Elective endovascular vs. open repair for abdominal aortic aneurysm in octogenarians

Abstract

Purpose

The purpose of this study was to investigate the operative mortality and short-term and midterm outcomes of treatment of abdominal aortic aneurysm in Japanese patients over 80 years of age.

Methods

Between January 2007 and December 2011, 207 patients underwent elective repair of infrarenal abdominal aortic aneurysms. Comorbidities, operative morbidity and mortality, midterm outcomes were analyzed retrospectively.

Results

The average age (endovascular aneurysm repair, 84.4 ± 0.3; open, 82.8 ± 0.3, P < 0.01) and the percentage of hostile abdomen (endovascular aneurysm repair, 22.2%; open repair, 11.1%, P < 0.05) were higher in the endovascular aneurysm repair group. Percentage of outside IFU was higher in open repair (endovascular aneurysm repair, 38.5%; open repair, 63.3%, P < 0.01). The cardiac complication (endovascular aneurysm repair, 0%; open repair, 5.6%, P < 0.01) and length of postoperative hospital stay (endovascular aneurysm repair, 10.3 ± 0.8 days; open, 18.6 ± 1.6 days, P < 0.05) were significantly lower in the endovascular aneurysm repair group. There were no differences in operative mortality (endovascular aneurysm repair, 0%; open, 1.1%, P = 0.43) and the aneurysm-related death was not observed. The rate of secondary interventions (EVAR, 5.1%; open repair, 0%, P < 0.01) and midterm mortality rate were much higher in the endovascular aneurysm repair group.

Conclusions

Endovascular aneurysm repair is less invasive than open repair and useful for treating abdominal aortic aneurysm in octogenarians; however, open repair can be acceptable treatment in the inappropriate case treated by endovascular aneurysm repair.

Keywords

Abdominal aortic aneurysm endovascular aneurysm repair open aneurysm repair octogenarians

Introduction

Treatment of abdominal aortic aneurysms (AAAs) using endovascular aneurysm repair (EVAR) with commercial stent-grafts began in 2006 in Japan. Since then, a remarkable paradigm shift in the treatment of AAA has occurred. In particular, high-risk and elderly patients, who in the past were followed up are often treated with EVAR. EVAR has the benefits of reduced blood loss, shorter hospital stays, and decreased operative mortality compared to open aneurysm repair.^1–3

Japan is well on its way to becoming an aging society. Therefore, the number of elderly and high-risk patients with AAA is expected to increase. Several overseas reports have indicated decreased operative morbidity and mortality during the perioperative period in octogenarians treated with EVAR.^4–6 The purpose of this study was to investigate the short-term and midterm outcomes of EVAR and open repair of AAA in Japanese patients over 80 years of age.

Methods

Between January 2007 and December 2011, 656 patients underwent elective repair of infrarenal AAAs at the Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University and Department of Vascular Surgery of Kokura Memorial Hospital. Of these patients, 207 over 80 years of age were the focus of this analysis. Approval for this project was obtained from the institutional review board for research on human subjects. A retrospective analysis was performed, and patient’s data were obtained from medical, operative and radiology records. In this study, previous abdominal surgery was defined as hostile abdomen, and chronic obstructive pulmonary disease (COPD) was defined as the state of stage III of the global initiative for chronic obstructive lung disease corresponding to FEV1.0% < 50%. Patients with ruptured aneurysms and aneurysms involving the renal arteries were excluded from this analysis. The main outcome measures were operative death (defined as death occurring <30 days after surgery or during the same hospital stay), amount of blood loss, length of hospital stay, and short-term and midterm mortality.

With regard to our strategy of treatment of AAA, EVAR was the first choice if the case was inside of instruction for use (IFU). Even if the case was inside of IFU, open repair was performed if the patient desires. The cases outside IFU with the angulated neck (proximal neck > 60°) and neck length over 10 mm were treated by EVAR. The patients with short neck (neck length < 10 mm) were treated by open repair. Preoperative cardiac evaluation was performed by the cardiologist. If necessary, adenosine thallium scanning, coronary computed tomography (CT), dobutamine echocardiography, or coronary angiography was performed as preoperative cardiac assessment. The patients with cardiopulmonary disease were consulted to anesthesiologist, and then the patients diagnosed as intolerable for general anesthesia and open repair were observed in outpatient department. EVAR was performed as follows: under general anesthesia, oblique incisions were made on bilateral groins and bilateral common femoral arteries were exposed. After intravenous administration of heparin, stent-graft implantation was performed. Open surgery was performed as follows: under general anesthesia, laparotomy was performed with an upper to lower midline skin incision. The aortic neck under the renal arteries and bilateral iliac arteries were exposed. After intravenous administration of heparin and clamped, the aneurysm sac was incised. Aortic neck and iliac arteries were transected and anastomosis was performed by continuous suture.

Patients followed-up in EVAR were performed with computed tomographic angiography (CTA) before discharge, 3, 6, and 12 months postoperatively and annually thereafter. Indication for intervention was type 1, type 3 endoleak, or type 2 endoleak with the aneurysm sac growth of 5 mm or more. The patients treated by open repair were followed up by CTA before discharge, and CTA was performed annually thereafter.

The characteristics and distribution of risk factors in the patient groups were analyzed using the χ² tests for categorical variables and Student’s t-test for continuous variables. The Kaplan–Meier life table method was employed, and comparisons were made using Wilcoxon and log-rank analyses. Statistical significance was set at a P value of < 0.05. All statistical analyses were conducted using the JMP® 9 software program (SAS Institute Inc., Cary, NC, USA).

Results

One hundred and seventeen octogenarians underwent EVAR, while 90 underwent open repair. Technical success rates were 91.6% in EVAR group. Technical failure was not observed in open repair. Only one case in EVAR was converted to open repair due to inability to pass the iliac vessels with the stent-graft. Figure 1 demonstrates the proportions of EVAR and open repair procedures performed between 2007 and 2011 in the octogenarians. The rate of EVAR gradually increased from 26.9% then plateaued at approximately 60–70%. The percentage of outside of IFU was 43.6% overall. At first year, 14.3% was outside of IFU; however, half of the case was outside the IFU at last year (Figure 2). There was no significant difference between the first and last year of the experience (P = 0.21). The mean follow up was 26.7 ± 1.5 months in the EVAR group and 23.7 ± 2.5 months in the open repair group. The proportion of devices in EVAR was as follows: excluder was 53%, Zenith was 38.5%, and Powerlink was 8.5%.

Figure 1.

The proportion of EVAR vs. open repair performed between the years 2007 and 2011. The proportion of EVAR is gradually increased from 26.9% and comes to a plateau about 60–70%.

Figure 2.

The proportion of instruction for use in EVAR.

Characteristics of the two groups are shown in Table 1. The average age was higher in the EVAR group (EVAR, 84.4 ± 0.3; open, 82.8 ± 0.3, P < 0.01). The percentage of history of abdominal operation was higher in EVAR treated group (EVAR, 22.2%; open repair, 11.1%, P < 0.05). Percentage of outside IFU was higher in open repair (EVAR, 38.5%; open repair, 63.3%, P < 0.01). With regard to pathology, almost cases of AAA were degenerative. Three cases of open repair group were caused by inflammatory, dissection, and pseudo-aneurysm, respectively. Only one case of EVAR group was pseudo aneurysm after open repair. There were no differences in pathology of aneurysm. The operative time (EVAR, 161.8 ± 6.6 min; open, 240.1 ± 10.9 min, P < 0.05), amount of blood loss (EVAR, 355.2 ± 45.2 mL; open, 1245.2 ± 1126.8 mL, P < 0.05), and length of postoperative hospital stay (EVAR, 10.3 ± 0.8 days; open, 18.6 ± 1.6 days, P < 0.05) were significantly lower in the EVAR group (Table 2). The operative mortality was similar between the EVAR and open repair groups (EVAR, 0%; open, 1.1%, P = 0.43). Figure 3 demonstrates Kaplan–Meier plots showing the midterm survival rates of the patients treated with EVAR and open repair. The patients treated by open repair had significantly better midterm survival than those treated by EVAR. Aneurysm-related death was not observed in this study, and the causes of death in short-term and midterm period were other reasons such as cancer, cardiovascular and cerebrovascular events.

Table 1.

Demographic data and preoperative risk factors.

	EVAR	Open
Variable	(n=117)	(n=90)	P
Age, mean ± SD (years; range)	84.4±0.3 (80–97)	82.8±0.3 (80–91)	<0.01
Males, no. (%)	80 (68.4)	58 (64.4)	0.56
aneurysm size (mm; range)	53.7±0.9 (35–90)	54.2±1.1 (33–79)	0.63
Hypertention, no. (%)	91 (77.0)	76 (84.4)	0.29
DM, no. (%)	12 (18.8)	17 (18.9)	0.99
CAD, no. (%)	38 (32.5)	32 (35.6)	0.66
COPD, no. (%)	18 (15.4)	6 (6.7)	0.08
renal dysfunction (Cr < 1.5)	17 (14.5)	9 (10.0)	0.40
Stroke, no. (%)	16 (13.7)	6 (6.7)	0.12
Hostile abdomen	26(22.2)	10(11.1)	0.04
Outside of IFU	45 (38.5)	57 (63.3)	<0.01
Medication
Aspirin	42 (35.9)	41 (45.6)	0.20
Clopidogrel	2 (1.7)	5 (5.6)	0.24
Sarpogrelate	4 (3.4)	3 (3.3)	1.00
Cilostazole	4 (3.4)	3 (3.3)	1.00
Ticlopidine	0 (0)	8 (8.9)	<0.01
Statin	27 (23.1)	31 (34.4)	0.08

DM: diabetes mellitus; CAD: coronary artery disease; COPD: chronic obstructive pulmonary disease; EVAR: endovascular aneurysm repair; IFU: instruction for use.

Table 2.

Patients’ results.

	EVAR	Open
Variable	(n=117)	(n=90)	P
Length of hospital stay	21.5 ± 6.8	23.0 ± 1.7	0.57
Mean ± SD, days	21.5 ± 6.8	23.0 ± 1.7	0.57
length of postoperative hospital stay	10.3 ± 0.8	18.6 ± 1.6	<0.05
Mean ± SD, days	10.3 ± 0.8	18.6 ± 1.6	<0.05
Operative time, mean ± SD, min	161.8 ± 6.6	240.1 ± 10.9	<0.05
Blood loss, mean ± SD, mL	355.2 ± 45.2	1245.2 ± 126.8	<0.05
Operative mortality, no. (%)	0 (0)	1 (1.1)	0.43

EVAR: endovascular aneurysm repair.

Figure 3.

Superior midterm survival for open repair group compared to EVAR group.

The postoperative complications are presented in Table 3. The number of patients with at least one complication was significantly lower in the EVAR group (EVAR, 4.3%; open, 14.4%, P < 0.01). In particular, the rate of cardiac complications was significantly higher in the open repair groups (EVAR, 0%; open, 5.6%, P < 0.01).

Table 3.

Major complications at 30 days.

	EVAR	Open
Variable	n=117	n=90	P
Cardiac	0 (0%)	5 (5.6%)	0.01
Pulmonary	2 (1.7%)	4 (4.4%)	0.41
Cerebrovascular	0 (0%)	1 (1.1%)	0.43
Renal insufficiency	1 (0.8%)	2 (2.2%)	0.58
Bowel ischemia	1 (0.8%)	4 (4.4%)	0.43
Wound	1 (0.8%)	0 (0%)	0.58
Total patients (with at least one complication)	5 (4.3%)	13 (14.4%)	0.01

EVAR: endovascular aneurysm repair.

The EVAR group required six (5.1%) secondary interventions (Table 4). Two type 1A endoleaks were repaired with proximal aortic cuff placement, one of which was diagnosed as a ruptured aneurysm two years after implantation. Another case of type 1A endoleak occurred one month after EVAR. Two type 1B endoleaks were repaired with iliac leg extension at two and three years after first operation. In addition, femoro-femoral bypass was performed in two patients due to occlusions of iliac legs at two and eight months after operation. Of the six cases, only one case was outside IFU involving a type 1A endoleak. There were no secondary interventions in the open repair group.

Table 4.

Reintervention in long-term period.

	EVAR	Open
Variable	n=117	n=90	P
Replacement aortic cuff due to type 1A endoleak	2 (1.7%)	–
Replacement iliac extension due to type 1B endoleak	2 (1.7%)	–
FF bypass due to occlusion of iliac legs	1 (0.8%)	–
Total	6 (5.1%)	0 (0%)	0.01

EVAR: endovascular aneurysm repair; FF bypass: femoro-femoral bypass.

Discussion

EVAR is less invasive than open aneurysm repair. A recent study of EVAR vs. open repair in a Medicare population reported a lower short-term death rate and reduced complications in patients treated with EVAR.⁷ In the long-term, secondary intervention related to AAA was more common in the EVAR-treated group.⁷ The introduction of EVAR has changed the decision-making process regarding treatment strategies for elderly and high-risk patients with AAA, who were previously considered unfit for open repair. There are several overseas reports comparing the use of EVAR and open repair in octogenarians; however, clinical outcomes in Japan have not been reported.^1–3 Therefore, we investigated the short-term and midterm outcomes of EVAR and open repair of AAA among patients over 80 years of age treated at our institutions.

In this retrospective study, there were midterm survival disadvantages for EVAR group. Probably, it was because that the average age was higher in the EVAR compared to open repair group. In long-term survival, a series of 150 patients over 80 years of age who underwent elective repair of infrarenal AAA showed no differences in long-term survival between the two studied groups.⁸ Another report of octogenarians demonstrated no advantages for EVAR compared to open repair regarding long-term survival.⁹ Long-term data from the EVAR1, DREAM, and OVER trials showed equivalent long-term survival rates in all age groups.^9–11 There have been no randomized studies in octogenarians; however, benefits in long-term mortality following EVAR treatment in octogenarians may not be observed.

In this study, the operative mortality was similar in the EVAR and open repair groups. Paolini et al.⁸ reported no differences in operative mortality in a series of 150 patients over 80 years of age who underwent elective repair of infrarenal AAA. However, five studies showed higher immediate postoperative mortality rates following open aneurysm repair compared to EVAR.^4–7,12 These studies reported operative mortality rates ranging 1.8–3.7% in patients undergoing EVAR and 5.3–9.9% in patients undergoing open aneurysm repair. The operative mortality in Japan is different from that observed in other countries; therefore, the data in this study are important as outcomes of Japanese patients. Tochii et al.¹³ reported that an age over 80 years is a risk factor with respect to surgical treatment of AAA; however, age alone is not a risk for operative death, considering the lack of no benefits of short- and long-term survival.

There were no differences in operative mortality in this study, although the rate of major complications in the perioperative period was lower in the EVAR group, resulting in shorter postoperative hospital stays. The findings of reduced major complications in the EVAR group are similar to the result of another report.^4,14 Due to the reduced invasiveness of EVAR, EVAR is preferred for octogenarians requiring AAA treatment with expectations for reduced of morbidity.

Table 5 summarizes the current literatures of treatment for AAA in octogenarians.^{4–8,12,15–25} In this study, the incidence of CAD was 33.8%. The percentage of CAD varies by reports or countries, 21–33.3% in Japan^20,23 and 34–69% in US,^{5–8,16,24,25} which may be caused by the difference of the lifestyle. However, as the rate of aging and westernization of the life style has accelerated in Japan, the incidence of acute coronary syndrome has been increased over 30 years.²⁶ In the future, the percentage of CAD in Japanese population may close with that of US. Treatment decision was individually based considering comorbidities and the patients’ will. Preoperative cardiac evaluation was performed by the cardiologist. If necessary, adenosine thallium scanning, coronary CT, dobutamine echocardiography, or coronary angiography was performed as preoperative cardiac assessment. Such careful preoperative examination may lead to the good operative mortality in this study.

Table 5.

Summary of current literatures of outcome after elective treatment of abdominal aortic aneurysm in octogenarians.

Study	n	Treatment type	Comorbidity of CAD (%)	Operative mortality (%)	Complication
Study	n	Treatment type	Comorbidity of CAD (%)	Operative mortality (%)	Cardiac (%)	Pulmonary (%)	Renal failure (%)
O'Donnell et al.¹⁵	44	Open repair	–	2.0	38.6	25	–
Treiman et al.¹⁶	35	Open repair	34.0	8.6	34.2	14.3	14.3
Harris et al.¹⁷	34	Open repair	–	2.9	–	–	–
Robson et al.¹⁸	14	Open repair	–	4.6	–	–	–
Dean et al.¹⁹	18	Open repair	–	5.6	–	–	–
Sugawara et al.²⁰	15	Open repair	33.3	0.0	–	–	–
Sicard et al.⁶	38	Open repair	45.0	5.3	18.4	2.6	2.6
Sicard et al.⁶	52	EVAR	69.0	1.9	3.8	0	0
Patel et al.²¹	30	Open repair	–	3.3	–	–	–
Patel et al.²¹	16	EVAR	–	0.0	–	–	–
Leon et al.¹²	1604	Open repair	–	9.9	–	–	–
Leon et al.¹²	351	EVAR	–	3.7	–	–	–
de Donato et al.⁴	12	Open repair	48.1	8.3	8.3	16.6	8.3
de Donato et al.⁴	32	EVAR	48.1	3.1	3.1	0	0
Ballotta et al.²²	111	Open repair	42.3	1.8	0	1.8	0
Ishibashi et al.²³	108	Open repair	21.0	7.0	–	–	–
Schermerhorn et al.⁷	4566	Open repair	–	8.4	–	–	–
Schermerhorn et al.⁷	4588	EVAR	–	1.9	–	–	–
Paolini et al.⁸	69	Open repair	46.4	8.5	–	–	–
Paolini et al.⁸	81	EVAR	51.9	5.0	–	–	–
Fonseca et al.²⁴	117	EVAR	53.0	1.0	1.7	5.1	6.0
Geisbüsch et al.²⁵	279	EVAR	38.0	2.8	3.2	1.4	2.8
Raval and Eskandari⁵	391	Open repair	36.3	6.1	1.5	11.3	2.3
Raval and Eskandari⁵	1634	EVAR	38.6	1.8	0.2	1.6	1.0
Present series	90	Open repair	35.6	1.1	5.6	4.4	2.2
Present series	117	EVAR	32.5	0.0	0.00	1.7	0.8

EVAR: endovascular aneurysm repair.

As compared to US series, length of hospital stay was extended in this study. The differences of length of hospital stay would be caused by the differences of insurance system. Universal health care system has been adopted in Japan; less expensive hospitalization fee compared to US may lead to the long hospital stay. Considering the postoperative conditions, the length of hospital stay could be reduced.

EVAR is less invasive; however, the rate of secondary intervention was significantly higher in the EVAR group than in the open repair group. The EVAR group required six (5.1%) secondary interventions. In one case, aneurysm rupture occurred due to a type 1A endoleak. A proximal aortic cuff was successfully replaced during emergency surgery. Rupture due to type 1A endoleak would be caused by enlargement of proximal neck regardless of the case within IFU. Another case of type 1A endoleak occurred due to severe angulation of proximal neck. Two case of type 1B endoleak were caused by expansion of common iliac arteries. Type 1A with rupture and two type 1B were treated by Zenith, another case of type 1A endoleak due to angulation was treated by excluder.

Of the six cases, only one case was outside IFU involving a type 1A endoleak. Abbruzzes et al.²⁷ demonstrated that graft placement outside of IFU is associated with similar rates of five-year freedom from aneurysm-related death, migration, and reintervention; however, in that study, there was a significantly lower rate of freedom from graft-related adverse events (74% outside IFU vs. 86% within IFU). EVAR has the benefit of reduced invasiveness due to a decreased rate of major complications and shorter hospital stays; however, indications for aneurysm treatment should not be determined based only on age, considering the higher frequency of secondary intervention in the EVAR group compared to that observed in the open repair group.

In treatment choice of AAA, we think EVAR is the first choice considering of less invasiveness of EVAR and no differences of aneurysm-related death in EVAR and open repair. However, EVAR needs more secondary intervention; therefore, scheduled follow up is necessary. And then, considering operative mortality in this study, open repair could be an acceptable treatment option for the unfit case treated by EVAR in octogenarians, whose general status was tolerable for general anesthesia and open surgery.

The study limitations of this study included the retrospective study design and nonrandomization of patients; therefore, there may be a treatment selection bias. Moreover, the decision to treat AAA patients with EVAR if anatomically fit, limiting open aneurysm repair to anatomically complex cases, represents another selection bias.

Conclusion

EVAR is less invasive than open repair and useful for treating AAA in octogenarians. Open repair can be acceptable treatment in the unfit case treated by EVAR considering short-term and midterm mortality between EVAR and open repair.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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