Physician-modified Stent Grafts Research Articles

The Utility of Three-Dimensional Printing in Physician-Modified Stent Grafts for Aortic Lesions Repair.

Background: Three-dimensional (3D) printing is becoming increasingly popular around the world not only in engineering but also in the medical industry. This trend is visible, especially in aortic modeling for both training and treatment purposes. As a result of advancements in 3D technology, patients can be offered personalized treatment of aortic lesions via physician-modified stent grafts (PMSG), which can be tailored to the specific vascular conditions of the patient. The objective of this systematic review was to investigate the utility of 3D printing in PMSG in aortic lesion repair by examining procedure time and complications. Methods: The systematic review has been performed using the PRISMA 2020 Checklist and PRISMA 2020 flow diagram and following the Cochrane Handbook. The systematic review has been registered in the International Prospective Register of Systematic Reviews: CRD42024526950. Results: Five studies with a total number of 172 patients were included in the final review. The mean operation time was 249.95± 70.03 min, and the mean modification time was 65.38 ± 10.59 min. The analysis of the results indicated I2 of 99% and 100% indicating high heterogeneity among studies. The bias assessment indicated the moderate quality of the included research. Conclusions: The noticeable variance in the reviewed studies' results marks the need for larger randomized trials as clinical results of 3D printing in PMSG have great potential for patients with aortic lesions in both elective and urgent procedures.

Six-vessel fenestrated physician-modified stent grafts for treating thoracic aortic dissecting aneurysm and giant abdominal aortic aneurysm.

Six-vessel fenestrated physician-modified stent grafts for treating thoracic aortic dissecting aneurysm and giant abdominal aortic aneurysm.

Mechanical Comparison between Fenestrated Endograft and Physician-Made Fenestrations.

A fenestrated endograft (FE) is the first-line endovascular option for juxta and pararenal abdominal aortic aneurysms. A physician-modified stent-graft (PMSG) and laser in situ fenestration (LISF) have emerged to circumvent manufacturing delays, anatomic standards, and the procedure's cost raised by FE. The objective was to compare different fenestrations from a mechanical point of view. In total, five Zenith Cook fenestrations (Cook Medical, Bloomington, IN, USA) and five Anaconda fenestrations (Terumo Company, Inchinnan, Scotland, UK) were included in this study. Laser ISF and PMSG were created on a Cook TX2 polyethylene terephthalate (PET) cover material (Cook Medical, Bloomington, IN, USA). In total, five LISFs and fifty-five PMSG were created. All fenestrations included reached an 8 mm diameter. Radial extension tests were then performed to identify differences in the mechanical behavior between the fenestration designs. The branch pull-out force was measured to test the stability of assembling with a calibrated 8 mm branch. Fatigue tests were performed on the devices to assess the long-term outcomes of the endograft with an oversized 9 mm branch. The results revealed that at over 2 mm of oversizing, the highest average radial strength was 33.4 ± 6.9 N for the Zenith Cook fenestration. The radial strength was higher with the custom-made fenestrations, including both Zenith Cook and Anaconda fenestrations (9.5 ± 4.7 N and 4.49 ± 0.28 N). The comparison between LISF and double loop PMSG highlighted a higher strength value compared with LISF (3.96 N ± 1.86 vs. 2.7 N ± 0.82; p= 0.018). The diameter of the fenestrations varied between 8 and 9 mm. As the pin caliber inserted in the fenestration was 9 mm, one could consider that all fenestrations underwent an "elastic recoil" after cycling. The largest elastic recoil was observed in the non-reinforced/OC fenestrations (40%). A 10% elastic recoil was observed with LISF. In terms of mechanical behavior, the custom-made fenestration produced the highest results in terms of radial and branch pull-out strength. Both PMSG and LISF could be improved with the standardization of the fenestration creation protocol.

Early Results and Feasibility of Total Endovascular Aortic Arch Repair Using 3-Vessel Company-Manufactured and Physician-Modified Stent-Grafts.

Total endovascular repair of aortic arch aneurysms is feasible in select patients. This study aims to evaluate the feasibility and early outcomes of total endovascular arch repair using 3-vessel company-manufactured devices (CMDs) and physician-modified endo grafts (PMEGs). Patients unfit for open repair who underwent 3-vessel total arch repair at a single institution from 2018 to 2021 were reviewed. Patients received either 3-vessel inner-branch CMDs or PMEGs. Three-vessel designs were used to incorporate the innominate, left common carotid, and left subclavian arteries. The antegrade inner branches in both devices were accessed via right brachial or carotid approach. The left carotid was accessed via carotid cutdown or femoral approach. The left subclavian artery was accessed via transfemoral approach. The study endpoints included procedural technical success, patient survival, neurologic events, cardiac complications, reinterventions, and target artery patency. Nine patients underwent treatment. Four patients were treated with PMEGs, and 5 with CMDs. Procedural technical success was 100%. There were no in-hospital deaths. There were no strokes, transient ischemic attacks, myocardial infarction, or spinal ischemia in the perioperative period. Major adverse events occurred in 3 patients (33%). Two (22%) vascular access complications and one (11%) acute kidney injury occurred. One (11%) patient required early reintervention for an access complication. The median follow-up period was 358 days (CMD, 392 days; PMEG, 198 days). There was a late reintervention and conversion to open repair at 142 days of follow-up in a patient with a PMEG that developed an aortic infection, leading to death on postoperative day 239. The mean length of stay was 7±4 days. Computed tomography imaging obtained during the immediate postoperative period revealed endoleak in 6 (66%) patients, out of which 5 resolved spontaneously and 1 required reintervention via left subclavian artery stenting. Target artery patency was 100% at the end of the follow-up period. Three-vessel total endovascular aortic arch repair using a CMD or PMEG is feasible with optimal early outcomes. Physician-modified stent-grafts are a feasible option for patients who do not meet anatomic criteria for CMDs. Management of aortic arch disease remains a significant challenge in vascular surgery. This study showcases the feasibility and safety of using a total endovascular approach to repair the aortic arch, which could potentially reduce morbidity and mortality associated with traditional surgical approaches. The results suggest that this minimally invasive technique could be an alternative treatment option for high-risk patients and could significantly improve outcomes for those requiring aortic arch repair. Overall, this study represents a promising development in the field of endovascular surgery and highlights the potential to improve patient outcomes.

Three-Dimensional Printing to Guide Fenestrated/Branched TEVAR in Triple Aortic Arch Branch Reconstruction With a Curative Effect Analysis.

To summarize experience with and the efficacy of fenestrated/branched thoracic endovascular repair (F/B-TEVAR) using physician-modified stent-grafts (PMSGs) under 3D printing guidance in triple aortic arch branch reconstruction. From February 2018 to April 2022, 14 cases of aortic arch aneurysms and 30 cases of aortic arch dissection (22 acute aortic arch dissection and 8 long-term aortic arch dissection)were treated by F/B-TEVAR in our department, including 34 males and 10 females, with an average age of 59.84 ± 11.72 years. Three aortic arch branches were affected in all patients. A 3D-printed model was made according to computed tomography angiography images and used to guide the fabrication of PMSGs. All patients were followed up. A total of 132 branches were successfully reconstructed with no case of conversion to open surgery. The average operation time was 4.97 ± 1.40 hours, including a mean 44.05 ± 7.72 minutes for stent-graft customization, the mean postoperative hospitalization duration was 9.91 ± 4.47 days, the average intraoperative blood loss was 480.91 mL (100-2810 mL), and the mean postoperative intensive care unit monitoring duration was 1.02 days (0-5 days). No deaths occurred within 30 days of surgery. Postoperative neurological complications occurred in 1 case (2.3%), and retrograde type A dissection occurred in 1 case (2.3%). Compared with conventional surgery, triple aortic arch branch reconstruction under the guidance of 3D printing is a minimally invasive treatment method with the advantages of accurate positioning, rapid postoperative recovery, few complications, and reliable short- to mid-term effects. At present the PMSG usually depend on imaging data and software calculation. With the guidance of 3D printing technology, image data could be transformed into 3D model, which has improved the accuracy of the positioning of the fenestrations. The diameter reduction technique and the internal mini cuff technique have made a complement to the slimed-down fenestration selection process and the low rate of endoleak. As reproducible study, our results may provide reference for TEVAR in different cases.

Midterm Results of Physician-Modified Stent Grafts for Thoracoabdominal and Complex Abdominal Aortic Aneurysms Repair

To assess midterm results of physician-modified stent grafts (PMSG) for the treatment of emergent complex abdominal and thoracoabdominal aortic aneurysms (TAAA) in high-risk patients. All consecutive patients with emergent complex abdominal or TAAA undergoing PMSG technique between January 2012 and July 2019 were retrospectively included. Indications for PMSG were symptomatic aneurysms and rapidly growing aneurysms >70mm. Ruptured aneurysms were excluded. Thirty-three patients (mean age: 74 +/- 11years) were included. The mean aneurysm diameter was 76 +- 20mm. Patients presented with TAAA (n=20, 61%), complex abdominal aortic aneurysms (CAAA, n=9, 27%), type I endoleak after previous endovascular aneurysm repair (n=3, 9%) and intramural aortic hematoma (n=1, 3%). Chimney technique was performed in addition to PMSG in seven cases (21%). Intraoperative adverse events were recorded in seven cases (35%) in the TAAA group and one case (11%) in the CAAA group. In-hospital mortality rate was 15% (n=3) in the TAAA group and 11% (n=1) in the CAAA group. Moderate to severe complications were recorded in 45% of cases (n=15). Spinal cord ischemia occurred in two cases (6%, one case without residual deficit and one with minor motor deficit). One (3%) patient required transient hemodialysis. One patient presented with early aortic rupture and required an open conversion. The mean follow-up duration was 31months (1-79). Overall survival estimates were 81.4% (95% confidence interval [CI]: 63.1.-91.2) at 1year and 71.6% (95% CI: 52.6-84.1) at 2years. Freedom from reintervention rates at 1 and 2years were 61.2% (95% CI: 41.7-75.9) and 57.4% (95% CI: 37.9-72.8). Target vessel primary patency rates at 1 and 2years were 99.2% (95% CI: 94.2-99.9) and 97.7% (95% CI: 90.7-99.4). PMSG for high-risk patients with complex aneurysms provided acceptable technical success and excellent target vessel patency rates but were associated with a 12% in-hospital mortality rate. Reinterventions were frequent. This technique should be limited to selected high-risk patients for whom the risk of rupture in the short-term is deemed too high to wait for graft manufacturing of custom-made device.

Homemade fenestrated physician-modified stent grafts for arch aortic degenerative aneurysms.

We evaluated the early- and medium-term outcomes of single- and double-fenestrated physician-modified endovascular grafts (PMEGs) for total endovascular degenerative aortic arch aneurysm repair. We performed a single-center, retrospective analysis of prospectively collected data from 52 patients from August 2013 through January 2021 who had undergone homemade fenestrated thoracic endovascular aortic repair for degenerative aortic aneurysms. In all cases, a distal smaller fenestration for the left subclavian artery (LSA) was fashioned and was the only one stented. For a double-fenestrated endograft, a proximal larger fenestration that incorporated both the brachiocephalic trunk and the left common carotid artery was added. A total of 52 patients with degenerative aortic arch aneurysms were treated. Of the 52 patients, 36 were men, the mean age was 75± 8years, 31% had received a single LSA fenestration, and 69% had undergone double-fenestrated thoracic endovascular aortic repair. Of the 52 procedures, 5 (10%) were emergent procedures. The technical success was 100%. The median time required for stent graft modification was 22± 6minutes. The 30-day mortality was 2% (n= 1). Five patients (10%) had experienced a cerebrovascular event, including two transient ischemic attacks, one minor stroke with full neurologic recovery, and two with sequelae. Two patients (4%) had experienced perioperative retrograde dissection during follow-up. No patient had developed a type I, II, or III endoleak from the LSA. No patient had required reintervention. All supra-aortic trunks were patent. During a mean follow-up of 18± 11months, no patient had required conversion to open surgical repair, aortic rupture, or paraplegia. Single or double PMEG is a safe and suitable tool for the treatment of high morbidity pathology such as aortic arch degenerative aneurysm repair. In addition, this device can be used in patients requiring elective or emergency repair.

Physician-Modified Stent Graft for Blunt Thoracic Aortic Injuries: Do the Benefits Worth the Trouble?

Obtaining a suitable proximal landing zone in blunt thoracic aortic injuries (BTAI) often necessitates coverage of the left subclavian artery (LSA). This study aimed to evaluate the outcomes of physician-modified endovascular grafts (PMEGs) in this indication. We performed a retrospective analysis of a prospective registry including all patients who had undergone a thoracic endovascular aortic repair (TEVAR) for BTAI from October 2008 to October 2020. Starting in 2015, patients requiring coverage of the LSA were either treated using a physician-modified proximal scalloped or single-fenestrated stent graft. After an early postoperative computed tomography scan, follow-up was performed at 3 months, 6-months, and yearly. Among 58 patients treated with TEVAR for BTAI, 23 (39.6%) patients required a zone 2 landing zone of which 10 (17.2%) patients were treated with PMEGs. The median age was 48 [31-64.5] years, and 78.2% (n=18) patients were male. The median Injury Severity Score was 38 [27-55.5]. Coverage of the LSA was performed in 25.8% (n=15) of the total population in which 5 patients had an LSA transposition. The median modification time was 18 [14-27] minutes. Technical success of PMEGs was 90.0% overall and 100% for fenestrated stent grafts. No stroke, paraplegia, or retrograde dissection was observed. The primary patency of the LSA in the PMEGs group was 90 % at 1year and 28.8 % in the LSA coverage group (P<0.01). The use of PMEGs is feasible and effective in the management of BTAI with a short proximal landing zone. Further evaluation of long-term outcomes and durability are awaited.

Pararenal aortic aneurysm repair using a physician-modified stent-graft with inner branches.

A 90-year-old man had presented with a 55-mm pararenal aortic aneurysm (expansion rate, 6 mm/mo). Gutter endoleaks have limited the use of parallel grafts. Physician-modified fenestration is one of the effective techniques in emergency cases.1 However, its use has posed concerns regarding the development of endoleaks from fenestration sites.2 In addition, company manufactured devices have a time delay. Hence, we assembled inner branched stent grafts to reduce the possibility of a type IIIc endoleak.

Physician-Modified Stent-Grafts Created in the Three-Dimensionally Aortic Template Have Better Reliability and Greater Alignment With the Target Vessels Than Stent-Grafts Modified Based on Measurements From Computed Tomography.

Physician-modified stent-grafts (PMSG) are widely used, especially when a patient's condition precludes waiting for a custom-made device. In recent years, the modification process has been upgraded using 3-dimensional (3D) aortic templates. Nonetheless, the reliability of PMSG and accuracy of fenestration alignment with the target vessel are not known. Thus, the study is aimed to fulfill the gap in current knowledge. Ten computed tomographic (CT) scans of aortic aneurysm previously treated with the fenestrated endovascular repair were selected to 3D-print aortic templates and elastic vessel phantoms. Two vascular surgeons performed fenestrations using the 3D template and modification plan based on CT measurements. Two operators each performed 10 fenestrated stent-grafts in the aortic template and 10 using CT measurements, for a total of 40 fenestrated stent-grafts. Then, stent-grafts were implanted in elastic vessel phantoms, which served to evaluate fenestration alignment with the target vessel. The alignment was judged in a 5-point scale: 0%, 1% to 25%, 26% to 50%, 51% to 75%, and 76% to 100%. The distances between fenestrations served to calculate interobserver variability for both methods. The measurements were processed as interclass correlation coefficient (ICC), Pearson and Spearman correlation, and Bland-Altman plots. PMSG created with a 3D template had higher interclass correlation coefficient values and Pearson/Spearman correlation than fenestrations created from CT measurements. The rate of fenestration alignment with the target vessel was higher for PMSG created with a 3D template (p=0.007). PMSGs created with a 3D template are more reliable and have better fenestration alignment with the target vessel than PMSGs created based on CT measurements.

Initial Experience with Fenestrated Physician-Modified Stent Grafts Using 3D Aortic Templates.

The goal of this study was to describe the surgical results of physician-modified endografts (PMEG) utilizing a 3D aortic template in a center with no prior experience in complex endovascular aortic repairs. Forty-three patients underwent physician-modified graft stent implantation using a 3D aortic model. The inclusion criteria were juxtarenal and suprarenal aortic aneurysms, type IV thoracoabdominal aneurysms, and type IA endoleak after endovascular aortic repair. In asymptomatic patients, the diameter threshold for aneurysm repair was 5.5 cm in males and 5.0 cm in females. 3D aortic templates were prepared from the patient’s computed tomography angiography scans and sterilized before use in the operating suite. Forty-three stent grafts were modified with the use of a 3D printing template. A total of 162 reinforced fenestrations (37 celiac, 43 right renal, 39 left renal, 43 superior mesenteric) with a mean of 3.8 per patient were performed. All PMEGs had a posterior reducing-diameter tie and a preloaded guidewire. The mean modification time was 86 ± 12 min. The mean follow-up was 14 ± 12 months. The 30-day mortality was 12%. During the follow-up period, the patency rate was 95% per the superior mesenteric artery, 93% per right renal artery, 95% per left renal artery, and 89% per celiac trunk. Twelve (28%) patients had endoleak, of which type I or III was present in 5 (12%) patients, and type II in 7 (16%). 3D printing can be successfully integrated into the physician’s everyday practice of stent graft modification. However, the use of this approach in centers without experience performing complex aortic procedures results in worse surgical metrics than those previously reported.

Early experience with the Bolton Relay Pro/Plus for physician-modified fenestrated TEVAR.

Thoracic endovascular aortic repair (TEVAR) can be challenging in cases involving the aortic arch and the visceral segment. We report our initial experience with fenestrated TEVAR (f-TEVAR) for thoracic aortic disease involving aortic branches using physician-modified stent grafts (PMSGs). Between February 2019 and November 2020 nine patients were treated with a PMSG. Indication to treatment were a symptomatic acute type B aortic dissection (TBAD) in three cases, a penetrating aortic ulcer in three cases (two in zone 3 and one in zone 6), one case of an endoleak type IA after TEVAR, a chronic TBAD after TEVAR in one case and one case of a contained rupture of a thoracoabdominal aneurysm in zone 3. Pre-, intra- and postoperative clinical data were recorded. The median patient age was 65 (IQR 60.5-71) years, and eight (89%) patients were men. Nine stent grafts (six Bolton Relay Plus and three Bolton Relay Pro, Terumo Aortic, Vascutek Ltd., Inchinnan, UK) were deployed. Small fenestrations (8 mm) were created on table, median duration for on table stent graft modifications was 20 minutes (range 13-22). The technical success rate was 100%. Median operative time was 188 (range 116-252) minutes. No major adverse events of any sort occurred during the first 30-day postoperatively. There were no type I or type III endoleaks at the end of the procedure, and no cases of spinal cord ischemia. Two access related complications occurred (22%). After a median of 12 (range 5-12) months all patients survived and all target vessels remained patent with one case of fenestration-related type I endoleak, which required open conversion. The results of our initial experience with f-TEVAR using PMSGs with the Bolton Relay stentgraft for the treatment of aortic diseases are acceptable. These results should be confirmed on larger patient cohorts.

Early Results and Feasibility of Total Endovascular Aortic Arch Repair Using Three-Vessel Company-manufactured and Physician-modified Stent Grafts

Total endovascular repair of aortic arch aneurysms is feasible in select patients. Unfortunately, and because of anatomic constraints, some patients are ineligible for company-manufactured devices. This study aims to evaluate the feasibility and early outcomes of total endovascular arch repair using three-vessel company-manufactured and physician-modified stent grafts.

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).

Medium-term Outcomes of Double Fenestrated Physician-modified Stent Grafts for Total Aortic Arch Repair

Medium-term Outcomes of Double Fenestrated Physician-modified Stent Grafts for Total Aortic Arch Repair

Use of Inner Branches During Physician-Modified Endografting for Complex Abdominal and Thoracoabdominal Aortic Aneurysms

Endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms have been performed widely in an increasing number of centers, utilizing custom-manufactured or physician-modified stent grafts containing fenestrations and side-arm branches for visceral and renal artery incorporation. Alternatively, inner branch configurations may be useful in complex anatomy, where application of fenestrations or side-arm branches can be challenging. Our study aims to evaluate the incidence of target vessel instability when incorporated with inner branch configurations, and report clinical outcomes of patients who underwent fenestrated/branched endovascular aortic repairs (F-BEVAR) containing one or more inner branches. We reviewed patients who underwent F-BEVAR with at least one inner branch configuration for complex abdominal or thoracoabdominal aortic aneurysms at Keck Hospital of University of Southern California from 2014 to 2020. Endpoints were mortality, major adverse events (MAE), technical success, and target vessel instability. Target vessel instability was assessed using follow-up computed tomography (CT) and duplex imaging. Out of the 175 patients who underwent F-BEVAR for complex abdominal and TAAA during the study period, 17 patients had at least one inner branch configuration. All were deemed high-risk for open repair with multiple cardiovascular and/or pulmonary comorbidities. Eight (47%) patients had extent I, II, III thoracoabdominal aortic aneurysms, and 10 (59%) had prior aortic repairs. A total of 68 target vessels were incorporated (mean=4 vessels/patient, range=1~6), of which 40% were inner branch configurations, most commonly for renal arteries. Technical success was 94.1%. There was one perioperative mortality due to massive myocardial infarction, as well as one patient who needed temporary hemodialysis. No device-related mortalities were observed. At 30 days, primary inner branch patency was 100% with no target vessel instability or reintervention. At mean follow-up of 5.8 months, the overall survival was 94% with one patient who expired from unknown cause. Overall primary inner branch patency was 96.3%, due to occlusion of a long lumbar artery branch with no clinical sequelae. Inner branch configurations can provide a safe alternative technique of branch incorporation during complex endovascular aortic repair.

Conceptual, cost, regulatory, material properties, and sterilization considerations in three-dimensional printed template-assisted physician modified stent grafts for fenestrated endovascular aneurysm repair

Conceptual, cost, regulatory, material properties, and sterilization considerations in three-dimensional printed template-assisted physician modified stent grafts for fenestrated endovascular aneurysm repair

Endovascular aortic arch repair with a pre-cannulated double-fenestrated physician-modified stent graft: a benchtop experiment.

The critical step in total endovascular aortic arch repair is to ensure alignment of fenestrations with, and thus maintenance of flow to, supra-aortic trunks. This experimental study evaluates the feasibility and accuracy of a double-fenestrated physician-modified endovascular graft [single common large fenestration for the brachiocephalic trunk and left common carotid artery and a distal small fenestration for left subclavian artery (LSA) with a preloaded guidewire for the LSA] for total endovascular aortic arch repair. Eight fresh human cadaveric thoracic aortas were harvested. Thoracic endografts with a physician-modified double fenestration were deployed for total endovascular aortic arch repair in a bench test model. A guidewire was preloaded through the distal fenestration for the LSA. All experiments were undertaken in a hybrid room under fluoroscopic guidance with subsequent angioscopy and open evaluation for assessment. Mean aortic diameter in zone 0 was 31.3 ± 3.33 mm. Mean duration for stent graft modification was 20.1 ± 5.8 min. Mean duration of the procedure was 24 ± 8.6 min. The Medtronic Valiant Captivia stent graft was used in 6 and the Cook Alpha Zenith thoracic stent graft in 2 cases. LSA catheterization was technically successful with supra-aortic trunk patency in 100% of cases. The use of a double-fenestrated stent graft with a preloaded guidewire appears to be a useful technical addition to facilitate easy and correct alignment of stent graft fenestrations with supra-aortic trunk origins.

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.

A Flexible 3D Printed Template to Assist with Physician Modified Endografts for FEVAR

Fenestrated endovascular aneurysm repair (FEVAR) for juxtarenal AAAs is limited by cost and the availability of custom made endografts, in addition to technical complexity. Rigid 3D printed anatomical models of the visceral aorta have been used to supplement fenestration placement and as an alternative to conventional centreline based planning; however, these do not simulate the geometric interaction between wires, delivery system, endograft, and aortic tissue. We present a novel translucent, flexible 3D printed template which simulates aortic conformation. Flexible templates better approximate the straightening of native aorta when endografts are deployed and may assist fenestration planning to reduce the risk of splanchnic vessel misalignment. The visceral segment of a juxtarenal AAA was modelled from a computed tomography aortogram, with the splanchnic vessels cropped at their origin to allow fenestrations to be marked (Fig. 1). A Projet 3500 3D printer (3D Systems Corporation, Rock Hill, USA; cost €70 000) was used to print the flexible template. The 3D printed templates are sterilised using ethylene oxide or autoclave techniques. Lunderquist wire cannulation was performed with deployment of an off the shelf Endurant endograft (Medtronic Inc., Minnesota, USA). Splanchnic branch ostia were marked with a sterile pen (Fig. 2). The material was translucent to avoid positioning the fenestrations over struts.Figure 2Fenestrations are planned by marking through the template with a sterile marking pen.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The template was 3D printed in flexible resin (Visijet CE-NT, 3D Systems) on its first attempt over 24 h, costing €95 in materials. This presents a significant time advantage over commercial fenestrated endografts, which require a minimum of one month lead time. In addition, 3D printed template assisted physician modified stent grafts result in substantial cost savings when compared with commercial alternatives. Flexible models may also assist with validation of commercial FEVAR graft construction. 3D printed templates to assist with the back table fenestration of standard commercial endografts are a promising frontier for FEVAR. We report the first instance of a flexible template which mitigates some limitations surrounding templates 3D printed with rigid materials. None.