Retrograde Cerebral Perfusion May Decrease Stroke Risk During Elective Aortic Arch Surgery.

OBJECTIVE: Controversy remains regarding the optimal neuroprotection strategy for elective hemiarch replacement (HEMI). This study sought to compare outcomes in patients who underwent HEMI utilizing the 2 most common contemporary methods of cerebral protection. METHODS: The ARCH international aortic database was queried, and 782 patients undergoing elective HEMI with circulatory arrest from 2007 to 2012 were identified. There were 418 patients who underwent HEMI using moderate hypothermia (nasopharyngeal temperature 20.1 to 28.0 °C) and antegrade cerebral perfusion (MHCA/ACP). There were 364 patients who underwent HEMI using deep hypothermia (nasopharyngeal temperature 14.1 to 20 °C) and retrograde cerebral perfusion (DHCA/RCP). Adverse outcomes were compared between the groups using both univariable and multivariable analyses. RESULTS: Patients who underwent MHCA/ACP were older (64 vs 61 years, P = 0.01) and more frequently had peripheral vascular disease than DHCA/RCP patients (28.5% vs 7.1%, P < 0.001). Patients in the DHCA/RCP group had a greater incidence of full aortic root replacement (55.8% vs 26.4%, P < 0.001) and more frequently had a central cannulation strategy (83% vs 55.7%, P < 0.001). Cardiopulmonary bypass (170 vs 157 min, P = 0.002) and aortic cross-clamp (134 vs 92 min, P < 0.001) times were significantly longer in the DHCA/RCP group. On univariable analysis, overall mortality was statistically similar between groups (MHCA/ACP 3.4% vs DHCA/RCP 2.3%, P = 0.47), but permanent neurologic deficits were significantly lower in the DHCA/RCP cohort (MHCA/ACP 3.9% vs DHCA/RCP 1.0%, P = 0.02). Multivariable analysis showed no difference in mortality nor perioperative stroke between perfusion cohorts. CONCLUSIONS: Both MHCA/ACP and DHCA/RCP are excellent neuroprotective strategies that produce low mortality in patients undergoing elective HEMI. DHCA/RCP may demonstrate theoretically improved neurologic outcomes compared with MHCA/ACP, but this topic warrants further study.

The ARCH Projects: design and rationale (IAASSG 001).

OBJECTIVE: A number of factors limit the effectiveness of current aortic arch studies in assessing optimal neuroprotection strategies, including insufficient patient numbers, heterogenous definitions of clinical variables, multiple technical strategies, inadequate reporting of surgical outcomes and a lack of collaborative effort. We have formed an international coalition of centres to provide more robust investigations into this topic. METHODS: High-volume aortic arch centres were identified from the literature and contacted for recruitment. A Research Steering Committee of expert arch surgeons was convened to oversee the direction of the research. RESULTS: The International Aortic Arch Surgery Study Group has been formed by 41 arch surgeons from 10 countries to better evaluate patient outcomes after aortic arch surgery. Several projects, including the establishment of a multi-institutional retrospective database, randomized controlled trials and a prospectively collected database, are currently underway. CONCLUSIONS: Such a collaborative effort will herald a turning point in the surgical management of aortic arch pathologies and will provide better powered analyses to assess the impact of varying surgical techniques on mortality and morbidity, identify predictors for neurological and operative risk, formulate and validate risk predictor models and review long-term survival outcomes and quality-of-life after arch surgery.

Safety and pitfalls in frozen elephant trunk implantation.

The frozen elephant trunk (FET) procedure, or open stent grafting, is a tool for the combined open and endovascular treatment via a median sternotomy of extensive aortic disease involving both aortic arch and descending thoracic aorta. The technique aims to stabilize the maximum extent of the thoracic aorta in one step, with the goal of either rendering a secondary intervention to the downstream aorta unnecessary or producing an easy landing zone for secondary thoracic endovascular aortic repair (TEVAR) or open surgery. Even though large case series have reported good results, we still have no conclusive evidence as to which patients and what kind of pathologies benefit from this technique. The surgical sequences described for total arch replacement with the FET procedure are just as varied as the associated devices and indications. This article focuses on important perioperative and surgical aspects, as well as potential complications during FET procedures.

Bare metal stenting for endovascular exclusion of aortic arch thrombi.

BACKGROUND: Aortic thrombi in the ascending aorta or aortic arch are rare but are associated with a relevant risk of major stroke or distal embolization. Although stent grafting is commonly used as a treatment option in the descending aorta, only a few case reports discuss stenting of the aortic arch for the treatment of a thrombus. The use of bare metal stents in this setting has not yet been described. METHODS: We report two cases of ascending and aortic arch thrombus that were treated by covering the thrombus with an uncovered stent. Both procedures were performed under local anesthesia via a femoral approach. A femoral cutdown was used in one case, and a total percutaneous insertion was possible in the second case. RESULTS: Both procedures were successfully performed without any periprocedural complications. Postoperative recovery was uneventful. In both cases, no late complications or recurrent embolization occurred at midterm follow-up, and control CT angiography at 1 respectively 10 months revealed no stent migration, freely perfused supra-aortic branches, and no thrombus recurrence. CONCLUSION: Treating symptomatic thrombi in the ascending aorta or aortic arch with a bare metal stent is feasible. This technique could constitute a minimally invasive alternative to a surgical intervention or complex endovascular therapy with fenestrated or branched stent grafts.

Thoracic stent graft sizing for frozen elephant trunk repair in acute type A dissection.

OBJECTIVE: Although stenting of the descending aorta simultaneously with proximal aortic repair has become an accepted part of the therapy for acute type A dissection, no general recommendations have been accepted regarding the choice of diameter and length of the stent grafts. The present study explored the safety and effectiveness of sizing the stent graft of the hybrid prosthesis in relation to the total aortic diameter and extending the landing zone to the level of the T10-T12 vertebrae. METHODS: The frozen elephant trunk procedure was performed on 32 patients with acute type A aortic dissection. The stent graft size was chosen according to the total aortic diameter measured on contrast-enhanced computed tomography scans. The stent graft was inserted with the distal landing zone at the level of vertebrae T10-T12. All patients underwent computed tomography or magnetic resonance angiography before discharge; 8 patients underwent subsequent endovascular stent extension. RESULTS: The 30-day survival was 100%, with 3.1% (1/32) overall mortality at 17 ± 4 months (range, 1-33) of follow-up. The postoperative complications included pneumonia in 5, pulmonary embolism in 3, sepsis in 1, and permanent recurrent laryngeal nerve damage in 1 patient. No ischemic brain or spinal cord injury occurred. During follow-up, no endoleaks or false lumen patency developed. CONCLUSIONS: Sizing the stent graft of the hybrid prosthesis according to the total aortic diameter and choosing a distal landing zone between vertebrae T10 and T12 is safe, with low midterm mortality and morbidity. It allows an extensive repair of the dissected aorta with early definite occlusion of the false lumen and prepares for potential endovascular extension of the graft.

Restoration of the thoracic aorta in Type A dissection with hybrid prosthesis.

Following successful repair of Type A dissection, late morbidity and mortality depend on the progression of residual chronic Type B dissection. To avoid the development of late aneurysms of the descending thoracic aorta, a persistent aortic false lumen around the stent-graft can be prevented by remodeling the thoracic aorta. Ten consecutive patients (mean age: 56 years) with acute Type A dissection underwent a "frozen elephant trunk operation" with the E-vita hybrid prosthesis, under deep hypothermic circulatory arrest, between October 2009 and April 2010. The thoracic aorta was restored to its original size. Computed tomography was used to size the aortic diameter. All patients survived and were routinely discharged. Postoperative computed tomography showed no remaining false lumen and no distal organ ischemia in any patient. No new neurological complication was recorded. Two patients suffered postoperative pulmonary arterial embolism; one underwent embolectomy. Restoration of the thoracic aorta is a safe procedure to close the false lumen during the primary operation for acute Type A dissection. However, the diameter of the stent should reflect the overall aortic size, independent of the diameter of the true lumen.