Custom-made Stent Grafts Research Articles

Evaluating Branch Characteristics of off-the-shelf t-Branch and Custom-made Stent Grafts in Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Evaluating Branch Characteristics of off-the-shelf t-Branch and Custom-made Stent Grafts in Endovascular Repair of Thoracoabdominal Aortic Aneurysms

A 45-Year-Old Woman With Loeys-Dietz Syndrome and a 7-cm Intercostal Patch Aneurysm

We have provided a video and illustrations of a 45-year-old woman with Loeys-Dietz syndrome and a rapidly expanding 7-cm intercostal patch aneurysm. Her medical history was significant for prior aortic dissection and multiple open aortic repairs. She was treated with a custom-made stent graft using a total percutaneous transfemoral technique.

Iatrogenic aortocaval shunt treated by stent graft placement into the inferior vena cava

Fifty six year old male sustained an injury to the abdominal aorta during his 1992 lumbar disc surgery with subsequent aortocaval shunt formation. In order to close the shunt, his abdominal aorta and both common iliac arteries were ligated and bilateral aortoiliac bypass was implanted. Postoperatively the patient remained asymptomatic for several years. Subsequently he developed arterial hypertension, his exercise capacity diminished and he complained of exertional dyspnea. Intraarterial DSA demonstrated filling of the occluded aortic segment from intercostal and lumbar arteries as well and a shunt between this segment and the inferior vena cava. The hemodynamic significance of the shunt was confirmed using catheterization. Attempted reduction of the shunt flow by intercostal arteries embolization was not successful. We were successful in closing the fistula using a custom-made stent graft. CTA performed 18 years after the procedure confirmed absence of the shunt and patent inferior vena cava. The patient is now asymptomatic 23 years after the original surgery.

Acute Complex Endovascular Aortic Repair - Off-the-shelf vs. Surgeon-modified Stent Grafts

Treatment of complex abdominal and thoracoabdominal aortic aneurysms is challenging. Open surgical repair is a high-risk operation, especially in emergency cases. Endovascular aneurysm repair with a patient-specific custom-made stent graft in patients with symptomatic or ruptured complex aortic aneurysms is not possible, due to the manufacturing time required. In such cases, alternative endovascular techniques can be used. The "off-the-shelf" and "surgeon-modified" stent grafts are valid options for the endovascular treatment of complex aneurysms in urgent and emergent patients. The former are standardised commercially manufactured fenestrated or branched stent grafts, which are available off-the-shelf with an anatomical feasibility in 50 - 80% of the patients. The "surgeon-modified" stent grafts refer to a technique, in which a commercially available stent graft is modified by the surgeon under sterile conditions directly before the implantation, in order to add the required fenestrations, scallops and/or branches. The modification takes approximately 60 - 120 min and haemodynamic stability of the patient is mandatory. Because of the off-label use of the commercial stent graft, detailed patient consent about the modification complications and risks should be performed whenever possible. A comparison of results on mortality and morbidity between "off-the-shelf" and "surgeon-modified" stent grafts has been published, although a direct comparison would be unfair for several reasons (different design, lack of extensive outcomes reports, long learning curve and different modification techniques). The "surgeon-modified" and "off-the-shelf" fenestrated/branched stent grafts are used in the treatment of high-risk patients with symptomatic or contained ruptured complex aneurysms. The outcomes of the two techniques are good, although the long-term durability of the former should be further investigated.

Initial Results of Antegrade Laser Fenestrations Using Image Fusion Guidance and Company Manufactured Stent Grafts in Complex Aortic Aneurysm Repair

The aim was to describe initial outcomes of physician modified stent grafts using antegrade laser fenestrations and image fusion guidance (LEVAR) and company manufactured custom made (CM) stent grafts for the treatment of complex abdominal aortic aneurysms (CAAAs), thoraco-abdominal aortic aneurysms (TAAAs) and type I endoleaks (T1ELs). This was a retrospective single centre study. All LEVAR and Zenith (Cook) CM stent graft procedures between 1 January 2012 and 31 December 2018 were reviewed. Endpoints included intra-operative adverse events (IOAEs), in hospital mortality, re-interventions, target vessel patency, and 12 month outcomes (overall survival, freedom from re-intervention, target vessel patency). Outcomes at 12 months were estimated using the Kaplan-Meier method. A hundred patients were identified and included in the study. All patients were deemed unfit for open repair. The cohort included 22 LEVAR and 78 CM stent grafts. LEVAR cases included painful aneurysms (n= 5), > 65 mm aneurysms (n= 10), anatomical constrains and/or presence of previous renal stents (n= 7) or cases declined by the manufacturer planning centre (n= 2). IOAEs were recorded in 41% of cases (n= 9) in the LEVAR group vs. 10% (n= 8, p= .002) in the CM group. The in hospital mortality rate in the LEVAR group was 9% (n= 2) vs. 4% (n= 3, p= .30) in the CM group. The median follow up duration was 22 months (7 - 38) in the LEVAR group and 28 months (11 - 78) in the CM group. The estimate of overall survival at one year was 91% in both groups. The freedom from re-intervention rate at one year was 58% in the LEVAR group vs. 87% in the CM group. The target vessel patency rates at one year were 95% in both groups. In high risk patients deemed unfit for open repair, LEVAR may provide satisfactory 12 month overall survival and target vessel patency rates, though reported IOAE, mortality, and re-interventions rates were high thus requiring close and extensive follow up.

Stroke rate after thoracic endovascular aortic repair using de-airing of stentgrafts with high-volume of saline solution.

Background: Our aim was to determine the rate of ischemic stroke following thoracic endovascular aortic repair (TEVAR) after reducing gas volume released during stentgraft deployment by de-airing of thoracic stentgrafts with high-volume of 0.9% heparinized saline solution. Patients and methods: A single center retrospective analysis of all consecutive patients undergoing TEVAR from 2014 to 2019 was performed. All thoracic stentgrafts were flushed with 120ml 0.9% heparinized saline solution before implantation, according to our institutional protocol. Endpoints were in-hospital rates of ischemic stroke and spinal cord ischemia (SCI), and all-cause mortality. Results: One hundred and fifty-four patients (mean age: 66.8±13.6years, 64.9% males) were treated with TEVAR during the study period. Indications for treatment were thoracic aortic aneurysms (n=75, 48.7%), acute type B aortic dissections (n=46, 29.9%), aortic arch aneurysms and penetrating aortic ulcers (n=28, 18.2%), and blunt traumatic aortic injuries (n=5, 3.2%). Timing of procedure was urgent in 75 patients (48.7%). Proximal landing zone were zone 0-1-2 (n=75, 48.7%), zone 3 (n=66, 42.9%) and zone 4 (n=13, 8.4%). Supra-aortic vessels were revascularized with custom-made fenestrated stentgrafts in 9 patients (5.8%), using chimney technique in 4 patients (2.6%), and with debranching procedures in 19 patients (12.3%). Left subclavian artery was covered without revascularization in 46 patients (29.9%). In-hospital stroke occurred in two patients (1.3%) and SCI in another two patients (1.3%). In-hospital mortality rate was 0.6%. No further in-hospital events were noted. Conclusions: De-airing of stentgrafts with high-volume of 0.9% heparinized saline solution seems to be safe and can be used as an adjunct to keep occurrence of neurological events after TEVAR as low as possible.

Use of custom-made scalloped thoracic stent grafts in different hostile aortic anatomies

Use of custom-made scalloped thoracic stent grafts in different hostile aortic anatomies

Short-term outcomes of inner branches for endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms.

ObjectivesTo report our early experience using endografts with inner branches for the treatment of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs).MethodsA retrospective analysis of all patients treated in our institution for complex abdominal aortic aneurysms and TAAAs with custom-made stent grafts consisting of one or more inner branches. Data collected included patients demographics, aortic aneurysm morphology, stent grafts features, perioperative morbidity and mortality and short-term reintervention and mortality rates.ResultsTwenty-seven patients (18 males, mean age 70 ± 7.1) were included. Indications for surgery included TAAAs (12, 41%) juxtarenal abdominal aortic aneurysms (10, 37%), type 1A endoleaks (4, 15%) and paraanastamotic aneurysms (1, 4%). A total of 90 inner branches were used. Twenty-one (78%) of the stent grafts consisted only of inner branches and six (22%) had a combination of inner branches with either fenestrations or outer branches. Technical success was achieved in 26/27 (96%) of the patients. There was one perioperative mortality. Six patients suffered from major perioperative adverse events. Mean follow-up was seven months (range 1–23). During the follow-up period, four patients (15%) required reinterventions. Branch-related reinterventions were performed in two (7%) patients. No occlusions of inner branches occurred during the follow-up.ConclusionsInner branches in branched endovascular aneurysm repairs offer a feasible option for the treatment of complex abdominal aortic aneurysms and TAAAs. The procedures can be completed with high technical success and with acceptable short-term branch-related reintervention rates. Further follow-up is required to determine the long-term durability of this technology.

One-year results of the REP multicentric study of the proximal scalloped Relay thoracic stentgrafts for the treatment of the lesions of the aortic arch

This was a prospective and multicentric study evaluating the postoperative and one-year results of proximal scalloped custom-made stentgrafts for the endovascular treatment of the lesions of the aortic arch.

One-stage off pump combined transapical aortic valve replacement and ascending aorta endografting.

An 84-year-old patient was referred for severe symptomatic aortic valve stenosis and focal chronic dissection of the ascending aorta. After multidisciplinary discussion, the patient was scheduled for combined transapical transcatheter aortic valve replacement and ascending aorta stent-grafting. The procedure was performed with a balloon aortic valvuloplasty followed by a custom-made stent graft implantation into the ascending aorta and then by balloon-expandable transapical transcatheter aortic valve replacement. The patient had an uneventful hospital stay. In conclusion, in selected high-risk patients, transapical combined ascending aorta stent-grafting and transcatheter aortic valve replacement are feasible and safe.

Changes in Target Vessel Anatomy Following Fenestrated Endovascular Aneurysm Repair: Midterm Results

Purpose: To analyze the changes in target vessel (TV) anatomy after fenestrated endovascular aneurysm repair (fEVAR) during midterm follow-up. Materials and Methods: A retrospective single-center study analyzed 56 patients (mean age 71±7 years; 49 men) who underwent fEVAR using custom-made stent-grafts (22 Zenith and 34 Anaconda) between June 2010 and July 2016. Advanta V12 (V12; 74, 53%) and BeGraft (BeG; 66, 47%) stent-grafts were used to bridge to the 140 TVs. Measurements of the TV deviation at the aortic origin, the vessel shift distal to the bridging stent-graft (BSG), and the outer and inner BSG curve lengths were performed after 3-dimensional reconstruction of the serial computed tomography angiography scans. The results of the measurements for the main devices, the TVs, and the bridging stent-grafts were compared using univariable and multivariable analysis. Results: Of the 140 BSGs examined (74 V12s and 66 BeGs), 393 measurements (38 celiac trunks, 102 superior mesenteric arteries, 121 left renal arteries, and 132 right renal arteries) were analyzed. The outer/inner BSG curve length ratio was larger after implantation of Zenith devices compared with Anaconda (p<0.001). The vessel shift distal to the BSG was significantly associated with the interaction of the TV and type of BSG only in the univariable analysis (p=0.001). There were no significant changes of the TV deviation at the aortic origin. Only the outer BSG curve length was significantly associated with TV complications (p=0.033). Median follow-up was 24 months (range 2–61). The BSG curve length ratio showed a significant increase over time (p<0.001) but did not differ between the BeG and V12 (p=0.381). Conclusion: No difference was found between the V12 and the BeG stent-grafts regarding anatomical TV changes during midterm follow-up after fEVAR. Both stent-grafts adapt to the TV anatomy over time, and moderate anatomical changes seem to be tolerated without increasing the risk for TV complications. The type of main device also influences the TV anatomy.

Complex Endovascular Aortic Repair with a Branch for an Intercostal Artery in Marfan Patient

Introduction: Spinal cord ischemia (SCI) caused by intercostal artery occlusion in combination with procedural factors such as hypotension is the Achilles heel of open and endovascular TAAA-repair report a case of branched endovascular aortic repair including a branch for a large intercostal artery as a protective method in a patient at risk for spinal cord ischemia (SCI). We report a case of branched EVAR (bEVAR) in a Marfan patient with a 6cm Type IV TAAA including a branch for a large previously re-implanted intercostal artery. Methods: A 43-year-old patient with known Marfan syndrome presented with a type IV thoraco-abdominal aortic aneurysm (TAAA) and history of multiple previous cardiac and aortic operations over the past 28 years. The maximum diameter of the aneurysm was 60mm. The patient had two right renal arteries and two re-implanted segmental arteries. With the goal to preserve both right renal arteries and one large intercostal artery a 6-branched custom-made stent-graft was planned and manufactured. A custom-made stent-graft (Cook Medical, Bjaeverskov, Denmark) was planned. The branched component was planned to land in the mid/distal descending thoracic aorta with antegrade branches for the CA, SMA and renal arteries and a retrograde branch on the opposite left side for the intercostal artery. The retrograde branch for the intercostal artery was positioned at 5:00 o'clock in order to allow a spiral course of the bridging covered stent to the origin of the vessel at 9:30 o'clock with a lower risk of kinking. Bilateral femoral and right brachial artery access was used. The intercostal artery was catheterized and connected to the retrograde branch from femoral access successfully. Results: Selective angiography of the target vessels and final angiography demonstrated good sealing and unimpeded branch-perfusion, without endoleak. The patient was discharged from hospital to home on postoperative day 10 without complications. Six-month-follow up CTA demonstrated unchanged well-fitting endo-graft-position with good sealing and patency of all six branches including the two branches on the right renal artery and the branch to the intercostal artery (Figure. 5). The TAAA-diameter had significantly decreased from 60mm to 42mm and no signs of endoleak were present. Conclusion: Branched endovascular aortic repair with a branch to a large intercostal artery was technically feasible and clinically successful. Disclosure: Tilo Kölbel has intellectual property with Cook Medical, receives royalties, research, travel and educational grants, speaking fees and is consultant and proctor with Cook Medical. Nikolaos Tsilimparis receives travel and educational grants, speaking fees and is proctor with Cook Medical.

Abdominal Aortic Aneurysm Repair in Renal and Liver Transplant Recipients.

Abdominal aortic aneurysm (AAA) repair in patients with organ transplant remains a challenge. We looked at AAA repair in patients with organ transplants at our tertiary liver and kidney transplant unit. A retrospective analysis of a prospectively maintained database was undertaken from January 2008 to July 2018. We looked at patient demographics, type of repair, and technical success including reinterventions, perioperative transplant organ function, and 30-day and 1-year survival rate. Eight of 662 patients who underwent AAA repair had a solid organ transplant. Of these, 5 were kidney transplants, 2 liver transplants, and 1 had kidney and liver transplant; 75% were male; and average age was 63.4 (range: 49-83). All patients had asymptomatic AAAs, and 6 were treated with standard endovascular repair, 1 standard repair with iliac branch device, and 1 open repair. Adjunctive techniques such as CO2 angiograms, deployment of main body through contralateral iliac, low-profile sheaths, custom-made stent grafts, and temporary axillo-femoral shunting were used to protect transplant organs. Thirty-day survival was 100% with 1 death at 5 months from liver failure, and 1 patient has a persistent type-2 endoleak 3 years after the procedure. Abdominal aortic aneurysm repair in patients with organ transplants can be undertaken using adjunctive endovascular and open surgical techniques.

Single Centre Experience with Anaconda Custom-made Fenestrated Stent Graft in the Endovascular Repair of the Juxtarenal Aneurysms

Aim: The fenestrated Anaconda custom-made stent graft is one of the recently widely accepted fenestrated devices for managing complex juxta- and pararenal aortic pathology. This study showed its feasibility for treatment of challenging juxtarenal anatomy of the abdominal aorta. Methods: Over the period of 12 months, 9 patients with juxtarenal aortic aneurysm underwent fenestrated stent graft implantation in our institution. The graft fenestrations were customized on the basis of computerized tomography (CT-Angiography; CTA). Selected visceral ostia were protected with covered balloon-expandable stents after partial stent graft deployment. The perioperative and short term data were collected prospectively. Results: The mean aneurysm diameter was 58.4 mm (range 46-73 mm). The mean infrarenal neck length was 3.5 mm (range 0-7 mm), no patient had a severe (&gt;60°) angulation of proximal neck. 18 fenestration for renal arteries, 1 for SMA and 3 for coeliac´s were treated with Advanta V12 covered stent. All the target vessels were cannulated successfully through fenestrations and all the stent grafts were successfully deployed in patients with no technical issue in the release mechanism. All the patients have undergone 6 month follow-up, no aneurysm related or aneurysm-unrelated deaths were reported. On the CTA scan, 3 of the patients had a weak type IIb endoleak; no type I or Type III endoleak was demonstrated. All target vessels were open without an instance of branch-stent stenosis/occlusion. No reintervention was needed. Conclusion: The usage of custom-made Anaconda fenestrated stent graft for endovascular treatment of juxtarenal aortic aneurysms is feasible with acceptable intermediate-term results.

Computational simulation of TEVAR in the ascending aorta for optimal endograft selection: A patient-specific case study

Thoracic endovascular aortic repair of the ascending aorta is becoming an option for patients considered unfit for open surgery. Such an endovascular procedure requires careful pre-operative planning and the customization of prosthesis design. The patient-specific tailoring of the procedure may call for dedicated tools to investigate virtual treatment scenarios. Given such considerations, the present study shows a computational framework for choosing and deploying stent-grafts via Finite Element Analysis, by supporting the device sizing and selection in a real case dealing with the endovascular treatment of a pseudoaneurysm. In particular, three devices with various lengths and materials were examined. Two off-the-shelf devices were computationally tested: one composed of Stainless Steel rings with a nominal length of 60 mm and another one with Nitinol rings and a distal free flow extension, with a nominal length of 70 mm. In third place, a custom-made stent-graft, also with Nitinol rings and containing both proximal and distal bare extensions with a nominal length of 75 mm, was deployed. The latter solution based on patient morphology and virtually benchmarked in this simulation framework, enhanced the apposition to the wall by reducing the distance between the skirt and the vessel from more than 6 mm to less than 2 mm in the distal sealing zone. Our experience shows that in-silico simulations can help choosing the right endograft for the ascending aorta as well as the right deployment sequence. This process may also encourage vendors to develop new devices for cases where open repair is unfeasible.

Mid-term Results of Scalloped Thoracic Stentgrafts to Treat Aortic Lesions Involving the Arch

To evaluate the mid-term results of custom-made stentgrafts with a proximal scallop for the endovascular treatment of aortic lesions involving the arch.

Endovascular Treatment of Aortic Arch Lesions Using Scalloped Endografts.

To present our early and midterm results using thoracic endovascular aortic repair (TEVAR) with a custom-made proximal scalloped stent graft to accommodate left common carotid artery (LCCA) and innominate artery (IA) in treating aortic lesions involving the arch. Between February 2014 and April 2017, select patients presenting with aortic arch lesions and short proximal landing zone were treated by proximal scalloped Relay Plus stent grafts. Patient demographics, operative details, clinical outcomes, and complications were analyzed. Six patients (50% male) with a median age of 71 years (range, 60-82) underwent scalloped TEVAR using thoracic custom-made Relay Plus stent graft to preserve flow in the proximal supra-aortic trunks. Target vessels for the scallop were LCCA in 5 cases and IA in 1 case. The technical success rate was 100%, and proximal seal was achieved in all cases with no type I endoleaks on completion angiography. The median follow-up period was 20 (7-32) months. No conversion to open surgical repair and no aortic rupture occurred. One patient had a distal type I endoleak on the 6-month computed tomography (CT) scan, and 1 patient had a proximal type I endoleak on the 12-month CT scan. There was no stroke, paraplegia, retrograde type A dissection, or other aortic-related complication. We routinely used temporary rapid right ventricular pacing to obtain a near-zero blood pressure level during the graft deployment. No complications were observed related to the use of rapid pacing. When anatomy allows, proximal scalloped stent graft to accommodate LCCA and IA is a viable therapeutic option in treating aortic lesions involving the arch with short proximal landing zones. In addition, these findings represent a strong argument for the use of temporary rapid pacing during graft deployment.

Acute Type A Aortic Dissection Treated Using a Tubular Stent-Graft in the Ascending Aorta and a Multibranched Stent-Graft in the Aortic Arch

Purpose: To describe the combined use of a tubular stent-graft for the ascending aorta and an inner-branched arch stent-graft for patients with acute type A aortic dissection. Technique: The technique to deploy these modular, custom-made stent-grafts is demonstrated in 2 patients with acute DeBakey type I aortic dissections and significant comorbidities precluding open surgery. Both emergent procedures were made possible by the availability of suitable devices manufactured for elective repair in other patients. After preliminary carotid-subclavian bypass, a long Lunderquist guidewire was introduced from the right femoral artery to the left ventricle for delivery of the Zenith Ascend and Zenith Branched Arch Endovascular Grafts under inflow occlusion. Bridging stent-grafts were delivered to the innominate and left common carotid arteries to connect to the 2 inner branches; the left subclavian artery was occluded. Both cases were technically successful and resulted in exclusion of the false lumen in the ascending aorta. The operating and fluoroscopy times did not exceed those of comparable elective procedures. The patients were rapidly extubated shortly after the procedure and without serious immediate complications. One patient survived 11 months with a satisfactory repair; the other succumbed to complications of recurrent pneumonia after 23 days. Conclusion: Endovascular treatment of patients with acute type A aortic dissection using a combination of tubular and branched stent-grafts in the ascending aorta is feasible and offers an alternative strategy to open surgery.

Structural implications of fenestrated stent graft misalignment

BackgroundEndovascular aneurysm repair is a minimally-invasive method for the treatment of abdominal aortic aneurysms. For aneurysms that involve the visceral arteries, a custom-made stent graft with fenestrations for the branch arteries is required. The purpose of the current study is to evaluate the structural impact of misaligned fenestrations with respect to luminal patency and proximal aortic neck apposition in an in vitro model. MethodsA custom apparatus was used to evaluate seven Anaconda and three Zenith fenestrated stent grafts. All stent grafts were evaluated at 10° increments of stent/fenestration misalignment up to 80°. Images were captured at each interval and the luminal cross-sectional area and wall apposition were measured. ResultsThe Anaconda stent graft, which has an unsupported main body, demonstrated a linear reduction in luminal patency at increasing angles of misalignment (P < 0.0001). Stent/fenestration misalignments of 20° and 80° resulted in decreases in mean luminal patency of 14% and 54% respectively. The Zenith stent graft demonstrated a similar decrease in luminal patency, starting at misalignments of ≥40° (P < 0.0001). However, with stent/fenestration misalignments of ≥30°, apposition between the Zenith stent graft and the simulated aortic neck was compromised suggesting the creation of a type Ia endoleak. ConclusionsBoth the Anaconda and Zenith devices behave adversely at extreme angles of misalignment with luminal narrowing in the Anaconda device and loss of wall apposition in the Zenith device; however, both stent grafts appear to be equivalent at low angles of misalignment.

Clinical significance of type I endoleak on completion angiography.

PurposeType I endoleak is known to be associated with sac enlargement and occasional rupture, therefore, the treatment of type I endoleak is recommended at the time of diagnosis. The aim of this study was to identify the significance of early type I endoleak found on completion angiography.MethodsBetween January 2000 and December 2012, a total of 86 patients underwent endovascular abdominal aortic aneurysm repair (EVAR) and 10 patients (11.6%) were diagnosed with type Ia endoleak on completion angiography. Clinical and radiologic data were reviewed retrospectively.ResultsOf the 10 patients, two underwent EVAR with custom-made stent-grafts in the initial stage and both of them needed immediate treatment: one case involved open repair while the other involved insertion of an additional stent-graft. In 8 patients, the amount of leakage decreased after repeated balloon molding. They were managed conservatively and followed up with computed tomography angiography within 2 weeks after EVAR. In 7 of the 8 cases, type Ia endoleaks disappeared. In one patient with a persistent endoleak and a folded posterior wall of the stent-graft, coil embolization was performed 1 week after EVAR. With a median follow-up of 12 months (range, 1-61 months), no patients showed recurrence of type I endoleak or sac expansion.ConclusionType I endoleaks diagnosed on completion angiography sealed spontaneously in 7 of 10 patients (70.0%). In cases of decreased amounts of leakage after balloon molding, simple observation may be an alternative to repetitive procedures. The long-term follow-up of patients with self-sealed type I endoleaks is mandatory.