Norihisa Karube

Intramural haematoma should be referred to as thrombosed-type aortic dissection

OBJECTIVESnIntramural haematoma is defined pathologically as aortic dissection without an intimal tear. We therefore believe that this term is inappropriate as an acute clinical diagnosis, and instead, use the term thrombosed-type acute aortic dissection. We compared the features of thrombosed-type acute aortic dissection with those of classic dissection.nnnMETHODSnThrombosed type was defined as aortic dissection without flow in the false lumen of the aorta on contrast-enhanced computed tomography. Surgery was indicated for all cases of type A acute aortic dissection, and central repair operations were performed in 509 patients. We retrospectively studied these patients surgical records.nnnRESULTSnThree hundred and forty-four patients (68%) had classic dissection, and 165 (32%) had thrombosed type. Thrombosed type was associated with a significantly higher mean age (69 vs 60 years, P < 0.01), a higher incidence of cardiac tamponade (45 vs 28%, P < 0.01) and a lower incidence of malperfusion (6 vs 35%, P < 0.01) than classic dissection. Entry tears were located in the ascending aorta and the arch in 74 patients (45%) with thrombosed type. Since 2007, an intimal tear has been confirmed intraoperatively or on computed tomography in 39 (78%) of 50 patients with thrombosed-type aortic dissection. Mortality was significantly lower in patients with thrombosed-type dissection (6%) than in those with classic dissection (13%, P = 0.02).nnnCONCLUSIONSnMost cases of intramural haematoma are acute aortic dissections with an intimal tear without re-entry. Intramural haematoma should be referred to as thrombosed-type acute aortic dissection. Thrombosed type can be easily diagnosed on contrast-enhanced computed tomography and has features distinct from those of classic dissection. Our classification may be useful for the diagnosis of these types of aortic dissection.

Risk analysis and improvement of strategies in patients who have acute type A aortic dissection with coronary artery dissection

OBJECTIVESnTo identify the risk factors for mortality and establish improved treatment strategies in patients who have acute type A aortic dissection with coronary artery dissection.nnnMETHODSnFrom January 1994 through December 2011, we performed surgery in 516 patients with acute type A aortic dissection. We studied 75 (15%) of these patients who had coronary artery dissection. Myocardial ischaemia was present in 48 (64%) of the 75 patients. The culprit coronary artery was the right coronary artery (RCA) in 26 patients, the left coronary artery (LCA) in 19 and the RCA + LCA in 3. For coronary artery reconstruction, preoperative coronary stent placement was done in 7 patients (RCA, 4 and LCA, 3), aortic root replacement in 14, coronary artery bypass grafting in 23 and biological glue application in 28. The relationships of preoperative risk factors and coronary artery reconstruction procedure with in-hospital death and postoperative low cardiac output syndrome (LOS) were analysed using Fishers exact test.nnnRESULTSnHospital death was 18/75 patients (24%), 16/48 (33%) among patients with ischaemia and 2/27 (7.4%) without ischaemia. The culprit lesion involved the RCA in 4/26 patients (15%), the LCA in 9/19 (47%) and the RCA + LCA in 3/3 (100%). Factors related to operative mortality were ischaemia (P = 0.019), LCA territory ischaemia (P = 0.003) and preoperative cardiopulmonary arrest (CPA) (P = 0.013). Postoperative LOS was less common in patients with coronary stent placement (P = 0.042).nnnCONCLUSIONSnIn patients who undergo surgery for acute type A dissection with coronary artery dissection, preoperative CPA and myocardial ischaemia (particularly LCA territory ischaemia) negatively affect survival outcomes. Early revascularization by coronary stent placement is effective in preventing postoperative LOS.

Therapeutic strategy for treating aortoesophageal fistulas

PurposeThe development fistulas between the thoracic aorta and the esophagus are highly fatal conditions. We aimed to identify a therapeutic strategy for treating aortoesophageal fistula (AEF) in this study, by investigating all AEF cases presented in this special symposium at the 65th Annual Scientific Meeting of the Japanese Association for Thoracic Surgery.MethodsForty-seven AEF patients were included in this study. The survivors and nonsurvivors at six and 18xa0months after diagnosis of AEF were classified into “Group A6”, “Group D6”, “Group A18”, and “Group D18”, respectively. Comparisons between Group A6 and Group D6 and between Group A18 and Group D18 were made with regard to therapeutic strategy.ResultsTwenty-two (46.8xa0%) and 33 (70.3xa0%) of the 47 patients died within 6 and 18xa0months, respectively. The patients treated with omentum wrapping (pxa0=xa00.0052), esophagectomy (pxa0=xa00.0269) and a graft replacement strategy for the aorta (pxa0=xa00.002) were more frequently included in Group A6. The patients with the omentum wrapping (pxa0=xa00.0174) and esophagectomy (pxa0=xa00.0203) and graft replacement were more significantly included in Group A18. The results of the multivariate analysis indicated that the mortality rate at 6 and 18xa0months after diagnosis was significantly correlated with graft replacement (pxa0=xa00.0188) and esophagectomy (pxa0=xa00.0257), respectively. There were significant differences in the actuarial survival curves in patients who had omentum wrapping, graft replacement, and esophagectomy compared to patients who did not have these 3 therapeutic procedures.ConclusionThe use of thoracic endovascular aortic repair alone for AEF should not be considered a definitive surgery. In contrast, esophagectomy, open surgery with aortic replacement using prostheses and homografts and greater omentum wrapping significantly improve the mid-term survival of AEF.

Clinical outcomes of emergency surgery for acute type B aortic dissection with rupture

OBJECTIVESnThe purpose of this study was to evaluate the clinical outcomes of emergency surgery for acute type B aortic dissection with rupture and to compare results between open surgery and thoracic endovascular aortic repair (TEVAR).nnnMETHODSnTwo hundred and ninety-four patients with acute type B aortic dissection were admitted to our hospital between January 2000 and March 2012. At presentation, 30 (10%) patients had rupture (20 men, 10 women; mean age, 71 ± 15 years), among whom 23 underwent emergency surgery: 9 underwent TEVAR and 14 underwent open surgery. The objective of TEVAR was closure of the primary entry site and the secondary tear site in the descending thoracic aorta.nnnRESULTSnIn the TEVAR group, technical success was achieved: the primary entry site was closed, and bleeding was controlled in all 9 patients. There was no operative death, and 1 (13%) patient had cerebral infarction. In the open surgery group, 2 (14%) patients died during hospitalization, and 4 (29%) had cerebral infarction in the acute phase. Hospitalization tended to be longer in the open surgery group than in the TEVAR group. The overall survival rate at 1 year was 71 ± 17% in the TEVAR group and 86 ± 9% in the open surgery group (P = 0.89).nnnCONCLUSIONSnTEVAR for acute type B aortic dissection with rupture could be performed with relatively low morbidity and mortality, with no significant difference when compared with open surgery. The main objective of TEVAR for acute type B aortic dissection with rupture is control of bleeding, which can be achieved by closing the primary entry site and the secondary tear site in the descending thoracic aorta. If anatomically feasible and performed immediately, TEVAR is the treatment of choice for acute type B aortic dissection with rupture because it is less invasive than open surgery.

Early reperfusion strategy improves the outcomes of surgery for type A acute aortic dissection with malperfusion

Objective The control of malperfusion is the key to improving the outcomes of surgery for type A acute aortic dissection. We revised our treatment strategy to reperfuse each ischemic organ before central repair. Methods Our current early reperfusion strategy consists of percutaneous coronary artery intervention for coronary malperfusion, direct surgical fenestration for carotid artery occlusion, active perfusion of the superior mesenteric artery for visceral malperfusion, and external shunting from the brachial artery to the femoral artery for lower limb ischemia. Central repair is performed without delay after reperfusion therapy, but if irreversible organ damage is recognized, further aggressive treatment is discontinued. Results Among 438 patients who underwent initial treatment for type A acute aortic dissection, malperfusion in one or more organs was diagnosed in 108 patients (24%). We applied an early reperfusion strategy in 33 patients, (coronary, 14 patients; carotid, 4; visceral, 7; lower extremity, 8). Central repair was then performed in 28 patients. One patient (3.6%) died of pneumonia; 27 patients overcame the ischemic organ damage and survived. Among the 108 patients with malperfusion, 10 patients (9.3%) were treated medically without early reperfusion and central repair. During the same period, mortality from central repair procedures in patients with malperfusion who had not received early reperfusion therapy was 12 of 65 (18%), and the mortality of patients without malperfusion was 9 of 262 (3.4%). Malperfusion was a serious risk factor for hospital death, but the mortality rate of the patients with an early reperfusion strategy was significantly (P < .01) lower than the patients without early reperfusion. Conclusions Our strategy might improve the outcomes of surgery for type A acute aortic dissection with malperfusion. This strategy enables us to avoid unproductive central repair procedures in irreversibly damaged patients.

Evaluation and Influence of Brachiocephalic Branch Re-entry in Patients With Type A Acute Aortic Dissection

BACKGROUNDnStanford type A acute aortic dissection (A-AAD) extends to the brachiocephalic branches in some patients. After ascending aortic replacement, a remaining re-entry tear in the distal brachiocephalic branches may act as an entry and result in a patent false lumen in the aortic arch. However, the effect of brachiocephalic branch re-entry concomitant with A-AAD remains unknown.Methodsu2004andu2004Results:Eighty-five patients with A-AAD who underwent ascending aortic replacement in which both preoperative and postoperative multiple-detector computed tomography (MDCT) scans could be evaluated were retrospectively studied. The presence of a patent false lumen in at least one of the brachiocephalic branches on preoperative MDCT was defined as brachiocephalic branch re-entry, and 41 patients (48%) had this. Postoperatively, 47 of 85 (55%) patients had a patent false lumen in the aortic arch. False lumen remained patent after operation in 34 out of the 41 (83%) patients with brachiocephalic branch re-entry, as compared to that in 13 of the 44 (30%) patients without such re-entry (P<0.001). Brachiocephalic branch re-entry was a significant risk factor for a late increase in the aortic arch diameter greater than 10 mm (P=0.047).nnnCONCLUSIONSnBrachiocephalic branch re-entry in patients with A-AAD is related to a patent false lumen in the aortic arch early after ascending aortic replacement and is a risk factor for late aortic arch enlargement.

Impact of preoperative dual antiplatelet therapy on bleeding complications in patients with acute coronary syndromes who undergo urgent coronary artery bypass grafting

BACKGROUNDnA 5- to 7-day washout period before coronary artery bypass grafting (CABG) is recommended for patients who have recently received a thienopyridine derivative; however, data supporting this guideline recommendation are lacking in Japanese patients.nnnMETHODSnUrgent isolated CABG was performed in 130 consecutive patients with acute coronary syndromes (ACS) (101 men; mean age, 69 years). Urgent CABG was defined as operation performed within 5 days after coronary angiography. All patients continued to receive aspirin 100mg/day. The subjects were retrospectively divided into 2 groups: 30 patients with preoperative thienopyridine (clopidogrel in 15 patients, ticlopidine in 15) exposure within 5 days [dual antiplatelet therapy (DAPT) group] and 100 patients without exposure [single antiplatelet therapy (SAPT) group].nnnRESULTSnAlthough the DAPT group had a higher proportion of patients who received perioperative platelet transfusions than the SAPT group (50% vs. 18%, p<0.001), intraoperative bleeding (median, 1100ml; interquartile range, 620-1440 vs. 920ml; 500-1100) and total drain output within 48h after surgery (577±262 vs. 543±277ml) were similar. CABG-related major bleeding, which was defined as type 4 or 5 bleeding according to the Bleeding Academic Research Consortium definitions, occurred in a significantly higher proportion of patients in the DAPT group than in the SAPT group (20% vs. 3%, p=0.005). This difference in major bleeding was driven mainly by the higher rate of transfusion of ≥5U red blood cells within a 48-h period in the DAPT group (13% vs. 1%, p=0.01). There was no significant difference in the 30-day composite endpoint including death, myocardial (re)infarction, ischemic stroke, and refractory angina between the DAPT group and SAPT group (17% vs. 19%).nnnCONCLUSIONSnPreoperative DAPT increases the risk of CABG-related major bleeding in Japanese patients with ACS undergoing urgent CABG.

Pitfalls for the “Sandwich technique” via a right ventricular incision to repair post-infarction ventricular septal defects

BackgroundWe have reported “sandwich technique,” via a right ventricular incision, to treat a post-infarction ventricular septal defect (VSD). This technique involves the placement of patches on both the left and right sides of the septum, pinching the VSD sealed with surgical adhesive between the two patches. In this study, we analyzed factors influencing 1-year mortality to determine the pitfalls in our procedure.MethodsWe evaluated 24 consecutive patients with post-infarction VSD who underwent the “sandwich technique” via a right ventricular incision. One-year survival and major residual leak were used as the criteria for the analysis of survival and technical success, respectively. In protocol 1, clinical variables were evaluated as predictors of one-year mortality. In protocol 2, surgical techniques were evaluated as predictors of major residual leak, which was found to be related to one-year mortality in protocol 1.ResultsIn protocol 1, the one-year mortality was higher in patients with major residual leak (75xa0%, 3/4) than in those without (15xa0%, 3/20) (pxa0=xa00.035). In protocol 2, the patients with major residual leak had smaller patches than those without (41.9xa0±xa03.8 vs. 47.8xa0±xa04.8xa0mm, pxa0=xa00.031) and a smaller size difference between the patches and the VSD (22.5xa0±xa06.5 vs. 30.0xa0±xa05.7xa0mm, pxa0=xa00.028).ConclusionFor the “sandwich technique” via a right ventricular approach to treat post-infarction VSD, the choice of patch size according to VSD size is an important variable for reducing major residual leak.

“Pouch Technique” Makes Proximal Anastomosis of Free Internal Thoracic Artery Graft to Ascending Aorta Easy and Safe in Coronary Artery Bypass Surgery

PURPOSEnThe proximal anastomosis of free right internal thoracic artery to ascending aorta is technically difficult when the caliber is not enough.nnnMETHODSnWe incise the proximal stump of the graft longitudinally for 10 mm. One side of start point of longitudinal incision is sewn to the end point of incision by 7-0 polypropylene. The folded sideline (5 mm length) is then closed with a running suture, then formation of pouch like anastomotic end is accomplished.nnnRESULTSnWe used this technique in consecutive 34 patients who underwent coronary artery bypass surgery including revascularization to circumflex arteries. Postoperative angiography revealed 97% patency. It does not need another graft material like saphenous vein or radial artery, and possible not only in on pump surgery but also in off pump.nnnCONCLUSIONnThis new Pouch technique will make it easy to use right internal thoracic artery as a free graft in coronary artery bypass surgery.