[Non-compromised grafting policy in off-pump coronary artery bypass].

BACKGROUND: The off-pump coronary artery bypass (OPCAB) has been prevalent around the world. However the most optimal selection of graft conduits has still been controversial. METHODS: Between January 2002 and April 2003, 126 consecutive isolated coronary artery bypass procedures were attempted to performed without cardiopulmonary bypass. A mean age of the patients was 69.3 (47-90). Fifteen patients were operated on emergently and 16 were urgently, including 15 patients requiring preoperative intra-aortic balloon pumping (IABP). Five patients underwent reoperative coronary bypass. RESULTS: All procedures were completed without cardiopulmonary bypass. The mean number of grafts per patient was 3.23 (range, 1 to 6). The skeletonized arterial conduits were aggressively used [117 left internal mammary artery (LIMA) to 155 sites, 70 right internal mammary artery (RIMA) to 79 sites, 57 right gastro-epiploic artery (RGEA) to 82 sites and 49 saphenous vein (SV) to 91 sites]. Cardiac-related hospital mortality was none. Angiographic assessment of grafts demonstrated that patency of LIMA, RIMA, RGEA and SV were 98.6%, 100%, 100%, and 97.6% respectively. CONCLUSION: OPCAB with skeletonized in situ arterial conduits is secure and feasible.

[Multivessel off-pump coronary aortic bypass grafting with an impaired and severely dilated left ventricle using the Starfish heart positioner].

Off-pump coronary artery bypass grafting (OPCAB) is gaining acceptance and is now more widely used for coronary revascularization worldwide. Accessing the vessels, particularly on the lateral and inferior walls of the heart, can sometimes be challenging while the heart is beating, especially in hearts with an impaired and severely dilated left ventricle. The Starfish heart positioner was designed to achieve optimal exposure of the lateral and inferior walls of the heart with minimal hemodynamic compromise. This device was used in a patient with a severely impaired and dilated left ventricle to successfully position the heart for quadruple bypass grafting using all in situ arterial grafts, such as bilateral international thoracic arteries (ITAs) and the right gastroepiploic artery. The degree of hematoma caused by the pressure of the suction cup of this device was minimal. This case report suggests that the use of Starfish heart positioner will facilitate and expand the ability of surgeons to easily and consistently perform OPCAB.

[Coronary artery bypass-grafting using interrupted anastomosis with the U-clip].

For coronary artery anastomosis, the continuous suture technique is generally used because it is easy to perform, there is less anastomotic leakage, and a shorter anastomotic time compared with the interrupted suture technique. However, with this technique there is a potential risk of anastomotic stenosis caused by the purse-string effect, which does not occur with the interrupted suture technique. The U-Clip device was designed to facilitate the interrupted suture technique in coronary anastomosis by eliminating the need for suture management, knot tying, and surgical assistance. The device employs the superelastic properties of nitinol and two components: 1. a needle/suture delivery system, and 2. a detachable nitinol self-closing wire. We used this device successfully for LITA-LAD anastomosis in MIDCAB. When this device is applied to small caliber conduits, such as the internal thoracic arteries and the gastroepiploic artery, the side-to-side anastomosis can reduce the anastomotic leakage more efficiently, since the coronary incision and graft incision can be perfectly matched. The U-Clip facilitates coronary anastomosis by simplifying and decreasing the amount of manipulation and complexity required in minimally invasive CABG procedures. Nitinol technology also has potential in robotic and endoscopic surgical applications.

Coexistence of lung cancer and hamartoma.

We present a rare case of a synchronous primary lung cancer adjacent to a hamartoma. A 71-year-old woman was admitted with congestive heart failure due to acute myocardial infarction. A chest radiogram on admission showed pulmonary edema with a tumor shadow in the right upper lung field. Because histological diagnosis was not obtained preoperatively, a wedge resection of the lung was conducted using video-assisted thoracoscopic surgery. The histopathological examination confirmed the coexistence of an adenocarcinoma with a chondromatous hamartoma. Right upper lobectomy was performed followed by excision of the mediastinal lymph nodes. Although hamartoma is generally considered to be a benign neoplasm, there have been several reports of increased risk to lung cancer in patients with a chondromatous hamartoma. Therefore, we recommend that patients with a hamartoma should be submitted to a complete evaluation and to regular follow-up, considering the risk to associated synchronous malignancy.

[Lower-end sternal splitting (LESS) approach as a new strategy for minimally invasive off-pump CABG].

There are several ways to perform off-pump coronary artery bypass grafting (OPCAB) using a minimally invasive method. Currently, one of the most commonly used approaches is left anterior small thoracotomy (LAST). However, using this approach, only the LAD can be grafted. We have employed a partial sternotomy without a transverse cut, namely, the lower-end sternal splitting (LESS) approach for OPCAB. Through this approach, the LAD and RCA can be revascularized via a single small incision without the risk of damaging the tissue around the intercostal space when the sternum is transversely divided. Since November 1999 to September 2000, we have applied OPCAB through LESS approach in 17 patients. Mean age was 70.0 + 5.4 years (range 58-77), and 13 were men. Mean length of the skin incision was 8.6 + 1.2 cm (range 8-11). No hospital death or morbidity was observed. No patient required blood transfusion. All had arterial conduits: LITA-LAD, in 11; LITA-LAD, RITA-RCA, in 1; LITA-LAD, GEA-PDA, in 2; LITA-LAD, RITA-RCA, RITA-RA-PDA, in 1; and GEA-PDA, in 2. All underwent postoperative coronary angiography, and the patency rate was 95.5%. Our experience demonstrates that the LESS approach for OPCAB is technically feasible and can be used with excellent cosmetic results and safety. Although experience is limited, this less invasive surgical technique can be used as an alternative approach for MIDCAB in patients with LAD and/or RCA disease.

Changes in ultra-low and very low frequency heart rate variability after coronary artery bypass grafting.

This study was performed to assess the effects of coronary artery bypass grafting (CABG) on the ultra-low (ULF) and very low (VLF) frequency components of heart rate variability (HRV). Forty-nine CABG patients (aged from 38 to 77 years) were examined by 24-h ambulatory electrocardiographic (AECG) monitoring, both preoperatively and 4 weeks after CABG. HRV spectral components were obtained by maximum entropy method analysis. Then the ULF, VLF, low frequency (LF), high frequency (HF) and total frequency (TF) components were compared before and after CABG. The average 24-h heart rate increased significantly after CABG (69+/-11.5 vs 82.9+/-10.9 beats per minute [bpm], P < 0.0001). The power of the ULF, VLF, and LF spectral components showed a decrease after surgery (2,859.9 vs 1,601.2 ms2, P<0.0001, 1,215.0 vs 572.3 ms2, P<0.0001, and 260.3 vs 125.9 ms2, P< 0.002, respectively), but the HF power did not show any significant change (98.7 vs 125.9 ms2, NS). Analysis of the normalized ratio of the ULF component (ULF/TF ratio) revealed a significant increase postoperatively (0.6496+/-0.0931 vs 0.7003+/-0.1338, P < 0.0001), but the VLF/TF and LF/TF ratios decreased after CABG (from 0.2671+/-0.0689 to 0.2040+/-0.0832, P< 0.0001 and from 0.0568+/-0.0290 to 0.0429+/-0.0232, P< 0.0088, respectively). In contrast, there was no significant alteration in the HF/TF ratio. These results suggest that recovery of cardiac autonomic activity is delayed after surgery. However, improvement of the ULF/TF ratio, one of the prognostic indicators for patients with cardiac disease, should be related to the relief of myocardial ischemia by CABG.

Twenty-two-year follow-up of saphenous vein grafts in pediatric Kawasaki disease.

We describe 2 Kawasaki disease patients with excellent long-term patency of saphenous vein grafts, who underwent coronary artery bypass at age 7 and 9 years, respectively, and demonstrated normal growth during 22 years of follow-up. The grafts showed no deterioration and played an important role in coronary blood supply.

Galpha16 mimics vasoconstrictor action to induce smooth muscle alpha-actin in vascular smooth muscle cells through a Jun-NH2-terminal kinase-dependent pathway.

Prolonged exposure of vascular smooth muscle cells (VSMC) to vasoconstrictors such as vasopressin or angiotensin II induces hypertrophy and increases expression of muscle-specific genes including smooth muscle alpha-actin (SM-alpha-actin). These vasoconstrictors signal through G-proteins, including members of the Gq family. To further investigate the role of Gq family members, VSMC were transfected with a constitutively active mutant of a Gq family member, Galpha16 (Galpha16Q212L). Stable expression of Galpha16Q212L persistently stimulated phospholipase C, resulting in increased basal levels of inositol phosphates. These cells were hypertrophied and expressed elevated levels of SM-alpha-actin compared with wild-type VSMC or cells transfected with a control plasmid (Neo). SM-alpha-actin promoter activity was markedly increased in cells stably or transiently expressing Galpha16Q212L. Basal c-Jun-NH2-terminal kinase (JNK) activity was increased 3-9-fold in cells stably expressing Galpha16Q212L, while basal activity of the p42/44 mitogen-activated protein kinases (ERKs) was unaffected. Transient expression of a kinase inactive JNK kinase partially inhibited induction of SM-alpha-actin promoter activity in response to vasoconstrictors or expression of Galpha16Q212L. These results indicate that expression of constitutively active Galpha16 in VSMC mimics the effects of vasoconstrictors on hypertrophy and muscle-specific gene expression, and activation of JNK may play a role in these responses.

Changes in diastolic regional stiffness of the left ventricle before and after coronary artery bypass grafting.

To evaluate the effect of coronary artery bypass grafting (CABG) on regional diastolic function of the left ventricular wall, we applied the concept of the stiffness constant to the diastolic sigma-ln (1/H) relation, where sigma is the mean wall stress, and H is the wall thickness of the region of concern, and ln (1/H) is the natural logarithm of the reciprocal of wall thickness. We assessed 12 cardiac regions in six patients with coronary artery disease who underwent CABG at the Cardiovascular Hospital of Central Japan between May 1994 and January 1995. Left ventricular pressure and regional wall thickness were measured simultaneously, with a micromanometer-tipped catheter and by two-dimensional echocardiography, respectively, before and after CABG. The stiffness constant (K) was obtained by fitting the diastolic sigma-ln (1/H) data points to an exponential curve with zero asymptote: sigma = Cexp[Kln (1/H)]. Preoperatively, the stiffness constant in the affected region (CABG region) was greater than that in the unaffected region (non-CABG region) (4.79 +/- 2.56 vs 2.95 +/- 0.72). Postoperatively, the stiffness constant in the CABG region was significantly decreased, to 3.21 +/- 1.22. The stiffness constant, which is derived from the sigma-ln (1/H) relation, is useful for the assessment of LV regional diastolic function.

[Effect of coronary artery bypass grafting on left ventricular diastolic function in coronary artery disease--an assessment using pulsed Doppler echocardiography].

To evaluate the effect of coronary artery bypass grafting (CABG) on left ventricular (LV) diastolic function in coronary artery disease (CAD), pulsed Doppler echocardiography was performed in the patients undergoing CABG between February 1991 and March 1993. The patients with non-sinus rhythm, more than 100 heart beats/min, aortic or mitral valvular disease, and perioperative myocardial infarction or left ventricular aneurysm were excluded from this study. CAD group consisted of 24 patients and Control group 17 normal subjects with no evidence of angina nor ischemic findings on electrocardiogram. No significant differences were found in heart rate, mean blood pressure, left atrial dimension and LV ejection fraction in two groups. Pulsed Doppler echocardiographic examinations showed that in comparison with Control group, E/A ratio was decreased (0.72 vs 0.89, p < 0.05) and IRT prolonged (115.9 vs 92.4, p < 0.05) in CAD group. These results indicated impaired diastolic function in CAD patients. In CAD group, echocardiographic study was performed 3 to 4 weeks after CABG. In 16 patients in whom heart rates at the pre- and the postoperative examinations were relatively identical, E/A ratio increased postoperatively from 0.66 to 0.96 (p < 0.001) and IRT and DHT shortened from 115.2 ms to 86.6 ms (p < 0.001) and from 96.3 ms to 82.4 ms (p < 0.05) respectively. In addition, DC increased from 2.04 cm/s2 to 3.02 cm/s2 (p < 0.005) postoperatively. The results indicated that CABG improved LV diastolic function in CAD patients. In summery, this study indicated that impaired LV diastolic filling was found in CAD patients and that CABG improved LV diastolic function in CAD patients.

[A case of mitral valve replacement due to mitral regurgitation after percutaneous transvenous mitral commissurotomy (PTMC)].

A 58-year-old woman, who had congestive heart failure due to mitral regurgitation after percutaneous transvenous mitral commissurotomy, underwent mitral valve replacement. It is reported that mitral regurgitation more often occurs after PTMC in patients with severely calcified mitral valve or advanced subvalvular lesion than in those without. Our experience indicated that PTMC should be carefully performed in institutions which have a surgical team ready for emergency operation.