Current Outcome of Elective Open Repair for Infrarenal Abdominal Aortic Aneurysm

Status of diagnosis and therapy of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) are characterized by localized dilation of the abdominal aorta. They are associated with several serious consequences, including compression of adjacent abdominal organs, pain, treatment-related financial expenditure. The main complication of AAA is aortic rupture, which is responsible for about 200,000 deaths per year worldwide. An increasing number of researchers are dedicating their efforts to study AAA, resulting in significant progress in this field. Despite the commendable progress made thus far, there remains a lack of established methods to effectively decelerate the dilation of aneurysms. Therefore, further studies are imperative to expand our understanding and enhance our knowledge concerning AAAs. Although numerous factors are known to be associated with the occurrence and progression of AAA, the exact pathway of development remains unclear. While asymptomatic at most times, AAA features a highly unpredictable disease course, which could culminate in the highly deadly rupture of the aneurysmal aorta. Current guidelines recommend watchful waiting and lifestyle adjustment for smaller, slow-growing aneurysms, while elective/prophylactic surgical repairs including open repair and endovascular aneurysm repair are recommended for larger aneurysms that have grown beyond certain thresholds (55 mm for males and 50 mm for females). The latter is a minimally invasive procedure and is widely believed to be suited for patients with a poor general condition. However, several concerns have recently been raised regarding the postoperative complications and possible loss of associated survival benefits on it. In this review, we aimed to highlight the current status of diagnosis and treatment of AAA by an in-depth analysis of the findings from literatures.

Coexistence and management of abdominal aortic aneurysm and coronary artery disease

BACKGROUND

Abdominal aortic aneurysm (AAA) and coronary atherosclerosis share common risk factors. In this study, a single-center management experience of patients with a coexistence of AAA and coronary artery disease (CAD) is presented.

METHODS

271 consecutive patients who underwent elective AAA repair were reviewed. Coronary imaging in 118 patients was considered suitable for exploration of AAA coexistence with CAD.

RESULTS

Significant coronary stenosis (> 70%) were found in 65.3% of patients. History of cardiac revascularization was present in 26.3% of patients, myocardial infarction (MI) in 31.4%, and 39.8% had both. In a subgroup analysis, prior history of percutaneous coronary intervention (PCI) (OR = 6.9, 95% CI 2.6-18.2, p < 0.001) and patients' age (OR = 1.1, 95% CI 1.0-1.2, p = 0.007) were independent predictors of significant coronary stenosis. Only 52.0% (40/77) of patients with significant coronary stenosis underwent immediate coronary revascularization prior to aneurysm repair: PCI in 32 cases (4 drug-eluting stents and 27 bare metal stents), coronary artery bypass graft in 8 cases. Patients undergoing revascularization prior to surgery had longer mean time from coronary imaging to AAA repair (123.6 vs. 58.1 days, p < 0.001). Patients undergoing coronary artery evaluation prior to AAA repair had shorter median hospitalization (7 [2-70] vs. 7 [3-181] days, p = 0.007) and intensive care unit stay (1 [0-9] vs. 1 [0-70] days, p = 0.014) and also had a lower rate of major adverse cardiovascular events or multiple organ failure (0% vs. 3.9%, p = 0.035). A total of 11.0% of patients had coronary artery aneurysms.

CONCLUSIONS

Patients with AAA might benefit from an early coronary artery evaluation strategy.

Frequency of concomitant ischemic heart disease and risk factor analysis for an early postoperative myocardial infarction after elective abdominal aortic aneurysm repair

Purpose

We aimed to see the frequency of concomitant ischemic heart disease (IHD) in Korean patients with abdominal aortic aneurysm (AAA) and to determine risk factors for an early postoperative acute myocardial infarction (PAMI) after elective open or endovascular AAA repair.

Methods

We retrospectively reviewed a database of patients who underwent elective AAA repair over the past 11 years. Patients were classified into 3 groups: control group; group I, medical IHD treatment; group II, invasive IHD treatment. Rates of PAMI and mortality at 30 days were compiled and compared between groups according to the type of AAA repair.

Results

Six hundred two elective repairs of infrarenal or juxtarenal AAAs were enrolled in this study. The patients were classified into control group (n = 398, 66.1%), group I (n = 73, 12.1%) and group II (n = 131, 21.8%). PAMI developed more frequently after open surgical repair (OSR) than after endovascular aneurysm repair (EVAR) (5.4% vs. 1.3%, P = 0.012). In OSR patients (n = 373), PAMI developed 2.1% in control group, 18.0% in group I and 7.1% in group II (P < 0.001). In EVAR group (n = 229), PAMI developed 0.6% in control group, 4.3% in group I and 2.2% in group II (P = 0.211). On the multivariable analysis of risk factors of PAMI, PAMI developed more frequently in patients with positive functional stress test.

Conclusion

The prevalence of concomitant IHD was 34% in Korean AAA patients. The risk of PAMI was significantly higher after OSR compared to EVAR and in patients with IHD compared to control group. Though we found some risk factors for PAMI, these were not applied to postoperative mortality rate.

A systematic review and meta-analysis indicates underreporting of renal dysfunction following endovascular aneurysm repair

Deterioration in renal function has been described after endovascular repair of abdominal aortic aneurysms (EVRs). The etiology is multifactorial and represents an important therapeutic target. A need exists to quantitatively summarize incidence and severity of renal dysfunction after EVR to allow better-informed attempts to preserve renal function and improve life expectancy. Here a systematic search was performed using Medline and Embase for renal function after EVR applying PRISMA statements. Univariate and multivariate random-effects meta-analyses were performed to estimate pooled postoperative changes in serum creatinine and creatinine clearance at four time points after EVR. Clinically relevant deterioration in renal function was also estimated at 1 year or more after EVR. Pooled probability of clinically relevant deterioration in renal function at 1 year or more was 18% (95% confidence interval of 14-23%, I2 of 82.5%). Serum creatinine increased after EVR by 0.05 mg/dl at 30 days/1 month, 0.09 mg/dl at 1 month to 1 year, and 0.11 mg/dl at 1 year or more (all significant). Creatinine clearance decreased after EVR by 5.65 ml/min at 1 month-1 year and by 6.58 ml/min at 1 year or more (both significant). Thus, renal dysfunction after EVR is common and merits attention.

Endovascular aneurysm repair: a perioperative perspective

Endovascular aneurysm repair (EVAR), has surpassed open repair as the technique of choice in many centres in response to several large studies which showed significantly improved 30-day mortality. While several multicentre EVAR trials looked at surgical outcomes, very few have specifically investigated the effect of anaesthetic techniques or perioperative care of these patients. The purpose of this review to is to present some of the current evidence for the different aspects of perioperative management of patients undergoing EVAR. This includes surgical considerations, pre-operative assessment, and choice of anaesthetic technique as well as pharmacological protective strategies.

Outcome in cirrhotic patients after elective surgical repair of infrarenal aortic aneurysm

OBJECTIVE

Abdominal surgery in patients with advanced liver disease has been reported to be associated with high morbidity and mortality rates. However, the surgical risk of infrarenal abdominal aortic aneurysm (AAA) repair in cirrhotics remains ill-defined. We reviewed our experience to investigate the predictors of the outcome in cirrhotic patients after elective AAA open repair.

METHODS

Between January 2001 and March 2006, 1189 patients underwent elective open repair of infrarenal AAA and 24 (2%) had a biopsy-proven cirrhosis (23 male, 1 female; mean age, 68 ± 7 years). The latter were retrospectively stratified according to the Child-Turcotte-Pugh (CTP) score and the Model for End-Stage Liver Disease (MELD) score. Operative variables, perioperative complications, and survival were recorded and compared with those of 48 concurrent noncirrhotic controls matched (2:1) by gender, age, aneurysm size, preoperative glomerular filtration rate, and type of reconstruction. The effect of CTP and MELD scores on midterm survival was investigated in cirrhotics with the Kaplan-Meier log-rank method.

RESULTS

No intraoperative or 30-day deaths were recorded. No significant differences in terms of major perioperative complications were observed between cirrhotic patients and controls. Operative time and intraoperative blood transfusion requirement were significantly higher in cirrhotics (162 ± 49 vs 132 ± 39 minutes; P = .007 and 273 ± 364 vs 84 ± 183 mL; P = .040, respectively). Hospital length of stay was nearly doubled in cirrhotic patients (11.0 ± 2.8 vs 5.8 ± 1.5 days; P < .0001). Twenty-two cirrhotic patients were classified as CTP A and two as CTP B. Median MELD score was 8 (range, 6-14). CTP class B was associated with higher intraoperative blood transfusion requirement (941 ± 54 vs 213 ± 314 mL; P = .029). At a mean follow-up of 30.7 ± 22.1 months, five deaths were recorded in cirrhotics, and three in controls. Actuarial survival at 2 years was 77.4% in cirrhotics and 97.8% in controls (log-rank test, P = .026). Both CTP B patients died within 6 months. CTP class B and a MELD score ≥10 were associated with reduced midterm survival rates (log-rank test, P < .0001 and P = .021, respectively).

CONCLUSIONS

In our experience, elective AAA open repair in relatively compensated cirrhotics was safely performed with an acceptable increase of the magnitude of the operation. However, the reduced life expectancy of cirrhotics with a MELD score ≥10 suggests that such a procedure may not be warranted in this subgroup of patients.

AAA stent-grafts: past problems and future prospects

Endovascular aneurysm repair (EVAR) has quickly gained popularity for infrarenal abdominal aortic aneurysm repair during the last two decades. The improvement of available EVAR devices is critical for the advancement of patient care in vascular surgery. Problems are still associated with the grafts, many of which can necessitate the conversion of the patient to open repair, or even result in rupture of the aneurysm. This review attempts to address these problems, by highlighting why they occur and what the failings of the currently available stent grafts are, respectively. In addition, the review gives critical appraisal as to the novel methods required for dealing with these problems and identifies the new generation of stent grafts that are being or need to be designed and constructed in order to overcome the issues that are associated with the existing first- and second-generation devices.

Management of coronary artery disease in patients undergoing elective abdominal aortic aneurysm open repair

BACKGROUND

The efficacy of prophylactic coronary revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery in patients with abdominal aortic aneurysm (AAA) scheduled for open repair surgery remains controversial.

HYPOTHESIS

Concomitant coronary artery disease (CAD) with no inducible ischemia can be medically treated in AAA patients undergoing open repair as long as the existence of CAD is recognized.

METHOD

A retrospective analysis of acute and long-term outcomes was performed for 122 patients with AAA who underwent coronary arteriography (CAG) for preoperative evaluation followed by elective open repair.

RESULTS

Preoperative CAG revealed no CAD in 54 patients (non-CAD group) and the existence of CAD in 68 patients. Prophylactic PCI or CABG surgery was performed in 16 patients (CAD-PCI/CABG group) with symptomatic angina, ischemia proven by pharmacological stress scintigraphy, or coexistence of reduced cardiac contraction and coronary stenosis in multiple vessels. Medical treatment was administered to 52 patients who had no signs of ischemia (CAD-medical group). During the perioperative period, no cardiac event occurred irrespective of the existence of CAD. The long-term outcomes in the CAD-medical group were equivalent to those in the non-CAD group. In the CAD-PCI/CABG group, the cardiac event-free rate was comparable with that of other groups, although mortality was higher.

CONCLUSION

In patients undergoing AAA open repair, medical treatment for concomitant CAD with no obvious inducible ischemia does not confer unfavorable outcomes. Although prophylactic coronary revascularization possibly prevents future cardiac events, it appears to be necessary in a very limited number of cases.

Effects of human atrial natriuretic peptide on renal function in patients undergoing abdominal aortic aneurysm repair

OBJECTIVE

Ischemia-reperfusion injury is an important cause of renal dysfunction after abdominal aortic aneurysm repair. Human atrial natriuretic peptide (hANP) is a potent endogenous natriuretic, diuretic, and vasorelaxant peptide. The objective of the present study was to evaluate the effects of hANP on renal function in patients undergoing abdominal aortic aneurysm repair.

DESIGN

A prospective, randomized, placebo-controlled study

SETTING

Intensive care unit of a university hospital.

PATIENTS

Forty patients undergoing elective abdominal aortic aneurysm repair.

INTERVENTIONS

The patients were randomized to receive a continuous infusion of either hANP (0.01-0.05 microg/kg/min) (n = 20) or placebo (n = 20) immediately before aortic cross-clamping. The infusion of hANP or placebo continued for 48 hrs.

MEASUREMENTS AND MAIN RESULTS

Blood and urine samples were taken before surgery, at admission to the intensive care unit, and on days 1, 2, and 3 postoperatively, for measurement of serum concentrations of sodium, creatinine, and blood urea nitrogen and plasma concentrations of ANP and brain natriuretic peptide (BNP). Urine volume and urinary concentrations of N-acetyl-beta-D-glucosaminidase (NAG), sodium, and creatinine were also measured. The mean plasma concentration of ANP was significantly higher in the hANP group than in the placebo group. The mean plasma BNP concentration was significantly lower in the hANP group than in the placebo group. The mean serum concentrations of creatinine and blood urea nitrogen were significantly (p < .05) lower in the hANP group than in the placebo group. The mean urine volume and mean creatinine clearance were significantly (p < .05) higher in the hANP group than in the placebo group. The mean urinary NAG/creatinine ratio was significantly (p < .05) lower in the hANP group than in the placebo group.

CONCLUSIONS

The intraoperative and postoperative infusion of low-dose hANP preserved renal function in patients undergoing abdominal aortic aneurysm repair. Further studies are needed to assess the efficacy of prophylactic hANP infusion on perioperative renal outcome.

Chronic Renal Insufficiency and Risk of Early Mortality in Patients Undergoing Carotid Endarterectomy

We compared early outcome after carotid endarterectomy (CEA) in patients (n = 857 with 1,011 CEA interventions) with and without chronic renal insufficiency (CRI). Two groups were compared: a group with normal renal function (n = 909) and a group with CRI (creatinine >/=1.5 mg/dL and clearance of </=30 mL/min, as well as dialysis and transplant patients, n = 102). Mean age was significantly higher in CRI patients (71.22 vs. 68.33 years, p = 0.001). The incidence of smokers was 53.9% in the non-CRI group vs. 39.2% in CRI patients (p = 0.005). Hypertension (88.2% vs. 75.1, p = 0.003) and cardiac disease (58.8% vs. 47.4%, p = 0.029) were more common in the CRI group. The perioperative mortality rate was significantly higher in CRI patients (3.9% vs. 1.0%, p = 0.013). Multivariate logistic regression analysis showed a significant association between CRI and 30-day death rate (odds ratio = 3.76, p = 0.032). In this series, CRI patients presented an increased mortality. The mortality risk may be related to the increased rates of preoperative hypertension and coronary disease and perioperative myocardial infarction. A more reserved attitude seems indicated in planning CEA for patients with renal dysfunction in combination with a history of coronary artery disease.

Glomerular filtration rate is a predictor of mortality after endovascular abdominal aortic aneurysm repair

OBJECTIVE

Clinically evident renal disease is a risk factor for mortality after aneurysm repair. Serum creatinine is widely used as a measure of renal function in the preoperative evaluation of patients. Unfortunately, serum creatinine concentration is influenced by muscle mass, hydration status, and glomerular filtration rate (GFR). Calculated GFR, which takes predictors of muscle mass such as age, gender, and weight into account, is a more sensitive determinant of renal function than serum creatinine. We hypothesized that GFR would more accurately predict mortality after EVAR than serum creatinine.

METHODS

We retrospectively evaluated our database of 398 patients who underwent EVAR with the AneuRx device between October 1999 and October 2004. There were 340 men and 58 women with a mean age of 73. GFR was calculated using the Cockcroft-Gault equation. The patients were divided into four quartiles by preoperative GFR: I (7 to 45), II (45 to 60), III (61 to 79), and IV (> or =80). Survival was estimated with the Kaplan-Meier method, and heterogeneity of mortality across strata was evaluated using the log-rank test. The GFR quartiles were compared with clinically accepted criteria for abnormal renal function (serum creatinine level > or =1.7).

RESULTS

Actuarial survival at 48 months was 61.5%, 70.5%, 86.0%, and 85.7% for GFR quartiles I to IV, respectively (P < .003). Thirty-day mortality was 2.2% in quartile I, 3.2% in quartile II, and 0 in quartiles III and IV (P = .03 for q1 + q2 vs q3 + q4, P < .02 for q2 vs q3 + q4). Survival curves for quartiles II to IV were statistically indistinguishable, with quartile II running tangential to the two higher quartiles after the perioperative period. Quartile I fared significantly worse than the other three quartiles for the entire follow-up period (P < .005). According to American Kidney Foundation criteria (GFR <90), 83.3% of patients had abnormal renal function compared with 16.1% with abnormal serum creatinine (>1.7) (P < .0002).

CONCLUSION

The risk of perioperative and long-term mortality in patients undergoing EVAR is more accurately stratified by using calculated GFR than serum creatinine alone. A GFR <45 is associated with decreased survival after EVAR. Perioperative mortality at a GFR of 45 to 60 is comparable with that of the lower quartile (GFR <45), but late survival is comparable with that of patients with GFR >60. The finding of increased risk of early mortality in patients in the 45 to 60 GFR range, with survivors enjoying good long-term outcome, suggests that these patients may most benefit from the use of alternative contrast agents and periprocedural renal protection techniques.

Abdominal aortic aneurysm

Abdominal aortic aneurysms cause 1.3% of all deaths among men aged 65-85 years in developed countries. These aneurysms are typically asymptomatic until the catastrophic event of rupture. Repair of large or symptomatic aneurysms by open surgery or endovascular repair is recommended, whereas repair of small abdominal aortic aneurysms does not provide a significant benefit. Abdominal aortic aneurysm is linked to the degradation of the elastic media of the atheromatous aorta. An inflammatory cell infiltrate, neovascularisation, and production and activation of various proteases and cytokines contribute to the development of this disorder, although the underlying mechanisms are unknown. In this Seminar, we aim to provide an updated review of the pathophysiology, current and new diagnostic procedures, assessment, and treatment of abdominal aortic aneurysm to provide family practitioners with a working knowledge of this disorder.