Yasuo Takeuchi

Partial median sternotomy as a minimal access for off-pump coronary artery bypass grafting: feasibility of the lower-end sternal splitting approach

BACKGROUNDnOff-pump coronary artery bypass grafting (OPCAB) can be performed in several ways using a minimally invasive approach (MIDCAB). Using the left anterior small thoracotomy (LAST) approach, only the LAD can be grafted. To expand the indications for MIDCAB from single-vessel disease to double-vessel disease, we have used a partial sternotomy without a transverse cut, namely, the lower-end sternal splitting (LESS) approach. Through this approach, the LAD and RCA can be revascularized by means of a single small incision without the risk of damaging the tissue around the intercostal space during harvesting of ITA when the sternum is transversely divided. The purpose of this study was to demonstrate the feasibility and safety of this technique.nnnMETHODSnBetween November 1999 and November 2000, a total of 22 patients underwent MIDCAB through a lower midline skin incision from the fourth intercostal space to the xiphoid process with longitudinal division of the lower half sternum up to the 3rd rib, without either a T- or reversed L-shaped division of the sternum. Of the patients, 14 had LAD disease only, 5 had both LAD and RCA disease, 2 had RCA disease only, and 1 had left main trunk disease. Two of the operations were of redo coronary artery bypass grafting. The mean age was 69.5 +/- 6.1 years (range 58 to 77 years).nnnRESULTSnThe mean length of the skin incision was 8.5 +/- 1.4 cm (range 7 to 12 cm). No hospital death or morbidity was observed. All patients had arterial conduits: LIMA in 20 patients, RIMA in 3, RGEA in 4, and RA in 1. The mean number of grafts per patient was 1.3 +/- 0.6 (range 1 to 3). No blood transfusion was required perioperatively. The patency rate was 96%. All patients were in New York Heart Association class I and no wound complications or postoperative pain occurred during follow-up.nnnCONCLUSIONSnOur experience demonstrates that the LESS approach for MIDCAB is technically feasible for revascularizing not only the LAD but also the RCA system, with the same small incision using IMA and GEA. It can be used with excellent cosmetic results and safety. Although our experience is limited, we conclude that this less invasive surgical technique can be used as an alternative approach for MIDCAB in patients with LAD or RCA disease.

Experimental assessment of the drainage capacity of small silastic chest drains.

Recently, flexible fluted small silicone drains have been used widely as chest drains after cardiac surgery. Despite the clinical advantages of using smaller silastic chest drains over conventional chest tubes, an experimental comparison of the drainage capacity between these two drain tubes has not yet been performed. The drainage capacity of 19F silicone drains and 28F conventional tubes was tested. In an in vitro study, both tubes were set in a water bath and drained at a pressure of 10 mm Hg. In an in vivo study, the drains were inserted into the hemithorax in 8 adult pigs. Blood was infused at 20 mL·min−1 into both chest cavities and the tubes were drained at 15 cm H2O for 30 min. In the in vitro study, the drainage capacity of the conventional chest tube was 9-times higher than that of the smaller silicone drain (103.8 vs. 11.6 L·hr −1). However, in the in vivo study, there was no difference in drainage capacity between the two different tubes over time. This experiment demonstrated that the smaller silastic chest drain has sufficient drainage capacity, almost identical to the conventional chest tube, in the clinical setting.

Clinical experience with Smart Care after off-pump coronary artery bypass for early extubation.

The purpose of this study was to compare the intubation time using Smart Care, a knowledge-based system for automated weaning, with that of conventional physician-controlled weaning after off-pump coronary artery bypass (OPCAB) and to determine the efficacy of Smart Care. During 2004, 53 sequential patients were scheduled for isolated coronary artery bypass grafting without cardiopulmonary bypass. Patients were divided into two groups: the Smart Care group (n = 10) and the control group (n = 35). Eight patients requiring hemodialysis and patients undergoing the awake OPCAB method were excluded. The intubation times were 172.6 ± 51.6u2009min in the Smart Care group compared with 342.0 ± 239.0u2009min in the control group (P = 0.032). No specific complications occurred with this computer-driven expert weaning system. In conclusion, the Smart Care system reduced the duration of mechanical ventilation and the respiratory care workload. This system was effective in the care of patients without complications requiring mechanical ventilation after OPCAB.

Tricuspid valve replacement after cardiac transplantation

Tricuspid regurgitation, a fairly common finding after cardiac transplantation, is generally mild or moderate, and is not clinically significant. The etiology of tricuspid regurgitation is not entirely understood, and experience with valve replacement after cardiac transplantation is limited. We describe a case of progressively severe tricuspid regurgitation ultimately requiring tricuspid valve replacement. At operation, the ruptured chordae of the posterior part of anterior and septal leaflet with resulting partially flail leaflets were found. Examination of the papillary muscle showed origins of several of the ruptured chordae. Damage to the tricuspid subvalvular apparatus at endomyocardial biopsy appeared to be a possible cause. A 31-mm Carpentier-Edwards porcine valve was implanted. This was because replacement with a mechanical prosthesis would prevent future right-side heart catheterization and endomyocardial biopsy and in valve repair, the patient remains exposed to the risk of the recurrence of chordal rupture. We discuss proposed causes and choices in surgical technique.

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.

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.

Lower sternal splitting approach for off-pump coronary artery bypass grafting

There are several ways to revascularize coronary arteries without cardiopulmonary bypass using a minimally invasive method. Currently, one of the most commonly used methods is minimally invasive direct coronary artery bypass (MIDCAB) through a left thoracotomy. Using this technique, however, only the left anterior descending and diagonal branch can be grafted. This article describes coronary revascularization of the left anterior descending artery or right coronary artery, or both, via a lower ministernotomy without a transverse cut, namely, the lower sternal splitting method. Through this approach, the left anterior descending, diagonal, and right coronary arteries can be revascularized using a single, minimally invasive approach without the risk of damaging the tissue around the intercostal space when the sternum is transversely divided.

Long-term results after Starr-Edwards mitral valve replacement in children aged 5 years or younger

BACKGROUNDnMitral valve replacement with prosthetic valves in infants and children requires consideration of multiple variables. When we examined our late follow-up, the effect of the growth of the patient relative to the size of the prosthesis placed was the most important variable predicting late successful results. We reviewed our experience with mitral valve replacement using the Starr-Edwards ball valve in children aged 5 years or younger, focusing on the effect of valve prosthesis-patient mismatch on the long-term results in the growing patient.nnnMETHODSnFrom August 1974 to June 1986, 8 patients aged 5 years or younger underwent mitral valve replacements using the Starr-Edwards prosthesis size OM in 3 patients and 1M in 5 patients. Model 6320 was used in 1 patient and Model 6120 in the remaining 7 patients.nnnRESULTSnFollow-up was 100% from 15 to 27 years (mean, 20 years). No valve-related complications of thromboembolism, anticoagulant-related hemorrhage, or prosthetic valve endocarditis were seen. All patients normally developed to adult size. The range of the valve area index of the 3 patients who received the smaller Starr-Edwards valve (size OM) was 0.97 to 1.24 cm2/m2. Although this size valve was adequate for patient growth to adolescence, in each case valve replacement with a larger valve was required.nnnCONCLUSIONSnOur long-term review of Starr-Edwards ball valve mitral valve replacement in children aged 5 years or younger shows that the Starr-Edwards ball valve (Models 6320 [1 patient] and 6120 [7 patients]) showed excellent durability, no thromboembolism, and no anticoagulant-related complications. Size OM valves required replacement for hemodynamic reasons because of patient growth; larger size 1M valves remained hemodynamically satisfactory in spite of patient growth.

Histopathology of the longest-lived saphenous vein graft in a patient with Kawasaki disease.

The patency rate of saphenous vein grafts (SVGs) for children with Kawasaki disease (KD) tends to decline during the early years after coronary artery bypass grafting (CABG). Although degenerative changes have been considered the main cause of SVG occlusion, there have been no reports on the histopathologic features of the SVG in patients with KD. We herein describe a redo off-pump total arterial revascularization in a 43-year-old man with KD, 34 years after the first CABG using SVG. The histopathologic examination of the longest-lived SVG demonstrated that graft occlusion was mainly caused by the diffuse intimal hyperplasia.

Surgically treated aortic root aneurysm following aortic valve replacement.

A 65-year-old man with aortic regurgitation underwent aortic valve replacement with a St. Jude Medical prosthetic valve about 6 years ago. At that time, the aortic root was slightly dilated at about 40 mm in diameter and the ascending aorta was within the normal range. This year, the man was diagnosed with an aortic root aneurysm in regular follow-up echocardiography. Chest-enhanced computed tomography and chest aortography at our hospital demonstrated a pear-like aortic root aneurysm about 60 mm in diameter. Elective operation for the aortic root aneurysm was conducted September 29, 1999, based on the Bentall procedure. Composite graft replacement with coronary reconstruction was conducted using a 28-mm Hemashield prosthetic graft and a 23-mm St. Jude Medical prosthetic valve under cardiopulmonary bypass. An 8-mm Hemashield graft was interposed on the left main coronary artery and the right coronary artery was directly anastomosed using a Carrel patch method. The postoperative course was uneventful and post-operative examination demonstrated good surgical results. Histological findings of the aortic aneurysm wall showed cystic medial necrosis. Surgical cases of aortic root aneurysm after aortic valve replacement are rare, but serious complications with the possibility of rupture or dissection warrant surgical intervention.