A meta-analysis of 50 years of ruptured abdominal aortic aneurysm repair

BACKGROUND

Operative repair of ruptured abdominal aortic aneurysm (RAAA) is associated with a high mortality rate but reported figures vary widely. The aim of this study was to estimate the operative mortality of RAAA repair and determine how it has changed over time.

METHODS

A meta-analysis of all English language literature quoting figures for operative mortality of RAAA repair.

RESULTS

The pooled estimate for the overall operative mortality rate of RAAA repair from 1955 to 1998 was 48 (95 per cent confidence interval 46 to 50) per cent. Meta-regression analysis of operative mortality over time demonstrated a constant reduction of approximately 3.5 per cent per decade (1954-1997) with an operative mortality rate estimate for the year 2000 of 41 per cent. Seventy-seven studies reported intraoperative mortality but, while this appears to have remained constant over time, there was evidence of the presence of publication bias in the subgroup of papers reporting this outcome. There was no evidence of publication bias for the overall operative mortality outcome.

CONCLUSION

Contrary to the conclusion of recent studies, this paper demonstrates a gradual reduction with time in the operative mortality rate of RAAA repair.

Collagen COL4A3 knockout: a mouse model for autosomal Alport syndrome

A mouse model for the autosomal form of Alport syndrome was produced. These mice develop a progressive glomerulonephritis with microhematuria and proteinuria, consistent with the human disease. End-stage renal disease develops at approximately 14 weeks of age. TEM analysis of the glomerular basement membranes (GBM) during development of renal pathology revealed focal multilaminated thickening and thinning beginning in the external capillary loops at 4 weeks and spreading throughout the GBM by 8 weeks. By 14 weeks, half of the glomeruli were fibrotic with collapsed capillaries. Immunofluorescence analysis of the GBM showed the absence of type IV collagen alpha-3, alpha-4, and alpha-5 chains and a persistence of alpha-1 and alpha-2 chains (these chains normally localize to the mesangial matrix). Northern blot analysis using probes specific for the collagen chains illustrate the absence of COL4A3 in the knockout, whereas mRNAs for the remaining chains are unchanged. An accumulation of fibronectin, heparan sulfate proteoglycan, laminin-1, and entactin was observed in the GBM of the affected animals. The temporal and spatial pattern of accumulation was consistent with that for thickening of the GBM as observed by TEM. Thus, expression of these basement membrane-associated proteins may be involved in the progression of Alport renal disease pathogenesis. The levels of mRNAs encoding the basement membrane-associated proteins at 7 weeks were unchanged.

Systematic review and meta-analysis of the early and late outcomes of open and endovascular repair of abdominal aortic aneurysm

Background

Any possible long-term benefit from endovascular (EVAR) versus open surgical repair for abdominal aortic aneurysm (AAA) remains unproven. Long-term data from the Open Versus Endovascular Repair (OVER) trial add to the debate regarding long-term all-cause and aneurysm-related mortality. The aim of this study was to investigate 30-day and long-term mortality, reintervention, rupture and morbidity after EVAR and open repair for AAA in a systematic review.

Methods

Standard PRISMA guidelines were followed. Random-effects Mantel–Haenszel meta-analysis was performed to evaluate mortality and morbidity outcomes.

Results

The existing published randomized trials, together with information from Medicare and SwedVasc databases, were included in a meta-analysis. This included 25 078 patients undergoing EVAR and 27 142 undergoing open repair for AAA. Patients who had EVAR had a significantly lower 30-day or in-hospital mortality rate (1·3 per cent versus 4·7 per cent for open repair; odds ratio (OR) 0·36, 95 per cent confidence interval 0·21 to 0·61; P < 0·001). By 2-year follow-up there was no difference in all-cause mortality (14·3 versus 15·2 per cent; OR 0·87, 0·72 to 1·06; P = 0·17), which was maintained after at least 4 years of follow-up (34·7 versus 33·8 per cent; OR 1·11, 0·91 to 1·35; P = 0·30). There was no significant difference in aneurysm-related mortality by 2 years or longer follow-up. A significantly higher proportion of patients undergoing EVAR required reintervention (P = 0·003) and suffered aneurysm rupture (P < 0·001).

Conclusion

There is no long-term survival benefit for patients who have EVAR compared with open repair for AAA. There are also significantly higher risks of reintervention and aneurysm rupture after EVAR.

Type II endoleak after endovascular aneurysm repair

BACKGROUND

The aim was to assess the risk of rupture, and determine the benefits of intervention for the treatment of type II endoleak after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

This systematic review was done according to PRISMA guidelines. Outcome data included incidence, spontaneous resolution, sac expansion, interventions, clinical success, and complications including conversion to open repair, and rupture.

RESULTS

Thirty-two non-randomized retrospective studies were included, totalling 21 744 patients who underwent EVAR. There were 1515 type II endoleaks and 393 interventions. Type II endoleak was seen in 10·2 per cent of patients after EVAR; 35·4 per cent resolved spontaneously. Fourteen patients (0·9 per cent) with isolated type II endoleak had ruptured abdominal aortic aneurysm; six of these did not have known aneurysm sac expansion. Of 393 interventions for type II endoleak, 28·5 per cent were unsuccessful. Translumbar embolization had a higher clinical success rate than transarterial embolization (81 versus 62·5 per cent respectively; P = 0·024) and fewer recurrent endoleaks were reported (19 versus 35·8 per cent; P = 0·036). Transarterial embolization also had a higher rate of complications (9·2 per cent versus none; P = 0·043).

CONCLUSION

Aortic aneurysm rupture after EVAR secondary to an isolated type II endoleak is rare (less than 1 per cent), but over a third occur in the absence of sac expansion. Translumbar embolization had a higher success rate with a lower risk of complications.

In situ replacement of infected aortic grafts with rifampicin-bonded prostheses: the Leicester experience (1992 to 1998)

PURPOSE

Prosthetic graft infection after aortic aneurysm surgery is a life-threatening complication. Treatment options include total graft excision and extra-anatomic bypass grafting or in situ replacement of the graft. The latter option is gaining increasing popularity, but the long-term outcome remains uncertain, particularly in light of the increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA). We performed a prospective nonrandomized study to assess the outcome after graft excision and in situ replacement with a rifampicin-bonded prosthesis for the treatment of major aortic graft infection.

METHODS

In a 6-year period from January 1992 to December 1997, 11 patients (eight men, three women) with major aortic graft infection underwent total graft excision and in situ replacement with a rifampicin-bonded prosthesis. The median age of the patients was 66 years (range, 49 to 78 years). Four patients had a hemorrhage from an aortoenteric fistula, three had a retroperitoneal abscess, two had graft occlusion, one had a perigraft collection shown by means of computed tomography, and one had a ruptured suprarenal false aneurysm. Organisms were cultured from 10 patients.

RESULTS

MRSA was isolated in two patients, both of whom had originally undergone repair of a ruptured abdominal aortic aneurysm. Two patients died (18.2%) within 30 days, and three patients (27.6%) had nonfatal complications (peritoneal candidiasis, transient renal impairment, and profound anorexia). Two patients died late in the follow-up period. Seven patients remain alive and clinically free of infection.

CONCLUSION

The long-term results after total graft excision and in situ replacement with a rifampicin-bonded prosthesis appear to be favorable. However, MRSA aortic graft infection appears to be associated with a poor prognosis.

Long-term results of femorotibial bypass with vein or polytetrafluoroethylene

BACKGROUND

This was a retrospective review of the long-term results of femorotibial bypass using autologous vein and polytetrafluoroethylene (PTFE) over 24 years.

METHODS

Some 518 patients who underwent 635 femorotibial bypass grafts were studied. Outcome measures analysed included primary and secondary graft patency, limb salvage rates and death.

RESULTS

Overall primary and secondary graft patencies were 62 and 67 per cent respectively at 12 months, and 44 and 48 per cent at 24 months. For vein grafts, the primary and secondary patencies were 63 and 66 per cent at 12 months, and 54 and 56 per cent at 24 months. For PTFE grafts, the primary and secondary patencies were 48 and 54 per cent at 12 months, and 31 and 37 per cent at 24 months. Limb salvage and patient survival rates were 81 and 84 per cent at 12 months, and 73 and 74 per cent at 24 months. Primary and secondary graft patencies for vein were significantly better than for PTFE (P = 0.0001). There was no difference in patency between reversed and in situ grafts.

CONCLUSION

Femorotibial bypass can produce excellent long-term results. Vein remains the conduit of choice but in the absence of vein acceptable results can be achieved with PTFE.

Intraoperative air testing of colorectal anastomoses: a prospective, randomized trial

A total of 145 consecutive patients receiving a colorectal anastomosis were randomized to 'test' or 'no test' once the anastomosis had been completed. Anastomotic testing was performed with the pelvis filled with saline and the rectum distended by sigmoidoscopic insufflation of air. Any leaks demonstrated were oversewn. A water-soluble contrast enema was performed on the tenth postoperative day. Seventy-four patients were randomized to 'test' and 71 to 'no test' but one patient was withdrawn from each group leaving a total of 143 for analysis. The two groups were well matched for age, sex, diagnosis and operative details. Eighteen (25 per cent) air leaks were detected and repaired in the 'test' group. After operation there were three (4 per cent) clinical leaks in the 'test' group and ten (14 per cent) in the 'no test' group (Fisher's exact test, P = 0.043). There were eight (11 per cent) radiological leaks in the 'test' group and 20 (29 per cent) in the 'no test' group (P = 0.006). Intraoperative air testing and repair of colorectal anastomoses significantly reduces the risk of postoperative clinical and radiological leaks.

Cytokines and inflammatory pathways in the pathogenesis of multiple organ failure following abdominal aortic aneurysm repair

Multiple organ failure is a common mode of death following abdominal aortic aneurysm repair, particularly after rupture. Cytokines are the principal mediators of the inflammatory response to injury and high levels of circulating cytokines have been associated with poor outcome in major trauma and sepsis. Abdominal aortic aneurysm repair results in an ischaemia-reperfusion injury to the tissues distal to the site of aortic clamping. The inflammatory response in these tissues causes the release of cytokines, principally Interleukins 1-beta, 6, and 8, and Tumour Necrosis Factor alpha. If released in large enough concentrations, these cytokines may enter the circulation and gain access to organs distant to the site of initial injury. Circulating cytokines cause dysfunction of the renal, cardiovascular, respiratory, nervous and musculo-skeletal systems. The combination of these individual changes in organ function is the multiple-organ dysfunction syndrome, which may progress to multiple organ failure.

Subintimal and intraluminal recanalisation of occluded crural arteries by percutaneous balloon angioplasty

Advances in radiological techniques have allowed successful treatment of arterial stenoses situated in the distal arterial tree. This paper describes the experience at Leicester Royal Infirmary with percutaneous transluminal angioplasty (PTA) for the treatment of occluded crural arteries. Over a 27 month period, 21 patients with 24 ischaemic limbs have undergone PTA for crural artery occlusion. PTA was attempted in a total of 29 occluded crural arteries with a median length of occlusion of 6 cm (range 1-30 cm). Intraluminal recanalisation was used for short occlusions and the subintimal technique for long occlusions. Technical success with angiographic recanalisation of the artery was achieved in 25 out of 29 crural vessels (86%). Endovascular treatment of crural artery occlusion appears to be a safe and effective treatment which avoids the need for femorodistal surgery in patients with occluded calf vessels.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Factors affecting the serological response of dogs and cats to rabies vaccination

After being vaccinated against rabies some cats and dogs fail to show an antibody titre adequate to meet the requirements of the UK Pet Travel Scheme. To investigate this problem, the data derived from 16,073 serum samples submitted to the Veterinary Laboratories Agency for serological testing between 1999 and 2002, 1002 samples submitted to BioBest during March and April 2001, and 1264 samples associated with one make of vaccine submitted to BioBest between June 2001 and January 2003, were analysed. The probability of antibody titre failing to reach at least 0.5 iu/ml was analysed by logistic regression as a function of the choice of vaccine, the interval between vaccination and sampling, the sex and age of the animal, and its country of origin. In dogs, all these factors, except sex, had highly significant (P < 0.001) effects on the test failure rate, and in cats all the factors had a significant effect (P < 0.05).

Angiogenesis in abdominal aortic aneurysms

OBJECTIVES

To determine the degree of neovascularisation in the wall of abdominal aortic aneurysms in comparison to atherosclerotic control aortas, and to correlate the angiogenic response with the extent of the cellular inflammatory infiltrate.

DESIGN

Histopathological study.

MATERIALS

Aortic samples were obtained from patients with abdominal aortic aneurysms and from atherosclerotic controls.

METHODS

Samples were stained with haematoxylin and eosin, and Miller's elastin and Van Gieson stain, EVG, and a monoclonal antibody specific to human endothelial cells. Within the aortic wall three histological regions were defined, the media, the adventitia and a transition zone. The number of capillary like, thin walled vessels were measured in each region, and the cellular infiltrate was quantified.

RESULTS

The number of newly formed vessels was increased in all layers of aneurysmal wall in comparison to control samples (p<0.001). The degree of neovascularisation correlated with the extent of the inflammatory infiltrate (rs=0.45, p<0.01).

CONCLUSIONS

This study demonstrated that abdominal aortic aneurysms are associated with a marked angiogenic response, which is related to the degree of inflammation within the aortic wall. It is hypothesised that anti-angiogenic agents may play a role in the medical management of aortic aneurysmal disease.

Feasibility of preoperative computer tomography in patients with ruptured abdominal aortic aneurysm: a time-to-death study in patients without operation

INTRODUCTION

Despite advances in surgery, anaesthesia, and critical care, mortality from ruptured abdominal aortic aneurysms (AAAs) has not decreased over the last 20 years. Endovascular aneurysm repair (EVAR) of ruptured AAAs is an alternative to open repair, which may improve outcome. However, a computed tomography (CT) scan is usually required to assess the anatomic suitability of the aneurysm for EVAR. This may result in delay in transferring patients to the operating room. We evaluated all patients admitted to hospital with a ruptured AAA who died without undergoing surgery, to determine time to death after AAA rupture and thus the potential time available for obtaining a CT scan.

METHODS

A retrospective case note review was conducted of 56 patients admitted to a single center with ruptured AAAs who did not undergo surgery because of advanced age or associated comorbidity over 8 years from 1995 to 2003. Statistical analysis was performed with the Fisher exact test.

RESULTS

The 56 patients (33 men, 59%; 23 women, 41%) had a median age of 85 years (range, 71-98 years). Reasons for no operation being performed were shock (9%), cardiac arrest (11%), quality of life (29%), malignancy (7%), cardiac disease (15%), respiratory disease (16%) and age (14%). Median systolic blood pressure at admission was 110 mm Hg, heart rate was 88 beats per minute, and hemoglobin concentration was 10.5 g/dL. Patients were not aggressively resuscitated once a decision was made to not perform surgery. Death within 2 hours of hospital admission occurred in 7 (12.5%) patients, and 49 (87.5%) patients died more than 2 hours after admission. Median interval between onset of symptoms and admission to hospital was 2 hours 30 minutes (range, 44 minutes-36 hours), and the median interval between admission and death was 10 hours 45 minutes (range, 1 hour 1 minute-143 hours 55 minutes). The median total time to death from onset of symptoms was 16 hours 38 minutes (range, 2 hours 6 minutes-146 hours 50 minutes).

CONCLUSION

Most (87.5%) patients admitted to hospital with a ruptured AAA died after more than 2 hours. These data show that most patients with a ruptured AAA who reach the hospital alive are sufficiently stable to undergo CT and consideration of EVAR.

The systemic inflammatory response syndrome, organ failure, and mortality after abdominal aortic aneurysm repair

BACKGROUND

Organ failure is a major cause of morbidity and mortality after abdominal aortic aneurysm (AAA) repair. The aim of this study was to determine the relationships between the systemic inflammatory response syndrome (SIRS), organ failure, and mortality after AAA repair and to determine whether the clinical monitoring of SIRS was a useful adjunct to clinical method.

METHODS

One hundred consecutive patients undergoing open AAA repair were prospectively studied. Patients were divided into three groups: those undergoing elective AAA repair, those with symptomatic but nonruptured AAA, and those with ruptured AAA. The presence of SIRS and organ failure was recorded on a daily basis for each patient until discharge or death.

RESULTS

Most patients had SIRS develop during the postoperative period: 89% of the elective group, 92% of the emergency nonruptured (urgent) group, and 100% of the ruptured group. Multiorgan failure occurred in 3.8% of the elective group, 38% of the urgent group, and 64% of the ruptured AAA group. After ruptured AAA repair, the concurrent absence of both SIRS and any organ failure for 48 hours had a sensitivity of 93% and a specificity of 91% as a predictive indicator of subsequent survival to hospital discharge. Patients in whom multiorgan failure developed after ruptured AAA repair had a significantly higher mortality rate (69%) than those who did not (0%; P =.001; 95% CI for the difference, 30.2% to 85.8%).

CONCLUSION

The differences in the incidence rate of multiorgan failure between the patient groups compared with the high incidence rate of SIRS in all patient groups supports the two-hit hypothesis of multiorgan failure. The presence of multiorgan failure after ruptured AAA repair is associated with poor outcome. The absence of SIRS and organ failure in these patients is a good predictive indicator of survival.

Outcomes of endovascular aneurysm repair in patients with hostile neck anatomy

OBJECTIVES

This study aims to evaluate outcomes following EVAR in patients with hostile neck anatomy (HNA).

METHODS

Data prospectively collected from 552 elective EVARs were analysed retrospectively. Data regarding neck morphology was obtained from aneurysm stent plans produced prior to EVAR. HNA was defined as any of; neck diameter >28 mm, neck angulation >60°, neck length <15 mm, neck thrombus, or neck flare.

RESULTS

552 patients underwent EVAR. Mean age 73.9 years, mean follow-up 4.1 years. 199 patients had HNA, 353 had favourable neck anatomy (FNA). There was a significant increase in late type I endoleaks (FNA 4.5%, HNA 9.5%; P = 0.02) and total reinterventions (FNA 11.0%, HNA 22.8%; P < 0.01), and a significant decrease in late type II endoleaks in patients with HNA (FNA 16.7%, HNA 10.6%; P < 0.05). There was no significant difference in technical success (FNA 0.6%, HNA 2.0%; p = 0.12), 30-day re-intervention (FNA 2.8%, HNA 5.0%; P = 0.12), 30-day mortality (FNA 1.1%, HNA 0.5%; P = 0.45), 30-day type I endoleaks (FNA 0.8%, HNA 2.5%; P = 0.12), 5-year mortality (FNA 15.1%, HNA 14.6%; P = 0.86), aneurysm-related mortality (FNA 1.7% versus HNA 2.0%; P = 0.79), stent-graft migration (FNA 2.5%, HNA 3.0%; P = 0.75), sac expansion (FNA 13.0%, HNA 9.5%; P = 0.22), or graft rupture (FNA 1.1%, HNA 3.5%; P = 0.05). Binary logistic regression of individual features of HNA revealed secondary intervention (P = 0.009), technical failure (P = 0.02), and late type I endoleaks (P = 0.002), were significantly increased with increased neck diameter.

CONCLUSIONS

HNA AAAs can be successfully treated with EVAR. However, surveillance is necessary to detect and treat late type I endoleaks in HNA patients.

Comparison of computed tomography and duplex imaging in assessing aortic morphology following endovascular aneurysm repair

BACKGROUND

Computed tomography (CT) has been used to assess patients following endovascular aneurysm repair to determine the need for secondary endoluminal or operative procedures. This prospective study compared CT and duplex imaging to evaluate aneurysm morphology following endoluminal aortic grafting.

METHODS

Twenty patients were evaluated at regular intervals following successful endoluminal aneurysm repair. CT and duplex scanning were compared in their ability to determine aneurysm and aortic diameter, the presence of perigraft extravasation (endoleaks) and technical defects in the endograft.

RESULTS

In 20 patients who were assessed 6 months after operation, duplex imaging identified four endoleaks (two early, two late; one proximal, three distal). In three cases, the aneurysm diameter progressively increased after operation. In patients with a thrombosed aneurysm sac, the aneurysm regressed at a median of 0.40 (range 0.13-0.8) cm per year. The CT findings were similar (median regression 0.43 (range 0-1.0) cm per year), although CT was unable to predict the site of the leak as accurately as duplex imaging. CT demonstrated that the diameter of the juxtarenal aorta increased following endografting.

CONCLUSION

Duplex imaging is a less invasive, less costly alternative to CT in the follow-up of patients after endoluminal aortic surgery. Increase in size of the aneurysm sac following endovascular aneurysm repair strongly suggests the presence of an endoleak.

Chronic critical leg ischaemia must be redefined

The Second European Consensus Document on Chronic Critical Leg Ischaemia defines critical limb ischaemia in non-diabetic patients as rest pain or tissue necrosis (ulceration or gangrene) with an ankle systolic pressure (ASP) of less than or equal to 50 mmHg, or a toe pressure of less than or equal to 30 mmHg. The aim of this study was to investigate whether this definition is able to predict the outcome of patients with severe lower limb ischaemia and thus to determine the relevance of the definition in clinical practice. We have analysed 148 severely ischaemic limbs in 133 non-diabetic patients who presented with rest pain, tissue necrosis or a combination of these symptoms. Fifty-one percent of these limbs fulfilled the current definition with an ASP < or = 50 mmHg; 49% had an ASP > 50 mmHg and were thus not defined as critically ischaemic according to the current definition. We have compared actuarial limb salvage and mortality rates in patients with an ASP < or = 50 mmHg to those patients with an ASP > 50 mmHg. The 1 year limb salvage and mortality rates for ischaemic limbs fulfilling the European Consensus Document criteria were 78.7 and 36.7% respectively, compared to rates of 73.9 and 17.3% in patients who were not defined as critically ischaemic under the current definition. There were no significant differences between 1 year limb salvage or mortality rates between the two patients groups (p = 0.843, 0.078, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Microembolization during endovascular and conventional aneurysm repair

PURPOSE

Endovascular aneurysm repair has been advocated as a "minimally invasive" alternative to conventional aneurysm surgery. However, because of manipulation within the aneurysm sac, endovascular techniques may result in massive microembolization.

METHODS

In this study lower limb microemboli were quantified in 29 patients undergoing conventional (11 straight and 7 bifurcated grafts) and endovascular aneurysm repair (8 aortoiliac, 1 straight, and 2 bifurcated grafts) by insonation of the superficial femoral artery with a 2 MHz Doppler probe. Emboli were detected as high-intensity, short-duration signals on the background Doppler trace. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length (emboli velocity x duration = sample volume length) for each embolus (N = 4927). Previous experiments had determined that a sample volume length < 1.4 cm represented particulate embolization.

RESULTS

The number of gaseous, particulate, and total emboli were significantly greater in the endovascular group compared with the conventional group (p < 0.05).

CONCLUSIONS

These data demonstrate that peripheral microembolization is significantly higher during endovascular aneurysm repair than during conventional surgery. Methods to reduce embolization must be developed before endovascular aortic surgery is widely adopted.

Percutaneous transluminal angioplasty for lower-limb critical ischaemia

Percutaneous transluminal angioplasty (PTA) alone was used to treat 54 (23 per cent) of 232 lower limbs with critical ischaemia. Technical success was achieved in 49 cases (91 per cent) with an immediate symptomatic improvement in 47 (87 per cent). There was no death or limb loss attributable to PTA and three embolic complications were successfully treated by percutaneous aspiration. Symptomatic improvement and haemodynamic patency rates at 24 months were 77 and 78 per cent respectively; 27 of 34 limbs with ulceration or gangrene had healed with minor surgery by a median of 7.5 (range 3.0-18.0) months. Patient survival and limb salvage rates at the same time interval were 76 and 89 per cent respectively. These results demonstrate that, for a selected group of patients with lower-limb critical ischaemia, PTA can be a highly successful therapeutic option with a low associated morbidity.

Oxygen free radical and cytokine generation during endovascular and conventional aneurysm repair

OBJECTIVES

Endovascular aneurysm repair has been proposed as a "minimally invasive" alternative to conventional aneurysm resection. One of the most important potential benefits of endoluminal surgery is the avoidance of aortic cross clamping, which may attenuate the ischaemia-reperfusion injury that complicates open aneurysm repair. This study aimed to quantify the metabolic response to both conventional and endovascular aortic surgery.

DESIGN

Prospective clinical study.

SETTING

University hospital.

METHODS

Femoral vein blood samples (pre-clamp, during aneurysm repair and 5 and 30 min post reperfusion) were obtained from 12 patients undergoing aortoaortic aneurysm repair, six by conventional transperitoneal inlay replacement (median age 71 years, median aneurysm diameter 5.8 cm), and six by endoluminal deployment of a straight endograft (median age 73 years, median aneurysm diameter 5.5 cm). All endovascular procedures were completed satisfactorily with no conversions to conventional surgery.

OUTCOME MEASURES

Venous blood samples were analysed for oxygen free radical (OFR) production using the quantifiable oxidation of IgG in plasma, and cytokine (IL-1 beta and TNF-alpha) generation by radioimmunoassay. [table: see text]

RESULTS

The results are given as median values with interquartile ranges:

CONCLUSIONS

These results suggest that the ischaemia-reperfusion response associated with conventional aneurysm surgery may be largely negated by endovascular techniques. This may have significant consequences as the generation of oxygen free radicals and cytokines have been implicated in the development of systemic organ failure following aortic surgery.

Endovascular treatment of ruptured and symptomatic abdominal aortic aneurysms

OBJECTIVE

To report the experience of endovascular repair (ER) in patients with ruptured and symptomatic abdominal aortic aneurysms (rAAA and sAAA), comparing results with a cohort of controls who underwent open repair (OR) of sAAA or rAAA.

DESIGN

A historically controlled cohort study.

MATERIALS

Retrospective data from 21 patients who underwent ER and prospective data from 23 patients who underwent OR.

METHODS

Results were compared using the Mann-Whitney U-test.

RESULTS

Eleven ER patients had sAAAs and 10 had rAAAs. Nine OR patients had rAAAs and 13 had sAAAs. Thirty-day mortality was 11% in patients with rAAA in the ER group, and 54% in the OR group (p=0.03). There were no post-operative deaths in the patients who had an sAAA in the ER group, and one death in the patients who had sAAA in the OR group. Results as expressed as mean ER value versus mean OR value and p-value. ER was associated with significant reductions in the length of operation (2.6 versus 3.1h, p=0.03), blood transfusion requirements (0.86 versus 10.7 units p<0.01), time in critical care (1.5 versus 6.1 days, p=0.02), and total hospital stay (8.5 versus 17.5 days, p=0.01) compared with OR. There was no difference in time from admission to arrival in theatre between the two groups (3.4 versus 5.0h, p=0.35).

CONCLUSIONS

In patients with rAAA and sAAA that are suitable for stenting, ER has reduced mortality compared with open repair. Assessment for ER does not cause a pre-operative delay, operating time is reduced, blood transfusion requirements are reduced and there is a faster recovery.

Surgical management of 671 abdominal aortic aneurysms: a 13 year review from a single centre

OBJECTIVE

To audit the results for abdominal aortic aneurysm (AAA) repair from a single centre over a 13 year period.

DESIGN

Retrospective survey.

SETTING

Vascular unit of a major teaching hospital.

MATERIALS

Six hundred and seventy-one consecutive patients divided into two groups: group A (1981-87) and group B (1988-93).

CHIEF OUTCOME MEASURES

Mortality rates, cause of death and major complications in patients undergoing elective, urgent and ruptured AAAs.

RESULTS

Elective repair was performed in 313 (47%) patients, urgent repair in 80 (12%) and emergency repair for rupture in 278 (41%). A vascular surgeon performed the procedure in 94% of patients. The overall mortality was 21 patients in the elective group (6.7%), 13 in the urgent group (16%) and 148 in the ruptured group (53%). Mortality rates have not fallen during the study period but more patients in group B had ischaemic heart disease. Sixty patients (9%) required further operative procedures on 66 occasions: 24 elective cases (8%), 8 urgent cases (10%) and 28 ruptured cases (10%). There were 23 deaths in these 60 patients (38%) who underwent re-operation (5 elective, 2 urgent and 16 ruptured). Major postoperative complications included cardiac events in 212 (32%) patients, respiratory failure in 202 (30%) and renal failure in 90 (13%). Major causes of death included cardiac disease in 67 patients (37%), cardiac disease with coagulopathy in 22 (12%) and cardiac disease with respiratory failure in 16 (9%). Logistic regression analysis showed that in the elective group, cardiac or renal failure were significantly associated with death; and in the ruptured group cardiac, respiratory or renal failure were significantly associated with death.

CONCLUSIONS

More high risk patients with ischaemic heart disease are undergoing AAA repair. Postoperative cardiac, respiratory or renal failure are significant causes of death in AAA patients.

Prosthetic patch infection after carotid endarterectomy

OBJECTIVES AND DESIGN

prospective audit of the management and outcome of prosthetic patch infection after carotid endarterectomy (CEA) at Leicester Royal Infirmary plus review of the literature.

RESULTS

8/936 CEA patients (0.85%) developed a prosthetic patch infection. Responsible organisms included MRSA (n=3), Staphylococcus epidermidis(n=2), haemolytic Streptococcus (n=1), Staphylococcus aureus(n=1) and Pseudomonas (n=1). Early wound complications preceded 4/5 infections presenting within 9 weeks of surgery. In addition to systemic antibiotics and debridement, management included patch removal and: (i) carotid ligation (n=3), vein patch repair (n=1), vein bypass (n=3). One patient had antibiotic irrigation of the in-situpatch. No patient died, one suffered a disabling postoperative stroke and two had temporary cranial nerve injuries. Including this series, a literature review identified 43 prosthetic patch infections, 91% culturing Staphylococci or Streptococci. Cumulative freedom from perioperative stroke/death or re-infection was 65% at 2 years. Patients treated by patch excision and autologous venous reconstruction had the best outcome with a cumulative freedom from perioperative stroke/death or re-infection of 91% at 2 years.

CONCLUSION

prosthetic patch infection after CEA is rare. This study emphasises the importance of close surveillance of early wound complications. Surgical decision-making, especially the safety of carotid ligation, was facilitated by access to transcranial Doppler.

The Genetic Basis of Abdominal Aortic Aneurysms: A Review

INTRODUCTION

The pathogenesis of abdominal aortic aneurysm (AAA) remains poorly understood, however significant evidence has emerged in recent years to suggest a chronic inflammatory process. Observational studies have highlighted a familial trend towards AAA development among relatives of affected individuals and it is thought that inflammatory genes may influence an individual's susceptibility. Conflicting reports exist over single gene versus multiple gene inheritance patterns in addition to a collection of studies examining individual inflammatory genes. This paper reviews the evidence for a genetic predisposition to aneurysm formation including familial and segregation studies in addition to experimental evidence investigating specific candidate genes.

METHOD

Medline and Pubmed database searches were conducted using the search terms abdominal aortic aneurysm and gene. Papers were reviewed and references manually searched for further relevant publications which were added to the data. Papers were categorised under the headings familial, segregation and candidate gene studies.

RESULTS

A review of 58 papers is presented under sub-headings as above. In the case of the candidate gene section, a brief report of the functional relevance of each gene is included.

CONCLUSION

A summary of the evidence presented is given and the direction of future work in this field is briefly considered.