[Thickness of the muscle layer of the gastroepiploic artery and the internal mammary artery--a presumable factor of flow instability in GEA during the perioperative period]

Recently the right gastroepiploic artery (RGEA) is often used for coronary bypass grafting. Although patency rate of the RGEA is as high as that of the IMA, instability of blood flow through the RGEA during the perioperative period is reported. We assumed that the RGEA is more predisposed to spasm than the internal mammary artery (IMA). This study was carried out to verify the following two points. 1. The GEA has a smaller internal diameter and thicker muscle layer than the IMA. 2. The contractile force of the muscle layer of the GEA are stronger than those of the IMA under the same transmural pressure due to the greater thickness o the muscle layer of the GEA.

METHODS

The RGEA was obtained at its full length from gastorectomy cases due to gastric cancer (n = 25). The distal section of the IMA was obtained from the left IMA during bypass grafting (n = 23). All specimens were stained by the Masson-trichrome method and examined microscopically. The thickness of the smooth muscle layer of the media and the internal radius were compared between the RGEA and the IMA.

RESULTS

The thickness of the muscle layer was 274.0 +/- 13 microns in the RGEA, and 169.1 +/- 8 microns in the IMA (p < 0.01) that is the thickness in the GEA was 1.62 times greater in the IMA. Although a significant difference was not obtained, the internal radius of GEA (563.7 +/- 21.8 microns) was smaller than that of IMA (583.1 +/- 12.0 microns). Based on the internal diameter-elastic wall tension relationship and the Laplace law, internal diameter and elastic tension in both arteries were obtained at the same blood pressure. Mean elastic tension and internal diameter in the GEA were considered to be smaller than than those in the IMA. The values of the internal diameter of the arteries obtained from the theoretical view point were correlated well with those obtained by the histometoric methods. As the muscle layer of the arterial wall of the GEA is thicker than that o the IMA, and the internal diameter of the GEA tends to be smaller than that of the IMA, the stronger contraction o the muscle layer, when induced, would reduce the blood flow in much greater extent in the GEA than the IMA.

CONCLUSION

These results support the assumption that the RGEA reacts strongly than the IMA to constructor agents and physical stimuli, thereby inducing a greater instability of blood flow. Therefore, RGEA grafts should be carefully handled during bypass grafting.

[A case of effusive-constrictive pericarditis and its surgical treatment]

A 69-year-old male of effusive-constrictive pericarditis with a symptom of right heart failure was reported. The patient underwent surgery, as the medical treatment had not been effective. Through median spritting, very thickened pericardium and calcified epicardium of the right atrium, the right ventricle and the left ventricle were resected as largely as possible. In the space between the pericardium and epicardium, there existed yellow and thick fluid of about 50 ml which was evacuated. After surgery hemodynamic improvement was observed and the patient experienced a smooth postoperative course. Although pathological examinations revealed no special findings except the increased activity of adenosine deaminase of the yellow and thick fluid, tuberculosis was mostly suspected as the cause of the disease.

[Penetrating atherosclerotic ulcer of the iliac artery combined with abdominal aortic aneurysm--a case report]

A 76-year-old woman with abdominal aortic aneurysm was referred to our hospital with a complaint of abdominal pulsatile mass. CT and angiogram revealed infrarenal abdominal aortic aneurysm (AAA) with right common iliac aneurysm. AAA was replaced with the bifurcated Dacron graft and iliac aneurysm was resected concomitantly. A focal perforation of intima and medial wall hematoma were found in the iliac aneurysm. These findings corresponded with penetrating atherosclerotic ulcer (PAU). PAU in the abdominal aorta may form the abdominal aortic false aneurysm, and may cause the rupture of aneurysm. It is an critical sign of "aortic catastrophe".

[Mitral valve replacement secondary to resection of mycotic cerebral aneurysm in acute phase of bacterial endocarditis--a case report]

We report a case of mitral valve replacement after ruptured mycotic aneurysm resection in acute phase of bacterial endocarditis. We have experienced a 68-year-old man with vegetation at the anterior leaflet of mitral valve and multiple systemic embolization. He underwent aneurysmectomy of ruptured mycotic cerebral aneurysm and embolectomy of left femoral artery eight days after subarachnoid hemorrhage. Mitral valve was replaced three days after successfully. If there was no heart failure preoperatively, valve replacement operation is recommended in acute phase of infected endocarditis or few days after cerebral aneurysmectomy.

[Two cases of coronary artery bypass grafting using great saphenous vein grafts in reversed Y-shaped for the atherosclerotic ascending aorta]

Coronary artery bypass grafting (CABG) was performed using saphenous vein grafts anastomosed in reversed Y-shaped in two patients because of the atherosclerotic ascending aorta. Postoperative course was uneventful, however, the common part of reversed Y-shaped grafts was occluded in both patients within two years after operations. The arms of reversed Y-shaped grafts were patent, and played a role of major collateral between LAD and RCA. They were treated successfully with reoperation in one patient and PTCA in another.

[A case of Cabrol's procedure in which selective cerebral perfusion was necessitated]

A 69-year-old man underwent Cabrol's procedure for annuloaortic ectasia and complicated multiple cerebral infarction. Preoperative CT scan showed atherosclerotic changes from the aortic arch to descending aorta. During extracorporeal circulation, arterial cannulation was made through left subclavian artery to prevent cerebral infarction due to detouched atheroma from the descending aorta. Intraoperatively, the ascending aorta was also atheromatous and ulcerative. In this case, cerebral infarction was most likely due to detouched atheroma from the aortic arch in retrograde blood flow during extracorporeal circulation. To prevent this complication, selective cerebral perfusion during extracorporeal circulation should have been selected.

[Simultaneous operations for ischemic heart disease and lung cancer]

Two cases were operated on simultaneously for coronary revascularization and lung resections for cancer. Case 1 was a 79 year-old man, diagnosed with two vessels coronary artery disease and squamous cell carcinoma of left lower lobe. At the end of aortocoronary bypass grafting to LAD and first diagonal branch using saphenous vein, median sternotomy was closed, and lower lobectomy was performed through left posterolateral standard thoracotomy. Case 2 was a 65 year-old man who underwent aortocoronary bypass grafting to LAD first and left lingular segmentectomy via median sternotomy simultaneously. We concluded that a simultaneous operation was definitively and ideally a preferable method in most selected cases. The order of two operations for coronary artery and lung was also discussed.

[Mitral valve re-replacement for a patient with multiple myeloma]

Mitral valve re-replacement was successfully undertaken in a 70-year-old female patient with primary tissue failure of mitral bioprosthesis and multiple myeloma (MM) through right lateral thoracotomy with minimum dissection. Considering the post-operative anti-coagulant therapy, bioprosthesis was chosen in this complicated case. Patients with MM usually show a bleeding tendency associated with abnormally elevated IgG which covers the surface of coagulation factors. Safety range of serum IgG concentration in the patients with MM who require open heart surgery, have not defined yet. Excessive serum IgG leads the coagulation disorder and organ perfusion problem because of increase of blood viscosity. Those problems become serious when the serum IgG concentration exceed 2,500 mg/dl. (1) Only if serum IgG level below 2,5000 mg/dl, valve replacement will be able to perform safely with minimum dissection through the thoracotomy for patients with MM. (2) Bioprosthesis might be optionally chosen in such case (3). In case of serum IgG level over 2,500 mg/dl, preoperative plasma ex-change should be recommended.

[A case report of surgically treated tracheobrachiocephalic artery fistula following tracheostomy]

The patient was a 17 year-old-boy with mental retardation and cerebral palsy, who underwent tracheostomy because of tracheobronchomalacia and tongue swallowing three months ago. After minimal tracheostomy bleeding was noted for a few days, massive hemorrhage occurred suddenly. The patient was severely hypotensive. The cuff on the tracheostomy tube was hyperinflated, which stopped the bleeding temporarily. Through a median sternotomy and collar incision, a pin hole-sized defect in the medial surface of the brachiocephalic artery at the tracheal balloon was repaired by suture. The tracheal defect allowed visualization of the tracheal cannula balloon. The pectoralis major muscle flap was interposed between the tracheal defect and the artery. The tracheal defect was packed with muscle. Seven days after the operation, the second operation was done for recurrent bleeding. The defective segment of brachiocephalic artery was resected and the ends were oversewn with monofilament sutures. Continuous irrigation with povidone-iodine solution was continued for purulent mediastinitis. We believe that interruption of blood flow of the brachiocephalic artery, interposition and packing of muscle flap over the tracheal defect and continuous irrigation for infection were effective treatment of choice.

[Aortic root reconstruction in the patient with aortic root dissection and aortic valve regurgitation: a case report]

The reported patient was a 60-year-old man with congestive heart failure and recurrent inferior myocardial infarction. The aortogram revealed severe aortic regurgitation, aortic root dilatation and dissection with involvement of the right coronary ostium. Aortic root reconstruction using the valved conduit was performed. The left coronary ostium was reimplanted with Carrel patch method and the right coronary artery was bypassed with the saphenous vein graft. Postoperative course was uneventful and he is asymptomatic in one year after operation. Although aortic root reconstruction with Carrel patch procedure is not widely adopted in Japan, we recommend this procedure because the anastomosis between the coronary ostium and the graft is tight.

[A sharp edge of the fractured ribs caused the aortic injury at body-position change: a case report]

The reported patient was a 37-year-old male, who got a blunt chest trauma by a motor vehicle accident. Chest X-ray and computed tomography of the chest revealed bilateral multiple rib-fractures, pneumo-hemothorax, lung contusions, but no evidence of mediastinal hematoma. Since respiratory distress with a flail chest was observed, the patient was placed on an artificial ventilation, and thoracocentesis were also done on both sides, while the hemodynamics was fairly maintained with blood transfusion. On the 10th hospital day, however, he suddenly fell into a deep shock with the left hemothorax by changing the body position. Emergency thoracotomy demonstrated the laceration of the descending aorta, that was considered to be made by the sharp edge of the fractured left 8th rib, which correspondingly protruded into the thoracic cavity toward the aorta. The repair of the aortic injury and the resection of the rib edges were performed. He was discharged on the 45th hospital day. In cases with a blunt chest trauma, the majority of the causes of the traumatic aortic injury are reported to be "deceleration injury". Although the considered mechanism of the traumatic rupture of the thoracic aorta in this case is extremely rare, it should be taken into a consideration for treatment of the cases with a blunt chest trauma and multiple rib-fractures.

[Surgical results of two cases of simultaneous surgery of carotid and coronary occlusive disease]

Two cases of symptomatic extracranial carotid artery stenosis associated with ischemic heart disease are reported. The first case was 72-year-old male, who was admitted because of transient ischemic attack due to the stenosis of left internal carotid artery. He had a history of myocardial infarction and coronary angiography revealed three vessel disease. The second case was 74-year-old female with diabetes mellitus. She was admitted because of cerebral infarction. The carotid angiography revealed critical stenosis of bilateral internal carotid arteries. Her coronary angiography revealed three vessel disease. Her chest symptom became unstable after her admission. In both cases, simultaneous carotid endarterectomy and coronary bypass grafting were performed with successful outcome. In the patients with symptomatic extracranial carotid occlusive disease associated with severe ischemic heart diseases, we advocate simultaneous operation both for carotid and coronary artery occlusive disease.