The EVAR Trial 1: has it led to a change in practice?

OBJECTIVES: To assess whether the publication of the EVAR Trial 1 (June 2005) had an impact on practice in our centre. METHODS: A retrospective study of all patients undergoing abdominal aortic aneurysm (AAA) repair in Leicester, from the year before publication of EVAR Trial 1 data to the year after (July 2004 - June 2006). Data from the study period was then compared with practice over the last six years (January 2000 - December 2006). RESULTS: The proportion of endovascular aneurysm repairs (EVARs) did not change significantly in the year following publication of EVAR Trial 1 data (52% VS 57%, p=0.64). The mean age of patients offered open repair (OR) fell in the year following publication (69 years +/- 6.68 vs 72 years +/- 5.71, p<0.05). Despite this, there was no significant change in their fitness (physiological POSSUM scores: 19.2 +/- 3.91 vs 18.2 +/- 3.74, P=0.30). There was an overall increase in the percentage of EVARs in the years 2000 (28%) to 2006 (57%). CONCLUSION: There was no significant difference in the percentage of EVARs between the two years of study. However, over the last six years, there has been an increasing number performed in our unit and we now do more EVARs than ORs.

Endovascular abdominal aortic aneurysm repair: 5-year follow-up results.

Endovascular aneurysm repair (EVAR) offers a minimally invasive alternative to open repair and has the benefits of reduced perioperative morbidity and mortality. There are potential complications specific to EVAR, including device failure, graft migration, and endoleak, which necessitate long-term follow-up. This remains a relatively novel technique, and therefore, little long-term data exist. This study reports 5-year EVAR outcome data from a single center. Five-year follow-up data for 58 patients at a single center who underwent EVAR using a variety of different commercial devices was reviewed. All patients were followed up with 6-monthly duplex ultrasound scanning and clinical assessment in a nurse-led clinic, in addition to yearly computed tomographic (CT) scans for those participating in the EVAR trial. All patients in this series were male, with a median age of 72 years (range 58-81). Mean preoperative aortic diameter was 5.95 cm, and this reduced following EVAR to 5.2 cm (mean diameter) at 5 years. Mean hospital stay was 7 days, and there were no perioperative deaths. There were 20 (34%) early and 15 (26%) late complications. There were 13 endoleaks confirmed on CT; four (31%) were type I and nine (69%) were type II. All-cause mortality was 26%. There were no late aneurysm-related deaths. EVAR has the advantages of shorter hospital stay and reduced perioperative morbidity and mortality. Long-term follow-up remains a priority following aortic stenting in order to detect late complications such as endoleak.

Endovascular abdominal aortic aneurysm repair.

The operative mortality following conventional abdominal aortic aneurysm (AAA) repair has not fallen significantly over the past two decades. Since its inception in 1991, endovascular aneurysm repair (EVAR) has provided an alternative to open AAA repair and perhaps an opportunity to improve operative mortality. Two recent large randomised trials have demonstrated the short and medium term benefit of EVAR over open AAA repair, although data on the long term efficacy of the technique are still lacking. This review aimed at providing an overview of EVAR and a discussion of the potential benefits and current limitations of the technique.

The occurrence of arterio-venous fistula during lower limb subintimal angioplasty: treatment and outcome.

OBJECTIVES: To describe our experience with iatrogenic arterio-venous fistula (AVF) occurring during lower limb subintimal angioplasty, their management and the final clinical, radiological outcome. DESIGN: Retrospective review of case series from two centres, from a computerised database over a period of five years. MATERIAL: Twelve patients whose lower limb subintimal angioplasty was complicated by Iatrogenic AVF. RESULTS: The Majority of AVF occurred at the popliteal trifurcation vessels. And the incidence of this complication in our case series was 0.8%. This was managed with a variety of techniques-Coil embolisation, balloon tamponade, alternative dissection and stent placement. In one patient, the fistula was left open intentionally. All twelve patients had a successful angioplasty. The overall technical success rate for AVF ablation was eighty percent. CONCLUSIONS: AVF is a potential complication of angioplasty. The majority can be managed by endovascular means during the angioplasty procedure with good technical success.

Factors affecting patency of subintimal infrainguinal angioplasty in patients with critical lower limb ischemia.

BACKGROUND: Because subintimal angioplasty (SA) is a technique that can achieve recanalization of long arterial occlusions, it is considered an alternative to lower limb bypass operations. The aim of this prospective study was to identify the risk factors that affect patency of SA in patients suffering from critical limb ischemia (CLI). METHODS AND RESULTS: 51 consecutive infrainguinal SA were done in 46 patients suffered from CLI. The patients were followed-up with regular duplex scans up to 12 months post-intervention. Sex, atherosclerosis risk factors, and some technical details of the procedure (number of patent run-off vessels after the procedure, length and re-entry point of angioplasty) were examined as potential risk factors of patency, using survival analysis statistical techniques. The overall patency rate at 12 months post-intervention was 50%. According to Cox-regression analysis, the factors that affect patency were the number of run-off vessels and the length of occlusion. Patients with two or three run-off vessels had a hazard of occlusion of 0.30 (P = .027) compared to those who had one run-off vessel. The 12-months patency in patients with more than one run-off vessels was 81% vs. 25% in patients with one run-off vessel. Regarding the length of angioplasty, the hazard of reocclusion was 1.02 for every centimeter of occlusion (P = .049). CONCLUSIONS: The number of patent run-off crural vessels after the angioplasty and the length of occlusion are significant risk factors for reocclusion of infrainguinal SA in patients with CLI. Trying to recanalize more than one run-off vessels could raise the SA patency.

Duplex ultrasound scanning is reliable in the detection of endoleak following endovascular aneurysm repair.

OBJECTIVE: To investigate the value of duplex ultrasound scanning (DUSS) in the routine follow up of patients following EVAR. METHODS: Imaging was reviewed for 310 consecutive patients undergoing EVAR at a single centre. Concurrent ultrasound and CT scans were defined as having occurred within 6 months of each other. There were 244 paired concurrent DUSS and CT scans which were used for further analysis. These modalities were compared with respect to sensitivity, specificity, positive and negative predictive values and level of agreement (by Kappa statistics) using CT as the 'gold standard'. RESULTS: DUSS failed to detect a number of endoleaks which were seen on CT and the sensitivity of this test was therefore poor (67%). However, the specificity of DUSS compared more favourably with a value of 91%. Positive predictive values ranged from 33-100% but negative predictive values were more reliable with values of 91-100% at all time points post operatively. There were no type I leaks, or endoleaks requiring intervention which were missed on DUSS. Overall, there was a 'fair' level of agreement between the two imaging modalities using Kappa statistics. CONCLUSION: Although DUSS is not as sensitive as CT scanning in the detection of endoleak, no leaks requiring intervention were missed on DUSS in this study. DUSS is much cheaper than CT and avoids high doses of radiation. DUSS therefore remains a valuable method of follow up after EVAR and can reduce the need for repeated CT scans.

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.

Cerebral protection during open retrograde angioplasty/stenting of common carotid and innominate artery stenoses.

BACKGROUND: This was a retrospective study of the effectiveness of open, retrograde angioplasty/stenting of supra-aortic arterial stenoses combined with transcranial Doppler-directed dextran therapy in preventing perioperative embolization. METHODS: Eight patients underwent angioplasty/stenting of the proximal common carotid (synchronous carotid endarterectomy (CEA) in six), while four underwent angioplasty/stenting of the innominate artery (synchronous CEA in one). Open exposure of the carotid bifurcation enabled temporary carotid clamping to protect the brain from procedural embolization. Dextran was administered to patients with a high rate of embolization on transcranial Doppler after the operation. RESULTS: No emboli were recorded in the cerebral circulation during the actual angioplasty procedure when the internal carotid artery was clamped. After operation three patients developed high-rate embolization and received dextran. No strokes or deaths occurred within 30 days of treatment. One patient developed symptoms and a recurrent stenosis greater than 50 per cent during follow-up and was treated by redo angioplasty. CONCLUSION: Retrograde angioplasty/stenting with or without synchronous CEA offers an alternative approach to treating patients with supra-aortic inflow disease.

Endotension--a late complication successfully treated by open repair.

Endotension is a late complication following endovascular treatment of abdominal aortic aneurysm (AAA). A 83-year-old male had a successful endovascular repair of a 5.6 cm diameter AAA. During the follow-up period it was marked that the aneurysm continued to increase in size, became 6.6 cm maximal diameter and pulsatile with no evidence of endoleak. On laparotomy no endoleak was identified and the graft was left in situ. Postoperatively and on follow-up the patient remains asymptomatic while the aneurysm continued to appear shrunk.

The post-operative complications of endovascular aortic aneurysm repair.

Endovascular abdominal aortic aneurysm repair (EVAR) was first described in 1991. It has now been established as a technically feasible and successful procedure in the short-term and may be a viable long-term alternative to open aortic aneurysm repair. However, EVAR is associated with a significant risk of complication in terms of both procedural associated morbidity and operative mortality. These complications have important implications since if EVAR is to replace open aneurysm repair in the future it must be associated with equivalent or preferably better peri-operative mortality and long-term outcome. This paper reviews the current published data regarding the nature, incidence and implications of the complications of EVAR.

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.

Techniques for the endovascular management of complications following lower limb percutaneous transluminal angioplasty.

OBJECTIVES: to determine the incidence of early complications following percutaneous transluminal angioplasty and to describe their management and outcome. MATERIALS: five hundred and fifty consecutive patients undergoing angioplasty of 648 limbs, containing 1053 anatomical segments during a two year period were reviewed retrospectively. RESULTS: early complications affected 109 segments (10%) in 92 limbs (14%) of 84 patients (15%). Of the 109 segments affected by early complications, 106 (97%) were managed by endovascular techniques with surgery being required on only three (3%) occasions. There were no deaths attributable to angioplasty. CONCLUSIONS: although early complications occur in 14% of limbs undergoing percutaneous transfemoral angioplasty, the majority (97%) can be managed by endovascular techniques.

Endovascular repair of wide neck AAA--preliminary report on feasibility and complications.

AIM: To assess the feasibility of endovascular repair (EVR) of wide neck abdominal aortic aneurysms (AAA). STUDY DESIGN: Retrospective. METHOD: A cohort of patient was identified who had an AAA neck diameter of 28 mm or more and underwent EVR. These patients undergo regular follow-up by 6 monthly CT scan of abdominal aorta. Two independent observers quantified the diameter of the suprarenal aorta, the top of the neck, the bottom of the neck, the length of the neck and the transverse diameter of the AAA. RESULTS: The study cohort comprised 16 patients. Bland Altman Analysis determined that the 95% interobserver limits of agreement were -4.7 to 3.3 mm. The mean preoperative diameter of the suprarenal aorta, the top of the neck and bottom of the neck all were 31 mm. On the follow-up CT scan on average after 12 months the suprarenal aorta measured 29 mm, the top of the neck 28 mm and the bottom of the neck 30 mm. There was a statistically significant decrease in the size of the top of the neck (p = 0.03). CONCLUSION: This preliminary report suggests that the endovascular repair of AAA with a wide neck is feasible with available commercial devices. The necks do not appear to increase in size and there is no increased incidence of proximal endoleak.

Complications following peripheral angioplasty.

BACKGROUND: Peripheral angioplasty is increasingly the first choice intervention in patients with peripheral vascular disease. The aim of the current study was to audit prospectively all major complications, especially the requirement for emergency surgical intervention. PATIENTS AND METHODS: A prospective audit of outcome after peripheral angioplasty in 988 patients undergoing 1377 interventional procedures between 1 October 1995 and 30 September 1998 at which 1619 vessel segments were angioplastied. RESULTS: Major medical morbidity (bronchopneumonia, stroke, renal failure, myocardial infarction) complicated 33/1377 procedures (2.4%). Emergency surgical intervention was required after 31/1377 procedures (2.3%) with the commonest aetiologies being acute limb ischaemia and haemorrhagic complications. The amputation rate following angioplasty was 0.6% and no patient presenting with claudication or graft complications underwent amputation. The amputation rate following angioplasty for critical limb ischaemia was 2.2%. Overall, the risk of death and/or major medical complication and/or requiring emergency surgical intervention was 3.5%. The rate of complications was no different for subintimal as opposed to transluminal angioplasties. CONCLUSIONS: Peripheral angioplasty is associated with a low risk of major medical and surgical complications.

The influence of relative resistance and urea-supplementation on deliberate infection with Teladorsagia circumcincta during winter.

The consequences for lambs of infection over the winter with Teladorsagia circumcincta were quantified by deliberate, trickle infection of selected animals at 7 months of age. Infected and control uninfected animals were each allocated into four groups, relatively resistant animals on a normal diet, relatively resistant animals on an isocaloric diet supplemented with urea, and relatively susceptible animals on the same two diets. Resistance and susceptibility was assessed by faecal egg counts following natural infection during the summer preceding the deliberate infection. During the deliberate infection egg counts remained low and most parasites recovered at necropsy were inhibited larvae. Nonetheless, infection reduced weight gain, decreased albumin and fructosamine concentrations and provoked a noticeable pepsinogen and eosinophil response. As most larvae were inhibited these responses may have been largely a consequence of immuno-inflammatory responses in the host rather than the direct action of parasites themselves. Relatively resistant animals on the supplemented diet allowed fewer larvae to establish and had higher fructosamine concentrations, higher albumin concentrations and decreased pepsinogen responses. Therefore, a combination of relatively resistant sheep and nutritional supplementation appears most efficient at controlling infection.

Endovascular repair of an innominate artery false aneurysm following blunt trauma.

PURPOSE: To describe a case of endovascular graft exclusion of an innominate artery pseudoaneurysm arising from blunt trauma. METHODS AND RESULTS: A 21-year-old patient was admitted following a major road accident. Computed tomography (CT) and aortography on admission disclosed an isolated innominate artery pseudoaneurysm. The lesion was stable, so an elective endoluminal repair was undertaken once the patient was treated for his other injuries. The right carotid artery was exposed and controlled, and the aneurysm was excluded by transluminal implantation of a customized stent-graft consisting of predilated polytetrafluoroethylene graft material covering a balloon-expandable Palmaz stent. A CT scan at 1 month and duplex scans at 6-month intervals documented good stent-graft positioning and aneurysm exclusion over a period of 18 months. CONCLUSIONS: This case illustrates the potential durability of endoluminal repair of innominate artery lesions and highlights the potential role of this minimally invasive alternative to surgery in these clinical situations.