Ruptured versus Elective Abdominal AorticAneurysm Repair: Outcome and Cost

Enrico Ascher, MD, Marcel Scheinman, MD, Patrick DePippo, MD, andWilliam Yorkovich, RPA, Brooklyn, New York

During a recent 30-month period, we repaired 10 ruptured abdominal aortic aneurysms (RAAA)at our institution. To evaluate the survival, postoperative morbidity, and financial impact oftreating RAAA, we compared these patients with 10 randomly selected patients undergoingelective AAA (EAAA). Both groups were comparable for age, gender, and incidence of diabetes,hypertension, coronary artery disease, chronic obstructive pulmonary disease (COPD), andrenal failure. Although we have noted a dramatic increase in survival for RAAA (90%), themorbidity continues to be unacceptably high (60%). Efforts should be made toward better de-tection of AAA prior to rupture as well as development of strategies to minimize or prevent thesemajor complications. Potential average savings accrued from one patient undergoing EAAArepair rather than RAAA repair ($93,139.21) can be used to perform screening abdominalultrasound tests in patients at increased risk of having an AAA. (Ann Vasc Surg 1999;13:613-617.)

INTRODUCTION

Although there have been great improvements inoperative technique and postoperative care sincethe repair of the first ruptured abdominal aortic an-eurysm (RAAA) in 1954, death following surgeryremains common.1 Furthermore, 50% of all deathsrelated to RAAA occur prior to arrival at the hospi-tal.2 Patients who survive operative repair have anincreased incidence of major complications such asrespiratory failure, renal failure, sepsis, cardiac fail-ure, bleeding, stroke, ischemic colitis, lower ex-tremity ischemia, and paraplegia. In addition to theincreased morbidity associated with patients whosurvive RAAA, there is a concomitant increase incost to the health care system. This has not been soobvious because of the high mortality associatedwith RAAA. However, as survival improves and as-sociated cost for saving RAAA patients increases,

there is further impetus for early identification ofAAAs and their elective repair. To investigate thishypothesis, we retrospectively reviewed our expe-rience with RAAA to determine how major compli-cations associated with improved survival nega-tively impact cost and compared these results withelective repair. In addition, we investigated wheth-er the price of screening abdominal ultrasound isjustified if patients discovered to have an asymp-tomatic AAA undergo elective (EAAA) repair ratherthan RAAA repair.

PATIENTS AND METHODS

During a 30-month period from January 1993 toJune 1995, 155 patients underwent infrarenal aor-tic aneurysm repair at Maimonides Medical Center,Brooklyn, NY. Ten patients presented with a RAAAon admission. There were seven males and threefemales ranging in age from 65 to 85 years (mean73.4 years). Thirty percent of the patients had ahistory of hypertension (HTN), 10% were diabetic,20% had coronary artery disease (CAD), 20% hadchronic obstructive pulmonary disease (COPD), and

From the Division of Vascular Surgery, Department of Sur-gery, Maimonides Medical Center, Brooklyn, NY.

Correspondence to: E. Ascher, MD, Division of Vascular Sur-gery, 4802 10th Avenue, Brooklyn, NY, 11219, USA.

613

20% had chronic renal failure (CRF). Five patientspresented with an admitting systolic blood pressure(SBP) <90 mmHg and mean admitting SBP was 103mmHg. Nine of the 10 patients had a SBP <90mmHg at least once prior to induction of generalanesthesia. Averaged admitting hematocrit was41.4. Preoperative radiographic testing to confirmthe diagnosis of a RAAA was obtained in four pa-tients, which included one abdominal ultrasound,one abdominal computed tomography (CT) scan,one abdominal X-ray, and one renal scan for a pa-tient thought to be suffering from renal colic. Onepatient had previous knowledge of his AAA andwas taken to the operating room (OR) on the basisof this knowledge and his presentation. Five pa-tients were taken straight to the OR because of pre-sumptive diagnosis and hemodynamic instability.Packed red blood cells (PRBCs), fresh frozen plasma(FFP), and platelets were made available once thediagnosis of RAAA was made.

Once in the OR, patients were stabilized with 2.0L of Ringer’s lactate, prepped, and draped prior toanesthetic induction. Patients who remained hypo-tensive despite 2.0 L of intravenous crystalloid so-lution underwent crash induction. Operative tech-nique included a transperitoneal approach througha midline incision. Supraceliac control was obtainedin 9 out of 10 cases followed by rapid control of theinfrarenal abdominal aorta and removal of the su-praceliac cross-clamp. All patients were heparinizedprior to cross-clamping the aorta to avoid throm-botic complications. Tube grafts were preferentiallyused over bifurcated grafts despite the presence ofsmall iliac artery aneurysms (<3 cm), but iliac arteryaneurysms larger than 3 cm were repaired with abifurcated graft. Care was taken to avoid any majorvenous injury. The cell saver was used in all cases.Hypothermia was avoided by increasing the tem-perature of the OR and ventilated gas, warming in-travenous fluids, use of a forced warm air blanket(Bear Hugger), and warm peritoneal and gastric la-vage when these efforts failed.

Survival, morbidity, and hospital cost of patientstreated for RAAA were compared with that of 10patients randomly selected from those patients who

underwent EAAA repair. The randomization meth-odology was as follows: a list of 145 EAAA repairsdone in chronological order was obtained from thehospital database system. The first patient and everysubsequent 15th patient were selected to ensure aneven time distribution. Demographics for patientsundergoing EAAA repair can be found on Table I.

The costs of major complications such as postop-erative pulmonary failure, pneumonia, cardiac ar-rhythmia, mesenteric ischemia, renal failure, andmyocardial infarction (MI) were recorded. Otherparameters analyzed included length of stay in thesurgical intensive care unit (SICU), days spent in award bed, nursing requirements, medical supplies,laboratory tests, medications, and transfusion ofblood products. Physician fees were excluded. Re-sults were compared using the unpaired Student’st-test and Fisher’s exact test.

RESULTS

Patients in both groups were comparable for age,gender, and incidence of diabetes, HTN, CAD,COPD, and renal function (Table I). All patientswho underwent EAAA repair survived whereasonly one patient who presented with a RAAA diedwithin 30 days of surgery. The operating time forthe RAAA group ranged from 120 to 540 min(mean 348 min). Aortic cross-clamp time for theRAAA group ranged from 25 to 120 min (mean 70min). Neither of these values differed significantlyfrom the EAAA group with means of 259 min op-erating time and 60 min aortic cross-clamp time.Patients undergoing RAAA repair had an averge es-timated blood loss (EBL) of 3.2 L, an average intra-operative fluid requirement of 13.0 L, and an aver-age number of units of PRBCs, FFP, and plateletstransfused during surgery equaling 7.4, 2.2, and6.8, respectively (Table II). These values were sig-nificantly greater than those for patients undergo-ing EAAA repair (p < 0.001).

Eleven major postoperative complications oc-curred in 6 out of the 10 RAAA patients: (1) fivepatients developed pulmonary failure requiringprolonged mechanical ventilation and two of these

Table I. Preoperative risk factors

PatientsAverageage

Averageadmit BP

Hct(%)

HTN(%)

DM(%)

CAD(%)

CRF(%)

COPD(%)

Ruptured 10 73.4 103.3 41.4 30 10 20 20 20Elective 10 70.8 — 40.4 60 10 10 0 0

DM, diabetes mellitus; Hct, hematocrit.

614 Ascher et al. Annals of Vascular Surgery

patients required tracheostomies; (2) two patientshad cardiac arrythmias requiring intravenous anti-arrhythmia medication; (3) two patients developedrenal failure requiring chronic hemodialysis; (4)one patient underwent a Hartman’s procedure formesenteric ischemia; and (5) one patient suffered afatal MI. Five patients who developed complicationssurvived and were discharged from the hospital.Only one patient in the EAAA repair group devel-oped cardiac arrhythmia.

Patients undergoing RAAA repair had a signifi-cantly increased length of stay in the SICU: 21.3days on average for the RAAA group vs. 4.6 days onaverage for the EAAA group (p < 0.001). Averagetime spent on the ward was 20.4 days for the RAAAgroup and 6.9 days for the EAAA repair group (p <0.001).

Intraoperative blood product transfusions, intra-venous crystalloid requirements, and EBL were sig-nificantly higher in the RAAA group (p < 0.001)(Table II). There was no significant difference in theaverage diameter of the aneurysm—8.9 cm for theRAAA group vs. 7.2 cm for the EAAA group.

The greatest difference in cost between the twogroups was attributed to the increased length of stayin the SICU for the RAAA group ($55,380.00 vs.$11,960.00) (Table III). Length of stay in a ward bedalso significantly contributed to the difference incost ($38,950.00 vs. $13,352.40). Unfortunately,average hospital third-party reimbursement forEAAA repair was $26,615.33 and for RAAA repairwas $64,547.25. This represented a net hospital lossof $6,550.58 for EAAA repair and $61,757.87 forRAAA repair.

DISCUSSION

Our experience demonstrates that increased sur-vival from RAAA is associated with increased mor-bidity that leads to a tremendous cost burden on thehealth care system. Ninety percent of patients pre-senting to our institution with a RAAA survived,but at a price of four times that of an EAAA repair.Although developing strategies to minimize major

complications is one obvious solution to decreasecost associated with RAAA, this seems difficult toaccomplish.

The average overall length of stay for a patientundergoing RAAA repair was 42 days whereas pa-tients undergoing EAAA repair stayed 12 days.Most of the increased length of stay can be attrib-uted to a 50% incidence of prolonged respiratoryfailure and a 20% incidence of renal failure requir-ing chronic hemodialysis postoperatively.

Little data have been published addressing thehospital length of stay following RAAA repair. Bushet al.3 point to hypothermia as a major contributoryfactor to prolonged hospital stay (up to 34 days),while Donaldson et al.4 reported a mean hospitalstay of 20 days for RAAA, but with an overall sur-vival of 57%.

Differences in the distribution of risk factors(COPD, CRF, CAD) between the two groups couldnot be determined because of the small number ofpatients in the study. However, the outcome for theEAAA repair group is comparable to that for theremaining 135 EAAA patients operated on duringthe same period (data not shown). Therefore, it isour impression that even if these risk factors werecompared between both groups, the overall out-come would not have been significantly different.

Factors that likely influenced our improved sur-

Table II. Operative blood loss and transfusion requirements

Patients

AverageFFP(units)

Averageplatelets(units)

EB loss(L)

Averageintraoperativefluids (L)

AveragePRBCstransfused(units)

Ruptured 10 2.2 6.8a 3.2a 13.0a 7.4a

Elective 10 0.1 7.2 1.1 6.0 0.3

ap < .001.

Table III. Average hospital cost per AAA

Elective($)

Ruptured($)

Blood products 400.45 2,118.05SICU days 11,960.00 55,380.00SICU medical supplies 92.40 4,132.20SICU labs 1,352.40 6,262.20Ward days 13,352.40 38,950.00Ward supplies 108.10 321.03Ward labs 434.70 1,291.50OR cost 5,465.46 5,697.84Return trips to OR/dialysis 0.00 12,152.30Total 33,165.91 126,305.21

Vol. 13, No. 6, 1999 Ruptured versus elective AAA repair 615

vival were limited intraoperative blood loss withaggressive blood product and fluid replacement.EBL >4.0 L has been found to be associated withincreased mortality.5 Furthermore, increased trans-fusion requirements have also been associated withhigh postoperative mortality.6-8 Patients with bloodtransfusion requirements of >19 units have beenassociated with mortality rates ranging from 83 to100%.7,8 The average EBL for the RAAA group was3.2 L whereas patients undergoing EAAA had anEBL of 1.1 L. Patients in our RAAA group requiredon average 7.4 units of PRBCs in the OR whereaspatients undergoing elective repair averaged 0.3units of PRBCs. In addition, the cell saver was usedin all cases.

Other risk factors that have been found to influ-ence early complications and death are duration ofcross-clamp time, preoperative shock, use of a su-prarenal cross-clamp, and a history of CAD.9 Post-operative complications associated with early deathare myocardial failure, sepsis, renal failure, and co-lon ischemia.10

There was no significant difference in aorticcross-clamp time between the RAAA group and pa-tients undergoing EAAA repair. We used a supra-renal clamp in 9 out of 10 patients with a RAAA.Decreased intraoperative blood loss, transfusion re-quirement, and intraoperative hypotension couldbe attributed to the use of the suprarenal clamp.Preoperative hypotension is the most frequentlycited prognostic factor, associated with decreasedsurvival and early death.7,8,11,12 In our series fivepatients from the RAAA group presented with anadmitting SBP <90 mmHg and the mean admittingSBP for this group equaled 103 mmHg. Nine out of10 patients had a SBP of <90 mmHg at least onceprior to induction of general anesthesia. Some prac-titioners have theorized that use of a suprarenalclamp causes increased myocardial strain due to arapid rise in SBP and subsequent increased cardiacmorbidity and mortality. Other disadvantages to su-praceliac clamping include mesenteric and renalischemia. We had one case of mesenteric ischemiarequiring a Hartman’s procedure, one fatal MI, andtwo cases of CRF requiring hemodialysis. It is notclear whether these complications were due to theuse of a supraceliac clamp or preoperative hypoten-sion combined with pre-existing atherosclerotic oc-clusive disease. We find that the benefits of hemo-dynamic stability offered by expeditious supraceliaccross-clamping outweigh the risk of ischemic com-plications that may be associated with its use.

Operative duration for RAAA has also beenfound to correlate with mortality. Operations last-ing longer than 300 min had a significantly higher

mortality compared to operations that lasted 120 to180 min.5 Others have reported 100% mortality foroperations over 400 min.13 The average time spentin the OR for the RAAA group was 384 min whileactual operating time was 348 min. This was notstatistically different from the operating time for pa-tients undergoing EAAA repair. Factors that re-duced operative time and, more importantly, aorticcross-clamp time were preferential use of tubegrafts despite the presence of limited iliac aneu-rysms (<3 cm) and experienced vascular surgeons.In addition, there were no major intraoperativecomplications such as cardiac arrest,14,15 venous in-jury,12 and intestinal or splenic injury.4

Hypothermia is a problem frequently encoun-tered in patients undergoing RAAA repair and hasbeen found to be associated with coagulopathy, aci-dosis, and decreased oxygen delivery.3 We avoidedintraoperative hypothermia in our patients, andthis may have contributed to a better outcome.

Beside all the aforementioned measures thatmay have contributed to a better outcome, the highrate of 90% survival in this series may also be duein part to the small number of patients in the seriesrather than other innovative care practice.

Although survival was improved dramatically inthis cohort of RAAA patients, there was a high fre-quency of major complications with associated in-creased cost compared to individuals undergoingEAAA repair. The most effective means to reducemorbidity and cost from RAAA may be screeningpatients at high risk for AAA and offering electiverepair to these individuals prior to rupture.

The incidence of AAA for men age 60 and greateris estimated to be between 2.0% and 7.8%.16 Indi-viduals with additional risk factors such as smoking,HTN, or atherosclerotic vascular disease have ahigher prevalence.17 Overal, approximately 6% ofaneurysms >4 cm in diameter will rupture annu-ally,18 and RAAA is reported to cause 1.2% of maledeaths and 0.6% of female deaths of individualsolder than 65 years in the United States.19

Sensitivity of the physical exam in detectingAAA has ranged from 22 to 96%. Thus, a physicalexam cannot be relied on to effectively screen pa-tients suspected of having an AAA.

Ultrasonography is a reliable test for detectingAAA, with sensitivity rates of between 82 and99%.20 Wolf et al.21 recently reported a 3.2% inci-dence of an AAA 4.0 cm or greater in 475 patientsscreened for AAA during lower extremity arterialevaluation in the vascular laboratory. Screening forAAA in male smokers over age 65 in this same pa-tient population yielded a prevalence of 8.8%. Thecost of identifying an aneurysm of 4.0 cm or greater

616 Ascher et al. Annals of Vascular Surgery

ranged from $561 to $1603, depending on the se-lection of the population to be screened. These fig-ures compare favorably with the cost of identifyinga single breast cancer, which is estimated at $23,000with the use of physical exam and screening mam-mography.22

The familial tendency of AAA has been noted byClifton,23 Tilson et al.,24 and most recently by Web-ster et al.25 In Webster’s study, AAA was found in8.2% of first-degree relatives over age 55. Clearlythere are select patient populations that have anincreased incidence of AAA. This would includemales over age 65 with a history of symptomaticlower extremity vascular disease, carotid occlusivedisease, tobacco use, or family history of an AAA.Screening this population wtih abdominal ultra-sound would be justified to preferentially repairAAA prior to rupture.

REFERENCES

1. Johansen K, Kohler TR, Nicholls C, Zierler RE, Clowes AW,Kazmers A. Ruptured abdominal aortic aneurysm: the Har-borview experience. J Vasc Surg 1991;13:240-247.

2. Johannson G, Swedenborg J. Ruptured abdominal aortic an-eurysm: a study of incidence and mortality. Br J Surg 1986;73:101-103.

3. Bush HL Jr, Hydo LJ, Fischer E, Fantini GA, Silane MF, BariePS. Hypothermia during elective abdominal aortic aneurysmrepair: the high price of avoidable morbidity. J Vasc Surg1995;21:392-402.

4. Donaldson MC, Rosenberg JM, Bucknam CA. Factors affect-ing survival after ruptured abdominal aortic aneurysm. JVasc Surg 1985;2:564-570.

5. Hidebrand HD, Fry PD. Ruptured abdominal aortic aneu-rysm. Surgery 1975;77:540-544.

6. Morris PJ, Buxton BF, Flac C. Ruptured abdominal aorticaneurysms presenting to a general hospital. Med J Aust1975;1:555-558.

7. Sink JD, Myers RT, James PM. Ruptured abdominal aorticaneurysms: review of 33 cases treated surgically and discus-sion of prognostic indicators. Am Surg 1976;42:303-307.

8. VanHeeckeren DW. Ruptured abdominal aortic aneurysm.Am J Surg 1970;119:402-407.

9. Bauer EP, Redaelli C, von Segesser LK, Turina MI. Rupturedabdominal aortic aneurysms: predictors for early complica-tions and death. Surgery 1993;114:31-35.

10. Ouriel K, Geary K, Green RM, Fiore W, Geary JE, DeWeeseJA. Factors determining survival after ruptured aortic aneu-rysm: the hospital, the surgeon and the patient. J Vasc Surg1990;11:493-496.

11. Chiariello L, Reul Jr GJ, Wukasch DC, et al. Ruptured ab-dominal aortic aneurysm: treatment and review of eighty-seven patients. Am J Surg 1974;128:735-738.

12. DiGiovanni R, Volpetti R, Berkowitz H, et al. Twenty-oneyears’ experience with ruptured abdominal aortic aneu-rysms. Surg Gynecol Obstet 1975;141:859-862.

13. Wakefield TW, Whitehouse WM, Wu SC, et al. Abdominalaortic aneurysm rupture: statistical analysis of factors affect-ing outcome of surgical treatment. Surgery 1982;91:586-596.

14. Gardner RJ, Gardner NL, Tarnam TJ, et al. The surgical ex-perience and a one to sixteen year follow-up of 277 abdomi-nal aortic aneurysms. Am J Surg 1978;135:226-230.

15. Lawrie GM, Morris Jr GC, Crawford ES, et al. Improvedresults of operation for ruptured abdominal aortic aneu-rysms. Surgery 1979;85:483-488.

16. O’Kelly TJ, Heather BP. General practice-based populationscreening for abdominal aortic aneurysms: a pilot study. BrJ Surg 1989;76:479-480.

17. Ballard DF, Etchason JA, Hilborne LH, et al. Abdominal aor-tic aneurysm surgery: a literature review and ratings ofappropriateness and necessity. Santa Monica, CA: RAND,1992, JRA-04.

18. Cronenwett JL, Murphy TF, Zelenock GB, et al. Actuarialanalysis of variables associated with rupture of small ab-dominal aortic aneurysms. Surgery 1985;98:472-483.

19. Vital Statistics of the United States, 1974, Mortality, Vol. 2,part A. Washington, DC: U.S. Department of Health Educa-tion and Welfare, 1974, Publication no. PHS 79-1101.

20. Quill DS, Colgan MP, Sumner DS. Ultrasonic screening forthe detection of abdominal aortic aneurysms. Surg Clin ofNorth Am 1989;69:713-720.

21. Wolf GW, Otis SM, Schwend RB, Bernstein EF. Screeningfor abdominal aortic aneurysms during lower extremity ar-terial evaluation in the vascular laboratory. J Vasc Surg1995;22:417-423.

22. Russell JGB. Is screening for abdominal aortic aneurysmworthwhile? Clin Radiol 1990;41:181-184.

23. Clifton MA. Familial abdominal aortic aneurysms. Br J Surg1977;64:765-766.

24. Tilson MD, Seashore MR. Fifty families with abdominal aor-tic aneurysms in two or more first order relatives. Am J Surg1984;147:551-553.

25. Webster MW, Ferrell RE, St. Jean PL, Majumder PP, FogelSR, Steed DL. Ultrasound screening of first degree relativesof patients with an abdominal aortic aneurysm. J Vasc Surg1991;13:9-14.

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