In-hospital mortality from abdominal aortic surgery in Great Britain and Ireland: Vascular Anaesthesia Society audit

Contemporary Management of Abdominal Aortic Aneurysms

PURPOSE OF REVIEW

Abdominal aortic aneurysms (AAA) can carry extremely high mortality rates and most will only present with symptoms with impending rupture. We present an overview of management of this disease process starting with screening, to medical management, surveillance and treatment options currently available, as well as those being studied for future use.

RECENT FINDINGS

Screening has been proven to reduce the mortality rate. There still remains a paucity of data to support medical therapies to help mitigate the rate of aneurysm growth and prevent rupture. However, on the topic of repair, there have been advancements in endovascular devices which have broadened the scope of treatment for patients with anatomy not amenable to standard endovascular repair or those who are not suitable candidates for open surgical repair. Appropriate surveillance, risk factor modification, and operative repair, when indicated, are the cornerstones of contemporary management of AAAs. Advancements in endovascular technologies have allowed us to treat more patients. Further research is warranted on non-operative medical therapies.

The impact of combined iliac occlusive disease and aortic aneurysm on open surgical repair

OBJECTIVE

Severe aortoiliac occlusive disease is a relative contraindication for endovascular aneurysm repair, owing to an association with high stent graft-related complication and reintervention rates in this population. Open AAA repair requiring aortofemoral bypass (AFB), however, may represent a unique population with differing outcomes from standard open repair. We sought to compare the demographic and procedural characteristics, as well as outcomes of patients undergoing standard intra-abdominal repairs (STD) versus those requiring AFB.

METHODS

Using a prospectively maintained database, we retrospectively identified patients who underwent open AAA repair from 1994 to 2017. A total of 1087 consecutive cases were performed consisting of 981 STD (681 tube graft, 300 aortoiliac) and 106 AFB cases. Demographics, procedural data, postoperative complications, and long-term survival were analyzed.

RESULTS

The AFB cohort had more women (39.0 vs 22.8%; P = .001) and higher rates of hypertension (81.1 vs 69.8%; P = .015), chronic obstructive pulmonary disease (28.3 vs 17.4%; P = .006), and smoking (50.9 vs 36%; P = .002). The AFB group had smaller mean aortic (5.22 vs 5.77 cm; P = .001) and graft (17.08 vs 18.2 mm; P = .001) diameters. Proximal clamp position and blood loss were equivalent, although total anesthesia time was longer (295 vs 234 minutes; P = .001) in the AFB cohort. Overall 30-day postoperative morbidity (38.7 vs 24.8%; P = .002) was higher in the AFB group. Specifically, postoperative renal insufficiency (8.2 vs 3.4%; P = .032), wound infection (5.7 vs 1.2%; P = .005), and hematoma/seroma (5.7 vs 1.2%; P = .003) were more likely. Hospital length of stay was longer for AFB (11.9 vs 9.9 days; P = .007). The 30-day mortality (0.9% AFB vs 1.8% STD; P = .50) and major morbidity (17 vs 11.5%; P = .10) did not differ. Reintervention rate within 30 days of the initial surgery (12.3 vs 4.6; P = .001) and overall (33 vs 18.9%; P = .001) was higher in the AFB group. Long-term survival was lower in the AFB group (5-year survival: 63.1% AFB vs 71.9% STD; hazard ratio 0.76, log-rank P = .047). Multivariate regression analysis identified age, comorbid conditions, and aneurysm characteristics-rather than repair type-as independent predictors of 30-day reintervention and mortality at 5 years.

CONCLUSIONS

Patients requiring AFB for AAA owing to associated iliac occlusive disease have more preoperative comorbidities, postoperative complications, a longer length of stay, reintervention rates and shorter 5-year survival. Patient and aneurysm characteristics rather than surgical repair type appear to be responsible for these differences. Nevertheless, 30-day mortality and major morbidity were comparable, making AFB an attractive alternative to endovascular aneurysm repair in patients with advanced iliac occlusive disease.

Using machine learning methods for predicting inhospital mortality in patients undergoing open repair of abdominal aortic aneurysm

An abdominal aortic aneurysm is an abnormal dilatation of the aortic vessel at abdominal level. This disease presents high rate of mortality and complications causing a decrease in the quality of life and increasing the cost of treatment. To estimate the mortality risk of patients undergoing surgery is complex due to the variables associated. The use of clinical decision support systems based on machine learning could help medical staff to improve the results of surgery and get a better understanding of the disease. In this work, the authors present a predictive system of inhospital mortality in patients who were undergoing to open repair of abdominal aortic aneurysm. Different methods as multilayer perceptron, radial basis function and Bayesian networks are used. Results are measured in terms of accuracy, sensitivity and specificity of the classifiers, achieving an accuracy higher than 95%. The developing of a system based on the algorithms tested can be useful for medical staff in order to make a better planning of care and reducing undesirable surgery results and the cost of the post-surgical treatments.

Does Specialization Improve Outcome in Abdominal Aortic Aneurysm Surgery?

Specialization and high volume are reported to be related to a better outcome after abdominal aortic aneurysm repair. The aim of this study was to compare, in patients undergoing abdominal aortic aneurysm repair, the outcomes of those whose surgery was done by general surgeons with the outcomes of those whose surgery was done by specialist vascular surgeons.

All patients undergoing abdominal aortic aneurysm repair at the Basel University Hospital (referral center) from January 1990 to December 2000 were included. Patients with endovascular treatment were excluded.

Operations in group A ( n = 189), between January 1990 and May 1995, were done by general surgeons. Operations in group B ( n = 291), between June 1995 and December 2000, were done by vascular surgeons.

In-hospital mortality and local and systemic complications were assessed.

In-hospital mortality rates were significantly lower for group B (with specialist surgeons) than for group A, both overall (group B, 11.7%; group A, 21.7%; p = .003) and for emergency interventions (group B, 28.1%; group A, 41.9%; p = .042). The reduction in mortality for elective surgery in group B was not statistically significant (group B, 1.1%; group A, 4.9%; p = .054). There were significantly fewer pulmonary complications in group B compared with group A ( p = .000).

We conclude that in patients undergoing abdominal aortic aneurysm repair, those whose surgery is done by a specialized team have a significantly better outcome than those whose surgery is done by general surgeons.

Impact of coexisting aneurysms on open revascularization for aortoiliac occlusive disease

OBJECTIVE

National data evaluating outcomes for occlusive abdominal aortic reconstructions are well described. The relative effect of operative indication as well as the presence of concomitant abdominal aortic aneurysm (AAA) on in-hospital mortality is not well defined.

METHODS

The Nationwide Inpatient Sample was queried to identify patients who underwent open aortic surgery (2003-2010). Indication for surgery was classified by International Classification of Diseases, Ninth Revision diagnostic codes to identify isolated occlusive indications as well as combined occlusive disease and AAA. Primary outcome was in-hospital mortality. Secondary outcomes were complications and discharge disposition.

RESULTS

Overall, 56,374 underwent aortic reconstruction, 48,591 for occlusive disease (86.2%) and 7783 for combined occlusive disease with AAA (13.8%). Intermittent claudication was the most common indication for intervention (60.9%), whereas 39.7% underwent intervention for critical limb ischemia (22.2% rest pain, 17.6% gangrene). Patients with intermittent claudication had more concomitant AAAs (17.3%) than did patients with critical limb ischemia (8.4%). The baseline characteristics for those with occlusive disease and combined occlusive with AAA disease were similar in terms of obesity (4.8% vs 4.2%; P = .27) and congestive heart failure (6.6% vs 6.3%; P = .65) but differed by age (62.2 years vs 68.4 years; P < .0001) and hypertension (65.4% vs 69.1%; P = .005). Patients with combined occlusive and AAA disease had higher mortality than those with occlusive disease alone (3.9% vs 2.7%; P = .01). On multivariable regression, factors associated with in-hospital mortality included gangrene with AAA compared with gangrene alone (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.6-4.7; P < .0002), age >65 years age (OR, 3.1; 95% CI, 2.4-4.1; P < .0001), renal failure (OR, 2.7; 95% CI, 1.9-3.8; P < .0001), and concurrent lower extremity revascularization (OR, 1.3; 95% CI, 1.1-1.7; P < .02).

CONCLUSIONS

Intermittent claudication or critical limb ischemia with concomitant AAA carries a higher mortality than intermittent claudication or critical limb ischemia alone, especially in older patients with gangrene requiring revascularization and renal insufficiency. Preoperative risk stratification strategies should focus on the indication for surgery as well as the presence of concomitant AAA.

Endovascular Aortic Aneurysm and Dissection Repair (EVAR) in Iran: Descriptive Midterm Follow-up Results

Background:

Endovascular repair of aorta in comparison to open surgery has a low early operative mortality rate, but its long-term results are uncertain.

Objectives:

The current study describes for the first time our initial four-year experience of elective endovascular aortic repair (EVAR) at Tehran heart center, the first and a major referral heart center in Iran, as a pioneer of EVAR in Iran.

Patients and Methods:

A total of 51 patients (46 men) who had the diagnosis of either an abdominal aortic aneurysm (AAA) (n = 36), thoracic aortic aneurysm (TAA) (n = 7), or thoracic aortic dissection (TAD) (n = 8) who had undergone EVAR by Medtronic stent grafts by our team between December 2006 and June 2009 were reviewed.

Results:

The rate of in-hospital aneurysm-related deaths in the group with AAA stood at 2.8% (one case), while there was no in-hospital mortality in the other groups. All patients were followed up for 13-18 months. The cumulative death rate in follow-up was nine cases from the total 51 cases (18%), out of which six cases were in the AAA group (four patients due to non-cardiac causes and two patients due to aneurysm-related causes), one case in the TAA group (following a severe hemoptysis), and two cases in the TAD group (following an expansion of dissection from re-entrance). The major event-free survival rate was 80.7% for endovascular repair of AAA, 85.7% for endovascular repair of TAA, and 65.6% for endovascular repair of TAD.

Conclusion:

The endovascular stent-graft repair of the abdominal and thoracic aortic aneurysm and aortic dissection had high technical success rates in tandem with low-rate early mortality and morbidity, short hospital stay, and acceptable mid-term free symptom survival among Iranian patients.

The impact of the establishment of a surgical high dependency unit on management of Abdominal Aortic Aneurysm

BACKGROUND

Our ability to maintain satisfactory levels of outcome after elective abdominal aortic aneurysm (AAA) surgery is increasingly strained by rising levels of co-morbidity in the presenting population. In this study we present a comparative outcome analysis of patients undergoing elective AAA surgery 18 months before and after the establishment of a surgical high dependency unit (HDU).

METHODS

The preoperative status (ASA and POSSUM scores), operative factors and postoperative outcomes as well as duration of stay were calculated for 104 patients undergoing elective AAA repair (57 prior to the HDU opening and 47 patients afterwards).

RESULTS

Patients undergoing surgery in the latter period had significantly higher ASA (2.5 +/- 0.06 versus 2.7 +/- 0.7; p = 0.007), overall POSSUM (33.2 +/- 0.5 versus 35.5 +/- 0.8; p = 0.02) and physiological POSSUM (16.3 +/- 0.3 versus 15.5 +/- 0.2; p = 0.048) scores than those operated on prior to establishment of the HDU (data are mean +/- SEM; 2-tailed p-score). The two groups had similar total lengths of hospital stay (518 versus 534 days). However, following establishment of the HDU patients occupied fewer ICU bed days (110 versus 181). This resulted in a saving of Euro 50,750.

CONCLUSION

The efficiency and quality of care following elective AAA surgery can be improved by provision of HDU step-down facilities without significantly increased expenditure.

Embolization of the internal iliac artery before EVAR: is it effective? Is it safe? Which technique should be used?

PURPOSE

To assess the clinical outcomes of internal iliac artery (IIA) embolization before endovascular aneurysm repair (EVAR).

METHODS

Between 2002 and 2011, 88 patients underwent IIA embolization prior to EVAR. Sixty-five patients underwent unilateral and 23 underwent bilateral IIA embolization. A total of 111 IIAs were embolized: 56 were embolized with coils, 41 with Amplatzer plugs, and 14 with a combination of embolic agents. The outcomes were assessed retrospectively by reviewing medical records and follow-up imaging.

RESULTS

IIA embolization was technically successful in 95.7% of cases. Type 2 endoleak from previously embolized IIAs was seen in 4 cases, and in 1 case this was significant necessitating re-intervention. Buttock claudication was reported in 38% of cases, whereas new onset erectile dysfunction occurred in 10% of cases. No severe ischemic complications, such as spinal cord ischaemia or buttock necrosis, were reported. Analysis comparing unilateral versus bilateral embolization, simultaneous versus sequential embolization, and the type of embolic material used showed no statistical significance.

CONCLUSION

IIA embolization is technically successful and effective in preventing significant type 2 endoleak in the majority of cases. It is a relatively safe procedure without major complications, but the incidence of buttock claudication and erectile dysfunction remain relatively high, and patients should be consented appropriately. There is no significant benefit for adopting a particular embolization technique, but there is a tendency towards reduced pelvic ischaemia with proximal embolization. Four cases of type II endoleak occurring after technically successful IIA embolization supports the school of thought that IIA should be embolized prior to coverage and extension of the distal landing zone.

Risk factors for postoperative complications after open infrarenal abdominal aortic aneurysm repair in Koreans

Purpose

Open infrarenal abdominal aortic aneurysm (AAA) repair is performed without event in most cases. However, some patients suffer major morbidities such as renal failure, myocardial infarction, paraplegia, acute respiratory distress syndrome, or hepatic dysfunction. Predicting what kinds of patient populations are more prone to develop such complications may keep the clinicians more attentive to the patients, possibly leading to better prognoses. In this retrospective study, we searched the incidence of and risk factors for postoperative complications and their predictive equations in 162 patients who underwent open infrarenal AAA repair.

Materials and Methods

Postoperative complications were observed within 30 days. Patient characteristics, types of aneurysm and surgery, and hemodynamic and metabolic variables during the periclamp period were analyzed in relation to postoperative complications using multiple logistic regression analysis.

Results

Postoperative complications involved the cardiac (20%), pulmonary (14%), renal (13%), gastrointestinal (6%), hepatic (3.1%), and neurologic (2.5%) systems, and bleeding occurred in 1.2% of cases. The mortality rate was 5.6%. The risk factors were age [> 67 yrs, odds ratio (OR) 2.6], clamp duration (> 110 min, OR 4.7), volume of blood transfusion (> 1,280 mL, OR 4.4), emergency operation (OR 1.4), and vasopressor infusion during clamp (OR 1.4). The prediction model was: P(x) = exp(α)/[1 + exp(α)] α;-2.2 + 0.9 × age + 1.5 × clamp duration + 1.5 × transfusion + 0.3 × emergency + 0.4 × vasopressor infusion [insert 1 if risk factors exist, otherwise, insert 0 to each variable].

Conclusion

A significant number of complications occurred after infrarenal AAA repair. Therefore, creating a protocol to identify and monitor high risk patients would improve postoperative care.

Assessing the quality of surgical care in vascular surgery; moving from outcome towards structural and process measures

OBJECTIVES

This study presents a review of studies reporting on quality of care in vascular surgery. The aim of this study was to provide insight in quality improvement initiatives in vascular surgery.

DESIGN

Original data were collected from MEDLINE and EMBASE databases. Inclusion criteria were: description of one of the three factors of quality of care, e.g. process, outcome or structure and prospectively described. All articles identified were ascribed to a domain of quality of care.

RESULTS

57 prospective articles were included, drawn from 859 eligible reports. Structure as an indicator of quality of care was described in 19 reports, process in 7 reports and outcome in 31 reports. Most studies based on structural measures considered the introduction of a clinical pathway or a registration system. Reports based on process measures showed promising results. Outcome as clinical indicator mainly focussed on identifying risk factors for morbidity, mortality or failure of treatment.

CONCLUSIONS

Structure and process indicators are evaluated scarcely in vascular surgery. Many studies in vascular surgery have been focussed on outcomes as indicator of quality of care, but a shift towards process measures should be considered as focus of attention in the future.

Volume-outcome relationships in vascular surgery: the current status

Vascular surgery has been widely practiced in hospitals within a general surgical service, although the consequent workload of individual vascular units has been small. There is an increasing body of evidence in favor of a positive relationship between hospital and surgeon volumes and the outcome of arterial surgery. These relationships suggest that vascular surgical procedures might be best placed within a centralized model of care to increase volume and thereby attain best outcomes. This systematic review appraises the current evidence for volume-outcome relationships in vascular surgery from a number of healthcare systems to examine the basis for centralization of vascular surgical services. The index procedures addressed in this review are open or endovascular repair of abdominal aortic aneurysm (AAA), ruptured AAA, descending thoracic aortic aneurysm, and thoracoabdominal aortic aneurysm, along with carotid endarterectomy and lower extremity arterial bypass.

Propensity scored analysis of outcomes after ruptured abdominal aortic aneurysm

Background

This study examined the population outcome of ruptured abdominal aortic aneurysm (rAAA) in England, the role of endovascular repair (EVAR), and the relationship between outcome and hospital workload.

Methods

Data were retrieved from Hospital Episode Statistics between 1 April 2003 and 31 March 2008. Propensity scoring was used to compare the outcomes of stratified patients undergoing EVAR and open repair. The relationship between workload and outcome was determined.

Results

Some 3725 urgent and 4414 rAAA repairs were included. Mortality rates were 21·3 per cent for urgent repair and 46·3 per cent for rAAA repair. EVAR was employed for 16·3 and 7·6 per cent of urgent and rAAA repairs respectively. EVAR was associated with significantly reduced mortality for urgent repair (odds ratio (OR) 0·531, 95 per cent confidence interval 0·415 to 0·680; P &lt; 0·001) and rAAA repair (OR 0·527, 0·416 to 0·668; P &lt; 0·001). A propensity scored analysis confirmed the benefit of EVAR for rAAA repair (P &lt; 0·001). Repair of rAAA at hospitals with a higher elective aneurysm workload was associated with lower mortality rates irrespective of the mode of treatment (P &lt; 0·001). Higher-volume hospitals were more likely to operate on rAAA (P = 0·033).

Conclusion

EVAR offered a survival advantage over open repair for non-elective aneurysm procedures. Services for the treatment of rAAA should incorporate access to EVAR and would benefit from being based in units with a high elective caseload.

Preliminary results of a prospective randomized trial of restrictive versus standard fluid regime in elective open abdominal aortic aneurysm repair

BACKGROUND

Open abdominal aortic aneurysm (AAA) repair is associated with a significant morbidity (primarily respiratory and cardiac complications) and an overall mortality rate of 4% to 10%. We tested the hypothesis that perioperative fluid restriction would reduce complications and improve outcome after elective open AAA repair.

METHODS

In a prospective randomized control trial, patients undergoing elective open infra-renal AAA repair were randomized to a "standard" or "restricted" perioperative fluid administration group. Primary outcome measure was rate of major complications (MC) after AAA repair and secondary outcome measures included: Sequential Organ Failure Assessment Score; FiO2/PO2 ratio; Urinary Albumin/Creatinine Ratio; Length-of-stay in, intensive care unit, high dependency unit, in-hospital. This prospective Randomized Controlled Trial was registered in a publicly accessible database and has the following ID number ISRCTN27753612.

RESULTS

Overall 22 patients were randomized, 1 was excluded on a priori criteria, leaving standard group (11) and restricted group (10) for analysis. No significant difference was noted between groups in respect to age, gender, American Society Anesthesiology class, Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity scores, operation time, and operation blood loss. There were no in-hospital deaths and no 30-day mortality. The cumulative fluid balance on day 5 postoperative was for standard group, 8242 +/- 714 mL, compared with restricted group, 2570 +/- 977 mL, P < 0.01. MC were significantly reduced in the restricted group (n = 10), 1 MC, compared with standard group (n = 11), 14 MC, P < 0.024. Total and postoperative length-of-stay in-hospital was significantly reduced in the restricted group, 9 +/- 1 and 8 +/- 1 days, compared with standard group, 18 +/- 5 and 16 +/- 5 days, P < 0.01 and P < 0.025, respectively.

CONCLUSIONS

Serious complications are common after elective open AAA repair, and we have shown for the first time that a restricted perioperative fluid regimen can prevent MC and significantly reduce overall hospital stay.

Mortality and utilisation of critical care resources amongst high-risk surgical patients in a large NHS trust

Previous reports describe a population of non-cardiac surgical patients at high risk of complications and death. Outcomes are sub-optimal for such patients, perhaps in part related to inadequate provision or ineffective utilisation of critical care resources. In this study, data describing 26,051 in-patient non-cardiac surgical procedures performed in a large NHS Trust between April 2002 and March 2005 were extracted from local databases. Of these procedures, 2 414 (9.3%) were high risk with an overall mortality rate of 12.2% and a prolonged hospital stay (high-risk population median (IQR) 16 (9-30) days vs standard risk 3 (2-6) days). Mortality rates for specific procedures were consistent with UK averages. However, only 852 (35.3%) high-risk patients were admitted to a critical care unit at any stage after surgery. Of 294 high-risk patients who died, only 144 (49.0%) were admitted to a critical care unit at any time and only 75 (25.6%) of these deaths occurred within a critical care area. Mortality rates were high amongst patients discharged and readmitted to critical care (37.7%) and amongst those admitted to critical care following initial postoperative care on a standard ward (29.9%). These data suggest that the outcome of high-risk general surgical patients could be improved by adequate provision and more effective utilisation of critical care resources.

Perioperative use of statins in noncardiac surgery

BACKGROUND

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) can significantly decrease cardiovascular mortality and morbidity, irrespective of the patients' cholesterol status. This paper reviews the effects of perioperative statin therapy in patients undergoing noncardiac surgery.

METHOD

A systematic literature review was undertaken of all published literature on this subject using Medline and cross-referenced. All published relevant papers on the perioperative use of statins were used.

RESULTS

Perioperative statin therapy is associated with a lower perioperative morbidity and mortality in patients undergoing elective or emergency surgery. The effects are due to a combination of lipid-lowering and pleiotropic properties of statins.

CONCLUSION

Ideally a large scale multi-centre randomized controlled trial of perioperative statin therapy should be performed but this may be difficult to conduct since there is already overwhelming evidence in the literature to suggest perioperative cardiovascular protective properties. Statins may still be under-prescribed in surgical patients.

Endovascular Ruptured Abdominal Aortic Aneurysm Repair (EVRAR): A Systematic Review

BACKGROUND

To review evidence supporting the use of endovascular ruptured aneurysm repair (EVRAR) for treatment of ruptured abdominal aortic aneurysm (RAAA).

METHODS

A systematic review of the medical literature was performed for relevant studies. We searched a number of electronic databases and hand-searched relevant journals until November 2006 to identify studies for inclusion. We considered studies in which patients with a confirmed ruptured abdominal aortic aneurysm were treated with EVRAR, which reported endpoints of mortality and major complications.

RESULTS

There was 1 randomised controlled trial (RCT), 33 non-randomised case series (24 retrospective and 9 prospective) reports were identified comparing EVRAR (n=891) with conventional open surgical repair for the treatment of RAAA. Whilst no benefit in the primary outcome of mortality was noted in the only RCT, evidence from non-randomised studies suggest that EVRAR is feasible in selected patients, where it may be associated with a trend towards reductions in blood loss, duration of intensive care treatment, early complications, and mortality.

CONCLUSIONS

For the treatment of symptomatic or ruptured abdominal aortic aneurysm, emergency endovascular repair (EVRAR) is feasible in selected patients, with early outcomes comparable to best conventional open surgical repair for the treatment of RAAA.

Positive fluid balance is associated with complications after elective open infrarenal abdominal aortic aneurysm repair

BACKGROUND

Open abdominal aortic aneurysm (AAA) repair is associated with cardiac and respiratory complications and an overall mortality rate of 2 to 8%. We hypothesised that excessive fluid administration during the perioperative period contributes to complications and poor outcome after AAA repair.

METHODS

This was a retrospective cohort study. Medical records were analysed for fluid balance and complications in 100 consecutive patients treated by open AAA repair at a single centre between 2002-2005. Mortality and all major adverse events (MAE) such as myocardial infarction (MI), cardiac arrhythmia (Arr), pulmonary oedema (PO), pulmonary infection (PI), and acute renal failure (ARF) were included in the analysis. Level of care and hospital stay, were also recorded.

RESULTS

There were no in-hospital deaths. MAE occurred in 40/100 (40%): MI (6%); Arr (14%); PO (14%); PI (25%); ARF (8%). Complications were not predicted by preoperative cardiovascular risk factors, operative and clamp time, or blood loss. Patients with complications had significantly greater cumulative positive fluid balance on postoperative day 0 (p<0.01), day 1 (p<0.05), day 2 (p<0.03) and day 3 (p<0.04). This relationship also existed for individual complications such as MI, and pulmonary oedema. These patients had significantly longer ICU/HDU (p<0.002) and hospital stay (p<0.0001).

CONCLUSIONS

Serious complications are common after elective open AAA repair, and we have shown that positive fluid balance is predictive of major adverse events increased HDU/ICU and overall hospital stay.

Different Disease Profiles for Women and Men with Abdominal Aortic Aneurysms

OBJECTIVE

The overall aim with this study was to investigate causes of death and mortality rates for women and men treated for abdominal aortic aneurysm (AAA) in Sweden.

MATERIALS AND METHOD

All patients treated for ruptured and non-ruptured AAA 1987-2002 in Sweden were identified in national registries (n=12917). Age, sex, diagnosis, surgical procedure and mortality were analysed on a patient specific level. Logistic regression and analysis of standardised mortality rates (SMR) were performed.

RESULTS

Post operative mortality was similar between the sexes. Age (p<0.0001), and surgery for rupture (p=0.0005), but not gender (p=0.65) were significant risk factor for poor long term survival. SMR revealed increased risk for both sexes compared to the population with significantly higher values for women than men (2.26, CI 2.10-2.43 vs. 1.63, CI 1.57-1.68, p<0.0001). The higher risk for women could be explained by the higher risk for aneurysm related death (ie.thoracic or abdominal aorta) compared to men (Hazard ratio 1.57 vs. 1.0, p<0.0001).

CONCLUSION

Women do not have an increased surgical risk compared to men, but treated women have an increased risk of premature death compared to men and women in the population. They also have a higher risk for aneurysm related death compared to men with AAA.

Elective surgery for aortic abdominal aneurysm: comparison of English outcomes with those elsewhere

INTRODUCTION

The aim of this study was to quantify mortality after elective repair of abdominal aortic aneurysm (AAA) in England, and to compare English case fatality rates (CFRs) with those reported in the literature.

PATIENTS AND METHODS

English Hospital Episode Statistics (HES) for the financial years 1998/9 to 2001/2, linked to death data, were analysed. A systematic literature search was undertaken to identify studies reporting CFRs after elective AAA surgery. The CFR in England was compared with these studies by using confidence intervals on the CFRs and funnel plot techniques.

RESULTS

In the English study, elective repair of AAA was performed on 11,338 patients of whom 771 died within 30 days after surgery (6.8%). The literature search found 66 studies: 34 reported mortality rates that were within the 99% confidence limits of the English rates, 31 below, and one study above.

DISCUSSION

The CFR after elective surgical repair in England within 30 days of operation (6.8%) was higher than expected from the literature. Differences between England and other countries in quality of care is one possible explanation for the findings, but other explanations are possible and are discussed.

Influence of sex on expansion rate of abdominal aortic aneurysms

BACKGROUND

The UK Small Aneurysm Trial suggested that female sex is an independent risk factor for rupture of abdominal aortic aneurysm (AAA). This study assessed the effect of sex on the growth rate of AAA.

METHODS

Between January 1985 and August 2005 all patients who were referred to the Royal Infirmary of Edinburgh with an AAA who were not considered for early aneurysm repair were assessed by serial abdominal ultrasonography. Maximum anteroposterior and transverse diameters of the AAAs were measured.

RESULTS

A total of 1255 patients (824 men and 431 women) were followed up for a median of 30 (range 6-185) months. A median of six examinations (range 2-37) was performed for each patient. Median diameter on initial examination was 41 (range 25-83) mm. Median growth rate overall was 2.79 (range - 4.80-37.02) mm per year. Median growth rate of AAA was significantly greater in women than men (3.67 (range - 1.2-37.02) versus 2.03 (range - 4.80-21.00) mm per year; P < 0.01). Weighted linear regression analysis revealed that large initial anteroposterior AAA diameter and female sex were significant predictors of faster aneurysm growth rate (P < 0.001 and P = 0.006 respectively).

CONCLUSION

The growth rate of AAA was significantly greater in women than in men. This may have implications for the frequency of follow-up and timing of repair of AAA in women.

Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery

Background

This study investigated the volume–outcome relationship for abdominal aortic aneurysm (AAA) surgery and quantified critical volume thresholds.

Methods

PubMed, EMBASE and the Cochrane library were searched for articles on the operation volume–outcome relationship in elective and ruptured AAA surgery. UK Hospital Episode Statistics data were also considered. Elective and ruptured AAA repairs were dealt with separately. The data were meta-analysed, and the odds ratios (95 per cent confidence interval) for mortality at higher- and lower-volume hospitals were compared. Volume thresholds were identified from each paper.

Results

The analysis included 421 299 elective and 45 796 ruptured AAA operations. Significant relationships between mortality and annual volume were noted for both groups. Overall, the weighted odds ratio was 0·66 (0·65 to 0·67) for elective repair at a threshold of 43 AAAs per annum and 0·78 (0·73 to 0·82) for ruptured aneurysm repair at a threshold of 15 AAAs per annum, both in favour of high-volume institutions.

Conclusion

Higher annual operation volumes are associated with significantly lower mortality in both elective and ruptured AAA repair. This suggests that AAA surgery should be performed only at higher-volume centres.

Transfusion requirements and outcomes in patients undergoing abdominal aortic surgery using intra-operative cell salvage

BACKGROUND

Intraoperative cell salvage (ICS) is the recovery, anticoagulation, filtration and reinfusion of blood lost during surgery. The aim of this study is to determine the safety and efficacy of ICS in emergency and elective abdominal aortic surgery.

METHODS

This study reviews volumes of blood loss, blood salvaged with ICS, allogenic blood requirements, and clinical outcomes in patients undergoing abdominal aortic surgery using ICS.

RESULTS

Seventy-nine patients undergoing abdominal aortic surgery are included. Supplemental allogenic blood was not required in 45/79 (57%) of all patients. Transfusion with allogenic blood was not necessary in 41/63 (66%) of elective abdominal aortic aneurysm repairs. ICS was associated with no major complications.

CONCLUSION

ICS is a safe procedure and substantially reduces the need for blood transfusion in patients undergoing abdominal aortic surgery. It may substantially alleviate shortages of allogenic blood and should be part of the armamentarium of vascular units.

Medical Optimisation Can Reduce Morbidity and Mortality Associated with Elective Aortic Aneurysm Repair

OBJECTIVES

Patients with aortic aneurysms have significant comorbidities which influence outcome. Our practice includes comprehensive assessment to identify comorbidities, allowing subsequent medical optimisation prior to aneurysm repair. The aim of this study was to assess this process and to identify any factors predictive of outcome.

DESIGN

Prospective observational study.

MATERIALS

Medical case notes of 200 patients referred with aortic pathology.

METHODS

Data analysed included preoperative, perioperative and postoperative factors. Multiple logistic regression analysis was performed to identify predictors of outcome.

RESULTS

Following assessment 17 patients (8.5%) were found to be unfit for intervention and 165 patients (82.5%) proceeded to aneurysm repair. In this group assessment uncovered previously undiagnosed cardiac, respiratory and renal comorbidity in 19%, 57% and 29% of patients respectively. Multiple logistic regression analysis indicated that optimisation by a renal physician reduced post-operative renal impairment (OR 0.12, 95% CI 0.03-0.45, P=0.002) while optimisation by a cardiologist reduced respiratory complications (OR 0.7, 95% CI 0.05-0.99, P=0.049). An abnormal echocardiogram was associated with pneumonia (OR 6.9, 95% CI 1.6-29, P=0.01) and death (OR 7.9, 95% CI 1.15-54, P=0.036).

CONCLUSION

Pre-operative assessment identifies previously undiagnosed comorbidity in a significant proportion of patients. Subsequent medical optimisation may reduce post-operative morbidity and mortality.

Identification and characterisation of the high-risk surgical population in the United Kingdom

Introduction

Little is known about mortality rates following general surgical procedures in the United Kingdom. Deaths are most common in the 'high-risk' surgical population consisting mainly of older patients, with coexisting medical disease, who undergo major surgery. Only limited data are presently available to describe this population. The aim of the present study was to estimate the size of the high-risk general surgical population and to describe the outcome and intensive care unit (ICU) resource use.

Methods

Data on inpatient general surgical procedures and ICU admissions in 94 National Health Service hospitals between January 1999 and October 2004 were extracted from the Intensive Care National Audit & Research Centre database and the CHKS database. High-risk surgical procedures were defined prospectively as those for which the mortality rate was 5% or greater.

Results

There were 4,117,727 surgical procedures; 2,893,432 were elective (12,704 deaths; 0.44%) and 1,224,295 were emergencies (65,674 deaths; 5.4%). A high-risk population of 513,924 patients was identified (63,340 deaths; 12.3%), which accounted for 83.8% of deaths but for only 12.5% of procedures. This population had a prolonged hospital stay (median, 16 days; interquartile range, 9–29 days). There were 59,424 ICU admissions (11,398 deaths; 19%). Among admissions directly to the ICU following surgery, there were 31,633 elective admissions with 3,199 deaths (10.1%) and 24,764 emergency admissions with 7,084 deaths (28.6%). The ICU stays were short (median, 1.6 days; interquartile range, 0.8–3.7 days) but hospital admissions for those admitted to the ICU were prolonged (median, 16 days; interquartile range, 10–30 days). Among the ICU population, 40.8% of deaths occurred after the initial discharge from the ICU. The highest mortality rate (39%) occurred in the population admitted to the ICU following initial postoperative care on a standard ward.

Conclusion

A large high-risk surgical population accounts for 12.5% of surgical procedures but for more than 80% of deaths. Despite high mortality rates, fewer than 15% of these patients are admitted to the ICU.

Influence of presentation on outcome in abdominal aortic aneurysm repair

OBJECTIVES

In the absence of formal screening abdominal aortic aneurysms (AAA) are detected in an opportunistic manner. Many remain asymptomatic and undetected until they rupture. Incidentally discovered small AAAs are entered into a surveillance programme until they reach a suitable size for repair. The aim of this study was to examine trends in the management of AAA and whether the method of presentation had an effect on subsequent mortality.

DESIGN

Observational study in UK district general hospital.

MATERIALS/METHODS

This study reports a single surgeon case series identified using a prospectively maintained database. Data on mode of presentation, management and mortality were retrieved from case notes, PIMS hospital database and the Office of National Statistics.

RESULTS

Two hundred and five patients were referred with AAAs between 1992 and 2004, 78% presenting in elective circumstances. The surveillance programme fed 33% of the operated cases. Two aneurysms ruptured whilst under surveillance. Overall elective operative mortality was 11.8% and has progressively decreased over time. Thirty-day operated mortality was significantly lower in patients having a period of surveillance than those having immediate elective repair (2.3 vs. 16.3%, p=0.018). A slight reduction in emergency AAA repairs was noted over the study period (r2=0.6) although registered aneurysm deaths continue to increase (r2=0.83).

CONCLUSIONS

Elective mortality following AAA surgery decreased over the study period. Outcome was better in those patients who had surgery for aneurysms that had been under surveillance. Despite opportunistic screening the population adjusted mortality rate of aortic aneurysms showed a progressive increase. A reduction in deaths from aneurysms is unlikely without a formal screening programme.

The impact of a consultant anaesthetist led pre-operative assessment clinic on patients undergoing major vascular surgery*

Summary Patients undergoing major vascular surgery are at high risk of peri-operative morbidity and mortality owing to a combination of advanced age, significant co-morbidity and the nature of the surgery. A consultant-led pre-operative assessment clinic provides an opportunity to stratify these patients on the basis of risk in advance of surgery, to make timely multidisciplinary referrals where appropriate, and to prescribe medical therapies according to the current best evidence. This results in fewer last-minute cancellations for medical reasons and increased patient satisfaction, and may improve patient outcome. Such a clinic also provides an educational arena for nursing and trainee medical staff, and importantly allows those patients in whom the risks are felt to outweigh the potential benefits of surgery to be managed in a more fully informed manner.

Defining the role of endovascular therapy in the treatment of abdominal aortic aneurysm: results of a prospective randomized trial

Following publication of early registry data showing poor durability for first-generation endografts, EVAR was labeled by some as a failed experiment. The EVAR trial results prove such a pessimistic appraisal of EVAR wrong. In patients fit for open AAA repair EVAR w ith current devicesachieves a 3% benefit in operative and 4-year aneurysm-related mortality compared with open surgery. In patients unfit for open repair 30-day mortality is significantly greater and can no longer be described as safe. Nor does EVAR affect aneurysm-related or all-cause mortality in the 4-year follow-up. EVAR, at least for the first 4 years, is not safe or effective. Based on these results it seems appropriate in unfit patients to attend to concurrent medical problems before considering intervention for an asymptomatic aneurysm. Before the publication of this trial it was generally believed that EVAR would be of benefit in such patients; indeed, it was for the high-risk patient that EVAR was originally conceived. The focus changes from urgency to deploy EVAR to improvement of fitness, recognizing that such patients are very sick with multiple comorbidities. In both fit and unfit patients with large aneurysms most late deaths were cardiovascular related. The importance of risk factor management in both patient groups cannot be overstated. Despite the cost implications of EVAR and its failure to improve mid-term all-cause mortality over open AAA repair it is likely that the bias of both patients and surgeons toward this minimally invasive procedure means that it will continue to have a significant role. Experience and endograft developments have the potential to reduce postoperative complications; surveillance strategies could then be amended to reduce cost implications. Alternatively, over time the currently static rate of complications may increase as endografts reach the end of their working life. The long-term follow-up of patients in both the both EVAR Trials 1 and 2 has the potential for future surprises.

The role of cardiopulmonary fitness and its genetic influences on surgical outcomes

Background

Outcome after major surgery remains poor in some patients. There is an increasing need to identify this cohort and develop strategies to reduce postsurgical morbidity and mortality. Central to outcome is the ability to mount cardiovascular output in response to the increased oxygen demand associated with major surgery.

Methods

A medline search was performed using keywords to identify factors that affect, and genetic influences in, disease and outcome from surgery, and all relevant English language articles published between 1980 and 2005 were retrieved. Secondary references were obtained from key articles.

Results

Preoperative cardiopulmonary exercise testing assesses patient fitness, highlights those at particular risk and, combined with triage to critical care, facilitates significant improvement in surgical outcome. However, genetic factors also influence responses to increased oxygen demand, and some patients are genetically predisposed to mounting increased inflammatory responses, which raise oxygen demand further. Polymorphisms in genes influencing fitness (angiotensin converting enzyme) and immune and inflammatory responses (such as interleukin 6) may associate with surgical outcome.

Conclusions

Development of preoperative screening methods like cardiopulmonary exercise testing and genotype analysis to identify index factors may permit better patient stratification, provide targets for future tailored treatments and so improve surgical outcome.

Overnight Intensive Recovery: Elective Open Aortic Surgery Without a Routine ICU Bed

OBJECTIVES

Most patients are managed on the intensive care unit (ICU) after elective open aortic surgery. We preoperatively identify patients suitable for extubation in theatre with overnight management in theatre recovery before discharge back to the ward (overnight intensive recovery (OIR)). The safety of this was investigated.

DESIGN

Retrospective case note analysis of all patients who underwent EOAS from 1998 to 2002, recording in-hospital morbidity and mortality. Physiological and operative severity score for the enUmeration of mortality and morbidity (POSSUM) data were collected prospectively.

METHODS

Patients were divided into those selected for OIR and those booked for elective ICU admission. Observed morbidity and mortality data were compared with predicted outcomes generated by Portsmouth-POSSUM and POSSUM equations.

RESULTS

Hundred and fifty-two out of 178 patients used OIR; 155 patients had abdominal aortic aneurysm (AAA) repair. The elective ICU group had significantly higher anaesthetic risk scores (ASA grade), larger AAA, greater intraoperative blood loss and longer operations. In the OIR group, ten patients (7%) needed ICU admission within 48h postoperatively. Complications occurred in 85/152, with two deaths. There was no excess morbidity or mortality in the OIR group (predicted 95% CI 83-105 and 5-17, respectively).

CONCLUSION

Most patients having elective open aortic surgery can be managed safely using OIR.

Elective Open Operation for Abdominal Aortic Aneurysm in Octogenarians—Survival Analysis of 105 Patients

OBJECTIVES

To study early mortality and long-term survival of patients more than 80 years of age having elective open repair for abdominal aortic aneurysm (AAA).

DESIGN

Retrospective multicenter cohort study.

MATERIAL

One hundred and five patients, 23 women and 82 men, with a median age of 82 years, operated at three Norwegian hospitals during the period 1983-2002.

METHOD

Survival analyses were based on data from medical records and the Norwegian Registrar's Office of Births and Deaths. Expected survival was based on mortality rates of the general population, matched by age, sex, and calendar period. Relative survival was calculated as the ratio between the observed and the expected survival.

RESULTS

During the study period there has been a 10 fold increase in octogenarians treated with open operation for AAA. Early mortality (30-day) for the whole group of patients was 10.5% (95% confidence interval (95% CI) 5.3-18.0), and similar for both genders. The 5-year survival rate was 47% (95% CI 35.9-57.4), and not significantly different from that of a matched group in the general population. Patients aged 84 years or more had a median survival time of 35 months (95% CI 18.5-51.6).

CONCLUSION

The number of AAA operations in octogenarians has increased considerably during 20 years. Octogenarians operated electively for AAA has higher 30-day mortality as compared to younger patients. Their long-term survival appears similar to a matched control group. The benefit of surgery must be carefully considered against the perioperative risk, especially for the oldest octogenarians.

Randomized clinical trial of intraoperative autotransfusion in surgery for abdominal aortic aneurysm

Background

Perioperative homologous blood transfusion (HBT) is associated with adverse reactions and risks transmission of infection. It has also been implicated as an immunosuppressive agent. Intraoperative autotransfusion (IAT) is a potential method of autologous transfusion.

Methods

This was a single-centre randomized clinical trial of IAT in surgery for abdominal aortic aneurysm. Forty patients were randomized to IAT and 41 underwent surgery with HBT only. Patients in both groups received HBT to maintain haemoglobin levels above 8 g/dl. Transfusion requirements, and incidence of systemic inflammatory response syndrome (SIRS) and infection, were compared.

Results

Significantly fewer patients in the IAT group required HBT (21 versus 31; P = 0·038) and the median blood requirement per patient was 2 units lower (P = 0·012). There was a higher incidence of chest infection (12 versus four patients; P = 0·049) and SIRS (20 versus nine patients; P = 0·020) in the HBT group. Risk of SIRS was related to aortic cross-clamp time in the IAT group only.

Conclusion

Use of autotransfusion effectively reduced the need for HBT and was associated with a reduced incidence of postoperative SIRS and infective complications.

Choice of anesthetics

The choice of anesthetics for vascular surgical patients is not only determined by the kind and extent of the surgical procedure but also by patient comorbidities. Frequently, patients have a history of hypertension, peripheral vascular and coronary artery disease,cerebrovascular disease, and renal impairment. The goal of the chosen anesthetic technique is to protect organ function, mainly of the brain and the heart. In some instances regional anesthesia might be preferred, but no difference in outcome between the two techniques has been shown conclusively. Vascular emergencies are particularly challenging for the anesthesiologist, but in recent years the development of stent graft insertion has improved the short-term outcome in many of these procedures.

Routine Measurement of Radioisotope Left Ventricular Ejection Fraction Prior to Vascular Surgery: Is it Worthwhile?

OBJECTIVE

To determine whether estimation of left ventricular (LV) ejection fraction (EF) by means of multiple gated acquisition (MUGA) scanning could reliably stratify cardiac risk prior to elective major vascular surgery.

METHODS

A review of the English-language literature.

RESULTS AND CONCLUSIONS

Twenty-two studies enrolling a total of 3096 patients were identified from 1984 to date. Selection bias, blinding of the results, different cut-off limits, and several retrospective studies were some of the problems preventing a comprehensive analysis. The resting LVEF was not found to be a consistent predictor of perioperative ischaemic cardiac events. In the perioperative phase, poor LV function was, mainly, predictive of congestive heart failure, and, in the long-term, of cardiac outcome. The presence of myocardial wall motion abnormalities was also associated with both a higher chance of postoperative cardiac complications and a worse long-term cardiac outcome. Although measurements of LV function seem to play a key role in defining a patient's long-term prognosis, the value of routinely measuring LVEF preoperatively is limited and, therefore, MUGA scanning cannot be recommended as a general screening test. Despite this, it has been widely used for cardiac risk assessment in vascular surgery, and only recently its popularity has started declining. Other tests, such as stress-echocardiography and myocardial perfusion imaging, used selectively in moderate-risk patients can refine prediction of cardiac risk. In the future, gated stress myocardial perfusion scintigraphy, perhaps combined with ANP/BNP plasma level determination, may become a first choice test in preoperative cardiac risk assessment.

Uncovering occult operative morbidity and mortality

Take off the rose tinted spectacles