Mark Tyrrell

Endovascular treatment of thoracoabdominal aortic aneurysms

BACKGROUND Development in endograft design has extended endovascular treatment to include thoracoabdominal aortic aneurysms (TAAA). We report our experience using fenestrated and branched endografts in the management of TAAA. METHODS We analyzed a cohort of consecutive patients treated electively for TAAA using endovascular techniques between 2006 and 2011. All data were collected prospectively. The relationships between preoperative risk factors and clinical outcome were examined using univariate and multivariate statistical techniques. We also compared the outcomes between 33 previously published early cases (EC) with the last 56 later cases (LC). RESULTS Eighty-nine patients (83 men) were treated. Median age was 69 years. All patients were deemed unfit for open surgery. The 30-day and in-hospital mortality rates were 8.9% and 10%, respectively. Multivariate analysis showed in-hospital mortality was associated with preoperative chronic renal failure and advanced age. Higher postoperative mean arterial blood pressure was a protective factor. Technical success rate was 96.6% (94% and 98% in the EC and LC groups, respectively; P = .14). The spinal cord ischemia (SCI) rate was 7.8% (15% and 3% in the EC and LC groups, respectively; P = .063) and was associated with chronic obstructive pulmonary disease and procedure duration. Six patients (6.7%) required temporary filtration, but none required permanent renal support (associated with left ventricular ejection fraction <40% and procedure duration). Median procedure duration decreased from 232 to 203 minutes (P = .01) in the EC and LC groups, respectively. Actuarial survival was 86.8% ± 3.7% at 1 year and 74.7% ± 6% at 2 years. CONCLUSIONS Although we have treated a cohort at high operative risk, our midterm results compare favorably with the published series of conventional surgery. Accurate hemodynamic control represented by high-normal perioperative blood pressure seems to protect against severe postoperative complications.

Early Results of Fenestrated Endovascular Repair of Juxtarenal Aortic Aneurysms in the United Kingdom

Background— Fenestrated endovascular repair of abdominal aortic aneurysms has been proposed as an alternative to open surgery for juxtarenal and pararenal abdominal aortic aneurysms. At present, the evidence base for this procedure is predominantly limited to single-center or single-operator series. The aim of this study was to present nationwide early results of fenestrated endovascular repair in the United Kingdom. Methods and Results— All patients who underwent fenestrated endovascular repair between January 2007 and December 2010 at experienced institutions in the United Kingdom(>10 procedures) were retrospectively studied by use of the GLOBALSTAR database. Site-reported data relating to patient demographics, aneurysm morphology, procedural details, and outcome were recorded. Data from 318 patients were obtained from 14 centers. Primary procedural success was achieved in 99% (316/318); perioperative mortality was 4.1%, and intraoperative target vessel loss was observed in 5 of 889 target vessels (0.6%). The early reintervention (<30 days) rate was 7% (22/318). There were 11 deaths during follow-up; none were aneurysm-related. Survival by Kaplan–Meier analysis was 94% (SE 0.01), 91% (0.02), and 89% (0.02) at 1, 2, and 3 years, respectively. Freedom from target vessel loss was 93% (0.02), 91% (0.02), and 85% (0.06), and freedom from late secondary intervention (>30 days) was 90% (0.02), 86% (0.03), and 70% (0.08) at 1, 2, and 3 years. Conclusions— In this national sample, fenestrated endovascular repair has been performed with a high degree of technical and clinical success. Late survival and target vessel patency are satisfactory. These results support continued use and evaluation of this technique for juxtarenal aneurysms, but illustrate the need for a more robust evidence base.

Comparison among transposed brachiobasilic, brachiobrachial arteriovenous fistulas and Flixene™ vascular graft.

Objective To compare the outcomes of 3 upper arm access types: transposed brachiobasilic arteriovenous fistula (BBAVF), autogenous brachial vein–brachial artery access (ABBA), and a new type of ePTFE graft (Flixene™ graft) (AVG), in a consecutive series of patients treated in a tertiary centre. Methods A prospective, computerized access database was analysed retrospectively to identify all patients undergoing BBAVF, ABBA, or AVG between January 1, 2008, and December 31, 2009. Results A total of 108 patients were identified; of whom 45 had BBAVF, 15 ABBA, and 48 ePTFE brachioaxillary AVG. Early failure was similar in all 3 groups. The 18–month functional patency rates for the ABBAs, BBAVFs, and grafts were 27%, 51%, and 55%, respectively. The median time to first use for AVGs was significantly shorter (p<0.0001). Complications were not more frequent in AVGs than ABBAs and BBAVFs (p=0.127). The total number of access interventions was similar between the AVG and ABBA groups (p=0.58), but it was significantly higher in the AVG group compared with the BBAVF group (p<0.0001). Conclusions This study supports the current recommendations of the NKF Kidney Disease Outcomes Quality Initiative for using BBAVFs as third choice after radiocephalic and brachiocephalic arteriovenous fistulas. We also showed good results with a new type of prosthetic graft (Flixene™ graft) that allows cannulation within days of implantation. We now favour the use of this graft instead of basilic vein transposition in elderly patients with short life expectancy and urgent need of renal access.

Early Experience of Endovascular Repair of Post-dissection Aneurysms Involving the Thoraco-abdominal Aorta and the Arch

OBJECTIVES Outcomes are reported in management of post-dissection aneurysms involving the aortic arch and/or thoraco-abdominal segment (TAAA) treated with fenestrated and branched (complex) endografts. METHODS This report includes all patients with chronic post-dissection aneurysms >55 mm in diameter, deemed unfit for open surgery, treated using complex endografts between October 2011 and March 2015. When appropriate, staged management strategies including left subclavian artery revascularization, thoracic endografting, dissection flap fenestration or tear enlargement, and other endovascular procedures were performed at least 3 weeks prior to definitive complex endovascular repair. The following outcome data were collected prospectively at discharge, 12 months and annually thereafter: technical success, endoleaks, target vessel patency, false lumen patency, aneurysm diameter, major and minor complications, re-interventions, and mortality. RESULTS The cohort comprised 23 patients with a median age of 65 years. Staged procedures were performed in 14 patients (61%). Seven patients with dissections involving the arch were treated with inner branched endografts, and 16 TAAA patients were treated with fenestrated or branched endografts. The technical success rate was 71% following arch repair and 100% following TAAA repair. During early follow up, one of the arch group patients died and one in the TAAA group suffered spinal cord ischemia. The median follow up was 12 months (range 3-48), during which time one patient died of causes unrelated to aneurysm or treatment. Two early re-interventions were performed in the arch group to correct access vessel complications and there were a further two late re-interventions in the TAAA group to treat endoleaks. All target vessels (n = 72) remained patent. CONCLUSIONS This experience indicates that complex endovascular repair of post-dissection aneurysms is a viable alternative to open repair in patients deemed unfit for open surgery. There are insufficient data to allow comparison with the outcome of open surgery in anatomically similar, but fit, patients.

Debate: Whether fenestrated endografts should be limited to a small number of specialized centers

Until fairly recently, experience with advanced endovascular technologies, including fenestrated endovascular repair (FEVAR), has been limited to a relatively small number of practitioners worldwide. Excellent outcomes have been achieved by these accomplished surgeons who, at least initially, have primarily used custom-made devices constructed by a single endograft manufacturer. Access to this technology has been limited by the skills necessary for such procedures and by the customization process with industry partners. However, several issues are changing rapidly with FEVAR. Increasing numbers of surgeons now have the necessary endovascular skills, and off-the-shelf endografts from several manufacturers have become, or are becoming, available. Also, the regulatory landscape is changing with device approval in the United States. Surgeons and patients alike are anticipating the widespread adoption of this advanced technology that will surely benefit increasing numbers of patients. Or will it? Will widespread adoption in a larger number of smaller-volume hospitals, by less experienced surgeons, result in poor patient outcomes, or will excellent results continue with more patients benefitting from these technologic advances? These are important questions to ask before such adoption and are the subject of this debate.

A report of spinal cord ischemia following endovascular aneurysm repair of an aneurysm with a large thrombus burden and complex iliac anatomy.

We report a case of paraplegia occurring after an elective endovascular aneurysm repair (EVAR) that was reversed by cerebrospinal fluid (CSF) drainage. This case report highlights the reality that the endovascular management of abdominal aortic aneurysms (AAAs) with large volumes of mural thrombus and complex iliac anatomy can be complicated by spinal cord ischemia (SCI). The presumed mechanism of SCI is dissemination of atherosclerotic material during protracted catheter and wire manipulations. Embolization of internal iliac arteries (IIAs), profunda femoral arteries, and possibly other arterial networks may explain the delayed presentation. The complex iliac anatomy necessitating covering of one and reconstruction of the other hypogastric artery and the prolonged operative time may be 2 other contributing factors. The prompt CSF drainage may reverse the neurologic deficit.

Autogenous Brachial—Brachial Fistula for Vein Access. Haemodynamic Factors Predicting Outcome and 1 Year Clinical Data

UNLABELLED Two-stage autogenous brachial vein-brachial artery access (ABBA) has been proposed as an option where adequate superficial vein is not available for the creation of conventional haemodialysis fistulae. METHODS This report depicts the clinical outcome of a series of 17 consecutive patients who underwent ABBA in a single centre. Of the 17 patients, nine had had at least one previous arterioventricular (AV) fistula or graft, and eight were new to haemodialysis. Patencies were assessed using the Kaplan-Meier survival analysis. RESULTS In 14 patients, the brachial vein was transposed (82%) and the time to transposition ranged from 4 to 26 weeks (median time: 6 weeks). The functional patency rate was 45.75% at 12 months. After stage one, all fistulas that went on to develop well had a brachial vein flow of at least 900 ml min(-1), and this was significantly higher than in fistulas that failed to develop (p=0.005). The maturation rate in our study was 65% and the median time to cannulation of the fistula was 8 weeks from the stage 1. Of the 17 patients, 12 (71%) experienced at least one complication. Ten (59%) demonstrated moderate-to-severe stenoses; eight of which necessitated angioplasty and/or percutaneous mechanical thrombolysis. CONCLUSIONS ABBA was characterised by a high incidence of complications and a long period to achieve maturation. Despite close monitoring and a high rate of secondary interventions, the patency rate was low. With this experience, we now only consider it an alternative in patients without adequate superficial veins, who have had failed grafts or where there is a very high risk of infection.

The current management of carotid atherosclerotic disease: who, when and how?

Ischaemic stroke represents a major health hazard in the western world, which has a severe impact on society and the health-care system. Roughly, 10% of all first ischaemic strokes can be attributed to significant atherosclerotic disease of the carotid arteries. Correct management of these lesions is essential in the prevention and treatment of carotid disease-related ischaemic events. The close relationship between diagnosis and medical and surgical management makes it necessary that all involved physicians and surgeons have profound knowledge of management strategies beyond their specific speciality. Continuous improvement in pharmacological therapy and operative techniques as well as frequently changing guidelines represent a constant challenge for the individual health-care professional. This review gives a thorough outline of the up-to-date evidence-based management of carotid artery disease and discusses its current controversies.

Part One: For the Motion. Fenestrated Endografts Should be Restricted to a Small Number of Specialized Centers

Death as a consequence of aortic catastrophe is a common event among the middle-aged and retired population. It is the 12th most common cause of death in the United States. Although abdominal aortic aneurysms (AAAs) and ascending aortic aneurysms are the more frequent, descending thoracic aortic aneurysms (TAAs) and thoracoabdominal aortic aneurysms (T-AAAs) are not rare, having an estimated incidence of 10.4 cases per 100,000 personyears. Aortic aneurysms are generally identified serendipitously (although AAA screening programs are being set up in some countries). The vast majority of aortic disease is symptom-free. The prevention of early death in exchange for life-long morbidity is an unacceptable outcome. “Primum non nocere” e if we are to usefully treat aneurysms, it is self-evident that the attendant therapeutic risks have to be contained. Once identified, prophylactic aneurysm repair is not without hazard and the risks can be shown to be related to patient selection, operator and institutional experience, the proportion of cases done endovascularly and the complexity of the repair. We will argue that these phenomena mandate that aortic repair, particularly complex endovascular aortic repair, should be restricted to specialist high volume centers.

Carotid endarterectomy: where do we stand at present?

PURPOSE OF REVIEW The introduction of endovascular techniques and improvements in the medical management of atherosclerotic carotid lesions have led to changes in the modern management of stroke. The purpose of this review is to summarize the latest developments in surgical carotid intervention and highlight the current controversies. RECENT FINDINGS The predominant controversies that dominate the correct surgical management of carotid atherosclerotic disease are: Notwithstanding the results of the Carotid Revascularisation Endarterectomy versus Stenting Trial, does carotid artery stenting produce equivalent outcomes to surgical carotid endarterectomy? Should recent developments in best medical management of these lesions and changing socioeconomic factors restrict the indication for surgical intervention for asymptomatic lesions? What is the ideal time frame for carotid interventions in symptomatic patients? SUMMARY There is insufficient current or historic evidence to resolve these controversies and further large randomized controlled trials are therefore required. The current knowledge limits are explored.