The distribution of alpha-melanocyte stimulating hormone (alpha-MSH) in the central nervous system of the rat: an immunohistochemical study. II. Lower brain stem.

The distribution of immunoreactive alpha-melanocyte stimulating hormone (alpha-MSHI) in the rat lower brain stem was examined by indirect immunofluorescence or peroxidase- anti-peroxidase immunohistochemical method using an antiserum against synthetic alpha-MSH. The results confirmed the presence of alpha-MSHI fibers in the midbrain central gray matter and parabrachial area, and demonstrated a much more extensive distribution of these fibers in various parts of the lower brain stem areas previously thought not contain alpha-MSHI fibers. In addition, the commissural nucleus was identified as a new alpha-MSHI neurons-containing site. No alpha-MSHI neurons were seen in other regions of the rat lower brain stem.

Pericardial hood repair of cardiac rupture secondary to extended myocardial infarction.

A surgical technique for simple and safe repair of oozing-type postinfarction cardiac rupture secondary to extended myocardial infarction is described. A hood-shaped pericardium was glued with gelatin-resorcinol and formaldehyde glue to cover the extended oozing infarcted myocardium. This technique was used on 3 elderly patients with good results.

Comparison between pulsatile and nonpulsatile circulatory assist for the recovery of shock liver.

In patients with prior shock and liver injury, mechanical circulatory assist still has a high risk of hepatic failure. The purpose of this study was to evaluate the effect of mechanical circulation using pulsatile or nonpulsatile blood pumps on shock organs, particularly shock liver. In 14 dogs, a shock liver model was produced by clamping the descending aorta above the diaphragm. After 60 minutes of ischemia, left atrial-femoral artery bypass (LHB) was started while the clamp remained in place. A pneumatic pulsatile pump (Toyobo; Tokyo, Japan) was used in seven dogs (Gr-PP) and a centrifugal pump (Biomedicus; Minneapolis, MN) in seven (Gr-NPP). In both groups the mean arterial pressure was maintained at 80 mmHg. The mean bypass flow was 96 +/- 14 ml/kg/min for Gr-PP, and 95 +/- 35 ml/kg/min for Gr-NPP. In both groups the bile flow and arterial ketone body ratio decreased significantly after ischemia, and recovered to normal after 120 min of LHB. There was no significant difference between the two groups in this model. The other parameters (glutamic oxaloacetic transaminase [GOT], glutamic pyruvic transaminase, lactate dehydrogenase, mitochondrial GOT) were independent of the period of ischemia and reperfusion, and there was no difference between the two groups. In conclusion, these results suggest that nonpulsatile circulatory assist may not be disadvantageous for the circulatory support and recovery of liver function in the setting of shock liver.

Improved management of selective cerebral perfusion in aortic arch surgery.

To establish a safe and reliable method for cerebral protection in aortic arch surgery, the authors attempted antegrade selective cerebral perfusion (SCP) based on the characteristics of jugular venous oxygen saturation (SjO2). Twenty patients were divided into two groups: a control group and SCP group. In the control group, in 13 adult patients undergoing cardiac surgery using standard hypothermic cardiopulmonary bypass, the relationship between SjO2 and nasopharyngeal temperature (NPT) during rewarming showed an inverse linear correlation:SjO2 = -2.3 NPT + 133 (r = 0.616). In the SCP group, seven patients with aortic arch aneurysm underwent surgery using SCP performed through direct cannulation of the innominate and left carotid arteries. While on SCP (83 +/- 24 min), the blood was warmed from 28 to 36 degrees C. Cerebral perfusion pressure of 40-60 mm Hg was necessary to maintain the SjO2 equal to the value in the control group at each NPT during SCP in all seven patients. None of the patients had any post operative complications. Our experience suggests that SCP can be safely performed at both mild hypothermia and normothermia under monitoring of perfusion pressure and SjO2 in aortic arch surgery.

Heat generation and hemolysis at the shaft seal in centrifugal blood pumps.

The heat and hemolysis around a shaft seal were investigated. Materials were original pumps (Nikkiso HMS-15:N-original, and 3M Delphin:D-original), vane-removed pumps (Nvane(-), Dvane(-)), and a small chamber with a shaft coiled by nichrome wire (mock pump). The original pumps were driven at 500 mmHg and 5 L/min, and vane-removed pumps were driven at the same rotation number. An electrical powers of 0, 0.5, 2, and 10 W was supplied to the mock pumps. In vitro hemolytic testing showed that hemolytic indices were 0.027 g/100 L in N-original, 0.013 in Nvane(-), 0.061 in D-original, and 0.012 in Dvane(-). Measurement of heat with a thermally insulated water chamber showed total heat within the pump of 8.62 and 10.85 W, and heat at the shaft seal of 0.87 and 0.62 W in the Nikkiso and Delphin pumps, respectively. Hemolysis and heat generation of mock pumps remained low. The results indicate that the heat generated around the shaft seal was minimal. Hemolysis at the shaft-seal was considerable but not major. Local heat did not affect hemolysis. It was concluded that the shaft-seal affected hemolysis, not by local heat but friction itself.

Acute phase responses of vasoactive hormones to non pulsatile systemic circulation.

Acute phase responses of vasoactive hormones to the rapid conversion of a systemic flow pattern from pulsatile or non pulsatile mode to the reverse were assessed in 20 goats weighing 45-69 kg. A total left heart bypass was instituted under general anesthesia, with pulsatile and non pulsatile pumps interposed in the circuit in parallel, and the systemic flow mode was rapidly and bidirectionally converted from the pulsatile mode or non pulsatile mode to the reverse. Vasoactive hormone levels and hemodynamics were evaluated before and after 5 min of conversion. No significant difference was observed between the modes either in blood flow or systemic vascular resistance, while the mean aortic pressure was significantly higher in the non pulsatile mode than the pulsatile mode (106.7 +/- 2.4 versus 99.9 +/- 3.5 mmHg). Among various vasoactive hormone levels evaluated, only norepinephrine showed a significant difference between the modes, where concentration in the non pulsatile mode was significantly higher than the pulsatile mode (391.0 +/- 60.7 versus 309.4 +/- 42.5 pg/ml). No correlation was found between the absolute values of mean aortic pressure and norepinephrine level, whereas a significant reciprocal correlation was detected between the magnitude of inter-mode differences in these two parameters. In conclusion, a non pulsatile systemic circulation does not exert significant influence on vasoactive hormone levels, except for slight increase in norepinephrine with a reciprocally correlated increase in mean aortic pressure. It is deduced that activity of the sympathetic nervous system represented by norepinephrine level is higher in the non pulsatile mode than the pulsatile mode, and the baroreceptor reflex functions in an acute phase after flow mode conversion.

Clinical experience with long-term use of the Toyobo left ventricular assist system.

The Toyobo-NCVC extracorporeal pneumatic left ventricular assist system (LVAS) was used in four patients with advanced dilated cardiomyopathy. The duration of support ranged from 46 to 390 days (mean, 206 days). In all patients, stable hemodynamics were achieved with 3.5-5.5 L/min flow rates. Two patients survived long term. One was transported to the United States by a chartered jet while on LVAS and successfully underwent heart transplantation after 119 days of support. The other is on LVAS and is doing well for 390 days. The remaining two patients died of multi-organ failure while their hemodynamics were quite stable under LVAS. In these two patients, severe hepatic failure had developed before LVAS implantation. Minor cerebral embolisms occurred in the two survivors, but neither of them experienced permanent neurologic deficits. In only the initial patient were major thrombi noted on the diaphragm of the pump; the thrombi required pump exchange four times during 119 days. In the patient supported for 390 days, a small tear in the diaphragm was observed after 209 days of support, and the pump was safely exchanged. It is suggested that the Toyobo LVAS can provide consistent and reliable performance for long-term use.

Power of the fatigue resistant in situ latissimus dorsi muscle.

To evaluate the in situ latissimus dorsi muscle as an actuator for circulatory assistance, 1) muscle power was analyzed in animal experiments, and 2) muscle weight was measured in human cadavers. Three adult goats underwent 12 week preconditioning. The insertion of the latissimus dorsi muscle was then connected to a spring and a tension transducer in series. The stroke length was measured with a photosensor without power loss. With contraction of muscles under various loads, tension-length relationships at end contraction and end relaxation were obtained and the maximum area of a square drawn within both lines was assumed to be maximum external power. Good fatigue resistance and the highest maximum external power of 3.16 Watts/kg at 120 min was derived from preconditioned latissimus dorsi muscle in burst frequency of 50 Hz. Muscle weight in 42 human cadavers was negatively correlated with age (r = 0.56) and was expected to be 221.6 g in patients aged 45 years. According to these data, the power of a human preconditioned latissimus dorsi muscle was estimated as 0.7 Watts. It was concluded the power of in situ preconditioned latissimus dorsi muscles was appropriate for right heart assistance or counterpulsation for left heart assist.

Treatment of acute myocardial infarction with cardiogenic shock using left ventricular assist device.

We have treated ten cardiogenic shock patients after acute myocardial infarction (AMI) with a left ventricular assist device (LVAD). These patients were later divided into three groups: the first group with ventricular septal perforation, the second with aorto-coronary bypass grafting (ACBG) before LVAD implantation and the third group without ACBG. LVAD maintained the systemic circulation in each group, and cardiac function recovered enough to remove LVAD in 70% of the total patients. Two of three patients in the first group were discharged from hospital. Two weaned cases in the second group died of multiple organ failure and one was discharged, and hemorrhagic necrosis was seen in the bypassed area of the myocardium. One patient of the third group could not be weaned from LVAD because of respiratory failure though his heart function began to recover. Another case in the third group underwent bypass grafting after removal of LVAD. However ACBG surgery should be done very carefully because a patient in shock is occasionally intolerant to major surgery. In all groups, the major cause of death was multiple organ failure which was probably caused by the prolonged low output condition prior to LVAD application. In the light of this experience, it appears that LVAD should be applied before irreversible damage occurs to major organs, including the heart itself. To ensure the timely application of LVAD, some way must be found to introduce systematic application of LVAD into the normal course of AMI treatment.

[Analysis of left ventricular function early after coronary artery bypass grating in patients with left ventricular dysfunction].

We analyzed left ventricular (LV) function early after coronary artery bypass grafting (CABG) in patients with LV dysfunction, whose LV ejection fraction (LVEF) was less than 0.4. 11 patients were divided into two groups: Group-A patients (G-A: n = 6) improved LVEF (post-op LVEF > 0.4) and Group-B patients (G-B: n + 5) did not improve LVEF (post-op LVEF < 0.4) one month after CABG. Preoperative status of coronary artery disease, cardiac function, operative procedure, and postoperative cardiac function were compared between two groups. All patient had old myocardial infarction. There were no differences in preoperative LVEF (0.30 +/- 0.06 in G-A and 0.31 +/- 0.06 in G-B), CI, and LVEDP between two groups. LVEDVI (85 +/- 19 in G-A and 159 +/- 50 ml/m2 in G-B) and LVESVI (60 +/- 14 in G-A and 113 +/- 49 ml/m2 in G-B) values were higher in G-B, respectively. Number of grafts was not different between two groups (2.3 in G-A and 2.4 in G-B). Postoperative LVEF value (0.53 +/- 0.07 in G-A and 0.34 +/- 0.04 in G-B) was lower in G-B. Thus, it might be difficult to obtain the recovery of LV function in patients with LV dilatation, early after CABG.

[A case report of patch angioplasty of the left main coronary artery for isolated left main coronary artery disease].

A 49-year-old woman was admitted to our hospital because of palpitation and right shoulder pain. Examinations showed isolated left main coronary artery disease. Surgical angioplasty of left main coronary artery was considered. The left main stem was approached anteriorly. Pericardium was chosen for patch material and the left main coronary artery was enlarged from 1.5 to 4.0 mm in diameter. Postoperative course was very stable, and postoperative angiography revealed an excellent result.

[Coronary artery bypass grafting in six patients with familial hypercholesterolemia].

UNLABELLED: From June 1989 through November 1991, six patients with familial hypercholesterolemia underwent surgical treatments. The surgical procedures were coronary artery bypass grafting (CABG) alone 4, ligation of coronary aneurysm + CABG 1, and CABG + femoro-femoral bypass 1. There were no operative or hospital deaths. Early post operative patency rate of the grafts was 100%. CASE PRESENTATION: A 44-year-old man whose anginal pain recurred 11 years after CABG. Coronary angiogram revealed stenosis and a large aneurysm in the circumflex coronary artery. Previous grafts to the left anterior descending coronary artery and diagonal branch were patent. Ligation of the aneurysm and internal mammary artery bypass grafting were performed. Postoperatively, the patient has remained asymptomatic. Our data indicate that CABG for FH patients is effective in the early postoperative period.

[A case report of congenitally bicuspid aortic valve and ascending aortic aneurysm treated by wheat operation].

A 59-year-old man who complained of palpitation was diagnosed as having a congenitally bicuspid aortic valve, severe aortic regurgitation, and an ascending aortic aneurysm. He underwent aortic valve replacement and conduit replacement by the modified Wheat technique. Since this technique requires no coronary artery anastomosis, it causes no problems associated with reconstruction of the coronary artery. Postoperative angiogram revealed no aneurysm formation of the aortic root or paravalvular leakage. This case suggest that aneurysm of the ascending aorta with aortic regurgitation is more effectively treated by the modified Wheat technique if cephalad displacement of the coronary ostium is not extensive.

[A case report of type A acute aortic dissection, which arose from true aneurysm in aortic arch].

A 69-year-old woman was admitted to our hospital because of back pain. Examinations showed type A acute aortic dissection, which arose from true aneurysm in aortic arch, and emergency operation was considered. Deep hypothermic selective cerebral perfusion was carried out for brain protection. Ascending to aortic arch was replaced with 24 mm woven Dacron graft. There was no postoperative neurological complication.

[Two cases of severe ischemic mitral regurgitation treated with CABG alone].

We report here two cases in which patients fell into pulmonary edema due to ischemic mitral regurgitation (ischemic MR) after cardiac catheterization and underwent emergency coronary artery bypass grafting (CABG) using an intra-aortic balloon pumping. The patient were a 65-year-old man and a 80-year-old woman, and both had a chief complaint of angina after myocardiac infarction. In both cases, coronary angiography revealed triple vessel disease, and left ventriculography showed severe MR. However echocardiography, when they were hospitalized, did not show significant MR. Therefore we thought that they had gone into congestive heart failure because cardiac ischemia and volume load following cardiac catheterization provoked MR. In fact, postoperative left ventriculography and echocardiography showed decreased MR. We now think that it is important to keep in mind the cases of severe ischemic MR for which CABG alone is adequate treatment and to evaluate ischemic MR not only by left ventriculography but also by echocardiography.

[Clinical experience of reoperation for anastomotic stricture following proximal gastrectomy for esophageal varices].

A few cases were reported in which second reconstructive operation on gastrointestinal tract for reflux esophagitis following the proximal gastrectomy was performed. But no previous report of the removal of anastomotic region for treating anastomotic stricture due to reflux esophagitis has appeared. Also, there are no reports on second operations to treat anastomotic strictures following proximal gastrectomy for esophageal varices. We report a case in which we obtained favorable results in treating an anastomotic stricture due to reflux esophagitis, which developed following a proximal gastrectomy for esophageal varices, by performing removal of the anastomotic region and resection of the remaining stomach with reconstruction by the Roux-en Y method.

[Single-stage management of postoperative sternal wound infection using a pectoral musculocutaneous flap].

Two patients with postoperative sternal wound infection were successfully treated by a pectral musculocutaneous flap. A single-stage procedure of debridement and immediate closure with a pectral musculocutaneous flap can eliminate irrigation, open wound management, or reoperation for closure. Therefore, this method is very safe, simple, and effective for the management of sternal wound infections.

[The effectiveness of preservation of hepatic arterial blood flow by modified Appleby procedure with reconstruction of the hepatic artery--serial changes in postoperative liver function].

We investigated whether modified Appleby procedure with reconstruction of the hepatic artery can avoid complications due to a decrease in heptic arterial flow which has been comprehended in conventional Appleby's operation. The postoperative liver function of 17 patients undergoing modified Appleby's procedure was compared with that of 16 patients undergoing total gastrectomy and distal pancreato-splenectomy (control group). (1) Anticoagulant therapy was not required during and after operation. The common hepatic arterial flow after vascular anastomosis was 396 +/- 101 ml/min. Postoperative celiac arteriography revealed good patency of anastomosis. (2) There were no significant differences between the modified Appleby group and the control group in any of the blood levels of GOT, GPT total bilirubin and alkaline phosphatase at any point until the fourth postoperative week. In none of the patients in the modified Appleby group, the blood levels of GOT and GPT exceeded 250 IU/l. (3) In the modified Appleby group, ICG-R15 was 4 +/- 1% before operation and 6 +/- 3% at the first postoperative month. These results suggested that modified Appleby procedure enabled us to perform resection according to Appleby's operation safely, without need for preoperative or intraoperative examination about the retrograde blood flow mediated by the gastrodudenal artery.