Retrograde cerebral perfusion has been a useful technique for preventing brain damage during hypothermic circulatory arrest. To determine the optimum conditions for retrograde cerebral perfusion utilizing a fluorescence vital microscope, male Wistar rats weighing 100 to 300g were used for infusing saline with contrast medium (0.01% FITC-albumin) through the external jugular vein. A closed cranial window was prepared over the pial surface of the brain at the medial part of the right parietal cortex in order to observe the blood flow of tributaries from the middle cerebral artery to the superior cerebral vein. Intracranial pressure was controlled at 3±2cmH₂O for comfortable visualization. The observation of retrograde cerebral perfusion was performed under hypothermic conditions. Cerebral blood flow could not be observed under retrograde pressure of 5-15mmHg, mainly due to venovenous shunt flow. But retrograde cerebral perfusion was observed with a driving pressure of 15-30mmHg, and flow velocity measured by the video tracing method (n=5) in arterioles (mean diameter 37±10μm) was -12±5μm/sec, in venules (mean diameter 64±17μm) was -14±9μm/sec, which was 405±92μm/sec and 220±150μm/ sec under hypothermic beating heart conditions respectively. Under retrograde pressure of 30-50mmHg, cerebral microcirculation was deteriorated with increasing cerebral volume, and cerebral blood flow was consequently interrupted. In conclusion, the optimal condition for retrograde cerebral perfusion was determined under retrograde perfusion pressure of 15-30mmHg and intracranial pressure of 3±2cmH₂O, whenever cerebral microcirculation from venule to arterioles was best. Retrograde cerebral perfusion has some advantage for cerebral protection compared with hypothermic circulatory arrest, but might not supply sufficient cerebral blood flow to prevent brain damage.

Shooting an arrow is a typical example of the physiological neck reflex. To get a good record in the archery competition, highly reproducible release is required during the drawing of a bow.
In this study, first, the mechanics of shooting were analysed by means of EMG, progressive photographing and bow strain signals, employing two groups of college student archers (semi-skilled and unskilled) . These results were compared with those of the world top-class archers. And second, the rate of muscle silent period appearance, its latent time and release reaction time were measured from the three groups of college student archers (skilled, semi-skilled and unskilled) . The following results were obtained:
1. Some distinct differences were recognized in muscle activities during shooting, such as “set up”, “draw”, “full draw”, “release” and “follow through” between the top-class archers and college archers (semi-skilled and unskilled) .
2. In the case of two top-class archers, muscle silent period prior to release was observed in m. deltoideus (pars acrominalis) of both arms and m. trapezius (pars transversa) of the pushing arm.
3. In the skilled college student archers, high rate of silent period appearance (70-100%) were observed and the values of its latent time and release reaction time falled in a very narrow range of 110-120 msec and 170-180 msec, respectively.
4. Before the release, when m. deltoideus of the pulling arm was silent, ipsilateral m. trapezius began action. This muscle activity was cleary observed almost only in the case of skilled archers. Hence, this pattern of muscle activity may be accomplished by long time training.

We performed surgical correction of a single atrium in a 46-year-old man, who had suffered from congestive heart failure (NYHA II) and pulmonary hypertension (58/23 (36) /mmHg). An intra-atrial shunt (L-R 71%, R-L 14%) due to single atrium and mild mitral and tricuspid regurgitation were detected. The operation consisted of making a new atrial septum with an autologous pericardial patch and direct mitral cleft suture. The post-operative course was uneventful.

Injury to the thoracic aorta is often fatal. We encountered a case of aortic rupture caused by a traffic accident. A 20-year-old man was transferred to our hospital because of right elbow fracture and enlargement of the upper mediastinum on X-ray. We diagnosed aortic isthmus rupture by chest CT with enhancement. He did not have chest pain, but complained of severe pain in the right elbow. His hemodynamic condition was stable, but his right arm become swollen with increasing sensory disturbance. Chest CT and blood cell count showed no interval change between results at a previous hospital and ours. So we decided to operate on his right arm before aortic rupture. After the open reduction of his fractured elbow, pleural effusion increased although his hemodynamic condition was stable. Then the descending aorta was replaced under partial cardio-pulmonary bypass. His post-operative course was uneventful.

Three cases of LMCAP for the isolated LMCA stenosis were presentd. In two cases of the proximal LMCA stenosis, the connective tissue between the ascending aorta and the main pulmonary artery was prepared to detect the LMCA. From the left lateral wall of the ascending aorta to the anterior wall of the LMCA over the stenotic lesion was excised and the saphenous vein patch was sutured (anterior approach). In the third case, because the stenosis was locarized at the distal LMCA, the patch angioplasty using the saphenous vein was performed by direct opening of the distal LMCA accessed from the left lateral side of the main pulmonary artery without aortotomy (lateral approach). Ultrasonic cuser was quite useful to isolate the LMCA. LA-LV vent was indispensable to obtain the non-blood clean operation field. All three cases showed the successful enlargement of LMCA at the postopeorative coronary angiography.

Our experience with 13 patients (mean age 52, range 35-71 years) undergoing pericardiectomy at Mitsui Memorial Hospital in the 13 years (from 1977 to 1990) has examined with clinical features and M-mode echocardiographic study. Preoperatively, the patients were either in N. Y. H. A. Functional Class III (11 cases), or Class IV (2 cases). Median sternotomy without using cardiopulmonary bypass was employed in all cases. The area of the right ventricle, atria, cavae, pulmonary veins and left ventricle where can be reached without cardiopulmonary bypass or other hemodynamic support were decorticated completely, and the posterior portion of the left ventricle were not decorticated partially. Intraoperative hemodynamic responses were observed between before and after pericardiectomy monitored by Swan-Ganz catheter; central venous pressure (CVP) were changed from 21.3±5.6 to 13.6±4.0cmH₂O, pulmonary artery diastolic pressure (PADP) were changed from 19.8±5.5 to 11.3±6.6mmHg, cardiac index (CI) were changed 2.14±1.34 to 3.16±1.73l/min/m². There were no early deaths and no late heart complicated deaths. There were 2 cases died, one for advanced gastric carcinoma and another for wide cerebral infarction whthin 3 years from pericardiectomy. M-mode echocardiographic study that were examined between preoperative and late postoperative periods (mean follow-up time 51 months) showed effective recovery in cardiac function; left ventricular end-diastolic volume index (LVEDVI) were from 34.3±12.1 to 39.5±14.5ml/m², left ventricular end-systolic volume index (LVESVI) were from 17.2±7.8 to 13.1±6.7ml/m², stroke index (SI) were from 17.1±7.3 to 26.6±12.5ml/m², ejection fraction (EF) were from 45.1±19.2 to 61.2±22.5%, mean velocity of circumferential fiber shortening (mean Vcf) were from 0.80±0.35 to 1.13±0.53circ/sec. All the patients showed functional improvement; 9 are in N. Y. H. A. Functional Class I, and 4 are in Class II. These findings would be permitted this procedure with median sternotomy for chronic constrictive pericarditis as one of a safety and effective method conventionally.

A 24-year-old woman with patent ductus arteriosus underwent division of the ductus. On the fifth postoperative day (POD 5), MRSA was detected in pus from the wound. On POD 8, an emergency operation was performed for left tension hemothorax due to a ruptured aorta with MRSA infection. The bleeding site in the descending aorta was covered with a viable omental flap under deep hypothermic circulatory arrest. Although MRSA was detected in the pleural effusion and the aortic wall, the patient recovered from pyothorax, and pneumonia caused by Pseudomonas aeruginosas and acute renal failure. On POD 37, a pseudoaneurysm of the descending aorta was found and graft replacement was performed on POD 56 due to enlargement of the aneurysm. However, MRSA was not detected in the left pleural effusion. The postoperative course was uneventful. Omental transfer should be considered for the treatment of severe aortic wall infection, even in the presense of MRSA infection.

Injuries to the aorta complicating cardiovascular operations can be very challenging. This type of injury is usually related to manipulation of the aorta during surgical exposure or aortic cannulation. From March 1994 to October 1997, five patients with intraoperative injuries to the thoracic aorta occurred. Their ages ranged from 7 to 71 years old (mean, 43.5 years). Two were male and 3 female. Intraoperatively, trouble occurred suddenly due to acute aortic dissection related to aortic traumatic hemorrhagic disruption in three patients, and aortic cannulation in two patients. The confirmation of the diagnosis was prompted clinically, and all patients immediately underwent further surgical intervention. In terms of technique, we used a cardiopulmonary bypass (mean cardiopulmonary bypass time 239min, range 196 to 367min), and hypothermic circulatory arrest (mean arrest time 34min, range 20 to 44min, at deep hypothermia with 21.0°C urinary bladder temperature) during repair. Retrograde cerebral perfusion was utilized in two cases to assure protection for cerebral damage. Fortunately, there was no postoperative neurological complication and no hospital death in any of the cases. When such intraoperative injuries of the aorta once occur repair using aortic clamps often fail or is not feasible, and in such cases hypothermic circulatory arrest combined with retrograde cerebral perfusion should be applied to resolve this type of the serious troubles.

This study evaluated factors influencing residual aortic regurgitation (AR) after valve re-suspension surgery for acute type A aortic dissection. From January 1996 through December 2002, 63 patients were treated for acute type A dissection at our institution. Among these 63 patients, pre-and postoperative echocardiograms were available in 38 patients who underwent surgery combined with native aortic valve re-suspension. These 38 patients were divided into 2 groups according to the postoperative AR grade, i. e.: AR group: AR grade≥II (n=6), no-AR group: AR grade≤I (n=32). The severity of pre and postoperative AR was assessed by transthoracic or transesophageal echocardiography. The preoperative diameters of mid ascending aorta and sinotubular junction, and the percentage of the circumference of the dissection at the sinotubular junction level was measured by enhanced CT scan. Preoperative patient backgrounds were similar in both groups. The preoperative AR grade in the AR group was significantly greater than that of the no-AR group (2.25±1.17: 0.69±0.91, p<0.001). The tear was more frequently located in the ascending aorta in the AR group than in the no-AR group (66.7%: 37.5%, p<0.05). The percentage of circumference of the dissection at the sinotubular junction level did not affect the preoperative AR grade, but it did show a tendency to influence the severity of postoperative AR, though the difference was not significant. Three patients (7.9%) had AR grade III at the time of discharge, but did not clinically require further surgical intervention. Preoperative significant AR and the location of the tear in the ascending aorta are associated with postoperative residual AR after aortic valve re-suspension. The percentage of circumference of the dissection at the sinotubular junction level might influence the severity of postoperative AR.