Treatment of short-necked infrarenal aortic aneurysms with fenestrated stent-grafts: short-term results

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair

OBJECTIVE

Fenestrated endovascular aneurysm repair (FEVAR) is a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as a treatment for failed EVAR. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine midterm outcomes and aneurysm sac dynamics of FEVAR after prior EVAR.

METHODS

Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality rate, one year aneurysm sac dynamics (regression, stable, expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi square tests, and linear mixed effect models.

RESULTS

One hundred and ninety-six patients with FEVAR were identified, of whom 27% (n = 53) had had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality rate. FEVAR after EVAR was associated with a higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001).

CONCLUSION

There were high rates of sac expansion and a need for more secondary procedures in FEVAR after EVAR than primary FEVAR patients, although this did not affect midterm survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

[Endovascular aortic repair: the hostile aneurysm neck : Morphologic definition, impact on long-term outcome, and treatment options]

DEFINITION

A hostile neck is defined by various anatomical conditions that describe a morphology of the proximal aneurysmal neck of infrarenal aortic aneurysms that is unfavorable for endovascular treatment (endovascular aortic repair, EVAR): proximal landing zone length ≤ 15 mm, angulation of the aortic neck > 60°, conical aortic neck, diameter of the aortic neck > 32 mm, and circumferential calcification/thrombus.

EFFECTS ON OUTCOME

These morphological parameters are not only associated with a higher perioperative technical failure rate (primary type 1 endoleak) but also with poorer long-term results (secondary type 1 endoleak) and thus a higher reintervention rate in standard EVAR, so that standard EVAR should be reserved for a few exceptions in these cases.

TREATMENT OPTIONS

Due to the rapid development of endovascular techniques in the last decade, we now have a variety of endovascular options for aneurysms with hostile necks, for both elective treatment and emergency care, in addition to conventional open surgery, which is still the standard method in many cases and is currently undergoing a renaissance: fenestrated endovascular aortic repair (FEVAR) as the method of first choice in the elective setting, EVAR with chimneys (ChEVAR), endosuture aneurysm repair (ESAR). An important option is the conservative approach, which can be a reasonable choice if the patient's preference is taken into account and a careful risk-benefit assessment is performed.

Reporting standards for endovascular aortic repair of aneurysms involving the renal-mesenteric arteries

Endovascular aortic aneurysm repair of complex aortic aneurysms requires incorporation of side branches using specially designed aortic stent grafts with fenestrations, directional branches, or parallel stent grafts. These techniques have been increasingly used and reported in the literature. The purpose of this document is to clarify and to update terminology, classification systems, measurement techniques, and end point definitions that are recommended for reports dealing with endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms involving the renal and mesenteric arteries.

Outcomes of elective use of the chimney endovascular technique in pararenal aortic pathologic processes

OBJECTIVE

In the treatment of pararenal abdominal aortic aneurysms and aortic pathologic processes, chimney endovascular aneurysm repair (CHEVAR) represents an alternative technique for urgent cases. The aim of the study was to evaluate the outcomes of CHEVAR in the elective setting.

METHODS

We performed a retrospective analysis of prospectively collected records of 165 consecutive asymptomatic CHEVAR patients who were treated between March 2009 and January 2018 with the Endurant stent graft (Medtronic, Santa Rosa, Calif). A total of 244 chimney grafts (CGs) were implanted. The primary end point was clinical success, defined as freedom from procedure-related mortality, persistent type IA endoleak, occlusion or high-grade stenosis (>70%) of CGs, and any chimney technique-related secondary procedure for the entire follow-up period. Secondary clinical success included patients with successful treatment of a primary end point with a secondary endovascular procedure.

RESULTS

All 244 targeted chimney vessels were successfully cannulated. Total perioperative morbidity was 7.8% (n = 13), including 3 (1.8%) cases of bowel ischemia, 1 (0.6%) patient with renal ischemia, and 1 patient (0.6%) with stroke. Median follow-up was 25.5 ± 2.2 months. Both 30-day and follow-up procedure-related mortality rates were 1.8% (n = 3). Primary and secondary freedom from persistent type IA endoleak rates were 96.4% (n = 159) and 99.4% (n = 164), respectively. Primary and secondary CG patency rates were 92.2% (n = 225) and 95.9% (n = 234), respectively. The rate of reinterventions related to the chimney technique was 10.9% (n = 18), and 83.3% of them were performed by endovascular means. The estimated cumulative primary patency and freedom from persistent type IA endoleak were 87.5% and 95.3%, respectively, and the primary and secondary clinical successes rates at midterm were 80.3% and 87.5%, respectively.

CONCLUSIONS

The elective use of CHEVAR with the Endurant stent graft in our series showed favorable midterm clinical results, which are similar to the published results of other total endovascular modalities. A prospective randomized trial of elective treatment of pararenal abdominal aortic aneurysms and aortic pathologic processes with current endovascular options is needed to assess the value of CHEVAR in the elective setting.

Fenestrated-branched endovascular aortic repair in patients with chronic kidney disease

OBJECTIVE

Renal function impairment is a common complication after open repair of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs). The purpose of this study was to assess renal perioperative outcomes and renal function deterioration after fenestrated-branched endovascular aneurysm repair (F/BEVAR) in patients with chronic kidney disease (CKD).

METHODS

The study included 186 patients who underwent F/BEVAR between 2013 and 2018 for suprarenal, juxtarenal, and type I to type IV TAAAs. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Postoperative acute kidney injury (AKI) and CKD were defined using RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage renal disease) and CKD staging system (stage ≥3, GFR <60 mL/min/1.73 m²), respectively. For those without baseline CKD, renal decline was defined as a drop in GFR <60 mL/min/1.73 m² (ie, progression to CKD stage 3 or higher). For patients with baseline renal dysfunction, GFR decline ≥20% or progression in CKD stage (ie, from stage 3 to stage 4) was considered renal decline.

RESULTS

CKD was present in 83 patients (44.6%). Postoperative AKI was diagnosed in 27 patients (14.5%); 13 (48.1%) had history of CKD and 14 (51.9%) had adequate renal function preoperatively (P = .8). None of these patients required permanent renal replacement therapy. Intraoperative technical success was 100%. Overall 30-day mortality was 1.1%. There was no difference in 30-day mortality in patients with (1.2%) and without (1.0%) CKD (P = .5). During a median follow-up time of 12 months (interquartile range, 6-23 months), renal decline was observed in 21 patients (25.3%) with previous CKD and in 11 patients (10.6%) without CKD (P = .01). Among patients with previous CKD, 18 patients (9%) progressed from stage 3 CKD to stage 4. In patients with progression in CKD stage, two (5%) had renal stent stenosis requiring restenting. Among patients with renal decline, 13 had juxtarenal aneurysms (21.3%), 27 had suprarenal aneurysms (44.3%), and 21 had TAAAs (34.3%; P = .4). Subset analysis of patients who developed AKI in the immediate postoperative period found that patients with a history of CKD were less likely to experience freedom from renal decline.

CONCLUSIONS

F/BEVAR is an effective and safe procedure for patients with complex abdominal aortic aneurysms and TAAAs, even among patients with CKD. The frequency of AKI was not affected by pre-existing CKD. Midterm outcomes demonstrated that progression of CKD was more frequent among patients with pre-existing CKD, but permanent renal replacement therapy was not required. Anatomic extent of aneurysms did not affect CKD progression. CKD patients are susceptible to renal decline over time if they experience AKI in the postoperative period. Therefore, preventing AKI in the postoperative period should be regarded as a priority. Long-term effects of CKD after F/BEVAR remain to be elucidated.

Fenestrated Endovascular Aneurysm Repair versus Snorkel Endovascular Aneurysm Repair: Competing yet Complementary Strategies

Juxtarenal/pararenal aortic aneurysms and type IV thoracoabdominal aneurysms pose particular technical challenges for endovascular repair as they involve the visceral segment in addition to insufficient infrarenal neck for the use of standard endovascular aneurysm repair (EVAR) devices. To overcome these challenges, complex EVAR techniques have been developed to extend the proximal landing zone cephalad with maintaining perfusion to vital aortic branches, thereby broadening the applicability of endografting from the infrarenal to the suprarenal aorta. Complex EVAR can be divided into two broad categories: fenestrated endovascular aneurysm repair (FEVAR) and snorkel EVAR. FEVAR is a valid procedure with the standardized procedure, although it remains as a relatively complex procedure with a learning curve. Given time constraints for the custom fenestrated graft, snorkel EVAR may be an alternative for complex repairs in symptomatic or ruptured patients for whom custom-made endografts may not be immediately available. This article discusses these two most commonly used complex EVAR strategies.

New Large Animal Model for Aortic Aneurysms in the Viscerorenal Segment

BACKGROUND

Aortic aneurysms in the viscerorenal-segment are nowadays treatable by endovascular means. Previously, new endograft techniques were only tested in healthy animals. We aimed to establish a new large animal model for testing complex endovascular stent techniques preclinically.

METHODS

In sheep, four juxtarenal and two type IV thoracoabdominal aortic aneurysms were surgically created via a retroperitoneal approach. Two pieces out of a 10 × 15-cm bovine pericardial patch were sewn with the healthy aorta longitudinally. The viscerorenal segment was clamped, and the aorta was incised longitudinally. Then, the patches were longitudinally sewn together. In the meantime, antegrade flow through the native part of the aorta was already established by tangential clamping. Computed tomography angiography was performed after 4, 8, and 52 wk.

RESULTS

Technical success was 100%. The median surgical procedure time was 3 h, the median blood loss was 210 mL, and the viscerorenal-segment clamping time was 2-4 min. The animals started drinking 1 h after arousal from anesthesia. One animal died after 1 wk because of delayed bleeding and another died after 1 y because of aneurysm rupture by a secondary bacterial infection. Four animals survived. The proximal landing zone diameter and the clock position of the vessel were stable over 52 wk.

CONCLUSIONS

Surgical creation of an aortic aneurysm in the viscerorenal-segment in sheep was successful, without an ischemia/reperfusion injury. This animal model offers a new platform for evaluating innovative endovascular therapy options in vivo.

Rescue of proximal failure of endovascular abdominal aortic aneurysm repair with standard and fenestrated grafts

BACKGROUND

This study aimed to assess the outcomes of standard and fenestrated grafts to treat proximal failure of previous endovascular aneurysm repair (EVAR) in a tertiary referral center.

METHODS

All patients undergoing elective implantation of a standard or fenestrated graft after proximal failure of a previous EVAR between April 2010-November 2018 were included. Data were collected prospectively.

RESULTS

Fifty procedures were performed in 49 patients (45 male; mean age 74.6±7 years). A fenestrated proximal cuff was used in 24 (48%) cases, a composite bifurcated configuration in 21 (42%) cases, and EVAR in 5 (10%) cases. Technical success was achieved in all 5 EVAR cases and 41 of 45 FEVAR cases (91.1%). Iliac artery access problems due to the presence of the previous graft were encountered in eight (16%) procedures and renal artery catheterization difficulties in grafts with suprarenal fixation in seven (15.6%) procedures. There was one (2%) early death due to retroperitoneal bleeding. Early major complications occurred in three (6%) patients. Median follow-up was 26 months (range 1-77). Late occlusion occurred in two (1.3%) of the 151 targeted vessels. One patient needed permanent dialysis. Nine patients died during follow-up, one (2%) of them aneurysm-related. Ten (20.4%) patients presented with major complications during follow-up of which nine (18.4%) needed reintervention. Estimated freedom from reintervention at 1 and 3 years was 89.3±5.1% and 78.8±7.3%, respectively.

CONCLUSIONS

Repair with fenestrated grafts represents a safe and effective treatment option. Increased technical challenges are to be expected due to the previous graft.

The role of selective stenting for superior mesenteric artery scallops during fenestrated endovascular aneurysm repair

OBJECTIVE

Stenting of small fenestrations of the Zenith fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) is necessary during fenestrated endovascular aneurysm repair (FEVAR) of complex abdominal aortic aneurysms to avoid malalignment. However, stenting of superior mesenteric artery (SMA) scallops of ZFEN devices is optional according to the instructions for use. The objective of this study was to assess the early and midterm outcomes of selective use of stents in SMA scallops of ZFEN during FEVAR procedures.

METHODS

This study is a single-institution retrospective review of prospectively enrolled patients treated at the University of North Carolina at Chapel Hill between July 2010 and August 2014. Only patients with SMA scallops were included for analysis. We compared results between patients grouped as stented or unstented SMA scallops. The scallops were stented when one or more of the following criteria were present: misalignment of scallop determined by balloon testing intraoperatively; configuration consisting of an SMA scallop and a single renal fenestration or stent; and pre-existing stenosis in the vessel adjacent to the graft scallop. The study was approved by the local Institutional Review Board. Primary outcomes addressed were mortality, vessel patency, early and late complications, and reintervention rates. Baseline characteristics of the patients and procedure data were also described.

RESULTS

During the 48-month study period, 61 patients were treated for complex abdominal aortic aneurysms at the University of North Carolina with a mean age of 73 years, and 74.3% of patients were male. Thirty-nine of 61 patients (63.9%) had a device design with an SMA scallop and were included for analysis. Eleven of 39 patients (28%) had the SMA primarily stented and 28 (72%) were unstented. There was only one death (2.5%) during the 30-day postoperative period, with 100% technical success and branch patency. In the unstented group, there were three SMA complications during follow-up, two requiring reintervention; however, there were no associated deaths. Among the stented group, there was one branch-related complication that occurred during the procedure but no stent stenosis or occlusion during the long-term follow-up. During the mean follow-up period of 21.7 months, no SMA stent thrombosis occurred. There was no statistical difference in outcomes between groups.

CONCLUSIONS

Single-wide SMA scallops of ZFEN during FEVAR procedures may be selectively stented using specific criteria and rigorous follow-up, without compromising the safety and efficacy of the SMA.

Three-vessel fenestrated and bilateral iliac branched graft repair of a juxtarenal aortic aneurysm with bilateral common iliac aneurysms

We describe a patient with large bilateral common iliac artery aneurysms as well as a large juxtarenal abdominal aortic aneurysm successfully treated by a novel approach. The procedure, completed in one setting, involved this sequence: positioning and deployment of bilateral iliac branch grafts with appropriate internal iliac limbs; insertion of a three-vessel fenestrated proximal device with cannulation and stenting of the left renal artery; and positioning and deployment of a bifurcated endograft and two mating limbs to the bilateral iliac branch device. The procedure was completed with percutaneous access; the patient recovered well and was discharged on postoperative day 1.

Fenestrated and Branched Stent Grafting in Complex Aneurysmatic Aortic Disease: A Single-Center Early Experience

BACKGROUND

The aim of this study is to present our early experience and highlight the technical difficulties associated with the use of fenestrated and branched stent grafts to treat patients with juxtarenal abdominal aortic aneurysm (AAA), pararenal AAA, and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A prospectively held database maintained at our department was queried for patients who have undergone branched and fenestrated stent grafting for AAA or TAAA treatment. Indication for repair, comorbidity precluding open repair, technical challenges associated with the repair, as well as operative mortality, morbidity, and reintervention rate were evaluated.

RESULTS

A total of 8 patients underwent repair with a fenestrated or branched stent graft. All patients had aneurysmal degeneration of the juxtarenal aorta, pararenal aorta, and thoracoabdominal aorta not suitable to standard endovascular techniques. Two patients had a prior aortic repair, a failed migrated stent graft, and an old surgical tube graft after an open repair. One patient had a type III TAAA and 1 patient had a postdissection TAAA type I. For all patients, target vessel success rate was 96.4% (27/28) and mean hospital stay was 6.0 days (range 3-21). Thirty-day and 1-year mortality were 0%. Mean follow-up was 23 months (range 7-45). Two endoleaks occurred, 1 type III and 1 type II, which were treated endovascularly. No death or major complication occurred during follow-up.

CONCLUSIONS

Fenestrated and branched endovascular stent grafts can be used to repair juxtarenal AAA, pararenal AAA, and TAAA in patients with significant comorbidities. However, several technical challenges have to be overcome due to the unique complex aortic pathology of each patient.

Effect of a Flared Renal Stent on the Performance of Fenestrated Stent-Grafts at Rest and Exercise Conditions

PURPOSE

To quantify the hemodynamic impact of a flared renal stent on the performance of fenestrated stent-grafts (FSGs) by analyzing flow patterns and wall shear stress-derived parameters in flared and nonflared FSGs in different physiologic scenarios.

METHODS

Hypothetical models of FSGs were created with and without flaring of the proximal portion of the renal stent. Flared FSGs with different dilation angles and protrusion lengths were examined, as well as a nonplanar flared FSG to account for lumbar curvature. Laminar and pulsatile blood flow was simulated by numerically solving Navier-Stokes equations. A physiologically realistic flow rate waveform was prescribed at the inlet, while downstream vasculature was modeled using a lumped parameter 3-element windkessel model. No slip boundary conditions were imposed at the FSG walls, which were assumed to be rigid. While resting simulations were performed on all the FSGs, exercise simulations were also performed on a flared FSG to quantify the effect of flaring in different physiologic scenarios.

RESULTS

For cycle-averaged inflow of 2.94 L/min (rest) and 4.63 L/min (exercise), 27% of blood flow was channeled into each renal branch at rest and 21% under exercise for all the flared FSGs examined. Although the renal flow waveform was not affected by flaring, flow within the flared FSGs was disturbed. This flow disturbance led to high endothelial cell activation potential (ECAP) values at the renal ostia for all the flared geometries. Reducing the dilation angle or protrusion length and exercise lowered the ECAP values for flared FSGs.

CONCLUSION

Flaring of renal stents has a negligible effect on the time dependence of renal flow rate waveforms and can maintain sufficient renal perfusion at rest and exercise. Local flow patterns are, however, strongly dependent on renal flaring, which creates a local flow disturbance and may increase the thrombogenicity at the renal ostia. Smaller dilation angles, shorter protrusion lengths, and moderate lower limb exercise are likely to reduce the risk of thrombosis in flared geometries.

Modular Branched Endograft System for Aortic Aneurysm Repair: Evaluation in a Human Cadaver Circulation Model

A circulation model was created in 6 nonaneurysmal human cadavers to evaluate the deliverability, deployment, and acute performance of a modular branched endograft system for treatment of aortic aneurysms containing essential branch vessels. Two fenestrations were created in an appropriately sized aortic main endograft. Under fluoroscopic guidance, the main endograft was advanced to the target site and the fenestrations were aligned with the ostia of the renal arteries. Branch grafts were placed through the fenestrations into the renal arteries. The outcome was evaluated by post implant angiography and autopsy. Eleven branch grafts were deployed at the target site. All targeted renal arteries showed good patency. At autopsy, all main endografts were adequately deployed, and 10 of 11 branch grafts were locked in place. In this model, deliverability and deployment of the modular branch graft system is feasible in a reliable, predictable, and timely fashion.

Fenestrated Endografting for Aortic Aneurysm Repair: A 7-Year Experience

Purpose:

To present a 7-year single-center clinical experience with fenestrated endografts and side branches.

Methods:

Between April 1999 and August 2006, 63 patients (57 men; mean age 70.5611.6 years, range 25–89) received custom-designed Zenith fenestrated endoprostheses for a variety of aneurysms (59 abdominal, 1 thoracoabdominal, and 3 thoracic). They were all unsuitable for standard EVAR owing to short aortic necks and high risk for open surgery.

Results:

Nineteen tube grafts and 44 composite bifurcated grafts with a total of 122 fenestrations and 58 side branches were used. Technical success was achieved in 55 (87.3%) patients and in 118 (96.7%) vessels. Treatment success was 93.7%. The mean follow-up was 23±18 months (median 14, range 6–77). Overall, 9 (7.4%) visceral branches were lost: 4 intraoperative, 2 perioperative, and 3 late. There were 12 (19.0%) endoleaks identified: 5 (7.9%: 4 type Ia and 1 fenestration-related type III) primary and 7 (11.1%: 4 type II, 1 type I, and 2 type III) secondary endoleaks; 4 resolved, 4 were treated, and 4 are under observation. At 77 months, 75.3% of patients were free of a reintervention. All reinterventions were performed within the first 14 months. Fourteen cases of renal impairment were seen [6 permanent (only 1 on dialysis) and 8 transient]. One (1.6%) conversion and 1 (1.6%) rupture were recorded; aneurysm-related mortality was 4.8% (3/63).

Conclusion:

The favorable outcomes in this study, which encompasses the team's learning curve with fenestrated endografts and side branches, support the use of these devices in selected patients.

Comparison of the Fixation Strength of Standard and Fenestrated Stent-Grafts for Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To determine whether fenestrated stent-grafts provide better stability to resist migration than standard non-fenestrated stent-grafts.

Methods:

Truncated fenestrated stent-grafts with a single fenestration were deployed in bovine aortic segments with a side branch. Balloon-expandable stents were then delivered into the branches. Similarly, standard stent-grafts of the same dimensions were deployed for comparison. The aorta was pressurized to achieve stent-graft oversizing of 5%, 10%, or 20%. The force required to cause distal migration was recorded by a digital force gauge attached to the stent-graft.

Results:

Displacement of the stent-grafts occurred in 2 distinct phases: an initial yield during which the barbs embedded in the aortic wall and a final displacement leading to significant migration and dislodgement of the device. The displacement force that initiated each phase was dependent upon the degree of oversizing of the stent-graft relative to the aortic diameter. For 5%, 10%, and 20% oversizing, the mean displacement forces in the initial displacement phase were 3.39±0.37, 4.32±0.63, and 7.69±1.18 N, respectively, in non-fenestrated grafts and 10.48±1.23, 11.45±1.48, 12.12±1.42 N in fenestrated grafts. The displacement forces in the final displacement phase were 8.10±0.92, 10.76±1.74, and 16.82±0.92 N for non-fenestrated and 22.56±1.60, 28.24±1.56, and 33.01±1.75 N for fenestrated stent-grafts. The differences in displacement forces between standard and fenestrated stent-grafts were significant for both phases (p<0.001) at all oversizing levels.

Conclusion:

Improvement in fixation strength was noted with increasing stent-graft oversizing of up to 20%. Fenestrated stent-grafts offer higher ultimate fixation compared to standard devices. However, the ultimate fixation strength was not recruited until an initial phase of short migration occurred as the barbs engaged. While this movement is inconsequential with standard stent-grafts, it has the potential to crush the stents placed into aortic side branches with fenestrated endografts.

Fenestrated and Branched Grafts for Para-Anastomotic Aortic Aneurysm Repair

Purpose:

To investigate the use of fenestration and branch artery stenting during endovascular stent-graft repair of para-anastomotic aneurysms (PAA).

Methods:

A retrospective review was conducted of 9 patients (all men; mean age 71 years, range 60–80) who received custom-designed fenestrated endoprostheses for PAA repair. Eight tubular fenestrated devices and 1 composite device (fenestrated tube plus modular bifurcated body) with a total of 31 fenestrations were used.

Results:

The mean operating time was 318±93 minutes (range 220–485); the mean fluoroscopy time was 77±38 minutes (range 39–158), during which a mean 121±81 mL (range 33–300) of contrast was used. Technical success was achieved in all cases. Over a mean follow-up of 12±5.5 months (range 6–24), 1 secondary intervention was carried out due to a break in a side branch stent-graft; 2 transient renal impairments and 1 permanent renal insufficiency unrelated to renal artery patency were observed. So far, no vessel loss has emerged.

Conclusion:

Conventional repair of PAA has been a standard procedure for many years, though it carries high surgical risk as well as perioperative mortality. Fenestrated endografts may be a promising alternative in selected patients.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

Fenestrated stent graft in treatment of type IV thoracoabdominal aneurysm involving all visceral arteries

Conventional open surgical repair of thoracoabdominal aortic aneurysm (TAAA) is associated with high perioperative mortality and morbidity risk. Our report of successful treatment of a 56-year-old patient with TAAA involving all visceral arteries and with many comorbidities with a fenestrated stent graft supports its application in high-risk TAAA patients.

The Current State of Fenestrated and Branched Devices for Abdominal Aortic Aneurysm Repair

Endovascular abdominal aortic aneurysm repair (EVAR) provides an attractive alternative to traditional open techniques. Endovascular repair is frequently limited by aortic aneurysm neck angulation, the absence of an adequate infrarenal neck, and the need for internal iliac preservation. Several devices have been created to incorporate visceral artery segments as well as preserve the internal iliac artery, thus broadening the patient population suited for endovascular repair. This article will provide a review of the current literature regarding fenestrated devices, branch devices, off-the-shelf devices, and physician-modified devices. It will also highlight the iliac branch stent grafts currently on trial for internal iliac artery preservation. Data thus far have suggested that these devices will be both a safe and effective option for anatomically challenging abdominal aortic aneurysms.

Retrograde Target Vessel Catheterization as a Salvage Procedure in Fenestrated/Branched Endografting

Purpose: To present retrograde target vessel catheterization as a bailout technique in fenestrated and branched endografting (F/B-EVAR). Methods: Between November 2003 and November 2014, 11 (1.6%) of 671 consecutive patients with juxtarenal, suprarenal, and thoracoabdominal aortic aneurysms required retrograde target vessel access as a bailout measure during F/B-EVAR due to failure of an antegrade approach. The target vessels involved the left renal artery (LRA) in 6 patients, the celiac artery (CA) in 3 patients, the right renal artery (RRA) in 1 patient, and both renal arteries in 1 patient. Results: The target vessels were successfully catheterized and secured with stent-grafts in 10 patients; a single case was unsuccessful because the fenestration was in the wrong position and blocked against the arterial wall. One (9.1%) patient died within 30 days. Major perioperative complications occurred in 6 patients, including 3 with renal function deterioration, 2 with access-site wound dehiscence, and a case of pneumonia. Median hospital stay was 20 days (range 7–60) and median intensive care unit stay was 2.5 days (range 0–9). Over a mean 26-month follow-up (range 1–60), one unrelated death occurred. Reintervention was required in 1 patient due to progression of an aneurysm of the right iliac artery. Conclusion: Retrograde target vessel access in F/B-EVAR is a feasible bailout procedure when antegrade cannulation fails. Secondary technical success is high, but the procedure is associated with higher perioperative morbidity and longer hospital stay.

Open vs. endovascular repair of abdominal aortic aneurysm: a comparative analysis

Context:Abdominal aortic aneurysm (AAA) is a condition that is usually asymptomatic, but potentially fatal, and has a prevalence in men over 60 years old ranging from 4.3% to 8%. There are two treatment options available: open surgery (OS) and endovascular treatment (ET).Objective:To compare the results of repairs conducted using these two treatment methods from 2008 to 2013 in a tertiary hospital.Methods:A retrospective analysis comparing 119 patients treated with OS and 219 patients who underwent ET for AAA repair.Results:The ET group was older (71.3 vs. 68.2 years; p<0.001) and had a higher rate of coronary disease (44.7% vs. 27.7%; p=0.002) and a lower ejection fraction (57.6% vs. 64.3%; p<0.001); in turn, the OS group had more chronic obstructive pulmonary disease (16.0% vs. 5.9%; p=0.004) and a smaller proximal infrarenal neck (15.5 mm vs. 23.0 mm; p<0.001). However, there was no difference in ASA classification (American Society of Anesthesiology) (p=0.36). The ET group had less intraoperative bleeding (171 mL vs. 729 mL; p<0.001) and required fewer blood transfusions (11.9% vs. 73.1% p<0.001), and spent shorter stays in both ICU (2.4 vs. 3.5 days; p=0.002) and hospital (5.8 vs. 10.3 days; p<0.001). Thirty-day mortality was similar (OS 5.0% vs. ET 4.1%; p=0.78) and there was also no difference in postoperative complications. The average cost of ET was higher (R$34,277.76 vs. R$4,778.60; p<0.001).Conclusions:Rates of morbidity and mortality were similar, although ET was associated with less bleeding, fewer transfusions and shorter hospital stays, but was more expensive.

Open and endovascular repair of juxtarenal abdominal aortic aneurysms: a systematic review

This systematic review focuses on the 30-day mortality associated with open surgery and fenestrated endografts for short-necked (<15 mm) juxtarenal abdominal aortic aneurysms. A search for studies published in English and indexed in the PubMed and Medline electronic databases from 2002 to 2012 was performed, using "juxtarenal abdominal aortic aneurysm" and "treatment" as the main keywords. Among the 110 potentially relevant studies that were initially identified, eight were in accordance with the inclusion criteria in the analysis. Similar outcomes for open and endovascular repair were observed for 30-day mortality. No differences were observed regarding the secondary outcomes (duration of surgery, hospital stay, postoperative renal dysfunction and late mortality), except that the late mortality rate was significantly higher for the patients treated with open repair after a median follow-up of 24 months. Fenestrated endografting is a viable alternative to conventional surgery in juxtarenal abdominal aortic aneurysms with a proximal neck <15 mm.

Abdominal aortic aneurysm: Treatment options, image visualizations and follow-up procedures

Abdominal aortic aneurysm is a common vascular disease that affects elderly population. Open surgical repair is regarded as the gold standard technique for treatment of abdominal aortic aneurysm, however, endovascular aneurysm repair has rapidly expanded since its first introduction in 1990s. As a less invasive technique, endovascular aneurysm repair has been confirmed to be an effective alternative to open surgical repair, especially in patients with co-morbid conditions. Computed tomography (CT) angiography is currently the preferred imaging modality for both preoperative planning and post-operative follow-up. 2D CT images are complemented by a number of 3D reconstructions which enhance the diagnostic applications of CT angiography in both planning and follow-up of endovascular repair. CT has the disadvantage of high cummulative radiation dose, of particular concern in younger patients, since patients require regular imaging follow-ups after endovascular repair, thus, exposing patients to repeated radiation exposure for life. There is a trend to change from CT to ultrasound surveillance of endovascular aneurysm repair. Medical image visualizations demonstrate excellent morphological assessment of aneurysm and stent-grafts, but fail to provide hemodynamic changes caused by the complex stent-graft device that is implanted into the aorta. This article reviews the treatment options of abdominal aortic aneurysm, various image visualization tools, and follow-up procedures with use of different modalities including both imaging and computational fluid dynamics methods. Future directions to improve treatment outcomes in the follow-up of endovascular aneurysm repair are outlined.

Endovascular management of acute bleeding following recent and late open abdominal aortic aneurysm repair

Open repair of abdominal aortic aneurysm is still considered the gold standard against which endovascular repair is measured. We describe two cases of open repair complicated by bleeding where endovascular treatment proved to be life-saving.