Endovascular Aneurysm Repair Procedures Research Articles

Fluoroscopically guided vascular and cardiac transcatheter procedures: a comparison of occupational and patient dose by anatomical region

X-ray guided procedures are being performed by an increasing variety of medical specialties. Due to improvements in vascular transcatheter therapies, there is an increasing overlap of imaged anatomy between medical specialties. There is concern that non-radiology fluoroscopic operators may not have sufficient training to be well informed of the potential implications of radiation exposure and mitigation strategies to reduce dose. This was a prospective, observational, single center study to compare occupational and patient dose levels when imaging different anatomical regions during fluoroscopically guided cardiac and endovascular procedures. Occupational radiation dose was measured at the level of the temple of 24 cardiologists and 3 vascular surgeons (n = 1369), 32 scrub nurses (n = 1307) and 35 circulating nurses (n = 885). The patient dose was recorded for procedures (n = 1792) performed in three angiography suites. Abdominal imaging during endovascular aneurysm repair (EVAR) procedures was associated with a comparatively high average patient, operator and scrub nurse dose despite additional table-mounted lead shields. Air kerma was relatively high for procedures performed in the chest, and chest + pelvis. Higher dose area product and staff eye dose were recorded during procedures of the chest + pelvis due to the use of digital subtraction angiography to evaluate access route prior to/during transaortic valve implantation. Scrub nurses were exposed to higher average radiation levels than the operator during some procedures. Staff should be cognizant of the potentially higher radiation burden to patients and exposed personnel during EVAR procedures and cardiac procedures using digital subtraction angiography.

BMI-Based organ doses in endovascular aneurysm repair interventions utilising Monte Carlo simulation

In this study, the effect of body-mass-index (BMI) on organ doses (ODs) during infrarenal endovascular-aneurysm-repair (EVAR) procedures was evaluated. Patient- and intra-operative data from fifty-nine EVAR procedures were inserted into VirtualDose-IR software to calculate ODs. For overweight, obesity class-I and obesity class-II, ODs were up to 147%, 412% and 775% higher than those for normal weight-patients, respectively. A large variation was observed in ODs published in literature mainly due to the differences in the software and the technical parameters used for the calculations.

18F]FDG Uptake in Non-Infected Endovascular Grafts: A Retrospective Study.

Purpose: After endovascular aneurysm repair (EVAR), an increased [18F]FDG uptake may be observed at PET/CT, being common to both vascular graft/endograft infection (VGEI) and sterile post-surgical inflammation. Increased non-specific metabolic activity, due to foreign body reaction, can persist for several years after surgery, thus complicating the interpretation of PET/CT studies. In this paper, we aimed to assess [18F]FDG distribution at different time-points after the implant of abdominal Endurant® endografts in patients without suspicion of infection. Methods: We retrospectively evaluated [18F]FDG/CT in 16 oncological patients who underwent abdominal aortic aneurysm exclusion with Endurant® grafts. Patients had no clinical suspicion of infection and were followed up for at least 24 months after scan. [18F]FDG PET/CT scans were interpreted using both visual and semi-quantitative analyses. Results: The time between the EVAR procedure and [18F]FDG PET/CT ranged between 1 and 36 months. All grafts showed mild and diffuse [18F]FDG uptake without a focal pattern. Mean values of SUVmax were 2.63 ± 0.48 (95% CI 2.38-2.88); for SUVmean 1.90 ± 0.33 (95% CI 1.72-2.08); for T/B ratios 1.43 ± 0.41 (95% CI 1.21-1.65). SUVmax and SUVmean were not correlated to the time elapsed from the procedure, but we observed a declining trend in T/B ratio over time. Conclusions: Endovascular implant of Endurant® grafts does not cause a significant inflammatory reaction. The evidence of faint and diffuse [18F]FDG uptake along the graft can reliably exclude an infection, even in early post-procedural phases. Therefore, in patients with a low probability of VGEI, [18F]FDG PET/CT can also be performed immediately after EVAR.

Frailty Among Veterans Undergoing Abdominal Aortic Aneurysm Repair

Frailty is a known risk factor for adverse outcomes following surgery and affects at least 3 of every 10 US Veterans aged 65years and older. We designed a study to characterize the association between frailty and complications after endovascular aneurysm repair (EVAR) compared to open aneurysm repair (OAR) at our regional Veterans Affairs Medical Center. Veterans who underwent either OAR or EVAR at our institution between January 1, 2000 and December 31, 2020 were identified. We examined medical history, procedure characteristics, perioperative complications, and frailty as measured by the 5-factor modified frailty index (mFI-5). Frailty was defined as an mFI-5 score ≥2. Primary endpoints were postoperative complications, duration of surgery, and length of hospital stay. Tests of association were performed with t-test and chi-squared analysis. Over the 21-year period, we identified 314 patients that underwent abdominal aortic aneurysm (AAA) repair with 115 (36.6%) OAR and 199 EVAR (63.4%) procedures. Patients undergoing EVAR were older on average (72.1years vs. 70.2years) and had a higher average mFI-5 compared to the open repair group (1.49 vs. 1.23, P=0.036). When comparing EVAR and OAR cohorts, patients undergoing OAR had a larger AAA diameter (6.5cm, standard deviation [SD]: 1.5) compared to EVAR (5.5cm, SD: 1.1 P<0.0001). Fewer frail patients underwent OAR (n=40, 34.8%) compared to EVAR (n=86, 43.2%), and frail EVAR patients had higher AAA diameter (5.8cm, SD: 1.0) compared to nonfrail EVAR patients (5.3cm, SD 1.2), P=0.003. Among OAR procedures, frail patients had longer operative times (296min vs. 253min, P=0.013) and higher incidence of pneumonia (17.5% vs. 5.3%, P=0.035). Among frail EVAR patients, operative time and perioperative complications including wound dehiscence, surgical site infection, and pneumonia were not significantly different than their nonfrail counterparts. Overall, frail patients had more early complications (n=55, 43.7%) as compared to nonfrail patients (n=48, 25.5%, P=0.001). OAR patients had higher rates of postoperative complications including wound dehiscence (7.0% vs. 0.5%, P=0.001), surgical site infections (7.0% vs. 1.0%, P=0.003), and pneumonia (9.6% vs. 0.5%, P=<0.0001). Open repair was also associated with overall longer average intensive care unit stays (11.0days vs. 1.6days, P<0.0001) and longer average hospitalizations (13.5days vs. 2.4days, P<0.0001). Our findings demonstrate that frailty is associated with higher rates of adverse outcomes in open repair compared to EVAR. Patients who underwent open repair had higher rates of wound dehiscence, surgical site infection, and pneumonia, compared to those undergoing endovascular repair. Frailty was associated with larger AAA diameter in the EVAR cohort and longer operative times, with higher frequency of postoperative pneumonia in the OAR cohort. Frailty is a strong risk factor that should be considered in the management of aortic aneurysms.

Internal Iliac Artery Embolization within EVAR Procedure: Safety, Feasibility, and Outcome.

This study is focused on Internal Iliac Artery (IIA) embolization in patients undergoing Endovascular Aneurysm Repair (EVAR). Our aims were: to establish the feasibility of the procedure; to assess the presence of endoleak (EL) and increase in the size of the sac at follow-up; to define the need for reintervention; and to evaluate mortality rate. In this retrospective single-center study, EVAR-treated patients with an embolization of IIA were chosen. Coils and vascular plug were used as embolizing agents. A total of 49 participants were enrolled in the study (48 men and one woman) with a median age of 76 ± 12 years. Patients had no early EL in 87.75% of cases, 8.16% had type 1a EL, 2.04% type 1b EL, and 2.04% type 2 EL, with a comprehensive technical success of 95.91%. In the follow-up, at 1 month 72.22% remained without EL, at 6 months 70.97%, and at 1 year 81.48%. In the same period, the trend of type 1 EL was 5.56% (1 month), 3.23% (6 months), and 0% (1 year). For EL type 2: 22.22% at 1 month, 25.81% at 6 months, and 16.7% at 1 year. The overall mortality was 35.58% and the re-intervention rate was 16.33%. IIA embolization is a feasible and safe procedure. The presence of EL is not superior to EVAR procedures that do not involve embolization.

DANCER: Study protocol of a prospective, non-randomized controlled trial for crossed limb versus standard limb configuration in endovascular abdominal aortic aneurysm repair.

Hostile anatomy, especially severely angulated neck and tortuous iliac arteries, has always been a conundrum in endovascular aneurysm repair (EVAR). Crossed limb (CL) graft, also called the "ballerina technique," has been utilized to address this problem by facilitating gate cannulation. In terms of short and long-term outcomes, correlated studies have made inconsistent conclusions and this issue remains controversial. Based on a previous cohort study conducted in our center, we aim to prospectively compare the safety and efficacy between CL and standard limb (SL) configuration in patients receiving EVAR. This is a prospective, single-center, non-randomized controlled trial. A total of 275 patients who meet the inclusion criteria will be enrolled and allocated with a 4:11 ratio of CL to SL, which is based on results of our previous study. All patients will receive same perioperative management and postoperative medications. All EVAR procedures will be performed under standard protocol, utilizing Endurant II or IIs Stent Graft. The configuration of the graft stent will be decided by surgeons and confirmed by final angiography. The primary outcome is 3-year freedom from major adverse limb-graft events (MALEs). Endpoints will be assessed at the following time points: 1, 6, 12, 24, and 36 months. To our best knowledge, this crosseD vs. stANdard Configuration in Endovascular Repair (DANCER) trial is the first non-randomized controlled trial to compare these two graft configurations in EVAR. The main aim is to compare the MALEs between two groups at 3 years postoperatively. This trial will hopefully provide high-level evidence for employing CL in EVAR. [www.chictr.org.cn], identifier [ChiCTR2100053055].

Intraoperative calf blood pressure measurements for the detection of early lower extremity ischemia following endovascular aneurysm repair.

Access vessel complications during endovascular aneurysm repair (EVAR) remain a concern and has been reported to occur in 3-10% of cases. The purpose of this study is to report our experience with intraoperative, non-invasive calf blood pressure (BP) measurements and ankle brachial indexes (ABIs) before and immediately following EVAR, in evaluating the perfusion of the lower extremities and detecting early lower extremity ischemia (LEI). We performed a retrospective review of all consecutive patients who underwent EVAR at our institution between the years 2019 and 2021. All patients had blood pressure cuffs placed on their calves prior to the procedure. Calf BP measurements and ABIs were obtained prior to and immediately after the surgery. Based on the BP measurements, patients were categorized into two groups. Group 1: patients with unchanged ABIs at the end of the procedure. Group 2: patients who experienced a decrease in ABIs at the end of the procedure (no BP obtained or decrease of ABI >0.3 from preoperative measurement). Patients in group 2 underwent exploration of the access vessel. Based on these, the positive and negative predictive values of the study were calculated. During the study period we performed 113 EVAR procedures for abdominal, thoracic, and thoracoabdominal aortic aneurysms, in which 226 femoral arteries were accessed. Mean age was 71years and 88% were males. In 219 (97%) of the limbs, there was no change in calf BP measurements and ABIs immediately after the procedure, when compared to the preoperative measurements, and none suffered a decrease in follow up ABIs. In 7 limbs (3%), there was a decrease in the calf BP (group 2), and all underwent exploration of the femoral artery. In 5 of these, a pathology was found within the artery. The positive predictive value of the intraoperative calf BP measurement was 71%. The negative predictive value of the study was 100%. Intraoperative calf BP and ABIs is a simple method to assess the lower limb perfusion and detect LEI following EVAR. The exam is particularly accurate in ruling out LEI as it has a very high negative predictive value. However, an abnormal measurement does not necessarily confirm LEI.

Negative Pressure Wound Therapy for the Prevention of Surgical Site Infections Using Fascia Closure After EVAR—A Randomized Trial

BackgroundSurgical site infections (SSI) in the groin after vascular surgery are common. The aim of the study was to evaluate the effect of negative pressure wound therapy (NPWT) on SSI incidence when applied on closed inguinal incisions after endovascular aneurysm repair (EVAR).MethodsA multicenter randomized controlled trial (RCT). Between November 2013 and December 2020, 377 incisions (336 bilateral and 41 unilateral) from elective EVAR procedures with the primary intent of fascia closure were randomized and included, receiving either NPWT or a standard dressing. In bilateral incisions, each incision randomly received the opposite dressing of the other side, thereby becoming each other’s control. The primary endpoint was SSI incidence at 90 days postoperatively, analyzed on an intention-to-treat basis. Uni and bilaterally operated incisions were analyzed separately, and their respective p-values combined using Fisher’s method for combining P-values. Study protocol (NCT01913132).ResultsThe SSI incidence at 90 days postoperatively in bilateral incisions was 1.8% (n = 3/168) in the NPWT and 4.8% (n = 8/168) in the standard dressing group, and in unilateral incisions 13.3% (n = 2/15) and 11.5% (n = 3/26), respectively (combined p = 0.49). In all SSIs, bacteria were isolated from incisional wound cultures. No additional SSIs were diagnosed between 90 days and 1 year follow-up.ConclusionsNo evidence of difference in SSI incidence was seen in these low-risk inguinal incisions when comparing NPWT with standard dressings after EVAR with the primary intent of fascia closure.Clinical Trials: NCT01913132.

Early Experience with Ovation Alto Stent-Graft

Alto is the latest generation of the Ovation stent-graft platform for endovascular aneurysm repair (EVAR). Its ultra-low profile and its proximal sealing zone close to the lowest renal artery (≥7mm) increase standard EVAR eligibility. We report early clinical and technical outcomes with the Alto stent-graft in our University Hospital Center after CE Mark approval in August2020. Seven patients (all male, mean age 76.1±6.2years) underwent EVAR with Ovation Alto stent-graft between June 2021 and February 2022. All the EVAR procedures were performed by a team of vascular surgeons experienced on EVAR with previous generation of Ovation platform. Follow-up consisted of duplex ultrasound examination at 1, 3, and 6months and of a 1-month control computed tomography angiography (CTA). Patients treated gave consent to participate in this case series and publication. A descriptive analysis of variables was performed. SPSS (version 25) and Excel were used for statistical analysis. Most of the patients had a fusiform abdominal aortic aneurysm (n=5; 71.4%). The median maximal transversal aortic diameter was 5.06cm (range, 3.98-6.99). Because of hostile aortic neck anatomy, on-label EVAR was considered feasible only with Ovation Alto stent-graft. Narrow iliac arteries (<6mm) were also present in 2 cases. All procedures were performed according to the instruction for the use of the device. Technical success was achieved in all cases. No type IA/IB/III endoleak occurred at completion angiography. No distal migration (>10mm) but 2 distal displacements (≥2mm) were observed at control CTA. During follow-up, duplex ultrasound and CTA showed no type I/III endoleak, no stent-graft migration (>10mm), and no proximal aortic neck variations (P=not statistically significant). Three patients (42.8%) are under strict surveillance because of low-flow type II endoleak not associated with sac variations. Our early experience shows promising technical and clinical success with Alto stent-graft. The proximal relocation of the proximal sealing rings and the ultra-low profile delivery system allow on-label EVAR in a wider range of aortic anatomies. Notwithstanding, further studies, meta-analysis, and prospective registries are mandatory to evaluate mid- and long-term efficacy and safety of this latest Ovation platform.

Simulation-Based Education of Endovascular Scrub Nurses Reduces Stress and Improves Team Performance

IntroductionEndovascular procedures have become commonplace in vascular surgery. This development calls for new training strategies for future specialists. Most simulation-based education (SBE) programs have a monodisciplinary focus on physicians, although successful surgery is a multidisciplinary team effort. Mental stress impairs the learning process and surgical performance and heart rate variability (HRV) can be measured as a proxy for both mental and physical stress. This study aims to assess how SBE of endovascular scrub nurses affects team performance and HRV during endovascular aneurysm repair (EVAR). Materials and methodsProspective interventional study in which EVAR-inexperienced scrub nurses followed a focused SBE EVAR program. During real-life EVAR procedures, HRV was continuously recorded with a wireless electrocardiogram patch and multidisciplinary team performance was assessed with the Imperial College Error CAPture (ICECAP) tool, before and after the SBE program, allowing each scrub nurse to serve as their own control. Eight scrub nurses with experience in lower limb endovascular procedures, but not EVAR, were invited to participate. ResultsSeven participants completed the study. In five of seven scrub nurses, HRV-derived stress levels during real-time EVAR procedures were lower after SBE compared to before SBE. Mean HRV increased from 24 msec to 35 msec (P < 0.001), indicating stress level reduction. Before SBE, the mean number of errors/hour was 7.3 (standard deviation ± 1.8) compared to 3.6 (standard deviation ± 2.7) after SBE. Most errors were categorized as technical (58 %) and communicative (23 %). ConclusionsSBE of scrub nurses may improve team performance and may lower mental stress during EVAR procedures. In this small study, we suggest using mental stress, as evaluated with HRV, and multidisciplinary team performance, as evaluated with ICECAP, to assess SBE effectiveness in real-case EVAR procedures. This SBE program and live ICECAP observations and electrocardiogram patches was well-accepted by scrub nurses and the entire team.

Is Evar Feasible in Challenging Aortic Neck Anatomies? A Technical Review and Ethical Discussion.

Background: Endovascular aneurysm repair (EVAR) has become an accepted alternative to open repair (OR) for the treatment of abdominal aortic aneurysm (AAA) despite “hostile” anatomies that may reduce its effectiveness. Guidelines suggest refraining from EVAR in such circumstances, but in clinical practice, up to 44% of EVAR procedures are performed using stent grafts outside their instruction for use (IFU), with acceptable outcomes. Starting from this “inconsistency” between clinical practice and guidelines, the aim of this contribution is to report the technical results of the use of EVAR in challenging anatomies as well as the ethical aspects to identify the criteria by which the “best interest” of the patient can be set. Materials and Methods: A literature review on currently available evidence on standard EVAR using commercially available endografts in patients with hostile aortic neck anatomies was conducted. Medline using the PubMed interface and The Cochrane Library databases were searched from 1 January 2000 to 6 May 2021, considering the following outcomes: technical success; need for additional procedures; conversion to OR; reintervention; migration; the presence of type I endoleaks; AAA-related mortality rate. Results: A total of 52 publications were selected by the investigators for a detailed review. All studies were either prospective or retrospective observational studies reporting the immediate, 30-day, and/or follow-up outcomes of standard EVAR procedures in patients with challenging neck anatomies. No randomized trials were identified. Fourteen different endo-grafts systems were used in the selected studies. A total of 45 studies reported a technical success rate ranging from 93 to 100%, and 42 the need for additional procedures (mean value of 9.04%). Results at 30 days: the incidence rate of type Ia endoleak was reported by 37 studies with a mean value of 2.65%; 31 studies reported a null migration rate and 32 a null conversion rate to OR; in 31 of the 35 studies that reported AAA-related mortality, the incidence was null. Mid-term follow-up: the incidence rate of type Ia endoleak was reported by 48 studies with a mean value of 6.65%; 30 studies reported a null migration rate, 33 a null conversion rate to OR, and 28 of the 45 studies reported that the AAA-related mortality incidence was null. Conclusions: Based on the present analysis, EVAR appears to be a safe and effective procedure—and therefore recommendable—even in the presence of hostile anatomies, in patients deemed unfit for OR. However, in order to identify and pursue the patient’s best interest, particular attention must be paid to the management of the patient’s informed consent process, which—in addition to being an essential ethical-legal requirement to legitimize the medical act—ensures that clinical data can be integrated with the patient’s personal preferences and background, beyond the therapeutic potential of the proposed procedures and what is generically stated in the guidelines.

Endovascular Abdominal Aortic Aneurysm Repair With Ovation Alto Stent Graft: Protocol for the ALTAIR (ALTo endogrAft Italian Registry) Study.

BackgroundSince 2010, the Ovation Abdominal Stent Graft System has offered an innovative sealing option for abdominal aortic aneurysm (AAA) by including a sealing ring filled with polymer 13 mm from the renal arteries. In August 2020, the redesigned Ovation Alto, with a sealing ring 6 mm closer to the top of the fabric, received CE Mark approval.ObjectiveThis registry study aims to evaluate intraoperative, perioperative, and postoperative results in patients treated by the Alto stent graft (Endologix Inc.) for elective AAA repair in a multicentric consecutive experience.MethodsAll consecutive eligible patients submitted to endovascular aneurysm repair (EVAR) by Alto Endovascular AAA implantation will be included in this analysis. Patients will be submitted to EVAR procedures based on their own preferences, anatomical features, and operators experience. An estimated number of 300 patients submitted to EVAR with Alto stent graft should be enrolled. It is estimated that the inclusion period will be 24 months. The follow-up period is set to be 5 years. Full data sets and cross-sectional images of contrast-enhanced computed tomography scan performed before EVAR, at the first postoperative month, at 24 or 36 months, and at 5-year follow-up interval will be reported in the central database for a centralized core laboratory review of morphological changes. The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with the Alto stent graft in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods. The following secondary endpoints will be also addressed: operative time; intraoperative radiation exposure; contrast medium usage; AAA sac shrinkage at 12-month and 5-year follow-up; any potential role of patients’ baseline characteristics, valuated on preoperative computed tomography angiographic study, and of device configuration (number of component) in the primary endpoint.ResultsThe study is currently in the recruitment phase and the final patient is expected to be treated by the end of 2023 and then followed up for 5 years. A total of 300 patients will be recruited. Analyses will focus on primary and secondary endpoints. Updated results will be shared at 1- and 3-5-year follow-ups.ConclusionsThe results from this registry study could validate the safety and effectiveness of the new design of the Ovation Alto Stent Graft. The technical modifications to the endograft could allow for accommodation of a more comprehensive range of anatomies on-label.Trial RegistrationClinicalTrials.gov NCT05234892; https://clinicaltrials.gov/ct2/show/NCT05234892International Registered Report Identifier (IRRID)PRR1-10.2196/36995

Safety of the endovascular aneurysm repair procedure: real-world evidence using interrupted-time series analysis.

In Taiwan, endovascular aneurysm repair for treating abdominal aortic aneurysms (AAA) was introduced in 2004 and became reimbursable in February 2010. We evaluated the real-world practice and safety of endovascular aneurysm repair in Taiwan. Patients who underwent repair operations for AAA (open or endovascular) from 2000 to 2016 were enrolled (n = 11485). Outcome statistics (during the index hospitalization: length of stay, rate of ischaemic bowel disease and 30-day mortality; after discharge: 30-day readmission rate, 2-year mortality, 2-year reintervention rate and 2-year paraplegia rate) were calculated for each half-year cohort. Propensity score-based stabilized weights were used to balance covariates among each half-year cohort. Interrupted time-series analysis was then performed. The elective and emergency ratio of AAA repair was 50:50 from 2000 to 2004 and became 60:40 from 2010 to 2016. The half-year rate of endovascular aneurysm repair was 0% in 2000 to 2004/06, 83.16% in 2010 and 98.1% in 2016. Interrupted time series analysis revealed that after endovascular aneurysm repair became reimbursable, both elective and emergency groups had a reduction in length of stay (-4.2 days, P < 0.0001; -1.5 days, P = 0.0928) and 30-day mortality (-5.22%, P = 0.0702; -7.76%, P = 0.0086) but a significant increase in the reintervention rate (5.05%, P = 0.0031; 4.36%, P = 0.0097). Endovascular aneurysm repair was predominantly used in treating AAAs after it was reimbursed in Taiwan. Endovascular aneurysm repair is efficacious regarding short-term outcomes but increased the 2-year reintervention rate in both groups.

Early Type II Endoleak Complication and Open Conversion Post Endovascular Aneurysm Repair of Ruptured Abdominal Aortic Aneurysm

Background: Endovascular Aneurysm Repair (EVAR) has been a long-stay surgical option to treat abdominal aortic aneurysms (AAA), both contained and ruptured. Endoleaks, defined as persistent flow in the aneurysm sac extrinsic to the endograft, is the most common complication. Type II endoleak (T2EL) results from collateral aortic branches (mainly lumbar arteries, inferior mesenteric artery) flowing retrogradely into the sac. It is often considered the Achilles' heel to EVAR due to the controversies in its timing of diagnosis and management. It is generally accepted that T2EL are slow growing, could expand the aneurysm sac, and carry a small but significant risk of aneurysm rupture. Case Presentation: This case reports an early post-EVAR complication due to T2EL. A 66-year-old man was brought to casualty hypotensive, minimally responsive with a rigid and tender abdomen. CT Angiography revealed a ruptured AAA contained within the retro peritoneum. The patient subsequently underwent an uncomplicated EVAR procedure. However, one-hour post procedure in ICU, he was found to be suddenly in haemorrhagic shock. Open conversion via exploratory laparotomy revealed 5L of blood within the peritoneum. Aneurysm sac was opened and four strong bleeding lumbar arteries were identified and oversewn to control the bleeding. It has hypothesised that vigorous T2EL from lumbar back-bleed, through the ruptured aneurysm sac led to ongoing bleeding into the contained retroperitoneum and subsequently secondary “rupture” into the peritoneal cavity. Conclusion: This case showed that T2EL are not all slow growing and innocuous. One should consider T2EL as a cause of a patient who is acutely deteriorating post-EVAR. Early CT-angiographic imaging post procedure may be indicated in certain groups.

Effect of Remote Ischemic Preconditioning on the Incidence of Contrast-Induced Nephropathy in Patients Undergoing Endovascular Aneurysm Repair (Remote Ischemic Preconditioning–Endovascular Aneurysm Repair Study)

Contrast-induced nephropathy (CIN) is a major inconvenience in the use of iodinated contrast media (ICM) and it is associated with a significant increase in morbidity and mortality and cost of hospitalization. Remote ischemic preconditioning (RIPC) is a noninvasive and cost-effective tissue protection technique that has showed to be beneficial in decreasing renal insult in patients receiving intravascular contrast. The primary outcome of this study is to evaluate the impact of RIPC on the incidence of CIN in patients undergoing endovascular aneurysm repair. Patients suffering from aortic aneurysm were recruited prior to the administration of ICM. Randomization was used to assign patients into the control/RIPC groups. Biochemical parameters determined renal function before and after surgery in immediate (24-72hr) and at 30days of follow-up. Of the 120 patients included in the study, 98,3% were male. Mean age was 73years (range: 56-87 years). Diabetes and chronic renal failure (considering estimated glomerular filtration [eGFR] <60) was present prior to administration of ICM in 29.16% and 38.33%, respectively. RIPC was applied in 50% (n=60) of the patients. A total of 24.17% developed CIN regardless of fluidotherapy, RIPC, and other protective strategies. RIPC did not influence outcomes in terms of incidence on CIN, serum creatinine, urea, eGFR, or microalbuminuria in immediate postoperative period. However, the group of RIPC patients showed a statistically significant benefit in renal function in terms of serum creatinine (1.46±0.3 vs. 1.03±0.5; P<0.001), urea (61.06±27.5mg/dL vs. 43.78±12.9mg/dL; P=0.003), and an increase in eGFR (56.37±23.4mL/min/1.73m2 vs. 72.85±17.7mL/min/1.73m2; P=0.004) at 30days of follow-up. RIPC seems to be a reasonable, effective, and low-cost technique to alleviate effects of ICM on the renal parenchyma in endovascular aneurysm repair procedures during short-term postoperative period.

A radiomics model for predicting the outcome of endovascular abdominal aortic aneurysm repair based on machine learning.

This study aimed to develop a radiomics model to predict the outcome of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), based on machine learning (ML) algorithms. We retrospectively reviewed 711 patients with infra-renal AAA who underwent elective EVAR procedures between January 2016 and December 2019 at our single center. The radiomics features of AAA were extracted using Pyradiomics. Pearson correlation analysis, analysis of variance (ANOVA), least absolute shrinkage, and selection operator (LASSO) regression were applied to determine the predictors for EVAR-related severe adverse events (SAEs). Eighty percent of patients were classified as the training set and the remaining 20 percent of patients were classified as the test set. The selected features were used to build a radiomics model in training set using different ML algorithms. The performance of each model was assessed using the area under the curve (AUC) from the receiver operating characteristic (ROC) curve in the test set. A total of 493 patients were enrolled in this study, the mean follow-up time was 32months. During the follow-up, 156 (31.6%) patients experienced EVAR-related SAEs. A total of 1223 radiomics features were extracted from each patient, of which 30 radiomics features were finally identified. The quantitative performance assessment and the ROC curves indicated that the logistics regression (LR) model had better predictive value than others, with accuracy, 0.86; AUC, 0.93; and F1 score, 0.91. The Rad-score waterfall plot showed that the overall amount of error was small both in the training set and in the test set. Calibration curve showed that the calibration degree of the training set and the test set were good (p > 0.05). Decision curve analysis (threshold 0.32) demonstrated that the model had good clinical applicability. Our radiomics model could be used as an efficient and adjunctive tool to predict the outcome after EVAR.

A patient-specific multi-modality abdominal aortic aneurysm imaging phantom

PurposeMultimodality imaging of the vascular system is a rapidly growing area of innovation and research, which is increasing with awareness of the dangers of ionizing radiation. Phantom models that are applicable across multiple imaging modalities facilitate testing and comparisons in pre-clinical studies of new devices. Additionally, phantom models are of benefit to surgical trainees for gaining experience with new techniques. We propose a temperature-stable, high-fidelity method for creating complex abdominal aortic aneurysm phantoms that are compatible with both radiation-based, and ultrasound-based imaging modalities, using low cost materials.MethodsVolumetric CT data of an abdominal aortic aneurysm were acquired. Regions of interest were segmented to form a model compatible with 3D printing. The novel phantom fabrication method comprised a hybrid approach of using 3D printing of water-soluble materials to create wall-less, patient-derived vascular structures embedded within tailored tissue-mimicking materials to create realistic surrounding tissues. A non-soluble 3-D printed spine was included to provide a radiological landmark.ResultsThe phantom was found to provide realistic appearances with intravascular ultrasound, computed tomography and transcutaneous ultrasound. Furthermore, the utility of this phantom as a training model was demonstrated during a simulated endovascular aneurysm repair procedure with image fusion.ConclusionWith the hybrid fabrication method demonstrated here, complex multimodality imaging patient-derived vascular phantoms can be successfully fabricated. These have potential roles in the benchtop development of emerging imaging technologies, refinement of novel minimally invasive surgical techniques and as clinical training tools.

Incidence and Fate of Refractory Type II Endoleak after EVAR: A Retrospective Experience of Two High-Volume Italian Centers.

Introduction: The aim of the present study is to report the outcome of patients presenting an isolated type II endoleak (TIIEL) requiring reintervention and to identify clinical and anatomical characteristics potentially implicated in refractory TIIEL occurrence and fate. Materials and Methods: A multicenter retrospective study on TIIEL requiring reintervention was conducted between January 2003 and December 2020. Demographic and clinical characteristics, procedural technical aspects, reinterventions, and outcomes were recorded. TIIEL determining sac expansion greater than 10 mm underwent a further endovascular procedure aiming to exclude aneurismal sac. Redo endovascular procedures were performed via endoleak nidus direct embolization and/or aortic side branches occlusion. TIIELs responsible for persisting aneurysmal sac perfusion 6 months after redo endovascular procedures were classified as “refractory” and submitted to open conversion. Results: A total of 102 TIIEL requiring reintervention were included in the final analysis. Eighty-eight (86.27%) patients were male, the mean age was 77.32 ± 8.08 years, and in 72.55% of cases the American Society of Anaesthesiologists (ASA) class was ≥3. The mean aortic diameter was 64.7 ± 14.02 mm, half of treated patients had a patent inferior mesenteric artery (IMA), and 44.11% ≥ 3 couples of patent lumbar arteries (LA). In 49 cases (48.03%) standard endovascular aneurysm repair (EVAR) procedure was completed without adjunctive maneuvers. All enrolled patients were initially submitted to a further endovascular procedure once TIIEL requiring reintervention was diagnosed; 57 patients underwent LAs or IMA embolization (55.87%), 42 transarterial aneurismal sac embolization (41.17%), and three (2.96%) laparoscopic ostial ligations of the inferior mesenteric artery. During a mean follow-up of 15.22 ± 7.57 months (7–48), a redo endovascular approach was able to ensure complete sac exclusion in 52 cases, while 50 patients presented a still evident refractory TIIEL and therefore a surgical conversion or semiconversion was conducted. At the univariate analysis refractory TIIEL patients were significantly different from those who did not develop the complication in terms of preoperative clinical, morphological characteristics, and initial EVAR procedures: coronary artery disease occurrence (p = 0.005, OR: 3.18, CI95%: 1.3–7.2); preoperative abdominal aortic aneurysm (AAA) sac diameter (p = 0.0055); IMA patency (p = 0.016, OR: 2.64, CI95%: 1.18–5.90); three or more patent LAs; isolated standard EVAR without adjunctive procedures (p > 0.0001; OR: 9.48, CI95%: 3.84–23.4). Conclusions: Our experience seems to demonstrate that it is reasonable to try to preoperatively identify those patients who will develop a refractory TIIEL after EVAR and those with a TIIEL requiring reintervention for whom a simple endovascular redo will not be enough, needing surgical conversion.

Long-term patency of surgical left subclavian artery revascularization

ObjectiveLittle is known regarding the long-term patency rates of surgical left subclavian artery (LSA) revascularization, especially when performed concomitant to thoracic endovascular aortic repair and without arterial occlusive disease. Our aim is to contribute to the existing evidence by reporting the patency rates at mid- and long-term follow-up after surgical LSA revascularization. MethodsThis observational, retrospective, single-center cohort study included 90 eligible patients who underwent a left common carotid artery to LSA bypass (72%) or transposition (28%) from December 31, 2017 to January 1, 2000. Data regarding demographics, medical history, intraoperative characteristics, and outcomes regarding bypass graft or transposition patency, severe stenosis, or occlusion were assessed at discharge, 3 months, 1 year, and maximum follow-up using consecutive follow-up computed tomography scans. ResultsIn our predominantly male (74%) cohort with a mean age of 66 years (standard deviation, ±12 years), LSA revascularization was mostly performed concomitant to or adjacent to thoracic endovascular aneurysm repair procedures (98%) with the primary indication for surgery being degenerative or saccular aneurysmatic aortic disease (50%), subacute or acute type B aortic dissection (17%), post-dissection aortic aneurysm (16%), type B intramural hematoma (6%), and other indications (11%). Ninety-seven percent of our left common carotid artery to LSA bypasses were performed using a central, supraclavicular approach, and the other 3% were performed using an infraclavicular approach to the LSA. Median diameter of the bypass was 6 mm (range, 6-12 mm). We found two occlusions at 7.7 and 12.9 months follow-up and four severe stenoses at 21.2, 35.4, 38.3, and 46.7 months follow-up, respectively. Estimated freedom from occlusion was 97% ± 2% and freedom from severe stenosis was 90% ± 4% at both midterm (5 years) and long-term (10 years) follow-up, with a median follow-up duration of 42.2 months for occlusion (25th-75th percentile, 15.4-67.4 months) and 41.9 months (25th-75th percentile, 15.4-67.4 months) for severe stenosis. ConclusionsOpen surgical LSA revascularization may be considered the gold standard to preserve antegrade LSA flow in the context of debranching for thoracic endovascular aneurysm repair or open surgical aortic arch repair, with excellent patency rates at mid-term and long-term follow-up.

C-reactive protein to albumin ratio provides important long-term prognostic information in patients undergoing endovascular abdominal aortic repair.

The prognostic value of C-reactive protein/albumin ratio (CAR) is of import in cardiovascular diseases. Our aim was to evaluate the impact of the CAR in patients with asymptomatic abdominal aortic aneurysm (AAA) undergoing endovascular aneurysm repair (EVAR). We retrospectively evaluated 127 consecutive patients who underwent technically successful elective EVAR procedure between December 2014 and September 2020. The optimal CAR cut-off value was determined by using receiver operating characteristic (ROC) curve analysis. Based on the cut-off value, we investigated the association of CAR with long-term all-cause mortality. 32 (25.1%) of the patients experienced all-cause mortality during a mean 32.7 ± 21.7 months' follow-up. In the group with mortality, CAR was significantly higher than in the survivor group (4.63 (2.60-11.88) versus 1.63 (0.72-3.24), p < 0.001). Kaplan-Meier curves showed a higher incidence of all-cause mortality in patients with high CAR compared to patients with low CAR (log-rank test, p < 0.001). Multivariable Cox regression analysis revealed that glucose ≥ 110mg/dL (HR: 2.740; 95% CI: 1.354-5.542; p = 0.005), creatinine ≥ 0.99mg/dL (HR: 2.957, 95% CI: 1.282-6.819, p = 0.011) and CAR > 2.05 (HR: 8.190, 95% CI: 1.899-35.320, p = 0.005) were the independent predictors of mortality. CAR was associated with a significant increase in postoperative long-term mortality in patients who underwent EVAR. Preoperatively calculated CAR can be used as an important prognostic factor.