The outcomes and cost analysis of open repair and endovascular aneurysm repair for abdominal aortic aneurysms: a single-center experience in Japan

PURPOSE

Japan has adopted its own reimbursement system, which differs from other countries in terms of its diagnostic procedure combination (DPC) methods. However, there are few reports on the cost analysis of open repair and endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms in Japan. We aimed to evaluate the long-term outcomes and cost-effectiveness of these two procedures.

METHODS

This study included patients who underwent open repair (n = 224) and EVAR (n = 87) between January 2012 and December 2022. After propensity score matching, we compared the two groups.

RESULTS

The drug and blood products, procedures, and DPC costs were significantly higher in the open repair group (p < 0.001) than in the EVAR group. The surgical equipment and total costs were significantly higher in the EVAR group than in the open repair group (p < 0.001). There was no significant difference in the 5-year survival rate (88.5% in the open repair group vs. 72.0% in the EVAR group; p = 0.33) and freedom from re-intervention rate at 5 years (93.1% in the open repair group vs. 89.9% in the EVAR group; p = 0.15) between the two groups.

CONCLUSIONS

Open repair is more cost-effective than EVAR. The cost-effectiveness of EVAR may therefore depend on the cost of the endograft.

Long-Term Outcomes of Simple Endovascular Aneurysm Repair Based on the Initial Aortic Diameter

PURPOSE

We aimed to investigate the effects of initial abdominal aortic aneurysm (AAA) diameter on aneurysmal sac expansion/shrinkage, endoleaks, and reintervention postelective simple endovascular aneurysm repair (EVAR).

METHODS

Overall, 228 patients monitored for >1 year after EVAR were analyzed. Male and female participants with initial AAA diameters <55 mm and <50 mm, respectively, composed the small group (group S), while those with initial AAA diameters ≥55 mm (men) and ≥50 mm (women) composed the large group (group L). Aneurysmal sac expansion of 10 mm and/or reintervention during follow-up (composite event) and its related factors were evaluated.

RESULTS

The 5-year freedom from composite event rate was significantly higher in group S (92.4 ± 2.8%) than that in group L (79.1 ± 4.9%; P <0.01). Multivariate analysis revealed AAA diameters before EVAR in group S (hazard ratio, 0.38; 95% confidence interval, 0.18-0.81; P = 0.01) and type II endoleak (T2EL) at discharge (hazard ratio, 2.83; 95% confidence interval, 1.29-6.20; P <0.01) as factors associated with the composite event. The freedom from composite event rate decreased to 51 ± 13% at 5 years in group L with T2EL.

CONCLUSIONS

Group S had high freedom from composite event rate; in group L, the rate decreased to 51% at 5 years with T2EL at discharge.

One-year sac regression is associated with freedom from fatal adverse events after endovascular aneurysm repair

OBJECTIVE

Although the predictors of long-term prognosis after endovascular aneurysm repair (EVAR) have been investigated, several reports have suggested that early sac shrinkage (ESS) is associated with superior long-term prognosis. However, it was not clear whether ESS was associated with aneurysm-related mortality. The aim of this study was to define fatal adverse events and to examine their association with ESS.

METHODS

All consecutive patients who underwent EVAR for an abdominal aortic aneurysm at Nagoya University Hospital between June 2007 and August 2018 were identified. We defined ESS as an aneurysm diameter decrease of 10 mm or more at 1 year after EVAR, and we defined fatal adverse events as aneurysm-related death, aneurysm sac rupture, open conversion, secondary type Ia endoleak, or secondary type IIIa/b endoleak. Then, we evaluated the association between ESS and fatal adverse events and identified predictors of ESS.

RESULTS

During the study period, 553 patients were identified and included. Fatal adverse events occurred in 42 patients (7.6%), and the details of the fatal adverse events were as follows: 13 aneurysm-related deaths, 17 aneurysm sac ruptures, 14 open conversions, 13 type Ia endoleaks, and 6 type III endoleaks. ESS occurred in 146 patients (26.4%). Kaplan-Meier curves showed that the ESS group had a significantly lower incidence of fatal adverse events (P < .001). Multivariate analysis showed that there were significant differences in terms of 5 or more preoperatively patent lumbar arteries (odds ratio [OR], 0.67; P = .049; 95% confidence interval [CI], 0.45-1.00), chronic kidney disease (OR, 0.49; P < .01; 95% CI, 0.29-0.84), and Zenith endograft use (OR, 1.76; P < .01; 95% CI, 1.16-2.67). Furthermore, the percentage of cases that achieved an aneurysm diameter of less than 40 mm was significantly higher in the ESS group (76.0% vs 15.5%; P < .01). The use of Zenith endografts showed a significantly higher rate of aneurysm disappearance than the use of Endurant endografts (P < .01) and Excluder endografts (P < .01). In addition, it was found that ESS was more likely to occur with the use of Zenith endografts, even when propensity score matching was performed for the neck morphology.

CONCLUSIONS

ESS was associated with a lower rate of life-threatening adverse events after EVAR. The use of Zenith endografts was a predictor of ESS and was associated with increased rates of long-term sac shrinkage and aneurysm disappearance compared with the Endurant and Excluder endografts. Using the predictors of ESS identified in this study, we may be able to expand the indications for EVAR to patients with a longer life expectancy.

Impact of abdominal aortic aneurysm sac shrinkage following endovascular repair on long-term outcomes between favorable and hostile neck anatomy

OBJECTIVE

The aim of the present study was to analyze the influence of abdominal aortic aneurysm sac shrinkage on long-term outcomes after endovascular aneurysm repair (EVAR) between patients with favorable and hostile neck anatomy.

METHODS

This study retrospectively analyzed data from 268 patients with fusiform aneurysm and sac behavior who were evaluated for ≥1 year after EVAR. Hostile neck anatomy was defined as a proximal aneurysmal neck length of <10 mm or proximal neck angle of ≥60°. The primary endpoint was sac shrinkage, and the secondary endpoints included re-intervention and a composite of rupture, type 1a endoleak, and late open conversion.

RESULTS

There was no difference in sac shrinkage between patients with favorable and hostile neck anatomy (P = .47). Multivariate analysis revealed that occluded inferior mesenteric artery (P = .04), presence of posterior thrombus (P < .01), and no antiplatelet therapy (P = .01) were positive factors for sac shrinkage. The re-intervention free survival rate was better in patients with sac shrinkage compared with those without sac shrinkage regardless of proximal neck anatomy (P < .01). The event-free survival rate of the composite endpoint at 5 and 10 years were 97.5% and 83.5% in patients with favorable neck, and 86.8% and 81.0% in those with hostile neck (P = .02). In the subgroup with sac shrinkage, the event-free survival rates at 5 and 10 years were 98.7% and 98.7% in patients with favorable neck, and 92,7% and 82.4% in those with hostile neck (P = .02). In contrast, the event-free survival of patients without sac shrinkage did not differ between those with favorable and hostile neck (P = .08). Multivariate analysis showed that hostile neck anatomy (Hazard ratio [HR], 3.32; 95% confidence interval [CI], 1.26-8.80; P = .02) and no sac shrinkage (HR, 3.88; 95% CI, 1.25-12.0; P = .02) were significant risk factors for composite of rupture, type 1a endoleak, and late open conversion.

CONCLUSIONS

Proximal neck anatomy did not affect sac shrinkage after EVAR. Sac shrinkage is a good surrogate marker of better long-term outcomes after EVAR in patients with favorable neck anatomy. In contrast, critical events such as rupture or type 1a endoleak may occur even after sac shrinkage has been achieved in patients with hostile neck anatomy.

Endovascular Aneurysm Repair Compared With Open Repair Does Not Improve Survival in Octogenarians

BACKGROUND

Not every elderly person is frail, and whether it would be beneficial to perform endovascular aneurysm repair (EVAR) solely because a patient is older is unclear. This study aimed to compare the results of EVAR and open surgical repair (OSR) in elderly individuals.Methods and Results:From May 1998 to March 2021, 828 EVAR patients and 886 OSR patients with abdominal aortic aneurysm (AAA) were reviewed. Patients aged ≥80 years were included among them. After propensity score matching by age, sex, and American Society of Anesthesiologists (ASA) classification, the outcomes were compared between patients who underwent EVAR and OSR. The study cohort was composed of 351 EVAR patients and 90 OSR patients. The groups had similar comorbidities, except that EVAR patients were significantly older and had higher ASA classifications. After propensity score matching, 79 pairs of patients were selected. The 30-day mortality (0 vs. 1.2%) and aneurysm-related death (ARD) rates during follow up (2.3% vs. 2.3%, respectively) were similar between the groups. Kaplan-Meier curves revealed that estimated overall survival and freedom from ARD were also similar.

CONCLUSIONS

This study suggests that EVAR cannot improve survival outcomes compared with OSR if applied solely because a patient is aged ≥80 years. Not only age but also other risk factors and quality of life after surgery need to be further studied.

New Morphological Factor for Predicting Late Proximal Type I Endoleak after Endovascular Aneurysm Repair

BACKGROUND

Although we have witnessed several cases of late proximal type I endoleak (T1AEL) after endovascular aneurysm repair (EVAR), most patients did not have "hostile neck" preoperatively. We hypothesized that the distance between the lowest renal artery and the neck angulation point and neck length are the 2 most important factors for maintaining long-term proximal sealing. This study evaluated "neck hostility," which is the product of the distance to the angulation point and the neck length, as a preoperative morphological risk factor for the development of late T1AEL after EVAR.

METHODS

A retrospective review of a prospectively assembled database was performed for all patients who had undergone EVAR at a single institution from June 2007 to May 2017. Patient demographics and preoperative imaging data were collected, and Cox regression analysis was performed to identify the risk factors for late T1AEL.

RESULTS

Of the 655 patients who underwent EVAR during the study period, 115 were excluded due to complex EVAR (n = 14), primary indications for iliac aneurysms (n = 86), primary T1AEL (n = 3), or other reasons (n = 15). Of the remaining 537 patients, twelve patients (2.2%) developed late T1AEL a median of 3.2 (interquartile range [IQR]; 3.0, 5.4) years after EVAR. Receiver operating characteristic (ROC) curve analysis revealed a neck hostility cutoff value of 8. Cox regression analysis revealed that a neck hostility value ≤8 and conical neck anatomy were risk factors for the development of late T1AEL after EVAR. Well-known hostile neck factors such as short neck, severe angulated neck, and severe calcification/thrombus in the proximal neck were not significantly different.

CONCLUSIONS

The present study demonstrated a correlation between late T1AEL and the product of the angulation distance and the neck length. This factor may be useful for predicting poor late proximal outcomes after EVAR.

Preoperative sarcopenia and malnutrition are correlated with poor long-term survival after endovascular abdominal aortic aneurysm repair

PURPOSE

Sarcopenia and malnutrition are often used as surrogates for frailty, which is predictive of poor prognosis after surgery. We investigated the effects of sarcopenia and malnutrition on mortality after endovascular aneurysm repair (EVAR).

METHODS

The subjects of this study were patients who underwent EVAR at our hospital between June 2007 and December 2013, excluding those who underwent reintervention. The psoas muscle area at the L4 level was used as an indicator of sarcopenia. The Geriatric Nutritional Risk Index was used as an indicator of malnutrition.

RESULTS

There were 324 patients included in the study, with a mean age of 78.1 years and a median follow-up period of 56.7 months. Multivariate analysis revealed that sarcopenia (HR, 1.79; p = .042) and malnutrition (HR, 1.78; p = .043) were independent prognostic factors. Patients with both factors were classified as the high-risk group and others were classified as the low-risk group. The survival rate was significantly lower in the high-risk group than in the low-risk groups (p < .001). Even after propensity score matching, the high-risk group had a significantly lower survival rate (p < .001).

CONCLUSION

Both sarcopenia and malnutrition were associated with long-term mortality after EVAR. Patients with both indicators had a poor mid-term survival.

Analysis of prognostic factors for postoperative complications and reinterventions after open surgical repair and endovascular aneurysm repair in patients with abdominal aortic aneurysm

OBJECTIVE

A definitive treatment for patients with abdominal aortic aneurysm considering age and comorbidities has not been identified. In the present study, we retrospectively validated treatment outcomes in Japanese patients and proposed the treatment strategy of open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

We retrospectively analyzed data for patients undergoing EVAR or OSR between 2006 and 2017. Patients with ruptured abdominal aortic aneurysm were excluded. We examined post-operative complications, operative mortality, re-intervention and prognosis.

RESULTS

Throughout the study period, 405 patients underwent EVAR and 176 patients underwent OSR. The percentage of patients with post-operative complications was 35.8% in the OSR group, compared with 13.1% in the EVAR group (P < 0.01). The operative mortality rate was 0.49% in the EVAR group and 0.57% in the OSR group (P = 1.00). With a multivariate analysis, age, hemodialysis, modified Frailty Index (mFI), and OSR were risk factors for post-operative complications. The 5-year re-intervention free survival rate was 63.0 % with hostile neck EVAR compared with 83.1 % with favorable neck EVAR and 86.1 % with OSR group (P < 0.01). With a multivariate analysis, hemodialysis, mFI, and hostile neck EVAR were risk factors for re-intervention. The 5-year overall survival rate was 51.9 % with hostile neck EVAR compared with 73.2 % with favorable neck EVAR and 79.0 % with OSR group (P < 0.01). With a multivariate analysis, age, mFI, and hostile neck EVAR were poor prognostic factors.

CONCLUSION

Age, mFI, hemodialysis and hostile neck anatomy are useful predictors of post-operative complications, re-intervention and overall survival, and could be useful for informing treatment selection between OSR and EVAR.

Aneurysm Sac Thrombus Volume Predicts Aneurysm Expansion with Type II Endoleak After Endovascular Aneurysm Repair

BACKGROUND

Several studies have analyzed risk factors that may influence the incidence of type II endoleak with sac expansion after endovascular aneurysm repair (EVAR). However, the impact of intraluminal thrombus volume on the incidence of sac expansion with type II endoleak requires further analysis. This study examined the correlation between preoperative intraluminal thrombus and the incidence of type II endoleak and late sac expansion by measuring the thrombus volume.

METHODS

Between June 2007 and March 2014, 423 patients underwent EVAR at our institution. Two hundred and eighty patients with preoperative and postoperative computed tomography angiography (CTA) were included in this study. Data were collected prospectively and supplemented with a retrospective review of the medical records and radiologic images, and demographic and clinical characteristic profiles were collected. Logistic regression and Cox regression analyses were used to assess each variable's association with the incidences of persistent or new endoleak and sac expansion.

RESULTS

Of the 280 patients, 46.7% (131 patients) had persistent type II endoleak, and 19.6% (55 patients) had persistent type II endoleak with significant sac expansion (≥5 mm). The mean follow-up duration was 60 months (interquartile range, 24-72 months). Cox regression analysis showed that older age (P = 0.001), intraluminal thrombus volume ratio (thrombus volume [T vol]/aortic aneurysm volume [A vol]) (P = 0.042) and IMA diameter (P = 0.004) were significant predictors of the incidence of sac expansion with persistent or new type II endoleak. The receiver operating characteristic curve analysis revealed a cutoff of 51% T vol/A vol (area under the curve [AUC]: 0.59) and 2.9 mm (area under the curve [AUC]: 0.60). The rate of freedom from sac expansion (≥5 mm) during followup was significantly higher in patients with ≥51% T vol/A vol than in those with a lower T vol/A vol (P = 0.010).

CONCLUSIONS

Preoperative sac thrombus volume, IMA diameter, and older age predict the incidence of aneurysm expansion with type II endoleak after EVAR.

Outcomes of Endovascular Repair for Abdominal Aortic Aneurysms: A Nationwide Survey in Japan

OBJECTIVE

To analyze data on patients treated with a bifurcated stent graft for abdominal aortic aneurysm (AAA).

BACKGROUND

The Japan Committee for Stentgraft Management (JACSM) was established in 2007 to manage the safety of endovascular aortic aneurysm repair (EVAR) in Japan. The JACSM registry includes detailed anatomical and clinical data of all patients who undergo stent graft insertion in Japan.

METHODS

Among 51,380 patients treated with bifurcated stent graft for AAA, we identified 38,008 eligible patients (excluding those with rupture or insufficient data). The analyzed factors included age, sex, comorbidities, AAA pathology and etiology, aneurysm and neck diameters, 7 anti-instructions for use (IFU) factors, and endoleaks at hospital discharge. The endpoints were death, adverse events, sac dilatation (≥5 mm), and reintervention.

RESULTS

The rates of intraoperative and in-hospital mortality were 0.08% and 1.07%, respectively. Infectious aneurysm and pseudo-aneurysm were associated with overall survival and reintervention. Older age, large aneurysm diameter, and all types of persistent endoleaks were strong predictors of adverse events, sac dilatation, and reintervention. Comorbid cerebrovascular disease, renal dysfunction, and respiratory disorders were also risk factors. In total, 47.6% of patients violated the IFU; among the anti-IFU factors assessed, poor access and severe neck calcification were strong risk factors for mortality, reintervention, and adverse events. The sac dilatation rate at 5 years was 23.3%.

CONCLUSIONS

Although the analysis included EVAR with poor anatomy, the perioperative mortality rate was acceptable compared with that in previous large population studies.

Long-term Comparison of Endovascular and Open Repair of Abdominal Aortic Aneurysms: Retrospective Analysis of Matched Cohorts with Propensity Score

BACKGROUND

Although recent guidelines recommend endovascular aneurysm repair (EVAR) for robust younger patients, we have been limiting our indication to older patients or those who are physically frail. This study compares long-term outcomes of our series of abdominal aortic aneurysms (AAAs) treated with endovascular repair (ER) and open surgery (OS), using propensity score matching.

METHODS

Between June 2007 and October 2014, 819 patients with infrarenal AAA underwent elective repair at our institution. Among them, 737 patients (386 ERs and 351 OSs) with over 1-year follow-up or any events (reintervention or mortality) were enrolled. Covariates for matching included age, sex, hypertension, coronary arterial disease, obstructive pulmonary disease, diabetes, stroke, malignancy, hemodialysis, ejection fraction, serum creatinine, and respiratory function.

RESULTS

After propensity score matching, 157 pairs were selected. In the original cohort, overall survival at 5 years was 84.1% in ER and 89.3% in OS; the difference was significant (P = 0.019). The freedom-from-reintervention rates at 5 years were also significantly different, 81.8% in ER and 92.8% in OS (P = 0.007). In the matched cohort, age and comorbidities were similar both in ER and OS. The overall survival at 5 years was 85.4% and 90.1% in ER and OS, respectively; the difference was not significant (P = 0.242). The freedom-from-reintervention rates at 5 years were 81.1% in ER and 89.1% in OS; these were also not significantly different (P = 0.178).

CONCLUSIONS

Risk-adjusted comparisons revealed that long-term outcomes of ER and OS were comparable among our relatively frail patients in their age 70s. Our results failed to show the long-term advantage of EVAR in rather high-risk patients and provided no supportive evidence for our selection criteria.