Endovascular Repair of Abdominal Aortic Aneurysm Using a Pararenal Fenestrated Stent-Graft

Use of 3D Printing to Guide Creation of Fenestrations in Physician-Modified Stent-Grafts for Treatment of Thoracoabdominal Aortic Disease

Purpose: To summarize the experience and outcomes of total endovascular repair of thoracoabdominal aortic disease using 3-dimensional (3D) printed models to guide on-site creation of fenestrations in aortic stent-grafts. Materials and Methods: From April 2018 to March 2019, 34 patients (mean age 58±14 years; 24 men) with thoracoabdominal aortic disease were treated in our department. Nineteen patients had thoracoabdominal aortic dissection and 15 had thoracoabdominal aortic aneurysm. Preoperatively, a 3D printed model of the aorta was made according to computed tomography images. In the operating room, the main aortic stent-graft was completely released in the 3D printed model, and the position of each fenestration or branch was marked on the stent-graft. The fenestrations were then made using an electric pen. Wires were sewn to the edge of the fenestrations using nonabsorbable sutures. After customization, the aortic stent-graft was reloaded into the delivery sheath and deployed. Results: The printing process took ~5 hours (1 hour for image reconstruction, 3 hours for printing, and 1 hour for postprocessing). The physician-modified stent-grafts had a total of 107 fenestrations secured by 102 bridging stent-grafts, including 73 covered stents and 29 bare stents. The average procedure time was 5.6±1.2 hours, including a mean 1.3 hours for stent-graft customization. No renal insufficiency or paraplegia occurred. Two branch arteries were lost during the operation. One patient (3%) died 1 week after surgery from a retrograde dissection rupture. One patient developed a minor cerebral infarction postoperatively. The mean follow-up time was 8.5 months. There was 1 endoleak from a fenestration (coil embolized) and 4 distal ruptures of the aortic dissection (3 treated and 1 observed). Conclusion: Three-dimensional printing can be used to guide creation of fenestrated stent-grafts for the treatment of thoracoabdominal aortic diseases involving crucial branches. This technique appears to be more accurate than the traditional measurement method, with short-term follow-up demonstrating the safety and reliability of the method. However, further research and development are needed.

Imaging Obtained Up To 12 Months Preoperatively Is Adequate for Planning Fenestrated/Branched Endovascular Aortic Aneurysm Repair

OBJECTIVES

Patients referred for fenestrated/branched endovascular aortic repair (F/BEVAR) often present with a previous computed tomography angiogram (CTA), but it is unknown how recent the CTA must be to ensure accurate F/BEVAR planning. We sought to determine whether anatomic planning parameters change significantly between a CTA used for F/BEVAR planning and a CTA obtained 6 to 12 months prior.

METHODS

Two blinded observers reviewed preoperative CTAs from 21 patients who underwent F/BEVAR. Each patient had a "recent" scan obtained 0 to 6 months before F/BEVAR planning and a "prior" scan obtained 6 to 12 months before the "recent" CTA. Standard measurements included (1) target vessel separation distances, (2) target vessel origin clock position, and (3) proximal F/BEVAR device diameter. Clinically significant differences for target vessel separation distance, target vessel origin clock position, and proximal F/BEVAR device diameter were predefined as >5 mm, >30 minutes, and >4 mm, respectively. Differences between "recent"/"prior" CTA scans were examined by paired t test.

RESULTS

Mean time interval between paired "recent"/"prior" CTAs was 8.0 months (standard deviation: ±1.7). Mean difference in paired "recent"/"prior" target vessel distance (relative to celiac artery [CA]) was 2.6 mm for the superior mesenteric artery (SMA), 2.5 mm for the right renal artery (RRA), and 3.3 mm for the left renal artery (LRA). Of the 21 paired "recent"/"prior" CTAs, clinically significant differences were observed in 2, 4, and 2 patients for SMA, RRA, and LRA target vessel distance, respectively. Target vessel clock position (SMA reference at 12:00) varied by 12 minutes for the CA, 13 minutes for the RRA, and 15 minutes for the LRA. One paired "recent"/"prior" CTA was found to have a clinically significant difference for the LRA. No clinically significant differences were observed for proximal device diameter.

CONCLUSIONS

In patients who underwent successful F/BEVAR, measurement comparisons between CTAs obtained up to 1 year prior were minor and unlikely to yield clinically significant changes to F/BEVAR design.

Jotec E-Ventus BX Stent Graft Deployment in the FEVAR and Iliac Branch Device: Single Centre Experience

Objectives: To evaluate the outcomes of the E-ventus BX balloon-expandable stent graft system (Jotec, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) and the iliac branch device (IBD) of complex aneurysms.

Methods: This was a single centre retrospective analysis prospective study including all consecutive patients treated by FEVAR and the IBD performed with E-ventus BX stent grafts as bridging stents. Demographics of patients, the diameter and length of the bridging stent grafts, technical success, reinterventions, occlusions, post-operative events, and imaging (computed tomography [CT] scan and ultrasound) were prospectively collected in an electronic database. Follow-ups were performed with clinical assessment and a CT angiogram scan at four weeks after discharge followed by a duplex ultrasound every six months for two years and then a yearly duplex scan afterwards.

Results: Between June 2015 and October 2017, 40 consecutive patients (three females) were treated with custom made fenestrated endografts and the iliac branch device for complex aneurysms, using the E-Ventus BX stent graft. All 82 E-Ventus BX stent grafts were successfully delivered and deployed. There was no in-hospital mortality. The early bridging stents patency rate was 97.6% (80 out of 82). The two-target vessel post-operative occlusion was secondary to kink of the renal stents and failure for re-lining of the renal artery. Of the two patients, only one needed permanent dialysis. On the late follow-up (after 30 days), two other patients demonstrated a renal stent occlusion, with one treated successfully with re-lining of the stent and the other patient treated conservatively. Neither of them needed permanent dialysis. A follow-up was maintained for 36 patients until April 2018 with a median follow-up of 18 months. All bridging stents E-Ventus BX stent grafts remained patent (78 out of 82, 95.1%).

Conclusion: E-Ventus BX stent grafts used as bridging stents during FEVAR and the IBD are associated with favourable outcomes at the mid-term follow-up. Long-term follow-up is required to confirm these promising results.

Safety and Functionality of a Guidewire Fixator: Clinical Investigation of a New Endovascular Tool

Supplemental digital content is available in the text.

Objective

A new endovascular tool, the Liungman Guidewire Fixator, has been developed to simplify endovascular treatment in complex aortic aneurysms. The device has been extensively tested in bench models and animal trials. To verify the safety and functionality demonstrated in the porcine model, the device was tested in ten patients undergoing endovascular aortic repair (EVAR) or fenestrated endovascular aortic repair (f-EVAR) treatment for abdominal aortic aneurysm.

Methods

The Liungman Guidewire Fixator consists of a braided stent-like, cylindrical structure with conical ends and a central channel for a 0.035″ guidewire. When in use, it is slid along the guidewire and positioned in the target artery, where the Liungman Guidewire Fixator interacts with the arterial wall by anchoring the guidewire to the wall through a radial force. The Liungman Guidewire Fixator allows for uninterrupted blood flow passed the point of fixation. In this study, the Liungman Guidewire Fixator was tested in ten patients undergoing EVAR or f-EVAR treatment for abdominal aortic aneurysm. The device was deployed and retrieved crossover into the hypogastric artery, and the occurrence of thrombotic occlusion, arterial dissection, and vascular rupture or trauma was studied using angiography, as well as device ability to withstand guidewire tension.

Results

There were no instances of occlusion, dissection, or vascular trauma detected using angiography. In all cases, deployment and retrieval were successful, and the devices could withstand an applied tension of 3 N. In one instance, retrieval was challenging because of significant tortuosity, which was resolved by a coaxial catheterization.

Conclusions

Deployment was uneventful in all ten patients. Retrieval according to the intended instruction for use was performed in nine of the patients. In one patient, a coaxial catheterization was necessary. All devices withstood a retention force of 3 N.

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.

Endoluminal aortic grafting with renal and superior mesenteric artery incorporation by graft fenestration

PURPOSE

To explore the use of juxta- and suprarenal aortic segments for endograft fixation in abdominal aortic aneurysm (AAA) patients and to develop methods of graft implantation that use endograft fenestrations to preserve renal and visceral vessel perfusion.

METHODS

From August 1998 to May 2000, 13 AAA patients with unsuitable infrarenal aortic necks were treated with custom-designed endovascular grafts employing the juxta- and suprarenal aortic segments for proximal sealing. Flow to 33 renal and superior mesenteric arteries was maintained via graft fenestrations that were aligned by use of radiopaque graft markers. The fenestration-orifice interface for renal arteries was secured with modified balloon-expandable stents.

RESULTS

All fenestrated grafts were deployed as planned, and all target vessels (33/33) were preserved. Two patients did not receive any stents, one being the first in the series and another who had incorporation of a renal accessory artery only. Without the use of transgraft stenting, 5 renal arteries would have been occluded by the endograft or poorly perfused. Procedural success was 100%. No conversion to open operation or graft-related complications occurred. There was no primary endoleak in any patient by angiographic criteria. Two patients required additional surgical procedures related to access vessels. Periprocedural mortality at 30 days was nil. Follow-up ranging from 3 to 24 months on all patients has not demonstrated any proximal or distal endoleaks. One stented renal vessel has occluded; all other arteries remain patent at last examination.

CONCLUSIONS

This study has demonstrated the ability to successfully place a multifenestrated endoluminal graft in an aortic aneurysm using juxta- and suprarenal aortic segments to obtain a satisfactory seal. Stenting of the fenestration-renal ostium junction has helped to maintain renal patency.

An endovascular system for thoracoabdominal aortic aneurysm repair

PURPOSE

To describe a stent-graft system for endovascular repair of thoracoabdominal aortic aneurysm (TAAA) that preserves side branch perfusion.

TECHNIQUE

The modular endograft system includes 3 components. The primary stent-graft is custom-made from conventional graft fabric and Gianturco Z-stents. Covered nitinol Smart Stents are used for the visceral and renal extensions, and the distal extension is made from a modified Zenith system. With the supine patient under general anesthesia, the components are delivered sequentially through surgically exposed femoral and right brachial arteries in an operation that requires prolonged periods of magnified high-resolution imaging. This system was first used in a 76-year-old man with a contained rupture of a supraceliac ulcer and a large abdominal aortic aneurysm ending proximally at the celiac artery. The endograft was implanted successfully, but the patient developed paraplegia on day 2; imaging documented an excluded aneurysm and excellent flow through the endograft and all prosthetic branches.

DISCUSSION

Endovascular repair of TAAA appears to be feasible. If there are no serious, specific, unavoidable complications, the potential advantages are enormous.

Suprarenal mycotic aneurysm exclusion using a stent with a partial autologous covering

PURPOSE

To report a combined endovascular and open technique to manage a suprarenal mycotic aortic aneurysm using a stent-graft partially covered with a section of autologous artery.

METHODS AND RESULTS

A 50-year-old was hospitalized for staphylococcal septicemia and severe back pain. A previously diagnosed 3-cm abdominal aortic aneurysm was found to have expanded 2 cm in 3 weeks. Aortography documented some periaortic thickening and 2 mycotic aneurysms, one posterior at the level of the superior mesenteric artery and the second at the aortic bifurcation. After intensive antibiotic therapy, an endovascular approach to exclude the suprarenal mycotic aneurysm was undertaken in tandem with surgical excision of the infrarenal aneurysm. The harvested right common iliac artery was used to partially cover a Palmaz stent, which was deployed under direct vision just above the renal artery ostia so that the covered portion of the stent excluded the aneurysm. A right axillofemoral bypass with a femorofemoral bypass completed the revascularization. Postoperatively, the patient developed renal failure, ischemic colitis necessitating a left hemicolectomy, and paraplegia. Although the patient is paralyzed, the aneurysm remains excluded with patent visceral vessels at 12 months following surgery. No organisms were grown from excised aortic tissue, and no signs of recurrent infection have been seen.

CONCLUSIONS

Stent-graft repair may be able to lessen the invasiveness and reduce the morbidity associated with treatment of mycotic aortic aneurysms.

Endovascular repair of perisplanchnic abdominal aortic aneurysm with visceral vessel transposition

PURPOSE

To report a combined endoluminal and open surgical approach for a suprarenal abdominal aortic aneurysm (AAA) with coexistent splanchnic vessel stenoses.

METHODS AND RESULTS

A 64-year-old man presented with an aneurysm of the proximal abdominal aorta and severe stenoses of the celiac axis and superior mesenteric artery (SMA). An initial 2-stage plan to stent the visceral vessel stenoses and exclude the aneurysm with a fenestrated stent-graft failed when the celiac lesion could not be crossed. The approach was changed to restore visceral perfusion with a bifurcated left iliosplenic and ilio-SMA bypass graft. Exclusion of the aneurysm was achieved with a custom-made suprarenal aortic tube stent-graft (Ivancev-Malmö) system. The patient is free of symptoms at 22 months, and there was no aneurysm visible on the 14-month CT scan.

CONCLUSIONS

Hybrid techniques are an alternative treatment for complex perivisceral aortic aneurysms when total endovascular reconstruction is not possible.

Mortality rates following endovascular repair of abdominal aortic aneurysms

PURPOSE

To present the perioperative and late mortality following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs).

METHODS

Data were collected prospectively on 221 patients undergoing AAA EVR over a 4-year period (median 5-month follow-up). Patients were classified preoperatively as high risk with at least 1 of these features: serum creatinine > 150 micromol/L, ischemic heart disease or poor left ventricular function, respiratory function < 50% of predicted normal, ruptured or symptomatic AAA, contraindication to or failed open repair, and age > 80 years.

RESULTS

One hundred forty (63.3%) patients were classified as high risk, the most common criterion being cardiac disease (n = 96, 68.6%). There were 25 (11.3%) deaths in the 30-day perioperative period, 22 (15.7%) in the high-risk group compared to 3 (3.7%) in the acceptable-risk group (p = 0.02). The most common causes of perioperative death were multisystem organ failure and myocardial infarction. A further 21 (9.5%) late deaths occurred, 16 (11.4%) in the high-risk group and 5 (6.2%) in the acceptable-risk group (p > 0.1).

CONCLUSIONS

The mortality of patients at acceptable risk undergoing EVR compares with the best published series for conventional open AAA repair. The perioperative and late mortality in the high-risk patients are substantially higher.