Reduction of ischemic spinal cord injury by dextrorphan: comparison of several methods of administration.

OBJECTIVES: We investigated the effect of dextrorphan, an N -methyl-D -aspartate receptor antagonist, on the reduction of ischemic spinal cord injury and the safe clamping time after various methods of administration. METHODS: Spinal cord ischemia was induced in New Zealand White rabbits by infrarenal aortic clamping and animals were divided into 5 groups. Group A (n = 15) received simple clamping. Groups B (n = 20) and C (n = 35) received dextrorphan pretreatment (10 mg/kg), followed by continuous intravenous or intra-aortic infusion (1 mg/min), respectively. Group D (n = 25) received the same dextrorphan pretreatment and bolus intra-aortic injection at clamping (1 mg per minute of clamping time). Group E (n = 15) received bolus intrathecal injection of dextrorphan (0.2 mg/kg). Each dextrorphan-treated group had a small group of control animals (n = 5). The neurologic status was assessed by the Johnson score (5 = normal, 0 = paraplegic) 48 hours after unclamping, and animals were put to death for histopathologic examination. RESULTS: All dextrorphan-treated groups showed better neurologic function than the respective control animals (P <.001 vs groups B, C, and D; P =.014 vs group E). The order of efficacy of dextrorphan (as revealed by the average of neurologic status) was as follows: group C > group D (P =.017, after 50 minutes of clamping), group D > group B (P =.014, after 45 minutes of clamping), and group B > group E (P <.001, after 40 minutes of clamping). Histopathologic findings did not necessarily correspond with hind-limb neurologic function. CONCLUSIONS: Dextrorphan reduced the physical findings associated with ischemic spinal cord injury, and continuous intra-aortic infusion prolonged the safe clamping time significantly more than delivery by other routes.

Experimental study on the effect of antegrade cerebral perfusion on brains with old cerebral infarction.

OBJECTIVE: Patients with old cerebral infarction who undergo aortic arch operations are susceptible to postoperative neurologic dysfunction. To verify such susceptibility, we performed this experimental study. METHODS: A cerebral infarct model was created in mongrel dogs by means of injection of cylindrical silicone embolus through the internal carotid artery. The dogs that had obvious neurologic deficits 1 day later and survived for 4 weeks or more were included in the cerebral infarct model. One month after cerebral infarction was induced, deep hypothermia and selective cerebral perfusion were used in 14 mongrel dogs (infarct group, n = 7; control group, n = 7). During this procedure, serum glutamate concentration and venous-arterial lactate difference were measured. Histopathologic study of the brain was also performed. RESULTS: Changes in venous-arterial lactate difference in both groups were almost similar, except in the rewarming phase. At 32 degrees C during rewarming, the venous-arterial lactate difference in the infarct group was significantly higher than that in the control group (P =.006). Although pre-cooling concentrations of serum glutamate were similar in both groups, the values in the infarct group at the end of rewarming were significantly higher than those in the control group (P =.046). On histologic examination, the presence of old cerebral infarction with gliosis was confirmed in the infarct group, but neither new cerebral infarction nor destruction of the blood-brain barrier was found. CONCLUSION: We observed an accelerated anaerobic metabolism and an increased extracellular glutamate release in the infarct group. The brain with old cerebral infarction is more susceptible to ischemia during arch operation than noninfarcted brain.

Aortic regurgitation with dilation of ascending aorta and right coronary artery occlusion by a rudimentary aortic cusp.

Occlusion of a coronary artery ostium, especially that of the right by an aortic cusp, is a rare congenital anomaly. We had the experience of dealing with an adult patient with aortic regurgitation due to a rudimentary aortic cusp that also occluded the right coronary ostium. We performed composite graft replacement because the patient also had coexistent dilation of the ascending aorta. Postoperative course was uneventful.

Role of biologic glue repair of proximal aortic dissection in the development of early and midterm redissection of the aortic root.

BACKGROUND: Redissection of the aortic root after supracommissural aortic graft replacement with reapproximation of the layers of the dissected aortic root is relatively rare. Causes and surgical treatment of this lesion remain controversial. METHODS: From January 1983 to September 2000, 130 patients had emergency operation for acute type A aortic dissection. Of them, 57 patients underwent root reconstruction using biologic glues and 4 patients (7.0%) developed redissection of the aortic root associated with moderate to severe aortic regurgitation 5 to 27 months after the initial operation. In all patients, the proximal false lumen was obliterated with infusion of gelatin-resorcinol-formaldehyde (GRF) glue or BioGlue and the aorta was reinforced with Teflon felt strip or Surgicel placed on its outside wall. RESULTS: During reoperation, the noncoronary aortic sinus was found to be redissected in all patients with the dissection extending retrogradely to the aortic annulus. This resulted in aortic regurgitation with prolapse of the noncoronary cusp because the proximal suture line dehisced. Histopathology showed disappearance of the nuclei of the medial smooth muscle cells, suggesting tissue necrosis at the site of GRF glue application. The lesions were treated successfully with full root replacement using a freestyle heterograft bioprosthesis or a composite graft prosthesis. CONCLUSIONS: The use of biologic glues for reapproximating the layers of the dissected aortic root is associated with a certain amount of risk of aortic wall necrosis. Therefore, care should be taken to ensure proper use of these glues. Full root replacement could be a preferable technique for treating redissection of the aortic root.

Surgical treatment of annuloaortic ectasia with coronary aneurysm and fistula.

Annuloaortic ectasia associated with a giant aneurysm of the left coronary artery and a coronary artery fistula is extremely rare, and it is difficult to decide how to repair this complex lesion. The cause of the huge aneurysm of the left coronary artery in our patient was thought to be cystic medial necrosis, the coronary artery fistula, or both. The surgical management of this extremely rare pathological combination is described.

Improved results of atherosclerotic arch aneurysm operations with a refined technique.

OBJECTIVE: We sought to analyze the postoperative hospital mortality and postoperative neurologic dysfunction in patients who had total arch replacement for atherosclerotic arch aneurysms using our recent refined technique. METHODS: Between June 1997 and April 2000, 50 consecutive patients underwent total arch replacement with an aortic arch branched graft for atherosclerotic arch aneurysms. Their mean age was 71 +/- 7 years (range, 57-87 years). Forty-eight (96%) patients were operated on electively, and the remaining 2 (4%) were operated on an emergency basis because of rupture of aneurysm. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and systemic circulatory arrest during distal graft anastomosis. A total of 19 concomitant procedures were done in 17 patients. Mean selective cerebral perfusion time was 78.1 +/- 16.5 minutes. RESULTS: Overall in-hospital mortality was 2% (95% confidence intervals, 0%-5.9%). On univariable analysis, permanent neurologic dysfunction was the only risk factor for in-hospital mortality. Postoperative temporary and permanent neurologic dysfunctions were 4% (95% confidence intervals, 0%-9.4%) and 4% (95% confidence intervals, 0%-9.4%), respectively. On univariable analysis, cardiopulmonary bypass time was the only risk factor for temporary neurologic dysfunction, and history of cerebrovascular disease was the only risk factor for permanent neurologic dysfunction. There was no significant correlation between selective cerebral perfusion time and temporary and permanent neurologic dysfunction. CONCLUSION: Integrated cerebral protective effect of antegrade selective cerebral perfusion and total arch replacement with an aortic arch branched graft could substantially reduce in-hospital mortality and postoperative neurologic dysfunction in patients with atherosclerotic arch aneurysms.

Total arch replacement using aortic arch branched grafts with the aid of antegrade selective cerebral perfusion.

BACKGROUND: We report our clinical experience with total arch replacement using aortic arch branched graft in an attempt to determine the independent predictors of both in-hospital mortality and neurologic outcome. METHODS: We studied 220 consecutive patients who underwent total arch replacement using aortic arch branched graft between May 1990 and June 1999. All operations were performed with the aid of hypothermic extracorporeal circulation, antegrade selective cerebral perfusion, and open distal anastomosis. RESULTS: The overall in-hospital mortality rate was 12.7%. Multivariable analysis showed independent determinants of in-hospital mortality to be chronic renal failure, long pump time, participation in early series, and shock. Postoperative permanent neurologic dysfunction was 3.3%. On multivariable analysis, old cerebral infarct and pump time were independent determinants of permanent neurologic dysfunction. The selective cerebral perfusion time had no significant influence on in-hospital mortality or neurologic outcome. The 5-year survival rate including in-hospital deaths was 79% +/- 6%. CONCLUSIONS: Selective cerebral perfusion allows increased ease of performance of total arch replacement, a complex and time-consuming procedure, and helps reduce periprocedural mortality and morbidity in patients with aortic arch aneurysm and those with acute aortic dissection.

Surgical treatment of recurrent abdominal aortic aneurysm in a patient with systemic lupus erythematosus.

Reports of true abdominal aortic aneurysms (AAAS), especially those due to severe inflammation, in patients with systemic lupus erythematosus (SLE) are very few in number. However, we had the experience of surgically treating a recurrent AAA due to severe inflammation found in a patient with SLE. The recurrence took place after an earlier operation for an infrarenal AAA and involved the left renal artery. In both situations, the previous infrarenal aaa and the recurrence, the aneurysms demonstrated more rapid growth and more irregularities in shape. Etiology of the AAA might be a combination of Takayasu's arteritis and SLE because the two entities appeared to have overlapped.

Extended total arch replacement for acute type a aortic dissection: experience with seventy patients.

OBJECTIVE: We sought to report the clinical experience with extended total arch replacement for acute type A aortic dissection and to determine the factors that influence early mortality, late survival, and late reoperation. METHODS: Between December 1988 and August 1998, 70 patients underwent emergency graft replacement of both the ascending aorta and the total aortic arch for acute type A aortic dissection. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and open distal anastomosis. Concomitant procedures included aortic valve resuspension in 18 patients, composite graft replacement in 10 patients, and coronary artery bypass grafting in 5 patients. RESULTS: The early mortality rate was 16% (11 of 70 patients). Multivariable analysis showed that renal-mesenteric ischemia and coronary artery bypass grafting were independent determinants for early death. Survival rates at 3 and 5 years postoperatively, including the early deaths, were 75% +/- 5% and 73% +/- 6%, respectively. Multivariable analysis showed that renal-mesenteric ischemia and en bloc repair were independent determinants for late death. Freedom from reoperation was 91% +/- 4% and 77% +/- 8% at 3 and 5 years, respectively. Multivariable analysis showed that anastomotic leakage was the only significant determinant for late reoperation. CONCLUSIONS: Extended total arch replacement for acute type A aortic dissection could be justified in properly selected patients.

Changes in subjective sleepiness, subjective fatigue and nocturnal sleep after anaesthesia with propofol.

The purpose of this study was to clarify the changes in psycho-physiological functions after anaesthesia with propofol (PF). The subjects were seven healthy male volunteers and the duration of the anaesthesia was 1 h (14:00-15:00 h). The plasma concentration of PF immediately decreased after the anaesthesia. The subjective sleepiness and VAS (visual liner analogue scale) scores (i.e. effort to do something) increased significantly at 20 min after the anaesthesia. However, these changes were improved at 80 min after the anaesthesia. The sleep latency at the nocturnal sleep 8 h after the anaesthesia was prolonged significantly, but the other parameters including the distributions of stage 3 + 4 and the rapid eye movement 'REM' stage were not changed.

Anesthetic management of high-risk cardiac patients undergoing noncardiac surgery under the support of intraaortic balloon pump.

Patients with severely impaired left ventricular function, an uncorrectable coronary artery disease, and a recent myocardial infarction are at high risk of cardiac complications after major noncardiac surgery. We present two patients with extensive three-vessel coronary artery disease who underwent intraperitoneal surgery under the support of intraaortic balloon pump (IABP). In one patient, the IABP was inserted urgently because of the development of chest pain with significant ST depression on arrival in the operating room, and the other patient was managed with prophylactic IABP. There were no intraoperative or postoperative cardiac events in either patient. Thus, IABP should be considered in the perioperative management of patients with severe cardiac diseases.

[Anesthetic management using extracorporeal circulation of a patient with severe tracheal stenosis by thyroid cancer].

A 64-year-old male with tracheal stenosis by thyroid cancer was scheduled for the emergency management of airway maintenance and total thyroidectomy. Dyspnea and orthopnea appeared suddenly on the admission for operation. Cervical CT and bronchial fiberscope examination revealed the trachea oppressed at the frontal neck by thyroid tumor. The trachea diameter was nearly 5 mm at the narrowest part. Therefore it seemed to be of high risk of perform tracheal intubation and tracheostomy. Extracorporeal circulation was adopted for the respiratory management at anesthesia induction. At first, the femoral artery and vein were cannulated with local anesthesia for cardiopulmonary bypass (CPB). After confirming CPB pump working, intravenous anesthetic agents were infused. Thyroid tumor was partially resected and tracheostomy was done under CPB. After the tracheostomy, a spiral tracheal tube was inserted. Anesthesia was maintained with sevoflurane and managed with controlled ventilation. Thereafter operation and anesthesia were uneventful. After the operation, pleural bloody effusion was noticed. Blood in effusion seemed to be due to the heparinization in extracorporeal circulation. We conclude that anesthetic management with extracorporeal circulation is one of useful methods for managing severe tracheal stenosis.

Meningeal hemangiopericytoma metastatic to the heart.

We report for the first time the metastasis of intracranial hemangiopericytoma to the heart. In evaluating cardiac conditions, MRI provided useful information regarding the location and features of paracardiac tumors.

Unexpected extraction of a ventricular septal defect patch without an interventricular shunt.

We report the case of a mediastinocutaneous fistula, 13 years after the total correction of tetralogy of Fallot. During a fistula curettage operation, we unexpectedly extracted a ventricular septal defect patch. An interventricular shunt was not detected after the operation. The patient is well 3 years after the last operation.

[Experience of predeposit autologous blood transfusion and medication of recombinant human erythropoietin in pediatric open heart surgery].

To avoid using the homologous blood, 11 children between the age of 5 and 15 years donated autologous blood of 10 ml/kg of body weight (upper limit 400 ml) once a week for two weeks prior to elective open heart surgery. Five of 11 children received erythropoietin (100 U/kg of body weight) intravenously three times a week for two weeks. Only one patient experienced a mild donor reaction but no adverse effects occurred in erythropoietin therapy. In all the patients cardiac operations were able to be completed without homologous blood transfusion. Patients treated with erythropoietin were not anemic despite of preoperative donation although without erythropoietin therapy patients were mildly anemic. Our experience documents safety and effectiveness of predeposit autologous blood transfusion and erythropoietin therapy in pediatrics.

[Prediction of the maintenance dose of vecuronium for continuous infusion].

The purpose of this study is to examine how to predict the optimal maintenance dose of vecuronium for continuous infusion, knowing the recovery time from the block induced by the first bolus injection. All patients studied were undergoing surgical procedures and were anesthetized using thiopental, vecuronium, 50% nitrous oxide and 2% enflurane in oxygen. Mechanical twitch responses of adductor pollicis muscle caused by the stimulation of the ulnar nerve supramaximally were monitored. Vecuronium concentrations in the plasma were measured using high performance liquid chromatography. The experiments consisted of two phases. Phase 1.: To demonstrate the relationship between the recovery time (T0-T25) and the maintenance dose. Thirty patients were studied in this phase. A bolus injection was given as the first dose (1.5 mg.kg-1). During the recovery from the first block, recovery time (T1) was measured and the second dose (2 mg) was injected at the T25 (25% control twitch height). After waiting the recovery until the T25, the third dose (2 mg) was injected. The duration (T2) (min) between the second and the third injection was measured. The maintenance dose-recovery time curve was obtained. Y = 52.70.exp (-17.50 X) + 1224.53.exp (-224.27X), X = recovery time (min), Y = maintenance dose (mg.hr-1). Phase 2.: Thirty patients were studied in this phase. Patients received infusions after the bolus injection. The infusion rates were obtained from the maintenance dose-recovery time curve.(ABSTRACT TRUNCATED AT 250 WORDS)

[EEG analysis of the effectiveness of the benzodiazepine antagonist RO 15-1788 after diazepam sedation].

In ten volunteers given diazepam, a new diazepam antagonist RO 15-1788 was administered and the effectiveness of this drug was analyzed on EEG. EEG electrodes were attached at C3 and C4 taking right and left ear lobes as indifferent electrodes. EEG trend monitor used by us was equipped with a Fourier analyzer as well as a conventional EEG recorder. EEG was recorded first for about 15 minutes at rest with eyes closed, followed by intravenous injection of 10 mg diazepam. At the end of the test, the antagonist, RO 15-1788 0.5-0.8 mg was administered. Slow waves and alpha waves were frequently found at rest with eyes closed. After diazepam administration, however, power spectrum percent in rapid waves (13-17.5 Hz) mainly consisting of beta waves increased from 8.0 +/- 1.3% (mean +/- SE) to 19.9 +/- 2.2%. These changes were statistically significant (P less than 0.05). At the end of procedures RO 15-1788 was administered and percent of power spectrum in beta waves decreased from 17.4 +/- 2.8% to 9.5 +/- 1.5%. These changes were also statistically significant (P less than 0.05). The sedative effect of diazepam may be evaluated by monitoring these rapid waves since the antagonizing effect of RO 15-1788 is demonstrated on EEG.