Ruptured Abdominal Aortic Aneurysm: DoesTrauma Center Designation Affect Outcome?

Farida Bounoua,1 Rob Schuster,1 Prabhjot Grewal,1 Kenneth Waxman,1

and Paul Cisek,2 Santa Barbara, California

Ruptured abdominal aortic aneurysm (RAAA) continues to be a major cause of mortality in theUnited States. Rapid diagnosis and uncomplicated surgical repair remain paramount to improv-ing survival in this population. We proposed that the addition of an organized trauma service andsubsequent improved management of critically ill patients who present with RAAA would posi-tively impact overall mortality. A retrospective analysis was performed on all patients treatedfor RAAA at Santa Barbara Cottage Hospital for the years 1985-2004. Patients treated beforelevel II trauma center designation (1985-1999) were compared to those treated after the traumacenter was instituted. A total of 76 patients were included in this analysis. The two groups weresimilar with regard to demographics. However, significant decreases in transport time from theemergency department to the operating room and overall 30-day mortality were seen in patientsafter the trauma center designation. This designation also led to an increase in the number ofcases performed per year, centralizing the treatment for these critically ill patients. Institutionof a well-prepared and organized service, such as trauma, improved the outcome for patientstreated with RAAA, with a particular benefit in the unstable patient.

INTRODUCTION

Ruptured abdominal aortic aneurysm (RAAA) con-

tinues to be a major cause of mortality in the United

States. RAAA currently ranks fifteenth among all

causes of death for men in the United States each

year.1 Expedient diagnosis and uncomplicated sur-

gical repair remain of paramount importance to im-

proving the chances of survival in this population.

However, even with advances in surgical and perio-

perative care, RAAA is associated with a mortality

rate of 45-58% and an overall mortality of 75-

90%, including prehospital deaths. These dismal

Presented at the 23rd Annual Meeting of the Southern CaliforniaVascular Surgical Society, La Quinta, CA, May 13-15, 2005.

1Department of Surgery Santa Barbara Cottage Hospital, SantaBarbara, CA, USA.

2Department of Vascular Surgery, Sansum Santa Barbara MedicalFoundation Clinic, Santa Barbara, CA, USA.

Correspondence to: Paul Cisek, MD, Sansum Santa Barbara Clinic,317 West Pueblo Street, Santa Barbara, CA 93105, USA, E-mail:Pcisek@sansumclinic.org

Ann Vasc Surg 2007; 21: 133-136DOI: 10.1016/j.avsg.2007.01.003� Annals of Vascular Surgery Inc.Published online: March 9, 2007

mortality rates have not significantly improved in

the past 20 years.1-5 Many factors have been dis-

cussed in the literature with regard to predicting

mortality in patients with RAAA. These factors in-

clude blood pressure, hemoglobin level, creatinine

level, blood transfusion requirement, temperature,

cardiac arrest, acidosis, age, and female gender.6-8

Certainly, all physicians treating RAAA agree that

these patients need operative intervention as

quickly as possible since delays in transport to the

operating room are associated with increased

mortality.9 This often requires an organized team

approach with designated operating rooms and staff

for support.

Santa Barbara Cottage Hospital is a 350-bed com-

munity teaching hospital. In 1999 the hospital was

first designated as a level II trauma center by the

American College of Surgeons. In order to achieve

and maintain this designation, a dedicated trauma

team consisting of a surgeon, resident physician

staff, anesthesiology, neurosurgery, orthopedics,

on-call nurses, and ancillary staff must be well pre-

pared to rapidly assess and treat critically ill patients.

Although not specifically designed to treat vascular

emergencies, this team remains equipped to handle

all surgical emergencies.

133

134 Bounoua et al. Annals of Vascular Surgery

We proposed that the addition of this organized

trauma service and subsequent improved manage-

ment would positively impact overall mortality for

patients presenting with RAAA.

METHODS

A retrospective analysis was performed for all pa-

tients treated for RAAA at Santa Barbara Cottage

Hospital between February 1985 and December

2004. All patients refusing surgical intervention

were excluded. After institutional review board

approval, all patient charts were reviewed based

on Current Procedural Terminology (CPT) codes

for ruptured infrarenal AAAs. Demographic and

preoperative factors recorded included age, sex, co-

morbidities, blood pressure, and transport time from

the emergency department to the operating room.

In addition, intraoperative and postoperative data

were gathered. Primary outcome was 30-day

mortality.

The patients were stratified into two groups:

those treated from 1985 to 1999 before the level II

trauma center designation (group I) and those

treated after the designation (group II). The patients

were further evaluated with respect to hemody-

namic status on arrival as stable versus unstable.

Unstable patients were defined as those with a re-

corded systolic blood pressure of<90 mm Hg on pre-

sentation to the emergency room. In addition,

distance traveled to the hospital was recorded.

Data were analyzed using GraphPad� (GraphPad,

San Diego, CA) software. Groups were compared

using Student’s two-tailed t-test. Statistical signifi-

cance was achieved at P < 0.05.

RESULTS

A total of 100 patients were treated at our institution

for RAAA from 1985 to 2004. Twenty-four patients

refused treatment, and all expired. The remaining

76 patients underwent open repair of RAAA and

are the focus of this report.

Group I consisted of 44 patients with RAAA

treated from 1985 to 1999 and group II consisted

of 32 patients cared for after 1999 when the level

II trauma center was instituted. Demographics of

the groups are depicted in Table I. The groups

were equivalent regarding age, sex, and comorbid

factors. In addition, presence of hemodynamic

instability did not significantly differ between the

groups: 14 patients in group I and 10 patients in

group II.

The mean time to transfer to the operating room

and 30-day mortality are shown in Table II. A de-

crease in time from the emergency room to the op-

erating room was seen after level II trauma center

designation. In addition, an improvement in

30-day mortality was seen in patients treated for

RAAA after level II trauma center designation.

Further stratification into hemodynamic stability

is shown in Tables III and IV. Hemodynamic insta-

bility was defined as admission systolic blood pres-

sure <90 mm Hg. A significant improvement in

time to the operating room from the emergency de-

partment was seen with both stable and unstable pa-

tients after the level II trauma center designation.

The 30-day mortality in unstable patients was also

improved. This same improvement in mortality

was not significant in stable patients presenting

with RAAA. There were no differences in the mor-

tality of patients when analyzed for distance trav-

eled to the hospital.

Although there was an increase in the number of

RAAA cases treated per year, three per annum in

group I and eight per annum in group II, no differ-

ence was seen in individual surgeons who operated

in both time periods regarding 30-day mortality.

DISCUSSION

Continued high mortality rates for patients treated

for RAAA has been the subject of much debate.

Even with advances in operative and perioperative

care, mortality still frequently approaches 70%.1-5

These poor results have prompted authors to evalu-

ate factors associated with mortality and to consider

nonoperative therapy. These include initial blood

pressure, hemoglobin level, creatinine level, blood

transfusion requirement, temperature, cardiac ar-

rest, acidosis, age, and female gender.6-10 In addi-

tion, presence of medical comorbidities has been

evaluated.

Table I. Demographics

Characteristic Group I Group II

Number of

patients

44 32

Unstable patients 14 10

Male gender (%) 70 75

Mean age (years) 78.3

(range 53-94)

73.2

(range 60-94)

Diabetes (%) 20 21

Hypertension (%) 65 67

Coronary artery

disease (%)

25 22

Vol. 21, No. 2, 2007 RAAA and trauma center designation 135

All authors agree that rapid transport, evaluation,

and uncomplicated operative treatment of RAAA

remain of paramount importance to optimizing sur-

vival in these patients. A delay in diagnosis in the

emergency department was associated with in-

creased mortality in a previous study by Pannetan

and colleagues.11 Increased time in the operating

room was also associated with increased mortality

in a study by Wakefield et al.,12 with >4 hr operat-

ing time being a significant predictor of mortality.

Our study sought to evaluate the treatment of

critically ill patients with a diagnosis of RAAA.

More specifically, we evaluated the outcome in pa-

tients treated with RAAA before and after designa-

tion as a level II trauma center. This requires an

institution to have a 24 hr call team consisting of

a general surgeon, specialty surgeons, resident staff,

nurses, and ancillary services. This team is prepared

to handle trauma cases. In addition, a secondary

benefit of this organized team is to improve care of

other surgical emergencies such as RAAA. Both

trauma patients and unstable surgical patients are

assessed and treated quickly by in-house resident

physician staff. Operating room facilities and staff

are then rapidly mobilized.

Our analysis showed a significant improvement

in outcome after the trauma center designation. De-

creased transport time from the emergency depart-

ment to the operating room was seen for all

patients regardless of hemodynamic stability. In ad-

dition, 30-day mortality was significantly improved

in patients treated for RAAA after trauma center

designation. This was not significant for patients

presenting with a stable hemodynamic profile.

One reason for the decreased mortality after the

trauma center designation was the decreased time

to the operating room. Two other recognized factors

for improved outcome were also identified. First,

Table II. Overall time to the operating room and

30-day mortality

Characteristic Group I Group II P

Time to the OR (min) 125 80 0.001

30-day mortality (%) 73.5 46.8 0.02

Table III. Stable patients

CharacteristicGroup I(n ¼ 30)

Group II(n ¼ 22) P

Time to the OR (min) 144 103 0.01

30-day mortality (%) 63 40 0.057

several studies have shown that increased volume

in both the center itself and individual surgeons

lead to improved outcome in patients with

RAAA.9,11 In 1997, a fellowship-trained vascular

surgeon joined our community with an increased

volume of elective aortic aneurysm repairs. Al-

though the outcome for those patients treated for

RAAA by this surgeon was improved compared to

the other surgeons, this variable did not reach signif-

icance. In addition, the volume of patients treated

for RAAA increased after the level II trauma center

designation. This volume more than doubled to

eight RAAAs per year. Once again, this was a prod-

uct of centralization of care for these critically ill

patients to our institution. This effect has been

documented in other reports.8

Overall, RAAA carries a significant mortality,

and optimizing care is critical to improving mortal-

ity rates. Our data clearly show the benefit of an or-

ganized service to centralize the management of

these critically ill patients. This allows rapid utiliza-

tion of resources and hastens time to the operating

room, resulting in an improvement in overall sur-

vival. Although a designated trauma service may

not be feasible for every community hospital, we

have demonstrated the importance of having

a well-prepared service to improve the outcome in

patients with RAAA. The study supports the im-

provement in patient survival related to increased

case volume, with the greatest benefit for the unsta-

ble patient.

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CharacteristicGroup I(n ¼ 14)

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136 Bounoua et al. Annals of Vascular Surgery

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