Impact of introducing endovascular aneurysm repair on treatment strategy for repair of abdominal aortic aneurysm--National Hospital Organization network study in Japan

Long-Term Outcomes of Endovascular Aneurysm Repair in Patients Aged ≤70 Years

Objectives: The efficacy of endovascular aneurysm repair (EVAR) against abdominal aortic aneurysm (AAA) in younger patients remains unknown. Hence, the current study aimed to investigate whether the aneurysm-related mortality rate of EVAR is acceptable among patients aged ≤70 years. Methods: Among 644 patients, 148 underwent EVAR (EVAR group), and 496 received open surgical repair (OSR group). The cumulative incidence rates of aneurysm-related death, any intervention, and serious aneurysm-related events after AAA repair were evaluated using the cumulative incidence function in the presence of competing risks. Results: The EVAR group had higher prevalences of several comorbidities, and overall survival for the EVAR group was significantly inferior to that of the OSR group. The cumulative incidence rates of aneurysm-related death, any intervention, and serious aneurysm-related events at 5 years were 1.5%, 11.7%, and 6.4% in the EVAR group and 1.3%, 5.3%, and 5.9% in the OSR group, respectively. EVAR was not a significant prognostic factor of aneurysm-related mortality and serious aneurysm-related events. However, it was an independent poor prognostic factor of any intervention. Conclusion: EVAR was not a significant prognostic factor of aneurysm-related mortality and serious aneurysm-related events. Therefore, it demonstrated acceptable procedure-related long-term outcomes, at least in high-risk young patients.

Outcomes of abdominal aortic aneurysm repairs: Endovascular aneurysm vs open surgical repairs

BACKGROUND

Operative mortality after endovascular aneurysm repair (EVAR) has been reported as lower than open surgical repair (OSR) for abdominal aortic aneurysm (AAA) in randomized controlled trials. However, many cohort studies have demonstrated similar mortality rates for both procedures. We compared operative mortality between EVAR and OSR, at our institution.

METHODS

All AAA operations from 2012 to 2017 were reviewed, and baseline characteristics were collected. Outcomes included 30-day mortality, operative data, complications, length of hospital stay (LOS), costs, re-intervention, and survival rates were compared. A multivariable analysis with unbalanced characteristics was performed.

RESULTS

We had a total of 162 patients, 100 having OSR and 62 for EVAR. The EVAR group was older, with higher ASA classification. Thirty-day mortality rate did not significantly differ (0/100 for OSR and 2/62 (3%) for EVAR; p = 0.145), while the EVAR group had less blood loss, shorter operative times, and LOS, but higher re-intervention rates (adjusted hazard ratio 6.4 (95%CI: 1.4, 26.8)). Survival rates did not significantly differ between the groups. EVAR cost approximately 1-million yen more.

CONCLUSIONS

OSR had low 30-day mortality rate in selected low-risk patients whereas EVAR had less blood loss, shorter operative times, LOS and could be done in high-risk patients with low 30-day mortality but with higher re-intervention rate.

What Did Endovascular Aortic Repair Bring for the Treatment Strategy of Abdominal Aortic Aneurysm?

Objective: We examined the effects of the introduction of endovascular aortic repair (EVAR) on treatment for abdominal aortic aneurysms (AAAs).

Subjects: We compared patients in the following three periods: period I (January 2002–December 2006, 105 patients), period II (January 2007–December 2011, 242 patients, duration of 5 years after the introduction of EVAR), and period III (January 2012–December 2016, 237 patients, duration of 5 years after period II). We used the American Society of Anesthesiologists (ASA) classification for risk assessment.

Results: In the Open repair (OR) group, the incidences of ASA class 2 increased and classes 3 and 4 decreased significantly in periods II and III compared with period I. In all periods, there were no in-hospital deaths. Suprarenal aortic cross-clamping was required in 18 patients (19.1%) in period III and 5 patients (6.3) in period I, and the difference was significant (P<0.05). In the EVAR group, no differences in age, sex, or ASA classification class were observed between periods II and III. In period II, one patient died due to aneurysm rupture during surgery. Significant differences were observed when comparing both groups in periods II and III: patients in the EVAR group were older (P<0.01) and the OR group had a higher proportion of ASA class 2 patients and the EVAR group had a higher proportion of ASA class 3 or 4 patients (P<0.01). Among all AAA surgeries, rupture occurred in 25 patients (23.8%) in period I, 18 patients (7.4) in period II, and 16 patients (6.8) in period III. The number of ruptures was significantly lower in periods II and III than in period I (P<0.01).

Conclusions: The findings of this study suggest that EVAR should be indicated for high-risk patients and had the good outcome of AAA treatment. (This is a translation of Jpn J Vasc Surg 2018; 27: 27–32.)

Late Sac Behavior after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

BACKGROUND

Sac behavior after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) is considered as a surrogate for the risk of late rupture. The purpose of the study is to assess the sac behavior of AAAs after EVAR.

METHODS AND RESULTS

Late sac enlargement (LSE) (≥5 mm) and late sac shrinkage (LSS) (≥5 mm) were analyzed in 589 consecutive patients who were registered at 14 national centers in Japan. The proportions of patients who had LSE at 1, 3 and 5 years were 2.6% ± 0.7%, 10.0% ± 1.6% and 19.0% ± 2.9%. The proportions of patients who had LSS at 1, 3 and 5 years were 50.1% ± 0.7%, 59.2% ± 2.3% and 61.7% ± 2.7%. Multiple logistic regression analysis identified two variables as a risk factor for LSE; persistent endoleak (Odds ratio 9.56 (4.84-19.49), P <0.001) and low platelet count (Odds ratio 0.92 (0.86-0.99), P = 0.0224). The leading cause of endoleak in patients with LSE was type II.

CONCLUSIONS

The incidence of LSE is not negligible over 5 year period. Patients with persistent endoleak and/or low platelet count should carefully be observed for LSE.

CLINICAL TRIAL REGISTRATION

UMIN-CTR (UMIN000008345).

Characteristics and Risk Factors for Type 2 Endoleak in an East Asian Population From a Japanese Multicenter Database

BACKGROUND

Clinically distinct differences exist between East Asian and Caucasian subjects, but data for type 2 endoleak (T2EL) are limited in the East Asian population. The aim of this study was to analyze the characteristics of East Asian T2EL using a Japanese multicenter database.

METHODS AND RESULTS

Retrospective analysis of 832 endovascular aneurysm repairs performed from 2008 to 2014 were conducted. T2EL was observed in 234 cases (28.1%), and in 32 cases (3.8%) it led to sac expansion >5 mm caused by isolated T2EL (median follow-up, 35.6 months). On univariate and multivariate analysis, non-smoker status (odds ratio [OR], 2.216; P<0.001), Excluder stent graft (OR, 2.027; P<0.001), and T2EL at final angiogram (OR, 2.080; P<0.001) were risk factors for T2EL. On multivariate analysis for isolated T2EL with sac expansion, only non-smoker status remained (OR, 2.671; P<0.001). Other than T1EL, isolated T2EL was the most significant risk factor for sac expansion (OR, 18.486; P<0.001). Furthermore, out of 11 transarterial embolization procedures initiated, 4 led to rupture during follow-up.

CONCLUSIONS

East Asian T2EL had a strong relationship with non-smoker status. Also, T2EL was a significant risk factor for sac expansion, which sometimes led to rupture even after intervention. Along with the high prevalence of T2EL observed, East Asian T2EL may not always be benign.

Mortality of acute mesenteric ischemia remains unchanged despite significant increase in utilization of endovascular techniques

Introduction

In this study, we evaluated if increase in utilization of endovascular surgery has affected in-hospital mortality rates among patients with acute mesenteric ischemia.

Methods

The National Inpatient Sample (2003–2011) was queried for acute mesenteric ischemia using ICD-9 code for acute mesenteric ischemia (557.1). This cohort was divided into patients treated with open vascular surgery (open vascular group) and by endovascular therapies (endovascular group) based on the ICD-9CM procedure codes. Multivariable logistic regression was used to determine temporal trend for mortality while adjusting for confounding variables.

Results

There was 1.45-fold increase in utilization of endovascular techniques in this study. In-hospital mortality rate, total median charges and length of stay were significantly lower among the endovascular group than the open vascular group despite having significantly higher Elixhauser comorbidities index (3 ± 0.1 vs. 2.7 ± 0.1, p = .003). Over the course of the study period, there was no change in the overall mortality rate despite higher endovascular utilization. Factors associated with increased mortality included age, open surgical repair (Odds ratio: 1.45, 95% Confidence Interval: 1.10–1.91, p = .016) and bowel resection Odds ratio: 2.88, 95% Confidence Interval: 2.01–4.12).

Conclusion

The mortality rate for acute mesenteric ischemia remains unchanged throughout this contemporary study. Open surgical intervention, bowel resection and age were associated with increased mortality. Endovascular group patients had better survival despite higher morbidity indices.

Thoracic aortic injury in Japan--nationwide retrospective cohort study

BACKGROUND

The epidemiology of traumatic thoracic aortic injury has not been reported in many countries, so we investigated the current trends in Japan.

METHODS AND RESULTS

Patients with traumatic thoracic aortic injury from July 2007 to March 2013 were identified using a Japanese nationwide administrative database, the Diagnosis Procedure Combination inpatient database. The trends in crude in-hospital mortality and proportion of endovascular repair use among patients with repair were evaluated over time. A total of 617 incident cases of thoracic aortic injury were identified at 234 hospitals, and categorized into endovascular repair (n=126), open repair (n=76), and non-repair (n=415) groups. The in-hospital mortality rate for each of these groups was 5.6%, 15.8%, and 45.3%, respectively. The in-hospital survival rate was higher in the endovascular repair group than in the open repair group (log-rank χ(2)=4.9; P=0.03). Although the crude in-hospital mortality did not change significantly during the study period (Mantel-Haenszel trend test, P=0.10), the proportion of endovascular repair use among all repair cases increased significantly (P<0.001).

CONCLUSIONS

The results of the present nationwide study suggest that the endovascular approach to treatment of thoracic aortic injury in Japan gained in popularity from 2007 to 2012.