P. R. Taylor

Endovascular Repair of Acute Uncomplicated Aortic Type B Dissection Promotes Aortic Remodelling: 1 Year Results of the ADSORB Trial

OBJECTIVES Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year. METHODS The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB. RESULTS Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062). CONCLUSIONS Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Fatal Colonic Ischaemia after Stent Graft for Aortic Aneurysm

The development of new technology has led to renewed interest among both surgeons and radiologists in the treatment of infrarenal aortic aneurysms by endovascular techniques. Parodi and Palmaz pioneered the endovascular repair of aortic aneurysms using a straight stent graft. 1 Chuter et al. developed a means of deploying a bifurcated graft via the transfemoral route 2 and other series have been reported recently. 3 However, all new techniques have a learning curve. We report a case of fatal internal iliac artery embolism associated with insertion of a stent graft used to treat a symptomatic abdominal aortic aneurysm.

GASTRIC INTRAMUCOSAL PH PREDICTS OUTCOME AFTER SURGERY FOR RUPTURED ABDOMINAL AORTIC ANEURYSM

OBJECTIVE The mortality associated with repair of ruptured abdominal aortic aneurysms (RAAA) remains obstinately high and many deaths result from multiple organ failure which is likely to be related to splanchnic ischaemia. The aim of this study is to investigate the importance of splanchnic ischaemia in determining outcome from RAAA by comparing gastric intramucosal pH with other methods of assessing the adequacy of splanchnic oxygenation. DESIGN AND SETTING Prospective cohort of patients following surgery for RAAA admitted to the Intensive Care Unit of Guys Hospital, London. OUTCOME MEASURES Gastric intramucosal pH (pHim) and global haemodynamic, oxygen transport and metabolic variables were measured on admission, at 12 h and at 24 h after admission. Results were compared between survivors and non-survivors and Receiver Operating Characteristic (ROC) curves were constructed to assess the ability of each measurement to predict outcome. RESULTS The median 24 h APACHE II was 18 and the ICU mortality 45.5%. Gastric pHim was significantly higher in survivors than non-survivors at 24 h (7.42 vs. 7.24, p < 0.01). In survivors who had a low intramucosal pH (pHim) on admission there was a significant improvement over the first 24 h (7.26 to 7.40, p < 0.05), whereas in patients who subsequently died, and had a normal pHim on admission, there was a significant fall in pHim (7.35 to 7.16, p < 0.05). ROC curves showed that gastric pHim was the most sensitive measurement for predicting outcome in these patients. CONCLUSIONS Gastric intramucosal pH is the most reliable indicator of adequacy of tissue oxygenation in patients with RAAA, suggesting that splanchnic ischaemia may have played an important role in determining survival.

The Concept of Knee Salvage: Why Does a Failed Femorocrural/pedal Arterial Bypass Not Affect the Amputation Level?

OBJECTIVES There is continued controversy over whether a failed distal bypass influences the level of amputation. This issue is important as the number of arterial bypass grafts undertaken for critical ischaemia is increasing, followed by an increasing number of failed grafts. SETTING Teaching hospital. STUDY DESIGN AND MATERIALS: A prospective analysis of 109 consecutive femorocrural/pedal bypass grafts performed between June 1991 and January 1995 on patients presenting with severe critical lower limb ischaemia (CLI) to a single vascular unit. A further 43 amputations for non-reconstructible distal disease were also analysed. CHIEF OUTCOME MEASURES Mortality, amputation, rehabilitation, survival and knee salvage rates. The Kaplan-Meier method was used for comparison of factors associated with knee preservation. RESULTS Primary amputees had a higher in-hospital mortality (18% vs. 10%) but similar 3 year survival rates (30%) compared with secondary amputees (36.6%). Patients with successful grafts showed a trend towards better survival (61.9% at 3 years) compared to amputees (38.6% at 42 months, p = 0.061). Below- to above-knee amputation ratio was similar in the two groups (0.85 in secondary vs. 0.95 in primary amputees). Factors significantly associated with knee salvage at 3 years were shown to be: the condition of the inflow (81.9% for good vs. 43.1% for impaired, p = 0.000) the state of the profunda femoris artery (good 93%, impaired 71%, occluded 37% p = 0.0001) and the graft material (vein 81.8% vs. PTFE 59.8%, p = 0.033). The presence of tissue loss (p = 0.0523) and secondary procedures (p = 0.0879) showed a trend to become significant. Multivariate and Cox regression analysis showed that the most important factors were the inflow (p = 0.001), the state of the profunda (p = 0.001), the graft material (p = 0.034) and previous revascularisation attempts (p = 0.019). CONCLUSIONS The factors which determine knee loss are a compromised inflow state, the presence of an inadequate profunda femoris, previous revascularisation attempts and the use of synthetic graft material. Most of these factors (with the exception of infection related to revascularisation) are present before reconstructive arterial surgery is performed and this study shows that failure of a distal graft does not affect the final amputation level.

Percutaneous angioplasty for infrainguinal graft-related stenoses

OBJECTIVE To assess the success of percutaneous transluminal angioplasty (PTA) in treating infrainguinal graft-related stenoses. DESIGN Retrospective analysis of stenoses undergoing PTA over 6 years. MATERIALS Fifty-seven stenoses in 42 grafts. METHODS Site, length and type of stenoses recorded. Follow-up till discharge, graft occlusion or death. RESULTS PTA was successful in 48/57 stenoses in 36 grafts (G), with a poor result in seven. Further PTA was required in seven stenoses (7 G). One graft occluded at PTA and one stenosis was inaccessible. Overall graft (G) patency (median 13 months) was 82% (1 year patency 84%). Of 48 successful PTAs (37 G), 36 remained patent (28 G), eight (4 G) occluded and four were lost to follow-up (4 G). Fourteen of thirty-six stenoses which remained patent required further intervention (seven PTA, six jump grafts, one vein patch). The four occlusions were associated with small veins (two), multiple stenoses (one) and a PTFE graft which occluded 10 days following PTA. Of the seven PTAs with a poor angiographic result, five remained patent, three after further intervention. CONCLUSION PTA is the best treatment for localised stenoses. Stenoses > 2 cm or multiple (three or more) stenoses are best treated surgically. Follow-up is essential, as 20% require further intervention.

Endovascular repair of residual iliac artery aneurysms following surgery for ruptured abdominal aortic aneurysm.

Emergency repair of ruptured abdominal aortic aneurysm continues to have a high mortality. Such patients require expeditious operations to repair the ruptured segment rather than attempts to deal with all coexisting disease. The use of endovascular techniques obviates the need for open surgery to repair iliac aneurysms. We report two patients who, after successful repair of ruptured abdominal aortic aneurysms, had three iliac artery aneurysms treated successfully by embolisation in one case and percutaneous insertion of a self expandable stent graft in two cases. The issues that arise from such an approach are discussed with a review of the literature.

Recurrent coronary-subclavian steal syndrome treated by left subclavian artery stenting

The left internal mammary artery (LIMA) has better long-term patency rates than long saphenous vein grafts when used for coronary artery bypass surgery. 1 However, blood flow through it can be compromised by proximal disease in the left subclavian artery, resulting in recurrence of the symptoms of myocardial ischaemia. This has been termed the coronary-subclavian steal syndrome, and retrograde flow through the LIMA graft can be shown on coronary angiography. Various treatments have been used to correct this, including carotid-subclavian bypass, percutaneous transluminal angioplasty (PTA) and most recently, primary stenting. We describe a case initially treated with angioplasty, which recurred and eventually required percutaneous stenting with complete resolution of symptoms.

The results of routine primary closure in carotid endarterectomy.

PURPOSE OF STUDY The aims of this study were to determine the incidence of restenosis following carotid endarterectomy with primary closure of the arteriotomy and to observe the natural history of disease progression in the 1st postoperative year. METHODS The study group consisted of a consecutive series of 126 patients undergoing carotid endarterectomy. Duplex imaging was performed preoperatively and at 8 weeks, 6 months and 1 year postoperatively. RESULTS Five patients (4%) had a residual stenosis. At 12 months, the overall restenosis rate was 15%: 8.5% for males and 28.9% for females. None of these restenoses were symptomatic. There was no significant difference in the diameter of the internal carotid artery between male and female patients (U = 896, P = 0.60) and no significant difference in the diameter of the arteries that had restenosed at 12 months and those that had remained patent (U = 391, P = 0.33). CONCLUSIONS Carotid endarterectomy with primary closure is associated with a low incidence of restenosis in men, but not in women. Criteria for selective patching should consider both gender and vessel calibre.

Use of through-and-through guidewire for delivering large stent-grafts into the distal aortic arch

The availability of large diameter stent-grafts is now allowing the endovascular treatment of thoracic aortic aneurysms. Most aneurysms are closely related to the distal arch and it is thus necessary to pass the delivery systems into the arch to effectively cover the proximal neck. Even with extra-stiff guidewires in position, it may still be difficult to achieve this, as a result of tortuosity at the iliac arteries and the aorta. We detail a technique where a stiff guidewire is passed from a brachial entry point through the aorta and out at the femoral arteriotomy site. This allows extra-support and may enable the delivery system to be passed further into the aortic arch than it could with just the regular guidewire position.

A PAPER FOR DEBATE : VEIN VERSUS PTFE FOR CRITICAL LIMB ISCHAEMIA : AN UNFAIR COMPARISON?

INTRODUCTION There is a widely held view that vein grafts for infrainguinal arterial reconstruction perform much better than prosthetic conduits, the best of which seems to be PTFE. Many randomised studies have been conducted which confirm this opinion, but is the difference as large as it is thought to be? One interesting feature of published trials is that the results for obligatory PTFE (when no vein is available) were much worse than the results for randomised PTFE grafts. The only way to explain this is that these groups of patients were not similar, and there are probably other factors which contribute to the difference in results when vein and PTFE grafts are compared. MATERIALS AND METHODS A consecutive series of 109 femoro-infrapopliteal grafts undertaken for critical limb ischaemia was analysed to see the difference between vein and PTFE with vein cuff grafts. RESULTS Vein grafts were superior to PTFE grafts when the whole cohort was included (p = 0.0038); however, there was no significant difference when the patients were stratified for inflow and runoff status. CONCLUSIONS The difference between vein and PTFE has probably been exaggerated in the past, due to differences in risk factors and in the extent of arterial disease between the two groups of patients. The advantage of vein becomes more significant with time.