Outcomes of Ruptured Aortic Aneurysm: Early and Late



Fig. 17.1
A uniform triage protocol was established for endovascular repair of ruptured abdominal aortic aneurysms (rAAA). ER emergency room, CTA computed tomography angiography, BP blood pressure, EVAR endovascular aneurysm repair



Starnes and colleagues published a comparative experience, before and after implementation of a standardized protocol for management of rAAA [11]. In the era prior to implementation of a standardized protocol that incorporated preferential treatment with endovascular repair, the 30-day mortality was 57.8 %, compared with 35.3 % (p = .008) in the protocol era. After implementation of the standardized protocol, 48 % of patients underwent EVAR for rAAA, in contrast to <1 % (1 of 131) prior to implementation of the standardized protocol. The authors conclude that the survival benefit was due to both the adoption of a standardized protocol, as well as to the use of EVAR.

The benefits of a structured protocol for the diagnosis and management of rAAA are now so well recognized that it has been cited by some as a potential confounder in the assessment of the benefit of EVAR compared with open repair [12, 13]. In reviewing the literature, it can be difficult to separate the benefit from having a structured protocol in place from the potential benefit of EVAR compared to open surgery. The use of such protocols should be widely adopted [14].



Outcomes from Retrospective Studies


The majority of data on rAAA outcomes is derived from a variety of retrospective studies (case series, registries, large databases), which is common for emergent diagnoses such as this. Several authors have made efforts to correct for bias and confounding by using multivariable regression, propensity score matching, and subgroup analyses. Despite the retrospective nature of these data, the large body of published work has allowed for the performance of carefully structured meta-analyses and systematic reviews.


Open Repair


In 2008, Hoornweg and colleagues published a systematic review and meta-analysis of 116 studies from 1991 to 2006 on open repair of rAAA [15]. They sought to evaluate trends in mortality over time, as well as the effect of hospital volume on outcomes. Among approximately 60,000 patients, the weighted mean overall perioperative mortality was 48.5 % (95 % CI, 48.1–48.9 %). The intraoperative mortality was reported in 37 studies, and the weighted mean was 13.3 % (95 % CI, 12.3–14.3 %). Over the 33 years of study, there was no significant change in overall mortality as a function of time (1.6 % reduction, p = NS). Analysis of the 58 studies that included hospital volume revealed a significant positive association between annual hospital volume of rAAA repairs and overall mortality (p = .04). Unfortunately, the authors were unable to determine a threshold of rAAA hospital volume that is associated with improved mortality. Despite the limitations inherent to this study, the inclusion of over 60,000 patients provides valuable data on outcomes following open repair of rAAA (Fig. 17.2).

A328912_1_En_17_Fig2_HTML.gif


Fig. 17.2
Meta-regression of 69 studies reporting on % overall mortality (Y axis) against hospital volume (X axis) with 95 % CI


Endovascular Repair


In 2008, Mastracci and colleagues published a systematic review and meta-analysis of 18 studies between 1994 and 2006 on endovascular repair (EVAR) of rAAA [13]. The pooled mortality was 21 % (95 % CI, 13–29), with a broad range of reported outcomes across studies (0–45 % mortality). In fact, the authors conclude that in the presence of such substantial heterogeneity, the aggregated calculated point estimate cannot be considered reliable. Subgroup analyses that included only series where >30 cases were reported demonstrated a reduction in heterogeneity and a mortality of 19 % (95 % CI, 10–28). While EVAR for rAAA is widely practiced, rigorous analysis and interpretation of its results have been difficult.


Comparison of Open and Endovascular Repair


Several advantages of EVAR for rAAA repair compared to open surgery have been published, but the retrospective and other non-randomized study designs have been criticized for the potential selection bias that may be inherent to these studies. The primary concern has been that patients selected for EVAR may be more stable at their time of presentation, and this increased stability may be responsible for improved outcomes. In 2009, Hinchliffe and colleagues published a systematic review of the literature on EVAR for rAAA, specifically noting those that contained a “control” open repair group [12]. Despite having adopted EVAR for treatment of many patients with rAAA at the authors’ center, they conclude that the evidence for its benefit is lacking. Conflicting results have been reported, and questions regarding the comparability of the two patient groups remain (Table 17.1).


Table 17.1
Data from published series from 1994 to 2009 where outcomes of endovascular repair for ruptured abdominal aortic aneurysms were compared with a control group undergoing open surgery




































































































































































































































First author

Year

Study type

Patients treated by EVAR, No.

30-day mortality, %

P

EVAR

Open repair

Acosta

2007

Retrospective review

56

34

45

.16

Alsac

2005

Case series

17

23.5

50

.09

Anain

2007

Retrospective review

30

17

40

.19

Arya

2006

Prospective intent-to-treat

17

24

47

.14

Brandt

2005

Retrospective review

11

0

15

NS

Castelli

2005

Retrospective review

25

20

25

NS

Coppi

2006

Retrospective review

33

30

46

NS

Franks

2006

Retrospective study

21

11

54

NS

Hechelhammer

2005

Retrospective study

35

10.8

35

NS

Hinchliffe

2006

Prospective randomized

15

53

53

NS

Kapma

2005

Retrospective study

40

13

30

NS

Lee

2004

Retrospective study

13

4.69

25

NS

Mehta

2006

Prospective observation

40

18

51


Moore

2007

Prospective observation

20

5

25

NS

Najjer

2007

Retrospective review

15

6.7

13.6

NS

Ohki

2000

Retrospective study

18

10

0

NS

Ockert

2007

Retrospective review

29

31

31

<.99

Peppelenbosch

2003

Prospective study

26

31

50

NS

Scharrer-Pamler

2003

Retrospective review

24

20.8

40

NS

Vaddenini

2005

Retrospective study

9

22

26

NS

Visser

2006

Retrospective review

26

31

31

NS

Wibmera

2008

Retrospective review

16

25a

29a

NS

Yilmaz

2002

Retrospective review

24

17

34

NS

Peppelenbosch

2006

Prospective study

49

35

39

NS

Verhoeven

2009

Prospective observation

36

28.1

13.9

.092

Sadat

2009

Prospective observation

17

6

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Nov 11, 2017 | Posted by in ABDOMINAL MEDICINE | Comments Off on Outcomes of Ruptured Aortic Aneurysm: Early and Late
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