David G. Cooper

Neurological complications after left subclavian artery coverage during thoracic endovascular aortic repair: a systematic review and meta-analysis.

INTRODUCTION Recent studies suggest an increased risk of neurologic complications after coverage of the left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR). The preventative role of preoperative revascularization of the LSA using carotid-subclavian bypass or transposition remains controversial. We assessed this increased risk and the role of revascularization by undertaking a systematic review and meta-analysis of the literature. METHODS In the absence of any randomized controlled trials, the Pubmed and Embase databases were searched to identify all series reporting TEVAR without LSA coverage compared with LSA coverage with and without revascularization. The incidence of neurologic complications, namely cerebrovascular accident (CVA) and spinal cord ischemia (SCI), were recorded for each group. Pooled odds ratios (POR) were then calculated for postoperative CVA and SCI. RESULTS Compared with patients without LSA coverage, the risk of CVA was increased both in patients with LSA coverage alone (4.7% vs 2.7%; POR, 2.28; 95% confidence interval [CI], 1.28-4.09; P = .005) and in those with LSA coverage after revascularization (4.1% vs 2.6%; POR, 3.18; 95% CI, 1.17-8.65; P = .02). The risk of SCI was also increased in patients requiring LSA coverage (2.8% vs 2.3%; POR, 2.39; 95% CI, 1.30-4.39; P = .005) but not for LSA coverage after revascularization (0.8% vs 2.7%; POR, 1.69; 95% CI, 0.56-5.15; P = .35). CONCLUSION The risk of neurologic complications is increased after coverage of the LSA during TEVAR. Preemptive revascularization offers no protection against CVA, perhaps indicating a heterogeneous etiology. Revascularization may reduce the risk of SCI, although limited data tempers this conclusion. Improved or perhaps compulsory reporting to registries of a minimum data set may help further assess the exact etiology of these complications and identify a higher-risk subset of patients in whom revascularization might prove protective.

Remote Ischemic Preconditioning for Renal and Cardiac Protection during Endovascular Aneurysm Repair: A Randomized Controlled Trial

Purpose: To report a randomized clinical trial designed to determine if remote ischemic preconditioning (IP) has the ability to reduce renal and cardiac damage following endovascular aneurysm repair (EVAR). Methods: Forty patients (all men; mean age 76±7 years) with abdominal aortic aneurysms averaging 6.3±0.8 cm in diameter were enrolled in the trial from November 2006 to January 2008. Eighteen patients (mean age 74 years, range 72–81) were randomized to preconditioning and completed the full remote IP protocol; there were no withdrawals. Twenty-two patients (mean age 76 years, range 66–80) were assigned to the control group. Remote IP was induced using sequential lower limb ischemia. Serum and urinary markers of renal and cardiac injury were compared between the groups. Results: Urinary retinol binding protein (RBP) levels increased 10-fold from a median of 235 µmol/L to 2356 µmol/L at 24 hours (p=0.0001). There was a lower increase in the preconditioned group, from 167 µmol/L to 413 µmol/L at 24 hours (p=0.04). The median urinary albumin:creatinine ratio was significantly lower in the preconditioned group at 24 hours (5 versus 8.8, p=0.06). There were no differences in the rates of renal impairment or major adverse cardiac events. Conclusion: Remote preconditioning reduces urinary biomarkers of renal injury in patients undergoing elective EVAR. This small pilot trial was unable to detect an effect on clinical endpoints; further trials are warranted.

Treating the Thoracic Aorta in Marfan Syndrome: Surgery or TEVAR?

Marfan syndrome (MFS) is an inherited disorder of connective tissue that is historically associated with high mortality due to disorders of the cardiovascular system. Over the past 40 years, surgery to the aortic root and thoracoabdominal aorta has resulted in a significantly prolonged life expectancy. More recently, techniques for endovascular repair of the aortic complications of MFS have been described. In this article we review the relative merits of open and endovascular approaches to thoracic aortic complications in MFS, comparing outcomes from contemporary literature. A reasonably large body of evidence has developed concerning the surgical treatment of the aortic root, ascending thoracic aorta, and arch in MFS. It is clear from large series that pathology, such as acute type A dissections and aneurysmal dilatation, can be successfully repaired with low mortality. Recently published series, although reporting smaller numbers, have demonstrated that the same is true for open surgical replacement of descending thoracic and thoracoabdominal aortic aneurysms. The evidence for thoracic endovascular aortic repair in MFS is much more limited. Small series and registry or case reports describe a heterogeneous group of patients with only short-term follow-up. Outcomes of endovascular repair are mixed, with questionable longevity. Reoperation is, however, common in MFS, and minimally invasive techniques may provide a bridging role or alternative solution when revisiting the hostile surgical field.

Impact of the Type of Anesthesia on Outcome after Elective Endovascular Aortic Aneurysm Repair: Literature Review

The type of anesthesia used during aneurysm repair affects postoperative outcomes for the patient. Although endovascular aneurysm repair (EVAR) appears to improve surgical outcomes, by convention, general anesthesia remains predominantly used. The aim of this study was to compare the impact of the type of anesthesia (ie, locoregional versus general anesthesia) on the outcomes following EVAR. A literature search was carried out using the PubMed search engine to find relevant published articles that compared locoregional and general anesthesia in patients undergoing EVAR. The review of the selected studies showed that although patients in the locoregional group were less medically fit compared with those in the general anesthesia group, there was a reduction in the cardiovascular support required during and after the surgery, postoperative hospital stay, intensive care unit (ICU) stay, and postoperative mortality and morbidity. Although there is no level 1 evidence for or against locoregional anesthesia in EVAR, conventionally, EVAR has been performed under general anesthesia. But this is rooted in tradition rather than evidence. This review suggests that locoregional anesthesia can improve postoperative outcomes following EVAR by reducing hospital stay, ICU stay, mortality, and morbidity, although other factors may also have some influence.

Great Saphenous Vein Harvesting: A Systematic Review and Meta-Analysis of Open Versus Endoscopic Techniques

Background: The great saphenous vein is frequently harvested for use as a conduit in lower limb bypass surgery. A number of papers advocate the use of an endoscopic technique rather than a traditional open technique to minimize the associated morbidity. We undertook a systematic review and meta-analysis to compare morbidity associated with these 2 techniques. Method: Medline, PubMed, and secondary referencing identified 16 randomized control trials comparing these 2 methods of harvesting. Primary outcome measures were infection, hematoma, and wound dehiscence and pooled odds ratios (POR) were calculated using a random effects model. Results: Sixteen trials (3689 patients) were identified. Overall complications (POR 7.03), infection (POR 8.08), and wound dehiscence (POR 8.23) were all significantly more common in the open harvesting group compared to the endoscopic group. Conclusion: Endoscopic techniques have a role in vein harvesting but are operator dependent and therefore are only a preferable modality compared to open harvesting methods in experienced hands. More research is required to establish whether long-term patency rates are comparable for the 2 techniques.

Atrial fibrillation following elective open abdominal aortic aneurysm repair

BACKGROUND Atrial fibrillation is a common complication following major vascular surgery. It is often considered to be relatively benign but may represent the first sign of cardiac and non-cardiac complications. We conducted a retrospective study to determine the incidence and clinical associations of atrial fibrillation following open elective abdominal aortic aneurysm repair as well as its effect on prognosis. METHODS The case-notes of 200 consecutive patients undergoing open aneurysm repair were reviewed. Known pre-operative and intra-operative risk factors and potential post-operative associations with new-onset AF were recorded. Significant univariate correlates with AF were entered into a forward stepwise logistic regression model to test for independence. The effect of new-onset AF on long-term prognosis was assessed. RESULTS AF developed in 20 patients (10%) post-operatively. Previous cerebrovascular disease, aneurysm size and post-operative cardiac failure were associated with post-operative AF in univariate analyses. Cerebrovascular disease and post-operative cardiac failure were independently associated with new-onset AF. AF patients had a longer hospital stay. There was no difference in survival between those patients with and without new-onset AF. CONCLUSION New-onset AF is a common complication of open abdominal aortic aneurysm surgery and may indicate an underlying myocardial infarction. It is associated with a longer hospital stay and an increased risk of cardiac failure. Assessed and treated appropriately, it appears to have no effect on long-term prognosis.

First-Bite Syndrome Complicating Carotid Endarterectomy: A Case Report and Literature Review

First-bite syndrome (FBS) is an infrequently encountered complication of parapharyngeal space surgery. Patients experience excruciating pain in the ipsiltateral parotid gland region at the first bite of each meal, which improves with subsequent mastication. This is thought to be due to parotid gland sympathetic denervation from surgery with resultant hypersensitivity to parasympathetic impulses. There is no consensus on best treatment for FBS although symptoms tend to improve with time. There are only 2 case reports linking carotid endarterectomy and FBS so far. We report the third case of FBS after carotid endarterectomy to raise awareness among vascular surgeons of the possibility of this complication.

Comparison of Aortomonoiliac Endovascular Aneurysm Repair versus a Bifurcated Stent-Graft: Analysis of Perioperative Morbidity and Mortality

Purpose: To compare the perioperative morbidity and mortality following endovascular aneurysm repair (EVAR) with a bifurcated stent-graft versus an aortomonoiliac stent-graft combined with a femorofemoral crossover graft. Methods: A prospectively maintained database of patients undergoing EVAR over a 7-year period (January 2001 to June 2008) was interrogated retrospectively to identify all patients receiving either a bifurcated or an aortomonoiliac stent-graft. Patients undergoing emergency treatment or renal/mesenteric fenestrated or iliac branched EVAR were excluded. Data retrieval found 210 patients (194 men; mean age 75 years) who had been treated with 41 aortomonoiliac stent-grafts and 169 bifurcated devices. The impact of preoperative and intraoperative variables on postoperative morbidity was assessed by means of univariate and multivariate logistic regression analysis. Results: Significant postoperative complications occurred in 41% (17/41) of aortomonoiliac stent-graft patients compared to 14% (23/169) of bifurcated stent-graft patients (p=0.0001). Univariate logistic regression analyses identified patient age, operating time, and implantation of an aortomonoiliac stent-graft as significant predictors of postoperative complications. In a multivariate logistic regression model, only implantation of an aortomonoiliac stent-graft was independently associated with postoperative complications (p=0.003). Conclusion: Compared to EVAR with a bifurcated device, the implantation of an aortomonoiliac stent-graft and crossover bypass is associated with higher patient morbidity similar to rates reported after open repair. These patients comprise a high-risk endovascular group and require careful postoperative management in order to minimize complications.

Emergency endovascular management of peripheral artery aneurysms and pseudoaneurysms – a review

Endovascular stenting has been successfully employed in the management of aortic aneurysms; however, its use in managing peripheral arterial conditions remains questionable. We review the utility of endovascular technique in the management of peripheral arterial conditions like aneurysms, pseudoaneurysms and arterio-venous fistulas in the emergency setting. Though long term data about graft patency rates is not yet available, the endovascular approach appears to be a useful minimally invasive technique in situations where open repair is either difficult or not feasible.

Hybrid Endovascular Repair of an Aneurysmal Chronic Type B Dissection in a Patient with Marfan Syndrome With an Aberrant Right Subclavian Artery

Abnormal aortic arch anatomy is relatively uncommon but most frequently involves an aberrant right subclavian artery. Rarely, it is associated with aneurysmal dilatation of a chronic type B dissection. Under such circumstances, the abnormal anatomy may complicate therapeutics options. Furthermore, controversy exists regarding the use of surgical or endovascular techniques in patients with aortic aneurysms and underlying arteriopathies. The current literature is limited with regard to reporting of the latter. We present a hybrid approach to repair such an aneurysm in a patient with Marfan syndrome. In a 2-stage procedure, involving initial supra-aortic bypass to all aortic arch branches, followed by endovascular stent graft deployment, the aneurysm was successfully excluded. There were no immediate complications and no evidence of endoleak at 3 months postoperatively, with thrombosis of the false lumen in the chest. By adapting hybrid open and endovascular techniques, complex thoracic aneurysms may be successfully treated in the short term in the presence of an underlying arteriopathy.