Technique of implantation and bail-out maneuvers for endovascular fenestrated repair of juxtarenal aortic aneurysms

The semi-compliant balloon bounce technique for total femoral approach during fenestrated-branched endovascular aortic aneurysm repair

A total femoral approach for fenestrated-branched endovascular aortic aneurysm repair has been increasingly favored to minimize risks of aortic arch manipulation. We describe a novel technique to support the advancement of endovascular devices into a target vessel. Following catheterization of the intended target artery and deployment of the diameter-reducing ties, a Coda semi-compliant balloon (Cook Medical) is advanced and inflated immediately above the target artery. It is used as a support as the wire, catheter, or sheath "bounces" on the balloon, stabilizing the support wire to advance stent grafts, balloons, or sheaths into the downward renal or mesenteric vessels.

Intraoperative complications during standard and complex endovascular aortic repair

This study aimed to provide a comprehensive overview of the most common intraoperative adverse events that occur during standard endovascular repair and fenestrated-branched endovascular repair to treat abdominal aortic aneurysms, thoracoabdominal aortic aneurysms, and aortic arch aneurysms. Despite advancements in endovascular techniques, sophisticated imaging and improved graft designs, intraoperative difficulties still occur, even in highly standardized procedures and high-volume centers. This study emphasized that with the increased adoption and complexity of endovascular aortic procedures, strategies to minimize intraoperative adverse events should be protocolized and standardized. There is a need for robust evidence on this topic, which could potentially optimize treatment outcomes and durability of the available techniques.

Fenestrated/branched endovascular aortic repair using unilateral femoral access in patients with iliac occlusive disease

OBJECTIVE

Fenestrated/branched endovascular aortic repair (F/BEVAR) in patients with occluded iliac arteries is challenging owing to limited access for branch vessel catheterization and increased risk for leg and spinal ischemic complications. The aim of this study was to analyze technical strategies and outcomes of F/BEVAR in patients with unilateral iliofemoral occlusive disease.

METHODS

We performed a retrospective review of all consecutive patients treated by F/BEVAR in two institutions (2003-2021). Patients with unilateral iliofemoral occlusive disease were included in the analysis. All patients had one patent iliac artery that was used for advancement of the fenestrated-branch component. Preloaded catheter/guidewire systems or steerable sheaths were used as adjuncts to facilitate catheterization. Primary endpoints were technical success, mortality, major adverse events (stroke, spinal cord injury, dialysis or decrease in the glomerular filtration rate of more than 50%, bowel ischemia, myocardial infarction, or respiratory failure), primary iliac patency, and freedom from reinterventions.

RESULTS

There were 959 patients treated with F/BEVAR. Of these, 15 patients (1.56%; mean age, 74 years; 80% male) had occluded iliac arteries and 1 patent iliofemoral access and were treated for a thoracoabdominal aortic aneurysm (n = 8) or juxtarenal abdominal aortic aneurysm (n = 7). Brachial access was used in 14 of the 15 patients and preloaded systems in 7 of the 15 patients (47%). The remaining 53% had staggered deployment of stent grafts. There were seven physician-modified endovascular grafts, seven custom-made devices, and one off-the-shelf device used. Thirteen patients (87%) had distal seal using aortouni-iliac stent grafts and two (13%) had distal seal in the infrarenal aorta. Concomitant femoral crossover bypass (FCB) was performed in two patients and six patients had a prior FCB. Technical success was 100%. There were no intraoperative complications or early lower extremity ischemic complications, and all FCB were preserved. There was one mortality (7%) within 30 days owing to retrograde type A dissection. Major adverse events occurred in 20% of patients. The median follow-up was 12 months (range, 0-85 months). Two patients (13%) required three reinterventions. One patient required proximal stent graft extension for an acute type B dissection (3 months) and another required iliac extension for type Ib endoleak of an aortouni-iliac graft (21 months) and thrombolysis of that extension (50 months). At last follow-up, all patients had primary graft patency except one with secondary graft patency without new claudication. One patient had a single renal artery stent occlusion at follow-up with no r-intervention. The overall survival rate was 60%, without aortic-related deaths.

CONCLUSIONS

Although challenging, F/BEVAR with unilateral femoral/brachial approach is feasible in patients with occluded iliac limbs, with an important rate of ischemic complications, but satisfactory outcomes.

Five-year outcomes of physician-modified endografts for repair of complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

There is paucity of data on the durability of physician modified endografts (PMEGs) for complex abdominal (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs) despite widespread use. The aim of this study was to evaluate and compare the early and long-term outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) for CAAAs and TAAAs using PMEGs.

METHODS

We reviewed clinical data and outcomes of patients treated by FB-EVAR using PMEGs for CAAAs (defined as short-neck infrarenal, juxtarenal, and pararenal AAAs) and TAAAs between 2007 and 2019. All patients were treated by a dedicated team with extensive manufactured device experience. Endpoints included 30-day mortality and major adverse events, patient survival and freedom from aortic-related mortality (ARM), freedom from secondary intervention, target artery (TA) patency, and freedom from TA endoleak and TA instability.

RESULTS

Of 645 patients undergoing FB-EVAR, 156 patients (24%) treated with PMEG (121 males; mean age, 75 ± 8 years) were included. There were 89 CAAAs, 33 extent IV TAAAs and 34 extent I to III TAAAs. A total of 452 renal-mesenteric targets (3.1 ± 1.0 vessels/patient) were incorporated. Patients with TAAAs had significantly (P < .05) larger aneurysms (73 ± 11 vs 68 ± 14 mm), more TAs incorporated (3.4 ± 0.9 vs 2.8 ± 1.0), and more often had previous aortic repair (54% vs 27%). Technical success was higher in patients treated for CAAAs (99% vs 91%; P = .04). Thirty-day and/or in-hospital mortality was 5.7% and was significantly lower for CAAAs compared with TAAAs (2% vs 10%; P = .04), with three of nine early mortalities (33%) among patients treated emergently. After a mean follow-up of 49 ± 38 months, there were 12 aortic-related deaths (7.6%), including nine early deaths (5.7%) from perioperative complications and three late deaths (1.9%) from rupture. At 5 years, patient survival was 41%. Patients treated for CAAAs had higher 5-year freedom from ARM (P = .016), TA instability (P = .05), TA endoleak (P = .01), and TA secondary interventions (P = .05) with a higher, but non-significant, freedom from sac enlargement ≥5 mm (P = .11). Primary and secondary TA patency was 91% ± 2% and 99% ± 1%, respectively. Sac regression ≥5 mm occurred in 67 patients (43%) and was associated with increased survival (hazard ratio, 0.54; 95% confidence interval, 0.37-0.80) compared with those without sac regression.

CONCLUSIONS

FB-EVAR using PMEGs was performed with acceptable long-term outcomes. Overall patient survival was low due to significant underlying comorbidities. Patients treated for CAAAs had higher freedom from ARM, TA instability, TA endoleak, TA secondary interventions, and a trend towards higher freedom from sac enlargement compared with patients treated for TAAAs. Sac regression was associated with improved patient survival.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Contemporary Management of Abdominal Aortic Aneurysms

PURPOSE OF REVIEW

Abdominal aortic aneurysms (AAA) can carry extremely high mortality rates and most will only present with symptoms with impending rupture. We present an overview of management of this disease process starting with screening, to medical management, surveillance and treatment options currently available, as well as those being studied for future use.

RECENT FINDINGS

Screening has been proven to reduce the mortality rate. There still remains a paucity of data to support medical therapies to help mitigate the rate of aneurysm growth and prevent rupture. However, on the topic of repair, there have been advancements in endovascular devices which have broadened the scope of treatment for patients with anatomy not amenable to standard endovascular repair or those who are not suitable candidates for open surgical repair. Appropriate surveillance, risk factor modification, and operative repair, when indicated, are the cornerstones of contemporary management of AAAs. Advancements in endovascular technologies have allowed us to treat more patients. Further research is warranted on non-operative medical therapies.

Floating Stent-Graft as a Support to Bridge an Unfavorable Renal Artery During Postdissection TAAA Repair Using a Multibranched Thoracoabdominal Endograft

Purpose: To report an unusual endovascular technique to manage unfavorable renal artery anatomy encountered in an urgent case of symptomatic postdissection thoracoabdominal aortic aneurysm (TAAA) treated with an off-the-shelf multibranched device. Technique: The technique is demonstrated in a 77-year-old woman who had a history of previous open abdominal aortic aneurysm repair and an emergent procedure to implant a thoracic endograft and an aortic bare Z-stent (PETTICOAT) for acute Stanford type B dissection 7 years prior. The patient presented with a symptomatic, rapidly growing, postdissection TAAA. Endovascular treatment with a Zenith t-Branch was planned. After standard catheterization techniques failed in the left renal artery, a bailout maneuver was utilized to place a "floating" Viabahn stent-graft in the aneurysm sac to create sufficient support to deliver the bridging stent-grafts through the bare stent to the target left renal artery. The procedure was successful in excluding the TAAA and preserving perfusion to all target vessels. No neurological complications occurred. Six-month imaging follow-up confirmed the patency of the bridging stents. Conclusion: Remodeling changes after complex endovascular TAAA procedures often require the use of innovative techniques and materials during secondary procedures. In this case, the presence of a post-PETTICOAT bare aortic stent and hostile target artery anatomy increased the technical difficulty of t-Branch implantation. A "floating" stent-graft could be useful to reach challenging target vessels by providing additional support to bridging stent advancement and deployment.

Endovascular Treatment for Thoracoabdominal Aortic Aneurysm and Complex Abdominal Aortic Aneurysm Using Fenestrated and Branched Grafts

Fenestrated and branched endovascular aneurysm repair (F/B-EVAR) is a less invasive treatment for thoracoabdominal aortic aneurysm (TAAA) and complex abdominal aortic aneurysm. Fenestrated and branched (cuff) grafts facilitate safe and durable repair, and bail-out maneuvers for target vessel cannulation and stenting have been established; however, the available bridging stent grafts have differences. The present article discusses the optimal selection of fenestrated or branched grafts, the cannulation of target vessels that have difficult anatomies, and the advantages and disadvantages of various bridging stents. We review the causes and risk factors of spinal cord injury (SCI), the protocol for prevention of SCI, and the outcomes of target vessel stent grafting, including patency and endoleak.

Although conventional open surgery is the gold standard for the repair of thoracoabdominal aortic aneurysm (TAAA), it is highly invasive. To reduce invasiveness, hybrid surgery that combines open surgery and endovascular therapy has been developed [1, 2], and fenestrated and branched endovascular aneurysm repair (F/B-EVAR) is frequently performed at centers in the USA, Europe, and Japan [3-5]. Additionally, a hostile neck may be an independent factor for sac enlargement after EVAR for abdominal aortic aneurysm (AAA) [6], but a previous study reported that 41% of AAA cases presented with neck lengths outside the range prescribed by the traditional instruction for use [7]. Stark et al. showed that extending the graft above the highest renal artery would create an augmented neck length in 90% of patients with AAA [7]. F/B-EVAR is based on this principle. However, there are some technical tips for, and limitations of, fenestrated and/or branched graft. F/B-EVAR for TAAA and complex AAA will be reviewed in the present article.

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.

Structural implications of fenestrated stent graft misalignment

BACKGROUND

Endovascular aneurysm repair is a minimally-invasive method for the treatment of abdominal aortic aneurysms. For aneurysms that involve the visceral arteries, a custom-made stent graft with fenestrations for the branch arteries is required. The purpose of the current study is to evaluate the structural impact of misaligned fenestrations with respect to luminal patency and proximal aortic neck apposition in an in vitro model.

METHODS

A custom apparatus was used to evaluate seven Anaconda and three Zenith fenestrated stent grafts. All stent grafts were evaluated at 10° increments of stent/fenestration misalignment up to 80°. Images were captured at each interval and the luminal cross-sectional area and wall apposition were measured.

RESULTS

The Anaconda stent graft, which has an unsupported main body, demonstrated a linear reduction in luminal patency at increasing angles of misalignment (P < 0.0001). Stent/fenestration misalignments of 20° and 80° resulted in decreases in mean luminal patency of 14% and 54% respectively. The Zenith stent graft demonstrated a similar decrease in luminal patency, starting at misalignments of ≥40° (P < 0.0001). However, with stent/fenestration misalignments of ≥30°, apposition between the Zenith stent graft and the simulated aortic neck was compromised suggesting the creation of a type Ia endoleak.

CONCLUSIONS

Both the Anaconda and Zenith devices behave adversely at extreme angles of misalignment with luminal narrowing in the Anaconda device and loss of wall apposition in the Zenith device; however, both stent grafts appear to be equivalent at low angles of misalignment.

Balloon-Assisted Tracking: A Solution to Severe Subclavian Tortuosity Encountered During Transradial Primary PCI

Radial artery access is preferred over femoral access for primary percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction because of the reduction in access site complications and mortality associated with the radial artery access. Successful transradial primary PCI requires knowledge of techniques to handle unexpected severe subclavian artery tortuosity. Balloon-assisted tracking (BAT) is one technique developed to negotiate the tortuosity and loops in the upper extremity. However, the use of BAT in dealing with a severe subclavian loop during a transradial primary PCI procedure has never been reported. We described a case of transradial primary PCI with severe subclavian artery loop that was negotiated successfully by the BAT technique.

Endovascular repair of a juxtarenal saccular aneurysm using the Multilayer Flow Modulator: report of the first case performed in a Public Hospital in Brazil

Endovascular treatment of abdominal aortic aneurysms (AAA), involving the exits of the renal and visceral arteries still constitutes a considerable challenge. Many different techniques have been developed over the years in attempts to surmount the difficulties presented by these cases. Techniques that have gained prominence include fenestrated or branched stents, methods involving parallel prostheses, such as the chimney, periscope and sandwich techniques, and, more recently, flow modulation with Multilayer stents. We describe a case of a complex juxtarenal saccular AAA with a high surgical risk, both according to cardiological assessment and because the patient had a difficult airway caused by a total laryngectomy for early stage laryngeal neoplasm. In view of the technical simplicity of using Multilayer stents, the presence of chronic obstructive aortoiliac disease, ostial stenosis of the renal artery and a small diameter suprarenal aorta, options involving fenestrated/branched stents and techniques involving parallel prostheses were ruled out, because of the need for multiple accesses. In view of the dilemma it presented, we describe this case as a therapeutic challenge and present the treatment option employed, which has been successful over the short term.