fenestrations with conventional balloons but less with cutting balloons. CONCLUSIONS: This experimental work suggests that the size of in situ renal fenestrations does not expand beyond the target diameter despite cyclic fatigue. Although the small number of devices tested and selected aortorenal anatomy in this study may limit conclusions, textile analysis suggests that cutting balloons should be used for the Cook Zenith device, whereas conventional balloons should be used for the Medtronic Endurant device when performing in situ fenestration.

Radiofrequency in situ fenestration for aortic arch vessels during thoracic endovascular repair.

PURPOSE: To report the first clinical application of a novel technique using radiofrequency puncture to create retrograde in situ fenestrations during thoracic endovascular aortic repair (TEVAR). METHODS: Between June 2011 and December 2013, 40 TEVAR procedures were performed in our facility, including 10 cases in which in situ fenestration was planned. Two thoracic stent-graft models were deployed: the Valiant (n=5) and the Zenith TX2 (n=5). A 0.035-inch PowerWire radiofrequency guidewire delivered from a brachial approach was used to fenestrate the grafts covering a left subclavian artery (LSA) in 9 cases and a left common carotid artery in one. The fenestrations were serially dilated to 6 mm, and self-expanding Advanta V12 covered stents were positioned in the target arteries. RESULTS: Technical success was achieved in 6 of the 10 planned cases. Of the remaining 4 cases, stent-grafts were deployed in zone 3 in 2 cases (one received a chimney to the LSA). Another stent-graft was deployed in zone 2 without endoleak after fenestration was abandoned (the LSA had good filling via the vertebral artery). In the last case, the fenestration was unsuccessful in double-layered (proximal extension overlap) stent-grafts; a carotid-axillary bypass was required. There were no fenestration-related complications, but overall surgical complications included a case of paraparesis that resolved following spinal drainage and a death from a preexisting aortoesophageal fistula. There were no postoperative strokes. All fenestrations remained patent, and there were no endoleaks at a mean 12-month follow-up (range 1-33). CONCLUSION: Radiofrequency puncture is a viable alternative to needle or laser punctures for in situ fenestration during TEVAR. Early clinical results suggest technical feasibility and acceptable early outcomes.

Thoracic aortic frontier: review of current applications and directions of thoracic endovascular aortic repair (TEVAR).

Thoracic endovascular aortic repair, a minimally invasive technique is replacing the maximally invasive gold standard of thoracotomy and replacement of the descending thoracic aorta. With experience, indications have expanded to encroach on the arch and even ascending aorta. This review highlights the current state of technology, discusses controversies, and takes the perspective of a forward-thinking review to describe novel, innovative techniques that might make the entire thoracic aorta amenable to minimally invasive repair.

Computational fluid dynamics evaluation of the cross-limb stent graft configuration for endovascular aneurysm repair.

The technique of crossing the limbs of bifurcated modular stent grafts for endovascular aneurysm repair (EVAR) is often employed in the face of splayed aortic bifurcations to facilitate cannulation and prevent device kinking. However, little has been reported about the implications of cross-limb EVAR, especially in comparison to conventional EVAR. Previous computational fluid dynamics studies of conventional EVAR grafts have mostly utilized simplified planar stent graft geometries. We herein examined the differences between conventional and cross-limb EVAR by comparing their hemodynamic flow fields (i.e., in the "direct" and "cross" configurations, respectively). We also added a "planar" configuration, which is commonly found in the literature, to identify how well this configuration compares to out-of-plane stent graft configurations from a hemodynamic perspective. A representative patient's cross-limb stent graft geometry was segmented using computed tomography imaging in Mimics software. The cross-limb graft geometry was used to build its direct and planar counterparts in SolidWorks. Physiologic velocity and mass flow boundary conditions and blood properties were implemented for steady-state and pulsatile transient simulations in ANSYS CFX. Displacement forces, wall shear stress (WSS), and oscillatory shear index (OSI) were all comparable between the direct and cross configurations, whereas the planar geometry yielded very different predictions of hemodynamics compared to the out-of-plane stent graft configurations, particularly for displacement forces. This single-patient study suggests that the short-term hemodynamics involved in crossing the limbs is as safe as conventional EVAR. Higher helicity and improved WSS distribution of the cross-limb configuration suggest improved flow-related thrombosis resistance in the short term. However, there may be long-term fatigue implications to stent graft use in the cross configuration when compared to the direct configuration.

Bridging stent-graft pullout force analysis.

PURPOSE: To assess the pullout force (POF) of bridging stent-grafts used in thoracoabdominal stent-grafts and iliac bifurcated grafts. METHODS: In an experimental setup, the POFs of Viabahn or Fluency with or without a Zilver stent were measured when deployed into the renal and celiac branches of a Zenith thoracoabdominal cuff-bearing branched stent-graft. The POFs of the Atrium i-Cast, Viabahn, Fluency, and Fluency+Zilver were measured when deployed into an iliac bifurcated graft with a short side-branch for the internal iliac artery. At least 10 trials were performed for each stent in air at room temperature. RESULTS: The median POF (IQR; absolute range) required to dislodge each bridging stent-graft from the 6-mm renal branch was 1.89 N (0.47 N; 1.65-2.5) for the 7-mm Viabahn, 1.17 N (0.39 N; 0.68-1.57 N) for the 7-mm Fluency, and 2.08 N (0.49 N; 1.59-2.62 N) for the 7-mm Fluency with a supporting 8-mm Zilver stent (p<0.001). For the 8-mm celiac branch, the POFs were 2.79 N (0.82 N; 2.31-4.16 N), 1.74 N (0.18 N; 1.51-1.91 N), and 2.73 N (0.94 N; 1.9-3.61 N) for the 9-mm Viabahn, 9-mm Fluency, and 9-mm Fluency with a 10-mm Zilver stent, respectively (p<0.001). For the 8-mm internal iliac branch, the POFs were 3.53 N (0.85 N; 2.55-4.72 N) for the 9-mm i-Cast, 3.82 N (0.41 N; 3.29-4.45 N) for the 9-mm Viabahn, 2.32 N (0.23 N; 1.63-2.64 N) for the 9-mm Fluency, and 2.61 N (0.71 N; 1.65-3.63 N) for the 9-mm Fluency with a 10-mm Zilver stent (p<0.001). CONCLUSION: There is a small but significant difference in pullout forces among various bridging stent-grafts. As pullout forces may be one factor contributing to type III endoleaks in complex endovascular repairs involving fenestrated and branched stent-grafts, further study is warranted to compare these grafts clinically to determine if they perform differently. According to this study, the theoretical advantages associated with the Viabahn stent-graft make it a strong choice for minimizing branch dislocations.

Radiofrequency perforation system for in vivo antegrade fenestration of aortic stent-grafts.

PURPOSE: To evaluate the ability to create in vivo antegrade fenestrations (IVAF) using a radiofrequency probe in juxtarenal aortic stent-grafts to preserve the patency of renal arteries. METHODS: Modified stent-grafts with an unsupported fenestration area were deployed in the juxtarenal aorta of 2 25-kg dogs. Prior to deployment, both renal arteries were marked with detachable coils that were later removed (dog 1) or with hydrophilic catheters (dog 2). After deployment, a radiofrequency probe was used to perforate the graft. If puncture was successful, attempts were made to pass guidewires into the renal arteries for balloon dilation and stenting of the graft perforation. Doppler ultrasound scans of the renal arteries were taken after 1 week. Doppler ultrasound and angiography were repeated prior to autopsy and macroscopic analysis at 1 month. RESULTS: Fenestration was attempted in 3 renal arteries (1 in dog 1 and 2 in dog 2). It was successful in 2 renal arteries but required 6 attempts in dog 1 and 3 in dog 2. The failed case was related to the position of a stent-graft strut close to the fenestration area. One stent thrombosis was seen during follow-up, while the other fenestrated artery remained patent. No stent fracture was encountered during follow-up. CONCLUSION: This radiofrequency device allowed successful fenestration but was difficult to control. Technical improvements are required to improve clinical success and patency.

In vivo antegrade fenestration of abdominal aortic stent-grafts.

PURPOSE: To examine in a canine model the feasibility of antegrade fenestration of abdominal aortic stent-grafts to preserve the patency of the renal arteries. METHODS: Two large dogs underwent antegrade fenestration of stent-grafts in the perirenal aorta. Before fenestration, bare stents were inserted in both renal arteries as fluoroscopic landmarks. A 12-mm iliac extension served as the canine aortic endograft. The first procedure was done under ultrasound and fluoroscopic guidance, using an intravascular ultrasound (IVUS) probe inserted in the vena cava and a Pioneer IVUS catheter. The second was performed exclusively under fluoroscopic guidance with a Brockenbrough needle. Angiograms and duplex ultrasound were planned for 1 month, after which the dogs would be sacrificed for autopsy. The explanted endograft was subjected to biomaterials analysis, with a focus on fabric tear. RESULTS: Perforation of the aortic graft and catheterization of the renal arteries with a floppy guidewire were possible in both animals. In dog 1, aortic graft dilation and subsequent fenestration were not possible, and the experiment was terminated. However, the procedure was successful in both renal arteries of dog 2. At 1-month follow-up in this dog, both renal arteries were patent. Stent fractures were observed bilaterally. There was no extension of the damage to the fabric beyond the area of fenestration. CONCLUSION: In vivo antegrade fenestration of aortic endografts is technically feasible. However, improvements in technique, instrumentation, and materials are required to make it a reliable and reproducible way of allowing stent-graft vascularization of aortic side branches.

Early outcomes after elective and emergent endovascular repair of the thoracic aorta.

BACKGROUND: Endovascular treatment of thoracic aortic pathology has emerged as a viable alternative to open surgical repair in both the elective and emergent settings. The aim of this study was to evaluate preoperative work-up, intra-operative strategy, and outcomes of endovascular stent-grafting of the thoracic aorta in patients undergoing elective repair and those undergoing emergent repair. METHODS: All patient information was obtained by a retrospective review of an established clinical database for all endovascular thoracic stent-graft cases. From October 1999 to August 2005, 70 patients were treated with endovascular stent-grafts for lesions of the thoracic aorta. Thirty-five patients had an elective endovascular procedure, and 35 patients had an emergent procedure. RESULTS: Thirty-five patients in the endovascular (EL) group were treated for aneurysm (n = 34) and type B dissection (n = 1). Thirty-five patients in the emergent (EM) group were treated for aneurysm (n = 10), intramural hematoma (n = 10), type B dissection (n = 7), traumatic rupture (n = 7), and aortoesophageal fistula (n = 1). Preoperative angiography was performed in 94.3% (33/35) of EL patients but in only 45.7% (16/35) EM patients (P < .005). The EM procedures had significantly shorter operative times, used lower contrast volumes, used fewer stent-graft components (mode 2, range 1 to 5 vs mode 1, range 1 to 3; P = .02), and spinal cerebrospinal fluid drains were used significantly less often (82.9% vs 57.1%, P = .04). Both groups had similar 30-day morbidity, mortality (0/35 EL vs 1/35 [2.9%] EM, P = .99), postoperative endoleak (9/35 [25.7%] EL vs 7/35 [20.0%] EM, P = .78), endovascular failure (3/35 [8.6%] EL vs 5/35 [14.3%] EM, P = .71), and patient survival. CONCLUSION: There are significant differences in the underlying pathology, preoperative evaluation, and operative course between elective and emergency treatment endovascular procedures for lesions of the thoracic aorta. Endovascular repair of thoracic aortic lesions can be accomplished with low perioperative mortality and morbidity rates, as well as acceptable endoleak and endovascular failure rates for both elective and emergency procedures.

Branched endovascular stent-graft for suprarenal aortic aneurysm: the future of aortic stent-grafting?

The use of a branched endovascular stent-graft to repair an aneurysm of the visceral aorta is described. The evolving role of branched endovascular stent-grafts in the management of aortic aneurysms is discussed, and the literature reviewed.

The proximal landing zone in endovascular repair of the thoracic aorta.

In this study we evaluated the relationship between the site of the proximal landing zone during endovascular repair of thoracic aortic pathology and treatment outcomes. We reviewed all cases of endovascular repair of thoracic aortic lesions at our institution in the past 42 months. Thirty-seven Talent thoracic endografts were used to treat 20 thoracic aneurysms, 8 intramural hematomas, 6 aortic dissections, and 3 post-traumatic aneurysms. The proximal edge of the covered endograft was situated proximal to the left common carotid artery (zone 1) in 3 patients, between the left common carotid and subclavian arteries (zone 2) in 4 patients, <2 cm distal to the left subclavian artery (zone 3) in 9 patients, and >2 cm distal to the left subclavian (zone 4) in 21 patients. Five patients had extraanatomic bypass to revascularize one or more covered aortic branches. For zones 1, 2, 3, and 4 the endoleak rates were 100%, 0%, 11%, and 0%, respectively; the secondary procedure rates were 33%, 0%, 11%, and 5% respectively; and the treatment failure rates were 67%, 0%, 11%, and 0%, respectively (p < 0.05, for endoleak rates, using Fisher's exact test to compare zone 1 to zones 2, 3, and 4 individually, and as a group). All three endovascular failures were due to proximal type 1 endoleaks. In conclusion, despite the use of great-vessel ligation and extraanatomic bypass to extend the proximal landing zone into the aortic arch, we have been unable to reliably exclude thoracic aortic pathology through use of endografts when the proximal landing zone is proximal to the left common carotid artery.