Toshimi Yajima

Aortic dissection extending from the left coronary artery during percutaneous coronary angioplasty

A 72-year-old woman with acute aortic dissection as a complication of percutaneous coronary angioplasty was successfully treated. She received a graft replacement of the ascending aorta as well as triple coronary artery bypass grafts. The dissection had extended from the left coronary artery. Although acute aortic dissection is a rare complication of percutaneous coronary angioplasty, physicians and cardiac surgeons should keep its potential occurrence in mind.

Simultaneous subclavian artery reconstruction in coronary artery bypass grafting

BACKGROUND Subclavian artery occlusive lesion, although rare, is sufficiently important to consider before coronary artery bypass grafting because it can cause not only symptoms of the lesion per se, but also the postoperative coronary-subclavian steal phenomenon. METHODS Four patients undergoing coronary artery bypass grafting received simultaneous reconstruction of the subclavian artery. During aortic cross-clamping, an 8-mm ring-reinforced polytetrafluoroethylene graft was attached to the aorta perpendicularly. The prosthetic graft was led to the proximal segment of the axillary artery through the second intercostal space and anastomosed to the inferior surface of the artery. RESULTS Three patients received unilateral reconstruction of the subclavian artery, whereas another received bilateral reconstruction. There were no complications related to the subclavian reconstruction procedure. Post-operative angiograms revealed excellent patency of the prosthetic grafts. All of the patients have been asymptomatic with follow-up periods ranging from 9 to 50 months. CONCLUSIONS To perform simultaneous subclavian artery reconstruction along with coronary artery bypass grafting, the aortoaxillary bypass procedure using an 8-mm polytetrafluoroethylene graft may be the method of choice because it has lower potential for complications and is less technically demanding.

Protection effects of a silver fiber textile against electromagnetic interference in patients with pacemakers

Abstract The use of the wireless cellular phone has increased dramatically, and this use could influence pacemaker function with electromagnetic interference (EMI). A textile lined with silver fiber has been developed for protection against electromagnetic waves. The purpose of this study was to evaluate the EMI protection effects in cardiac pacemaker patients wearing this textile. Participants in this study had pacemakers that were capable of obtaining endocardial electrograms, markers/annotations, and surface electrocardiograms via a programmer. A cellular phone was placed over the pulse generator. The presence of EMI was confirmed when a change in a parameter was observed. When EMI was confirmed, the subject wore a silver fiber shirt (rated at −30 dB), and EMI was evaluated. If the EMI persisted, the subject wore a heavier silver fiber shirt (rated at −50 dB), and again EMI was assessed. The same procedure was performed by using a ham radio device. Thirty-one subjects were tested. There was no EMI observed with the use of a cellular phone. However, interference by a ham device was confirmed in eight subjects (25.8%). Among six subjects, no further interference was observed after the patient wore a −30 dB shirt. For one subject, EMI was eliminated when a −50 dB shirt was used. However, one subject demonstrated persistent EMI when wearing a double layer of −30 dB and −50 dB shirts. Beneficial protection from EMI with the use of clothing lined with silver fiber has been demonstrated in this study. However, electromagnetic waves are diverse in both source and strength. Future studies are needed to confirm the benefits of wearing silver fiber clothing for the reduction of pacemaker–EMI interaction.

Continuous transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass in children

The purpose of this study was to evaluate the effectiveness of transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass after intracardiac repair in children. The left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion were monitored continuously by transoesophageal echocardiography in controls weaned easily from cardiopulmonary bypass (group A, n = 25), and those weaned with difficulty from cardiopulmonary bypass after mechanically assisted circulation (group B, n = 16). In group A, left ventricular ejection fraction and left ventricle wall motion were within normal range, and did not change significantly during weaning after cardiopulmonary bypass when compared with pre-bypass data. In contrast, left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion in group B during the first trial of weaning from bypass were significantly worsened. Hence, assisted circulation was performed until the data obtained via transoesophageal echocardiography improved with regard to maintenance of fluid balance, catecholamine dosage and assisted pump flow. All cases in group B were weaned safely from cardiopulmonary bypass despite their critical condition. In conclusion, continuous transoesophageal echocardiography monitoring may be a useful tool in children with severe heart failure for safe weaning from cardiopulmonary bypass after intracardiac repair.

Impact of sequential grafting of the internal thoracic or right gastroepiploic arteries on multiple coronary revascularization.

OBJECTIVE The aim of the study is to clarify the efficacy of the sequential anastomotic technique of the arterial conduits for multiple coronary revascularization. BACKGROUND The internal thoracic artery (ITA) is now widely accepted as a durable conduit for myocardial revascularization. The right gastroepiploic artery (GEA) has been developed as a third in situ arterial graft with an outcome similar to that of the ITA. MATERIAL AND METHOD One hundred and forty five consecutive patients (116 male, 29 female, mean age 60.4yr) who received sequential grafting of either the ITA or GEA or both were retrospectively analysed. RESULTS Sequential anastomoses were performed in 121 in situ left ITAs, 36 in situ GEAs and 12 composite right ITAs. No in situ right ITA was anastomosed sequentially. Two to six vessels (mean 3.8) were revascularized for each patient. Of the total 543 bypassed vessels, 432 (79.6%) were reconstructed with the arterial grafts. In 85 patients with quadruple bypass or more, the arterial grafts were able to reconstruct 266 out of 360 (74.0%) target vessels. Seventy one patients (49.0%) were revascularized without venous grafts. The arterial grafts could revascularize 293 out of 310 vessels (94.5%) in the LAD approximately Diagonal region, 83 out of 113 (73.4%) in the distal RCA or Cx region. There were no cardiac events responsible for the arterial grafts in the follow up period. CONCLUSION In light of our experience, multiple revascularization with in situ arterial sequential grafts is feasible. Aggressive application of this technique provides patients requiring multiple coronary revascularization with favorable long-term results.

The Clinical Significance of Performing Preoperative Angiography of the Internal Thoracic Artery in Coronary Artery Bypass Surgery

This study was designed to clarify the clinical significance of and indications for performing preoperative internal thoracic artery (ITA) angiography in patients undergoing coronary artery bypass surgery. A total of 300 possible candidates for coronary artery bypass grafting (CABG) underwent ITA angiography during diagnostic catheterization. Semi-selective angiography of bilateral ITAs were performed by injecting contrast medium manually with a 5-F right Judkins coronary catheter. The posteroanterior view of the arteriograms was recorded on a 35-mm cine film or a cut-film. Unusual angiographic findings of the ITAs were observed in nine patients (3%). These findings included: an atrophic ITA in three patients with ipsilateral subclavian artery occlusions; enlarged ITAs giving collaterals to the lower extremities in one patient with extensive aortoiliac occlusive disease; occluded ITAs in one patient with Takayasus arteritis and two patients with a history of CABG; and a small but nonsclerotic ITA in one patient. Atherosclerotic occlusive ITAs were found in only one patient. Thus, we concluded that routine preoperative angiography of the ITA is not necessary because it is rarely affected by atherosclerosis. However, it should be performed for any of the following reasons: a cervical or supraclavicular bruit; an upper extremity blood pressure difference of greater than 20 mmHg; an extensive aortoiliac occlusion; and certain disorders such as Takayasus arteritis or Kawasaki disease, or a history of open heart surgery.

Effects of muscle potential depression and muscle stimulation caused by different insulation coating configurations on cardiac pacemakers

Insulation coating was added to the external pacemaker surface to prevent unnecessary electric current leakage to the periphery because the pulse generator body is used as an anode in unipolar pacing. However, a model without insulation coating has recently been used, so we studied the effects on muscle potential inhibition and muscle stimulation of pacemakers in unipolar pacing with different parts of the pacemaker body coated with insulation. Case comparisons were made for the following models: insulated except for the center of one side (33, group C), insulated except for the peripheral zone (10, group E), and noncoated models (11, group N). The muscle detection threshold voltage, muscle detection threshold pulse duration, muscle potential sensing threshold (MP), and lead resistance were measured. A comparison was made of the amount of energy (En) needed to reach the muscle stimulation threshold. For MP values, there was no significant statistical difference between group C and E, whereas a significant difference was present between group C and N and between group E and N. For En values, there was a significant difference between group C and E and between group C and N, but there was no significant difference between group E and N. The muscle potential sensing threshold dose not have a change in group E and much muscle stimulation energy is needed. The muscle potential sensing threshold was low in group N, requiring much muscle stimulation energy. Based on these results, it is usually not necessary to coat the pacemaker with insulation for unipolar pacing.

“Hexatuple” coronary bypass with in situ arterial grafts

A fifty-seven year old male patient with severe three-vessel coronary artery disease underwent successful coronary bypass surgery in six vessels utilizing the in situ left internal thoracic and right gastroepiploic arteries. Each arterial conduit was anastomosed sequentially to as many as three coronary vessels respectively. Surgical results were excellent and the patient continues to do very well. A postoperative angiogram showed well-working arterial conduits without any anastomotic problems. Multiple sequential anastomoses of the in situ arterial conduits, although rather technically demanding, can provide better long-term results in patients requiring multiple coronary revascularization. When sequential anastomoses of the right gastroepiploic artery are being considered, the length and caliber of the artery should be evaluated by an angiogram since it varies in size compared to the internal thoracic artery.

Aortic dissection with pseudo-aortic regurgitation and transient myocardial ischemia--a case report.

Aortic dissection causes acute aortic regurgitation in one half to two thirds of cases, which is due, mainly, to dilatation of the aortic root. The unsupported intimal flap prolapse, which crosses the aortic valve, rarely produces aortic regurgitation. Moreover, transient myocardial ischemia rarely occurs by malperfusion, which might be due to compression of the ostium of the coronary artery by the false lumen or by the intimal flap. The authors had a rare case of aortic dissection with “pseudo-”aortic regurgitation; ie, regurgitation flow existed just in the area surrounding the intimal flap during diastole and produced transient myocardial ischemia. In this case, the swinging motion of the intimal flap through the aortic valve caused pseudoaortic regurgitation and transient myocardial ischemia, which should be repaired by emergency surgical procedure. Surgery was successful and saved the patient’s life.