Unintended Exchange of Target Vessels for Celiac Trunk and Superior Mesenteric Artery Branches in Complex Endovascular Aortic Repair.

PURPOSE: The treatment of thoracoabdominal aortic aneurysms (TAAAs) using branched endovascular aortic repair (BEVAR) is safe and effective. During deployment, the superior mesenteric artery (SMA) branch can unintentionally open into the celiac trunk (CT) ostium and switched catheterization of the SMA from the CT branch and the CT from the SMA branch can be used as an alternative technique in these cases. This study aimed to investigate the outcome of exchanging the intended target vessels (TVs) for the CT and SMA branches during BEVAR. MATERIALS AND METHODS: A single-center retrospective analysis of patients with TAAAs who underwent BEVAR, using off-the-shelf or custom-made devices (CMDs), with an unintended exchange of TVs for the CT and SMA branches was performed. RESULTS: Between 2014 and 2023, 397 patients were treated with BEVAR for TAAA. Eighteen (4.5%) of those patients were treated with an exchange of TVs for the CT and SMA branches. T-branch was used in 9 cases (50%) and the remaining patients were treated with CMDs. Twelve patients were treated electively, 3 were symptomatic and 3 presented with rupture. Of 36 mesenteric TVs in those 18 patients, 34 (94%) were catheterized successfully, including all 18 SMAs and 16 of the 18 CTs. No branch stenosis or occlusion of the switched mesenteric TVs was detected during follow-up. During 30-day follow-up, 3 patients died and during a median follow-up of 3 (interquartile range [IQR]: 1-15) months 3 more patients died. None of the deaths or the 2 unintended reinterventions was induced by the mesenteric TV exchange. The median hospital stay was 14 (IQR: 9-22) days with a median of 4 (IQR: 2-11) days at the intensive care unit. CONCLUSION: The exchange of the mesenteric TVs for the CT and SMA branches during BEVAR with off-the-shelf and CMD endografts is feasible with good TV patency and freedom from TV-related reinterventions. This alternative technique should be considered in selected cases when direct catheterization via the intended branch is deemed more time-consuming or not feasible. CLINICAL IMPACT: This is the first description of using an exchange of target vessels for the celiac trunk and the superior mesenteric artery branches in patients with thoracoabdominal aortic aneurysms undergoing BEVAR, using off-the-shelf or custom-made devices. The high success rate as well as the good clinical results without any branch stenosis or occlusion during follow-up highlight the feasibility of this alternative technique. It could help in challenging cases when catheterization of the intended target vessels is not possible or too time consuming, resulting in higher success rates of BEVAR and better clinical results.

Modified upside-down technique with Gore tapered iliac limbs for isolated iliac artery aneurysms.

PURPOSE: To describe the off-label use of tapered iliac limbs for the treatment of isolated iliac aneurysms with proximal landing zone significantly larger than distal landing zone. TECHNIQUE: Inversion of a Gore Excluder tapered leg (W. L. Gore & Associates Inc, Flagstaff, Arizona) with a modified upside-down technique is described. The endoprosthesis, with the olive at the tip of the releasing system previously cut, is inserted in a tip-to-tip fashion into a 15 Fr introducer sheath. The graft is released inside the introducer. An 18 Fr introducer sheath is advanced up to the proximal sealing zone. Following the removal of the 18 Fr dilator, the 15 Fr introducer with the pre-released graft is inserted co-axially into the 18 Fr introducer. A pre-cut 15 Fr dilator is brought up to the endograft and used as a pusher. A pull-back maneuver of the co-axial system, countertractioning with the dilator maintained in position, allows the delivery of the endograft. CONCLUSION: This technique might offer a feasible option in case of endovascular exclusion of isolated iliac artery aneurysms with significant landing zone diameter mismatch. Extracorporeal inversion is time-saving and could be safer in terms of graft damage and infection.

Reverse Cheese-Wire Septotomy to Create a Distal Landing Zone for Thoracic Endovascular Aortic Repair.

PURPOSE: The objective of this study is to describe a novel method for creating a distal landing zone for thoracic endovascular aortic repair (TEVAR) in chronic aortic dissection. The technique is described in a patient with prior total arch and descending aortic replacement, with false lumen expansion. TECHNIQUE: A cheese-wire endovascular septotomy was desired to create a single lumen above the celiac axis. To avoid dividing the septum caudally across the visceral segment, we performed a modified septotomy in a cephalad direction. Stiff wires were passed into the prior surgical graft, through true lumen on the right and false lumen on the left. An additional wire was passed across an existing fenestration at the level of the celiac axis, and snared and externalized. 7F Ansel sheaths were advanced and positioned tip-to-tip at the fenestration. Using the stiff wires as tracks, the through-wire was pushed cephalad to endovascularly cut the septum. Angiogram demonstrated successful septotomy, and TEVAR was performed to just above the celiac with successful aneurysm exclusion and no endoleak or retrograde false lumen perfusion. Follow-up computed tomography angiogram (CTA) showed continued exclusion without false lumen perfusion. CONCLUSIONS: This novel modification in a reverse direction provides an alternative method for endovascular septotomy, when traditional septotomy may threaten the visceral vessels.

Giant Inferior Mesenteric Vein Aneurysm Secondary to Iatrogenic Inferior Mesenteric Arteriovenous Fistula.

PURPOSE: Visceral venous aneurysms are rare, especially in the inferior mesenteric vein (IMV). We report a giant IMV aneurysm secondary to an iatrogenic arteriovenous fistula (AVF). CASE REPORT: A woman presented with an incidental finding of a 7 cm large IMV aneurysm and an inferior mesenteric arteriovenous shunt. The patient underwent successful endovascular occlusion of the shunt to avoid aneurysm rupture and portal hypertension. CONCLUSION: Embolization is a possible treatment strategy for mesenteric venous aneurysms with an AVF. CLINICAL IMPACT: We describe an unusual mesenteric AV-shunt from a surgical crush injury that caused a giant venous mesenteric aneurysm and offer technical aspects on minimally invasive endovascular treatment.

Removal of Partially Deployed Supera Stents: Case-Based Review and Technical Considerations.

PURPOSE: Maldeployment of the Supera stent system can result in primary technical failure, inferior primary patency, and poorer patient outcomes. The purpose of this article is to present a case series illustrating the conditions required to perform optimal stent deployment, and if necessary, undertake successful stent removal following maldeployment. TECHNIQUE: Two key failures of effective Supera deployment are elongation and invagination. Several technical factors should be considered to reduce the risk of maldeployment: aggressive target vessel predilation, the use of multiple fluoroscopic views, slow deployment with controlled forward pressure applied on the delivery device, "sandwich packing" of the stent above and below target lesions, and the "pulling back" of invagination. To successfully retrieve a partially deployed stent, 3 factors should be considered: the percentage of the stent already deployed, the distance from the distal tip of the introducing sheath to the proximal extent of the deployed stent, and the severity of proximal vessel disease. The higher these factors, the greater the risk of stent detachment and failed retrieval. CONCLUSION: In this series of 6 cases of maldeployment, the removal of a partially deployed Supera stent appeared to be feasible and safe, with success dependent on selected technical and anatomical considerations.

Performance of the Gore VBX Balloon Expandable Endoprosthesis as Bridging Stent-Graft in Branched Endovascular Aortic Repair for Thoracoabdominal Aneurysms.

PURPOSE: Bridging stent stability is crucial for efficacy and safety of branched aortic endovascular repair (bEVAR) of thoracoabdominal aortic aneurysms (TAAAs). In this study, we assess the performance of the new Viabahn Balloon-Expandable endoprosthesis (VBX) in bEVAR. Based on our learning curve we give recommendations for a safe and effective use of the device. MATERIALS AND METHODS: We prospectively collected the data of patients with TAAAs undergoing bEVAR between December 2017 and December 2019. All patients with implantation of at least 1 VBX stent-graft as bridging stent were included in our single-center analysis. Demographic, comorbidity, and computed tomography angiography (CTA) data of 112 patients were retrospectively evaluated. Primary endpoint was a composite of branch-related technical success and freedom from target vessel instability. Secondary endpoints were clinical and ongoing clinical success. RESULTS: Primary endpoint: technical success was achieved in all patients (100%) with a freedom from target vessel instability of 96.3% after a median follow-up of 18 months. Overall mortality was 13.4% (n=15) and 13 patients underwent secondary interventions, 12 of them are still alive and 1 suffered from aneurysm sac expansion, consequently an ongoing clinical success of 75.9% was reached. After modification of the implantation technique during the course of the study by selecting longer stent lengths after accurate estimation of vessel curvature and expected adaptation of the flexible endoskeleton to the specific anatomical conditions, no type Ic endoleaks were observed in the last 70 cases. CONCLUSIONS: The VBX stent-graft can be safely used as bridging stent for branched thoracoabdominal repair. However, learning curve should be considered to avoid type Ic endoleak and edge stenosis. Based on this experience longer landing zones and 2-step deployment of VBX are useful for successful bridging also of challenging target vessels.

Preoperative Planning for EndoAnchor Use During Thoracic Endovascular Aortic Repair in the Distal Aortic Arch.

PURPOSE: To describe steps related to intraoperative C-arm orientations that can be taken during preoperative planning of thoracic stent-graft repair to facilitate the deployment of EndoAnchors in the distal aortic arch. TECHNIQUE: Previous experience from transcatheter aortic valve implantation (TAVI) may be helpful in addressing issues with C-arm orientation. In TAVI, preoperative computed tomography (CT) images are routinely obtained to generate a patient-specific curve that represents a virtually complete rotation of the C-arm perpendicular to the annulus. The curve clearly demonstrates that each adjustment in cranial or caudal view needs parallax correction in the left or right anterior oblique direction to remain perpendicular, and vice versa. This experience can be translated to the preoperative planning of EndoAnchor use in the aortic arch. By placing markers along the circumference of the proximal landing zone of the preoperative CT scan, the required C-arm orientations can be determined for each marker. CONCLUSION: Determining the optimal C-arm orientation during preoperative planning will facilitate successful EndoAnchor deployment and may contribute to improved durability of endovascular repair in hostile necks in the aortic arch.

Endovascular aortic repair with the Gore Excluder Conformable endograft in severe neck angulation: Preliminary experience and technical aspects.

OBJECTIVES: Endovascular procedures are now the standard of care for endovascular aortic aneurysm repair but treatment of hostile proximal neck anatomy is still challenging. New endografts were brought to the market specifically designed to accommodate severe neck angulation. Authors describe a preliminary experience and early results using the Gore Excluder Conformable endograft (W. L. Gore & Associates, Flagstaff, Ariz) and its active control system in severe neck angulation with a standardized technical approach to achieve precise deployment in this hostile anatomy. METHODS: From June 2019 to May 2020, five patients with abdominal aortic aneurysm and severe neck angulation (≥70°) were treated with the Gore Excluder Conformable endograft at two different centers. Deployment of this endograft in this kind of anatomy should be aggressive starting over the level of renal arteries due to risk of distal migration downward on the external curvature and difficulty in upward repositioning. Authors suggested a standard technique with a routine through-and-through axillary-femoral approach, using a floppy guidewire together with preventive cannulation of the lower renal artery if a short neck (<15 mm) is associated. RESULTS: Endovascular aortic procedures were successfully completed in all patients. Final deployment of the stent graft using our standardized technical approach was extremely precise in all cases even if redeployment of the graft was necessary in all cases. No other secondary procedures were needed. At 30 days, no type IA endoleak was recorded and no aneurysm-related secondary procedures were performed. Median follow-up for this group of patients was 5.2 months (range 1-11). Early results revealed no type IA endoleak and no migration at Ct angiogram. No aneurysm-related secondary procedures were required. CONCLUSION: Routine use of through-and-through axillary-femoral guidewire associated with selective pre-cannulation of the lower renal artery allows a precise deployment of the Gore Excluder Conformable endograft in difficult anatomies possibly affecting early outcomes.

Impact of Insertion Technique and Iliac Artery Anatomy on Fenestrated Endovascular Aneurysm Repair.

Purpose: To develop a mechanically realistic aortoiliac model to evaluate anatomic variables associated with stent-graft rotation and to assess common deployment techniques that may contribute to rotation. Materials and Methods: Idealized aortoiliac geometries were constructed either through direct 3-dimensional (3D) printing (rigid) or through casting with polyvinyl alcohol using 3D-printed molds (flexible). Flexible model bending rigidity was controlled by altering wall thickness. Three flexible patient-specific models were also created based on the preoperative computed tomography angiograms. Zenith infrarenal and fenestrated devices were used in this study. The models were pressurized to 100 mm Hg with normal saline. Deployments were performed under fluoroscopy at 37°C. Rotation was calculated by tracking the change in position of gold markers affixed to the devices. Results: In the rigid idealized models, stent-graft rotation increased with increasing torsion; torsion levels of 1.6, 2.6, and 3.6 mm-1 had mean rotations of 5.2°±0.03°, 11.2°±4.8°, and 27.6°±13.0°, respectively (p<0.001). In the flexible models, the highest rotation (58°±3.0°) was observed in models with high torsion and high rigidity (7.5 mm-1 net torsion and 254 N·m2 flexural rigidity). No rotation was observed in the absence of torsion. Applying torque to the device during insertion significantly increased stent-graft rotation by an average of 28° across all levels of torsion (p<0.01). Multiple device insertions prior to deployment did not change the observed device rotation. The patient-specific models accurately predicted the degree of rotation seen intraoperatively to within 5°. Conclusion: Insertion technique plays an important role in the degree of stent-graft rotation during deployment. Our model suggests that in vivo correction of device orientation can increase the observed rotation and supports the concept of fully removing the device, adjusting the orientation, and subsequently reinserting. Additionally, increasing iliac artery torsion in the presence of increased vessel rigidity results in stent-graft rotation.

Advanced Technical Considerations for Implanting the t-Branch Off-the-Shelf Multibranched Stent-Graft to Treat Thoracoabdominal Aneurysms.

PURPOSE: To demonstrate different techniques and device modifications that can expand the anatomic suitability of the off-the-shelf multibranched t-Branch for treatment of thoracoabdominal aortic aneurysm. TECHNIQUE: The t-Branch device is not customized for specific patient anatomy, and the most frequent limitations to its use are an inadequate sealing zone and renal artery anatomy. Experience with this device has prompted the development of several techniques that can be employed to maximize the suitability of this stent-graft. Advice is offered on modification of the device to minimize the risk of paraplegia or better match patient anatomy. Maneuvers are explained to ease delivery through tortuous anatomy or existing stent-grafts, catheterize visceral target vessels, select a bridging stent, reduce ischemia time in the limbs, and alter the configuration of the branches. CONCLUSION: Employing adjunctive maneuvers can increase the anatomic suitability of the t-Branch; in our experience, these techniques have increased the applicability to more than 80% of all elective and urgent thoracoabdominal aortic aneurysm cases.

A Semiautomated Method for Measuring the 3-Dimensional Fabric to Renal Artery Distances to Determine Endograft Position After Endovascular Aneurysm Repair.

PURPOSE: To report a methodology for 3-dimensional (3D) assessment of the stent-graft deployment accuracy after endovascular aneurysm repair (EVAR). METHODS: A methodology was developed and validated to calculate the 3D distances between the endograft fabric and the renal arteries over the curve of the aorta. The shortest distance between one of the renal arteries and the fabric (SFD) and the distance from the contralateral renal artery to the fabric (CFD) were determined on the first postoperative computed tomography (CT) scan of 81 elective EVAR patients. The SFDs were subdivided into a target position (0-3 mm distal to the renal artery), high position (partially covering the renal artery), and low position (>3 mm distal to the renal artery). Data are reported as the median (interquartile range, IQR). RESULTS: Intra- and interobserver agreements for automatic and manual calculation of the SFD and CFD were excellent (ICC >0.892, p<0.001). The median SFD was 1.4 mm (IQR -0.9, 3.0) and the median CFD was 8.0 mm (IQR 3.9, 14.2). The target position was achieved in 44%, high position in 30%, and low position in 26% of the patients. The median slope of the endograft toward the higher renal artery was 2.5° (IQR -5.5°, 13.9°). CONCLUSION: The novel methodology using 3D CT reconstructions enables accurate evaluation of endograft position and slope within the proximal aortic neck. In this series, only 44% of endografts were placed within the target position with regard to the lowermost renal artery.

Push-Up Technique and Anatomical Deployment With the Endurant Stent-Graft System for Severely Angulated Aneurysm Necks.

PURPOSE: To describe a technique suitable for treating severely angulated (>75°) necks during endovascular aneurysm repair using the Endurant stent-graft. TECHNIQUE: In the push-up technique, the suprarenal stent is released early to fix the proximal stent-graft in place so that each stent in the neck can be deployed individually without displacing the device upward. It is important to push the delivery system up after each stent deployment to allow the fabric between the stents to fold up circumferentially. By doing so, there is minimal upward force applied to the suprarenal stent. Because the stents expand along the angulated neck while catching blood flow, this anatomical deployment is feasible, with hardly any change to the proximal neck shape after stent-graft implantation. CONCLUSION: The push-up technique and anatomical deployment with the Endurant stent-graft system are effective and safe methods for treating aneurysms with severely angulated necks.