Off-the-Shelf Fenestrated Endografts: A Realistic Option for More Than 70% of Patients With Juxtarenal Aneurysms

Urgent endovascular repair of juxtarenal/pararenal aneurysm by off-the-shelf multibranched endograft

OBJECTIVE

To report outcomes of urgent juxtarenal/pararenal aneurysms (J/P-AAAs) managed by off-the-shelf multibranched thoracoabdominal endografts (Cook, T-branch).

METHODS

In this observational, multicenter, retrospective study, patients with J/P-AAAs treated by urgent endovascular repair by T-branch in 23 European aortic centers, from 2013 to 2023, were analyzed. Contained J/P-AAAs rupture, presence of related symptoms, and aneurysm diameter of >70 mm were considered as indication for urgent repair. Technical success (TS), spinal cord ischemia (SCI), and 30-day/hospital mortality were assessed as early outcomes. Survival, freedom from reinterventions, and target artery instability (TAI) were evaluated during follow-up.

RESULTS

Overall, 197 patients (J-AAAs, n = 64 [33%]; P-AAAs, n = 95 [48%]; previous failed endovascular aneurysm repair (EVAR), n = 38 [19%]) were analyzed. The mean age and aneurysm diameter was 75 ± 8 years and 76 ± 4 mm, respectively. The American Society of Anesthesiologists score was 3 and 4 in 118 (60%) and 79 (40%) patients. Rupture, symptoms, and diameter of >70 mm were present in 51 (26%), 110 (56%), and 53 (27%) patients, respectively. An adjunctive proximal thoracic endograft was used in 28 cases (14%). The mean aortic coverage between the upper portion of the endograft and the lowest renal artery was 154 ± 49 mm. Single-stage repair and cerebrospinal fluid drainage were reported in 144 (73%) and 53 (27%) cases, respectively. TS was achieved in 182 (92%) cases (rupture, 84% vs no rupture, 95%; P = .02). Failures consist of TA loss (11 [6%]: renal artery, 9; celiac trunk, 2), type I to III endoleaks (2 [1%]), and 24-h mortality (2 [1%]). Rupture was a risk factor for technical failure (P = .02; odds ratio [OR], 3.8; 95% confidence interval [CI], 1.1-12.1). Overall, 15 patients (8%) had persistent SCI (rupture, 14% vs no rupture, 5%) with 11 (6%) , of paraplegia (rupture, 10% vs no rupture, 5%; P = .001). Rupture (P = .04; OR, 3.1; 95% CI, 1.1-8.9) and adjunctive proximal thoracic endograft (P = .01; OR, 4.1; 95% CI, 1.3-12.9) were risk-factors for SCI. Twenty-two patients (11%) died within 30 days or during a prolonged hospitalization. Previous failed EVAR (P = .04; OR, 3.6; 95% CI, 1.1-12.3), paraplegia (P < .001; OR, 9.9; 95% CI, 1.6-62.2) and postoperative mesenteric complications (P = .03; OR, 10.4; 95% CI, 1.2-93.3), as well as cardiac (P = .03; OR, 8.2; 95% CI, 2.0-33.0) and respiratory (P < .001; OR, 10.1; 95% CI, 2.9-35.2) morbidities were associated with 30-day/hospital mortality. The mean follow-up was 19 ± 5 months. The estimated 3-year survival and freedom from reinterventions was 58% and 77%, respectively. TAI occurred in 27 patients (14%) (occlusion, 15; endoleak, 14) with an estimated 3-year freedom from TAI of 72%.

CONCLUSIONS

Urgent repair of J/P-AAAs by T-branch is feasible and effective with satisfactory TS and 30-day/hospital mortality in high-risk patients. However, extensive aortic coverage is necessary, leading to a non-negligible SCI rate, especially in case of aortic rupture or when adjunctive thoracic endografts are necessary. Previous failed EVAR and postoperative mesenteric complications, as well as cardiac and respiratory morbidities were associated with 30-day/hospital mortality and should be subjected to more research for the purposes of improving outcomes.

Endovascular Abdominal Aortic Aneurysm Repair: Overview of Current Guidance, Strategies, and New Technologies, Perspectives from the United Kingdom

Endovascular aortic aneurysm repair has changed the management of patients affected by this condition, offering a minimally invasive solution with satisfactory outcomes. Constant evolution of this technology has expanded the use of endovascular devices to more complex cases. The purpose of this review article is to describe the current strategies, guidance, and technologies in this field, with a particular focus on practices in the United Kingdom.

Physician-modified fenestrated endograft for postdissection thoracoabdominal aortic aneurysm following provisional extension to induce complete attachment and renal artery stenting

We have described a patient with a history of type A-11 dissection repair, who subsequently underwent thoracic endovascular aortic repair with distal bare metal dissection stents (provisional extension to induce complete attachment) and renal artery stenting for malperfusion. During the next 3 years, the thoracoabdominal aorta had continued to enlarge to 6.9 cm, despite false lumen embolization and thoracic endovascular aortic repair extension. Given the continued aortic enlargement, physician-modified fenestrated endovascular aortic repair was performed within the prior aortic and renal stents with successful aneurysm sealing. The results from the present case have illustrated that continued aneurysmal degeneration can occur after provisional extension to induce complete attachment and that subsequent physician-modified fenestrated endovascular aortic repair is feasible.

Outcomes of off-the-shelf multibranched stent grafts with intentional occlusion of directional branches using endovascular plugs during endovascular repair of complex aortic aneurysms

OBJECTIVE

To evaluate the technique and outcomes of intentional occlusion of directional branches (DBs) using endovascular plugs during branched endovascular aortic repair using off-the-shelf Zenith t-Branch thoracoabdominal (TAAA) stent grafts.

METHODS

We reviewed the clinical data and outcomes of all consecutive patients treated by branched endovascular aortic repair using off-the-shelf Zenith t-Branch TAAA stent-graft (Cook Medical, Bloomington, Ind) in seven academic centers from 2013 to 2019. All patients had at least one DB intentionally occluded using extension of the branch with balloon or self-expandable covered stent, followed by placement of endovascular plugs. Intentional occlusion was indicated in patients with variations in the normal four-vessel renal-mesenteric anatomy, pre-existing dialysis, or in those who failed catheterization of a target vessel. End points were 30-day/in-hospital mortality, major adverse events, secondary interventions, target artery (TA) patency, TA instability, and patient survival.

RESULTS

There were 100 patients, 65 male and 35 female, with median age of 71 years (interquartile range [IQR], 66-75 years). Of these, 31 patients (31%) had urgent/emergent operations for symptomatic/contained ruptured aneurysms. The median aneurysm diameter was 72 mm (IQR, 61-85 mm). A total of 290 renal-mesenteric arteries were incorporated with a median of three (IQR, 3-3) vessels/patient. Indications for DB occlusion were less than four suitable renal-mesenteric targets in 84 patients or pre-existing dialysis and inability to catheterize a target vessel in eight patients each. There were 110 DBs occluded by vascular plugs, including 48 celiac axis, one superior mesenteric artery, and 61 renal DBs. Thirty-day/in-hospital mortality was 10%, including 9% for elective and 13% for urgent/emergent procedures. Major adverse events occurred in 44 patients (44%), including acute kidney injury in 19 patients (19%), estimated blood loss >1 L in 12 patients (12%), respiratory failure and new onset dialysis in six patients (6%) each, bowel ischemia in five patients (5%), and myocardial infarction and paraplegia in two patients (2%) each. The median follow-up was 5 months (range, 1-13 months). Eighteen patients (18%) required secondary interventions, none for problems related to the occluded DB. There were no endoleaks related to the occluded DB. At 2 years, primary and secondary patency and freedom from TA instability were 93% ± 3%, 97% ± 2%, and 91% ± 4%, respectively. Freedom from secondary interventions and patient survival were 75% ± 6% and 63% ± 7%, respectively.

CONCLUSIONS

Intentional occlusion of DBs using endovascular plugs allows versatile use of a four-vessel off-the-shelf multi-branched TAAA stent graft in patients with variations in the normal renal and mesenteric anatomy or when technical difficulties prevent successful target vessel stenting. There were no endoleaks or secondary interventions associated with the occluded DB.

Exclusion of complex aortic aneurysm with chimney endovascular aortic repair is applicable in a minority of patients treated with fenestrated endografts

OBJECTIVES

The Medtronic Endurant II stent graft has recently received Conformité Européenne (CE) approval for the use in chimney endovascular aortic repair (ChEVAR) for the treatment for juxtarenal aortic aneurysms. The aim of this study was to assess the percentage of patients treated by fenestrated endovascular repair who would have been alternatively suitable for the treatment by the CE approved Medtronic ChEVAR.

METHODS

Preoperative computed tomography scans of 100 patients who underwent fenestrated endovascular aortic repair (FEVAR) between April 2013 and February 2017 were retrospectively assessed for the applicability of the ChEVAR technique according to the Medtronic instructions for use. Eligibility criteria included an aortic neck diameter of 19-30 mm, a minimum infrarenal neck length of 2 mm, a total proximal sealing zone of at least 15 mm, thrombus in the aortic neck in ˂25% of the circumference, and maximum aortic angulations of 60° in the infrarenal, 45° in the suprarenal segment and ˂45° above the superior mesenteric artery.

RESULTS

According to CE-approved inclusion criteria, 19 individuals (19%) would have been eligible for ChEVAR. In 81 patients, at least 1 measure was found outside instructions for use: (i) excluding factor was detected in 26 patients, (ii) incongruous measures in 28 patients and in 27 patients, 3-5 measures were outside the instructions for use. The most frequently identified excluding factor was an insufficient infrarenal neck at ˂2 mm length (n = 63; 63%).

CONCLUSIONS

Patients with juxta- or pararenal aneurysm treated by FEVAR are in 19% of the cases alternatively suitable for the treatment by ChEVAR within CE-approved instructions for use. While ChEVAR is suitable in many emergency cases, FEVAR offers a broader applicability in an elective setting.

Physician Modified Low Profile Endograft for Endovascular Repair of Juxtarenal Abdominal Aortic Aneurysms in Patients with Small Access Vessels

Introduction

Urgent or emergency treatment of patients with abdominal aortic aneurysms that are anatomically unsuitable for conventional repair because of short proximal necks, small diameters and access vessel calcification, and high risk for open repair can be performed with commercially available branched or fenestrated aortic endografts or physician modified stent grafts.

Report

A technique is described for modification and successful implantation of a commercially available standard aortic stent graft with a low profile main body in two patients at high risk for open repair, with small access vessels and requiring uni- or bilateral renal artery fenestration for juxtarenal aneurysm repair.

Discussion

Based on two case experiences, the use of physician modified off the shelf endografts appears to be a feasible and effective alternative to fenestrated endovascular repair in patients with juxtarenal abdominal aortic aneurysms at high risk for open surgical repair. Studies comparing effectiveness of the different options, including chimney/snorkel technique and debranching, are warranted.

Five Year Results of Off the Shelf Fenestrated Endografts for Elective and Emergency Repair of Juxtarenal Abdominal Aortic Aneurysm

OBJECTIVE

Fenestrated endovascular aneurysm repair (FEVAR) is a well established treatment for complex abdominal aortic aneurysms (AAAs). FEVAR with custom made devices (CMDs) has limitations in both the emergency and elective settings due to time consuming manufacture. "Off the shelf" (OTS) fenestrated stent grafts are a potential solution. The primary goal was to evaluate the five year outcome of the COOK Zenith p-Branch OTS device at a single centre.

METHODS

Patients with juxtarenal AAA meeting the inclusion criteria for the COOK Zenith p-Branch device were enrolled in a prospective, non-randomised, non-comparative trial from July 2012 to September 2015. Demographic, anatomical, procedure related, and five year follow up data were collected, analysed, and adjudicated by a core laboratory. The primary aims were to assess intervention free survival and overall survival at five years.

RESULTS

Twenty-three patients were treated and 21 completed follow up. Mean time to p-Branch implantation after patient presentation was 28 hours (range 0-122 hours) in emergency cases and 67 days (range 20-112 days) in elective cases. Median procedure time was 283 minutes (range 161-475 minutes) and technical success was 91%. Mean follow up was 45 months (standard deviation ± 24.4 months). The most common adverse events were renal injuries. Primary target vessel patency was 96.4% and 94.0% after one and five years respectively. Mean time to first re-intervention was 469 days (range 0-1 567 days). Survival during the follow up period was 76%, with no aneurysm related deaths.

CONCLUSION

FEVAR with the COOK Zenith p-Branch device is safe and effective for juxtarenal AAA in a selected patient population, in both elective and emergency settings. Long term outcomes are acceptable although inferior to CMDs. Mid and long term outcomes emphasise the p-Branch as a possible endovascular treatment for juxtarenal aortic pathology where CMD is not an option. Further innovation to address target vessel complications is needed, as these seem more prevalent than after repair with CMDs.

The role of fEVAR, chEVAR and open repair in treatment of juxtarenal aneurysms: a systematic review

INTRODUCTION

Open repair (OR), fenestrated endovascular aneurysm repair (fEVAR) and endovascular exclusion using parallel graft (chEVAR) are complementary procedures used for treatment of juxtarenal abdominal aortic aneurysm (jrAAA). The aim of our study was to assess available literature and analyze dispersion of OR, fEVAR and chEVAR procedures among reported papers related to treatment of jrAAA.

EVIDENCE ACQUISITION

The PubMed database was systematically searched using predefined strategy and key words related to treatment of jrAAA on September 28th, 2019. Studies were assessed for eligibility using the inclusion and exclusion criteria with at least five patients treated with at least one of the procedures while systematic reviews, meta-analysis, reviews, comments, editorials and letters were excluded as well as studies without clear classification of the location of the aneurysm, studies not specifying the number of patients treated with each of the techniques or not discriminated between aortic pathologies (juxtarenal, paravisceral and thoracoabdominal), hybrid procedures, endoanchors or with branched stent-graft.

EVIDENCE SYNTHESIS

Overall, 1533 papers were identified while papers that met inclusion criteria were either representing experience of single institution (87 papers) or from multicenter studies (6 papers), national or international registries (18 papers). In the period between January 1977 and December 2017, treatment of 5664 patients with jrAAA was reported in 87 papers as a single institution report. Out of them 2531 (45%) were treated with OR, 2592 (46%) with fEVAR and 541 (9%) with chEVAR. Out of 29 institutions reporting OR, there were 11 (37.9%) with more than 100 treated patients while 21 (41.1%) out of 51 institutions that reported more than 50 jrAAA treated with fEVAR. Only four institutions reported results of all three treatment modalities.

CONCLUSIONS

Based on the results reported in the literature, regardless of its complexity and costs, fEVAR for jrAAA has been accepted in substantial number of hospitals worldwide, while number of reported procedures is reaching OR.

Results from a prospective multicenter feasibility study of Zenith p-Branch stent graft

OBJECTIVE

To evaluate the Cook Zenith p-Branch stent graft (William A. Cook Australia, Brisbane, Queensland, Australia) for the treatment of patients with asymptomatic juxtarenal or pararenal abdominal aortic aneurysms in a prospective, nonrandomized, multicenter, feasibility study conducted in the United States.

METHODS

The off-the-shelf p-Branch endograft incorporates a celiac scallop, superior mesenteric artery (SMA) fenestration, and two conical-shaped pivot renal fenestrations. Patients were eligible if the aneurysm did not extend above the distal margin of the SMA and the anatomy of renal and visceral arteries were compatible with one of the two p-Branch configurations (configuration A, renal fenestrations at the same longitudinal position; configuration B, offset renal fenestration).

RESULTS

A total of 30 patients (93% men; mean age, 73 years; mean aneurysm diameter, 64.7 ± 11.4 mm) were enrolled from January 2013 to June 2015. The mean follow-up period was 28.7 ± 12.5 months (as of October 2017). The technical success rate was 93% (28/30), with technical failure occurring in the first two study cases (device deliberately repositioned below the renal arteries because of difficulty in cannulating the renal arteries in one and an inability to place a renal stent in the other; both patients survived the procedure and withdrew from the study before the 12-month follow-up visit). No additional technical failures occurred after these first two cases, when an updated physician training and proctoring program was implemented. No 30-day mortality occurred. Of the remaining 28 patients, three died during the follow-up period; none within 30 days and none related to the device or procedure as determined by Clinical Events Committee adjudication. No treated aneurysm ruptures, conversion, or core laboratory-reported migration, or stent fracture were reported. The primary renal artery patency (interval to occlusion or reintervention for stenosis) rate was 88.6% ± 4.4% at 1 and 2 years. Two patients (7%) developed renal insufficiency secondary to a right renal artery stenosis in one patient and progression of chronic renal insufficiency in one patient. No patient required dialysis or developed mesenteric ischemia. Of the 28 patients, nine (32%) had undergone 13 secondary interventions for renal artery occlusion (n = 2), SMA occlusion (n = 1), renal or SMA stenosis (5 interventions in 4 patients), renal stent kinking (n = 1), lower extremity claudication (n = 2 in the same patient), type III endoleak between the p-Branch and renal stent (n = 1), and type II endoleak (n = 1).

CONCLUSIONS

These early and intermediate results, which incorporated physician learning curves, support the safety and feasibility of the off-the-shelf Zenith p-Branch device. Follow-up examinations through 5 years will continue to assess the long-term results.

Patient and operating room staff radiation dose during fenestrated/branched endovascular aneurysm repair using premanufactured devices

INTRODUCTION

Fenestrated endovascular aneurysm repair (FEVAR) is the highest radiation dose procedure performed by vascular surgeons. We sought to characterize the radiation dose to patients and staff during FEVAR procedures with different premanufactured devices.

METHODS

A single-center prospective study of FEVARs was performed over 24 months. Three FEVAR devices were included: off-the-shelf (OTS; t-Branch, p-Branch), Zenith Fenestrated (ZFen), and investigational custom-made devices (CMDs). Radiation doses to the surgeon, trainee, anesthesiologist, and scrub/circulating nurses were measured using a personal dosimetry system (DoseAware, Philips Healthcare, Amsterdam, The Netherlands). Procedure type, patient body mass index (BMI), reference air kerma (RAK), and kerma area product (KAP) were recorded. RAK and KAP were corrected for BMI based on an exponential fit of fluoroscopy dose rate and the dose per radiographic frame. Operator dose was corrected for BMI by the ratio of corrected to actual KAP. A one-sided Wilcox rank-sum test was used to compare personnel radiation doses, RAKs, and KAPs between procedure types. Statistical significance was set at P ≤ .05.

RESULTS

There were 80 FEVARs performed by a single surgeon on a Philips Allura XperFD20 fluoroscopy system equipped with Clarity technology. Average BMI was 27 kg/m². Sixty CMDs (36 four-, 21 three-, and 3 two-vessel fenestrations), 11 ZFens (8 three- and 3 two-vessel fenestrations), and 9 OTS devices (4 p-Branch, 5 t-Branch) were included. ZFens had significantly lower patient (1800 mGy vs 2950 mGy; P = .004), operator (120 μSv vs 370 μSv; P = .004), assistant (60 μSv vs 210 μSv; P = .003), circulator (10 μSv vs 30 μSv; P = .049), and scrub nurse dose (10 μSv vs 40 μSv; P = .02) compared with CMDs. OTS devices had significantly lower operator (220 μSv vs 370 μSv; P = .04), assistant (110 μSv vs 210 μSv; P = .02), and circulator doses (4 μSv vs 30 μSv; P = .001) compared with CMDs. Four-vessel fenestrated devices had significantly higher patient dose (3020 mGy) compared with three-vessel FEVARs (2670 mGy; P = .03) and two-vessel FEVARs (1600 mGy; P = .0007), and significantly higher operator dose (440 μSv) compared with three-vessel FEVARs (170 μSv; P = .0005). Patient dose was lowest with ZFens. Operating room personnel dose was lower with ZFens and OTS devices compared with CMDs. Four-vessel fenestrations required significantly more radiation compared with those involving three-vessel fenestrations; however, the dose increase was only 12% and should not preclude operators from extending coverage, if anatomically required.

CONCLUSIONS

Overall, patient and personnel radiation doses during FEVAR with all devices were within acceptable limits and lower in our series than previously reported.

Anatomical Suitability of the Zenith Off-the-Shelf (p-Branch) Endograft in Juxtarenal Aortic Aneurysms Previously Treated Using the Chimney Technique

Purpose:

To examine the suitability of the Zenith off-the-shelf (p-branch) endograft in patients with juxta- or pararenal abdominal aortic aneurysms (J/PRAA) previously treated with endovascular aneurysm repair incorporating the chimney technique (chEVAR).

Methods:

Between January 2012 and December 2014, high-resolution computed tomography angiograms and clinical data from 50 patients (mean age 79 years; 45 men) with J/PRAAs treated with chEVAR were retrospectively reviewed. Primary anatomical suitability was evaluated according to the Investigational Device Exemption protocol for the Zenith p-branch endograft in a dedicated 3-dimensional vascular workstation. Secondary suitability was defined as any additional intervention needed to overcome adverse anatomical conditions at the access vessels. The Zenith p-branch endograft is available in 2 configurations (A and B), with the main difference being the distance between the superior mesenteric artery (SMA) and the renal fenestrations.

Results:

The p-branch endograft showed a primary suitability of 54% (n=27). Each configuration was suitable in 18 (36%) patients. Main anatomical limitations were the clock position of the left renal artery (LRA; n=7, 14%), the distance between the SMA and LRA (A: n=16, 32%; B: n=16, 32%), and significantly narrowed or calcified iliac arteries. If additional interventions at the access vessels were employed, a secondary suitability of 64% (n=32) could be achieved.

Conclusion:

In this specific group of patients treated with chEVAR, the Zenith p-branch system would be suitable in about half of the patients, which could be raised to two-thirds with ancillary access vessel procedures. A prospective clinical study is warranted to evaluate these results.

Computer-assisted study of the axial orientation and distances between renovisceral arteries ostia

PURPOSE

Endovascular navigation in aortic, renal and visceral procedures are based on precise knowledge of arterial anatomy. Our aim was to define the anatomical localization of the ostia of renovisceral arteries and their distribution to establish anatomical landmarks for endovascular catheterization.

METHODS

Computer-assisted measurements performed on 55 CT scans and patients features (age, sex, aortic diameter) were analyzed. p values <0.05 were considered statistically significant.

RESULTS

The mean axial angulation of CeT and the SMA origin was 21.8° ± 10.1° and 9.9° ± 10.5°, respectively. The ostia were located on the left anterior edge of the aorta in 96 % of cases for the CeT and 73 % for the SMA. CeT and SMA angles followed Gaussian distribution. Left renal artery (LRA) rose at 96° ± 15° and in 67 % of cases on the left posterior edge. The right renal artery (RRA) rose at -62° ± 16.5° and in 98 % of cases on the right anterior edge of the aorta. RRA angle measurements and cranio-caudal RRA-LRA distance measurements did not follow Gaussian distribution. The mean distances between the CeT and the SMA, LRA, and RRA were 16.7 ± 5.0, 30.7 ± 7.9 and 30.5 ± 7.7 mm, respectively. CeT-SMA distance showed correlation with age and aortic diameter (p = 0.03). CeT-LRA distance showed correlation with age (p = 0.04). The mean distance between the renal ostia was 3.75 ± 0.21 mm. The RRA ostium was higher than the LRA ostium in 52 % of cases. RRA and LRA origins were located at the same level in 7 % of cases.

CONCLUSION

Our results illustrate aortic elongation with ageing and high anatomical variability of renal arteries. Our findings are complementary to anatomical features previously published and might contribute to enhance endovascular procedures safety and efficacy for vascular surgeons and interventional radiologists.

'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.

Use of the Off-the-Shelf t-Branch Device to Treat an Acute Type Ia Endoleak in a Symptomatic Juxtarenal Abdominal Aortic Aneurysm

PURPOSE

To report the use of the off-the-shelf Zenith t-Branch Thoracoabdominal Endovascular Graft for the treatment of a symptomatic acute type Ia endoleak subsequent to previous infrarenal bifurcated endovascular aneurysm repair.

CASE REPORT

A 72-year-old man presented 4 years after implantation of an Anaconda stent-graft with sac expansion and type II endoleak, which was treated over the next 18 months with repeated coil and glue embolization of the leak and sac. Six months after the last attempt, imaging disclosed a new type Ia endoleak. Sac enlargement became symptomatic, and emergent treatment was performed using the off-the-shelf Zenith b-Branch device. The 4 visceral arteries were bridged with Fluency stent-grafts. The Anaconda stent-graft precluded the use of a standard Zenith universal distal body bifurcated device below the t-Branch graft, so a reversed tapered 16×20×82-mm iliac limb was placed to bridge the t-Branch to the larger Anaconda limb; the smaller 12-mm contralateral Anaconda limb was occluded. The procedure was concluded with a femorofemoral bypass. At 10 months after the procedure, the patient is well; the sac diameter has decreased, and there is no endoleak on imaging.

CONCLUSION

The multibranched Zenith t-branch device may be useful in treating proximal endoleaks in bifurcated stent-grafts.

Systematic Review of Off-the-Shelf or Physician-Modified Fenestrated and Branched Endografts

Purpose: To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and physician-modified stent-grafts (PMSGs) for the treatment of complex abdominal aortic aneurysms. Methods: A systematic search of the MEDLINE database via PubMed from January 2001 through March 2015 retrieved 23 relevant articles evaluating the clinical outcomes following the management of patients with pararenal or thoracoabdominal aortic aneurysms. The 15 articles on PMSGs and 8 on OSFGs contained data on 308 patients (mean age 72.93±2.89 years; 213 men). The safety endpoint was major adverse events; the efficacy outcome measure was clinical treatment success (aneurysm exclusion without type I/III endoleak, permanent paralysis, long-term dialysis, or unresolved major complications). Extracted outcome data were pooled and compared between groups; data are given as the pooled proportions and 95% confidence interval (CI). Clinical data are presented as the weighted mean. Results: Of the 308 patients analyzed, almost one third were operated on an emergency basis. The mean aneurysm diameters were 75.9±17.3 mm (range 56–115) for the PMSGs and 68.1±13.7 mm (range 60–100) for the OSFGs. A total of 936 renal and visceral vessels were targeted. Major adverse events (safety) occurred in 24 (12.8%) PMSG patients (95% CI 8.6% to 18.7%) and in 9 (7.4%) OSFG patients (95% CI 3.7% to 14%). Clinical treatment success (efficacy) was observed in 171/187 (91.4%) PMSG patients (95% CI 86.2% to 94.9%) and in 115/121 (95%) OSFG patients (95% CI 89.1% to 98.0%). Corresponding cumulative 30-day target vessel and branch stent perfusion rates were 97.2% (95% CI 95.1% to 98.4%) and 97.6% (95% CI 95.5% to 98.8%) for the PMSG group and 99.6% (95% CI 98.3% to 99.9%) and 98.4% (95% CI 96.5% to 99.4%) for the OSFG group. Six (3.2%) deaths occurred in the PMSG group only; 2 (1.1%) were aneurysm related. Overall branch patency was recorded in 443/458 (96.7%) and in 468/478 (97.9%) of target vessels in the PMSG and OSFG groups, respectively. Conclusion: Off-the-shelf and physician-modified technology seems effective and safe, in both the elective and acute settings, for the treatment of complex aortic aneurysms. Future research within a randomized trial should investigate the true limitations of these devices.

Suitability of the Zenith p-Branch Standard Fenestrated Endovascular Graft for Treatment of Ruptured Abdominal Aortic Aneurysms

Purpose: To evaluate the anatomic suitability of the Zenith pivot branch (p-branch) fenestrated device in ruptured abdominal aortic aneurysms (rAAA). Methods: Contrast-enhanced computed tomography (CT) images of 206 patients (mean age 75±8 years; 175 men) with rAAA were evaluated in a dedicated 3-dimensional vascular workstation. All aneurysms found unsuitable for standard infrarenal repair were evaluated for Zenith p-branch suitability according to the Investigational Device Exemption protocol for both device configurations (A, pivot fenestrations at the same level; B, right renal fenestration located more cranially). Results: The suitability of the p-branch (A or B configuration) for short neck aneurysms (<15 mm; n=89) was 49%; of the 26 different combinations of exclusion criteria, a mismatch between a renal artery takeoff and the positioning of the corresponding fenestration was the most common. For juxta- and pararenal aneurysms (neck length <10 mm; n=66), suitability was 48%. Suitability assessed by target vessel positioning only (excluding all other limiting factors) was 58% for short neck aneurysms (n=52) and 55% for juxta- and pararenal aneurysms (n=36). Conclusion: Approximately half of patients with short neck rAAAs would be suitable for the Zenith p-branch fenestrated device according to the instructions for use. In almost 60%, the pivot fenestrations can accommodate the corresponding target vessels. More studies are needed to confirm these findings.

The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms

PURPOSE

This study investigated the impact of the variant angulations on the values and distribution of wall shear stress on the renal branches and the mating vessels of a pivotal fenestrated design.

METHODS

An idealized endograft model of two renal branches was computationally reconstructed with variable angulations of the left renal branch. These ranged from the 1:30' to 3:30' o'clock position, corresponding from 45° to 105° with increments of 15°. A fluid-structure-interaction analysis was performed to estimate the wall shear stress.

RESULTS

The proximal part of the renal branch preserved quite constant wall shear stress. The transition zone between its distal end and the renal artery showed the highest values compared to the proximal and middle segments, ranging from 8.9 to 12.4 Pa. The lowest stress values presented at 90° whereas the highest at 45°. The post-mating arterial segment showed constantly low stress values regardless of the pivotal branch angle (6.3 to 6.6 Pa). The 45° configuration showed a distribution of the highest stress posteriorly whereas the 105°-angulation anteriorly.

CONCLUSIONS

The variant horizontal branch orientation influences the wall shear stress distribution across its length and affects its values only at its transition with the mating vessel. These findings and their potential association with adverse effects deserve further clinical validation.

"Off-the-shelf" devices for complex aortic aneurysm repair

BACKGROUND

Fenestrated devices currently require a 3- to 4-week manufacturing period before implantation; as such, there have been efforts to develop "off-the-shelf" (OTS) devices to reduce the time before definitive treatment can be accomplished. We examined all patients treated for complex aortic problems at our institution during the past 12 months to evaluate the suitability and early outcomes of the OTS devices vs commercially available endovascular options.

METHODS

Between July 2012 and September 2013, patients undergoing aortic aneurysm repair were extracted from a prospectively managed aortic database. Two OTS devices, the Cook (Bloomington, Ind) p-Branch and the Endologix (Irvine, Calif) Ventana device, were being evaluated through clinical trials during this time frame. The custom Cook Zenith fenestrated endovascular (ZFEN) device was also available and approved by the U.S. Food and Drug Administration (FDA) during the study period.

RESULTS

Of 224 aortic aneurysms treated at our institution during this period, there were a total of 85 patients with type IV thoracoabdominal aneurysms including juxtarenal aneurysms. Only 23 patients (27%) met anatomic criteria for OTS devices, with 16 patients having these investigational devices implanted. The major exclusion criterion for the p-Branch device was renal axial or circumferential position; the limiting factor for Ventana was infrasuperior mesenteric artery neck length restriction. Five of the patients who would have fit criteria for an OTS device had an FDA-approved (ZFEN) device implanted instead, and two patients opted for open repair as a result of follow-up requirements. An additional 25 patients received custom-designed (ZFEN) devices (n = 30; 35%), whereas 37 (44%) others did not meet criteria for any available endovascular device and were repaired with alternative management strategies. The mean age and maximal aortic diameter of the two cohorts (OTS and ZFEN) were 71.8 years and 72.7 years (P = NS) and 61.3 mm and 58.5 mm (P = NS), respectively. Technical success was 100%, with an overall 30-day mortality of 2.1% (n = 1, ZFEN). Major complications occurred in eight patients (17%; two OTS, six ZFEN).

CONCLUSIONS

Whereas OTS device strategies will reduce the waiting times for patients with complex aortic aneurysmal disease, a significant number will still require custom-made device repair until additional device designs become available. Early experience with OTS devices does not demonstrate any significant renal risks; however, the treatment numbers are low and should be interpreted with caution until larger confirmatory studies are published. Further studies comparing the outcomes of these techniques are required to establish the best approach to handle endovascular repair of complex aortic aneurysm.

Preliminary results of Zenith Fenestrated abdominal aortic aneurysm endovascular grafts

BACKGROUND

Patients with juxtarenal aortic aneurysms who are unfit for open repair may be considered for fenestrated endovascular repair (fenEVAR). We report our initial experience with fenEVAR.

METHODS

We reviewed the data on all our patients receiving fenEVAR for juxtarenal aortic aneurysms.

RESULTS

Eight patients, average age 75 years, underwent fenEVAR. Endografts were designed from details obtained from preoperative computed tomography angiography. There were 6 grafts with superior mesenteric scallops and bilateral renal fenestrations, 1 with bilateral renal scallops, and 1 with a single renal fenestration. All patients survived 30 days. There was no renal failure requiring dialysis. At 10 weeks, 1 patient died from acute intestinal ischemia and multisystem organ failure, and another died from respiratory failure.

CONCLUSIONS

It is feasible to offer fenEVAR to patients who are poor candidates for open repair. However, these procedures are technically challenging. Early outcomes are less favorable than other aortic endovascular procedures.