Long-term follow-up of fenestrated endovascular repair for juxtarenal aortic aneurysm

BACKGROUND

Fenestrated endovascular aneurysm repair (FEVAR) is increasingly being used for juxtarenal aortic aneurysms. The aim of this study was to review long-term results and assess the importance of changing stent-graft design on outcomes.

METHODS

This was a retrospective review of all patients who underwent FEVAR within a single unit over 12 years (February 2003 to December 2015). Kaplan-Meier analysis of survival, and freedom from target vessel loss, aneurysm expansion, graft-related endoleak and secondary intervention was performed. Comparison between outcomes of less complex grafts (fewer than 3 fenestrations) and more complex grafts (3 or 4 fenestrations) was undertaken.

RESULTS

Some 173 patients underwent FEVAR; median age was 76 (i.q.r. 70-79) years and 90·2 per cent were men. Median aneurysm diameter was 63 (59-71) mm and median follow-up was 34 (16-50) months. The adjusted primary technical operative success rate was 95·4 per cent. The in-hospital mortality rate was 5·2 per cent; there was no known aneurysm-related death during follow-up. Median survival was 7·1 (95 per cent c.i. 5·2 to 8·1) years and overall survival was 60·1 per cent (104 of 173). There was a trend towards an increasing number of fenestrations in the graft design over time. In-hospital mortality appeared higher when more complex stent-grafts were used (8 versus 2 per cent for stent-grafts with 3-4 versus fewer than 3 fenestrations; P = 0·059). Graft-related endoleaks were more common following deployment of stent-grafts with three or four fenestrations (12 of 90 versus 6 of 83; P < 0·001).

CONCLUSION

Fenestrated endovascular aneurysm repair for juxtarenal aneurysm is associated with few aneurysm-related deaths in the long term. Significant numbers of secondary interventions are required, but the majority of these can be performed using an endovascular approach.

Neuromuscular electrical stimulation for thromboprophylaxis: A systematic review

OBJECTIVE

To evaluate the effect of neuromuscular electrical stimulation on lower limb venous blood flow and its role in thromboprophylaxis.

METHOD

Systematic review of randomised and non-randomised studies evaluating neuromuscular electrical stimulation, and reporting one or more of the following outcomes: incidence of venous thromboembolism, venous blood flow and discomfort profile.

RESULTS

Twenty-one articles were identified. Review of these articles showed that neuromuscular electrical stimulation increases venous blood flow and is generally associated with an acceptable tolerability, potentially leading to good patient compliance. Ten comparative studies reported DVT incidence, ranging from 2% to 50% with neuromuscular electrical stimulation and 6% to 47.1% in controls. There were significant differences, among included studies, in terms of patient population, neuromuscular electrical stimulation delivery, diagnosis of venous thromboembolism and blood flow measurements.

CONCLUSION

Neuromuscular electrical stimulation increases venous blood flow and is well tolerated, but current evidence does not support a role for neuromuscular electrical stimulation in thromboprophylaxis. Randomised controlled trials are required to investigate the clinical utility of neuromuscular electrical stimulation in this setting.

How secure is the anastomosis between the proximal and distal body components of a fenestrated stent-graft?

OBJECTIVES

To examine the longitudinal migratory force required to cause disconnection of the bifurcated distal body component from the tubular proximal body of a fenestrated stent-graft.

METHODS

Using a previously reported mathematical model distal distraction forces were calculated prior to performing in vitro pullout testing. The top end of the proximal body and the iliac limbs of the distal body were attached to the grips of a tensile tester via plastic sealing plugs and pneumatic clamps. Channels within the plugs allowed pressurisation of the inside of the stent-graft. Pullout tests were conducted in the vertical plane. Force and displacement data were recorded and tests repeated 8 times at room temperature with the stent-grafts either dry or wet and unpressurized, at 100 mmHg or at 120 mmHg.

RESULTS

The median maximum pullout force was 2.9 N (2.6-4.1) when dry, 3.9 N (3.5-5.4) when wet and unpressurized, 6.3 N (4.8-8.3) when wet and pressurized at 100 mmHg and 6.5 N (4.8-7.2) when wet and pressurized at 120 mmHg. There was a significant difference between pressurized and unpressurized conditions (P < 0.01).

CONCLUSIONS

The force required to distract the distal bifurcated component of a fenestrated stent graft is much lower than the reported proximal fixation strength of both a standard and fenestrated Zenith stent graft. Although this helps protect the fenestrated proximal body from the effects of longitudinal migration forces in vivo the current strength of the body overlap zone may actually be unnecessarily weak and requires careful surveillance in follow up.

Deficiencies in venous experience in UK vascular trainees: a survey of Rouleaux Club members

Objective

The aim of this study was to evaluate the training experience of current UK vascular trainees in the modern management of venous disease.

Method

A web-based questionnaire of the 145 members of the Rouleaux Club (www.rouleauxclub.com), which represents UK vascular trainees. Members were asked to complete the survey between June and October 2009 with regular email reminders being sent out to non-responders.

Results

One hundred and twenty-three trainees (85% response rate) representing all 17 UK training Deaneries responded. Seventy-eight per cent reported having received no formal venous duplex training either for diagnosis of venous disease or to guide endovenous therapy. Operative experience of great and small saphenous vein surgery improved with years of training. Surgical experience for recurrent varicose veins was poor. Experience with endovenous techniques was limited and variable. No experience of endovenous laser ablation or radiofrequency ablation was reported by 39% and 67% of trainees, respectively. Experience and/or training with foam sclerotherapy was limited to <40%. Many of those reporting no experience with endovenous ablation techniques were within the final two years of their training. Less than 25% of trainees reported having had any experience (assisted/performed) of advanced venous interventions such as thrombolysis techniques for deep venous thrombosis, inferior vena cava filter placement/removal, venous stenting or deep venous reconstruction. Less than a quarter of trainees are currently involved in the acute management of deep venous thrombosis. The majority (76%) of current trainees would like a formal approved UK venous training course to be offered.

Conclusion

The current level of training in the management of venous disease will not allow UK vascular trainees to become the competent all round vascular specialists of the future.

Traveller's thrombosis: airlines still not giving passengers the WRIGHT advice!

INTRODUCTION

This study has examined the impact of the World Health Organization's Research into Global Hazards of Travel (WRIGHT) Project's phase 1 report on the information given by airlines to their passengers regarding traveller's thrombosis.

METHODS

Official websites of all airlines flying from Heathrow (UK) and John F Kennedy (USA) were located through links on the websites of these two busy international airports. In June 2007, each site was scrutinized by three independent researchers to identify if traveller's thrombosis and its risk factors were discussed and what methods of prevention were advised. This exercise was repeated a year after the publication of the WRIGHT report.

RESULTS

One hundred and nineteen international airlines were listed in 2007 (12 were excluded from analysis). A quarter (27/107) of airlines warned of the risk of traveller's thrombosis. A year later, five airlines were no longer operational and there had been no increase in the discussion of traveller's thrombosis (23/102). Additional risk factors discussed in June 2007 versus September 2008: previous venous thromboembolism (16%, 15%); thrombophilia (14%, 15%); family history (11%, 9%); malignancy (12%, 14%); recent surgery (19%, 16%); pregnancy (17%, 16%) and obesity (11%, 12%). Prophylaxis advice given in June 2007 versus September 2008: in-flight exercise (34%, 42%); Hydration (30%, 34%); medical consultation prior to flying (20%, 18%); graduated compression stockings (13%, 12%); aspirin (<1%, <1%) and heparin (5%, 7%).

CONCLUSIONS

The majority of world airlines continue to fail to warn of the risk of traveller's thrombosis or offer appropriate advice. Alerting passengers at risk gives them an opportunity to seek medical advice before flying.

Wholly endovascular repair of thoracoabdominal aneurysm

Background

The aim was to evaluate a wholly endovascular approach to the repair of thoracoabdominal aortic aneurysm (TAAA).

Methods

Six patients (median age 71 years) underwent wholly endovascular repair of TAAA (maximum diameter 56–85 mm) employing individually customized endografts. Procedures were performed under general anaesthesia, with spinal drainage in five patients. Patients were followed by serial computed tomography, plain radiography and duplex imaging for a median of 17 (range 8–44) months.

Results

All grafts were deployed as intended, with preservation of all target vessels. There were no postoperative deaths, strokes or paraplegia. One patient suffered a silent myocardial infarction. In two patients a persistent paraostial endoleak was treated by further balloon dilatation of the stent within the endograft fenestration. Imaging before discharge confirmed aneurysm exclusion in all patients. Two patients required late secondary intervention to abolish endoleaks due to side-branch disconnection. One patient suffered late occlusion of the coeliac axis without clinical sequelae, and late occlusion of a solitary renal artery in another resulted in dependence on dialysis. There have been no late deaths and all aneurysms remain excluded.

Conclusion

Wholly endovascular TAAA repair is relatively safe, but long-term follow-up is required to establish its durability.

Is failure to provide venous thromboprophylaxis negligent?

OBJECTIVES

To report the outcome of 100 consecutive medicolegal claims referred to one of the authors (1990-2003) following the development of venous thromboembolism (VTE) in surgical patients.

METHODS

A retrospective analysis of the experience of a vascular surgeon acting as an expert witness in the United Kingdom.

RESULTS

Prophylaxis had been provided to 43 claimants with risk factors, who, unfortunately, still developed a VTE and alleged negligence. Twenty-nine claims involved patients who had not received prophylaxis because they were at low risk. In 25/28 claims where no prophylaxis was provided, despite identifiable VTE risk factors, the claim was successful. Claimants who developed a VTE that had been managed incorrectly were successful whether they had received prophylaxis or not. Settlement amounts, where disclosed, are reported.

CONCLUSIONS

Failure to perform a risk assessment and to provide appropriate venous thromboprophylaxis in surgical patients is considered negligent. Clinicians looking after all hospitalized patients who are not assessing their patients' risk for VTE and/or not providing appropriate prophylaxis are at risk of being accused of negligence.

Fenestrated endovascular repair for juxtarenal aortic aneurysm

Background

The outcome of fenestrated endovascular aneurysm repair (F-EVAR) was evaluated.

Methods

Between February 2003 and December 2006, 45 patients (median age 73 (range 53–85) years) underwent primary (41) or secondary (four) F-EVAR for an abdominal aortic aneurysm with infrarenal neck anatomy unsuitable for a standard stent-graft. Median aneurysm diameter was 68 (range 55–100) mm and median infrarenal aortic neck length was 6 (range 0–13) mm. Customized fenestrated Zenith® stent-grafts were employed in all procedures, incorporating fenestrations to preserve flow into renal (80), superior mesenteric (35) and coeliac (two) arteries. Eighty-two target vessels were stented (61 bare metal, 21 covered).

Results

All aneurysms were isolated successfully, with preservation of the target vessels. One accessory renal artery was lost. One patient died after 5 days from myocardial infarction, and another at 3 months from multiorgan failure secondary to atheroembolism. At median follow-up of 24 (range 1–48) months, all aneurysms were stable or shrinking, with no late ruptures or graft-related endoleaks. Six patients required a secondary intervention. The primary vessel patency rate was 96·6 per cent. There were four late deaths, unrelated to the aneurysm.

Conclusion

F-EVAR enabled successful treatment of juxtarenal aortic aneurysm with a low complication rate.