Masaaki Toyama

Stented elephant trunk procedure combined with ascending aorta and arch replacement for acute type A aortic dissection

OBJECTIVES Despite steadily improving outcomes, surgery for acute type A aortic dissection has several unresolved problems such as expansion of the residual false lumen in the descending aorta. We performed transaortic stented graft implantation into the descending aorta combined with the ascending aorta and aortic arch replacement for acute type A aortic dissection. We review the efficacy and outcomes of this procedure with respect to the residual false lumen and postoperative neurologic complications we encountered. METHODS Nine consecutive patients with acute type A aortic dissection underwent this procedure. The stented elephant trunk graft was implanted through the aortic arch under hypothermic circulatory arrest. The stented graft was 15 cm long in six patients, and 10 cm long in three patients. Enhanced computed tomography (CT) was performed 1 month after surgery and once each year after discharge to evaluate the postoperative time course of the residual false lumen. RESULTS Cardiopulmonary bypass (CPB) time was quite long because of slow cooling and re-warming [352+/-92 (mean+/-SD) min], and average lower-body arrest time was 54+/-10min. The intima in one patient was injured at the time of implantation, and a small leak was created. One patient died of multiorgan failure postoperatively. One patient suffered cerebral injury, and two suffered spinal cord injury perioperatively. Average follow-up time was 40.4 months (range, 13-66 months). One patient died of cerebral infarction during follow up, and the other seven survived and remain well. Postoperative enhanced CT scans showed that the dissected descending aortas attached to the stented grafts and the aortas near the stented grafts returned to normal. In one patient with no re-entry, the false lumen completely closed with thrombi and the entire aorta returned to normal. The diameter of the descending aorta decreased or did not change in six of the seven patients (85.8%) and increased by only 2mm in one of them (14.2%) during follow up. CONCLUSIONS Implantation of a stented elephant trunk into the descending aorta combined with replacement of the ascending aorta and total arch for acute type A aortic dissection is effective in closing the residual false lumen of the descending aorta and in preventing expansion of the descending aorta. However, further technical modifications, such as using a short stented elephant trunk, eliminating aortic clamping, shortening CPB and spinal cord ischemic time, and reconstruction of left subclavian artery, are needed to prevent neurologic complications.

Thickened intima of the aortic arch is a risk factor for stroke with coronary artery bypass grafting

BACKGROUND Perioperative stroke is one of the most serious complications of cardiac surgery. METHODS Using transesophageal echocardiography, we estimated the intimal thickness of the thoracic aorta as an index of the severity of aortic atherosclerosis to determine the risk of stroke in coronary artery bypass grafting (CABG) patients. The study population comprised 315 consecutive patients who underwent isolated CABG with cardiopulmonary bypass. RESULTS Five patients (1.6%) had perioperative cerebral stroke or systemic emboli. We compared the mean intimal thicknesses of the ascending aorta, aortic arch, and descending aorta. Mean thicknesses in patients without stroke were 2.07 +/- 0.76, 2.78 +/- 1.15, and 2.32 +/- 1.21 mm, respectively, and mean thicknesses in the stroke patients were 1.94 +/- 0.55, 6.94 +/- 3.79, and 3.39 +/- 1.85 mm, respectively. The patients with an intima of more than 5 mm at the aortic arch had a significantly greater incidence of perioperative stroke (p = 0.007). CONCLUSIONS These results suggest that patients who have an aortic arch intima thickened to more than 5 mm are at a significantly high risk for perioperative stroke, and thus, the CABG procedure should be carefully evaluated to prevent such complications.

Double-patch technique for postinfarction ventricular septal perforation

A modified infarct-exclusion technique for postinfarction ventricular septal perforation is presented. The perforation is closed directly by a small patch next to the conventional patch, and biological glue is applied between the patches to induce stable polymerization. The patch stuck to the infarcted septum, and no residual shunt was observed in any patient because the wide adhesion prevents excessive pressure on the suture line. Seven of 9 patients in whom this method was used had good results. This technique appears suited for repair of ventricular septal perforations, especially those with extensive fresh infarction.

Verapamil and nitroglycerin improves the patency rate of radial artery grafts.

The best way to prevent spasm of the radial artery is still under investigation. We retrospectively compared the effectiveness of topical verapamil-nitroglycerin with papaverine in preventing graft spasm in 215 patients who underwent isolated conventional coronary artery bypass using a radial artery. Postoperative angiographic data were successfully collected in 116 patients. Perioperative radial artery graft spasm was observed in 2 patients in the papaverine group and 1 in the verapamil-nitroglycerin group; this difference was not considered significant. Complete or functional occlusion was detected by postoperative angiography in 13 grafts (10 in the papaverine group and 3 in the verapamil-nitroglycerin group). Multivariate regression analysis revealed that topical papaverine and grafting to the right coronary artery significantly increased the rate of occlusion of radial artery grafts. Although further studies are needed, our data support the view that topical verapamil-nitroglycerin reduces the incidence of radial artery graft occlusion.

Analysis of open heart surgery in patients with liver cirrhosis.

Open heart surgery in patients with liver cirrhosis is considered to be very risky, but the predictors of poor outcomes in such cases have not been established. We report the perioperative results of open heart surgery in patients with liver cirrhosis in our hospital. We reviewed the results of 13 cases in 12 patients with liver cirrhosis who underwent open heart surgery between January 2001 and December 2010. The Child-Turcotte-Pugh classification, the model for end-stage liver disease score, EuroSCORE, and perioperative data were used to identify risk factors for morbidity and mortality retrospectively. Ten patients had postoperative complications. Significant differences in morbidity were evident for Child-Turcotte-Pugh class, cardiopulmonary bypass time, and crossclamp time. Two patients died of liver failure, one at 40 days and the other at 2 years after surgery. Statistically significant differences in liver-related mortality were evident in the model for end-stage liver disease scores and serum cholinesterase levels. We concluded that a high Child-Turcotte-Pugh class was associated with increased morbidity. Cardiopulmonary bypass and crossclamp times were also related to high morbidity, while high model for end-stage liver disease scores and low serum cholinesterase levels predicted liver-related mortality.

Double patch technique for repairing postinfarction ventricular septal defect.

We report 2 cases in which the double patch technique was used to repair an anterior postinfarction ventricular septal defect. To do this, we modified infarct exclusion as follows: In addition to a conventional patch excluding the infarcted muscle, another small patch is used to directly close the septal defect. Gelatin-resorcin-formal glue is applied between the double patches, which prevent the glue from being washed away and enhance it to polymerize stably, thereby rapidly stabilizing the infarcted myocardium with the endocardial patch. Echocardiography immediately after operation showed the infarcted septum had completely adhered to the endocardial patch. Both patients demonstrated satisfactory postoperative hemodynamics. Although 1 patient did well, the other died 6 months postoperatively due to complications of pneumonia and gastrointestinal bleeding secondary to colon carcinoma. This double patch technique appears useful, although further experience is needed to verify its safety and efficacy.

Outcome of composite arterial Y-grafts in off-pump coronary artery bypass

The efficacy of using composite arterial Y-grafts in off-pump coronary artery bypass has not been established. We assessed graft patency, long-term clinical outcomes, and the indications for composite arterial Y-grafting by reviewing 53 patients who underwent primary isolated elective off-pump coronary artery bypass with composite arterial Y-grafts between January 2002 and December 2008. Coronary angiography or 64-slice multidetector computed tomographic coronary angiography was used to assess graft patency. Follow-up raged from 18 to 97 months. The rates of mortality, graft failure, and recurrence of ischemic heart disease were 0%, 22.6%, and 13.2%, respectively. Only 4 (7.5%) patients required additional procedures (percutaneous coronary interventions or repeat surgery) because of graft failure. A significantly higher rate of graft failure was evident when one end of the composite graft was anastomosed to a 75% stenosed branch of a native coronary artery and the other end to a branch with >90% stenosis. The long-term patency of composite arterial Y-grafts in off-pump coronary artery bypass requires proper judgment of the indications.

Transaortic stented graft implantation for aortic arch aneurysm. Its benefits and risk.

OBJECTIVES Despite steady improvements, surgery for aortic arch disease, including the distal arch, continues to result in high rates of morbidity and mortality. We have performed aortic arch repair using a transaortic stented graft implantation into the descending aorta in 8 patients who had true aortic arch aneurysms, and here have reviewed the efficacy and problems from this procedure. METHODS Six patients underwent transaortic stented graft implantation into the descending aorta with bypass to the arch vessels. The other two underwent stented graft implantation into the descending aorta with replacement of the ascending aorta and aortic arch. One patient had a ruptured aneurysm. RESULTS Each operation was performed via a median sternotomy without left thoracotomy. There was no new postoperative occurrence of left recurrent laryngeal nerve palsy. All the five patients without perioperative neurological complication could be extubated within 24 h after surgery. In each case, postoperative enhanced computed tomography scans showed successful thromboexclusion of the aneurysm. There was no endoleak and no graft migration. One patient suffered cerebral injury. Spinal cord injury occurred in 2 patients, and this serious complication may have been caused by prolonged ischemia in the lower body and the long stented graft. CONCLUSIONS This surgical strategy was effective for arch aneurysm and produced less damage than a conventional procedure to the postoperative respiratory function, while the operative technique need to be improved to decrease the frequency of brain and spinal cord injury.

Endovascular Treatment of Aortoduodenal Syndrome.

PURPOSE Duodenal obstruction caused by aneurysmal dilatation of the abdominal aorta is a rare clinical entity that is traditionally treated by open aneurysm repair, aneurysmorrhaphy, and duodenal release. We present here the case of aortoduodenal syndrome treated by endovascular therapy. CASE REPORT A 73-year-old man diagnosed simultaneously with sigmoidovesical fistula and an abdominal aortic aneurysm (AAA) underwent resection of the sigmoid colon followed by colostomy. On postoperative day 34, the patient experienced nausea and vomiting. Computed tomography revealed the AAA causing duodenal obstruction by direct compression. We chose endovascular therapy for treating the AAA rather than graft replacement because of the risk of infection by the colostomy orifice. Postoperatively, the patient reacquired the ability to eat. However, postoperative computed tomography revealed that the diameter of the AAA had not changed. CONCLUSIONS We considered that the decreased intra-aneurysmal pressure caused a release of duodenal obstruction.

Surgical repair of unroofed coronary sinus atrial septal defect in an adult

Physical examination a 73-year-old woman with dyspnea revealed a systolic murmur at the 2nd intercostal space along the left sternal border. Chest radiography revealed right heart enlargement. Electrocardiography indicated normal sinus rhythm. Transesophageal echocardiography showed a dilated coronary sinus located at both atria. The pulmonary-to-systemic blood flow ratio was 2.46. Chest computed tomography revealed an unroofed coronary sinus atrial septal defect (Figures 1 and 2). She was diagnosed with unroofed coronary sinus atrial septal defect without persistent left superior vena cava. At surgery, an ostium opening into the right atrium was found (Figure 3). We performed autologous pericardial patch closure of the ostium, leaving the coronary vein draining into the left atrium. The patient was discharged 11 days postoperatively in a satisfactory condition without any critical complications.