Min-Ho Song

Intraoperative heart rate variability of a cardiac surgeon himself in coronary artery bypass grafting surgery

The mental strain of a cardiac surgeon may differ when he performs coronary surgery from and when he only assists in performing coronary surgery. In 50 selected cases of on-pump heart arrested coronary artery bypass grafting (CABG), an attending-consultant surgeon performed 30 procedures of CABG (Group A) and an attending-consultant surgeon supervised the remaining 20 cases of CABG performed by two resident surgeons (Group B). Intraoperative Holter electrocardiograms of the attending-consultant surgeon were recorded and analyzed for heart rate variability (HRV). In Group A, the ratio of low frequency to high frequency was at a peak in the beginning of the operation and gradually decreased toward the end of the operation. In Group B, the ratio of low frequency to high frequency was at a peak in the phase of aortic cross-clamp, coronary anastomosis, and unclamping. When an attending-consultant surgeon performed the operation himself, the most anxious part of the operation was at the beginning and thereafter the level of anxiety gradually declined. In contrast, when he assisted a resident, the highest level of anxiety was when the aortic cross-clamp was in place and out of place and during the coronary anastomosis.

Three-Dimensional Simulation of the Blalock-Taussig Shunt Using Computational Fluid Dynamics

Abstract To examine blood flow after the placement of a Blalock-Taussig shunt, three complex T-figure models were developed according to shunt size and the degree of pulmonary artery hypoplasia. With the use of computational fluid dynamics, the net energy loss and wall shear stress were calculated under pulsatile conditions. We calculated that the 5-mm shunt carried the least energy loss, but the most wall shear stress. In this simulation, the 5-mm shunt was thought to be superior to the 4-mm and 3-mm shunts in terms of energy loss and smooth flow, but it produced high wall shear stress.

Giant vegetation mimicking cardiac tumor in tricuspid valve endocarditis after catheter ablation

A 33-year-old man suffered from fever of unknown origin and developed right-sided heart failure. A transeshophageal echocardiogram revealed an progressive enlarging mass in the right atrium mainly attached to the tricuspid valve and a previous ablation site, which mimicked a cardiogenic tumor. He was operated on to remove the mass and intraoperative pathology showed it was large vegetation and secondary granulation due to tricuspid endocarditis. Tricuspid valve replacement was performed combined with reconstruction of the right atrial wall.

Echocardiographic Evaluation of Internal Mammary Artery Graft Patency

The feasibility of using transthoracic echocardiography to assess internal mammary artery graft patency and function was examined. Coronary angiography and transthoracic echocardiography was performed in 60 consecutive patients undergoing coronary artery bypass from April 2000 to March 2002. Flow velocity, velocity-time integral, and the ratio of the diastolic fraction of the velocity-time integral to total velocity-time integral were measured by doppler transthoracic echocardiography. A stress test was carried out to detect coronary flow changes by echocardiography. The relationship between the coronary angiogram and the echocardiogram was analyzed. The overall graft patency rate was 98%. The mean diastolic velocity-time integral in patients with patent grafts was 0.64, and it increased up to 0.72 in response to physical stress. The occluded grafts showed diastolic velocity-time integral fractions of less than 0.60 in all grafts. There was a statistical correlation between patency ≥ FitzGibbon grade B and diastolic velocity-time integral > 0.60. The diastolic velocity-time integral recorded by transthoracic echocardiography predicted the patency of internal mammary artery grafts. As echocardiography is noninvasive and accurate, it might be a useful method of verifying arterial graft patency.

Revival of the side-to-side approach for distal coronary anastomosis

Side-to-side anastomosis was employed by just ten proportional stitches while performing distal anastomosis during coronary artery surgery. This technique is simple and quick. Here this simple technique is described in detail and the postoperative status of grafted conduits is reported.

Learning Curve of Arch-First Technique Analyzed by Cumulative Sum

This study was undertaken to verify efficacy of the arch-first technique in the light of its learning curve. From April 2002 to September 2005, 10 consecutive elective cases of total arch replacement were retrospectively examined. The learning curve of the arch-first technique was constructed using cumulative sum analysis. There were no operative deaths. The mean deep hypothermic circulatory arrest time was 28.4 ± 13.7 min, the lower body ischemic time was 91.3 ± 35.1 min, aortic cross clamp time was 133.2 ± 18.1 min, cardiopulmonary bypass time was 198.8 ± 21.5 min, and operation time was 383 ± 24 min. The durations of deep hypothermic circulatory arrest, bypass, and operation were under the 90% lower alarm line in all 10 cases. The lower body ischemic time and cardiac arrest time were between the 80% upper and lower alert lines. Cumulative sum analysis of total arch replacement using the arch-first technique showed satisfactory rates of improvement in reconstruction of the 3 arch vessels, cardiopulmonary bypass time, and overall mortality.

A simple training model for coronary artery anastomoses.

To provide supplementary training for trainee cardiac surgeons, a simple method is required to simulate coronary anastomoses. By stretching 2 gloves over a towel, a model can be made that can be used to simulate a small coronary arteriotomy (including anterior and posterior walls). The graft can also be simulated using the fingers of the gloves.

Successful off-pump coronary artery bypass for Behcet's disease.

A 66-year-old woman with a 30-year history of Behcets disease was referred for coronary surgery because of restenosed stent and crescendo angina. We succeeded in operating on her by off-pump coronary bypass with bilateral internal mammary arteries, which were anastomosed to the left anterior descending artery and diagonal artery. The grafts were patent postoperatively and she became free from angina. Coronary surgery for Behcets disease is extremely rare and this experience prompted us to report this case.

Aortic root aneurysm in Takayasu arteritis syndrome: Exploration in active phase and repair in inactive phase

It is a matter of difficult decision when to operate on aortic root aneurysm due to Takayasu arteritis because Takayasu arteritis bears in itself an inflammatory character which makes a cardiac surgeon to be careful to circumvent lethal complications such as hemorrhage, pseudoaneurysm formation, valve and suture line detachment, and paravalvular leakage. We recently cased for a case of fragile and inflamed aorta of aortic root aneurysm in Takayasu arteritis in inflammatory active phase which ended in exploration, and it was radically repaired in inflammatory inactive phase six months after steroid administration. This experience prompted us to report.

A Simple Method of Inspection of Proximal Bleeding in Bentall Procedure

A simple method of checking for bleeding from the proximal anastomosis site in Bentall operations is described. After suturing a Carbo-Seal prosthesis to the aortic annulus, using a folding-over technique, the left ventricle is filled with cardioplegic solution through the prosthetic valve, and the heart is massaged to visualize possible leaks at the level of the suture.