Open versus Endovascular Abdominal Aortic Aneurysm Repair in the Australian Private Sector Over Twenty Years

Trends in AAA Repair in Australia Over Twenty Years

Background

The advent of endovascular techniques has revolutionised the treatment of abdominal aortic aneurysms (AAA). Many countries have seen a transition from open AAA repair (OAR) to endovascular AAA repair (EVAR) over the past 25 years. The only study done in Australia that describes this change was done in the private sector. Majority of healthcare in Australia is delivered through the public, universal healthcare system. The aim of this study was to evaluate the trends in AAA repair in the Australian public sector over the past two decades.

Methods

The Australian Institute of Health and Welfare (AIHW) Procedures Data Cubes from the National Hospitals Data Collection was used to extract data pertaining to AAA repairs from 2000 to 2021. Population data from the Australian Bureau of Statistics was used to calculate incidence of each type of repair per 100,000 population.

Results

There were 65,529 AAA repairs performed in the Australian public sector from 2000 to 2021. EVARs accounted for 64.4% (42,205) and OARs accounted for 35.6% (23, 324) of them. EVAR surpassed OAR as the preferred method of AAA repair in 2006. This trend was observed in both males and females and across all age groups.

Conclusion

There was a consistent and steady transition from OAR to EVAR over the 21 year period with EVAR surpassing OAR as the preferred method of AAA repair relatively early in Australia compared to other countries. Further research that investigates medium- and long-term outcomes of newer stent grafts is needed to further ascertain the continued viability and effectiveness of this trend in AAA treatment.

Three-Year Safety and Efficacy of the INCRAFT Endograft for Treatment of Abdominal Aortic Aneurysms: Results of the INSIGHT Study

PURPOSE

Preliminary results of the INSIGHT study showed that the low-profile INCRAFT Abdominal Aortic Aneurysm (AAA) Stent-Graft System was safe and effective in the endovascular aneurysm repair (EVAR). This study aimed to assess the durability and the midterm effectiveness of EVAR using the INCRAFT System in the framework of a multicenter, prospective, open-label, post-approval study.

MATERIALS AND METHODS

Between 2015 and 2016, 150 subjects from 23 European centers treated with the INCRAFT System for an infrarenal AAA were included. Clinical and radiologic data were prospectively collected and analyzed using protocol-specified, monitored follow-up clinic visits at 1, 6, and 12 months post-implantation and annually after that. The clinical success at 3 years was determined. Freedom from overall and aneurysm-related mortality, type I endoleak, secondary interventions, and aneurysm sac enlargement through 3 years were evaluated. Kaplan-Meier estimates were used for late outcomes. An independent clinical events committee reviewed all events. The CT (computed tomography) scans through 1 year were reviewed by an independent core laboratory.

RESULTS

The primary clinical success rate at 3 years was 84.0% (126/150). There were no aneurysm-related deaths, endograft migration, or aneurysm-related ruptures through 3 years. Stent fracture was detected in 2 subjects (1.3%) without clinical sequelae. Over 3 years, freedom from overall mortality was 89.4%, freedom from secondary interventions was 80%, and freedom from aneurysm sac enlargement was 96.5%. The 3-year freedom from type IA and IB endoleaks was 93.3% and 98.6%, respectively.

CONCLUSIONS.

In a multicenter real-world study setting, the use of a low-profile INCRAFT device for AAA is associated with sustained clinical success and low rates of reinterventions through 3 years.

CLINICAL IMPACT

Low-profile endografts have broadened the spectrum of patients with anatomic suitability for endovascular repair of abdominal aortic aneurysms (AAA). However, questions remain regarding the durability of the repair. The INSIGHT study evaluated the use of the INCRAFT System in routine real-world clinical practice, including patients with complex anatomies. The treatment was safe and effective. The results showed sustained clinical success over 3 years, with no aneurysm-related deaths or ruptures, and a high rate of intervention-free survival at 3 years. Despite the low-profile design of the endograft, the midterm results demonstrate the durability of AAA repair using the INCRAFT System.ClinicalTrials.gov Identifier: NCT02477111.

Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era

Objective

Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes.

Materials and methods

A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward.

Results

A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666).

Conclusion

Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

Rural general surgeon confidence with managing vascular emergencies: A national survey

OBJECTIVE(S)

Life and limb threatening vascular emergencies often present to rural hospitals where only general surgery services are available. It is known that Australian rural general surgical centres encounter 10-20 emergency vascular surgery procedures annually. This study aimed to assess rural general surgeons' confidence managing emergent vascular procedures.

SETTING, PARTICIPANTS AND DESIGN

A survey was distributed to Australian rural general surgeons to determine their confidence (Yes/No) in performing emergent vascular procedures including limb revascularisation, revising arterio-venous (AV) fistulas, open repair of ruptured abdominal aortic aneurysm (AAA), superior mesenteric artery (SMA)/coeliac embolectomy, limb embolectomy, vascular access catheter insertion and limb amputation (digit, forefoot, below knee and above knee). Confidence level was compared with surgeon demographics and training. Variables were compared using univariate logistic regression.

RESULTS

Sixteen per cent (67/410) of all Australian rural general surgeons responded to the survey. Increased age, years since fellowship and training prior to 1995 (when separation of Australian vascular and general surgery occurred) were associated with greater confidence in limb revascularisation, revising AV fistulas, open repair of ruptured AAA, SMA/coeliac embolectomy, and limb embolectomy (p < 0.05). Surgeons who completed >6 months of vascular surgery training were more comfortable with SMA/coeliac embolectomy (49% vs. 17%, p = 0.01) and limb embolectomy (59% vs. 28%, p = 0.02). Confidence in performing limb amputation was similar across surgeon demographics and training (p > 0.05).

CONCLUSION

Recently graduated rural general surgeons do not feel confident in managing vascular emergencies. Additional vascular surgery training should be considered as part of general surgical training and rural general surgical fellowships.

The Impact of Iliac Artery Anatomy on Distal Landing Zone After EVAR During the 12-Month Follow-Up

BACKGROUND

Proximal sealing zone has been the main interest in endovascular abdominal aortic aneurysm repair (EVAR), although the distal landing zone remodeling may also affect EVAR durability. The aim of this study was to assess iliac anatomy and its potential impact on distal landing zone adverse events after EVAR during the 12-month follow-up.

METHODS

A prospective data collection of patients treated with standard bifurcated EVAR devices for abdominal aortic aneurysm was undertaken between 2017 and 2019. Patients that received extension to the external iliac artery were excluded. Follow-up included computed tomography angiography (CTA) at the 1st and 12th month postoperatively. The common iliac artery (CIA) diameter was assessed in three levels: origin (just below the aortic bifurcation), distally (just above the iliac bifurcation) and the middle of the distance between these two landmarks. Iliac angle, tortuosity indexes, relining and oversizing were also analyzed. Distal landing zone-related adverse events were any limb related re-intervention, endoleak type Ib, graft migration, limb stenosis, or occlusion.

RESULTS

In total, 268 iliac limbs (134 patients) were included. In all three levels, the mean iliac artery diameters increased at 12-month follow-up. At the origin of the CIA, the diameter increased from 18.7 ± 10.5 mm to 19.9 ± 9.4 mm (P = 0.04), at the middle portion of the CIA, the diameter changed significantly from 15.5 ± 5.1 mm to 17.4 ± 5.4 mm (P < 0.001) and at the distal CIA, from 14.6 ± 3.3 mm to 15.1 ± 3.9 mm (P = 0.03). The iliac angle remained stable (P = 0.14) while the CIA index decreased significantly from 1.17 ± 0.13 to 1.11 ± 0.09 (P < 0.001). The mean value of oversizing was 21.5 ± 14.5% and affected distal iliac diameter increase (P < 0.001). The composite outcome of distal landing zone adverse events was not associated to diameter changes at any level. In 57 cases, a distal iliac diameter ≥18 mm was recorded. The estimated oversizing was lower (16.3 ± 11.8%) compared to <18 mm arteries (22.5 ± 14.9%, P = 0.01). At 12-month follow-up, iliac diameters remained stable in the ≥18 mm group. Endoleak type Ib was more common in iliac arteries ≥18 mm [3 (5.3%) vs. 1 (0.5%) (P = 0.04)] at 12-months.

CONCLUSIONS

Post-EVAR iliac artery dilation does not seem to have an impact on distal landing zone adverse events during the 12-month follow-up. Aggressive oversizing may be related to iliac dilation. EVAR patients with iliac arteries ≥18 mm are at higher risk for ET Ib.