Clinical results of implantation of an endovascular covered stent-graft via midsternotomy for distal aortic arch aneurysm

Aortic arch replacement with frozen elephant trunk technique - a single-center study

BACKGROUND

The frozen elephant trunk (FET) technique was developed to facilitate the two-stage surgery of extensive pathologies of the thoracic aorta and is now routinely applied in acute and chronic aortic syndromes.

METHODS

From 11/2006 to 07/2017, 68 patients underwent aortic arch repair using the FET technique. Patients received either the Jotec E-vita Open graft (n = 57) or the Vascutek Thoraflex hybrid prosthesis (n = 11). Both, group 1 (acute aortic dissection type A and B; symptomatic penetrating aortic ulcer) and group 2 (aortic aneurysm; chronic aortic dissection) included 34 patients each.

RESULTS

Early mortality was 13.2% (14.7% in group 1 vs. 11.7% in group 2, p = 0.720). Neurological complications occurred in 12 patients (17.6%) (stroke: 8.8 vs. 11.7%; p = 0.797 and spinal cord injury: 8.8 vs. 5.9%; p = 0.642 in groups 1 vs. 2 respectively). Cardiopulmonary bypass time and cross clamp time were significantly longer in group 1 (252.2 ± 73.5 and 148.3 ± 34 min vs. 189.2 ± 47.8 and 116.3 ± 34.5 min; p <  0.001). The overall 1-, 3- and 7-year-survival was 80.9, 80.9 and 74.2% with no significant differences between groups 1 and 2. Expansion of true lumen after FET implantation was significant at all levels in both groups for patients with aortic dissection. One-, 3-, and 7-year-freedom from secondary (re-)intervention for patients for aortic dissection was 96.9, 90.2 and 82.7% with no significant differences between groups 1 and 2; p = 0.575.

CONCLUSION

The FET technique can be applied in acute aortic syndromes with similar risks regarding adverse events or mortality when compared to chronic degenerative aortic disease. Postoperative increase in true lumen diameter mirrors decrease of false lumen diameter, goes along with favorable midterm outcome and prolongs freedom from secondary interventions in acute aortic dissection.

Experimental evaluation of homemade distal stent graft fenestration for thoracic endovascular aortic repair of type A dissection by a transapical approach

OBJECTIVE

The use of off-the-shelf stent grafts for thoracic endovascular aortic repair of type A dissections is limited by variability in both the length of the ascending aorta and the location of the proximal intimal tear. This experimental study aimed to assess the feasibility of using a physician-modified thoracic aortic stent graft to treat acute type A dissection by a transapical cardiac approach.

METHODS

The experiments were performed on six cadaveric human heart, ascending aorta, aortic arch, and descending aorta specimens. Fenestration was fashioned in each standard tubular Valiant thoracic stent graft (Valiant Captivia; Medtronic Vascular, Santa Rosa, Calif) to match the anatomy of each specimen. Stent grafts of sufficient length were selected to cover the entire ascending aorta and aortic arch. Stent graft diameters in proximal sealing zones were oversized by 5% to 10%. The length of the fenestration was the distance between the left subclavian artery and the proximal edge of the origin of the brachiocephalic trunk with an additional 10 mm. The diameter of the scallop was that of the brachiocephalic trunk with an additional 5 mm on all sides. The length of the covered portion of the stent graft was the distance between coronary arteries and the proximal edge of the origin of the brachiocephalic trunk. Two lateral radiopaque markers were positioned to delineate the distal and lateral edge of the scallop. Another 3-cm radiopaque marker was sutured onto the sheath to ensure accurate radiologic positioning of the scallop on the outer curve of the aorta. The left ventricle and the thoracic aorta were connected to a benchtop aortic pulsatile flow model. A 5-mm 30-degree lens was introduced through the left subclavian artery to monitor the procedure. The customized stent graft was deployed by a transapical approach under fluoroscopic control.

RESULTS

Median duration of stent graft modification was 21 minutes (range, 17-40 minutes). All attempts to deploy the homemade proximal scalloped stent graft by a transapical approach were successful. Completion angiography demonstrated patency of the supra-aortic trunks and of the coronary arteries in all cases. Macroscopic evaluation did not identify any deterioration of the customized stent graft.

CONCLUSIONS

The use of physician-modified stent grafts is feasible for thoracic endovascular aortic repair of type A dissection by a transapical approach in this model.

Endovascular Stent Grafting for Aortic Arch Aneurysm in Aortoiliac Occlusive Disease following Aortic Arch Debranching and Aortobifemoral Reconstruction

Treatment of thoracic aortic aneurysms constitutes high mortality and morbidity rates despite improvements in surgery, anesthesia, and technology. Endovascular stent grafting may be an alternative therapy with lower risks when compared with conventional techniques. However, sometimes the branches of the aortic arch may require transport to the proximal segments prior to successful thoracic aortic endovascular stent grafting. Atherosclerosis is accounted among the etiology of both aneurysms and occlusive diseases that can coexist in the same patient. In these situations stent grafting may even be more complicated. In this report, we present the treatment of a 92-year-old patient with aortic arch aneurysm and proximal descending aortic aneurysm. For successful thoracic endovascular stent grafting, the patient needed an alternative route other than the native femoral and iliac arteries for the deployment of the stent graft. In addition, debranching of left carotid and subclavian arteries from the aortic arch was also required for successful exclusion of the thoracic aneurysm.

Aortic Arch and Descending Thoracic Aortic Aneurysms: Experience with Stent Grafting for Second-Stage “Elephant Trunk” Repair

Reconstruction of aortic arch and descending thoracic aortic aneurysms (TAAs) is technically challenging and associated with significant morbidity and mortality. We report our experience with extensive TAAs using a two-stage “elephant trunk” repair, with the second stage completed using an endovascular stent graft (ESG). Over 6 years, 111 patients underwent ESG treatment of TAAs at Mount Sinai Medical Center. Twelve of these patients were referred for ESG placement for the second stage of elephant trunk reconstruction because comorbidities placed them at high risk of open surgical repair. Our database was analyzed for technical and clinical success and perioperative complications. The mean follow-up was 11.8 months (range 1–64 months). Twelve patients (five women and seven men) with a mean age of 69 ± 10 years underwent repair of their distal aortic arch and descending TAAs. These aneurysms included nine atherosclerotic aneurysms, one pseudoaneurysm, and two penetrating atherosclerotic ulcers. Three patients were symptomatic. Stent graft repair was technically successful in 91.7% or 11 of 12 patients. Excessive aortic arch tortuosity resulted in failure to deploy a stent graft in one patient. An antegrade approach through the open elephant trunk was used in two patients with severe iliac occlusive disease. Endoleaks (type 2) were identified in two patients with no aneurysm expansion; however, a 14 mm expansion over 1 year occurred in a patient with no identifiable endoleak. One early mortality occurred in a patient with a ruptured 6 cm infrarenal AAA after successful exclusion of the 8 cm TAA. Second-stage elephant trunk reconstruction of an extensive TAA using an ESG is effective in the short term. Its long-term durability remains to be determined.

Aortic arch replacement with frozen elephant trunk-when not to use it

Current scientific evidence suggests the frozen elephant trunk (FET) technique plays an important role in modern aortic arch repair operations, both for aneurysmal disease and acute aortic dissection. Its use in extended aneurysm is generally therapeutic, aiming for complete exclusion of the diseased descending thoracic aorta. In acute aortic dissection type A, the application of FET is more prophylactic in nature, with the aim of preventing late dilatation of the proximal descending thoracic aorta. This review will present the journey of the elephant trunk from its conception to the current available technology. By tracing the historical evolution of the FET technique and prosthesis development, we explore the challenges and limitations of evidence-based surgical research. We present data from our growing experience in aortic arch reconstruction, the results from our latest 27 patients undergoing the 4-branch FET indicating substantially reduced morbidity and mortality (0%) in this complex patient cohort.

Midterm results for endovascular stent grafts via median sternotomy for distal aortic arch aneurysm

Dislocation or perigraft leakage is a major problem during the follow-up period for endovascular stent graft (EVG) implantation via median sternotomy for distal aortic arch aneurysm. Anchoring sutures have been applied for the prevention of these complications. Here, we evaluate the midterm results and the efficacy of anchoring sutures. There were 21 male and 2 female patients enrolled in the study with an average age of 70 years (59-83). Aneurysm types were 21 true aneurysms (13 fusiform, 8 saccular), 1 chronic dissection, and 1 penetrating aortic ulcer. Total arch replacement was performed in two patients and aortocoronary bypass grafting was combined in four patients. Anchoring sutures to fix the EVG via median sternotomy were applied for 11 recent patients. The average follow-up period was 44 (22-79) months. There were no operative mortalities, but one case of paraplegia, one of stroke, and two of temporary spinal cord dysfunction. Complications related to EVG via median sternotomy occurred in five patients who had not received anchoring sutures, but the 11 patients with anchoring sutures showed no EVG-related complications. A chronic type B dissection revealed impending rupture due to false lumen infection 1 year after operation and repeat surgery was performed. Stent dislocation occurred in four patients, two of whom required repeat surgery via left thoracotomy due to endoleakage 3 and 4 years after surgery. One died from aneurismal rupture 5 years after surgery. One required emergency graft replacement because of graft perforation 5 years after surgery. The proportion of patients free from EVG-related events at 5 years after surgery was 75%. Anchoring sutures (P = 0.0155) and a large aneurysm of more than 80 mm (P = 0.0190) were predictors of late EVG-related complications. There were five late deaths: two were from stroke, one from rupture, one from cancer, and one from multiple organ failure after repeat surgery. EVG shortens postoperative recovery with relatively lower mortality, but spinal cord injury is a complication occurring with a relatively high rate. Patients with large aneurysms are not good candidates for EVG implantation via median sternotomy Anchoring sutures to fix the EVG to the aortic wall should help prevent EVG-related events and improve the durability of EVG.

Endovascular stent grafting of descending thoracic aortic aneurysms

The treatment of descending thoracic aortic aneurysms using endovascular stents is one of the more recent advances in treatment and is receiving increasing attention as it is a less invasive alternative to open surgical repair. Although the technology is still primitive, significant improvements have lately been made in the design and deployment of the endovascular stent-grafts. Aortic stent-grafts were used initially to exclude abdominal, and later thoracic, aortic true and false aneurysms. These prostheses have been increasingly used to treat aneurysms, dissections, and traumatic ruptures of the descending thoracic aorta with good early and mid-term outcomes. Although the long-term outcome of patients with aneurysms of the descending thoracic aorta after stent graft implantation has not been investigated, continued refinement of the endovascular approaches has decreased the need for conventional open thoracic aortic aneurysm repair, especially in patients who are at a high risk for standard surgery because of advanced age or the presence of comorbid diseases. The placement of endoluminal stent-grafts to exclude the dissected or ruptured site of thoracic aortic aneurysms is a technically feasible and relatively safe procedure. With the rapid development of endovascular approaches, the treatment of the descending thoracic aortic aneurysms might alter even more, but an extended follow-up is necessary to determine the longer term outcome. Historical perspectives, advantages, device considerations, complications, and current perspectives of the endovascular stent grafting of the descending thoracic aortic aneurysms are elaborated on.

Mid-term results of an endovascular stent-graft by means of median sternotomy for distal aortic arch aneurysm

Migration and perigraft leakage are major problems after endovascular stent graft (EVG) by means of median sternotomy for distal aortic arch aneurysm. Anchoring sutures have been applied to prevent these problems. We evaluate the mid-term results and the efficacy of anchoring sutures. The operation was performed on 19 men and 2 women with a mean age of 70 years (range, 59-81). The aneurysms were 19 true (12 fusiform, 7 saccular), 1 chronic dissection, and 1 penetrating aortic ulcer. EGVs were implanted by way of the aortic arch under retrograde cerebral perfusion in 13 patients and selective cerebral perfusion in 8. Total arch replacement was performed in 2 patients, and aortocoronary bypass grafting in 4. Anchoring sutures to fix the EVG were applied in 9 patients. The average follow-up period was 28 months (range, 2-56). There were no operative mortalities, but 1 paraplegia, 1 stroke, and 2 cases of temporary spinal cord dysfunction occurred. All aneurysms were thrombosed completely after surgery and reduced in diameter (66.9 +/- 17.4 mm to 57.3 +/- 15.7 mm, p < 0.0001). EVG-related complications arose in 4 patients. A chronic Type B dissection revealed impending rupture because of false lumen infection 1 year after operation, and redo surgery was performed. Migration occurred in 3 patients, all with fusiform aneurysms. One of these had a graft kink 1 year later. Another showed aneurysm enlargement with serous pleural effusion 3 years after operation. The third required redo surgery because of perigraft leakage at 3 years after surgery. There were 2 late deaths caused by stroke. There were no EVG-related complications in the 9 cases in which anchoring sutures were applied and in the 7 cases with saccular aneurysms. No spinal cord dysfunction occurred in 8 cases with low-flow antegrade perfusion by way of both axillary arteries while the aorta was opened. Logistic regression analysis showed significant relevance to complications of large aneurysms, greater than 80 mm in diameter. A large aneurysm tends to give rise to complications involving EVG migration. Anchoring sutures of EVG may prevent EVG-related complications.

Cerebrospinal dysfunction after endovascular stent-grafting via a median sternotomy: the frozen elephant trunk procedure

BACKGROUND

Endovascular stent grafting through a median sternotomy for a distal arch aneurysm (the frozen elephant trunk procedure) is an alternative to synthetic graft replacement. But spinal cord dysfunction can easily occur as a complication after surgery. Although its cause is uncertain, some attempts at prevention have been instituted. We address the mechanism of spinal cord dysfunction and evaluate the efficacy of our preventive measures.

METHODS

There were 22 men and 2 women with an average age of 71 (59 to 83) years. There were 22 true aneurysms (13 fusiform, nine saccular), one chronic dissection, and one penetrating aortic ulcer. The following strategies for prevention of spinal cord dysfunction were utilized: low flow perfusion through both axillary arteries (n = 10); pigtail catheter guidance (n = 19); use of a shorter graft with anchoring sutures (n = 12); flooding of the operative field with carbon dioxide (n = 7); aortic unclamping (n = 7), and use of ultra-thin woven Dacron grafts (n = 15).

RESULTS

There was no operative mortality, but cerebrospinal dysfunction complicated four cases (17%): one paraplegia, one stroke along the basilar artery, and two cases of temporary spinal cord dysfunction (paresthesia of the right leg and urinary disturbance). Cerebrospinal dysfunction tended to occur in fusiform aneurysms (31%, p = 0.044). Except when low flow antegrade perfusion through both the axillary arteries was utilized, which resulted in no cases of paraplegia or paraparesis (p = 0.064), the methods used for prevention of cerebrospinal dysfunction appeared to have little efficacy.

CONCLUSIONS

Cerebrospinal dysfunction is a serious complication of the frozen elephant trunk procedure. Its cause has not been clarified, but it tends to occur in fusiform-type aneurysms. Antegrade perfusion through both axillary arteries while the aorta is open may be helpful in its prevention.

Successful stent-grafting for perforation of the thoracic aorta by an intraaortic balloon pump

Vascular complications associated with intraaortic balloon pump placement are quite common and predominantly related to femoral or iliac damage. Iatrogenic injury of the thoracic aorta is less usual and often fatal. Surgery for the lesions of the descending thoracic aorta still has a relatively high morbidity and mortality. Endovascular covered stentgraft prostheses have become a less invasive therapeutic approach to lesions of the thoracic aorta, especially in patients with high surgical risk. We describe a case of perforation of the thoracic aorta caused by an intraaortic balloon pump. The injury was confirmed by aortography and successfully repaired by implantation of an endovascular stent-graft via the left common iliac artery.