Comprehensive Review of Physician Modified Aortic Stent Grafts: Technical and Clinical Outcomes

Standardized approach for four-fenestrated physician-modified endograft to treat complex abdominal aortic aneurysms using Valiant Captivia

We describe the feasibility and safety of a standardized approach for four-fenestrated physician-modified endograft (PMEG) placement to treat complex abdominal aortic aneurysms using the Valiant Captivia platform (Medtronic). The standardization is based on specific selection criteria for anatomical feasibility, measurement method, and modification technique of a single endograft type. Six cases (two juxtarenal, two pararenal, and two type IV thoracoabdominal aneurysms) were treated, with 24 target vessels incorporated with fenestrations. Four cases were treated in an urgent setting and two were elective. The time modification required was 121 ± 18 minutes. Technical success was 100%, with no mortality or complications at 30 days. Postoperative computed tomography at 3 months demonstrated complete aneurysm exclusion, without a type I or III endoleak, no main graft- or fenestration-related loss of integrity, and no target vessel misalignment or stent fracture. The present standardized approach seems safe and feasible and might represent an initial benchmark for comparison with future studies.

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.

Physician-modified versus chimney endografting for pararenal aortic aneurysms: a systematic review and meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis to assess the existing published evidence regarding the safety and efficacy of the endovascular aortic repair with chimney technique (ch-EVAR) and physician-modified stent-grafts (PMSGs) for the treatment of pararenal aortic aneurysm repair.

EVIDENCE ACQUISITION

A systematic search of all relevant studies reported until October 2023 according to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines was performed. The pooled 30-day mortality, peri- and postoperative complication rates were estimated using fixed or random effect methods.

EVIDENCE SYNTHESIS

A total of 679 study titles were identified by the initial search strategy, of which 16 were considered eligible for inclusion in the meta-analysis. A total of 1094 patients (ch-EVAR N.=861 and PMSG N.=233) (90% male) were identified. The pooled 30-day mortality rate was 3.4% for ch-EVAR and 2.6% for PMSG. The major adverse events (MAE) in the early period was 14.7% for ch-EVAR and 18.5% PMSG, respectively. Higher occlusion rate was observed of the chimney stents grafts (8.2%) than the bridging stents (1.4%) during the follow-up period.

CONCLUSIONS

Ch-EVAR and physician-modified technology are safe with low 30-day mortality in elective settings for pararenal aortic aneurysms repair. No significant differences were seen between the two surgical methods regarding the early major adverse events rate. However, higher occlusion rate for the chimneys can be expected over time.

Midterm outcomes of physician-modified endovascular stent grafts for the treatment of complex abdominal aortic aneurysms in Korea: a retrospective study

Purpose

Physician-modified endovascular stent grafts (PMEG) are a good treatment option for complex abdominal aortic aneurysms (AAAs), especially in high-risk patients not amenable to open repair, and when commercial fenestrated devices are not available. We report our single-center experience with PMEG for the treatment of complex AAAs.

Methods

We retrospectively reviewed patients who underwent PMEG repair for AAA from November 2016 to September 2020 at our institution. Demographic data, anatomic characteristics, perioperative and postoperative outcomes, major adverse events, and 30-day mortality were analyzed.

Results

We identified 12 patients who underwent PMEG for complex AAA. The mean age was 74 years and the mean maximal AAA diameter was 58.1 mm. Indications for treatment included 4 impending or contained ruptures, 2 mycotic aneurysms, and 6 symptomatic cases. The technical success rate was 91.7%. Aneurysm sac regression was observed in 7 patients (58.3%), including 2 cases of complete regression. There was 1 aneurysm-related mortality at 3 months due to mycotic aneurysm. Also, there was 1 postoperative complication case of transient renal failure requiring temporary dialysis. At 1 year, there was 1 branch occlusion from the initial failed cannulation case and 2 type 1A endoleaks, and there was 1 case of open explantation.

Conclusion

PMEG showed a low technical failure rate and acceptable midterm stent durability and sac stability, comparable to conventional endovascular aneurysm repair. Despite the small number of cases, there was a tendency for a high sac regression rate, although longer follow-up is needed.

Anatomic Feasibility of In-Situ Fenestration for Isolate Left Subclavian Artery Preservation during Thoracic Endovascular Aortic Repair Using an Adjustable Needle Puncturing System

OBJECTIVES

To evaluate the feasibility of thoracic endovascular aortic repair (TEVAR) using the Ankura™ device (Lifetech Scientific, Shenzhen, China) with left subclavian artery (LSA) in-situ fenestration (ISF) using an adjustable puncture device system.

METHODS

It is a single center, retrospective, financially unsupported cohort study of TEVAR performed from 16 February 2007 to 10 January 2023. Inclusion criteria were isolate LSA revascularization for elective or urgent/emergent "zone 2" TEVAR, and the availability of the preoperative computed tomography angiography.

RESULTS

Post-hoc analysis identified 52 TEVARs. There were 39 (75.0%) males, and 13 (25.0%) females: median age was 74.5 years (IQR, 65.5-78). Index TEVAR was performed for atherosclerotic aneurysm in 27 (51.9%) cases, dissection-related diseases in 18 (34.6%), penetrating aortic ulcer in 5 (9.6%), and blunt traumatic aortic injury in 2 (3.8%). Access-vessel feasibility rate of TEVAR using the Ankura™ device would have been 98.1% (51/52). Considering the morphology of the aortic arch, ISF TEVAR feasibility would have been 61.5% (32/52). Binary logistic regression analysis identified LSA angulation (OR: 1.1, 95%CI: 1.03-1.14, p = 0.003) to be associated with ISF feasibility using this endograft and a self-centering adjustable needle-based puncture device.

CONCLUSIONS

Potential feasibility of TEVAR using the Ankura™ endograft with ISF using a self-centering adjustable needle system was 61.5%. Left subclavian artery angulation seems to be the most important and limiting anatomical constraint.

Assessment of Thoracic Endovascular Aortic Repair Using Relay Proximal Scallop: Results of a French Prospective Multicentre Study

OBJECTIVE

A proximal scallop design allows aortic arch repair without complex endovascular manipulation in the aortic arch. The aim was to assess the safety and efficacy at one year of the Relay proximal scallop stent graft.

METHODS

A prospective multicentre study evaluated consecutive patients treated with the Relay proximal scallop stent graft in 10 French aortic centres. All consecutive patients eligible for elective thoracic endovascular repair with proximal scallop in the 10 participating centres between January 2015 and July 2018 were included. Primary endpoints were 30 day mortality, stroke, and spinal cord ischaemia (SCI) rates. Outcomes including safety and efficacy, technical and clinical success, all cause death, neurological events, vessel patency, and device specific complications were analysed. Survival and survival without severe complications were estimated using Kaplan-Meier estimates.

RESULTS

Ten aortic centres treated 40 patients for thoracic aortic aneurysm (45%), penetrating atherosclerotic aneurysm (30%), and dissection (25%). Half of the procedures (50%) targeted zone 0 of the aortic arch (zone 0 in 17.5% and zones 0/1 in 32.5%), 37.5% targeted zone 2 (35% zone 2 alone; 2.5% zones 1/2), and 15% targeted zone 1 (12.5% zone 1 alone). Median follow up was one year. Thirty day mortality, stroke, and SCI rates were 10%, 5%, and 0% respectively. Primary technical success was 95%. Type Ia, Ib, and III endoleaks rates were 5.4%, 0%, and 0% respectively at one month. The overall mortality rate at one year was 17.5%. Aneurysm expansion was > 5 mm in one case at one year associated with type Ia endoleak (3%). There was no supra-aortic trunk thrombosis, one (2%) graft kink, and no migration.

CONCLUSION

One year outcomes showed that the Relay proximal scallop stent graft is an acceptable answer to thoracic aortic disease to deal with short proximal landing zones.

Physician-Modified Endografts for the Treatment of Thoracic Aortic Pathologies Involving the Aortic Arch

OBJECTIVE

This study aimed to evaluate the outcomes of physician-modified endografts (PMEGs) for the treatment of thoracic aortic pathologies involving the aortic arch.

METHODS

A retrospective single-center study was performed on consecutive patients with thoracic aortic pathologies treated by PMEGs between February 2018 and May 2022. Data on baseline characteristics, operative procedure, and follow-up information were collected. The endpoints included technical success, complications, mortality, overall survival, re-intervention, and target vessel instability.

RESULTS

This study comprised 173 patients (mean age=58±13, range=28-83, 148 men) with thoracic aortic pathologies, including 44 thoracic aortic aneurysms, 113 aortic dissections (9 type A, 4 residual type A, 75 type B, 32 non-A non-B), 3 aortic intramural hematomas, and 13 penetrating aortic ulcers. Thirty-five of the patients had PMEGs with 3 fenestrations, 32 had 2 fenestrations, and 106 had 1 single fenestration. Technical success was 98% (170/173), and the 30-day mortality was 2% (3/173). Perioperative complications included stroke (n=3, 2%), retrograde type A dissection (RTAD; n=3, 2%) and renal injury (n=3, 2%). Seven deaths (4%) were noted during a median follow-up of 11 (range=1-52) months. Eleven cases of re-intervention were stent-related. There were 5 type Ia endoleaks (3%), 2 type III endoleaks (1%) from the innominate artery (IA), and 3 type Ic endoleaks (2%) from the left subclavian arteries. One case of IA stent-graft (SG) stenosis was noted because of mural thrombus. Estimate rates of overall survival, freedom from secondary intervention, and freedom from target vessel instability at 2 years were 93.4% (95% confidence interval [CI]=88.7%-98.1%), 80.7% (95% CI=73.3%-88.1%), and 89.0% (95% CI=80.4%-97.6%), respectively.

CONCLUSIONS

Physician-modified endografts showed promising immediate therapeutic results in the treatment of thoracic aortic pathologies involving the aortic arch. Our study demonstrates that the technique is feasible and produces acceptable results. Long-term outcomes are required for further refinement of this technical approach to confirm technical success and durability over time as a valuable option for endovascular aortic arch repair in specialized centers.

CLINICAL IMPACT

Our short- and mid-term outcomes of physician-modified endografts in 173 patients showed promising results compared to other branched/fenestrated techniques and backed up the endovascular repair of the aortic arch. Meanwhile, the technical expertise pointed out in our manuscript, including preloaded guidewire, diameter-reducing wire and inner mini-cuffs, provided reference and technical guidance for our peers. Most importantly, it demonstrated that the PMEG, as a device whose components were all commercially available, might be a better option for emergency surgery and for centers who had no access to custom-made devices.

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

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

[Secondary ruptures of an abdominal aortic aneurysm treated with a physician-modified fenestrated endograft, endoanchors and finally with open repair]

Secondary rupture is a late complication of endovascular aneurysm repair (EVAR). Open surgery is a technically feasible treatment option in most cases, however, late conversion carries a significant risk of morbidity and mortality, as it usually requires at least partial explantation of the in situ device, which is of major concern especially if suprarenal fixation is present. Endovascular treatment of these cases is usually challenging, especially since the custom-made devices that are often needed are not readily available but having a production time of several weeks. To overcome this limitation, physician-modified stent grafts are getting accepted to treat such urgent cases. We present the case of a patient receiving EVAR who later experienced two ruptures, treated first with a physician-modified endograft and adjunctive endoanchoring, later with open ligation of the lumbar arteries. Orv Hetil. 2023; 164(36): 1426-1431.

Physician-Modified Endovascular Graft for Left Subclavian Artery Fenestration during Thoracic Endovascular Aortic Repair

BACKGROUND

This study aimed to evaluate the safety and efficacy of physician-modified endovascular graft for preservation of left subclavian artery during thoracic endovascular aortic repair.

METHODS

From June 2019 to October 2022, 66 patients with a variety of thoracic aortic pathologies were treated with thoracic endovascular aortic repair using physician-modified endovascular graft left subclavian artery fenestration to achieve adequate proximal landing zone. The details of surgical techniques were described. The perioperative morbidity, mortality, and the outcomes of mid-term follow-up were analyzed.

RESULTS

Of the 66 patients (men: women, 53:13; age, 55.18 [55.18 ± 10.62] years), 53 (80.30%) presented with type B aortic dissection, 10 (15.15%) with thoracic penetrating aortic ulcer, 2 (3.03%) with thoracic aortic aneurysm, and 1 (1.52%) with left subclavian artery aneurysm. All of them underwent thoracic endovascular aortic repair using physician-modified endovascular graft left subclavian artery fenestration on the sterile back table. The technique success rate was 96.97% (n = 64). Total operation time was 92 min (interquartile range, 86-118), graft modification time was 19 min (interquartile range, 17-21), fluoroscopy time was 49 min (interquartile range, 41-62), and contrast agent dosage was 165 mL (interquartile range, 155-185). 30-day perioperative morbidities were 3 (4.55%) strokes, 1 (1.52%) retrograde type A aortic dissection, 1 (1.52%) aortic intimal intussusception, 1 (1.52%) left arm ischemia, and 3 (4.55%) type Ia endoleaks. Postoperative 30-day mortality and reintervention rates were 1.52% and 4.55%, respectively. Among the 63 patients included in the follow-up of 17 months (interquartile range, 7.75-18.25), the primary patency of left subclavian artery fenestration stents was 100%. Late complications were 1 (1.59%) distal stent graft-induced new entry and 1 (1.59%) death due to retrograde type A aortic dissection during the follow-up. The stent graft-induced new entry patient was observed with stable false lumen.

CONCLUSIONS

Thoracic endovascular aortic repair with physician-modified endovascular graft for left subclavian artery revascularization is a safe, feasible, and efficacious technique associated with high success rate. Further study is needed for long-term outcome investigation.

Mechanical Comparison between Fenestrated Endograft and Physician-Made Fenestrations

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Endovascular Options for the Ascending Aorta and Aortic Arch - A Scoping Review

The gold standard for aneurysmal repair of the ascending aorta and the aortic arch has been open surgery with an established track record of good results in suitable patients. In recent years, with innovations in the endovascular field alternative endovascular solutions for pathologies of the aortic arch and ascending aorta became available. At first reserved only for highly selected patients unfit for open surgery, endovascular aortic arch repair is now being offered to patients with suitable anatomy in high volume referral centers after discussion in an interdisciplinary team. The present scoping review aims at providing an overview on indications, available devices, technical aspects and feasibility studies of endovascular arch repair both in elective and emergent situations, including also experiences and considerations from our center.

Midterm Outcomes of Antegrade In Situ Laser Fenestration of Polyester Endografts for Urgent Treatment of Aortic Pathologies Involving the Visceral and Renal Arteries

OBJECTIVE

Aortic endografting and antegrade in situ laser fenestration of visceral arteries (LFEVAR) may be considered as an alternative to open surgery for the emergency repair of complex abdominal aortic aneurysms (AAA) in fragile patients. The aim of this article was to evaluate the midterm results of LFEVAR performed with polyester endografts.

METHODS

From August 2015 to December 2020, all consecutive LFEVAR performed for non-deferrable treatment of complex AAA were analysed. Polyester endografts were deployed and subsequently fenestrated using an atherectomy laser probe; the fenestrations were enlarged using cutting and semicompliant balloons before implantation of balloon expandable bridging stents into the target vessels. Prospectively collected midterm survival, patency, and re-intervention rates were analysed.

RESULTS

Forty four procedures were performed for 11 type 1a endoleaks, five thoraco-abdominal aneurysms, 20 pararenal aneurysms, four segmental renal artery (RA) preservations, three anastomotic aneurysms, and one aortic dissection. One hundred and eight laser fenestrations were performed (26 for the superior mesenteric artery [SMA], 13 for the coeliac trunk, 33 and 31 for the right and left RA, respectively). The median ischaemia duration was 7, 48, 48, and 45 minutes, respectively. The technical success rate was 97%, with no open surgical conversions. The 30 day mortality was 4.5% (n = 2). No spinal cord ischaemia events were observed nor early stent related complications. Kaplan-Meier overall survival at two years was 73%, the aortic related re-intervention free survival was 70%, and the stent related re-intervention free survival was 90.6%. Four target vessel thromboses were detected, of which three were rescued. Three type IIIc endoleaks, one RA false aneurysm, and one SMA stenosis, required re-intervention during a median follow up of 24.7 months.

CONCLUSION

Antegrade LFEVAR is feasible, safe, and provides satisfactory early and midterm outcomes for non-deferrable treatment of aortic pathologies involving the visceral segment. Long term data are mandatory to confirm the usefulness of this promising off label technique.

Mechanical Performance Assessment of Physician Modified Aortic Stent Graft

OBJECTIVE

This study aimed to compare various fenestration configurations of physician modified aortic stent grafts in order to identify which design parameters have a significant influence on the mechanical behaviour of the fenestration.

METHODS

the fenestration configurations were considered according to different manufacturing parameters: cutting technique, fenestration reinforcement, suture material, reinforcement loop design, and number of suture points. The performance of the graft/bridging stent assembly was assessed at various levels: (1) branch pull out force; (2) fenestration enlargement and rupture strength; (3) balloon angioplasty resistance; and (4) behaviour under cyclic fatigue.

RESULTS

Sixty manual fenestrations were created. The tests performed on the fenestrations had several main findings. First, reinforcement increased the radial force on the branch, which increased the pull out force; this may limit migration of the bridging stent in vivo. The phenomenon was amplified with a snare reinforced fenestration, which seemed to be the most efficient. Moreover, increasing the number of suture passes also appeared to increase the branch extraction force securing the assembly. The enlargement tests showed that non-reinforced fenestrations had the weakest radial strength. This was confirmed with the balloon angioplasty test, which showed that these latter specimens undergo the most significant textile degradation. After fatigue tests, all fenestrations were larger, showing that elastic recoil was incomplete in all samples. The largest recoil was observed in the non-reinforced ophthalmological cautery (OC) fenestrations (40%). Regarding the behaviour of the samples up to rupture, all samples behaved in a similar way; however, the double loop fenestration strength level was the highest.

CONCLUSION

This study demonstrated that the snare double loop reinforcement has an advantage regarding durability of the graft branch assembly. Moreover, non-reinforced fenestrations show signs of weakness and lack of stability, which questions the in situ or laser fenestration procedures.

Monocentric Evaluation of Physician-Modified Fenestrations or Parallel Endografts for Complex Aortic Diseases

PURPOSE

This study aimed to investigate the demographic and anatomic characteristics, as well as perioperative and follow-up results of fenestration and parallel techniques for the endovascular repair of complex aortic diseases.

MATERIALS AND METHODS

A retrospective study was conducted on 67 consecutive patients underwent endovascular treatment for complex aortic diseases including abdominal aortic aneurysm (AAA), thoracoabdominal aneurysm (TAAA), aortic dissection, or prior endovascular repair with either fenestrated and parallel endovascular aortic repair (f-EVAR or ch-EVAR) at a single institute from 2013 to 2021. Choices of intervention were made by the disease' emergency, patients' general condition, the anatomic characteristics, as well as following the recommendation from the devices' guidelines. Patients' clinical demographics, aortic disease characteristics, perioperative details, and disease courses were discussed. Short- and mid-term follow-up results were obtained and analyzed. Endpoints were aneurysm-related and unrelated mortality, branch instability, and renal function deterioration.

RESULTS

Totally, 34 and 27 patients received f-EVAR and ch-EVAR, while 6 patients received a combination of both. Fenestrated endovascular aortic repair was conducted mainly in AAA affecting visceral branches and TAAA, whereas ch-EVAR was normally utilized for infrarenal AAA. Regarding the average number of reconstructed arteries per patient, there was a significant difference among f-EVAR, ch-EVAR, and the combination group (mean = 2.3 ± 0.9, 1.4 ± 0.6, 3.5 ± 0.5, p<0.001). Primary technical success was achieved in 28 (82.4%), 22 (81.5%), and 3 (50.0%) patients for each group. Besides operational time (5.77 ± 2.58, 4.47 ± 1.44, p=0.033), no significant difference was observed for blood transfusion, intensive care unit (ICU) or hospital stay, blood creatinine level, 30-day complications, or follow-up complications between patients undergoing f-EVAR or ch-EVAR. Patients receiving combination of both techniques had a higher rate of blood transfusion (p=0.044), longer operational time (p=0.008) or hospital stay (p=0.017), as well as more stent occlusion (p=0.001), endoleak (p=0.004) at short-term and a higher rate of endoleak (p=0.023) at mid-term follow-up.

CONCLUSION

In conclusion, this study demonstrated that f-EVAR and ch-EVAR techniques had acceptable perioperative and follow-up results and should be considered viable alternatives when encountering complex aortic diseases.

CLINICAL IMPACT

This study sought to investigate the baseline and pathological characteristics, as well as perioperative and follow-up results of f-EVAR and ch-EVAR at a single Chinese institution. F-EVAR (mostly physician-modified f-EVAR) was applied in patients with a wide range of etiologies and disease types, while ch-EVAR was preferred for AAA in older patients with an average higher ASA grade. Our experience suggested acceptable safety and efficacy both for techniques, and no significant difference was observed between the two groups regarding any short or mid-term adverse events.

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

BACKGROUND

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.

METHODS

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 >70 mm. Ruptured aneurysms were excluded.

RESULTS

Thirty-three patients (mean age: 74 +/- 11 years) were included. The mean aneurysm diameter was 76 +- 20 mm. 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 31 months (1-79). Overall survival estimates were 81.4% (95% confidence interval [CI]: 63.1.-91.2) at 1 year and 71.6% (95% CI: 52.6-84.1) at 2 years. Freedom from reintervention rates at 1 and 2 years 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 2 years were 99.2% (95% CI: 94.2-99.9) and 97.7% (95% CI: 90.7-99.4).

CONCLUSIONS

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.

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.

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.

Effects of Sterilization Methods on Different 3D Printable Materials for Templates of Physician-Modified Aortic Stent Grafts Used in Vascular Surgery-A Preliminary Study

Three-dimensionally-printed aortic templates are increasingly being used to aid in the modification of stent grafts in the treatment of urgent, complex aortic disorders, often of an emergency nature. The direct contact between the aortic template and the stent graft implies the necessity of complete sterility. Currently, the efficacy of sterilizing aortic templates and the effect of sterilization on the geometry of tubular aortic models are unknown. A complex case of aortic arch dissection was selected to prepare a 3D-printed aortic arch template, which was then manufactured in six popular printing materials: polylactic acid (PLA), nylon, polypropylene (PP), polyethylene terephthalate glycol (PETG), and a rigid and flexible photopolymer resin using fused deposition modeling (FDM) and stereolithography (SLA). The 3D models were contaminated with Geobacillus stearothermophilus broth and Bacillus atrophaeus. The sterilization was performed using three different methods: heat (105 °C and 121 °C), hydrogen peroxide plasma, and ethylene oxide gas. Before and after sterilization, the aortic templates were scanned using computed tomography to detect any changes in their morphology by comparing the dimensions. All sterilization methods were effective in the elimination of microorganisms. Steam sterilization in an autoclave at 121 °C caused significant deformation of the aortic templates made of PLA, PETG, and PP. The other materials had stable geometries, and changes during mesh comparisons were found to be submillimeter. Similarly, plasma, gas, and heat at 105 °C did not change the shapes of aortic templates observed macroscopically and using mesh analysis. All mean geometry differences were smaller than 0.5 mm. All sterilization protocols tested in our study were equally effective in destroying microorganisms; however, differences occurred in the ability to induce 3D object deformation. Sterilization at high temperatures deformed aortic templates composed of PLA, PETG, and PP. This method was suitable for nylon, flexible, and rigid resin-based models. Importantly, plasma and gas sterilization were appropriate for all tested printing materials, including PLA, PETG, PP, nylon, flexible and rigid resins. Moreover, sterilization of all the printed models using our novel protocol for steam autoclaving at 105 °C was also 100% effective, which could represent a significant advantage for health centers, which can therefore use one of the most popular and cheap methods of medical equipment disinfection for the sterilization of 3D models as well.

Treatment of a Delayed Type IIIb Endoleak 20 Years Post EVAR With Inverted Contralateral Limb Custom-Made Device: A Case Report

PURPOSE

Type III endoleak can be difficult to distinguish from Type I endoleak. Depending on the stent graft anatomy, the use of standard bifurcated endografts may not be technically feasible, and patients may have to be subject to an aorto-uni-iliac repair with femoral-femoral bypass or open surgery.

CASE REPORT

We report a case of an 86-year-old male who had a Type IIIb endoleak 20 years post EVAR which was characterized on angiography to be from a hole close to the bifurcation limb origin. The initial Talent (Medtronic, Santa Rosa, California) device had a 50 mm main body common trunk, which was not amenable to treatment with standard devices. He was successfully treated with a custom-made device with an inverted contralateral limb.

CONCLUSIONS

Our case highlights the need for lifelong surveillance post EVAR as endoleak may present decades post initial EVAR. It also demonstrates that many Type III endoleak which were otherwise deemed unsuitable for treatment with standard devices may potentially be treatable with custom-made device (CMD). This solution preserves a percutaneous option in a now older person which avoids surgical bypass. Further studies are required to establish the durability of this treatment and survey for recurrence.

The accuracy and reliability of 3D printed aortic templates: a comprehensive three-dimensional analysis

Background

Advances in 3D printing technology allow us to continually find new medical applications. One of them is 3D printing of aortic templates to guide vascular surgeons or interventional radiologists to create fenestrations in the stent-graft surface for the implantation procedure called fenestrated endovascular aortic aneurysm repair. It is believed that the use of 3D printing significantly improves the quality of modified fenestrated stent-grafts. However, the accuracy and reliability of personalized 3D printed models of aortic templates are not well established.

Methods

Thirteen 3D printed templates of the visceral aorta and sixteen of the aortic arch and their corresponding computer tomography of angiography images were included in this accuracy study. The 3D models were scanned in the same conditions on computed tomography (CT) and evaluated by three physicians experienced in vascular CT assessment. Model and patient CT measurements were performed at key landmarks to maintain quality for stent-graft modification, including side branches and aortic diameters. CT-scanned aortic templates were segmented, aligned with sourced patient data, and evaluated for the Hausdorff matrix. Next, Bland-Altman plots determined the degree of agreement.

Results

The Intraclass Correlation Coefficients values were more than 0.9 for all measurements of aortic diameters and aortic branches diameter in all landmark locations. Therefore, the reliability of the aortic templates was considered excellent. The Bland-Altman plots analysis indicated measurement biases of 0.05 to 0.47 for aortic arch templates and 0.06 to 0.38 for reno-visceral aortic templates. The arithmetic mean of Hausdorff's mean distances of the aortic arch templates was 0.47 mm (SD =0.06) and ranged from 0.34 to 0.58. The mean metrics for abdominal models was 0.24 mm (SD =0.03) and ranged from 0.21 to 0.31.

Conclusions

The printed models of 3D aortic templates are accurate and reliable, thus can be widely used in endovascular surgery and interventional radiology departments as aortic templates to guide the physician-modified fenestrated stent-graft fabrication.

Parallel grafts and physician modified endografts for endovascular repair of the aortic arch

Aortic arch aneurysms are a challenging clinical problem especially in high-risk patients. Open aortic arch replacement, even in the best of centers, carries significant risk of stroke or death in this high-risk population. Many high-risk patients are deemed inoperable and not offered repair. Branched and fenestrated thoracic endografts are currently undergoing clinical trials in the United States but are not yet commercially available. Many elderly and frail patients have significant brachiocephalic occlusive disease or anatomy excluding them for consideration for such clinical trials. These patients also present with acute aortic syndromes requiring urgent or emergent repair and are unable to participate in clinical trials due to the time required to have such devices available. Alternative endovascular therapies, including parallel stent grafts (including Chimneys, Snorkels and Periscopes) and physician modified thoracic endografts, have been used to treat such high-risk patients combined with commercially available thoracic endovascular aneurysm repair (TEVAR) devices. This paper aims to review the techniques and current reported outcomes from parallel stent grafts and physician modified devices used to treat high risk patients undergoing repair for aortic arch pathologies.

Early and mid-term durability of surgeon-modified and custom-made fenestrated devices for the treatment of complex aortic pathology

OBJECTIVE

Fenestrated endovascular aneurysm repair (F-EVAR) has allowed successful treatment of patients with complex aortic aneurysms. Custom-made devices (CMDs) are manufactured by companies and tailored to the patient's anatomy to incorporate target vessels, while there is also the "off label" alternative with the devices modified by a surgeon in the operating room: surgeon-modified FEVAR (sm-FEVAR). This study aims to present and compare technical durability of CMDs- and sm-FEVAR for complex abdominal and thoracoabdominal aortic pathologies.

METHODS

A retrospective cohort study was undertaken including all consecutive patients treated with sm- or CMD-FEVAR during a 3-year period in a single centre. Only cases with at least three reno-visceral target vessels were included. Primary outcomes were technical success, and freedom from endoleak (EL) (Ia or III; all branch related) and re-intervention during follow-up period. Mortality and morbidity were also recorded.

RESULTS

32 sm-FEVAR patients (81,3% male) and 79 CMD-FEVAR patients (77,2% male) were included. Indication for sm-FEVAR was exclusively urgent, while all CMD- FEVAR were elective. Technical success was similar in sm-FEVAR (100%) and CMD-FEVAR (98,7%) (p=0.523). Mean follow-up was 16.3±13 and 20±17.3 months for sm-FEVAR and CMD- FEVAR, respectively (p=0.28). The freedom from EL Ia rate was 91.7% [standard error (SE) 5.7%] at 12 months in sm-FEVAR, while it was 97.7% (SE 2.2%) and 92.3% (SE 4.3%) at 12 and 24 months, respectively in CMD-FEVAR (p=0.69). The freedom from EL III rate was 95.5% (SE 4.4%) and 88% (SE 8.2%) at 12 and 24 months, respectively in sm-FEVAR, while it was 92.1% (SE 3.8%) and 89.2% (SE 4.7%) at 12 and 24 months, respectively in CMD-FEVAR (p=0.68). The freedom from re-intervention rate was 91.6% (SE 5.7%) and 84.6% (SE 8.6%) at 12 and 24 months, respectively in sm-FEVAR, while it was 91.7% (SE 4%) and 83.4% (SE 5.9%) at 12 and 24 months, respectively in CMD-FEVAR (p=0.90). The survival rate was 87.5% (5.8%) and 76.3% (7.9%) at 1 and 12 months, respectively in sm-FEVAR, while it was 93.7% (2.7%) at 1 month in CMD-FEVAR without any other death during FU period. No bridging stent occlusions were noted during follow up period in any patient.

CONCLUSION

Sm-FEVAR offers good technical success and mid-term clinical outcomes in urgent cases of complex aortic pathologies. Its durability is acceptable and comparable to CMD-FEVAR with a relatively low re-intervention rate.

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

INTRODUCTION

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.

RESULTS

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).

CONCLUSION

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.

[Surgeon-modified Stent Grafts for Complex Aortic Reconstructions - What is Feasible?]

BACKGROUND

The close anatomical relationship to the visceral vessels renders the treatment of complex throacoabdominal aortic pathologies challenging. In emergent cases, off-the-shelf stent grafts and parallel techniques are feasible treatment options. Alternatively, the treating surgeon can alter a conventional stent graft, creating a so-called surgeon-modified stent graft (SMSG) to adapt it to the complex aortic pathology. The aim of this publication is to present the possibilities and results of this method.

RESULTS

The location of SMSG's fenestrations can be determined after manual measurements of the centerline of flow reconstructions of the aortic computed tomography-angiography. The planning of the SMSG can be simplified and standardized by creating personalized 3D aortic models, and by using algorithms for the automated determination of the ideal fenestration positions. Most approved stent grafts can be used as platforms for SMSG. Different manufacturing techniques have been described. In addition to simple fenestrations, mini-cuffs, directional branches, and inner branches are used. Furthermore, diameter reducing ties and preloaded catheters could facilitate the implantation. The treatment of complex aortic pathologies using SMSG has achieved good results, with high technical success rate of 90-100%, and low 30-day mortality, especially when compared to open surgical treatment of similar patients. The rate of endoleak of 0-14% was also acceptable. Long-term durability results after treatment with SMSG are not yet available.

CONCLUSION

Surgeon-modified stent grafts are safe and feasible for the endovascular treatment of patients with urgent complex thoracoabdominal aortic pathologies. They represent compassionate use and show promising results in the published literature.

Thoracic Endovascular Repair for Aortic Arch Pathologies with Surgeon Modified Fenestrated Stent Grafts: A Multicentre Retrospective Study

OBJECTIVE

To evaluate the outcome of thoracic endovascular repair (TEVAR) for aortic arch pathologies with surgeon modified fenestrated stent grafts.

METHODS

A multicentre, retrospective study consisting of consecutive patients from seven centres treated with surgeon modified fenestrated stent grafts for aortic arch pathologies was conducted. A technique to align fenestrations and supra-aortic vessels was applied. Rates of technical success, mortality, complications, and re-interventions were evaluated.

RESULTS

Between February 2016 and January 2020, 513 consecutive patients with aortic arch pathologies received TEVAR with surgeon modified fenestrated stent grafts. The technical success rate was 98.6% (n = 506). In total, 626 fenestrations were created to revascularise 684 branch arteries of the aortic arch. There were 13 deaths and 15 re-interventions within 30 days of the operation. The estimated clinical success rate at 30 days was 94.4% (95% confidence interval [CI] 92.4 - 96.4), the estimated survival at 30 days was 97.5% (95% CI 96.1 - 98.9), and the estimated freedom from re-intervention at 30 days was 97.1% (95% CI 95.7 - 98.5). The median follow up was 27 (interquartile range 13 - 31) months. During follow up, there were five aortic related deaths, three non-aortic related deaths, and four deaths of unknown cause. Eighteen patients underwent re-intervention. The estimated clinical success rate at 24 months was 88.2% (95% CI 85.5 - 91.0), the estimated survival at 24 months was 94.9% (95% CI 92.7 - 97.1), and the estimated freedom from re-intervention at 24 months was 93.1% (95% CI 91.0 - 95.3). In total, 18 cases of stroke were recorded, including 12 within 30 days and six during follow up; six cases of retrograde type A aortic dissection were recorded, including five within 30 days and one during the follow up.

CONCLUSION

TEVAR with surgeon modified fenestrated stent grafts for the treatment of aortic arch pathologies provides acceptable outcomes. Further follow up is required to confirm the benefits of this approach.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2

OBJECTIVES

To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair.

METHODS

A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed.

RESULTS

Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively.

CONCLUSIONS

The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

Clinical application and technical details of cook zenith devices modification to treat urgent and elective complex aortic aneurysms

Purpose

To describe technical details of modifying four different Cook Zenith devices to treat complex aortic aneurysms.

Material

In the first three cases, the modification process involved complete stent graft deployment on a sterile back table. Fenestrations were created using an ophthalmologic cautery and reinforced with a radiopaque snare using a double-armed 4–0 Ethibond locking suture based on measurements obtained on centerline of flow. In each instance, a nitinol wire was withdrawn and redirected through and through the fabric and used as a constraining wire. In the fourth patient, modification involved partial stent graft deployment and creation of additional two fenestrations to accommodate renal arteries. The devices are resheathed and implanted in the standard fashion.

Results

Four patients underwent exclusion of their aneurysms, including thoracoabdominal aneurysms (n = 2), a contained ruptured juxtarenal aneurysm (n = 1), and a ruptured failed previous endovascular repair (n = 1). Fifteen fenestrations were successfully bridged with Atrium iCAST stent grafts. Average graft modification time, operative time, contrast volume, radiation dose, estimated blood loss, and hospital length of stay were 89 min, 155.25 min, 58.8 mL, 2451 mGy, 175 mL, and 4.3 days, respectively. One patient required a secondary intervention to treat a type Ib endoleak. During an average follow-up of 25 months, aneurysm sacs progressively shrank without additional intervention.

Conclusion

Physician-modified fenestrated/branched endografts are a safe alternative to custom made devices, especially in urgent cases and should be part of the armamentarium of any complex aortic program.

Hemodynamic Parameters Predict In-stent Thrombosis After Multibranched Endovascular Repair of Complex Abdominal Aortic Aneurysms: A Retrospective Study of Branched Stent-Graft Thrombosis

Background: Branch vessel occlusion is reported in endovascular repair of aortic pathology. This study aimed to evaluate the hemodynamic indicators associated with in-stent thrombosis (IST) of a branched stent-graft (BSG) after endovascular aortic repair (EVAR) of a complex abdominal aortic aneurysm.

Methods: A retrospective evaluation was performed based on the computed tomography (CT) scans and clinical data of three patients who underwent multi-branched endovascular repair. Patient-specific 3-dimensional models were reconstructed, and hemodynamic analysis was performed for IST. Hemodynamics-related parameters including time-averaged wall shear stress (TAWSS), oscillatory shear stress index (OSI), and relative residence time (RRT) were compared among the individual patients.

Results: The flow velocity, TAWSS, OSI, and RRT were radically changed in the area of the IST. In BSGs, IST tended to occur in the regions of hemodynamic alteration near the bends in the device, where a decreased flow velocity (<0.6 m/s) and TAWSS (<0.8 Pa) and an elevated OSI (>0.2) and RRT (>5 s) were consistently observed.

Conclusions: Hemodynamic perturbations in BSGs cause a predisposition to IST, which can be predicted by a series of changes in the flow parameters. Early hemodynamic analysis might be useful for identifying and remediating IST after multibranched endovascular repair.