Growth potential of left internal thoracic artery grafts: analysis of angiographic findings

BACKGROUND

The growth potential of the internal thoracic artery (ITA) is still undetermined, and little is known about the long-term effects of anastomosing it to the coronary artery.

METHODS

Fifty-three patients whose left ITA (LITA) had been anastomosed to the left anterior descending (LAD) coronary artery underwent coronary angiography within 1 month of operation and in late follow-up (mean interval: 4.5 +/- 1.5 years). The diameter ratios of LITA to LAD were designated as the matching ratio.

RESULTS

In follow-up, the diameter of the LITA increased from 1.83 +/- 0.40 to 2.46 +/- 0.53 mm in the 29 patients with progressive proximal native coronary stenosis. However, late results indicate that the matching ratio did not vary according to the location of the LITA anastomosis on the LAD (proximal portion: 1.13 +/- 0.16, distal portion 1.19 +/- 0.13), and reached an upper limit of about 1.4.

CONCLUSIONS

Growth potential of the LITA is limited by the diameter of the coronary artery onto which it is anastomosed. The most effective procedure for enhancing the growth potential of the LITA is to anastomose as proximally as possible onto the LAD.

[Surgical treatment for malignant pleural mesothelioma in eight cases]

Between 1987 and March 2000, we have operated on eight patients for malignant mesothelioma which consisted of four of localized type and four of diffuse type. We have aggressively resected mesothelioma combined with chemotherapy whether the tumor was primary or recurrent, and concluded the following. 1) In localized malignant mesothelioma, en-bloc primary tumor resection was possible and additional resection for recurrence was effective and useful for long time survival. 2) In diffuse malignant mesothelioma, complete tumor resection was impossible to even perform pleuropneumonectomy accompanied with partial resection of pericardium and diaphragm and, therefore, the prognosis was poor in four patients and all died around one year. 3) Because recurrent pattern for localized type was diffuse type, diagnosis and surgical treatment in early stage was essential for long time survival.

Long-term results of bilateral internal thoracic artery grafting

BACKGROUND

Little is known about the long-term results of the uniform group of patients who had bilateral internal thoracic artery (ITA) grafting with the method of left ITA-to-left anterior descending coronary artery and right ITA-to-circumflex artery.

METHODS

Late follow-up study was performed in the first consecutive 203 patients (mean age, 62.6 +/- 9.1 years) who underwent isolated coronary artery bypass grafting with the left ITA anastomosed to the left anterior descending coronary artery and the right ITA to major branches of the circumflex artery. The patients were grouped according to the patency of ITA grafts demonstrated by early postoperative angiography (Both patent (BP) group, 168 patients: both ITAs showed complete patency; Not patent (NP) group, 23 patients: at least one ITA was dysfunctional).

RESULTS

Actuarial 7-year survival in all patients was 89.3% +/- 3.1%. The cumulative probability of event-free survival for cardiac death, myocardial infarction, intervention, and angina at 7 years was 96.6% +/- 1.8%, 98.0% +/- 1.5%, 86.7% +/- 3.2%, and 90.7% +/- 2.9%, respectively. NP group had more myocardial infarction and angina than the BP group, but was not statistically significant. Because of failed grafts at the early angiography, intervention was performed more frequently in NP group (p < 0.01).

CONCLUSIONS

Our results of actuarial 7-year survival and the cumulative probability of event-free survival were at least comparable to the results of other similar studies using bilateral ITA. The freedom from angina appeared to be better than in the previous study. Overall our study supports the continued use of this method of ITA grafting.

Complete revascularization of the left anterior descending coronary artery

OBJECTIVE

To assess the efficacy of complete revascularization of the left anterior descending coronary artery.

METHODS

To obtain such revascularization, 81 patients required the use of such complex techniques as the onlay patch technique or double bypasses during bypass grafting.

RESULTS

The onlay patch technique was used in 39 (48%) and double bypasses in 42 (52%). The wall motion in all anterior segments of the left ventricle showed an improving trend postoperatively. The patency rate was 99% overall, and the bypass grafts to the left anterior descending coronary artery were all patent with flow in all left anterior descending coronary artery areas. Perioperative myocardial infarction occurred in only 1 patient (1.2%), and hospital mortality was 2.5% (2/81). Long-term results of 79 hospital survivors were as follows: the mean follow-up time was 77 months (3 to 236); the actuarial survival rate including all deaths and estimated by cardiac death was 90% and 95% at the eighth postoperative year respectively; the cardiac event free rate at the fifth and eighth postoperative year was 90% and 63% respectively. A total of 8 cardiac events were observed. Excluding 3 cardiac deaths, no cardiac events were clearly attributable to the left anterior descending coronary artery.

CONCLUSIONS

Complete revascularization of the left anterior descending coronary artery using these techniques improved the anterior wall motion in the left ventricle and cardiac performance at low risk, and provided excellent long-term results.

Inhibition of transforming growth factor beta prevents progression of liver fibrosis and enhances hepatocyte regeneration in dimethylnitrosamine-treated rats

We investigated whether anti-transforming growth factor beta (TGF-beta) molecular intervention can halt the progression of liver fibrosis in rats. To block TGF-beta action in a specific manner, we prepared an adenovirus expressing a truncated type II TGF-beta receptor (AdTbeta-TR), which specifically inhibits TGF-beta signaling as a dominant-negative receptor. We also used an adenovirus expressing bacterial beta-galactosidase (AdLacZ) as a control adenovirus. Rats were treated with dimethylnitrosamine (DMN) for 3 weeks; then, AdTbeta-TR, AdLacZ, or saline was intravenously applied once, followed by an additional 3-week DMN treatment. The ratio between the truncated receptor and the wild-type receptor at the mRNA level was 15 at 1 week and 10 at 3 weeks after gene transfer. Immunohistostaining analysis showed that the truncated receptor was expressed mainly in septal cells including hepatic stellate cells. Liver fibrosis, as assessed by histology, hydroxyproline content, and the serum level of hyaluronic acid, progressed during the additional 3-week DMN treatment. However, in rats infected with AdTbeta-TR, the fibrosis remained at the level seen in rats given DMN for only 3 weeks. All AdTbeta-TR-treated rats remained alive, whereas DMN-treated rats infused with either AdLacZ or saline died of liver dysfunction. In the livers of AdTbeta-TR-treated rats, electron microscopy showed: 1) less accumulation of extracellular matrix proteins in the Disse's spaces; 2) regenerated hepatocytes; and 3) fat droplet-rich "quiescent" hepatic stellate cells. Our results demonstrate that TGF-beta plays a critical role in the progression of liver fibrosis, and suggest that anti-TGF-beta intervention should be therapeutic in already-established fibrotic livers, not only by suppressing fibrosis, but by facilitating hepatocyte regeneration.

[Perioperative risk factors in valve surgery concomitant with coronary artery bypass grafting]

Between January 1990 and December 1999, 20 patients underwent the valve surgery concomitant with coronary artery bypass grafting. There were 16 males and 4 females, their mean age was 66.5 years. Of the 20 patients, aortic stenosis was noted in 7, aortic regurgitation in 3, mitral stenosis in one, and mitral regurgitation in 9 patients. The cause of mitral regurgitation was considered to be an ischemic change in six patients, including ruptured papillary muscle due to myocardial infarction in two patients. On the contrary, LMT lesion was recognized in 5, LAD lesion in 17, LCX in 16, and RCA in 12 patients. Seven patients had preoperative myocardial infarction, three patients were required preoperative IABP support. AVR was performed in 10, MVR in 5, and MAP in 5 patients. The number of bypass was 1.9 +/- 0.85. Four patients died of LOS and MOF. The remaining 16 patients have been doing well. The significant difference between the survived and the not survived patients was recognized in the factor of emergency, preoperative IABP, papillary muscle rupture due to myocardial infarction, history of PTCA, LAD lesion, and the time of CPB. The factors regarding coronary artery had the influence on the outcome of a patients of valve surgery concomitant with CABG. Therefore, an appropriate myocardial protection and perioperative management for ischemia were mandatory.

[Surgical results of valvular heart disease combined with myocardial revascularization]

Risk factors for hospital death after combined valvular and coronary artery bypass surgery were examined in 131 consecutive cases between October 1988 and December 1999. These accounted for 8.0% of all 1,644 cases of coronary revascularization surgery and 15.3% of all 854 cases of valvular heart disease surgery. 84 men and 43 women underwent combined valvular and coronary artery bypass surgery. The mean age of the patients was 68.9 +/- 3.9 (22-86) years old. Numbers of cases comprised 58 undergoing aortic valve surgery, 63 undergoing mitral valve surgery, and 10 undergoing eight patients died during hospitalization after the operation: four due to cardiac death and four due to non-cardiac death. We studied pre- and perioperative risk factors for hospital death by means of multivariate analysis. As the major factors, ischemic mitral regurgitation, chronic renal failure, and duration of cardiopulmonary bypass were identified as three major predictors of hospital death. Ischemic mitral regurgitation was the strong predictor (p = 0.03) with 5 hospital deaths out of 38 ischemic mitral regurgitation cases (13.1%), whereas only 3 hospital deaths were seen in 93 other cases (3.2%) operated on in the same period. Over all operation results were not unfavorable, indicating that combined operations may be electively performed if severe coronary artery disease was present. The surgical results with ischemic mitral regurgitation are as yet not well documented and will require further study.

Echocardiographic and pathological evaluation of atherosclerosis in the ascending aorta during coronary artery bypass grafting

We performed intraoperative echocardiography with an epiaortic probe to assess the correlation between echocardiographic appearance and pathological findings of the aorta and to examine the effect of cross-clamping on the aortic wall in 276 patients who underwent coronary artery bypass grafting. The ascending aorta was divided into three segments as follows: lower (L), upper (U), and innominate. The anterior (ant) and posterior (post) intimal thicknesses of each of the three segments were measured. The echogenicity at each of the six locations was examined and was classified as isoechoic or nonisoechoic (hyperechoic, hypoechoic, or mixed type). Tissue punched from the ant L wall of the ascending aorta for vein anastomosis was examined for the presence of atheroma. At the ant L, the prevalence of atheroma was significantly higher in nonisoechoic walls than in isoechoic walls (P = 0.049). We divided patients into two groups according to echogenicity at the U segments. Group A (n = 213) consisted of patients whose echogenicities at both ant U and post U were isoechoic. Group B (n = 63) consisted of patients with nonisoechoic echogenicity at ant U and/or post U. The intimal thicknesses at all six locations in Group B patients were greater than those of Group A (P < 0.01). Deformities at the clamp site after cardiopulmonary bypass were observed significantly more often in Group B than in Group A (P < 0.01). Our data suggest that a nonisoechoic aortic wall indicates more advanced atheroma and a higher risk of deformities at the clamp site. Examination of the echogenicity of the ascending aorta may be one method to reduce perioperative neurological complications.

IMPLICATIONS

We performed epiaortic echocardiography during coronary artery bypass grafting and found that the presence of atheroma and deformities at the cross-clamping site were significantly more prevalent in nonisoechoic walls than isoechoic walls.

Long-term results of root reconstruction using the Carrel patch

OBJECTIVE

The treatment of annuloaortic ectasia in patients, including those with Marfan syndrome, ascending aortic dissection, and other disorders of the ascending aorta and aortic valve presents a surgical challenge that has, unfortunately, shown high hospital mortality up to now. Improvements in graft materials and advanced surgical techniques have, however, begun to reduce hospital mortality.

SUBJECTS AND METHODS

We retrospectively analyzed the records of 47 consecutive patients who undergoing aortic root reconstruction using the Carrel patch between January 1991 and March 1999.

RESULTS

Postoperative complications included myonephrotic metabolic syndrome caused by femoral artery cannulation in 2 patients. Reexploration was done to halt bleeding in 2 patients. In 1 of 4 acute dissection patients, retrograde filling of the false lumen was demonstrated postoperatively. Overall surgical mortality in this series was 2.1% (1 of 47). The cardiac-event free rate was 98% at 5 years and 88% at 8 years. Actual survival is 97.8% at 8 years. No anastomosis complications were seen during follow-up (average: 32.7 months) (about 2.73 years).

CONCLUSION

Surgery is considered feasible in any anatomic variation of aortic root disease, even in coronary ostial minimal dislocation, and the Carrel patch holds hope in preventing of anastomotic pseudaneurysm and ensuring long-term survival. Our experience suggests that modified Bentall operation, or aortic root remodeling using the Carrel patch, has few late-term complications, even in Marfan patients.

Ultrasonographic demonstration of manipulation-related aortic injuries after cardiac surgery

OBJECTIVES

This study was performed to evaluate the frequency and risk factors associated with new aortal lesions induced by surgical manipulation and their correlation with postoperative stroke.

BACKGROUND

Little is known about the causative mechanism of intraoperative atheroembolism after cardiac surgery.

METHODS

Epiaortic echocardiography was performed before cannulation and after decannulation in 472 patients undergoing cardiac surgery with extracorporeal circulation.

RESULTS

A new lesion in the ascending aortal intima was identified in 16 patients (3.4%) after decannulation. New lesions were severe, with mobile lesions or disruption of the intima in 10 patients. Six of the severe lesions were related to aortic damping and the other four to aortic cannulation. Three patients in this group had postoperative stroke. Univariate analysis identified only the maximal thickness of the atheroma near the aorta manipulation site as a predictor of new lesions. The incidence of new lesions was 11.8% if the atheroma was approximately 3 to 4 mm thick and as high as 33.3% if the atheroma was >4 mm, but only 0.8% when it was <3 mm. Total 10 patients (2.1%) sustained neurological complications. Arteriosclerosis obliterans, atherosclerosis of the aorta and new mobile lesions were identified as predictors of strokes.

CONCLUSIONS

This study demonstrated an association between new lesions created by surgical maneuvers and postoperative stroke. Embolic strokes were more likely to occur if new lesions were complicated with intimal disruption, especially of the mobile type. Modifications in surgical procedures will be needed if thick plaque (especially >4 mm) is noted near the manipulation site.

Cardiac operations in patients with severe pulmonary impairment

Many reviews concerning pulmonary complications after cardiac surgical procedures in patients with serious pulmonary disease have been published. However, no strict pulmonary function guidelines were proposed to help the clinician identify the patients at greater risk. We considered whether a low pulmonary function became a risk factor of cardiac operations. We conducted a retrospective analysis of records of 32 patients with severely impaired preoperative pulmonary function who had undergone cardiac operations between July 1988 and March 1999. There was 1 hospital death. The over-all mortality rate was 3.1% (1 of 32). However, this death could not be directly attributed to postoperative pulmonary complications. Postoperative pulmonary complications were seen in 2 patients (6.3%) who required tracheostomy due to atelectasis and pneumonia. No late deaths due to pulmonary complications were observed during the follow-up period. The actual survival rate is 68% at 7 years. A low pulmonary function did not, by itself, become a risk factor of cardiac operations, although a pulmonary function test can be used to alert the clinician to possible postoperative complications, including the requirement of tracheostomy. Especially strict control of postoperative respiration is necessary in patients with forced expiratory volume (FEV) of 1.0 <= 800 ml and/or FEV1.0/BSA <= 600 ml/m2.

Craniocervical and aortic atherosclerosis as neurologic risk factors in coronary surgery

BACKGROUND

Advanced age is associated with increased systemic atherosclerosis and is a consistent neurologic risk factor after coronary artery bypass grafting (CABG).

METHODS

We studied prospectively whether varying degrees of a total atherosclerotic score derived from the brain, carotid arteries, and ascending aorta predicted postoperative neuropsychologic (NP) dysfunction and stroke in 177 elderly patients (> or = 60 years) undergoing CABG.

RESULTS

Group L (low total atherosclerotic score) had rates of NP dysfunction of 25% and 4%, group I (intermediate) had rates of 33% and 22%, and group H (high) had rates of 79% and 43% on postoperative days 1 and 7, respectively (p < 0.001). The incidence of stroke was higher in group H (14.3%) than in groups I and L (7.8% and 0.9%; p = 0.013). Stepwise logistic regression analysis demonstrated the significant predictors of NP dysfunction on postoperative day 7 to be total atherosclerotic score, peripheral vascular disease, and diabetes mellitus, and those of stroke to be total atherosclerotic score, peripheral vascular disease, and hyperlipidemia.

CONCLUSIONS

Perioperative evaluation of craniocervical and aortic atherosclerosis is useful to identify a high-risk patient at postoperative NP dysfunction and stroke after CABG.

Analysis by early angiography of right internal thoracic artery grafting via the transverse sinus : predictors of graft failure

BACKGROUND

There has been debate regarding whether technically demanding right internal thoracic artery (RITA) grafting via the transverse sinus can be extensively applied to patients in high-risk groups, such as patients with a small body size, elderly patients, and woman with relatively smaller coronary artery and internal thoracic artery (ITA) diameters.

METHODS AND RESULTS

Of the 1456 patients who underwent isolated coronary artery bypass grafting between January 1989 and December 1998 at Kumamoto Central Hospital, 393 patients (mean age, 62.4+/-9.0 years) with the RITA anastomosed to the major branches of the circumflex artery were studied. Left ITA grafting was performed in 384 patients, and in 369, the in situ left ITA was anastomosed to the left anterior descending coronary artery using standard methods. Early postoperative angiography was performed in 381 patients. The RITA was occluded in 4 patients, and string-like artery and significant stenosis were present in 11 and 7 patients, respectively; RITA graft patency was thus 94.1%. Of the preoperative variables and angiographic data, simple and multiple logistic regression analyses identified decreased severity of native stenosis, diffuse sclerosis of native vessels, and residual side branches of the ITA as independent predictors of nonfunctional grafts. The method of ITA grafting did not influence the patency of the graft.

CONCLUSIONS

The excellent patency rate demonstrated by this study, the largest angiographic study to date of RITA grafting via the transverse sinus, indicates that this technique can provide reliable revascularization of the left ventricle and that it has the potential to be applied to a wide variety of patients with diseased circumflex arteries.

Coronary artery bypass grafting in dialysis patients

BACKGROUND

To analyze the characteristic problems of coronary artery bypass grafting in patients with chronic renal failure.

METHODS

Fifty-one consecutive dialysis patients who required isolated coronary bypass grafting over a 9-year period were studied retrospectively.

RESULTS

Nine patients (18%) had emergent operation, 4 of whom had intraaortic balloon counterpulsation instituted preoperatively. A mean of 3.3 +/- 1.0 bypasses per patient were grafted; 14 patients (27%) had bypass with two arterial grafts, 13 (25%) of which used left internal mammary artery and gastroepiploic artery and one of which used bilateral internal mammary artery grafts. A mean of 4.2 +/- 2.6 coronary artery segments were calcific according to American Heart Association classification. Eight patients (16%) required operative modifications to avoid manipulating calcific plaques on the ascending aorta. Four patients (7.8%) died, and 15 had nonlethal complications. The actuarial survival rates in 47 hospital survivors at 1, 3, and 5 years were overall 89%, 84%, and 71%, respectively, and estimates for cardiac deaths 93%, 93%, and 82%, respectively. Cardiac event-free rates after coronary artery bypass grafting were 83% and 65% for 3- and 5-year periods, respectively.

CONCLUSIONS

Calcification of coronary arteries and the ascending aorta is a serious problem in long-term dialysis patients. However using arterial grafts, preferentially, in situ, seems to provide a practical alternative to minimize manipulating the ascending aorta during coronary artery bypass grafting, with acceptable perioperative morbidity and mortality rates and long-term survival.

Experimental spinal fusion using sintered bovine bone coated with type I collagen and recombinant human bone morphogenetic protein-2

STUDY DESIGN

Posterolateral lumbar transverse process fusion using recombinant human bone morphogenetic protein (rhBMP)-2 carried by sintered bovine bone and Type I collagen complex was compared with fusion achieved using autogeneous bone graft or sintered bovine bone alone.

OBJECTIVES

This study examined the efficacy of sintered bovine bone coated with Type I collagen as a carrier of rhBMP-2 for lumbar intertransverse process arthrodesis.

SUMMARY OF BACKGROUND DATA

Posterolateral intertransverse process arthrodesis using osteoinductive growth factors is performed experimentally in the lumbar spine. The previous studies revealed the efficacy of osteoinductive factors applied to carriers having no bony structures, such as collagen sheet or polylactic acid polymer, for the spinal fusion. However, in their studies, a large amount of osteoinductive proteins have been applied for the spinal fusion. We used the sintered bovine bone "True Bone Ceramics" (TBC; Koken Co., Tokyo, Japan) coated with type I collagen as the carrier. True Bone Ceramics is the only biomaterial possessing a natural trabecular structure and an organized crystal of bone minerals.

METHODS

Twenty-two adult rabbits underwent bilateral lumbar intertransverse process arthrodesis at L4-L5. The animals were divided into four groups and had materials implanted as follows: autologous bone group, grafted autologous corticocancellous bone harvested from the posterior iliac crest; implanted TBC group; TBC collagen group, implanted TBC coated with Type I collagen infiltrating into the porous space; and BMP group, implanted sintered bovine bone coated with Type I collagen infiltrated with 100 micrograms of rhBMP-2. Spinal fusion was evaluated by radiographic analysis, manual palpation, biomechanical testing, and histologic examination 6 weeks after surgery.

RESULTS

Two rabbits were killed because of infection and lumbar plexus palsy. Radiographs of the BMP group showed a homogeneous fusion mass at the intertransverse area, and stability was confirmed by dynamic radiographs at 3 and 6 weeks after surgery. In the BMP group, a bony mass in the intertransverse area was more prominent than in the other groups. The BMP group had a higher fusion rate based on manual palpation than the-other groups, and BMP fusions showed significantly higher tensile strength and stiffer fusion. The histologic findings in the BMP group demonstrated membranous bone and endochondral bone formations between the transverse process and the fusion mass. In the other groups, continuous trabecular bone formation was observed in the area surrounding the transverse process, but gaps between grafted fragments and less mature bone formation were present in the intertransverse area.

CONCLUSIONS

Sintered bovine bone coated with Type I collagen and rhBMP-2 resulted in a higher fusion rate than the autograft and can be used as a carrier for rhBMP-2 in spinal fusion.

Bileaflet mechanical valve (St. Jude Medical valve) replacement in long-term dialysis patients

BACKGROUND

Few reports exist on the results of bileaflet mechanical valve (St. Jude Medical prosthesis; St. Jude Medical, Inc, St. Paul, MN) replacement in long-term dialysis patients.

METHODS AND RESULTS

We retrospectively reviewed 12 patients, ranging in age from 50 to 86, undergoing long-term renal dialysis who had also undergone mechanical valve replacement at our institution. Operative procedures included aortic valve replacement, aortic and mitral valve replacement, aortic valve replacement and mitral annuloplasty, mitral valve replacement, and modified Bentall's operation. There was 1 hospital death (8.3%). During the mean follow-up period of 37.1 months (range: 5-87 months), there were 2 noncardiac late deaths. Bleeding from the esophageal varix and from a duodenal ulcer occurred in 1 patient with end-stage liver cirrhosis. There were no other major cases of bleeding or cerebrovascular accidents. There were no valve-related complications. All the survivors demonstrated excellent clinical improvement under the NYHA functional classification.

CONCLUSIONS

Our study demonstrated good early and long-term results of mechanical valve replacement in patients undergoing long-term dialysis. These favorable results support the continued use of mechanical valves in dialysis patients.

In situ right internal thoracic artery graft for revascularization of circumflex artery. Early results and long-term angiographic follow up

In 285 patients, the right internal thoracic artery, routed through the transverse sinus, was in most cases anastomosed to the circumflex branches. In 278 cases, the left internal thoracic artery was simultaneously used for revascularization of the left anterior descending artery. Two patients died (mortality rate 0.7%). Postoperative early angiography on 278 patients revealed a high graft patency of 97.8% for the right internal thoracic artery and 96.9% for the left internal thoracic artery. A long-term follow-up study was performed on the first consecutive 115 patients who survived the operation. Seven patients died, 2 due to cardiac causes. Angiographic assessment was performed in 73 patients (67%) at an interval of 28.8 to 93.1 months (mean 58.9 months). Five right internal thoracic arteries were occluded and sledlike right internal thoracic artery grafts were present in 2 patients. Two of them had been confirmed in the previous early study to be not patent. Insufficient data was obtained in 4 patients. The perfect patency rate of the right internal thoracic artery was 89.9% (62/69). Five left internal thoracic arteries were occluded, providing a perfect patency rate of 92.3%. There was no significant difference between the success rate using the right internal thoracic artery and that resulting from using the left internal thoracic artery. We conclude that coronary revascularization using this technique provides good clinical results and excellent early and late patency of the right internal thoracic artery.

[Evaluation of the results of the combined maze procedure for chronic atrial fibrillation with organic heart disease]

To examine the surgical indications and the results of the maze procedure, we reviewed 30 cases who underwent the maze procedure concomitantly with other open heart surgery from October 1995 to October 1997.: the average age was 60.9 years (37 to 75 years) and mean follow up period was 12.3 months (1 to 25 months). The modified maze procedure described by Kosakai and associates was applied in all patients. Twenty one patients (72.4%) regained atrial rhythm and eight patients (27.6%) sustained atrial fibrillation in the follow up periods. The left atrial diameter measured by echocardiography and cardiothoracic ratio were significantly larger in the latter group of patients, compared with those who recovered normal sinus rhythm (63.8 +/- 19.5 versus 51.2 +/- 7.8 mm and 67.7 +/- 8.1 versus 59.2 +/- 5.4%). In order to perform the combined maze procedure, cardiac arrest time and cardiopulmonary bypass time were extended for 56.9 minutes and 65.9 minutes, respectively, compared with the cases without a maze procedure. Four patients (brady atrial fibrillation 2, brady junctional rhythm 1, and complete AV block 1) required permanent pacemaker implantation. There was no operative death, but one patient who underwent the maze procedure and AVR + MAP + TAP died after 4 months due to pulmonary infection, sepsis and multiple organ dysfunction. This patient had shown low output syndrome for 3 days postoperatively. Having considered the data that the preoperative ejection fraction was 51%, cardiopulmonary bypass and cardiac arrest time were 200 min and 165 min respectively, occurrence of low cardiac output had been influenced by prolonged aortic cross-clamp. No late deaths have been observed in follow up period. In conclusion, maze procedure should not be performed in patients who have enlarged left atrium or complex cases requiring relatively longer operative time.

Coronary artery bypass grafting in patients with systemic lupus erythematosus

OBJECTIVE

Few reports exist on the results of coronary artery bypass grafting (CABG) in patients with systemic lupus erythematosus (SLE).

METHODS

We retrospectively reviewed eight CABG in seven SLE patients. In early and late postoperative angiography, all grafts were evaluated for occlusion, development of string sign, or presence of significant stenosis. The early and late results were compared. The pathological studies were performed on the segments of the internal thoracic artery (ITA) and saphenous vein collected from each patient. Atherosclerosis of the ITA was analyzed using the subjective evaluation proposed by Kay et al. (Kay HR, Korns ME, Flemma RJ, Tector AJ, Lepley D. Atherosclerosis of the internal mammary artery. Ann Thorac Surg 21;1976:504-507) scale 0-4 (0 = normal, 1 = minimal disease, 2 = less than 25% luminal narrowing, 3 = 25-50% narrowing, and 4 = greater than 50% narrowing).

RESULTS

The patients consisted of three men and four women with a mean age of 59.8 years. Co-morbid diseases were frequent and there were three patients (37.5%) with renal failure (two dialysis patients, one with renal dysfunction) and two patients with severe atherosclerosis of the aorta. The ITA was used in four patients. Saphenous vein graft was used in seven patients. Concomitant procedures included aortic valve replacement and mitral annuloplasty, mitral valvuloplasty and tricuspid annuloplasty, mitral valve replacement and tricuspid annuloplasty (TAP). There was one hospital death (12.5%). Early patency rates were 87.5% (21/24). No other atherosclerotic changes or stenosis suggesting vasculitis were noted. In pathological studies, there was no significant atherosclerosis in the six ITA specimens from four patients, although three patients had degree two atherosclerosis. No vasculitis was found in ITA or saphenous vein grafts. During the mean follow-up period of 35.3 months (range, 5-91 months), there was one non-cardiac late death. Late restudy (in three patients, 12, 57 and 64 months later respectively) revealed no deterioration in either ITA or vein grafts. Overall prognosis after the operation in SLE patients appears to be good. No other cardiac events were observed, and patients demonstrated marked clinical improvement.

CONCLUSIONS

CABG in SLE patients can be performed with acceptable morbidity and mortality. Our data so far reveals no evidence to preclude the use of ITA and vein grafts in SLE patients.

Extracorporeal circulation before and after ultrasonographic evaluation of the ascending aorta

BACKGROUND

To further gain insight into atheroembolization mechanisms epiaortic two-dimensional echocardiographic evaluation before extracorporeal circulation and after decannulation may be helpful.

METHODS

Epiaortic two-dimensional echocardiography was performed before cannulation and after decannulation in 188 (124 men) patients (mean age, 67.7 years; range, 43 to 86 years) undergoing operation with extracorporeal circulation for ischemic heart disease during 1996.

RESULTS

After decannulation, a new intimal lesion was recognized in 10 of 188 patients (5.3%): mobile type in 5 patients (3 ending with a stroke [60%], 2 having brain computed tomographic scans compatible with embolism), intimal tear in 2, and intimal irregularity in 3 patients. Stroke occurred in a significantly smaller number of patients (2 of 178 [1.1%]; p < 0.001) without new lesions.

CONCLUSIONS

Clamp- or cannula-induced new lesions, especially of mobile type, are often complicated by postoperative stroke. Aggressive surgical technique modifications may need to be considered to avoid creating new lesions, particularly of the mobile type.

Long-term patency rate of right internal thoracic artery bypass via the transverse sinus

BACKGROUND

Although concern regarding patency and possible compromise of graft blood flow by routing the right internal thoracic artery (RITA) through the transverse sinus has been raised, little is known about long-term patency.

METHODS AND RESULTS

To evaluate long-term patency of in situ RITA bypass via the transverse sinus, our first 115 patients (94 men, 21 women; mean age, 62.5 years; range, 13 to 77 years) who were alive in 1998 were enrolled for angiographic study. Only good-caliber grafts with no occlusion, string sign, or significant stenosis were considered patent. Early postoperative angiography had been performed 2 to 3 weeks after surgery in 114 patients. The early patency rates were 97.1% for RITA and 95.4% for left internal thoracic artery (LITA) grafts. Of 109 long-term survivors, 73 (67.0%) consented to have late angiographic restudy at a mean of 59 months (range, 9 to 93 months); 89.9% of RITA and 92.3% of LITA grafts were patent. Cumulative patency rates (actuarial curves) at 6 years were 89.3% (95% CI, 85% to 94%) for RITA and 94.5% (95% CI, 92% to 97%) for LITA, the differences not reaching statistical significance (multivariate Cox analysis).

CONCLUSIONS

Our study demonstrated good long-term patency of in situ RITA bypass grafting via the transverse sinus for revascularization of the circumflex and diagonal arteries and supports its continued use.

[An evaluation of cases carried out by both root reconstruction using Carrel patch method and concomitant procedure]

During the past 7 years from January 1991 to November 1997, we experienced 31 cases of aortic root reconstruction utilizing Carrel patch method. Concomitant procedure were performed in 9 cases of them due to another cardiovascular disease. Complicated cardiovascular disease included 3 cases of ischemic heart disease, 3 cases mitral regurgitation and one case of Aortic arch aneurysm. Several concomitant procedures were performed; 5 cases of CABG, 2 cases of mitral annuloplasty, one case of CABG with mitral valve replacement and one case of aortic arch replacement. The mean extra corporeal circulation time was 190.6 +/- 39.3 minutes and aortic clamp time was 147.8 +/- 34.2 minutes in these 9 cases. There were no significant differences of operative results between the simple root reconstruction group and the concomitant procedure group. We concluded that the aortic root reconstruction using the Carrel patch method has few complications. Although further long-term follow-up is required, our experiences suggest that the aortic root reconstruction with the concomitant procedure can be carry out safely with the aid of appropriate assistance method.

[Mitral valve regurgitation with anterior mitral leaflet chordal rupture or elongation--repair using the flip-over technique]

Repair of prolapsed anterior mitral leaflet has remained technically difficult. The purpose of this study was to assess the clinical results after using the flip-over technique for patients with anterior mitral leaflet prolapse due to dhordal rupture or elongation. Between January 1993 and September 1997, fifteen adult patients with pure mitral valve regurgitation (MR) due to prolapse of the anterior mitral leaflet underwent repair using the flip-over technique. The indication for this procedure were; 1) all mitral structures except the prolapsed area must appear to be intact, and 2) the corresponding chordae attached to the posterior leaflet should be sufficiently strong to be transferred to the anterior leaflet. The prognoses following this technique were retrospectively studied to assess the early and mid-term clinical outcome of this procedure. Follow up was complete in all patients and ranged from 2 to 56 months (with a mean of 25 +/- 17.9 months). There was no hospital death, None required reoperation. One patient died because of acute recurrent MR during follow-up. No other complication was experienced. Doppler echocardiographic studies at the final follow-up showed less than mild regurgitation in 11 (78.6%) of the 14 surviving patients. We believe that this procedure was effective for that the obtained repair of a prolapsed anterior mitral valve and early and mid-term clinical outcome from this procedure has been satisfactory.

[Separate operation for extensive aneurysm (mega-aorta) complicated with ischemic heart disease]

A seventy one year-old woman, who had an arch and thoracoabdominal aortic aneurysm (type II according to Crawford classification) with ischemic heart disease, underwent a separate operation using the elephant trunk method. At first, she underwent the ascending aorta and arch replacement the with elephant trunk technique, and, underwent CABG simulutaneously utilizing the separate extra corporeal circulation and hypothermic circulatory arrest. The Chest and abdominal CT revealed the enlargement of abdominal aortic aneurysm 5 months after operation. The second operation was performed using Stoney's spiral opening method and the revasculization of spinal arteries (Th6, 7 and Th9) underwent the segmental aortic clamping to prevent spinal cord ischemia. Furthermore, the second operation was performed using selective perfusion to visceral arteries and F-F bypass for the prevention of visceral ischemia. Each flow rate by selective perfusion in major abdominal blanches was from 50 to 100 ml/min. Therefore, hepatorenal dysfunction and paraparesis did not occur after the second operation. It was suggested that the segmental aortic clamping and the selective perfusion to visceral arteries with F-F bypass may be effective to prevent the ischemia of the spinal cord and abdominal organs.

A case-control study on male hepatocellular carcinoma based on hospital and community controls

A case control study on male primary hepatocellular carcinoma(HCC) and hepatitis B or C virus and some potential risk factors, e.g. blood transfusion, aldehyde dehydrogenase 2(ALDH2) genotype and drinking habits, was performed using two controls, i.e. a hospital control(HC) and a community control(CC) in Fukuoka and Saga Prefectures. Cases were obtained from the Second Department of Internal Medicine, Kurume University Hospital. The HCs were obtained from inpatients of two general hospitals in Kurume and the CCs were randomly sampled from the Kurume citizens being matched with age and sex to each case. Based on the HCs, odds ratios(ORs) of developing male HCC were statistically significant due to HBsAg or anti-HCV antibody positive status. Some discrepancies were observed between the two controls, i.e. higher proportions of past histories of diabetes or hypertension, of ALDH2 typical homozygote(ALDH2(1)/ALDH2(1)), and of heavy drinkers among the HCs, suggesting slight deviation of the HCs from the CCs in alcohol related aspects. Although ORs regarding accumulated amount of alcohol intake by age 40 based on the HCs were insignificant, two of the three corresponding ORs based on the CCs were statistically significant. Judging from alcohol related aspects between the two controls, the ORs for alcohol based on the HCs seems to be underestimated.