[Off-pump coronary artery bypass surgery for the ischemic cardiomyopathy patient with moderate mitral regurgitation and stenosis of bilateral vertebral arteries]

We report a 71-year-old man who had severe coronary and cerebral vascular disease with moderate mitral regurgitation (MR). Left ventricular reconstruction and mitral valve surgery were considered for poor left ventricular function and dilatation with MR. However, low blood pressure during cardiac arrest was risk for stroke due to severe stenosis of bilateral vertebral arteries. The myocardial viability of the anterior wall and inferior wall was confirmed by thallium-201 rest-redistribution single photon emission computed tomography (SPECT). Therefore, off-pump coronary artery bypass grafting (OPCAB) was selected for the patient. Only three Lima sutures were used for keeping the optimal heart position. Coronary anastomoses were done in sequence right gastroepiploic artery (RGEA)-#4 posterior descending (PD), left internal thoracic artery (LITA)-#9-#14 (sequential), RITA-#8 left anterior descending (LAD). No neurological complication occurred postoperatively. Left ventricular function and MR gradually improved. Final ejection fraction (EF) is 51% and MR is trivial. This case demonstrated improvement of MR by only revascularization according to preoperative viability assessment.

[Successful mitral valve plasty in a 6-month-old baby suffering from severe mitral valve regurgitation]

A 6-month-old male infant was referred to our hospital with diagnosis of severe left heart failure stemming from severe mitral valve regurgitation (MR). He showed severe decompensation, and emergency operation was performed. Intraoperative transesophageal echocardiogram showed ruptured chordae of the posterior leaflet at P1 and P3 sites. The both sites of the posterior leaflet were resected and sutured. Bilateral Kay annuloplasty and partial annuloplasty at the sites of P1 and P3 were also performed. Postoperative echocardiogram showed only trivial MR. He made successful recovery after surgery.

[Pulmonary pleomorphic carcinoma; an investigation of thirteen cases]

Pleomorphic carcinoma is a rare pulmonary epithelial malignant tumor defined in the World Health Organization classification updated in 1999. We investigated the clinical findings and prognosis associated with this tumor since to our knowledge they have yet to be well-understood. Between 2000 and 2006, in our hospital 387 patients underwent surgical resection for primary nonsmall cell lung carcinoma (NSCLC). Of these, 13 (3.4%) were diagnosed as pleomorphic carcinoma. We compared the clinical and pathological data between the patients with pleomorphic carcinoma (n = 13) and patients with other NSCLC (n = 374). Twelve (92.3%) of our patients were men and 9 (69.2%) were symptomatic. These tumors were located predominantly in an upper lobe and were associated more often with adjacent bullae than were other NSCLC. Surgical resection in 4 of the cases was incomplete due to tumor invasion into mediastinum, aortic arch, pleurae and/or chest wall. None of the diagnoses could be confirmed preoperatively. Thus, invasion of surrounding tissue occurred frequently and early. Although there are no defined management strategies for pleomorphic carcinoma, it is important to make the diagnosis early and perform complete resection if possible.

Haemostatic Fleece (TachoComb®) to Prevent Intrapleural Adhesions after Thoracotomy: A Rat Model

BACKGROUND

Postoperative adhesion is a complication common to all surgical subspecialties. TachoComb is a collagen fleece with properties well suited to the prevention of adhesion. This preclinical study was performed to evaluate the efficacy and mechanism of action of TachoComb in the prevention of adhesion following pleural injury during thoracic surgery.

METHODS

Rats (n = 72) were randomised to receive saline or TachoComb following pleural injury. The macroscopic severity of adhesion formation and histological changes were assessed following euthanasia at time points up to 28 weeks post-operation. Levels of the biochemical markers t-PA, PAI-1 and bFGF were measured in intrapleural lavage fluid.

RESULTS

The severity of adhesion was lower in TachoComb-treated animals compared with control animals at all time points (mean adhesion score: 1.4 vs. 4 at week 28 post-operation; P < 0.01). Regeneration of the mesothelial cell stratum occurred faster in TachoComb-treated animals, and a significantly lower PAI-1 activity was observed (14.32 vs. 23.28 U/ml; P < 0.01).

CONCLUSIONS

TachoComb is effective in the prevention of adhesion following thoracic surgery, both by acting as a physical barrier and by inhibiting PAI-1 activity.

[Off-pump coronary artery bypass in high-risk patients]

In this study, 110 consecutive patients who had undergone off-pump coronary artery bypass (OPCAB) in the past 2 years were evaluated for early results of OPCAB. Patients were classified as a high-risk group (H group: 68 patients consisting of 46 men and 22 women) and a low-risk group (L group: 42 patients consisting of 31 men and 11 women), respectively, and were evaluated for the early operative results. No differences were noted between the H and L groups in the mean number of bypass grafts (2.9 +/- 0.9 in the H group, 2.9 +/- 0.9 in the L group), the rates of complete revascularization (85% in the H group, 93% in the L group), those of various graft materials bypassed, or those of sequential bypass. In all patients, we were able to undergo coronary revascularization by the aortic no-touch technique using arterial grafts exclusively. In the H group, 1 patient (1.5%) died in hospital, but no patients developed cerebral infarction postoperatively, and the frequency of complications was similar to that in the L group. The results of OPCAB for high-risk patients were good, and it was suggested that OPCAB using in situ arterial grafts was very useful particularly in patients with cerebrovascular diseases.

[Aortic valve replacement for calcified aortic valve and annulus with ultrasonic decalcification]

We conducted ultrasonic decalcification on calcified annulus in patients with aortic stenosis (AS) using an ultrasonic operator, Sonopet (UST 2001) prior to aortic valve replacement (AVR). We studied the reliability of this method.

SUBJECT AND METHOD

From January 2002 to August 2005, AVR was conducted for AS using the Sonopet in 45 patients, comprising of 18 male and 27 female subjects. The mean age was 73.3 +/- 9.7.

RESULT

Artificial valves were successfully inserted at the intra-annular level in 37 patients and at the supra-annular level in 8 patients without conducting annular enlargement. In the patients with narrow annuli of less than 19 mm (23 patients), the preoperative mean annular diameter was 18.2 +/- 1.0 mm, but significantly larger artificial valves with an average diameter of 19.3 +/- 1.5 mm (p=0.003) were successfully inserted.

CONCLUSION

AVR was proved to be safe and easy by previous ultrasonic decalcification of the annuls using the Sonopet. This method was very useful because it required no enlargement of aortic annulus.

Surgical correction of pseudoaneurysm of the extracranial carotid artery: the usefulness of retrograde cerebral perfusion--a case report

Although a pseudoaneurysm of the common carotid artery is not encountered frequently, its surgical treatment is technically challenging. A case is reported of a large pseudoaneurysm of the right common carotid artery in a 45-year-old woman, presenting with respiratory distress, following a wound infection 3 months after tracheoplasty. Instead of a vascular shunt, deep hypothermic circulatory arrest with retrograde cerebral perfusion was used for protection of the brain against hypoxia during the arterial reconstruction. The pseudoaneurysm was easily corrected with an autologous saphenous vein, without any hazardous dissection through the dense fibrosis around the fragile pseudoaneurysm, under circulatory arrest.

[Subependymoma of the lateral ventricle: a case report]

We report a case of subependymoma of the right lateral ventricle in a 59-year-old man. CT revealed a mass lesion in the right lateral ventricle. No calcification was seen in the tumor, and the right lateral ventricle was dilated dominantly by the tumor. The tumor showed intermediate intensity on T1-weighted MR images and high intensity on T2-weighted MR images. On contrast study, the tumor showed heterogeneous enhancement. We suspected this to be a case of central neurocytoma, and surgical resection was performed. The histological diagnosis was subependymoma, but we considered it difficult to differentiate from astrocytoma, central neurocytoma, and ependymoma.

Influence of static pressure and shear rate on hemolysis of red blood cells

The purpose of this study was to investigate the effect of multiple mechanical forces in hemolysis. Specific attention is focused on the effects of shear and pressure. An experimental apparatus consisting of a rotational viscometer, compression chamber, and heat exchanger was prepared to apply multiple mechanical forces to a blood sample. The rotational viscometer, in which bovine blood was subjected to shear rates of 0, 500, 1,000, and 1,500 s(-1), was set in the compression chamber and pressurized with an air compressor at 0, 200, 400, and 600 mm Hg. The blood temperature was maintained at 21 degrees C and 28 degrees C. Free hemoglobin at 600 mm Hg was observed to be approximately four times higher than at 0 mm Hg for a shear rate of 1,500 s(-1) (p < 0.05). The results suggest that the increase in hemolysis is strongly related to pressure when high shear rates are applied to the erythrocytes. The data acquired in this study will be helpful in the development of artificial organs, where it will facilitate the prediction of hemolysis in flow dynamics analysis, flow visualization, and computational fluid dynamics.

Early results of coronary grafting using ultrasonically skeletonized internal thoracic arteries

BACKGROUND

We have developed an ultrasonic complete skeletonization technique for obtaining internal thoracic artery (ITA) grafts and have used this method clinically since January 1998. In this report, we discuss the early results of bilateral ITA grafts obtained with our method.

METHODS

We studied 200 consecutive patients who underwent coronary artery bypass grafting using ITAs obtained by this technique. Angiography of the grafts was performed in 188 patients (94%) within 1 month after coronary artery bypass grafting.

RESULTS

The ITA grafts were about 4 cm longer than pedicled ITA grafts. The free flow through the grafts was at least 30% higher than through pedicled ITAs. The early patency rate determined by postoperative angiography of the grafts was 99.7% for left ITAs and 100% for right ITAs. No patient required postoperative intervention or repeated surgery.

CONCLUSIONS

Ultrasonic complete skeletonization increases the effective length of ITA bypasses, improves free flow through the bypasses, and it is less invasive than conventional pedicled harvesting. These excellent early results indicate that this technique is a straightforward, safe, less invasive, and optimal method for obtaining ITA bypass grafts.

Histologic and physiologic evaluation of skeletonized internal thoracic artery harvesting with an ultrasonic scalpel

OBJECTIVES

The safety and reliability of a method of skeletonized internal thoracic artery harvesting with an ultrasonic scalpel (Harmonic Scalpel; Ethicon Endo-Surgery, CVG, Cincinnati, Ohio) were evaluated.

METHODS

The mural branches of the internal thoracic artery were cut by means of 3 methods, differentiated by distance from the site of application of the Harmonic Scalpel blade to the internal thoracic artery. A total of 15 branches were cut from the internal thoracic artery at (0 mm) the origin (group I) or at 1 mm (group II) or 2 mm (group III) distal to the origin. Tissue preparations were examined for successful vessel closure and severity of tissue damage. The length of stump (L) and the length of tissue damage from the stump (D) were determined by a computer image analysis system, and pressure testing was performed to evaluate the physical strength of vessel closure.

RESULTS

In group I, 8 of the 15 branches exhibited discontinuity of the vascular wall structure, probably because of insufficient sealing of the divided section, and 12 of the 15 branches exhibited tissue denaturation on the internal thoracic artery wall adjacent to areas of origin, which was probably caused by the heat transferred from the branches during the process of coagulation. In groups II and III, continuity of wall structure of stumps suggestive of stable closure of branches was confirmed. The lengths of tissue damage from the stump (D) were 0.96, 0.58, and 0.63 mm in groups I, II, and III, respectively, and the lengths of intact area (L - D) in the corresponding groups were -0.78, 0.61, and 1.51 mm. The negative figure in group I indicates the presence of tissue damage in the internal thoracic artery itself. By contrast, in groups II and III the internal thoracic arteries were intact, with a safety margin of greater than 0.5 mm. On physiologic evaluation of vessel closure, 2 of the 24 (8.3%) branches burst under a pressure lower than 350 mm Hg because of insufficient vessel coagulation, but the remaining 22 branches (91.7%) remained intact under pressures up to 350 mm Hg.

CONCLUSION

The internal thoracic artery skeletonization method with an ultrasonic scalpel (Harmonic Scalpel: output level 2) appears to be a safe and reliable method of skeletonized internal thoracic artery harvesting when branches are sectioned at least 1 mm distal to their origin at a sufficiently slow speed.

An investigation of blood flow behavior and hemolysis in artificial organs

In our previous study, in vitro hemolysis tests showed that collision flow against wall roughness had an effect on hemolysis when the flow velocity was more than 3 m/s and surface roughness was more than Ra = 1.54 microm. However, the specific portion of the flow on the wall that induced hemolysis was not clarified. Therefore, the purpose of this study was to present the relationship between flow behavior and hemolysis by means of in vitro tests and computational fluid dynamics (CFD) analysis. We investigated the relationship between the location of surface roughness and hemolysis. In CFD, we investigated the flow behavior on the wall. The highest rate of hemolysis was observed in a region around the center of the surface roughness on the bottom plate. On CFD analyses, the flow behavior included the highest wall shear stress (304 Pa) and the highest flow acceleration (2.8 m/s2) around the center of the bottom plate. Therefore, it is concluded that the causes of hemolysis during collision flow depend upon wall shear stress and flow acceleration.

[Management of coronary artery disease combined with aortic stenosis: how to do with mild aortic stenosis]

A total of fourteen patients with combined operation of coronary artery bypass grafting (CABG) and aortic valve replacement (AVR) for coronary artery disease (CAD) and aortic stenosis (AS) were reviewed to evaluate the indication of the combined operation. Preoperative pressure gradient across the valve and effective orifice area were 21-89 mmHg (mean 64 mmHg), 0.5-1.9 cm2 (mean 0.92 cm2), respectively. The extent of CAD was 1-3 (mean 2.0). Fractional shortening (%FS) ranged from 13% to 43% with mean value of 28%. All patients underwent CABG and AVR. The number of grafts was 1-4 (mean 2.3) with internal thoracic artery used in 7 cases. Mechanical valves were employed for all patients except 1 case with cerebral aneurysm. There was no operative death, although low output syndrome developed in 2 cases. One had poor left ventricular function preoperatively, and the other was emergency case. Fractional shortening improved postoperatively even in two cases with preoperative %FS less than 20%, and all grafts were patent on postoperative coronary angiography. The event-free survival was 100% during 32 months of mean follow-up. Combined AVR with CABG is recommended to avoid risky secondary operation in patients of CAD and AS, even if one of which is relatively mild, because of the fact that operative and late results of the combined surgery are satisfactory.

Skeletonization and harvest of the internal thoracic artery with an ultrasonic scalpel

A new method to skeletonize and harvest the internal thoracic artery using an ultrasonic scalpel is presented. The technique is simple, safe, and minimally invasive. It is possible to obtain sufficient vessel length for anastomosis to most coronary arteries for bypass grafting.

Coronary artery bypass grafting using the "Super Pulse" dynamic pulsatile cardiopulmonary bypass device in patients with cerebrovascular occlusive disease

Patients with coronary disease complicated by severe carotid or intracranial arterial stenosis underwent coronary artery bypass graft surgery (CABG) using a novel method of dynamic pulsatile cardiopulmonary bypass (Super Pulse CPB). The Super Pulse technique can maintain the systolic pressure and systolic-diastolic amplitude in such a way that they mimic the physiologic circulation. Forty-five patients (33 males and 12 females, mean age 65.1 years) with coronary disease who had a greater than 75% stenosis of the carotid or intracranial arteries were evaluated. Evaluation was performed for the following 3 groups: 8 patients with conventional pulsatile CPB (Group I), 8 patients with conventional pulsatile CPB plus intraaortic balloon pumping (Group II), and 29 patients with Super Pulse CPB. Maximum, minimum, and mean perfusion pressures during CPB were 112.7, 53.6, and 76.9 mmHg (integrated mean), respectively, in Group III. The systolic-diastolic amplitude was significantly better than for Group I and similar to baseline pressures. No patients in Group II or Group III developed perioperative cerebral disorders or myocardial infarction, while in Group I perioperative cerebral disorders developed in 3 patients, myocardial infarction occurred in 2 patients, and 2 patients died during hospitalization. The initial performance of the Super Pulse CPB indicates excellent safety, and is useful for patients with co-morbid cerebral arterial disease.

Minimally invasive direct coronary artery bypass grafting using the gastroepiploic artery for reoperation after the Cabrol procedure

Obstruction of the right coronary ostial anastomosis is a rare late complication after composite graft replacement of the ascending aorta and the aortic valve with separate Dacron coronary grafts (Cabrol method). Occlusion at the right coronary ostial anastomosis in a 36-year-old woman with aortitis syndrome who underwent a composite graft with a Dacron coronary graft is described. She underwent a third successful operation for right coronary reconstruction by minimally invasive direct coronary artery bypass grafting technique using the right gastroepiploic artery. This approach is likely to be extremely useful in avoiding resternotomy and cardiopulmonary bypass in patients requiring coronary reoperation.

Two cases of aorto-gastrointestinal fistula

We report two cases of aorto-gastrointestinal fistula. Case 1, a 60-year-old man, suffered from repeat hematemesis. He was preoperatively diagnosed as aortoesophageal fistula with thoracic aortic aneurysm and was successfully treated by graft replacement of the aneurysm. Case 2, a 73-year-old man, presented with massive gastrointestinal bleeding, yet repeat endoscopical examination did not reveal the origin of the bleeding. He died of catastrophic hematochezia. The pathological findings at autopsy revealed an aortoduodenal fistula. These two cases suggested the importance to consider an aorto-gastrointestinal fistula in the differential diagnosis of patients presenting gastrointestinal hemorrhage.

Retrograde cerebral perfusion versus selective cerebral perfusion as evaluated by cerebral oxygen saturation during aortic arch reconstruction

BACKGROUND

Time limits for neuroprotection by retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP) in aortic arch aneurysm repair or dissection are undergoing definition.

METHODS

Using near-infrared optical spectroscopy, changes in regional cerebrovascular oxygen saturation (rSO2) were compared between the two perfusion methods.

RESULTS

Immediately before cardiopulmonary bypass, baseline rSO2 was 63.9%+/-6.9% for the RCP and 66.1%+/-5.3% for the SCP group (no significant difference). As patients were core-cooled to 20 degrees C, rSO2 increased to 73.1%+/-8.8% and 74.1%+/-7.9% in the RCP and SCP groups, respectively. With circulatory arrest, rSO2 suddenly decreased. After starting cerebral perfusion, rSO2 returned to prearrest values in the SCP group but continued decreasing steadily in the RCP group, to levels below baseline after about 25 minutes. At the end of perfusion, rSO2 was 57.4%+/-12.2% for the RCP group and 71.7%+/-6.9% for the SCP group, and the ratio of rSO2 to baseline value was 0.89 for RCP and 1.08 for SCP despite a shorter brain perfusion time for RCP (38.8+/-18.0 versus 103.3+/-43.3 minutes). Three of 5 patients whose ratios of rSO2 to baseline at the end of brain protection were 0.7 or less had neurologic deficits.

CONCLUSIONS

Although SCP showed no clinically important time limitation, rSO2 continued to decrease with time during RCP. An rSO2 ratio less than 0.7 could represent a critical lower limit.

[Elimination of artifacts in MRCP: technical consideration]

Artifacts of MR cholangiopancreatography (MRCP) include fluid-filled gastrointestinal tracts, respiratory motion artifacts, spasm of Oddi's sphincter, vascular compression of bile ducts, overlapping of various anatomical structures and bright signal of surrounding fatty tissue. In this article, various technical considerations to eliminate these artifacts were described for the better imaging analysis of MRCP. The use of high-concentration ferric ammonium citrate (Ferriseltz) is recommended to reduce bright signal of fluid-filled gastrointestinal tracts. In case of long breathhold sequences, O2-inhalation study is useful to eliminate respiratory motion artifacts. Careful attention should be paid to the spasm of Oddi's sphincter and the vascular compression of bile ducts to avoid erroneous interpretation of MRCP findings.

Emergency percutaneous cardiopulmonary bypass support for acute myocardial infarction

We assessed the efficacy of emergency percutaneous cardiopulmonary bypass support (PCPS) in the treatment of patients with acute myocardial infarction complicated by cardiogenic shock. Emergency PCPS was instituted in 21 consecutive patients beginning in 1991. After the stabilization of the hemodynamics, coronary reperfusion was performed by means of coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. Of the seven patients with acute myocardial infarction involving either the left main or two-vessel territories, five survived more than 1 month, but only one patient remained alive and well after 20 months. The main cause of death for this group was low output syndrome. Four of 12 patients with acute left main trunkal occlusion in the catheter laboratory survived and showed a preserved cardiac function (mean followup 28.5 months). The main cause of death for this group was brain damage. Two patients with single-vessel territory acute myocardial infarction underwent PCPS to treat refractory ventricular fibrillation. Both patients were still alive and well at a 12-month followup. Percutaneous cardiopulmonary bypass support successfully stabilized the hemodynamics, allowing time to perform revascularization for all three groups of patients with life-threatening acute myocardial infarction. Recanalization was nevertheless unable to salvage the damaged myocardium in cases of prolonged ischemic time.

[Rupture of the papillary muscle after percutaneous transvenous mitral commissurotomy (PTMC)--a case report]

We experienced a rare case of the mitral regurgitation due to papillary muscle rupture after percutaneous transvenous mitral commissurotomy (PTMC). This case was a seventy years old female who underwent PTMC. The cardiac tamponade and mitral regurgitation occurred after PTMC. Pericardial drainage was done immediately, and the next day the emergency operation was required. Rupture of the posterior papillary muscle was found at the operation, and mitral valve replacement was performed. Her postoperative course was uneventful and she discharged on the 26th day after the operation. We should take the papillary muscle rupture into consideration if there are severe sub-valvular lesion and shorting of the chorda.

Leriche syndrome. Surgical procedures and early and late results

During the past thirteen years, 29 patients underwent surgical intervention for Leriche syndrome. Fifteen patients (aged forty-two to seventy-two years, average 60.7 years) underwent anatomical bypass, and 9 of them whose thrombus was confined to the infrarenal aorta received a routine graft insertion. In the other 6 whose thrombus extended to the level of the renal arteries, an open thrombectomy of the juxtarenal aorta was first performed through a transection of the infrarenal aorta under renal ischemia (4-14 minutes, average 7). Twelve elderly or high-risk patients (aged sixty-eight to eighty-four years, average 75.3 years) underwent an axillobifemoral bypass, and another 2 (fifty-eight and sixty years old, respectively) who had been operated on at an earlier time received an ascending aortobifemoral bypass. In cases of anatomical bypass, no graft has occluded and all patients but 1, who died of cerebral infarction, have an active life now. In cases of extraanatomical bypass, 5 of the 28 grafts occluded and only 6 patients have survived. The other 8 patients died of malignancy, atherosclerotic complications, or unknown causes. The 10-year survival rate was 92.9% and 29.5% in the anatomical bypass and extraanatomical bypass group, respectively. In Leriche syndrome, anatomical bypass is preferred to extraanatomical bypass if conditions permit. In the juxtarenal type, an open thrombectomy under renal ischemia is mandatory for anatomical bypass, and a transection of the infrarenal aorta facilitates this procedure. Because the patients with Leriche syndrome are elderly and harbor arteriosclerotic lesions, a careful follow-up is mandatory.

Development of a membrane oxygenator for ECMO using a novel fine silicone hollow fiber

One of the limitations of conventional silicone hollow fiber oxygenators compared with microporous membrane oxygenators is poor gas permeability. However, the silicone hollow fiber is free from plasma leakage, which is the major life limiting factor of the microporous membrane oxygenator. It has been difficult to fabricate a fine, thin hollow fiber for reduction of resistance to gas permeability because of the poor mechanical strength of conventional silicone materials. The authors developed a novel silicone material with sufficient mechanical strength, and a fine silicone hollow fiber with a diameter of 30 microns and wall thickness of 50 microns, which is approximately half that of a conventional silicone hollow fiber. Using this newly developed silicone hollow fiber, the authors developed a compact extracapillary flow membrane oxygenator. The oxygenator consists of fine silicone hollow fibers inserted in a housing made of polycarbonate. The housing is a cylindrical case, 20 cm long and 55 mm in inside diameter. The hollow fibers are cross-wound. The surface area of the membrane is 2.0 m2, and priming volume is 230 ml. Gas transfer performance of the newly developed oxygenator was evaluated by in vitro experiments. Oxygen and carbon dioxide transfer rates were 195 ml/min and 165 ml/min, at a blood flow rate 3 L/min. The novel silicone membrane oxygenator developed in this study can be used for extended duration in such applications as extracorporeal membrane oxygenation.

Surgical treatment of infective endocarditis complicated by annular infection and cerebral infarction

The surgical treatment of nine patients with infective endocarditis (IE) complicated by annular infection and five with IE complicated by cerebral infarction is described herein. In those with annular infection, after thorough débridement of the infected tissues, valve replacement was performed at the original position in five, at the supraannular position in three, and one underwent a translocation procedure. Aortic valve replacement was able to be performed at the original position in two patients by closing the defect at the aortic annulus with a patch after through débridement. The five patients who underwent original valve position replacement recovered well. Of the three who underwent supraannular position replacement, two died of septicemia after a redo operation, and one received pacemaker implantation. The patient undergoing the translocation procedure died of intestinal infarction. In the five patients who suffered cerebral infarction due to embolus of the vegetation, valve replacement was performed between 40 h and 5 months after its onset. Although one patient died of the rapid progression of brain damage, the other four are alive and well, including two who developed mycotic cerebral aneurysm in the infarcted areas. In conclusion, early surgery for IE is mandatory irrespective of active infection, due to the high mortality and morbidity associated with serious sequelae such as annular abscess or cerebral infarction.

Pericardiectomy and coronary artery bypass grafting for constrictive pericarditis after heart surgery

A 63-year-old male was operated on for chronic heart failure due to myocardial ischemia and constrictive pericarditis after heart surgery. He was in New York Heart Association (NYHA) class III under a large dose of diuretics. He underwent a pericardiectomy and coronary bypass surgery without cardiopulmonary bypass. His cardiac function improved with a patent graft. He is now, 1 year after surgery, in NYHA class I under a tapering dose of diuretics.

Surgical treatment of ventricular septal perforation with right ventricular infarction

A 71-year-old woman underwent an emergency surgery for ventricular septal perforation together with right ventricular infarction. The perforation of the anterior septum was closed using. Dacron patch combined with a little larger bovine pericardium, the surplus of which was stitched in the surrounding viable muscle. This procedure was performed only through the infarct of the right ventricle. She has been doing well with no residual shunt and lives a normal life now.

[Graft replacement of a thoracic aneurysm and coronary artery bypass grafting using retrograde cerebral perfusion through left thoracotomy--a case report]

A 67-year-old woman having descending thoracic aneurysm and 90% stenosis of the obtuse marginal artery underwent a concomitant operation of graft replacement of a thoracic aneurysm and coronary artery bypass grafting. The operation was performed through left posterolateral thoracotomy with total cardiopulmonary bypass using femoral artery, femoral vein and the pulmonary artery cannulation, deep hypothermia and retrograde cerebral perfusion (RGCP). RGCP was performed by high central venous pressure (17-18 mmHg) resulted from low flow perfusion of the lower body under clamping of the descending aorta. Distal coronary anastomosis was done during an initial 100ling period and proximal anastomosis was put on the replaced thoracic graft after coming off extracorporeal circulation (ECC). ECC time was 167 minutes, and RGCP time was 27 minutes. The patient did well after the operation. Postoperative coronary angiography showed the patent coronary bypass graft. We conclude that this method provides good exposure of the thoracic aorta and the coronary artery, and satisfactory brain protection.

[A comparison of changes of cerebrovascular oxygen saturation in retrograde and selective cerebral perfusion during aortic arch surgery]

To evaluate the effect of retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP) on brain protection, changes of cerebrovascular oxygen saturation (rSO2) were studied in 14 patients with aortic arch reconstruction during the procedure. The rSO2 was monitored with spectroscopy instrument (Invos 3100, Somanetics). The mean value of rSO2 measured just before cardiopulmonary bypass was 65.9 +/- 6.2% in 7 patients with RCP, and was 64.9 +/- 4.7% in 7 patients with SCP. The value of rSO2 during core cooling of cardiopulmonary bypass was increased step by step. Although RCP time with a mean of 38.9 +/- 9.7 min was statistically shorter than SCP time (80.7 +/- 45.1 min), the mean value of rSO2 during cerebral protection in RCP group was decreased from 80.3 +/- 8.1% to 63.4 +/- 10.2%, lowest 46% with a ratio of 21.1%. In contrast, the mean value of rSO2 in SCP group was well maintained from 79.9 +/- 6.5 to 75.6 +/- 6.8%, lowest 63% with a ratio of 5.4%. Although no neurological deficits were recognized after operation in both groups, rSO2 in SCP group was sustained above the control value (65% just before cardiopulmonary bypass) but rSO2 in RCP group was decreased below the control value after 35 min. So we conclude that with regard to brain protection assessed from rSO2 measured by Invos 3100 cerebral oximeter, there is no time limitation of SCP during the procedure but RCP had a limit of the duration.

[A case of type A acute aortic dissection successfully treated with a ringed intraluminal graft: a new technique of graft insertion]

A-77-year old woman was hospitalized at our hospital presenting with severe chest and back pain. A computed tomographic scan revealed acute type A aortic dissection and intraoperative ultrasound showed an entry near the brachiocephalic artery. Selective cerebral perfusion using flexible 12 Fr balloons was performed for brain protection. The distal aorta was trimmed just proximal to the entry using felt strips and a 24 mm ringed intraluminal graft (ILG) was inserted under it successfully. The patient did well after the operation. Insertion of a ringed ILG is a simple and easy technique, however if an entry is located near the aortic arch, insertion is difficult because of intimal retraction to the arch. And an additional intimal tear sometimes occurs at the site of tape ligation. The method which we presented seemed to provide safer insertion of the proximal ring without these problems.

[Mitral valve repair for the treatment of ischemic mitral regurgitation]

Twenty-six patients with moderate and severe ischemic mitral regurgitation due to papillary muscle dysfunction underwent mitral valve replacement (MVR) or mitral annuloplasty (MAP) using modified Kay method. Emergent operation was performed in 12 patients of whom 11 had severe congestive heart failure even under IABP, 5 had cardiogenic shock and 9 needed respiratory care with intubation preoperatively. Elective operation was performed in 14 patients of whom 6 had history of congestive heart failure and 1 had episodes of ventricular tachycardia. As intraoperative findings of mitral valve, mural annular dilatation in 84.6%, prolapse of anterior leaflet in 23.1%, papillary muscle scar in 15.4%, chordal elongation in 15.4% and chordal rupture in 3.8% were seen separately or in combination. In 22 patients MAP using modified Kay method and CABG were performed, but in 4 patients MVR was needed because of the prominent prolapse of the anterior leaflet. Fourteen patients who underwent MAP with CABG and one MVR with CABG survived. Hospital mortality was higher in emergent (58.5%) than elective operation (28.6%). In the 15 survivors, mitral regurgitation decreased below Sellers 2, pulmonary wedge pressure decreased significantly (p < 0.01) and NYHA functional class improved to I or II postoperatively. During the follow up period of 15-100 (mean 38.7 +/- 21.6) months, 2 MAP+CABG patients died suddenly, but the remaining 13 patients were in NYHA class I or II and no progression of MR was seen. These results indicated that MAP+CABG is recommendable in the treatment of ischemic mitral regurgitation due to papillary muscle dysfunction, in order to preserve cardiac function and to reduce valve related complications.

Mitral valve repair using an annuloplasty ring made of artificial woven Dacron graft

A woven Dacron ring made of artificial graft was successfully used in combination with a modified Kay's annuloplasty for mitral valve repair. In this procedure, after excision and repair of the redundant prolapsed leaflets, Kay's annuloplasty was performed at both commissures to reduce the posterior annulus and to coapt the leaflets. A woven Dacron ring was then seated and tied to the annulus to provide long-term stabilization and prevent its further dilatation. The mitral orifice of the patient was reduced from 33 mm to 21 mm in diameter, and neither mitral regurgitation nor stenosis was found in the postoperative evaluation.

[Efficacy of terminal warm blood cardioplegia against the reperfusion injury]

The effect of terminal warm blood cardioplegia (TWBC) was evaluated from the incidence of ventricular fibrillation and myocardial metabolism after release of aortic clamping in 70 patients (group I) who underwent open heart surgery using TWBC compared with 70 patients (group II) without TWBC. The incidence of ventricular fibrillation after unclamping in group I was 19.7% which was statistically less than 68.6% in group II. Both excess lactate (delta XL) and redox potential (delta Eh) demonstrated that anearobic myocardial metabolism after reperfusion was restored more rapidly in group I than in group II. Multivariate analysis showed the incidence of ventricular fibrillation after reperfusion was related to high concentrations of both calcium and sodium and low concentration of potassium in reperfused blood in group II. But it was only related to left ventricular myocardial temperature in group I. High concentration of calcium and low concentration of potassium in reperfused blood, and low myocardial temperature were most related to anearobic metabolism of myocardium following reperfusion in group II, whereas only pH value was closely related to recovery for myocardial metabolism in group I. In conclusion, TWBC was useful for improving microcirculation in myocardium and avoiding calcium-overload to myocardial cells, and resulted in reducing reperfusion injury in myocardium. Furthermore, acid content of TWBC and enough amount to raise myocardial temperature would provide more efficacy on myocardial preservation.

Surgical treatment of ventricular septal defect and its sequelae in adults

We operated on 20 adult patients with ventricular septal defect (VSD). In 7 of these cases (aged 36 to 51 years, average 42.6 years), VSD was accompanied by sequelae other than pulmonary hypertension. Concomitant procedures in type-I VSD included a suspension of the prolapsed aortic cusp in 2 patients, a repair of the ruptured sinus of Valsalva in 2, and a new procedure for active infective endocarditis, described below, in 2. In this latter procedure, the aortic valve and infected Valsalva sinus were excised, and the pulmonary valve and the right ventricular wall to which the infection had extended were thoroughly debrided. The resulting defect was closed with a single patch, and a prosthetic valve was inserted in the position of the original aortic valve using this patch as part of the annulus. Another patient with the type-II VSD underwent concomitant tricuspid valve replacement for infective endocarditis. In the mean follow-up period of 77.1 months, 6 patients have been doing well in New York Heart Association class I, and the remaining patient with Valsalva repair remained in class II due to dilated cardiomyopathy.

The problems of surgical treatment for cardiac myxoma and associated lesions

Twenty-four patients with cardiac myxomas consisting of 22 left and 2 right atrial myxomas were operated on. All myxomas were removed with an excision of the attachment walls using a cardiopulmonary bypass. Two myxomas required a partial cardiopulmonary bypass from the femoral vein to the artery prior to operation because they were on the verge of becoming stuck in the atrioventricular valves and potentially causing shock. For embolic complications of myxoma, the embolus of the external carotid artery was extirpated before undergoing cardiac surgery. In a patient with pulmonary infarction, the infarcted lung was resected simultaneously. Another patient with a cerebral infarction received a clipping of an aneurysm which later appeared in the infarcted area. For associated cardiac lesions, two patients underwent a coronary artery bypass graft and one mitral valve replacement with tricuspid annuloplasty. In the former two cases, the myxoma was removed prior to coronary artery bypass grafting because the use of retrograde coronary perfusion was considered to be sufficient to protect the heart. In the latter case, the removal of the myxoma first disclosed a significant mitral lesion which had been masked by the huge myxoma. All patients but one, who died of pneumonia, showed a good recovery. In this series, the problems of surgical treatment for cardiac myxoma and associated lesions are also discussed.

Surgical treatment of ventricular septal defect and ruptured sinus of Valsalva associated with infective endocarditis

Two patients with ventricular septal defect of Kirklin type I and ruptured right coronary sinus of Valsalva associated with infective endocarditis were operated on. Both had bacillus vegetation clinging to the aortic and pulmonary valves and the right ventricular intimal wall around the septal defect. Aortic and pulmonary regurgitation were also found. The surgical approach included vertical incision of the right ventricular outflow tract and pulmonary trunk and transverse aortotomy. The right coronary sinus of Valsalva showed distinct aneurysmal change in one patient. The aortic valve and infected Valsalva sinus were excised in both cases, and the pulmonary valve and right ventricular wall where infection extended thoroughly débrided. The resulting defect, including the ventricular septal defect and excised right Valsalva sinus and aortic annulus, was closed with one patch, and the prosthetic valve inserted in the position of the original aortic valve using this patch as part of the annulus. Both patients had a good postoperative course and are doing well, although slight pulmonary regurgitation persists.

[Mitral valve replacement and right ventricular outflow repair for hypertrophic obstructive cardiomyopathy]

A 44-year-old male with hypertrophic obstructive cardiomyopathy (HOCM) was operated on. He was in NYHA class III with a chief complaint of exertional dyspnea refractory to medical treatment. Echocardiography showed asymmetric septal hypertrophy and systolic anterior movement of the mitral valve, which caused obstruction of the left ventricular outflow tract. It also showed obstruction of the right ventricular outflow tract due to septal hypertrophy. Cardiac catheterization showed a systolic pressure gradient of 70 mmHg at the LV outflow tract and that of 30 mmHg at the RV outflow tract. He underwent mitral valve replacement and patch enlargement of the RV outflow tract. Postoperative course was uneventful. Postoperative catheterization showed a remarkable decrease of pressure gradient to 10 mmHg at the both outflow tracts.

The efficacy of non-clamping selective cerebral perfusion in distal aortic arch aneurysm repair: report of a case

Successful repair of a distal aortic arch aneurysm without aortic cross-clamping was carried out in a 74-year-old man, using a combination of special separate cerebral perfusion and retrograde coronary perfusion, termed non-clamping selective cerebral perfusion. We believe that satisfactory results following aortic arch surgery in elderly patients can only be achieved through the prevention of emboli derived from an aortic cross-clamping site, and shortened ischemic time of the vital organs.

[Change of mitral regurgitation before and after myocardial revascularization--is mitral repair required for ischemic mitral regurgitation?]

In twenty seven patients, intraoperative change of ischemic mitral regurgitation before and after coronary artery bypass grafting (CABG) was assessed using transesophageal echocardiography. The size of mitral regurgitation (MR) was determined by the area of MR color flow on the doppler echocardiogram. After CABG, MR area decreased in 20 patients (average: 3.7 cm2-->1.5 cm2), unchanged in one patient and increased in 6 patients (average: 17 cm2-->2.9 cm2). The change of MR area corresponded with the change of mitral annular diameter in 23 patients but uncorresponded in 2 patients. MR areas correlated exponentially with mitral annular diameters and the fair linear relation was observed between the postoperative to preoperative ratio of MR area and the postoperative increase in mitral annular diameter with the correlation of r = 0.81. When the larger MR area or mitral annular diameter before CABG was observed, the larger MR area after CABG remained, but annular diameter before CABG had more effect on postoperative MR area. No significant correlation was found between MR area and infarcted region, revascularized region, segmental wall motion etc. In conclusion, when the moderate or marked mitral annular dilatation was found in association with prominent ischemic mitral regurgitation, mitral annuloplasty with CABG should be considered.

[Surgical treatment of incomplete endocardial cushion defect in elderly patients]

We experienced 5 surgical cases of incomplete endocardial cushion defect who were 50 years old or older. Preoperatively, 3 cases were in New York Heart Association (NYHA) class II and 2 in class III. Catheterization study showed that systolic pulmonary arterial pressure was 24 to 48 (average; 38) mmHg and pulmonary-to-systemic flow ratio was 3.4 to 8.1 (average; 5.2). Left ventriculography showed mitral valve regurgitation (grade I-1 cases, grade II-3, grade III-1) with cleft and goose neck sign in all cases. Single atrium and patent foramen ovalis were associated in each one case. At operation, suture of mitral cleft and patch closure of ostium primum defect from mitral valve side were performed. Postoperatively, NYHA class, cardiomegaly, pulmonary arterial pressure and mitral regurgitation improved remarkably in all patients. During the follow-up period from 18 to 126 months (average; 57), right bundle branch block and supraventricular arrhythmia in electrocardiogram disappeared in 3 of 4 and 4 of 5 cases, respectively. Surgical treatment and postoperative course of incomplete ECD were reviewed in over-50-year-old patients, in reference to 17 surgical cases in Japan.

[Aortic arch reconstruction without aortic cross-clamping using separate extracorporeal circulation]

Between March 1991 and October 1992, 21 consecutive patients underwent aortic arch reconstruction without aortic cross-clamping using separate extracorporeal circulation in combination with retrograde blood cardioplegia (Non-clamping selective cerebral perfusion). Twelve patients had true arch aneurysm, 3 had acute aortic dissection and 6 had chronic aortic dissection including 2 redo cases. Cardiopulmonary bypass (CPB) was instituted with an arterial cannula in the femoral artery and 2 cannulae in both vena cavae. When tympanum temperature was lowered to 20 degrees C by central cooling, CBP was stopped temporarily. As soon as the aortic arch was incised longitudinally together with aneurysm, flexible 12 Fr. balloon cannulae were inserted into the three arch arteries via their orifices and selective cerebral perfusion was started. The perfusion flow was kept between 0.3 L/m2/min and 0.35 L/m2/min with the pressure of catheter tip from 30 to 60 mmHg to keep tympanum temperature 18 degrees C. Heart was protected by retrograde continuous cold blood cardioplegia. During arch correction, the descending aorta was occluded by a balloon then abdominal viscera were perfused via a femoral return cannula and rewarming to 25 degrees C was started to prevent visceral organ failure and coagulopathy. The time of separate perfusion ranged 20 to 161 minutes with a mean of 99.9 minutes. Except one patient who died of pneumonia, 20 patient (95.2%) were discharged and doing well. No cerebral complication, myocardial infarction, lung bleeding and coagulopathy occurred. In order to prevent the infarction by debris and to protect vital organs, this method is reliable for aortic arch reconstruction.

[Surgical treatment of coronary artery-pulmonary artery fistula]

We experienced 4 cases of left coronary artery-pulmonary artery fistula. Two cases had small fistulas associated with atherosclerotic coronary lesions, and the other 2 had large fistulas with aneurysmal enlargement. In the former 2 cases, ligation of the fistulas and closure of the opening of fistula into the pulmonary artery through pulmonary arteriotomy were performed together with coronary artery bypass grafting and left ventricular aneurysmectomy. In one of the latter 2 cases, the fistula arising from the anterior descending branch was ligated and the opening of fistula draining into the pulmonary artery was closed through pulmonary arteriotomy. In another case, both openings of the fistula into the anterior descending branch and the pulmonary artery were closed from inside through incision of the dilated fistula. In all 4 cases, operations were performed using cardiopulmonary bypass and retrograde coronary perfusion, which could afford good heart protection even in cases with coronary lesions and coronary steal phenomenon. All cases went an uneventful postoperative course. Postoperative angiograms showed disappearance of the fistulas in 3 cases. In one case, however, residual fistula was found because a fine fistula might be overlooked. In such a case with complicated fistulas with aneurysmal enlargement, fistulas should be examined carefully through incision of the enlarged anomalous vessels. In this paper, diagnosis, operative indication and treatment for coronary artery-pulmonary artery fistula were discussed.

Surgical treatment of cardiac myxoma and its complications

A total of 20 patients (15 women, five men) were operated on for cardiac myxoma. Their ages ranged from 17 to 74 (mean 56) years. Myxoma was located in the left atrium in 18 patients and in the right in two. Systemic embolism occurred in eight patients, causing cerebral infarction in three, ischaemia of the extremities in two, occlusion of the external carotid artery with cerebral infarction in one, myocardial infarction in one and pulmonary infarction in one. Five patients with severe congestive heart failure required emergency surgery. All myxomas were removed using cardiopulmonary bypass with excision of the attachment walls. Details are given of additional surgery performed on some of the patients. Two patients died, one from pulmonary insufficiency after emergency surgery and the other from an unrelated problem. The remaining 18 patients showed a good recovery and are doing well with no intracardiac recurrence, although one with cerebral infarction underwent clipping of an aneurysm, which was detected later in the infarcted area.

[Surgical treatment of thoracic and thoracoabdominal aneurysm during partial cardiopulmonary bypass]

We operated on 3 patients with thoracic or thoracoabdominal aneurysm using partial cardiopulmonary bypass with right atrial drainage. The first patient was in the preshock state with severe chest and back pain. The aortography and enhanced computed tomography showed a thoracic aneurysm of 70 mm in maximum diameter ruptured into the extrapleural space and an emergency surgery was performed. The second patient was also in the preshock state with chest and back pain. The enhanced computed tomography showed a thoracoabdominal aneurysm of 120 mm in maximum diameter ruptured into the bilateral pleural spaces and an emergency surgery was performed. The third patient had a thoracoabdominal aneurysm of 60 mm in maximum diameter with a low pulmonary function. In all 3 cases, a perfusion cannula was inserted in the femoral artery and a drainage cannula was placed in the right atrium through the femoral vein. In the first case, an additional perfusion cannula was inserted into the axillary artery in order to secure the cerebral flow even at the time of intraoperative massive bleeding from the aneurysm. In all 3 cases, the approach for aneurysm was through spiral incision and aneurysms were replaced by graft inclusion technique. All 3 patients had an uneventful postoperative course and are doing well. In surgical treatment of thoracic and thoracoabdominal aneurysm, usefulness of partial cardiopulmonary bypass using right atrial drainage was discussed.

Development of an all-in-one percutaneous cardiopulmonary support system

This paper deals with development of an all-in-one percutaneous cardiopulmonary support (PCPS) system. In recent years, PCPS has been used for the treatment of acute myocardial infarction. A prototype of a compact all-in-one PCPS system was developed. The system contains a centrifugal pump and an extra-capillary flow-type membrane lung in one body. The system has a priming volume of 250 ml, which allows for PCPS with no additional blood. The in vitro tests and an ex vivo test were conducted. The system produces 1.6-5 L/min of flow in the experiments. The O2 transfer rate was 310 ml/min, and the CO2 transfer rate was 300 ml/min at a blood flow rate of 5 L/min. This device is compact, requires less priming volume than a standard system, and is easy-to-handle in the experiments. The system is considered applicable to percutaneous cardiopulmonary support.

[Surgical treatment of left atrial myxoma with concomitant acquired heart disease]

Among 21 patients with left atrial myxoma treated during the past 11 years in our institute, 3 patients had associated acquired heart disease which required concomitant cardiac surgery. Two patients had atherosclerotic coronary arterial disease, and underwent single coronary artery bypass grafting (CABG) and 4 CABGs in addition to removal of myxoma, respectively. Both of them received CABGs after removal of myxoma, because the intraoperative heart protection using retrograde coronary perfusion could afford the situation. Another patient had a huge left atrial myxoma associated with mitral and tricuspid regurgitation. She suffered from sudden heart failure caused by tumor obstruction of blood flow across the mitral valve, and an emergency surgery was performed. She underwent mitral valve replacement for annular dilatation with prolapse of both leaflets and tricuspid annuloplasty for annular dilatation, in addition to removal of myxoma. All of these 3 patients went a good postoperative course and are doing well now with no local recurrence. In this paper, preoperative and intraoperative evaluation, and surgical treatment of associated heart disease with left atrial myxoma were discussed.

[Medtronic model 6500 temporary myocardial pacing lead: a report of clinical assessment until three weeks after cardiac surgery]

Medtronic model 6500 heart wire as a right ventricular electrode was assessed in 41 postoperative cases. R-wave amplitude, slew rate, peak-to-peak, output, current, and resistance were measured by Medtronic A-V pacing system analyser, model 5311, for three weeks after open heart surgery. These parameter changed until the 7 th postoperative day, but did not change significantly thereafter. Output and current did not exceed beyond 10 V and 20 mA respectively, where there is limitations of usually available pacemaker. No complication was encountered. These results showed that this heart wire was reliably useful even until 3 weeks after open heart surgery.