Factors affecting late survival after elective abdominal aortic aneurysm repair

Effects of abdominal aortic aneurysm on long-term survival in lung cancer patients

The major causes of death in patients with abdominal aortic aneurysm (AAA) are cardiovascular disease and cancer. The purpose of this study was to evaluate the effect of AAA on long-term survival in lung cancer patients. All patient data with degenerative type AAA and lung cancer over 50 years of age during the period 2009 to 2018 was collected retrospectively from a National Health Insurance Service (NHIS) administrative database and matched to lung cancer patients without AAA by age, sex, metastasis, and other comorbidities. Mortality rate was compared between the groups. A total of 956 AAA patients who could be matched with patients without AAA were included, and 3824 patients in the matched group were used for comparison. Patients with AAA showed higher risk of death compared with the matched cohort (adjusted hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.06-1.23, p < 0.001). When compared to a matched group of untreated AAA patients, patients with of history of AAA exhibited a significantly increased risk of overall mortality [HR (95%CI) 1.219 (1.113-1.335), p < .001, adjusted HR (95% CI) 1.177 (1.073-1.291), p = .001]. By contrast, mortality risk of AAA patients treated either by endovascular abdominal aortic repair or open surgical repair was not significantly different from that of the matched group (p = 0.079 and p = 0.625, respectively). The mortality risk was significantly higher when AAA was present in lung cancer patients, especially in patients with unrepaired AAA, suggesting the need for continuous cardiovascular risk management.

Extent of mural thrombus is not associated with increased 5-year mortality following elective AAA repair

BACKGROUND

Mural thrombus in abdominal aortic aneurysm (AAA) has been associated with increased rates of aneurysm growth as well as adverse cardiovascular events. The extent of mural thrombus in thoracoabdominal aortic aneurysms has recently been linked to 1-year mortality following endovascular repair and has been hypothesized as a marker for reduced cardiac reserve. This study investigates whether the extent of mural thrombus in infra-renal AAA is associated with 5-year mortality following elective repair.

METHODS

Retrospective review of all patients undergoing elective infra-renal AAA repair at a single academic medical center between 2007 and 2016 was performed. The following variables at the time of surgery were investigated for association with 5-year mortality: age, sex, ethnicity, insurance status and co-morbidities, repair type, renal insufficiency, end-stage renal disease on dialysis, history of smoking, coronary artery disease, congestive heart failure, diabetes mellitus, hypertension, stroke, chronic obstructive pulmonary disease, body mass index category, AAA diameter, and ratio of aortic thrombus to total aneurysm diameter.

RESULTS

Amongst 427 patients undergoing infra-renal AAA repair during the study period, 232 met extensive inclusion criteria. Univariate analysis found mean age (76 vs 72, p < 0.01), age cohort over 72 years (OR = 1.9, p = 0.04), renal insufficiency (OR = 3.1, p < 0.01), ESRD (OR = 6.5, p < 0.01), AAA diameter 6 cm or greater (OR = 2.3, p < 0.01), and mean AAA diameter (61.36 vs 56.99 mm, p < 0.01) all predictive of 5-year mortality. Multivariate analysis revealed renal insufficiency (p < 0.01) and AAA diameter 6 cm or greater (p = 0.03) to be significantly associated with 5-year mortality. The extent of mural thrombus was identical between 5-year survivors and non-survivors. The mean inner to outer AAA diameter was 0.65 in the survivor cohort and 0.64 in the mortality cohort. Inner to outer ratio of < 0.5 was identified in 23% of 5-year survivors and 27% of the mortality group.

CONCLUSIONS

In our experience, the extent of mural thrombus in AAA does not influence long-term survival after elective repair. AAA repair may provide protection against circulating components of mural thrombus which have the potential to promote atherosclerotic-related adverse events. Patients with renal insufficiency and larger AAA have increased risk of mortality 5 years after elective repair.

Systematic Review and Meta-analysis of Factors Influencing Survival Following Abdominal Aortic Aneurysm Repair

BACKGROUND

Predicting long-term survival following repair is essential to clinical decision making when offering abdominal aortic aneurysm (AAA) treatment. A systematic review and a meta-analysis of pre-operative non-modifiable prognostic risk factors influencing patient survival following elective open AAA repair (OAR) and endovascular aneurysm repair (EVAR) was performed.

METHODS

MEDLINE, Embase and Cochrane electronic databases were searched to identify all relevant articles reporting risk factors influencing long-term survival (≥1 year) following OAR and EVAR, published up to April 2015. Studies with <100 patients and those involving primarily ruptured AAA, complex repairs (supra celiac/renal clamp), and high risk patients were excluded. Primary risk factors were increasing age, sex, American Society of Anaesthesiologist (ASA) score, and comorbidities such as ischaemic heart disease (IHD), cardiac failure, hypertension, chronic obstructive pulmonary disease (COPD), renal impairment, cerebrovascular disease, peripheral vascular disease (PVD), and diabetes. Estimated risks were expressed as hazard ratio (HR).

RESULTS

A total of 5,749 study titles/abstracts were retrieved and 304 studies were thought to be relevant. The systematic review included 51 articles and the meta-analysis 45. End stage renal disease and COPD requiring supplementary oxygen had the worst long-term survival, HR 3.15 (95% CI 2.45-4.04) and HR 3.05 (95% CI 1.93-4.80) respectively. An increase in age was associated with HR of 1.05 (95% CI 1.04-1.06) for every one year increase and females had a worse survival than men HR 1.15 (95% CI 1.07-1.27). An increase in ASA score and the presence of IHD, cardiac failure, hypertension, COPD, renal impairment, cerebrovascular disease, PVD, and diabetes were also factors associated with poor long-term survival.

CONCLUSION

The result of this meta-analysis summarises and quantifies unmodifiable risk factors that influence late survival following AAA repair from the best available published evidence. The presence of these factors might assist in clinical decision making during discussion with patients regarding repair.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies

Background

Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time.

Methods

A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time.

Results

Five-year survival was 69% (95% CI 67 to 71%, I² = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969–2011 (log OR −0.001, 95% CI −0.014–0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR −0.058, 95% CI −0.095 to −0.021, I² = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR −0.118, 95% CI −0.142 to −0.094, I² = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042).

Conclusion

Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

β-Blockers improve outcomes in kidney disease patients having noncardiac vascular surgery

Beta-blockers are known to improve postoperative outcome after major vascular surgery. We studied the effects of beta-blockers in 2126 vascular surgery patients with and without kidney disease followed for 14 years. Creatinine clearance was calculated using the Cockcroft-Gault equation, and kidney function was categorized as Stage 1 for a reference group of 550 patients, Stage 2 with 808 patients, Stage 3 with 627 patients, and combined Stages 4 and 5 with 141 patients. Outcome measures were 30-day and long-term all-cause mortality with a mean follow-up of 6 years. Cox proportional hazards models were used to control cardiovascular risk factors, including propensity for beta-blocker use. In all, 129 (6%) and 1190 (56%) patients died respectively. Mortality rates were three- and two-fold higher, respectively, for patients at Stages 3-5 compared to the reference group for the two outcomes. beta-Blocker use was significantly associated with a lower risk of mortality after surgery. The overall adjusted hazard ratio was 0.35 and 0.62, respectively, for individuals at Stages 3-5 compared to the reference group for 30-day and long-term mortality. This study shows that kidney function is a predictor of all-cause mortality and beta-blocker use is associated with a lower risk of death in kidney disease patients undergoing elective vascular surgery.

Temporary worsening of renal function after aortic surgery is associated with higher long-term mortality

BACKGROUND

Little is known about acute changes in renal function in the postoperative period and the outcome of patients undergoing major vascular surgery. Specifically, data are scarce for patients in whom renal function temporarily decreases and returns to baseline at 3 days after surgery.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

1,324 patients who underwent elective open abdominal aortic aneurysm surgery in a single center.

PREDICTOR

Renal function (creatinine clearance was measured preoperatively and on days 1, 2, and 3 after surgery. Patients were divided into 3 groups: group 1, improved or unchanged (change in creatinine clearance, +/-10% of function compared with baseline); group 2, temporary worsening (worsening > 10% at day 1 or 2, then complete recovery within 10% of baseline at day 3); and group 3, persistent worsening (>10% decrease compared with baseline).

OUTCOMES & MEASUREMENTS

All-cause mortality.

RESULTS

30-day mortality rates were 1.3%, 5.0%, and 12.6% in groups 1 to 3, respectively. Adjusted for baseline characteristics and postoperative complications, 30-day mortality was the greatest in patients with persistent worsening of renal function (hazard ratio [HR], 7.3; 95% confidence interval [CI], 2.7 to 19.8), followed by those with temporary worsening (HR, 3.7; 95% CI, 1.4 to 9.9). During 6.0 +/- 3.4 years of follow-up, 348 patients (36.5%) died. Risk of late mortality was 1.7 (95% CI, 1.3 to 2.3) in the persistent-worsening group followed by those with temporary worsening (HR, 1.5; 95% CI, 1.2 to 1.4).

LIMITATIONS

No steady state was achieved to assess renal function.

CONCLUSION

Although renal function may recover completely after aortic surgery, temporary worsening of renal function was associated with greater long-term mortality.

Impact of disseminated tumor cells in gastrointestinal cancer

The detection of epithelial cells by sensitive immunological and molecular methods in blood, lymph nodes or bone marrow of gastrointestinal cancer patients may open a new approach to clinical metastasis research. The phenotypic and genomic characterization of these cells is of great value in the prediction of the further course of the disease and the monitoring of response to treatment. In addition, the role of ultrastaging in blood, lymph nodes and bone marrow of cancer patients for the indication of multimodal therapy is discussed in this review. The impact of prognostic or predictive factors for new treatment protocols in patients with gastrointestinal cancer was evaluated as well as the correlation with clinical factors.

Indications for operative management of abdominal aortic aneurysms

The increasing incidence of abdominal aortic aneurysms, along with the more frequent use of screening techniques, has resulted in greater numbers of patients with small abdominal aortic aneurysms. The questions of frequency of surveillance and timing of intervention are the two most controversial issues faced by surgeons dealing with this condition. Most management decisions are based on the size of the aneurysm but other factors must also be considered. This review makes recommendations on the management of small abdominal aortic aneurysms according to the current available evidence.

Carotid ultrasound findings as a predictor of long-term survival after abdominal aortic aneurysm repair: a 14-year prospective study

PURPOSE

Several factors have been related to long-term survival after open abdominal aortic aneurysm (AAA) repair. The effect of carotid stenosis on outcome has not yet been examined. We performed an open prospective study to evaluate the prognostic significance of carotid stenosis on long-term survival of patients who had undergone elective operative repair of AAA.

METHODS

Two hundred eight patients who underwent elective open AAA repair in our department between March 1987 and December 2001 were included in the study. All patients were evaluated preoperatively with color duplex ultrasound (US) scanning of the carotid arteries, and were followed up with clinical examination and carotid duplex US scanning 1 month after the operation and every 6 months thereafter. Median duration of follow-up was 50 months (range, 5-181 months). Cardiovascular morbidity and mortality, as well as all causes of mortality, were recorded and analyzed with regard to traditional risk factors and carotid US findings.

RESULTS

Twenty-seven fatal and 46 nonfatal cardiovascular events were recorded. Both univariate and multivariate analysis showed that carotid stenosis 50% or greater and echolucent plaque were significantly associated with cardiovascular mortality and morbidity. Carotid stenosis was a stronger predictor of cardiovascular death than was ankle/brachial index. Age, hypercholesterolemia, coronary artery disease, and diabetes mellitus were also associated with higher mortality and morbidity from cardiovascular causes.

CONCLUSION

Patients electively operated on for AAA repair and with stenosis 50% or greater and echolucent plaque at duplex US scanning are at significantly increased risk for cardiovascular mortality and morbidity. Carotid US can therefore be used to select a subgroup of patients with AAA who might benefit from medical intervention, including antiplatelet and lipid-lowering agents.

Cardiac risk stratification in patients undergoing endoluminal graft repair of abdominal aortic aneurysm: a single-institution experience with 365 patients

OBJECTIVE

Patients undergoing abdominal aortic aneurysm repair have a high incidence of coexisting cardiac disease. The traditional cardiac risk stratification for open abdominal aortic aneurysm surgery may not apply to patients undergoing endoluminal graft exclusion. The purpose of this study was to examine predictive risk factors for perioperative cardiac events.

METHODS

As part of multiple prospective endograft trials approved by the US Food and Drug Administration, data for 365 patients who underwent endoluminal graft repair from 1996 to 2001 were collected. Variables included for analysis were age and sex; history of smoking; presence of hypertension, diabetes mellitus, or renal insufficiency; Eagle clinical cardiac risk factors; American Society of Anesthesiologists index; type of anesthesia administered; estimated blood loss; preoperative hemoglobin level; preoperative use of beta-blocker therapy; duration of surgery; need for iliac artery conduit; and concomitant other vascular procedures. Univariate and multivariate logistic regression analysis were used to determine which variables were predictive of an adverse perioperative cardiac event, eg, Q wave and non-Q wave myocardial infarction (MI), congestive heart failure (CHF), severe arrhythmia, and unstable angina.

RESULTS

The study cohort included 322 men and 43 women (mean age, 74.2 years). Fifty-two (14.2%) postoperative cardiac events occurred: severe dysrhythmia in 15 patients (4.1%), MI in 14 patients (3.8%), non-Q wave MI in 8 patients (2.2%), CHF in 8 patients (2.2%), and unstable angina in 7 patients (1.9%). Univariate analysis demonstrated that age 70 years or older (P =.034), history of MI (P =.018), angina (P =.004), history of CHF (P <.001), two or more Eagle risk factors (P <.001), and lack of use of preoperative beta-blocker therapy (P =.005) were predictors of perioperative cardiac events. Multivariate analysis identified only age 70 years or older (P =.026), history of MI (P =.024) or CHF (P =.001), and lack of use of preoperative beta-blocker therapy (P =.007) as independent risk factors for an adverse cardiac event.

CONCLUSIONS

Age 70 years or older, history of MI or CHF, and lack of use of preoperative beta-blocker therapy are independent risk factors for perioperative cardiac events in patients undergoing endoluminal graft repair.

Transrenal fixation of endovascular stent-grafts for infrarenal aortic aneurysm repair: mid-term results

PURPOSE

We evaluated mid-term results of a single-center consecutive series of endovascular stent-grafts implanted for aortic aneurysm repair with transrenal fixation, to determine clinical outcome, aneurysm anatomy, renal artery patency, and renal complications.

METHODS

Modular stent-grafts were placed with transrenal fixation in 37 patients between November 1998 and July 2000. Follow-up evaluation included clinical examination, laboratory evaluation of serum creatine concentration, computed tomographic angiography, and renal duplex scanning.

RESULTS

Thirty-seven patients underwent transrenal fixation of aortic stent-grafts as part of a Phase II US Food and Drug Administration study. Two patients subsequently underwent follow-up at institutions closer to their homes, and thus provided clinical information but no long-term renal or aneurysm morphologic data. There were no perioperative deaths. Five patients died during follow-up, at a mean of 9 months, because of myocardial infarction in 4 patients and respiratory failure in 1 patient. Thirty patients, ages 75 +/- 8 years, have been followed up for 28.5 +/- 7.2 months. Aneurysm diameter at follow-up was 5.0 +/- 0.8 cm, compared with 5.7 +/- 0.8 cm preoperatively. In 5 patients, endoleak developed during follow-up: 1 type I leak was treated with an aortic cuff, with temporary stabilization of the aneurysm and correction of the endoleak; 2 type II endoleaks were treated with translumbar coil embolization, and 1 resolved spontaneously; and 1 type III endoleak was treated with a combination of coil embolization and stent-graft extension to cover a graft defect. Preoperatively, serum creatinine concentration was normal in 23 patients, but increased persistently in 2 patients and was abnormal in 7 patients. Postoperatively, creatine concentration increased in 4 patients to greater than 20% of baseline level. Seventeen patients had no evidence of renal artery stenosis, compared with 13 patients with renal artery stenosis. Of 41 normal renal arteries, 90% remained unchanged, 1 became occluded, 3 demonstrated 60% stenosis. Nephrectomy was necessary in 1 patient because of cancer. Of 19 abnormal renal arteries, progression of disease was noted in 3 arteries.

CONCLUSIONS

Transrenal fixation of aortic stent-grafts can be performed with acceptable mid-term outcome with respect to mortality, need for follow-up intervention, and aneurysm exclusion with protection from rupture. Postprocedural stenosis can develop in both normal and abnormal renal arteries. Rate of progression of disease was greater in patients with preprocedural renal dysfunction compared with patients with normal renal arteries. This is merely an observation, and may not be related to transrenal fixation. Long-term follow up is needed.

Combined infrarenal aorta and carotid artery reconstruction: early and late outcome in 152 patients

Between January 1, 1985 and December 31, 1998, we performed combined infrarenal aorta and carotid artery reconstruction in 152 consecutive patients. The mean age of these patients was 65.4 +/- 8.6 years (range, 43-88 years). Infrarenal aortic disease involved abdominal aortic aneurysm in 78 patients (44.7%) and occlusive aortoiliac lesions in 84 (55.3%). Carotid artery disease was detected by performing routine Doppler ultrasonography prior to aortic reconstruction. A total of 121 carotid lesions were asymptomatic (79.6%). A total of 32 patients (21%) had a history of contralateral carotid repair. Eighty-one patients (53.2%) presented with coronary artery disease diagnosed on the basis of clinical and/or laboratory testing. Concurrent lesions were diagnosed in the renal arteries of 43 patients (28.3%) and in the visceral arteries of 16 (10.5%). Based on the results of cardiac evaluation, eight patients underwent coronary revascularization before combined reconstruction. Renal or visceral artery reconstruction was carried out during the same procedure in 30 (19.7%) and 10 (6.6%) patients, respectively. Univariate analysis demonstrated six factors that were significantly associated with perioperative mortality and morbidity: age, coronary artery disease, chronic obstructive pulmonary disease, procedure time, intraoperative blood loss, and creatinemia over 140 micromol/L. Multivariate analysis showed that only the first four of these factors were independent. Actuarial survival in the overall population, including the patients who died during the perioperative period, was 73.9 +/- 7.1% at 5 years and 50.9 +/- 10% at 10 years. From our experience, we conclude that combined infrarenal aorta and carotid artery reconstruction can be performed with no additional operative risks and consequently is the strategy of choice. In our series neither procedure had any effect on the early or late outcome of the other. Our experience suggests that combined surgery is a safe alternative to staged surgery in patients with concurrent lesions involving the infrarenal aorta and carotid artery bifurcation.

Risk factors and operative results of patients aged less than 66 years operated on for asymptomatic abdominal aortic aneurysm

OBJECTIVE

To report risk factors, early operative results and survival after repair of asymptomatic abdominal aortic aneurysm (AAA) in patients aged less than 66 years.

DESIGN

a retrospective study based on a prospectively updated database in a University hospital.

PATIENTS AND METHODS

Between 1985 and 1999, 118 patients of less than 66 years were operated for AAA. Pre-operative risk factors, early complications, operative mortality (<30 days), and survival are compared with that of 333 older patients operated during the same period.

RESULTS

Risk factors were similar to older patients. Serious early (<30 days) complications were recorded in 20% of both groups. The operative mortality was 1.7% for the younger patients and 6% for the older (n.s.). The eight-year survival of the younger patients was 69%, which was significantly below that of a demographically matched population. The older patients had a significantly poorer eight-year survival of 47% (p<0.01), but their relative survival was significantly better (p<0.05).

CONCLUSIONS

Younger patients with an AAA were not healthier than older patients. Complications were equally common among both groups. Although the operative mortality was lower, the long-term relative survival was poorer than that of the older patient. Present data do not support a more aggressive surgical attitude towards the younger patients with an asymptomatic abdominal aortic aneurysm, as compared to the older.

Aortic aneurysm diameter and risk of cardiovascular mortality

After successful surgical repair of an abdominal aortic aneurysm, patients have for many years an increased risk of death from cardiovascular causes. We have tested the hypothesis that for patients with abdominal aortic aneurysms, the risk of nonaneurysm cardiovascular mortality before and after surgery increased with aneurysm diameter. Records of aneurysm repair or rupture and mortality were available from 2305 patients entered into the UK Small Aneurysm Trial and Study. Two hundred fifty-nine deaths occurred before aneurysm repair or rupture (mean follow-up 1.7 years), and 325 occurred after surgical repair (mean follow-up 3.6 years). The risk of nonaneurysm-related mortality and cardiovascular death before and after surgery increased with aneurysm diameter at baseline, even after adjustment for other known risk factors. The adjusted hazard ratios for cardiovascular mortality, per standard deviation (0.8-cm) increase in aneurysm diameter, were 1.34 (95% CI 1.01 to 1.79) and 1.31 (95% CI 1.06 to 1.63) in the periods before aneurysm repair or rupture and after aneurysm repair, respectively. The significant association between aortic diameter and cardiovascular mortality, excluding aneurysm-related deaths, suggests that aneurysm diameter is an independent marker of cardiovascular disease risk.

Long-term relative survival following surgery for abdominal aortic aneurysm: a review

BACKGROUND

The literature reporting the long-term survival following surgery for abdominal aortic aneurysm (AAA) tends to be confusing. As a result, many clinicians looking after patients with AAA may be uncertain about the five-year survival of a given patient. This is in marked contrast to the situation for patients with malignant disease. With the current interest in population screening and endoluminal stenting for AAA, an understanding of long-term survival is increasingly important.

METHODS

Thirty two publications in the English language over the last 20 years, containing data pertaining to five-year survival following routine elective surgery for AAA in unselected patients, were identified using Medline searches.

RESULTS AND CONCLUSIONS

A range of important methodological differences were noted. The mean five-year crude survival was about 70% while the expected survival of a matched population was close to 80%. Survival was further reduced by about 10% in cases with significant coronary heart disease. Age alone is not a predictor of long-term relative survival with octogenarians who survive beyond 30 days surviving longer than an age-matched population.