Early and late outcome of surgical repair for small abdominal aortic aneurysms: A population-based analysis

Improvement in results of repair of type IV thoracoabdominal aortic aneurysms

PURPOSE

Although management of extensive type I and II thoracoabdominal aortic aneurysms (TAA) remains a formidable challenge, results of repair of TAA originating in the distal thoracic aorta (type IV) appear to have improved significantly. To quantitate this perceived improvement, the following retrospective study was undertaken to examine the results of type IV TAA repair at the Brigham & Women's Hospital over the past 18-year period.

METHODS

From July 1977 to September 1994, nonruptured atherosclerotic type IV TAAs were repaired in 58 patients. The mean age was 70 years, and associated risk factors included smoking (91%), hypertension (86%), coronary artery disease (52%), and previous aortic surgery (38%). Mean follow-up was 2.4 years (median 2 years).

RESULTS

Overall 30-day mortality was 5.3% (two deaths). Morbidity included stroke (3.5%), paraplegia (1.8%), permanent paraparesis (1.8%), myocardial infarction (7%), pneumonia (8.8%), gastrointestinal bleeding (11%), intestinal ischemia (5.3%), wound infection (7.0%), peripheral ischemia (5.3%), in-hospital dialysis (8.8%), and permanent dialysis (1.9%). Overall 5-year survival was 50%. With univariate analysis, survival was positively correlated with more recent year of operation (p = 0.002), smaller volume of intraoperative blood transfusion (p = 0.02), decreased supraceliac ischemia time (p = 0.04), and the use of the retroperitoneal approach (p = 0.09). Multiple regression analysis revealed that the year of operation was the only independent predictor of survival (p = 0.003). Subgroup analysis of patients who underwent operation between 1977 and 1987 (n = 13) and 1988 and 1994 (n = 45) revealed statistically significant improvements in length of hospital stay (46 +/- 12 vs 21 +/- 4 days, p = 0.02), postoperative dysrhythmia (50% vs 16%, p = 0.03), postoperative maximum serum glutamic oxaloacetic-transaminase (516 +/- 234 vs 319 +/- 139 mg%, p = 0.04), incidence of hemorrhage requiring reexploration (33% vs 0%, p = 0.002), 30-day mortality (23% vs 0%, p = 0.009), and in-hospital mortality (39% vs 2.2%, p = 0.002).

CONCLUSIONS

The modern mortality, morbidity, and survival of surgical repair of type IV TAA in our institution approaches that of infrarenal abdominal aortic aneurysm.

Hospital volume, calendar age, and short term outcomes in patients undergoing repair of abdominal aortic aneurysms: the Ontario experience, 1988-92

OBJECTIVE

To determine, for abdominal aortic aneurysm surgery, whether a previously reported relationship between hospital case volume and mortality rate was observed in Ontario hospitals and to assess the potential impact of age on the mortality rate for elective surgery.

DESIGN

Population based observational study using administrative data.

SETTING

All Ontario hospitals where repair of abdominal aortic aneurysm as a primary procedure was performed during 1988-92.

PATIENTS

These comprised 5492 patients with unruptured abdominal aortic aneurysms and 1203 patients with ruptured abdominal aortic aneurysms admitted to hospital between 1988-92 for repair of abdominal aortic aneurysm as a primary procedure.

MAIN OUTCOMES

In-hospital death and length of in-hospital stay.

RESULTS

The case fatality rate was 3.8% for unruptured abdominal aortic aneurysms and 40.0% for ruptured abdominal aortic aneurysms. For unruptured cases, after adjustment for patient and hospital covariates, each 10 case per year increase in hospital volume was related to a 6% reduction in relative odds of death (odds ratio (OR) 0.94, 95% confidence intervals 0.88, 0.99) and 0.29 days reduction (95% CI -0.22, -0.35) in postoperative in-hospital stay. Female sex (OR 1.53, 95% CI 1.08, 2.18) and transfer from another acute care hospital (OR 4.37, 95% CI 2.62, 7.29) were associated with increased case fatality rates among patients in the unruptured category. For ruptured cases, neither the case fatality rate nor postoperative in-hospital stay were significantly related to hospital volume. The case fatality rates increased linearly and substantially with advancing age both for unruptured and ruptured aneurysms, and the excess risk of postoperative death in ruptured as compared to unruptured aneurysms was substantially higher in older patients.

CONCLUSION

The relationship between hospital volume and mortality or morbidity was very modest and observed only for elective surgery. Case fatality rates in patients with ruptured abdominal aortic aneurysms remained 10 times higher than for patients with unruptured abdominal aortic aneurysms, despite improvements in overall mortality in comparison to previously published data. More effective detection of aneurysms, including elective repair for those once considered "high risk" older patients, might further reduce the toll from ruptured aortic aneurysms.

Hospital based screening of 65-73 year old men for abdominal aortic aneurysms in the county of Viborg, Denmark

OBJECTIVE - To analyse the benefits of screening older men for abdominal aortic aneurysms. METHODS - A hospital based screening trial concerning 13 500 65-73 year old men using B-mode ultrasonographic scanning. To improve the response rate the invited men could change their appointment, and nonresponders were reinvited. RESULTS - Results from the first year of the trial are presented. Among 4404 invited, 3344 (76%) were scanned. The primary response rate was 64.8%, but a further 11.2% were scanned after revised appointments or reinvitation. The whole infrarenal aorta could be visualised in 97-6%, and the distal part in 99.7% of the scans. The time taken for each scan was 9-7 minutes and the costs per scan were $9.50. One hundred and fifty three subjects (4.6%) had aortic diameters of 25-29 min, and 141 (4.2%) had an abdominal aortic aneurysm, 19 (0.6%) above 49 mm in diameter. CONCLUSION - In Denmark the short term costs and benefits of screening older men for abdominal aortic aneurysms seem realistic. Long term costs and benefits need to be investigated.

Early experience with transfemoral endovascular aneurysm management (TEAM) in the treatment of aortic aneurysms

OBJECTIVES

To evaluate the early experience with transfemoral endovascular aortic aneurysm management using the Endovascular Grafting System.

DESIGN

Multi-centre prospective evaluation of the implantation procedure and early results (median follow-up 153 days).

SETTING

Department of Surgery, University Hospital Utrecht, The Netherlands; Department of Surgery, University of Sydney, Australia; University of Leicester School of Medicine, Leicester, U.K., Department of Surgery, Karolinska Hospital, Stockholm, Sweden and Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital; Oxford, U.K.

MATERIALS

31 consecutive patients treated in 13 months. CHIEF OUTCOME MEASUREMENTS: Peri and postoperative morbidity and mortality in accordance with the recommendations of the Ad Hoc Committee on Reporting Standards.

MAIN RESULTS

Graft placement was initially successful in all 31 patients. In one patient the endograft had to be replaced by a standard aortic tube graft because of extra graft flow in the aneurysm sac, and complaints of back pain. One patient died from multiple organ failure, 11 days after the operation. In three patients five severe adverse events were recorded. Breaks of the attachment system were encountered in two patients. These failures did not have severe clinical consequences for individual patients.

CONCLUSIONS

Transfemoral Endovascular Aneurysm Management is a technically demanding procedure that requires special training in both catheter and surgical techniques. The potential for less operative morbidity when compared to conventional surgery and the prospect of technical improvements in graft and introduction system design will make TEAM an important tool in aneurysm management in the near future.

Selective management of abdominal aortic aneurysms in a prospective measurement program

PURPOSE

The purpose of this study was to clarify the treatment of patients with small abdominal aortic aneurysms (AAAs) less than 5 cm in diameter and those believed to be unfit for operation with AAAs 5 cm diameter or greater.

METHODS

Four hundred ninety two patients with AAAs less than 5 cm when first seen were entered in a prospective measurement program by ultrasonography or computed tomography scan (exclusively after 1998) every 6 months. A decision regarding operative fitness was made when the AAA was 5 cm. Patients then underwent operation if fit or continued follow-up if their AAA was larger than 5 cm but they were unfit. A further group of 91 patients with aneurysms 5 cm or greater when first seen but unfit for repair were entered in the prospective measurement program.

RESULTS

In the group with AAAs less then 5 cm at entry, operation was performed in 201 patients as a result of increase in AAA size to 5 cm or greater (157), AAA expansion of more than 0.5 cm in 6 months (24), or for other reasons (20). Of those with AAAs smaller than 5 cm at entry, 291 have not undergone operation at a mean follow-up of 42 months. Expansion was significantly related to aneurysm size at entry and was highest in the 4.5 to 4.9 cm group at 0.7 cm/year. In the group of patients deemed unfit for operation with 5 cm AAAs [as a graduate of the less than 5 cm group at entry (85 patients) or first seen with AAA greater than 5 cm (91 patients)], 10 ruptures have occurred. Of these patients with ruptured AAAs, six had AAAs between 5.0 and 5.6 cm.

CONCLUSIONS

Because of the risk of rupture demonstrated in our series in AAAs 5 cm or slightly greater and the progressive increase in expansion to a mean of 0.7 cm/year in those AAAs between 4.5 and 4.9 cm at entry, recommendation for elective operation in patients with AAAs between 4.5 and 4.9 cm at entry, recommendation for elective operation in patients with AAAs between 4.5 and 5.0 cm should be strongly considered in a fit patient.

Simultaneous abdominal aortic aneurysm repair and nephrectomy for neoplasm

BACKGROUND

Abdominal aortic aneurysm and renal neoplasm are occasionally discovered concurrently. Simultaneous operative therapy may be an effective alternate management strategy to a staged procedure.

PATIENTS AND METHODS

The medical records of 10 consecutive patients undergoing abdominal aortic aneurysm repair and nephrectomy for renal neoplasm were reviewed. Data collected included mode of presentation, preoperative evaluation, renal pathology, and in-hospital morbidity and mortality. Long-term follow-up was obtained through office records and telephone contact.

RESULTS

In 7 patients, the renal mass was identified during evaluation of abdominal aortic aneurysm. The aneurysm was identified during evaluation of hematuria in 2 patients. One patient was discovered to have both conditions simultaneously. All patients underwent successful aneurysm repair and nephrectomy. Pathology revealed 6 renal cell carcinomas, 2 complex cysts, 1 hemangiopericytoma, and 1 oncocytoma. Four patients have died in the follow-up period: 1 of metastatic cancer and 3 of unrelated causes. There have been no cases of graft infection.

CONCLUSION

Simultaneous abdominal aortic aneurysm repair and nephrectomy for neoplasm is an appropriate management strategy for selected patients.

Morphology of small aneurysms: definition and impact on risk of rupture

BACKGROUND

Parietal characteristics of small aortic aneurysms predictive of increased risk of rupture are unknown.

METHODS

Prospective morphologic evaluation was performed in 135 consecutive cases of small (< 5 cm) abdominal aortic aneurysm. Twelve cases (9%) were found to be ruptured and sent for emergency surgery. The remaining 123 patients were evaluated with ultrasonography, angiography, and intraoperatively during elective surgery. Ninety-six (78%) also underwent computerized tomography (CT) scanning. The evaluation assessed the thickness of the endoluminal thrombus and arterial wall as well as the presence of saccular outpouchings ("blisters"). Also noted were any areas of impending rupture, defined as discontinuity of the arterial wall with only a thrombus preventing rupture.

RESULTS

Blisters were discovered intraoperatively in 12 aneurysms. Digital subtraction angiography (DSA) revealed 3 (25%) of these preoperatively. Eleven of the patients with blisters were examined preoperatively with CT scanning, which detected 3 blisters (27%). Both endoluminal thrombus and wall thickness were measurable by CT scan but not ultrasonography. The incidence of impending rupture was significantly greater in patients with blisters than in those without (71% versus 29%, P = 0.0001). The incidence of impending rupture was similar whether the amount of endoluminal thrombus was more or less than 2 cm (57% versus 40%, P = 0.386). Rupture was no more frequent when aneurysmal walls were thicker or thinner than 0.3 cm (14% versus 20%, P = 0.719). In an analysis using logistic regression, the presence of a blister was the only independent morphologic predictor of impending rupture (P = 0.001, Wald = 15).

CONCLUSION

In patients with small aneurysms, increased attention should be directed to the preoperative detection of blisters.