Tomohiko Sakamoto

The efficacy and short-term results of hybrid thoracic endovascular repair into the ascending aorta for aortic arch pathologies.

OBJECTIVES Conventional total aortic arch repair is a high-risk procedure, particularly for high-risk patients. Although endovascular treatment of aortic arch aneurysm is a recently induced procedure, only a few cases are indicated and outcomes are questionable. Here, we report on the early and short-term results of our surgical procedure, i.e. hybrid arch repair with supra-aortic debranching and endografting into the ascending aorta. METHODS Of the 514 patients who underwent arch repairs from 1997 to March 2012, 40 (28 males; mean age 74.4 years) were high-risk patients for whom hybrid arch repair of the ascending aortic landing zone was performed. Aortic pathologies included 31 degenerative aneurysms (including two ruptures), three type A dissections and four type B dissections. We performed supra-aortic debranching from the ascending aorta and endografting into the ascending aorta in 28 patients (including 10 patients with graft replacements and 3 patients with banding of the ascending aorta). For the 12 patients with an ascending aorta diameter of <36 mm, the chimney graft technique into the innominate artery was performed. RESULTS The 30-day mortality rate was 3%. Postoperative complications were as follows: stroke (0 patient), haemodialysis (1), prolonged mechanical ventilation (2) and spinal cord ischaemia (1). There were one early type I and two type II endoleaks. The mean follow-up duration was 15.5 months, during which freedom from aorta-related death and aortic events were 91 and 89% at 3 years. CONCLUSIONS We achieved satisfactory early and short-term results with hybrid arch repair into the ascending aorta. Our findings suggest that hybrid repair into the ascending aorta may be a viable option for high-risk patients with aortic arch pathologies.

Aortic Remodeling as a Prognostic Factor for Late Aortic Events After Thoracic Endovascular Aortic Repair in Type B Aortic Dissection With Patent False Lumen

Purpose: To assess the significance of aortic remodeling in the prevention of the late aortic events after thoracic endovascular aortic repair (TEVAR) for aortic dissection. Methods: The study involved 52 patients (41 men; mean age was 59.7±13.3 years) with type B aortic dissections and patent false lumens treated with TEVAR between 2004 and 2011. Of the 52 patients, 18 were treated in the acute phase for rupture (n=1), malperfusion (n=10), aortic diameter over 40 mm at onset (n=3), and rapid enlargement of the false lumen (n=4). In the chronic setting, the indications for TEVAR were rupture (n=1), malperfusion (n=2), aortic diameter >50 mm (n=18), and rapid enlargement of the false lumen (n=13). Aortic remodeling was evaluated at 6 months postoperatively, and risk factors for late aortic events were evaluated in multivariate analysis using aortic remodeling and other pre-, peri-, and postoperative factors. Results: Over a mean 36.0±18.9 months, 19 aortic events were documented: enlargement of the false lumen (n=4), type I endoleak (n=2), and erosion at the stent-graft edges (n=13). Multivariate analysis revealed that failure to achieve aortic remodeling at 6 months postoperatively was the only significant risk factor for late aortic events (hazard ratio 0.20, p=0.037). Patients with aortic remodeling had a higher rate of freedom from aortic events compared with those without aortic remodeling (100% vs. 81.5% at 1 year and 79.3% vs. 48.4% at 3 years, respectively). Conclusion: Aortic remodeling after TEVAR is a significant prognostic factor for better long-term results for type B aortic dissection.

Acute onset of paraplegia after repair of abdominal aortic aneurysm in a patient with acute type B aortic dissection

We report a rare complication of acute onset paraplegia after repair of an abdominal aortic aneurysm in a patient with acute type B aortic dissection. A 53-year-old man, suffering from abdominal aortic aneurysm (AAA), was admitted to our hospital with type IIIB acute aortic dissection. Ten days after admission, emergency Y-grafting was performed for impending rupture of the AAA. Twenty hours after Y-grafting, weakness of his lower extremities developed and progressed to paraplegia. Enhanced computed tomography scan revealed expansion of a thrombosed false lumen at the thoracoabdominal aorta, resulting in complete obstruction of the true lumen below the infra-renal aorta. Immediate axillobifemoral bypass was performed to prevent lower limb ischemia. Voluntary movement recovered gradually in both legs and eventually the patient could walk independently.

Thoracic endovascular aortic repair for degenerative distal arch aneurysm can be used as a standard procedure in high-risk patients

OBJECTIVES In recent years, supra-aortic rerouting and thoracic endovascular aortic repair (TEVAR) for treating aortic arch pathology have emerged as a less invasive option for high-risk patients. This study aimed to assess our strategy for preventing stroke and improving late outcomes after supra-aortic rerouting and TEVAR. METHODS Between July 2008 and July 2015, we performed 280 cases of TEVAR for arch pathologies, using manufactured stent grafts. This study reviewed 101 patients who underwent supra-aortic rerouting and TEVAR for degenerative distal arch aneurysms (80 men, mean age 73.1 years, Zone 1/Zone 2 = 48/53). Since 2011, we have routinely used the brain protection method, which comprises blocking native forward flow from the left common carotid artery (LCA) and left subclavian artery (LSA) for zone 1 cases and the LSA for zone 2 cases before TEVAR. RESULTS The mean operation time was 178 ± 65 min. The stroke and 30-day death rates were 3 and 1%, respectively. Before the brain protection method was introduced, the perioperative risk factor for stroke was atheroma Grade ≥III (P = 0.035). Proximal landing zone (P = 0.58) and LSA sacrifice (P = 1.00) were not risk factors for stroke. No strokes occurred after using the brain protection method (before protection: 6% and after protection: 0%). Regarding late results, the rate of freedom from aorta-related death at 1 and 4 years was 97 and 95%, respectively. The rate of freedom from aortic events at 1 and 4 years was 91 and 86%, respectively. During follow-up, no type Ia endoleak developed and one type A dissection was observed. CONCLUSIONS Our strategy for supra-aortic rerouting and TEVAR showed satisfactory early and late results. The chief risk factor for perioperative stroke was atheroma, and blocking native forward flow from the LCA and the LSA prior to the TEVAR procedure helped prevent stroke.

The assessment of collateral communication after hybrid repair for Crawford extent II thoraco-abdominal aortic aneurysms

OBJECTIVES The repair of extensive thoraco-abdominal aortic aneurysms (TAAAs) is invasive and carries a high risk for spinal cord injury (SCI). The aim of this study was to assess the early results and collateral circulation to the spinal cord after hybrid repair for Crawford extent II aortic aneurysms. METHODS Between 1997 and 2013, we performed 128 thoracic endovascular aortic repair (TEVAR) procedures for TAAAs. This study reviews 12 patients who underwent hybrid TEVAR for a Crawford extent II aortic aneurysm (mean age: 56 years, 6 men, chronic dissection: 10). Aortic arch repair was performed to create a proximal landing zone and visceral debranching bypass was performed to create a distal landing zone at separate stages prior to TEVAR. Subsequently, a stent graft was deployed to cover the residual downstream aorta. TEVAR was generally performed the day after the final debranching procedure. Cerebrospinal fluid drainage was performed, and the mean blood pressure was maintained at >90 mmHg in all cases. RESULTS The median operation time for TEVAR was 94 min (range: 71-421 min) and the mean blood loss was 300 ml (range: 130-1350 ml). No SCI or in-hospital death was observed after TEVAR. Multidetector computed tomography identified three arteries (subclavian artery, external iliac artery and internal iliac artery) providing collateral circulation to spinal segmental arteries (SAs). In all cases, mid-thoracic SAs (Th5-8) and low lumbar SAs (L2-5) were fed by the subclavian artery and the internal iliac artery, respectively. Additionally, low thoracic to high lumbar SAs (Th9-L1) communicated with the subclavian artery via the lateral thoracic wall and/or the external iliac artery via the abdominal wall. CONCLUSIONS We achieved satisfactory early and mid-term outcomes with hybrid repair for Crawford extent II TAAAs. Furthermore, collateral circulation to SAs was maintained during and after TEVAR regardless of the extent of the aortic repair.

Closure of the Left Main Trunk of the Coronary Artery and Total Arch Replacement in Acute Type A Dissection During Coronary Angiography

A 64-year-old woman was complicated with acute type A dissection arising from the left main trunk during percutaneous coronary angiography. As the extent of dissection was localized in the ascending aorta, a bare-metal stent was inserted into the left main trunk to cover the entry of dissection. Two days after an angiography, the patients hemodynamic status suddenly deteriorated. A computed tomographic scan showed expansion of a thrombosed false lumen severely compressing the true lumen. Emergency total arch replacement was performed, combined with ligation of the left main trunk and coronary artery bypass grafting. The patient recovered well without residual dissection in the sinus of Valsalva.

Expanded polytetrafluoroethylene-valved conduit with bulging sinuses for right ventricular outflow tract reconstruction in adults

PurposeGenerally, right ventricular outflow tract reconstruction in adults is performed using homografts or xenograft. However, sufficient graft material is difficult to obtain and has the problems of calcification and structure destruction. We, therefore, evaluated using expanded polytetrafluoroethylene- (ePTFE)-valved conduits with bulging sinuses for right ventricular outflow tract reconstruction in adults.MethodsBetween February 2006 and April 2008, a total of five patients (three men, two women), ages 25–51 years old (mean ± SD, 40 ± 11 years)] underwent right ventricular outflow tract (RVOT) reconstruction in our institution. In three patients, RVOT reconstruction was performed with the Ross procedure; and in all cases, tricuspid ePTFE (valved conduits with bulging sinuses were used. The diameter of the conduit was determined according to the RVOT size. Valve function was followed up using echocardiography after surgery and during the early/mid-term periods of recovery (13 months to 3.0 years).ResultsNo morbidity occurred, and no patient required further surgery during the follow-up period. During these follow-up periods, pulmonary observation revealed that no patients had stenosis; regurgitation was mild in one patient and trivial in four patients. In regard to the tricuspid valve, regurgitation was trivial in four patients and mild in one patient.ConclusionAlthough long-term follow-up is required to confirm the durability of the ePTFE-valved conduit with bulging sinuses, the present results indicate a satisfactory result in patients who undergo RVOT reconstruction, even in adult cases.

A novel method for prevention of stent graft-induced distal re-dissection after thoracic endovascular aortic repair for Type B aortic dissection

OBJECTIVES Stent graft-induced distal re-dissection (SIDR) is a burdensome complication after thoracic endovascular aortic repair (TEVAR) for Type B aortic dissection. We developed a novel method to prevent SIDR by placing a small-diameter short stent graft [Excluder Aortic Extender (Cuff)] at the distal landing zone (DLZ) and reviewed its effectiveness in this study. METHODS Ninety patients who underwent TEVAR for Type B aortic dissection using commercially available devices between January 2008 and September 2016 were retrospectively reviewed. Among them, TEVAR with the Cuff technique was performed in 36 (40%) cases, in which a Cuff was placed at the DLZ in the descending aorta prior to the main stent graft deployment to avoid excessive stent graft oversizing at the distal end. The effectiveness of the Cuff technique was assessed by evaluating mid-term clinical results, including the incidence of SIDR. RESULTS Technical success was achieved in all 90 cases. During a median follow-up time of 40.4 months (range 0.2-90.6 months), 8 SIDRs were documented using multidetector computed tomography images. Freedom from SIDR was significantly lower in the Cuff group (Cuff: 100%/5 years vs non-Cuff: 84.6%/5 years; P = 0.04), whereas no difference was observed between both groups in the oversizing rate at the DLZ (19.9 ± 8.5% vs 17.8 ± 9.9%; P = 0.29). CONCLUSIONS Placement of a small-diameter short stent graft at the DLZ (Cuff technique) in TEVAR for aortic dissection is an easy procedure that may reduce the incidence of SIDR.

Type 1a endoleak following Zone 1 and Zone 2 thoracic endovascular aortic repair: effect of bird-beak configuration†

OBJECTIVES Type 1a endoleak is one of the most severe complications after thoracic endovascular aortic repair (TEVAR), because it carries the risk of aortic rupture. The association between bird‐beak configuration and Type 1a endoleak remains unclear. The purpose of this study was to analyse the predictors of Type 1a endoleak following Zone 1 and Zone 2 TEVAR, with a particular focus on the effect of bird‐beak configuration. METHODS From April 2008 to July 2015, 105 patients (mean age 68.6 years) who underwent Zone 1 and 2 landing TEVAR were enrolled, with a mean follow‐up period of 4.3 years. The patients were categorized into 2 groups, according to the presence (Group B, n = 32) or the absence (Group N, n = 73) of bird‐beak configuration on the first postoperative multidetector computed tomography. RESULTS The Kaplan‐Meier event‐free rate curve showed that Type 1a endoleak and bird‐beak progression occurred less frequently in Group N than in Group B. Five‐year freedom from Type 1a endoleak rates were 79.7% and 100% for Groups B and N, respectively (P = 0.007). Multivariable logistic regression analysis showed that dissecting aortic aneurysm (odds ratio 3.72, 95% confidence interval 1.30‐11.0; P = 0.014) and shorter radius of inner curvature (odds ratio 1.09, 95% confidence interval 0.85‐0.99; P = 0.025) were significant risk factors for bird‐beak configuration. Multivariable Cox proportional hazard regression showed that Z‐type stent graft (hazard ratio 2.69, 95% confidence interval 1.11‐6.51; P = 0.030) was a significant risk factor for bird‐beak progression. CONCLUSIONS Appropriate stent grafts need to be chosen carefully to prevent Type 1a endoleak and bird‐beak configuration after landing Zone 1 and 2 TEVAR. Patients with bird‐beak configuration on early postoperative multidetector computed tomography require closer follow‐up to screen for Type 1a endoleak.

An approach to mitral valve surgery by a T-shaped mini-sternotomy with functioning bilateral internal thoracic artery grafts.

We herein report successful surgical treatment of mitral valve regurgitation in a 49-year-old man. He was admitted to our hospital due to acute aggravation of dyspnea on effort. He had a surgical history of coronary artery bypass grafting with bilateral internal thoracic artery grafts. A transthoracic echocardiogram showed severely decreased cardiac function and severe mitral regurgitation due to anterolateral mitral valve leaflet prolapse. Computed tomography showed the right internal thoracic artery running over the front of the aorta to the left circumflex artery. To avoid injury to the functioning grafts during median sternotomy, we chose to perform an inferior T-shaped mini-sternotomy. The surgical field was sufficient to perform mitral valve replacement with a mechanical prosthetic valve under fibrillatory arrest. The grafts were neither dissected nor clamped, and access to the aorta and mitral valve was excellent.