[Traumatic aortic regurgitation: report of two surgical cases]

Two successful surgical cases with aortic regurgitation due to blunt trauma are reported. Case 1: A 48-year-old female was transferred to our hospital after a traffic accident. She was intubated and mechanically ventilated. Twelve days later, echocardiography demonstrated massive aortic regurgitation. The next day, aortic valve replacement was performed using a 21 mm SJM mechanical valve. The central part of the non-coronary cusp was torn and perforated 15 mm long. She is in good condition three years after surgery. Case 2: A 57-year-old male was transferred to the nearest hospital because he was involved in a snowslide accident. A month after the injury, catheterization showed massive aortic regurgitation and pulmonary hypertension. An aortotomy revealed that the intima around the right coronary ostium was completely torn. A perforation with a diameter of 3 mm was also observed on the right coronary cusp. After coronary cusps were excised, interrupted mattress sutures buttressed with pledgets were passed through the aortic wall at the distal level of the intimal laceration and then to the aortic annulus. A 25 mm SJM prosthetic valve was seated at the aortic ring. As the right coronary ostium was included in the plicated aortic wall, aortocoronary bypass was constructed using the great saphenous vein. He is doing well 14 months after surgery. Aortic regurgitation due to blunt trauma is rare and difficult to diagnose. Sometimes cardiac failure progresses rapidly. Therefore, urgent surgery is recommended as soon as the diagnosis is confirmed.

[Cerebral embolism due to left atrial ball thrombus without mitral stenosis--usefulness of the transesophageal echocardiography for the diagnosis]

We reported two cases of cerebral embolism associated with atrial fibrillation. Left atrial ball thrombus without mitral stenosis was diagnosed by the transesophageal echocardiography, followed by successful removal. Left atrial ball thrombus has a risk for lethal complications, and a high incidence of systemic embolism even during anticoagulation therapy. An immediate surgical treatment is needed. The transthoracic echocardiography is not useful in diagnosis for left atrial ball thrombus. It is important to examine left atrial ball thrombus by the transesophageal echocardiography in patients with cerebral embolism associated with atrial fibrillation.

[A survival case of intraoperative pulmonary embolism diagnosed early by transesophageal echocardiography]

An otherwise healthy 36-year-old housewife was diagnosed with advanced cancer of the stomach 5 months after her third parturition. Surgery was performed with the patient under total intravenous anesthesia combined with continuous epidural anesthesia. The course of anesthesia and the operative course were uneventful until the abdominal skin was sutured, when unexplained severe circulatory collapse developed. A widely dissociated PETCO2- PaCO2 suggested pulmonary embolism, and the findings of transesophageal echocardiography corroborated the diagnosis. Infusion of 480,000 units of urokinase in 30 minutes was immediately started via a Swan-Ganz catheter, and intravenous heparin 10,000 units in 24 hours, was administrated continuously. The pulmonary circulation was restored 30 minutes after the start of therapy, resulting in rapid recovery of the patient's systemic circulatory and acid-base status. The patient was safely extubated 19 hours postoperatively.

[Epidural anesthesia for herniorrhaphy in a patient with severe dilated cardiomyopathy (DCM) under pimobendan control]

A 60-year-old man with severe DCM was scheduled for a herniorrhaphy under epidural anesthesia using fentanyl. Three months prior to operation, the patient suffered heart failure associated with life-threatening ventricular arrhythmia. The former was successfully treated with pimobendan as the main constituent of medication, but the latter was not responsive to various antiarrhythmic drugs with the exception of aprindine. On the day of operation and for two days postoperatively, pimobendan was administered daily. A sudden drop in systemic blood pressure and central venous pressure (CVP) during anesthesia, as well as the tendency to hypotensive status in the postoperative period were well regulated with continuous infusion of dopamine and dobutamine via CVP catheter probably due to the effect of up-regulation of pimobendan, together with adjustment of the volume of intravenous fluids. No dangerous ventricular arrhythmia were observed. Thereafter the patient made uneventful progress and was discharged on the 8th postoperative day.

Effects of partial blood replacement with pyridoxalated hemoglobin polyoxyethylene conjugate solution on transient cerebral ischemia in gerbil

Blood components were reported to be aggravating factors of ischemic cerebral injury. We previously reported that a partial blood replacement with Fluosol DA reduced ischemic neuronal injury. The purpose of this study is to elucidate whether pyridoxalated hemoglobin polyoxyethylene conjugate solution (PHP) exerts neuro-projective effects against cerebral ischemia.

METHODS

38 adult male gerbils were divided into 4 groups, such as normal group without ischemia or treatment, PHP group undergoing an exchanging blood transfusion with 5.0 ml PHP, ischemia group undergoing 5-min forebrain ischemia, and PHP-ischemia group with 5.0 ml PHP partial blood replacement prior to 5-min forebrain ischemia. Cerebral injury was assessed 7 days after treatment. In another group, effects of PHP on blood nitric oxide (NO) and cerebral blood flow (CBF) were studied.

RESULTS

CA1 cell density was 140-2/mm in normal group and 142-5/mm in PHP group. The cell density was markedly reduced to 38-13 in ischemia group. The cell density was further reduced 27-10/mm in PHP-ischemia group. PHP was found to have a potent NO scavenger action and reduce CBF.

CONCLUSION

Partial blood replacement with PHP prior to ischemia may cause cerebral vasoconstriction due to NO scavenger action and may worsen ischemic injury.

[Anesthetic problems in a 480 g infant for ventriculo-peritoneal shunt surgery]

A 480 g, 38-day-old female infant underwent ventriculo-peritoneal shunt surgery for hydrocephalus after intra-ventricular hemorrhage. The patient was born at a gestational age of 25 weeks and 5 days, weighing 600 g, as one of twins by a cesarean section. Although respiratory distress syndrome developed, it was relieved with surfactant. The esophagus was easily perforated by a gastric tube. At the age of 7 days, PDA was closed conservatively with indomethacin. Anesthesia was induced and maintained with fentanyl (induction dose 4 micrograms.kg-1, total dose 6 micrograms.kg-1) and vecuronium. Ventilation was controlled with oxygen and air (FIO2 0.21-0.25). The main problems encountered by anesthetists in the perioperative period were; fluid management (hyperkalemia, hyponatremia, infusion volume), bradycardia due to increased intracranial pressure, body temperature control (hypothermia), and transport to the operating room. In anesthesia for extremely low birth weight (extremely premature) infants, utmost care and proficient procedure are required because of their immaturity, fragility and smallness.

[Unexpected intraoperative respiratory distress; an infant who developed tracheomalacia and fatal aortoesophageal fistula due to unrecognized vascular ring]

Vascular rings cause respiratory distress and dysphasia by tracheoesophageal compression. We present a case of tracheomalasia and fatal aortoesophageal fistula due to unrecognized vascular ring. A 3-month-old (7.3 kg) boy underwent V-P shunt operation under sevoflurane anesthesia. The trachea was intubated easily using vecuronium with a relatively large-size tube with a diameter of 4.5 mm, because of leakage. Gastric intubation was difficult. During scrubbing of the head, an asthma-like respiratory distress suddenly occurred. The condition responded poorly to ventilatory support and pharmacological interventions. Although intraoperative fiberscopy through the tracheal tube and chest X-ray showed no tracheobroncheal abnormality, postoperative fiberscopy revealed a tracheomalacia. Adequate ventilation was possible only when the tip of the tracheal tube was located between the stenotic part and the tracheal carina. On the 9th postoperative day, during respiratory management with a tracheal tube, fatal esophageal hemorrhage broke out. Postmortern examination revealed a double aortic arch with tracheal stenosis and aortoesophageal fistula. The nasogastric tube may have led to fistula formation by compression of the esophageal wall against an anomalous vessel. When anesthetists encounter an infantile respiratory distress, even in perioperative period, vascular rings should be taken into consideration.

[Tetralogy of Fallot with a restrictive ventricular septal defect caused by a membranous flap]

A 5-year-old boy who had typical tetralogy of Fallot (TOF) with mild cyanosis was referred to us. Preoperative echocardiogram revealed that in addition to the TOF morphology, an abnormal piece of tissue attached to the right side of the ventricular septum was floating and obstructing flow through the ventricular septal defect (VSD) in systole. Preoperative cardiac catheterization showed suprasystemic right ventricular pressure with a gradient of 60 mmHg between the right ventricle and the aorta, and a right ventriculogram demonstrated a narrow radiolucent structure beneath the aortic valve in the right ventricle. During surgery a fibrous membranous tissue, with no relation to the tricuspid valve, was found to extend from the edge of the VSD to the aortic valve and to partially occlude the defect. This tissue was used as a suture anchorage for patch closure of the defect. Preoperative echocardiography is useful to detect such flaps and early surgical correction should be done to prevent right ventricular failure resulting from right ventricular pressure overload.

[Successful primary correction for tetralogy of Fallot associated with total anomalous pulmonary venous drainage (type Ia)]

The surgical correction was performed successfully in a 3-year-old girl with tetralogy of Fallot associated with total anomalous pulmonary venous drainage (type Ia). The preoperative cardiac catheterization and angiography showed high systolic pulmonary artery pressure (58 mmHg) and small left ventricular volume (54% of normal). The early postoperative course was stormy because of the unstable circulatory state. During the early postoperative period, we estimated the volume of left ventricle by 2 D echocardiography. A significant increase of the volume was observed on the 8th postoperative day, when her circulatory state became stable. The cardiac catheterization before discharge revealed Pp/Ps of 0.38 and normal LV volume. We conclude that primary repair should be done for this combined cardiac anomaly, even if small left ventricle and pulmonary hypertension is present.

[The protective effect and problem of retrograde cerebral perfusion]

In order to study the protective effect and problem of retrograde perfusion (RCP), cerebral hemodynamics and cerebral metabolism were evaluated in fourteen pigs weighing 25-30 kg. Intracranial pressure, carotid arterial flow and pressure, and internal jugular venous pressure as cerebral hemodynamics; pyruvate, lactate, and oxygen consumption as cerebral metabolism; and brain temperature were measured. The animal was cooled to electrical cerebral silence on electroencephalogram under cardiopulmonary bypass. Then, animals were divided into three groups: group I (n = 4); circulatory arrest; group II (n = 3); RCP through superior vena cava (SVC); group III (n = 7); RCP through bilateral internal jugular vein (IJV). Retrograde perfusion flow was regulated to maintain the SVC pressure or IJV pressure of 30 mmHg, for 90 minutes. The variations in brain temperature were least in group III. As perfusion flow increased, intracranial pressure, and inferior vena cava (IVC) pressure increased. But, cerebral perfusion pressure, which was calculated from the difference of intracranial arteriovenous pressure, did not increase and, SVC pressure and returned blood flow through the aorta did not increase in group III. In group II, there was no significant relation between pump flow, SVC pressure, and intracranial pressure, but SVC pressure had a positive correlation with the pressure gradient of SVC-IJV. The uptake of cerebral lactate, cerebral pyruvate, and lactate-pyruvate ratio, and cerebral oxygen consumption were superior in group III than other groups. In conclusion, RCP through IJV was advantageous to maintain hypothermia and aerobic metabolism of the brain during systemic hypothermic circulatory arrest.(ABSTRACT TRUNCATED AT 250 WORDS)

[The study on cerebral hemodynamics during selective cerebral perfusion]

This study was undertaken to clarify characterization on cerebral hemodynamics during deep hypothermic selective perfusion (SCP) in 18 pigs. Besides, the changes on cerebral hemodynamics were investigated with obstruction to venous drainage due to the clamp of superior vena cava (SVC) cannula. For SCP, blood was infused into aortic arch with the clamp of descending aorta, during 90 minutes at 20 degrees C. We measured regional cerebral blood flow (CBF), intracranial pressure (ICP), and carotid arterial flow (CAF), and carotid arterial pressure. The carotid arterial pressure as perfusion pressure was not significantly correlated with CAF, CBF and ICP. Although CAF increased as pump flow rate increased, the relationship between pump flow and CBF was not significant. Moreover, SVC pressure showed a tendency to increase, as CAF increased. Both ICP and internal jugular vein pressure (IJVP) were significantly (p < 0.01) increase, and CAF was significantly (p < 0.05) decrease with the clamp of SVC cannula. On the other hand, both ICP and IJVP were significantly decrease, and both CAF and CBF were increase, without unclamp of SVC cannula. The results suggest that cerebral autoregulation is intact during deep hypothermic SCP, and hyperperfusion cause the increase of shunt flow in extracranial area, and besides, the increase of ICP with obstruction to venous drainage cause decrease in cerebral blood flow.

[Flow characteristics and responses to vasoactive drugs in canine gastroepiploic artery]

We studied flow characteristics and response to norepinephrine, Chlorpromazine and gastrin in 22 canine gastroepiploic artery (GEA) recirculation model. The GEA flow was obtained by a drip for a minute, opening the end of pedicle GEA. Furthermore, aortic flow and celiac arterial flow were measured by magnetic flow probe. The administration of chlorpromazine, vagostigumine, and gastrin induced a increase in both celiac arterial flow and pedicle GEA graft flow. Especially, the administration of gastrin induced significant increase in GEA flow and celiac arterial flow. Furthermore, adding norepinephrine step-wisely, the GEA flow increased remarkably, in spite of decrease of celiac arterial flow. This response was caused from difference in vascular resistance among celiac arterial branches. Therefore, the pedicle GEA graft has homogenous response as same as intact GEA that perfuses stomach, because its flow was affected by adrenergic and parasympathetic agent, alpha-blocker and gastric hormone.

[Anesthetic management of palliative surgery for hypoplastic left heart syndrome--a case report]

The first patient with hypoplastic left heart syndrome who was treated successfully by palliative surgery at our hospital is reported. Soon after birth, the female infant showed tachypnea and cyanosis, and was transferred to our institution under a presumptive diagnosis of HLHS. Although cardiologists confirmed the diagnosis by two-dimensional echocardiography, the surgery was postponed for one month because it was possible to keep the ductus arteriosus open without PGE1, and the patient showed no deterioration. Fortunately, an abnormal vessel connecting the left atrium with the superior vena cava relieved severe pulmonary venous congestion by diverting the blood flow. During the pre-CPB period, frequent adjustment of the oxygen concentration and ventilator setting was required in order to keep the blood gas values optimal compared with the values before surgery. After CPB, adequate blood pressure using catecholamines and hyperventilation with 100% oxygen was necessary to increase the pulmonary blood flow and to decrease the pulmonary vascular resistance. It is concluded that preservation of the balance between PVR and SVR during the perioperative period, and adequate systemic arterial pressure after CPB are crucial. Furthermore, constant and intense observation is mandatory to facilitate immediate treatment even after surgery in case of systemic hypoperfusion due to excessive pulmonary blood flow.

Scopolamine patch reduces postoperative emesis in paediatric patients following strabismus surgery

Scopolamine patch was evaluated for the prevention of postoperative emesis in 50 children undergoing strabismus surgery. All subjects were premedicated, with none receiving narcotic premedicants. Anaesthesia included controlled ventilation with the use of muscle relaxants, atropine, and halothane. Before operation, the subjects were randomly assigned to one of two groups: a treatment group received a scopolamine patch at a dose of either 0.75 mg or 0.375 mg, and a control group received no patch. Both the incidence and frequency of vomiting in the scopolamine-treated group were significantly (P less than 0.05) lower than in the control group.

Accidental extubations during respiratory management in a children’s hospital

An investigation was conducted on the frequency of accidental extubations at Shizuoka Children's Hospital during the past 12 years. The study was performed on 150 randomly selected patients who received respiratory support for more than 24 hr. Fifteen accidental extubations occurred in 9 patients. Most of them (87%) occurred in the neonatal intensive care unit (NICU), and the rate was 1 per 54 days of intubation. The time at which these accidents happened varied, although they were more common during the day-time. The reasons of accidental extubation could not be specified in two-thirds of the cases. It became clear that more immature babies were more likely to suffer accidental extubation, perhaps reflecting the fact that most of the immature babies in the NICU were intubated orally, and that a larger proportion of them required a longer period of respiratory support. Therefore, early weaning from respiratory support is recommended if it is possible. In conclusion, increased surveillance and more secure methods of taping of endotracheal tubes are crucial for preventing life-threatening accidental extubations during respiratory support.

Diagnosis of submucosal tumor by injecting a water soluble contrast medium: development pattern and growing of tumors

With the application of our endoscopical method of contrasted X-ray imaging, gastric submucosal tumors were studied with chief regards to their modes of growing up and patterns of development. It has become known that, of extra-gastric developing tumors, larger ones tend to show Pattern IVa and smaller ones Pattern IVb. Generally, the tumors showed a tendency of becoming larger in older patients. Periodical checking disclosed about 15% of the tumors growing larger with the lapse of time. It has been surmised that as tumors grow up, their development possibly turns from intra-gastric to intramural and mingled in pattern. Their modes of growing could be classified as follows: Abruptly growing large at a certain time and then remaining without notable changes, step-by-step enlarging, and gradually growing up straight forwardly with years.

Cytological diagnosis of leiomyogenic tumors of the stomach

The cytological findings in 7 cases of leiomyoma and 4 cases of leiomyosarcoma can be summarized as follows: For differential diagnosis of these lesions, in comparison with leiomyoma cells, leiomyosarcoma cells were found to have 1) increased minor axis diameters of the nuclei and nuclear anisokaryosis, 2) dark nuclear staining, 3) enlarged and darkly stained chromocenters, 4) dark staining and thickening of the nuclear rim, 5) enlargement of nuclear clear areas, 6) increased numbers of oval nuclei and greater pleomorphism, 7) an increase in size and number of the nucleoli, 8) a strong tendency for cell atypism, such as anisocytosis and pleomorphism. In the light of these findings, it is believed that differential diagnosis is indeed possible.