Changing predictors of postoperative mortality in acute type A aortic dissection. Is only coronary artery compromise significant?

OBJECTIVES: Rapid emergency transport and early diagnosis and surgical treatment for acute type A aortic dissection have improved postoperative survival, which has, however, plateaued at about 80%. End-organ malperfusion is regarded as a strong predictor of postoperative mortality, replacing factors such as cardiac tamponade complications, aortic rupture, and left ventricular dysfunction due to aortic insufficiency. It is thus important to reevaluate risk factors for surgical death to assess current therapeutic strategies. METHODS: We statistically analyzed potential risk factors for perioperative death in 88 patients undergoing surgical repair for type A aortic dissection between January 1990 and December 1999. RESULTS: Univariate analysis showed that cardiopulmonary arrest (adjusted odds ratio: 13.78; p < 0.01) and malperfusion of more than 1 vital organ (adjusted odds ratio 4.97, p < 0.01), especially myocardial ischemia due to coronary artery dissection (adjusted odds ratio 3.21, p < 0.05), significantly increased the likelihood of operative death. Multivariate logistic regression analysis showed only cardiopulmonary arrest (p < 0.01) and concomitant coronary artery bypass grafting necessitated in cases complicated by evolving myocardial infarction (p < 0.05) to be independent predictors of postoperative mortality. CONCLUSION: Preoperative complication from coronary dissection was the most important predictor of early postoperative mortality in this series. In such cases, rapid surgical intervention before myocardial infarction develops is vital to saving lives.

Traumatic cardiac rupture with acute ascites.

A rare accumulation of serous ascites following traumatic cardiac rupture is reported for a 21-year-old man transferred to the emergency center of our hospital from a community hospital suffering from severe shock due to a motorcycle accident. Computed tomography scan showed moderate pericardial and intrapelvic fluid accumulation strongly suggesting cardiac and visceral injuries. An emergency sternotomy disclosed a rupture of the right atrial appendage, successfully closed with primary sutures. A laparotomy was done to aspirate moderate serous fluid, which was clear and not bloody. Edema of the retroperitoneal space and hepatic congestion were noted with no accompanying organ injury. Ascites pathogenesis is unknown but appeared to be related to portal venous congestion induced by cardiac tamponade combined with massive intravenous fluid infusion done to correct the patient's deteriorating hemodynamics.

Purulent pericarditis due to group B streptococcus and mycotic aneurysm of the ascending aorta: case report.

A 61-year-old female, with a history of uterine and cervical cancer treated with radical hysterectomy and 2 years of postoperative chemotherapy, presented to the emergency department with dyspnea on exertion. Computed tomography of the chest revealed a large pericardial effusion and a sacciform aneurysm of the ascending aorta. The patient subsequently underwent emergency pericardiocentesis with drainage of approximately 330 ml of a bloody and turbid effusion. Cultures from the effusion yielded group B streptococcus. Multiple organ failure and disseminated intravascular coagulation syndrome occurred in the acute phase, but gradually improved with continuous antibiotic therapy. On the 194th hospital day, in situ reconstruction of the ascending aorta was successfully performed using a synthetic graft. Although rarely reported, both purulent bacterial pericarditis and mycotic aneurysm can be life-threatening.

Argatroban, an attractive anticoagulant, for left heart bypass with centrifugal pump for repair of traumatic aortic rupture.

Systemic heparinization often increases the risk of fatal bleeding from other injured organs in surgical repair of the aorta using extracorporeal circulation in patients with traumatic aortic rupture associated with multisystem injuries. We used an antithrombin agent, argatroban, as an alternative anticoagulant in left heart bypass with the Bio-Medicus centrifugal pump in 7 of 9 recent patients who underwent aortic repair using left heart bypass. All these patients survived without obvious evidence of systemic thromboembolization. Surgical treatments for other organ injuries were carried out in 3 patients concomitantly or immediately after aortic repairs without undue blood loss. Argatroban may have a complementary effect for preventing thrombus formation without aggravating bleeding tendency because of its monotarget specificity to thrombin. We believe intravenous administration (0.5 to 2 micrograms/kg/min) of argatroban is a safe anticoagulant for left heart bypass in repairs of traumatic aortic rupture associated with multiple organ injuries.

Is the difference in alpha-amylase activity in the strains of Drosophila melanogaster with different allozymes due to transcriptional or posttranscriptional control?

The alpha-amylase in Drosophila melanogaster is a highly polymorphic enzyme, at both the allozyme level and the specific activity level. This enzyme changes its specific activity drastically depending on both food conditions and developmental stages, and it has been suggested that the ability to change its activity depending on the source of food has positive correlation with fitness. But the cause of the difference of specific activity among strains and food compositions is not known. In order to investigate the cause of these differences, we measured both the specific activity of amylase and the relative amount of Amy mRNA in eight strains of D. melanogaster with different electromorphs, in two food environments and two developmental stages. We found the following. First, the food-dependent activity change is regulated at the transcription level. Second, there was a significant correlation between specific activity and mRNA level among strains. So 80 to 90% of the specific activity difference can be explained by differences in the level of mRNAs, but the remaining part cannot. Finally, there were significant differences in specific activity per mRNA both among strains and between developmental stages. This suggests that there are differences in the catalytic efficiency of each allozyme, strain- or stage-specific translation rate, enzyme stability, or differential use of two Amy loci.

Primary mediastinal seminoma. Efficacy of chemo-radiotherapy alone.

A treatment policy must be established for primary mediastinal seminoma. We have treated five patients with this entity during 18 years. All our patients presented with a bulky mass as is usual for this disease. Our first patient was treated surgically and then with radiation, but developed recurrences and died 11 years after the initial diagnosis. Three subsequent patients, one with multiple lymph node metastases, were treated with radiation followed by cisplatin. Our most recent patient received two courses of adriamycin-reinforced PVB, and then radiation for consolidation, followed by another course of chemotherapy. For these five patients, the 5- and 10-year survival rates were both 100%. A review of the literature emphasized the fact that either radiation or surgery has recently been replaced by chemotherapy as the front-line treatment of this rare tumor in light of a better response to the latter form of treatment. We fully agree with this policy. Based on the favorable long-term results of our patients we conclude that chemo-radiotherapy can cure primary mediastinal seminoma, even in its extended form, without surgery. An initial three courses of cisplatin-based chemotherapy like adriamycin-reinforced PVB or BEP should be followed by radiation of up to 4,000 cGy for consolidation. Surgery may play a limited role for tumors that are small at presentation, or for any possible viable residue seen on roentgenograms following chemo-radiotherapy.

Bronchial wall schwannoma removed by sleeve resection of the right stem bronchus without lung resection.

A 28-year-old man presented with a bronchial wall schwannoma occurring in the right main to the intermediate bronchus. The tumor was resected en-bloc with the stem bronchi without pulmonary resection. Airway reconstruction consisted of an end-to-end anastomosis of the intermedius bronchus to the right main bronchus, and an end-to-side anastomosis of the right upper lobe bronchus to the lateral wall of the trachea. Postoperative course was uneventful. Bronchoplastic procedure with preservation of the lung parenchyma seems to be the technique of choice for benign tumors occurring intramurally in the stem bronchus.

Two cases of torsion of the gallbladder diagnosed preoperatively.

BACKGROUND: The authors experienced two cases of torsion of the gallbladder, both of which were correctly diagnosed preoperatively. METHODS: Two boys, aged 4 and 5 years, were transferred to Yokohama City Seibu Hospital because of their acute abdominal disorders. Diagnostic imaging demonstrated acute inflammatory changes in the gallbladder with an abnormal arrangement of the gallbladder and common bile duct in both cases. Laparotomy findings showed torsion of the gallbladder by 180 degrees and 360 degrees, respectively, at the cystic ducts, resulting in gangrenous change. RESULTS: Both children recovered uneventfully after cholecystectomy. The diagnostic imaging criteria are (1) collection of fluid between the gallbladder and the gallbladder fossa of the liver, (2) a horizontal rather than vertical arrangement of the long axis of the gallbladder, (3) the presence of a well-enhanced cystic duct located on the right side of the gallbladder, and (4) signs of inflammation including marked edema with thickening of the wall. CONCLUSIONS: The authors report the clinical characteristics of this uncommon condition, and discuss the significance of accurate preoperative diagnosis of these acute surgical disorders.

Influence of combined use of selenious acid and SH compounds in parenteral preparations.

The influence of the combined use of selenious acid and SH compounds (glutathione (GSH) and cysteine (Cys), or ascorbic acid (Asc)) on cultured venous vascular cells was investigated experimentally. When cultured human umbilical venous vascular endothelial cells were exposed to 10 microM of selenious acid combined with 0.5 mM-GSH or 0.5 mM-Cys, the release rates of [3H]-adenine and lactate dehydrogenase (LDH) from cells into the medium increased significantly as compared with after exposure to selenious acid alone, and damage to the vascular endothelial cells was found to be intensified. Addition of 1 microM of selenious acid simultaneously with 0.5 mM-GSH or 0.5 mM-Cys showed no differences in toxicity for the vascular endothelial cells as compared with the addition of selenious acid alone. On the other hand, simultaneous exposure to 10 microM of selenious acid and 1 mM-Asc induced no significant differences in the release rates of [3H]-adenine and LDH, and no damage was observed to the vascular endothelial cells. These results suggest that simultaneous addition of selenious acid together with GSH or Cys, which have the SH-group, may cause damage to the vascular endothelial cells. Therefore careful attention is warranted in total parenteral nutrition (TPN).

Digestive tract disorders associated with asplenia/polysplenia syndrome.

The authors reviewed experience gained over a 20-year period of asplenia or polysplenia syndrome, focusing on patients with associated digestive tract disorders (DTDs). Eleven of 27 patients (40%) with asplenia/polysplenia had associated DTDs. The DTDs comprised malrotation of the intestine in nine, both preduodenal portal vein and gastric volvulus in three, esophageal hiatal hernia in two, and biliary atresia in one. Laparotomy was carried out on four patients with symptoms of acute bowel obstruction and on one patient with biliary atresia. One patient with both malrotation and gastric volvulus, and another with only associated malrotation survived. Nine patients died, eight of cardiac insufficiency and one because of hepatic insufficiency. When infants are diagnosed with heterotaxia, they should be examined for other combined DTDs, because they may have a chance for survival if they undergo surgery when their condition is still stable.

Immunologic reaction and genetic factors in biliary atresia.

The characteristic histopathological features seen in the livers of patients with biliary atresia (BA) are very similar to those of primary biliary cirrhosis, which is an autoimmune disease. To clarify whether BA liver possess an immunological response similar to that in primary biliary cirrhosis, we studied HLA-DR expression in liver tissue of BA patients, using a HLA-DR staining method, and determined the frequency of HLA types in BA patients and their families. HLA-DR was expressed by the bile duct epithelium in 11 of 16 liver specimens obtained from 13 BA patients. By contrast, HLA-DR was not expressed in liver specimens from 6 patients with congenital biliary dilatation. Among the HLA types seen in BA patients and their families, HLA-A33, -B44 and -DR6 were frequently expressed in blood. These results suggest that certain immunological factors and disease-susceptible genes might be involved in the etiology of BA.

[Emergency myectomy in a patient with hypertrophic obstructive cardiomyopathy complicated with left heart failure and cardiac arrest].

Major cause of death in HOCM is sudden death due to ventricular arrhythmias, and only 10% of the death is caused by congestive heart failure. We report a 38-year-old woman of HOCM complicated with lung edema and cardiac arrest due to acute left heart failure. Intraventricular pressure gradient showed 125 mmHg in previous study, and echocardiogram demonstrated evidences suggestive of terminal-staged HOCM. After unsuccessful attempts of intravenous propranolol administration, emergency myectomy of left ventricular outflow tract was carried out. Postoperative course was uneventful, and intraventricular pressure gradient was relieved. The patient is now asymptomatic without medication after 1 years of operation. This case suggests that emergency myectomy may be a choice to relieve refractory congestive heart failure in patient with HOCM.

[Anticoagulant therapy and obstetric management in a pregnant patient with mechanical prosthetic valve].

A 30-year-old female whose mitral valve had been replaced with a mechanical prosthetic valve 23 years ago gave birth to a healthy baby by cesarian section under controlled anticoagulant therapy. Warfarin was replaced with intravenous heparin just one week before cesarian section and heparin administration was stopped several hours prior to the operation which was successfully carried out without excessive blood loss. Although warfarin carries a risk of teratogenecity, fortunately, the baby had not any somatic malformation. We believe that pregnancy is not contraindicated in patients with mechanical prosthetic heart valves, however, a strict observation of the cardiac function during middle and late trimesters of gestation by echocardiography and planned anticoagulant therapy are necessary in order to prevent maternal congestive heart failure and thromboembolism and protect a neonate against intracranial hemorrhage.

[Surgical treatment of aortic valve endocarditis associated with aortic root aneurysm and abscess].

Between Jan. 1979 and Mar. 1996, aortic root abscess and aneurysm were encountered in 10 (34.5%) of the 29 patients who underwent surgical treatment for the aortic valve endocarditis ; native valve endocarditis (NVE) in 8 and prosthetic valve endocarditis (PVE) in 2. Noncoronary sinus was involved in 8 (80%) of 10 patients, left coronary sinus destructed in one, and more than one sinus were involved in one. All patients underwent aortic valve replacement after repair of abscess or aneurysm with suture closure in 5, and patch closure in 3, and its resection in one. Aortic root reconstruction using a valved conduit was required for the repair of aortico-ventricular discontinuity followed debridement of the abscess cavity of almost entire annulus in one PVE patient who consequentry died of LOS and sepsis. There was no operative or postoperative death in the other patients, however, one female patient suddenly died 24 months after surgery. She underwent direct suture closure of left coronary sinus aneurysm and aortic valve replacement with a small-sized prosthetic valve. Suture dehiscence of the orifice of the aneurysm developed immediately after surgery. It is concluded that patch closure of aortic root aneurysm or abscess is recommended so as to avoid narrowing of left ventricular outflow tract and recurrence of aneurysm formation even if its orifice proved to be small.

[Traumatic thoracic aortic rupture--diagnosis and surgical repair].

Fifteen cases of traumatic thoracic aortic rupture (TAR) were treated at St. Marianna University Hospital from December 1980 to July 1995. Causes of TAR were due to vehicle accidents in 14 patients and fall in one patient. On diagnosis, contrast-enhanced CT scan was routinely performed in the patients with blunt chest trauma associated with superior mediastinal widening, loss of the aortic knob or right shift of the trachea on the initial roentgenogram. When CT scan demonstrated specific signs for TAR, pseudoaneurysm formation and/or extravasation of the contrast dye, aortography was eliminated before operation. As a role, operation was performed on an emergency basis as soon as the diagnosis was confirmed. Four cases died due to intrapleural rupture before or immediately after thoracotomy. Nine (82%) of the 11 patients in whom operation was completed survived and are doing well. In one of the 4 patients who underwent operation with simple aortic cross-clamping; paraplegia developed after 30 minutes of spinal ischemia. Left heart bypass with the Bio-Pump without heparin or with an antithrombin agent, argatroban, was used in recent 6 patients. Use of left heart bypass with the Bio-Pump without anticoagulant or with argatroban appears to be promising as a safe adjunct in the repair of TAR, preventing fatal bleeding of other injured organs.

Selenium administration to a ten-year-old patient receiving long-term total parenteral nutrition (TPN)--changes in selenium concentration in the blood and hair.

Muscle pain in the lower limbs occurred in a child with short bowel syndrome who has been receiving longterm total parenteral nutrition (TPN). Biochemical parameters revealed that the plasma and erythrocyte selenium concentrations were below the normal range for children and intravenous injection of selenium prepared from selenious acid was started at a dose of 100 micrograms per day. Muscle pain in the lower limbs disappeared one month afterwards. At this point in time, the elevation of the plasma selenium concentration was noted but the erythrocyte selenium concentration remained low. When administration was suspended due to catheter-induced fever five months later, the whole blood selenium concentration decreased again and the symptoms recurred. Accordingly, the dose of selenium was increased to 200 micrograms/day. Subsequently, the blood selenium concentration recovered to the normal range for children. After the dose increase to 200 micrograms/day, concentrations in hair samples collected at every centimeter distance from the root end were determined. The selenium concentration at the root end was found to be higher than the normal range for children, indicating that this was an excessive dose case. Although the dose was decreased from 200 micrograms/day to 120 micrograms/day, the plasma and erythrocyte selenium levels did not go down. Furthermore, the selenium level in the hair reached a plateau, and no recurrence of symptoms was observed. The above results indicate the usefulness of monitoring the selenium concentration in hair in addition to determining the blood selenium level and GSH-Px activity in administering selenium to children undergoing TPN.

A case report of simultaneous surgery for Wolff-Parkinson-White syndrome combined with hemolytic anemia and mitral stenosis.

A 46-year-old woman with mitral stenosis, WPW syndrome, hemolytic anemia due to spherocytosis, and hypothyroidism with Hashimoto's thyroiditis, was admitted with palpitations and dyspnea due to paroxysmal atrial fibrillation with a rapid ventricular response, and was treated by electrical cardioversion. We selected surgical intervention to treat the mitral stenosis and WPW syndrome, as some tachycardia episodes due to atrial fibrillation have resulted in repeated congestive heart failure. In 1983 we simultaneously performed a division of the posteroseptal accessory pathway and a mitral valve replacement with a bioprosthetic valve under cardiopulmonary bypass, using a membrane oxygenator after splenectomy to compensate for the hemolytic anemia due to spherocytosis. Her postoperative course was favorable and she is now in good health with no episodes of tachycardia, congestive heart failure nor anemia occurring during the 10 years that have followed the operation. Simultaneous surgery for WPW syndrome combined with other cardiac abnormalities and hematologic disorders achieved acceptable results in this case.

Continuous monitoring of short-latency somatosensory evoked potentials during cardiac and aortic surgery.

The effectiveness of monitoring somatosensory evoked potentials (SEPs) intraoperatively to detect brain damage early remains controversial. To assess the diagnostic accuracy of this modality, a study was conducted between 1991 and 1994, recording SEPs in 287 consecutive patients undergoing cardiac and aortic surgery using cardiopulmonary bypass (CPB) with moderate hypothermia or deep hypothermic circulatory arrest. From P1 to N2 of the SEPs occurring within 50 ms latency in response to electrical stimulation of the median nerve were recorded over the contralateral postcentral cortex at 5-min intervals using a Neuropack-2 (Nihon Koden, Tokyo, Japan). Normal SEPs were recovered in 247 patients postoperatively; however, 2 of these patients had suffered a cerebral infarction and 1, a transient stroke intraoperatively, demonstrating a false-negative incidence of 1.2%. On the other hand, three different types of abnormal SEPs were recorded postoperatively. P1 and N1 absence, probably caused by a subcortical lesion, was observed in 4 patients; P2 and N2 absence, probably caused by a cortical lesion, was observed in 8 patients; and a flat SEP, representing diffuse damage, was observed in 2 patients. Among these 14 patients with abnormal SEPs, 7 showed no neurologic disturbance at all, demonstrating a false-positive incidence of 50%. Thus, we concluded that when normal SEPs are recovered during weaning from CPB, the incidence of brain damage could be predicted at below 5%. Conversely, when abnormal SEPs are demonstrated, the incidence of brain dysfunction impeding a return to active life is estimated to be about 70%.

Bilateral intralobar pulmonary sequestration.

A 34-year-old male presented with an infected intralobar pulmonary sequestration of the left lower lobe. Aortography revealed bilateral anomalous systemic arteries, originating in the lower level of the descending thoracic aorta, to the lower lobe on each side. The portion of the right lower lobe, which was perfused by the anomalous systemic artery was seen otherwise normal in anatomy without any recognizable sequestered lung tissue. The patient underwent a left postero-lateral thoracotomy on June 22, 1994. Each aberrant artery was recognized to take off from a common branch of the descending aorta at the level of the diaphragm. A left lower lobectomy with division of the left aberrant artery as well as ligation of the right anomalous artery were done. A postoperative pulmonary perfusion scan depicted normal uptake of radioactivity in the right lower lobe, suggesting normal pulmonary arterial perfusion to the area receiving previously the anomalous systemic arterial flow. An anomalous systemic artery perfusing an otherwise normal lung can be classified as one of the forms of intralobar pulmonary sequestration and could be ligated without resection of the involved area of the lung.