Masatsugu Kuraoka

Frozen elephant trunk technique and partial remodeling for acute type A aortic dissection

OBJECTIVE The aimed to describe the frozen elephant trunk (FET) technique and partial remodeling (PR) for acute type A aortic dissection (ATAAD), considering the long-term prognosis on the basis of our 13 years of experience. METHODS There were 80 consecutive patients (mean age: 66.4 years) with an FET and PR technique for ATAAD between September 1997 and February 2010. We indicated a PR for all 80 patients without dilatation of the sinuses and a FET for 20 patients with a distal entry in the descending aorta, 14 patients with a dilatation more than 4cm on the distal arch and 46 patients with a narrow true lumen younger than 70 years with a narrow true lumen. During moderate hypothermic circulation with selective cerebral perfusion and distal perfusion from the femoral artery, a stent graft (mean diameter: 27.7mm, mean length: 9.9mm, mean distal depth: thoracic vertebra (Th) 6.0th) was inserted through the transected proximal aortic arch. The plication of the sinotubular junction (N=42) or partial remodeling for right and/or non-coronary cusp (N=38) was performed after total arch replacement with a four-branched prosthesis. RESULTS Four patients died in hospital. Early morbidity included two (2.5%) strokes but no spinal cord injury. In long-term follow-up (mean 94.6 months), five patients died of non-aortic events and two re-operations (Bentall and stent grafting to the descending aorta) were required. No patients had patent false lumen on the stent graft and residual aortic regurgitation, according to late follow-up computed tomography (CT) and echogram. The 10-year survival was 75% and the overall 10-year re-operation free rate on the thoracic aorta was 95%. CONCLUSION FET and modified PR techniques could be effective for improving the long-term outcome on the distal and proximal aorta in an ATAAD.

Long-term results of the frozen elephant trunk technique for the extensive arteriosclerotic aneurysm

OBJECTIVES The objective of this report is to elucidate the feasibility of the frozen elephant trunk technique as a one-stage operation for extensive arteriosclerotic aneurysms and to investigate the long-term durability and efficacy of this procedure from our 11 years of experience. METHODS The subjects were 58 consecutive patients who electively received the frozen elephant trunk technique for arteriosclerotic aneurysms involving the aortic arch and the descending aorta between September 1997 and September 2008. Concomitant procedures included 15 coronary artery bypass grafts, 2 aortic valve replacements, 1 aortic root replacement, and 3 maze procedures. The stent graft was delivered to the seventh thoracic vertebra level (Th7) in 22, Th8 in 26, Th9 in 8, and Th10 in 2 patients. Cerebrospinal fluid drainage was administered preoperatively in 10 (17.2%) patients. RESULTS Operative mortality within 30 days was 0 of 58. There was 1 in-hospital death. Perioperative morbidity included strokes and spinal cord injury in 2 (3.4%) patients each. During the mean follow-up period of 54.2 +/- 36.9 months, there were 9 (15.5%) late deaths, and 7 (12.1%) patients required additional intervention. The 8-year survival was 65.5%, the overall 8-year aortic event free survival was 72.8%, and the 8-year event free survival on the site of the stent graft was 94.8%. A follow-up computed tomographic image was available for 86.2% (50/58) of patients who survived longer than 6 months. The size of the aneurysm increased in 1 (2.0%) patient, was not changed in 6 (12.0%) patients, shrank in 34 (68.0%) patients, and was obliterated in 9 (18.0%) patients. CONCLUSIONS The frozen elephant trunk for extensive aortic aneurysms had long-term durability and efficacy and might become the alternative treatment for extended aortic replacement.

Long-term results of the frozen elephant trunk technique for extended aortic arch disease

OBJECTIVES This study describes the long-term safety and effectiveness of extended aortic arch replacement with the frozen elephant trunk technique from our 12 years of experience. METHODS Between September 1997 and September 2008, 156 patients (mean age 67.9 years) with different pathologies from the aortic arch to the extended descending aorta in 100 dissections (acute A/acute B/chronic B=66/26/8) and 56 thoracic arteriosclerotic aneurysms (TAAs) had the frozen elephant technique performed upon them. During moderate hypothermic circulation with selective cerebral perfusion, the stent graft was inserted through the transected proximal aortic arch with trans-oesophageal echo guidance. RESULTS Six patients (3.2%) (acute A/acute B/chronic B/TAA=3/2/0/1) died in hospital. Postoperative morbidity induced four (2.6%) strokes (acute A/acute B/chronic B/TAA=2/0/0/2) and three (2.0%) spinal injuries (paraplegia in two and transient paraparesis in one) (acute A/acute B/chronic B/TAA=0/0/1/2). In the long-term follow-up (mean 63.3 + or - 39.2 months, maximum 144 months) 16 patients died. The survival rate was 99.3%, 86.5% and 74.9% at 1, 5 and 10 years, respectively. An additional operation was performed in 15 (9.4%) (ascending aorta/aortic root/descending aorta/abdominal aorta=1/2/5/7) including three stent-graft-related events (2.1%), and the additional repair proved successful. A follow-up computed tomography (CT) image was available for 96.0% (143/149) of patients who survived longer than 12 months. The size of false lumen or aneurysm increased in four patients, was unchanged in 20 patients (14.0%), shrank in 66 (46.2%) and was completely obliterated in 55 (37.1%). CONCLUSIONS The frozen elephant technique could be an attractive treatment for extended aortic arch disease to the extended descending aorta for acute aortic dissection as well as arteriosclerotic aneurysm.

Surgical strategies for organ malperfusions in acute type B aortic dissection

This study is retrospectively to evaluate strategies for organ malperfusion on the view point of two mechanisms (true lumen collapse in the aorta=Ao type, or branch dissection=Br type) in acute type B aortic dissection. There were 16 of Ao type and 4 of Br type in 20 patients with organ malperfusion. In Ao type, we performed entry closure in 12 patients, surgical bypass grafting in two to superior mesenteric artery (SMA) in one and femoral artery in two, and surgical fenestration in two. In Br type, we performed interventional non-covered stenting to the orifice of visceral arteries in two patients, surgical bypass to SMA with ileum resection in one, and surgical bypass to SAM and renal arteries in one. Five patients in 16 of Ao type died within 30 days that had two multiple organ failure after entry closure, one aortic injury during endovascular stent graft repair, two more multiple organ failure after femoral bypass, however, all four patients in Br type were rescued. Central aortic operation to true lumen collapse with entry closure for Ao type ischemia and organ reperfusion with extra-anatomical bypass or non-covered stent to ischemic arteries for Br type ischemia should be performed before catastrophic status.

Identification of Dab2 and Intelectin-1 as Novel Positive Immunohistochemical Markers of Epithelioid Mesothelioma by Transcriptome Microarray Analysis for Its Differentiation From Pulmonary Adenocarcinoma

As there are currently no absolute immunohistochemical positive markers for the definite diagnosis of malignant epithelioid mesothelioma, the identification of additional “positive” markers that may facilitate this diagnosis becomes of clinical importance. Therefore, the aim of this study was to identify novel positive markers of malignant mesothelioma. Whole genome gene expression analysis was performed using RNA extracted from formalin-fixed paraffin-embedded tissue sections of epithelioid mesothelioma and pulmonary adenocarcinoma. Gene expression analysis revealed that disabled homolog 2 (DAB2) and Intelectin-1 had significantly higher expression in epithelioid mesothelioma compared with that in pulmonary adenocarcinoma. The increased mRNA expression of DAB2 and Intelectin-1 was validated by reverse transcriptase polymerase chain reaction of RNA from tumor tissue and protein expression was validated by Western blotting of 5 mesothelioma cell lines. The utility of DAB2 and Intelectin-1 in the differential diagnosis of epithelioid mesothelioma and pulmonary adenocarcinoma was examined by an immunohistochemical study of 75 cases of epithelioid mesothelioma and 67 cases of pulmonary adenocarcinoma. The positive rates of DAB2 and Intelectin-1 expression in epithelioid mesothelioma were 80.0% and 76.0%, respectively, and 3.0% and 0%, respectively, in pulmonary adenocarcinoma. Immunohistochemically, the sensitivity and specificity of DAB2 was 80% and 97% and those of Intelectin-1 were 76% and 100% for differentiation of epithelioid mesothelioma from pulmonary adenocarcinoma. In conclusion, DAB2 and Intelectin-1 are newly identified positive markers of mesothelioma and have potential to be included in future immunohistochemical marker panels for differentiation of epithelioid mesothelioma from pulmonary adenocarcinoma.

Early entry closure for acute type B aortic dissection by open stent grafting

PurposeWe describe the long-term efficacy of early entry closure for acute type B aortic dissection by open stent grafting based on long-term results and changes in the false lumen on enhanced computed tomography (CT).MethodsWe performed open stent grafting for acute type B aortic dissection in 28 28 patients between 1998 a 2008. They included 14 patients with complicated type B aortic dissection (11 patients with limb and/or visceral ischemia and 4 patients with impending rupture). Uncomplicated type B aortic dissection was present in 14 patients, including 4 patients with an ulcer-like projection and 10 patients who had stable dissection with a patent false lumen.ResultsTwo patients who had the ischemic type died within 30 days. Postoperative complications occurred in two patients, including one case of paraplegia and one of mediastinitis. Two more deaths occurred during a median follow-up period of 45 months (range 6–114 months), with one related to open stent-graft infection and one due to pneumonia. The overall survival rate 5 years after open stent grafting was 77%. According to follow-up by CT, the false lumen was completely thrombosed and obliterated in all 26 patients with stent grafts.ConclusionEarly entry closure for both complicated and uncomplicated acute type B aortic dissection with an open stent graft has an acceptable early outcome and provides a high aortic remodeling rate.

One-stage total thoracic aortic repair for mega-aorta using frozen elephant trunk technique

We report the case of a 71-year-old female with mega-aorta extending from the ascending aorta to the descending aorta, who was successfully treated with a one-stage total thoracic aortic repair by the frozen elephant trunk technique using a stent-graft. We used a home-made frozen elephant trunk with four giant-turco Z-stents on the distal side that was inserted into the downstream descending aorta via an aortic arch guiding pull-through wire. The stent-graft was distally positioned at the level of the 12th thoracic vertebra after total arch replacement had been performed using a four-branch graft. The postoperative course was good, and there was no paraplegia or other complications. A postoperative computed tomography scan demonstrated complete thrombosis of the descending thoracic aneurysm without endoleak. In conclusion, the frozen elephant trunk was effective as a one-stage operation for mega-aorta.