Kouichi Hisatomi

Intramural hematoma of the thoracic aorta

OBJECTIVE This study was designed to clarify the optimal treatment mode of patients with intramural hematoma (IMH) of the thoracic aorta. METHODS From 1992 through 1997, 51 patients underwent surgical repair or medical treatment of IMH of the thoracic aorta. There were 36 male and 15 female patients, aged between 49 and 79 years with a mean of 67 years. The ascending aorta and/or aortic arch was involved in 18 patients (group I), whereas the descending thoracic aorta was affected in 33 (group II). The presence of intimal disruption in IMH was confirmed in 10 of group I and 13 of group II patients. RESULTS For group I patients 13 required aortic arch repairs and the remaining 5 underwent conservative therapy including anti-hypertensive medication. Primary indications for immediate surgery were: cardiac tamponade in 5 patients, aortic dissection superimposed on IMH in 2, and persistent pain with an aortic arch aneurysm in 1, respectively. Early elective operations were done for enlarged ulcer in 3 patients and aneurysmal dilatation in 2 of which 1 had a coexisting aortic arch aneurysm. The 2-year survival rate after diagnosis was 94% with an operation-free rate of 25%. Nine of the group II patients experienced surgical intervention of which 8 had intimal disruption, 4 patients received urgent replacement of the descending thoracic aorta for massive pleural effusion and 1 had the aortic arch replaced for a coexisting aneurysm with persistent pain. All other patients underwent conservative treatment and 4 of them had to be shifted to early surgery during the initial hospitalization because of an enlarged ulcer. The 5-year survival rate in group II patients was 63% with an operation-free survival rate of 66%. CONCLUSIONS On the basis of our experience early operation is recommended for almost all patients with ascending aortic IMH, and medical therapy for those with descending aortic involvement unless complication developed. However, the presence of intimal disruption may require early surgical treatment even in the patients with descending thoracic IMH.

Mitral valve repair for mitral regurgitation with ventricular septal defect in children.

BACKGROUND We examined the results of intermediate and long-term follow-up of 25 patients aged 3 months to 11 years (mean, 2.6 +/- 2.3 years) who initially underwent conservative mitral valve repair for mitral regurgitation associated with ventricular septal defect between April 1973 and March 1991. METHODS The preoperative degree of mitral regurgitation was 2+ in 3, 3+ in 17, and 4+ in 5 patients, and the major causes of mitral regurgitation were annular dilatation and prolapse of the anterior leaflet. Annuloplasty was performed in all except 2 patients, suturing of the cleft was done in 3 patients, and posterior mitral leaflet advancement was done in 2 patients. In addition, the papillary muscle was incised and adhesive chordae were removed in 1 patient, and adhesive fused chordae were detached from a leaflet in 1 other patient. RESULTS There were no early deaths. Two patients with residual mitral regurgitation with or without mitral stenosis underwent reoperation for mitral valve replacement 2 months and 6 years after the mitral repair, respectively. Late death occurred in 2 patients, and the actuarial survival rate was 92.0% at 15 years after operation. The freedom from reoperation was 91.3% at both 10 and 15 years after the initial operation. Postoperative color Doppler flow imaging was performed in 22 of the 23 survivors, and results showed no mitral regurgitation in 4, mild regurgitation in 14, and moderate regurgitation in 4 patients. Four patients presently have mitral stenosis, with a mean transmitral pressure gradient greater than 10 mm Hg. The residual lesion of moderate mitral regurgitation with or without mitral stenosis developed in 6 of 11 patients in whom bilateral mitral annuloplasty was applied after the initial operation. Nineteen of the 22 survivors without reoperation were in New York Heart Association class I, and 3 were in class II. CONCLUSIONS Clinical improvement was observed after conservative mitral repair in most pediatric patients with ventricular septal defect. However, careful follow-up for growth potential still appears to be needed to detect changes in mitral regurgitation and the development of mitral stenosis after valve repair, especially after bilateral annuloplasty.

Penetrating atherosclerotic ulcers in an abdominal aortic aneurysm: Report of a case

We report the case of a 74-year-old man found to have an extensive intramural hematoma (IMH) in the infrarenal abdominal aorta during a follow-up imaging study performed after repair of a DeBakey type II aortic dissection with an aortic arch true aneurysm. Enhanced computed tomographic scan and angiography revealed an extensive IMH and multiple penetrating atherosclerotic ulcers in the abdominal aorta. The patient underwent a successful replacement of the affected abdominal aorta using a collagen-impregnated woven Dacron graft. Atheromatous ulcers are known to occur frequently in patients with advanced atherosclerosis. Hence, the elderly hypertensive patient, being at high risk of developing a variety of aortic disorders, requires careful follow-up imaging studies to assess the aorta on a regular basis.

The St. Jude medical prosthesis in the mitral position.

To study the long-term results of the St. Jude medical prosthesis in the mitral position, 520 patients were evaluated who had undergone mitral valve replacement with St. Jude medical (SJM) prosthesis. Eighteen patients or 3.5% died in the early postoperative period (within 30 days after operation). The total follow-up was 2872 patient-years and late deaths occurred in 23 cases. Postoperative cerebral embolism occurred in six, bleeding complication in five, and thrombosed valve in two patients. Postoperative anti-coagulant therapy was initiated with both dipyridamole (300 mg/day) and warfarin potassium. After discharge from our hospital the patients underwent routine examination of their thrombo-tests or prothrombin times at least every 2-3 months, and the major thromboembolic or bleeding complication rate was 0.45%/100 patient-years. In a period of 12 years, severe hemolysis following implantation was seen in seven patients. The cause of this hemolysis was perivalvular leakage in two patients but there were no leakages in the other five patients, although preoperative moderate to severe liver dysfunction was noted. Ninety-three percent of the patients were followed up, and their postoperative New York Heart Association functional classes were I or II in 88.6% of the cases. Their clinical results after mitral valve replacement with SJM prosthesis in the anti-anatomical position showed excellent durability and a low incidence of valve-related complications.

Is direct closure dangerous for treatment of doubly committed subarterial ventricular septal defect

BACKGROUND We performed direct closure of doubly committed subarterial ventricular septal defects with aortic cusp prolapse. Postoperative echocardiographic studies showed that this method improved coaptation of the prolapsing aortic cusp, especially in patients with mild aortic regurgitation (AR). METHODS Twenty-one patients (mean age, 7.8+/-4.3 years; range, 2 to 18 years) with doubly committed subarterial ventricular septal defect underwent direct closure alone. Aortic valve prolapse was observed in all 21 patients, with mild AR found in 13 patients but not in the remaining 8. The site of the prolapsed aortic valve was in the right coronary cusp in all patients. We inserted an interrupted 4-0 or 5-0 polypropylene suture with a pledget from the lower margin of the ventricular septal defect to the pulmonary ring to increase protrusion of the prolapsed cusp by pushing it back and to improve coaptation of the aortic cusp. RESULTS The interval between surgical treatment and the last postoperative evaluation ranged from 3 to 24 months (median, 11 months). No residual ventricular septal defect was detected in any patient. In the 8 patients who had aortic valve prolapse without AR preoperatively, no AR was found at follow-up. Of the 13 patients who had mild AR associated with aortic valve prolapse preoperatively, AR diminished in 7 and did not progress in the remaining 6. Furthermore, no anatomic changes in either the aortic or pulmonary annulus were found on follow-up echocardiography. In the group of 13 patients with mild preoperative AR, AR significantly persisted in patients who were more than 10 years old at operation (p<0.05). CONCLUSIONS Our findings suggest that direct closure for this type of ventricular septal defect is safe and reliable in improving mild AR and that direct closure is more effective for younger patients in whom the prolapsing aortic cusp is mobile enough to be protruded. However, further long-term follow-up studies will be needed to ascertain the adequacy and usefulness of the method.

Coronary Artery Aneurysm Repaired With Saphenous Vein Patch Plasty

The presence of atherosclerotic coronary artery aneurysms is not always considered to be an operative indication. However, progressively expanded coronary artery aneurysms may have the potential for complications such as rupture or embolism. We present a case of successful repair of a coronary artery aneurysm located above the first septal perforator in the left anterior descending coronary artery using a saphenous vein patch and simultaneous construction of a right gastroepiploic artery graft to the occluded right coronary artery. Follow-up angiography at 6 months after operation revealed complete disappearance of the aneurysm with no luminal stenosis and a preserved large septal branch. The right gastroepiploic artery graft was also found to be widely patent.

Coronary artery aneurysm after stent implantation

A coronary artery aneurysm that developed 6 months after coronary stent implantation in the left anterior descending artery, was treated by double coronary artery bypass grafting due to restenosis of the affected vessel and progression of right coronary artery stenosis. Although the poststenting aneurysm initially remained postoperative angiography showed that it had disappeared. In addition to thrombotic occlusion, another mechanism behind its disappearance may be that geometric changes of the implanted stent caused by heart retraction during surgery closed the entrance to the aneurysm.

Effect of the Addition of Albumin to Crystalloid Cardioplegic Solutions on Myocardial Metabolism in Infants Undergoing Open Heart Surgery

The effect of the addition of albumin to crystalloid cardioplegic solutions was investigated in infants who underwent open heart surgery. The patients were divided into four groups according to whether or not they received a composition of crystalloid cardioplegic solutions containing albumin. Cardioplegic solution (Kurume solution) without albumin was administered to 12 patients (group 1); Kurume solution with 1% albumin to 10 patients (group 2); GIK solution without albumin to 10 patients (group 3); and GIK solution with 1% albumin to 15 patients (group 4). All patients had a ventricular septal defect and underwent closure of the defect with Dacron double velours through either the tricuspid or pulmonary valve. Our results showed that the percent oxygen extraction in group 2 was significantly greater than that in group 1, while the value in group 4 was less than that in group 3 at 5 min after reperfusion. No significant differences were seen between groups 1 and 2, or between groups 3 and 4, regarding the value for creatine kinase muscle-brain (MB) for any measurements during reperfusion. However, regarding the percent lactate and the malondialdehyde extraction values, significant differences between the groups with and without albumin were noted 5 min after reperfusion. These results did not completely support the addition of albumin to crystalloid cardioplegic solutions to help preserve myocardial aerobic metabolism in infants; however, such an addition might contribute to the preservation of myocardial lactate utilization while also helping to inhibit lipoperoxide metabolism immediately after reperfusion.

Application of a manifold system for temporary reperfusion during proximal anastomoses in conventional coronary bypass surgery.

We report the application of a manifold system which is attached to saphenous vein grafts after the completion of distal coronary anastomosis. This technique permits not only the direct delivery of cardioplegic solution into the distal coronary artery, but also the reperfusion of revascularized coronary arteries via saphenous vein grafts by changing the connection to the arterial circuit during proximal anastomosis under a partial occlusion of the aorta in conventional coronary artery bypass surgery.