Hybrid and total endovascular repair of the aortic arch.

BACKGROUND: Recent advances in endovascular technology have enabled minimally invasive repair of the aortic arch, with specifically designed stent-grafts. This article reviews hybrid and total endovascular repair in the management of aortic arch pathology. METHODS: Studies relating to aortic arch management were identified using MEDLINE and Embase, focusing on endovascular repair. RESULTS: Hybrid arch repair is associated with an early mortality rate of some 12 per cent, and carries significant risk of stroke (up to 15 per cent), paraplegia (up to 6 per cent), retrograde dissection (up to 6·5 per cent) and proximal endoleak (6 per cent). Despite patients being of overall higher perioperative risk, hybrid repair has morbidity and early mortality rates comparable to those of open arch replacement. However, rates of freedom from aortic rupture or reintervention are significantly lower in the longer term, owing to the incidence of endoleak. Total endovascular arch repair may be achieved by the use of parallel stents or in situ fenestration in the emergency setting, or use of custom-made devices (scalloped, fenestrated or branched stent-grafts) in the elective setting. Reports of these relatively novel technologies suggest acceptable short-term outcomes, but long-term data are still awaited. CONCLUSION: Repair of aortic arch pathology presents a formidable challenge for endovascular technology. Open aortic arch repair remains the standard in younger, fitter patients, but endovascular technology and experience continue to evolve with encouraging early outcomes and expanding indications.

Early outcomes of patients transferred with ruptured suprarenal aneurysm or dissection.

Objective Despite centralisation of the provision of vascular care, not all areas in England and Wales are able to offer emergency treatment for patients with acute conditions affecting the aorta proximal to the renal arteries. While cardiothoracic centres have made network arrangements to coordinate care for the repair of type A dissections, a similar plan for vascular care is lacking. This study investigates early outcomes in patients with ruptured suprarenal aortic aneurysm or dissection (rSRAD) transferred to a specialist centre. Methods Retrospective observational study over a five-year period (2009-2014) assessing outcomes of patients with ruptured sRAD diagnosed at their local hospital and then transferred to a tertiary centre capable of offering such treatment. Results Fifty-two patients (median age 73 years, 32 male) with rSRAD were transferred and a further four died during transit. The mean distance of patient transfer was 35 miles (range 4-211 miles). One patient did not undergo intervention due to frailty and two died before reaching the operating theatre. A total of 23 patients underwent endovascular repair, 9 hybrid repair and 17 open surgery. Median follow-up was 12 months (range 1-43 months). Complications included paraplegia (n = 3), stroke (n = 2), type IA endoleak (n = 4); 30-day and in-hospital mortality were 16% and 27%. For patients discharged alive from hospital, one-year survival was 67%. Conclusions Although the number of patients with rSRAD is low and those who are transferred alive are a self-selecting group, this study suggests that transfer of such patients to a specialist vascular centre is associated with acceptable mortality rates following emergency complex aortic repair.

Long-term results of intra-arterial onyx injection for type II endoleaks following endovascular aneurysm repair.

Purpose The aim of this paper is to report our experience of type II endoleak treatment after endovascular aneurysm repair with intra-arterial injection of the embolizing liquid material, Onyx liquid embolic system. Methods From 2005 to 2012, we performed a retrospective review of 600 patients, who underwent endovascular repair of an abdominal aortic aneurysm. During this period, 18 patients were treated with Onyx for type II endoleaks. Principal findings The source of the endoleak was the internal iliac artery in seven cases, inferior mesenteric artery in seven cases and lumbar arteries in four cases. Immediate technical success was achieved in all patients and no endoleak from the treated vessel recurred. During a mean follow-up of 19 months, no major morbidity or mortality occurred, and one-year survival was 100%. Conclusions Treatment of type II endoleaks with Onyx is safe and effective over a significant time period.

Contemporary management of splanchnic and renal artery aneurysms: results of endovascular compared with open surgery from two European vascular centers.

INTRODUCTION: Splanchnic and renal artery aneurysms (SRAAs) are uncommon but potentially life-threatening in case of rupture. Whether these aneurysms are best treated by open repair or endovascular intervention is unknown. The aim of this retrospective study is to report the results of open and endovascular repairs in two European institutions over a fifteen-year period. We have reviewed the available literature published over the 10 last years. METHODS: All patients with SRAAs diagnosed from 1995 to 2010 in St Marys Hospital (London, UK) and Henri Mondor Hospital (Créteil, France) were reviewed. Preoperative clinical and anatomical data, operative management and outcomes were recorded from the charts and analyzed. RESULTS: 40 patients with 51 SRAAs were identified. There were 21 males and 19 females with a mean age of 57 ± 14.9 years. The aneurysms locations were: 14 (27%) renal, 11 (22%) splenic, 7 (14%) celiac trunk, 7 (14%) superior mesenteric artery, 4 (8%) hepatic, 4 (8%) pancreaticoduodenal arcades, 3 (6%) left gastric and 1 (2%) gastroduodenal. 4 patients presented with a ruptured SRAA. 17 SRAAs in 16 patients were treated by open repair, 15 in 15 patients were treated endoluminally and 17 (mean diameter: 18 mm, range: 8-75 mm) were managed conservatively. One patient with metastatic pulmonary cancer with two mycotic aneurysms of the superior mesenteric artery (75 mm) and celiac trunk (15 mm) was palliated. After endovascular treatment, the immediate technical success rate was 100%. There was no significant difference between open repair and endovascular patients in terms of 30-day post-operative mortality rate and peri-operative complications. No in-hospital death occurred in patients treated electively. Postoperatively, four patients (1 ruptured and 3 elective) suffered non-lethal mild to severe complication in the open repair group, as compared with one in the endovascular group (p = .34). The mean length of stay was significantly higher after open repair as compared with endovascular repair (17 days, range: 8-56 days vs. 4 days, range: 2-6; p < .001). The mean follow-up time was 17.8 months (range: 0-143 months) after open repair, 15.8 months (range: 0-121 months) after endovascular treatment, and 24.8 (range: 3-64 months) for patient being managed conservatively. No late death related to the VAA occurred. In each group, 2 successful reoperations were deemed necessary. In the endovascular group, two patients presented a reperfusion of the aneurysmal sac at 6 and 24 months respectively. CONCLUSION: No significant difference in term of 30-day mortality and post-operative complication rates could be identified between open repair and endovascular treatment in the present series. Endovascular treatment is a safe alternative to open repair but patients are exposed to the risk of aneurysmal reperfusion. This mandates careful long-term imaging follow up in patients treated endoluminally.

The suitability of thoraco-abdominal aortic aneurysms for branched or fenestrated stent grafts--and the development of a new scoring method to aid case assessment.

OBJECTIVE: To determine the proportion of TAAAs which might be suitable for pure endovascular repair based on aneurysm morphology and to develop an MDCTA based scoring system to grade case complexity. DESIGN: 70 consecutive MDCTA of patients with TAAAs were analysed in relation to specific morphological characteristics. METHODS: The characteristics included potential stent landing zone lengths, arch angulation, thoraco-abdominal aorta angulation, branch vessel origin stenosis, access tortuosity/diameter and aortic dissection. RESULTS: 60% of TAAAs would be suitable for branched/fenestrated stent grafting but 40% are unsuitable due to adverse anatomy. 27% had an aortic arch angulation of ≤ 110° and 24% had descending thoracic aorta angulation of ≤ 90°. Significant ostial stenosis was identified in 31% of celiac arteries, 7% superior mesenteric arteries, 24% left renal artery and 19% right renal arteries. 11% of left common iliac and 7% right common iliac arteries had angulation of ≤ 70°. There were 26 cases with aortic dissection and 54% of these had a true lumen of ≤ 26 mm. CONCLUSION: Successful fenestrated/branched stent graft repair of TAAAs requires adequate landing zones, cannulation of visceral arteries and suitable diameter access vessels. 60% of TAAAs studied were suitable for branched/fenestrated stent graft repair but 40% of TAAAs were unsuitable; aortic angulation, visceral vessel ostial stenosis and dissection true lumen diameter were the principle issues. Development in stent technology may address these anatomical challenges.

Hybrid repair of the aortic arch in patients with extensive aortic disease.

OBJECTIVE: To evaluate the outcome of hybrid treatment of the aortic arch with supra-aortic debranching and endovascular stent-graft repair in a selected group of patients with complex disease. DESIGN: Case series study with retrospective analysis of prospectively collected non-randomised data. METHODS: Patients with hybrid repair of complex arch disease at a single centre over a 6-year period were enrolled in the study. Only patients with extensive arch pathologies requiring debranching of at least the left carotid artery were considered. Patients were divided into those who underwent complete and partial supra-aortic revascularisation. The χ2 test was used to evaluate differences in outcomes. Logistic regression analyses were applied to identify predictors of poor outcome. RESULTS: A total of 33 patients were included in the study. Complete and partial arch repair was performed in nine and 24 patients, respectively. The aortic disease extended to the thoracic and abdominal aorta in 39% and 52% of the patients, respectively. One-third of the patients (30%) were treated on an urgent/emergency basis. Elective 30-day mortality and morbidity rates were 13% and 35%, respectively. Early mortality was significantly higher in the complete arch repair group (p=0.046). Pre-existing renal impairment was identified as a poor prognostic factor. All extra-anatomic bypasses remained patent and no aortic disease-related deaths occurred during a mean follow-up period of 23 months (range, 1.5-58 months). Complete arch repair was associated with an increased incidence of late endoleak (p=0.018). CONCLUSIONS: Hybrid treatment of the aortic arch provides a feasible alternative treatment in patients who are high risk for conventional open surgical repair. Careful selection of patients is required to achieve satisfactory results.

Recent advances in thoraco-abdominal aortic aneurysm repair.

Thoraco-abdominal aortic aneurysm repair remains a formidable challenge to vascular surgeons. The traditional repair of thoraco-laparotomy with aortic cross-clamping is associated with a high morbidity and mortality despite significant advances in perioperative critical care, anaesthetic and surgical techniques. The advent of the endovascular revolution has shown a marked paradigm in the approach to all aneurysm repairs. As a logical progression from the open repair, the St Mary's visceral hybrid repair combines traditional open techniques (retrograde visceral and renal revascularisation via mid-line laparotomy) with endovascular stent grafting, thereby avoiding the need for thoracotomy and aortic cross-clamping. In specialist centres, the results have been encouraging and easily comparable to the open repair. The technique has been used in several centres around the world and represents a robust, transferrable method of repairing thoraco-abdominal aortic aneurysms. Stent-grafting technologies have reached a point of sophistication that wholly endovascular methods of repairing thoraco-abdominal aortic aneurysms are being performed in several centres around the world. Although these stent grafts have to be customised to the individual patient and are only suitable for certain types of aneurysmal anatomies, they represent the future of thoraco-abdominal aortic aneurysm repair. We review the history of thoraco-abdominal aortic aneurysm repair, the exciting advances in their treatment and discuss our approach to the management of thoraco-abdominal aortic aneurysms in the 21st century.

Endovascular management of thoraco-abdominal aneurysms.

The recent advances in stent technology have provided a choice of techniques in the treatment of thoracoabdominal aortic aneurysms. These techniques should reduce the physiological insult associated with aneurysm repair. Because numbers are small and these techniques are still being perfected, there is as yet limited evidence for a significantly improved survival or reduced paraplegia rates. This evidence is particularly limited as early reported series were based upon patients deemed unfit for open repair. The choice of technique is influenced by a number of factors including aneurysm anatomy and physiological reserve of the patient. It must be remembered that a large proportion of these patients are elderly with significant co-morbidities. Thoracoabdominal aneurysms often affect an extensive section of the aorta and this region provides a major proportion of spinal perfusion. Treatment of these patients--by any modality--will always carry significant risks and this explains the persistently high morbidity and mortality figures. Case selection and balancing the risks of treatment with those of the disease itself will remain crucial in providing best management to our patients. With future device improvements a greater proportion of patients may be suitable for endovascular aneurysm repair. The single biggest advance needed to facilitate this is the development of a system allowing 'off the shelf' stenting of urgent cases, but in-situ fenestration will be required to facilitate this and such a technique remains experimental at present.

The visceral hybrid repair of thoraco-abdominal aortic aneurysms--a collaborative approach.

OBJECTIVE: To report the collaborative data of 3 major European Vascular Units using the 'visceral hybrid' procedure for thoraco-abdominal aortic aneurysms and dissections. METHODS: A consecutive series of 107 urgent and elective high-risk patients were included in a prospectively collected database. RESULTS: All stents involved the entire thoracic and abdominal aorta with left subclavian coverage in 19 and revascularisation in 12. The distal landing zone was in the infra-renal aorta in 75% and in the iliac artery in 25%. The 30-day mortality rate was 16/107 (14.95%). 13/107 (12.1%) of the patients suffered spinal cord ischaemia which was complete and permanent in 9/12 (8.4%). 4 patients (3.7%) required long term dialysis and a segment of gut infarction requiring resection occurred in 3 (2.8%). Most patients had visceral bypass grafting and aortic stent-grafting performed in one stage. In 18 patients the stenting was performed later. Three of these patients ruptured before the stenting procedure was undertaken. CONCLUSION: These early results of visceral hybrid repair for high-risk patients with complex thoraco-abdominal aortic aneurysms are encouraging, in a group of patients in whom fenestrated/branched stent-grafting is not an option and open surgery hazardous.

Treatment of complex aneurysmal disease with fenestrated and branched stent grafts.

OBJECTIVES: To describe our experience of treating juxtarenal (JRAAA's <4mm neck) and thoracoabdominal aortic aneurysms (TAAA's) using fenestrated and branched stent graft technology. DESIGN: Prospective single centre experience. METHODS: Since 2005, 29 fenestrated/branched procedures have been performed. 15 patients are studied with JRAAAs (n=7; median neck length 0mm (IQR 0-3.8)) or TAAAs (type I (n=2), III (n=2), IV (n=4)). ASA grade III in 12/15. Maximum diameter of aneurysm 64 mm (56-74 mm). Aneurysms were excluded using covered stents or branches from the main body to patent visceral vessels (40 target vessels total). Pre-operative and follow-up CT scans (1, 3, and 12 months) were analysed by a single Vascular Interventional Radiologist. RESULTS: Technical success for cannulation and stenting of target vessels was 98%. In-hospital mortality was 0%. One patient underwent conversion to open repair. Five had major complications including one paraplegia (type III TAAA) with subsequent recovery. Median length of stay was 9 days (IQR 7-18.75). At a median follow-up of 12 months (9-14), CT confirmed 36/37 (97%) target vessels remain patent. Sac size increased >5 mm in one patient only. There were no type I endoleaks, three type II endoleaks (one embolised, two under surveillance) and three type III endoleaks (two successfully treated percutaneously, one aneurysm ruptured 18 months after endografting and died). CONCLUSION: In selected patients, fenestrated and branched stents appear to be a safe and effective alternative to surgery for juxtarenal and thoracoabdominal aneurysms. The complication and mortality rates are low. The long-term durability of this procedure, however, needs to be proven.

AAA benchmarking by Dr Foster: a cause for concern?

INTRODUCTION: The publication of interpretable performance data for hospitals is an important service. In November 2002, the medical benchmarking company Dr Foster published a league table based on the results of abdominal aortic aneurysm (AAA) repair. The purpose of our study was to establish the validity of the data used in benchmarking. PATIENTS AND METHODS: Data on elective infra-renal AAA (IRAAA) repair was obtained from three sources. Data used by Dr Foster was based on the hospital PAS system. The databases for both Dr Foster and PAS were analysed and cross-referenced to the vascular unit database maintained by a separately employed audit co-ordinator. RESULTS: Of 395 total aortic aneurysm repairs, 223 (56%) were identified as elective IRAAA repairs on the unit database. Of these, 125 were identified on the PAS database and 115 on the Dr Foster database. The number of deaths was the same in both the unit and Dr Foster databases (n = 11) but the Dr Foster database included deaths in patients who had undergone juxtarenal (n = 1), Type III TAAA (n = 2) and Type IV TAAA (n = 4) repairs and omitted 7 deaths following IRAAA. The sensitivity and specificity for the PAS dataset was 0.51 and 0.93, respectively. For Dr Foster, the results were worse with a sensitivity and specificity of 0.41 and 0.86, respectively. The accuracy of the data was 0.6 and 0.69 for Dr Foster and PAS, respectively. Standardised mortality ratios (SMRs) were used to rank hospitals. Dr Foster's published SMR for elective AAA repair for our unit was 160. The actual SMR was 67. CONCLUSIONS: Robust and accurate published league tables should be supported and commended but currently available data appear to be misleading and may cause unnecessary concern to patients.

Critical limb ischemia in the dialysis-dependent patient: infrainguinal vein bypass is justified.

The combination of critical limb ischemia and end-stage renal failure (ESRF, ie, dialysis- dependent) represents severe systemic atherosclerosis and is associated with a very poor medium-term survival. Many nephrologists and surgeons advocate primary amputation. We examined the recent experience in this unit to determine whether infrainguinal bypass in these patients can be justified. Retrospective study of all patients with critical limb ischemia and ESRF undergoing surgery in a regional vascular and renal unit between January 1996 and May 2003. Forty-two patients with ESRF (median age 65 years) were referred with critical limb ischemia. Seventeen patients underwent 24 (7 bilateral) infrainguinal bypasses (17 autologous vein, 7 polytetrafluoroethylene [PTFE] conduit; tissue loss in 21/24, 88%), and 25 patients had primary major amputations of 32 limbs. Early occlusion occurred in 5 grafts (21%, all 5/5 PTFE). In-hospital mortality was 13% in the bypass group, 24% in the amputation group. Median in-hospital stay was 59 days in the bypass group, 46 days in the amputation group. Thirty-day, 1- and 2-year survival was 88%, 50%, and 33% in the bypass group; 83%, 39%, and 35% in the amputation group. The limb salvage rate was 66% at 1 year. Seventy-five percent (18/24) of operated on limbs (15/17 of vein grafts) avoided major amputation at follow-up (median 18 months) or death. The combination of critical limb ischemia and end- stage renal failure carries a poor medium-term survival independent of primary amputation or surgical revascularization. Infrainguinal bypass in selected cases with vein conduit can, however, allow the majority of these patients to avoid major limb amputation.

The value of suction wound drain after carotid and femoral artery surgery: a randomised trial using duplex assessment of the volume of post-operative haematoma.

BACKGROUND: The use of vacuum suction drains after carotid endarterectomy (CEA) and groin dissection for arterial reconstruction surgery remains controversial. A large multicentre prospective randomised trial would be needed to show any difference if clinical end points (infection and haematoma) are used. Therefore, we conducted a study to evaluate the value of wound drainage using accurate duplex measurement of haematoma expecting a 25% difference in volume between drained and non-drained wounds. PATIENTS AND METHODS: Seventy consecutive patients undergoing CEA and 73 patients who underwent 106 groins dissection were separately and blindly randomised into two groups: group (a) with wound drain and group (b) without wound drain. A duplex scan was carried out post-operatively to document the presence and volume of any wound haematoma. RESULTS: The majority of wounds did not show any evidence of collections. 1. In the CEA patients duplex scan revealed wound haematoma in 8 patients with a median volume of 25 ml (5-65) in group (a) in comparison to 7 wound haematomas 31 ml (3-72) in group (b). Median suction drain drainage was 42 ml (10-120) when used. There was no significant difference between the two groups. Three patients 4.3% (two from the drain group) underwent evacuation of haematoma post-operatively.2. In the groin dissection patients most of the documented collections were trivial. Ultrasound scans showed 21 collections (20%), of these 7 (34%) were in group (a) and 14 (66%) were in group (b). There was no significant difference in wound collections between the two groups (p = 0.28). Only 5 collections (75%) exceeded 10 ml, three of them were in the drain group. One patient (1%), who did not have a drain, developed a wound collection, which needed re-exploration. When a drain was used the median drainage was 64.5 ml (range 10-220). CONCLUSION: These results based on accurate measurement of wound collection suggest that there is no benefit in terms of reduction of the volume of haematoma on wound drainage after CEA or arterial reconstruction surgery involving the groin. A selective policy of use of drainage is therefore recommended.

The relationship between plasma MMP-1, -7, -8 and -13 levels and embolic potential during carotid endoluminal intervention.

BACKGROUND: Patients undergoing carotid endoluminal intervention are at risk of embolic stroke even with the use of distal protection devices. Matrix metalloproteinases (MMPs) have been implicated as a causal factor in plaque instability leading to spontaneous embolisation. We investigated whether plasma MMP levels correlated with the embolisation during carotid endoluminal intervention. METHODS: Thirty circumferentially intact carotid endarterectomy specimens were subjected to a standardised angioplasty procedure in a pulsatile ex vivo model. Emboli collected in a series of distal filters were counted and sized. Plasma samples were collected pre-operatively and analysed for MMP-7 and MMP-8 levels using Western immunoblotting. MMP-1 and MMP-13 levels were determined using ELISA. Emboli number and maximum size were correlated with plasma levels of the MMPs using Spearmans rank. RESULTS: Total MMP-8 levels were related to maximum embolus size (r=0.442, p=0.005) but not emboli number (r=0.342, p=0.052). MMP-1, -7 and -13 were not correlated with either emboli number or with maximum embolus size. CONCLUSION: Pre-operative plasma MMP-8 levels are related to the size of emboli from plaques during carotid endovascular intervention. Further in vivo studies need to be performed to assess the importance of this finding. There is potential for development of plasma markers to identify those patients at greater risk of embolic stroke during carotid endoluminal intervention.

Carotid angioplasty in a pulsatile flow model: factors affecting embolic potential.

OBJECTIVES: Carotid endoluminal intervention is an alternative to surgery but carries a risk of embolic stroke even with distal protection devices. We investigated the clinical features and degree of stenosis related to number and size of emboli during carotid angioplasty. DESIGN: An experimental ex vivo study. MATERIALS: An ex vivo pulsatile flow model was used in which temperature, velocity, flow, pressure and viscosity characteristics were designed to simulate the carotid circulation. METHODS: Carotid endarterectomy specimens excised as intact cylinders (n = 28) were subjected to a standardised angioplasty procedure using radiological guidance. Emboli collected in filters placed distally were counted and sized using microscopy. RESULTS: Median number of emboli during angioplasty was 133 (range 15-1331). Median size of the largest embolus was 700 microns (range 75-2400). Severity of stenosis correlated with increased maximum size (r = 0.55, p = 0.012). Statin therapy >4 weeks pre-operatively was associated with reduced emboli number and size (54 (range 15-748) vs 247 (range 37-1331) [p = 0.023] and 400 microm (range 75-2400) vs 1300 microm (range 600-2200) [p = 0.022]). CONCLUSIONS: In this model a wide range of emboli number and size were produced. Number and size of embolic particles were highest in patients with high-grade stenoses not receiving statin therapy.

Reduction in the response to coronary and iliac artery injury with photodynamic therapy using 5-aminolaevulinic acid.

OBJECTIVE: Photodynamic therapy (PDT) uses red light (non-thermal, non-ionising) to activate a previously administered photosensitizing drug. This inhibits neointimal hyperplasia in injured arteries in small animals where it appears safe and well tolerated. Our aim was to develop a method for percutaneous application of PDT to iliac and coronary arteries in a large animal model and investigate its influence on the remodeling and intimal hyperplastic response to balloon injury. METHODS: Studies were undertaken on 13 juvenile Large White-Landrace crossbred pigs (15-20 kg). After intravenous administration of the photosensitizing agent 5-amino laevulinic acid (ALA), the arterial tree was accessed via the left common carotid artery and balloon injuries made by over-distension in both common iliacs (thirteen animals) and one or two main coronary arteries (eight animals). Half the injured sites were then illuminated with red laser light transmitted via the catheter. Animals were culled 28 days later and tissue harvested for histomorphometry. RESULTS: Compared with control injured vessels, PDT treated, balloon injured coronary arteries had a larger lumen (1.4 vs. 0.8 mm2, P = 0.002), larger area within the external elastic lamina (2.8 vs. 2.2 mm2, P = 0.006) and smaller area of neointimal hyperplasia (0.4 vs. 0.7 mm2, P = 0.06), 28 days after intervention. Less neointimal hyperplasia and the absence of negative remodeling resulted in the lumen of PDT-treated, injured segments being the same as that of adjacent reference segments (1.5 vs. 1.6 mm2). Similar trends, but with smaller differences, were seen in the iliac vessels. CONCLUSIONS: Intra-arterial, trans-catheter PDT favourably influences the arterial response to balloon injury in both the coronary and peripheral circulations. This technique offers a promising new approach to restenosis after endovascular procedures.