Systematic Review on the Use of 3D-Printed Models for Planning, Training and Simulation in Vascular Surgery.

The use of 3D-printed models in simulation-based training and planning for vascular surgery is gaining interest. This study aims to provide an overview of the current applications of 3D-printing technologies in vascular surgery. We performed a systematic review by searching four databases: PubMed, Web of Science, Scopus, and Cochrane Library (last search: 1 March 2024). We included studies considering the treatment of vascular stenotic/occlusive or aneurysmal diseases. We included papers that reported the outcome of applications of 3D-printed models, excluding case reports or very limited case series (≤5 printed models or tests/simulations). Finally, 22 studies were included and analyzed. Computed tomography angiography (CTA) was the primary diagnostic method used to obtain the images serving as the basis for generating the 3D-printed models. Processing the CTA data involved the use of medical imaging software; 3DSlicer (Brigham and Women's Hospital, Harvard University, Boston, MA), ITK-Snap, and Mimics (Materialise NV, Leuven, Belgium) were the most frequently used. Autodesk Meshmixer (San Francisco, CA, USA) and 3-matic (Materialise NV, Leuven, Belgium) were the most frequently employed mesh-editing software during the post-processing phase. PolyJet™, fused deposition modeling (FDM), and stereolithography (SLA) were the most frequently employed 3D-printing technologies. Planning and training with 3D-printed models seem to enhance physicians' confidence and performance levels by up to 40% and lead to a reduction in the procedure time and contrast volume usage to varying extents.

The Role of Narrow Aortic Bifurcation in Affecting EVAR Treatment and Outcomes.

BACKGROUND: The narrow aortic bifurcation (NAB) is considered a risk factor for endograft thrombosis after aorto-biiliac endovascular aneurysm repair (EVAR) for aortic or iliac aneurysm. Nowadays, no consensus on the threshold diameter for the definition of NAB is reached and other aortic bifurcation features are rarely considered. The aim of the study is to assess the EVAR outcomes using bifurcated endograft according to anatomical characteristics of aortic bifurcation. METHODS: The study included patients treated with primary EVAR from 2016 to 2022. A retrospective analysis of single-center prospectively collected database was performed. Patients were classified in standard aortic bifurcation (SAB) (aortic bifurcation diameter >20 mm), NAB (≤20 mm and >16 mm), and extremely NAB (eNAB) (≤16 mm). The 3 groups were compared in terms of patient demographics, risk factors, procedure setting (elective or urgent/emergent), and type of deployed endograft. In NAB and eNAB groups, severe calcification (SC) and length of stenotic aortic bifurcation >10 mm (long-NAB) were assessed from preoperative imaging. In SAB, NAB, and eNAB groups, following outcomes were evaluated: rate of intraoperative iliac endograft stenting (unilateral or kissing stenting), primary patency (PP), freedom from endograft-related reintervention, and overall survival during follow-up. RESULTS: The total number of deployed aorto-biiliac endografts was 365 (mean age: 76.6 ± 7.4 years; male 89.3%): SAB 298 (81.6%), NAB 57 (15.6%), and eNAB 10 (2.7%) cases. Female gender, chronic obstructive pulmonary disease patients, and active smokers were more frequent in patients with smaller aortic bifurcation diameter (P = 0.002, 0.039, and 0.010, respectively). In NAB and eNAB groups, SC was reported in 18/67 cases (26.9%) and long-NAB in 15/67 cases (25.4%). Patients with eNAB have more frequent SC of aortic bifurcation (60% vs. NAB 21.1%, P = 0.018) and long-NAB (50% vs. NAB 17.5%, P = 0.023). In SAB, NAB, and eNAB, intraoperative iliac endograft stenting was performed in 34/298 (11.4%), 9/57 (15.8%), and 5/10 (50%), respectively (P = 0.001). Kissing stenting was performed more frequently in groups with smaller aortic bifurcation diameter (P = 0.010). Mean follow-up was 30.2 ± 21.5 months. At 1, 3, and 5 years, PP was 98.5%, 96.6%, and 95.6%, respectively. eNAB had lower rate of PP compared to NAB group (P = 0.030). Long-NAB had lower rate of PP (P = 0.035). At 1, 3, and 5 years, endograft-related reintervention was 96.8%, 86.7%, and 76.7%, respectively, with no differences between 3 groups (P = 0.423). At 1, 3, and 5 years, survival was 92.5%, 77.6%, and 58.1%, respectively, with no difference between SAB, NAB, and eNAB (P = 0.673). CONCLUSIONS: Female gender, chronic obstructive pulmonary disease patients, and active smokers have more frequently smaller aortic bifurcation diameter. eNAB patients have more challenging anatomical characteristics compared with NAB group, requiring higher rate of intraoperative stenting, especially kissing stenting. Mid-term PP seems to be negatively influenced by aortic bifurcation ≤16 mm and long-NAB.

Systematic review and meta-analysis of incidence, indications, and outcomes of early open conversions after EVAR for abdominal aortic aneurysms.

INTRODUCTION: The purpose of this study is to report incidence, indications, and outcomes of early open conversions (EOC) after endovascular aortic repair (EVAR), defined as surgical conversion performed within 30 days from the initial EVAR. EVIDENCE AQUISITION: A systematic review of the literature was performed (database searched: PubMed, Web of Science, Scopus, Cochrane Library; last search April 2023). Articles reporting EOC after EVAR comprising at least five patients were included. Meta-analyses of proportions were performed using a random-effects model. EVIDENCE SYNTHESIS: Seventeen non-randomized studies, published between 1999 and 2022, were included. A total of 35,970 patients had previously undergone EVAR, of these 438 patients underwent EOC. Estimated incidence of EOC was 1.4% (95% CI 1.1-1.4; I2=81.66%). Specifically, in the works published before 2010 the incidence was 1.8% (95% CI 1.3-2.4; I2=74.25) while for subsequent ones it was 0.9% (95% CI 0.6-1.1; I2=69.82). Weighted mean age was 74.91 years (95% CI 72.42-77.39; I2=83.11%). Estimated rate of cause determining EOC were: access issue in 27.7% of patients (95% CI 13.8-41.6; I2=88.14%), incorrect placement of the endograft in 20.1% (95% CI 10.2-30.0; I2=76,9%), problems with "delivery system" in 9.0% (95% CI 4.9-13.1; I2=0%), aorto-iliac rupture in 8.6% (95% CI 4.5-12.6; I2=0%), endoprosthesis migration in 7.9% of cases (95% CI 3.3-12.4; I2=22.96%), failure in engaging the contralateral gate in 4.8% (95% CI 1.6-8; I2=0%), "kinking" or "twisting" of endoprosthesis in 3.3% (95% CI 0.6-5.9; I2=0%), graft thrombosis in 3.2% (95% CI 0.6-5.7; I2=0%), type Ia endoleak in 2.9% (95% CI 0.4-5.4; I2=0%), type III endoleak in 2.8% (95% CI 0.3-5.3; I2=0%) and endograft infection in 2.7% (95% CI 0.3-5.2; I2=0%). Intraoperative conversion rate was 91.1% (95% CI 85.8-96.4; I2=66.01%). Early mortality rate after EOC was 14.5% (95% CI 9.1-19.9; I2=48.31%). Mean length of stay (LOS) was 11.94 days (95% CI 6.718-17.172; I2=92.34%). CONCLUSIONS: The incidence of EOC seems to decrease over time. Causes of EOC were mainly related to access problems and incorrect positioning of the endograft. Most of the EOC were performed intraoperatively carrying a high mortality rate.

Acute Type B Aortic Dissection Complicated With Spinal Cord Ischemia and Paraplegia Treated With Endovascular Scissor Technique.

Spinal cord ischemia leading to paraplegia is a rare, life-limiting complication of acute type B aortic dissection. We report a case of spinal cord ischemia occurred in a young woman treated with endovascular scissor technique in urgent setting. The patient had an uneventful post-procedural course. After 4 months, computed tomography angiography confirmed false lumen reperfusion and major symptoms were regressed. In selected cases, this procedure is a tool to improve false lumen perfusion in type B dissections, and demonstrated to be helpful in our case of spinal cord ischaemia.

Systematic Review and Meta-Analysis of the Outcome of Different Treatments for Innominate Artery Stenosis or Occlusion.

The present study reported the outcomes of different treatments for innominate artery (IA) atherosclerotic stenosis or occlusion. We performed a systematic review of the literature (4 database searched; last search February 2022), including articles with ≥5 patients. We performed meta-analyses of proportions for different postoperative outcomes. Fourteen studies were included (656 patients; 396 underwent surgery, 260 endovascular procedures). IA lesions were asymptomatic in 9.6% (95% CI 4.6-14.6). Overall estimated technical success (TS) rate was 91.7% (95% CI 86.9-96.4); weighted TS rate was 86.8% (95% CI 75-98.6) in the surgical group (SG), 97.1% (95% CI 94.6-99.7) in the endovascular group (EG). Postoperative stroke in SG was 2.5% (95% CI 1-4.1) and 2.1% in EG (95% CI .3-3.8). Overall, 30-day occlusion was estimated .9% (95% CI 0-1.8) in SG and .7% (95% CI 0-1.7) in EG. Thirty-day mortality was 3.4% (95% CI .9-5.8) in SG and .7% (95% CI 0-1.7) in EG. Estimated mean follow-up after intervention was 65.5 months (95% CI 45.5-85.5) in SG and 22.4 months (95% CI 14.72-30.16) in EG. During follow-up, restenosis in SG were 2.8% (95% CI .5-5.1) and 16.6% (95% CI 5- 28.1) in EG. In conclusion, the endovascular approach seems to offer good short to mid-term outcomes, but with a higher rate of restenosis during follow-up.