[Surgical relief of airway obstruction from a double aortic arch associated with corrected transposition of the great arteries, pulmonary atresia and bilateral patent ductus arteriosus in a neonate]

A rare 20-day-old male with double aortic arch, corrected transposition of the great arteries (cTGA), pulmonary atresia and bilateral patent ductus arteriosus (PDA) was transported to our institute because of severe respiratory dysfunction and cyanosis. The patient had been already intubated and ventilated on respirator. A echocardiography and cine-angiography demonstrated that the both sides aortic arch had almost identical sizes, originating common carotid arteries and subclavian arteries and PDAs respectively, and the descending aorta located on the left side of the mid-line. At the first surgery, the distal of the right aortic arch was divided just proximal to the descending aorta after complete tissue dissection around the arch. The divided right sided aortic arch was mobilized from posterior to anterior aspect of the bronchus. Then the right subclavian artery was divided and an original Blalock-Taussig shunt was employed. The right sided PDA was ligated. After the first surgery, respiratory dysfunction lasted for weeks mainly because of the PGE1 dependent left sided PDA. At the second surgery, left sided modified Blalock-Taussig shunt was constructed and the left sided PDA was divided. These procedures resulted in stable respiratory status and oxygen saturation. The patient was extubated three days later and now in satisfactory clinical condition.

[Surgical treatment of double outlet left ventricle]

Double outlet left ventricle (DOLV) is an uncommon congenital cardiac defect which was first reported by Sakakibara and associates. We studied anatomical aspects relevant to surgical repair in our 4 cases and additional 28 cases which had been reported on the literatures. The locations of ventricular septal defect (VSD) were subaortic in 20 cases, subpulmonary in 7, doubly-committed in 2 and unknown in 2. The positions of the aorta relative to the pulmonary artery were right or left anterior oblique in 11 cases, right or left side-by-side in 9, right or left posterior oblique in 10 and unknown in 3. The definitive surgery included Rastelli type operation in 18 cases, right ventricular outflow tract repair with closure of VSD in 6, intraventricular conduit repair in 4 and Fontan type operation in 4. In regard to the selection of the procedure, the size of right ventricle, the presence of pulmonary stenosis, the location of VSD and the relationship of the great arteries are very important. Although most of the patients underwent the Rastelli type operation, the right ventricular outflow tract reconstruction or intraventricular conduit repair could be adopted particularly in patients with posterior oblique position of the aorta relative to the pulmonary artery or subpulmonary VSD.

Small left coronary arteries after arterial switch operation for complete transposition

BACKGROUND

Myocardial perfusion is not completely normal and ventricular function is depressed in some patients after the arterial switch operation. The basic mechanism has not yet been defined totally.

METHODS

The diameters of the right, left main trunk, anterior descending, and circumflex coronary arteries were measured by computer-assisted densitometry at 8 to 86 months (mean, 47.5 months) after the arterial switch operation in 86 patients.

RESULTS

The Z scores, compared with control, were +2.0 +/- 0.3, -1.8 +/- 0.3, and -1.5 +/- 0.3 for the right, left anterior descending, and circumflex coronary arteries, respectively. The Z score for the total cross-sectional area of the three vessels was -1.5 +/- 0.3. These parameters did not correlate with left ventricular ejection fraction.

CONCLUSIONS

At the midterm follow-up after the arterial switch operation for complete transposition of the great arteries, the left coronary arteries are small. A careful follow-up study is mandatory to clarify the clinical significance of this finding.

Ventricular hypertrophy as a risk factor in ventricular septation for double-inlet left ventricle

BACKGROUND

Ventricular septation is an option for surgical correlation of double-inlet or common-inlet left ventricle. However, the surgical risk factors of ventricular septation remain unknown.

METHODS

Twenty-three patients with double-inlet or common-inlet left ventricle underwent ventricular septation. Preoperative data were compared between the survivors (n = 18) and the nonsurvivors (n = 5) to assess surgical risk factors.

RESULTS

There were two early deaths (9.5%) and three late deaths (14.3%). Nonsurvivors of ventricular septation were significantly older at the time of operation (14.0 +/- 6.0 versus 7.0 +/- 5.4 years; p < 0.05) and had greater left ventricular mass (383% +/- 100% versus 206% +/- 57% of normal predicted value; p < 0.005) and greater left ventricular mass to left ventricular end-diastolic volume ratio (1.84% +/- 1.18% versus 0.77% +/- 0.17%/% of normal predicted value; p < 0.005). Univariate logistic regression analysis also revealed age at operation (p < 0.05) and mass/end-diastolic volume ratio (p < 0.05) as significant risk factors for death after operation. Multivariate regression analysis revealed that age at operation positively influenced increased mass/end-diastolic volume ratio (p < 0.001). These findings indicated that ventricular hypertrophy was one of the risk factors for ventricular septation, which had a tendency to progress with age.

CONCLUSIONS

Early operation before progression of ventricular hypertrophy is recommended in patients with double-inlet or common-inlet left ventricle who have suitable anatomy for the ventricular septation procedure.

[A successful mitral valve replacement for a 13-year-old girl with mitral stenosis and pulmonary hypertension after renal transplantation]

Mitral valve replacement was successfully performed in a 13-year-old girl due to severely calcified mitral valve stenosis and pulmonary hypertension who had undergone renal transplantation from her father at the age of 8 years old. Although, percutaneous transluminal mitral commissurotomy had been performed for four times until January 1996, severe mitral stenosis could be relieved and she was transported to our hospital in emergency for respiratory failure caused by pulmonary edema. Then we decided to perform mitral valve replacement. The operation was done successfully using trans-septal superior approach with SJMHP 19 mmM. the blood cyclosporin levels were monitored and controlled within normal limits. This is the first successful case of pediatric open heart surgery after renal transplantation to our knowledge.

Fate of trileaflet equine pericardial extracardiac conduit used for the correction of anomalies having pulmonic ventricle-pulmonary arterial discontinuity

BACKGROUND

External conduits used for the repair of congenital heart diseases having discontinuity between the pulmonic ventricle and the pulmonary artery still carries a high risk of reoperation. Between June 1983 and June 1992, handmade equine pericardial conduit with fabricated trileaflet valve had been the conduit of choice in our institute. The aim of this study is to clarify the temporal sequence of conduit obstruction in this material and to formulate the optimal surgical strategies for this disease entity.

METHODS

One hundred forty-three patients have undergone extracardiac conduit repair using this conduit. Postoperative catheterization performed within 2 months showed pulmonary to systemic ventricular systolic pressure ratio of 0.57 +/- 0.17 with the pressure gradient between pulmonic ventricle and pulmonary artery of 21.1 +/- 17.2 mm Hg. In 63 patients among the survivors, a series of Doppler two-dimensional echocardiographic images could be clearly obtained.

RESULTS

Moderate-to-severe degree of pulmonary insufficiency represented only 3.2% of all cases within 3 months, which rapidly increased to 14.3% at 1 to 3 years and 32.8% at 3 to 5 years. However, the rate of increase of pulmonary insufficiency diminished beyond 5 years with 34.9% at 5 to 7 years and 40.0% at 7 to 9 years. Estimated pressure gradient calculated by Bernoulli's equation applied in the same patient subset was 4.1 +/- 7.9 mm Hg within 3 months, which progressively increased to 7.1 +/- 11.8 mm Hg at 1 to 3 years, 21.0 +/- 24.0 mm Hg at 3 to 5 years, 40.2 +/- 25.9 mm Hg at 5 to 7 years, and 71.3 +/- 34.0 mm Hg at 7 to 9 years. Among patients with a pressure gradient across the conduit of more than 40 mm Hg at follow-up catheterization, the primary cause of the obstruction was attributed to degeneration of the valve in 7 patients, whereas sternal compression was strongly suspected as the primary cause in the other 8 patients. Intimal peel was not obvious in the excised specimens.

CONCLUSIONS

Degeneration of the valve in the equine pericardial conduit became prominent at 3 to 5 years after the operation, whereas the pressure gradient across the conduit continued to progress thereafter. A thick and hardened valve from degeneration and varying degrees of external compression by the sternum were delineated at the site of stenosis.

An automatic flow controller for a centrifugal blood pump

To regulate the perfusion flow rate of a centrifugal blood pump, a microcomputer controller was developed. The computer monitored the flow rate of the pump with an electromagnetic flowmeter or an ultrasonic pulse Doppler flowmeter, rotational speed of the pump, aortic pressure, and the amount of blood in a reservoir. A discrete integral controller with a control interval of 1 s was adopted for the controller. For the safety of the control system, we added functions for detecting a clamp on the tubing, a dislocation of the flow sensor, or an inverse direction of the flow sensor. During a standby period, the computer calculated the rotational speed from aortic pressure to minimize the forward or the backward flow at the start of the pump perfusion. The automatic flow controller was used on 5 patients during cardiac operations and maintained the flow rate within +/-6% of the set point.

[A case of porencephaly with mirror movements: pathophysiological investigation by using long-latency long-loop reflex and dipole tracing method]

We report a 42-year-old left-handed woman with congenital right hemiparesis and bilateral mirror movements in the hands. She had a porencephaly of the left hemisphere and the brain MRI demonstrated cortical and subcortical defect of the left hemisphere from Brodmann's area 6 to 40 including the left motor cortex. By electrical stimulation of the left median nerve at the wrist, N20 of the somatosensory evoked potential was recorded in the right postcentral gyrus by using the dipole tracing method. Long-loop reflexes from the bilateral thenar muscles were recorded and their latencies were almost the same. The stimulation of the right median nerve did not evoke N20, nor long-loop reflex. These electrophysiological findings suggest that the reorganization of the motor system made the right motor cortex to innervate bilateral hands, and caused bilateral mirror movements. In other words, the mirror movements managed to relieve the paralysis of the right hand though the damage of the left motor cortex was present. In the previous literature we are able to find hypotheses regarding the mechanism of mirror movements in congenital hemiparesis. Here we discussed about the reorganization of the motor system in the damaged brain.

A case of Turner's syndrome associated with partial anomalous pulmonary venous return complicated by dissecting aortic aneurysm and aortic regurgitation

We report a successful surgical case with Turner's syndrome associated with partial anomalous pulmonary venous return (PAPVR) complicated by aortic dissection and aortic regurgitation without coarctation of the aorta. The patient, a 30-year-old woman, is of a short stature who was diagnosed with Turner's syndrome at the age of 12. She has suffered from dyspnea and edema of the legs since a year ago and was admitted to our hospital in June 1994 as echocardiography revealed rapid dilatation of ascending aorta and aortic regurgitation. A chest X-ray showed cardiothoracic ratio of 63% and transesophageal echocardiogram revealed that ascending aortic diameter was extended up to 60 mm at its maximum and that it was possible to distinguish true lumen from false lumen. The aortic arch was found to be normal. Also revealed by cardiac catheterization was drainage of the left upper pulmonary vein to the innominate vein. The L-R shunt ratio was 2.2. The surgery was performed by the Bentall method. The composite graft with a 21 mm St. Jude Medical prosthetic heart valve placed on the annulus of aortic valve. The ostiums of the coronary arteries were directly anastomosed to the composite graft with Carrel patch. After declamp of the aorta, the left pulmonary vein was directly anastomosed to the left atrial appendage without causing stenosis. The postoperative course was uneventful, and the cineangiogram after surgery demonstrated successful repair. Reports of cases of Turner's syndrome like this are sparse.

Time course of endothelin-1 and nitrate anion levels after cardiopulmonary bypass in congenital heart defects

BACKGROUND

The endothelium-derived vasoconstrictor endothelin-1 (ET-1) may be involved in pulmonary hypertension (PH), but production of the endothelium-derived vasodilator nitric oxide (NO) after cardiopulmonary bypass (CPB) in congenital heart disease is unclear.

METHODS

Twenty patients (age, 4 months to 12 years) were divided into three groups: severe PH (mean pulmonary-to-systemic arterial pressure ratio > 0.5) and high pulmonary flow (n = 8), mild PH (mean pulmonary-to-systemic arterial pressure ratio < 0.35) and high pulmonary flow (n = 6), and no PH and low pulmonary flow (n = 6). The mean pulmonary-to-systemic arterial pressure ratio was calculated and blood samples were taken, and NO3-, an NO metabolite, was measured.

RESULTS

Levels of ET-1 in the group with severe PH and high pulmonary flow were higher than in the other groups until 6 hours after CPB, and NO3- was not changed significantly in the group with severe PH and high pulmonary flow and or the group with mild PH and high pulmonary flow during CPB. Endothelin-1 in the group with no PH and low pulmonary flow was higher than in the group with mild PH and high pulmonary flow after CPB, and NO3- in the group with no PH and low pulmonary flow significantly decreased after CPB. A positive correlation was obtained between mean pulmonary-to-systemic arterial pressure ratio and ET-1 (r = 0.742 before CPB; r = 0.689 after CPB).

CONCLUSIONS

Imbalance between increased ET-1 and constant NO after CPB in the group with severe PH and high pulmonary flow could contribute to dominant effects of ET-1, which may injure the lung. The increased ET-1 and the decreased NO after CPB in the group with no PH and low pulmonary flow may induce a mechanism of protective vasoconstriction against an acute increase in pulmonary flow.

Modified Fontan procedure in ninety-nine cases of atrioventricular valve regurgitation

Between January 1985 and August 1995, among 242 patients who underwent a modified Fontan procedure, 99 had atrioventricular valve regurgitation ranging in degree from 1 to 4, for which concomitant repair of the atrioventricular valve regurgitation was done in the majority of cases. In all but 4 cases the atrioventricular valve was repaired mainly by circular annuloplasty and valve replacement was not done in any case. Although the hospital mortality rate was significantly higher in cases with atrioventricular valve regurgitation (12/99, 12%) than in cases without (4/143, 3%; p < 0.0037, chi 2 test), actuarial survival in atrioventricular valve regurgitation was 84% for years 5 through 10. The degree of atrioventricular valve regurgitation before operation was 1.6 +/- 0.7 on average: in 49 cases with higher than grade 2 regurgitation before operation there was a significant decrease to 0.4 +/- 0.49 (p < 0.0001) after operation in short-term survivors. Patients with atrioventricular valve regurgitation can be treated with reasonable risk, provided proper repair of the valve is done. Circular annuloplasty is a simple and uniformly effective method to control regurgitation even in cases of common atrioventricular valve.

A study on the evaluation of masticatory ability in osseointegrated implants applied to lower molar region

Masticatory function was investigated in 7 subjects (5 women and 2 men) with unilateral OIB in their lower molar region. Masticatory movement and myoelectric discharge were analyzed. To examine occlusal contact, the closely occlusal contact area and occluding forces were investigated. The results from the OIB side were compared with the ones from the opposite side. In all subjects, there were no significant differences in the parameters of mandibular movement between chewing the test foods on the OIB side and chewing them on the opposite side. In 6 out of 7 subjects, the closely occlusal area of the interocclusal space differed by less than 1.0 mm between the OIB side and the opposite side in the molar region, and the occluding forces between them were similar. In 6 out of 7 subjects, the masticatory sensations were also similar between the two sides. There were no significant differences between the OIB side and the opposite side in the parameters of mandibular movement, the condition of occlusal contact and the sensation of mastication in patients who were treated with unilateral OIB in the lower molar region. The data seem to suggest that there is little difference between the masticatory ability of OIB and that of natural dentition.

[Calcified EPTFE vascular prosthesis in the Blalock-Taussig shunt after 4 years of implantation: a case report]

A boy was born with asplenia, complete endocardial cushion defect, pulmonary atresia and transposition of great vessels. Modified Blalock-Taussig (BT) shunt procedure to the right pulmonary artery was performed using an expanded polytetrafluoroethylene (EPTFE) vascular graft three days after born in 1990. At one year old, left BT-shunt procedure was also performed. At four years old (1994), bi-directional Glenn procedure was performed. At that time, a piece of the EPTFE graft in the BT-shunt at the pulmonary anastomosis, was removed and observed macroscopically and microscopically. It was patent with a neointima and thrombi. Microscopically, multiple calcified legions and many macrophages were found in the graft wall. Thrombi on the graft lumen, which were suspected to be formed different occasions, were observed. A thin neointima with an endothelial cell layer near the anastomosis was remarkable. To our knowledge, this is the first report of such calcified lesions in the EPTFE vascular graft wall within 4 years in the BT-shunt position in an infant.

[Coagulation disorders as early predictor of brain injury]

To identify early prognostic value of brain injury, a comparison was made between computerized tomography (CT) findings, coagulation abnormalities, and clinical features in 51 patients with closed head injury. The patients were divided into three groups according to their plasma level of fibrin-fibrinogen degradation product (FDP): normal group (FDP 10 micrograms/ml or less) in 20 patients; moderately abnormal group (FDP 10-40 micrograms/ml) in 15 patients; and highly abnormal group (FDP 40 micrograms/ ml or more) in 16 patients. Cases with a fatal clinical course were mostly associated with very high FDP level. Mortality rate in the highly abnormal group was 44% and 7% in the moderately abnormal group were dead cases, while no cases in the normal group turned out poor outcome. Injury severity, as assessed by Glasgow Coma Scale (GCS) score, correlated with the increase of plasma FDP level. Although severe head injury (GCS 8 or less) was found in 44% of the highly abnormal group and 13% of the moderately abnormal group, normal group only had one case (5%). Very high FDP concentrations were found to be associated with combined hemorrhagic lesions and mass effect on CT scan, but not with a specific localization of brain damage. In summary, the evaluation of coagulation and fibrinolytic function in patients following closed head injury might have both diagnostic and prognostic value.

[Transverse lesion of the spinal cord due to mucormycosis in an AML patient]

A 54 year old man complained exertional dyspnea and palpitation since November 1989. As he was diagnosed with marked anemia, leukocytosis and thrombocytopenia by his work place doctor, he was admitted to our hospital. Acute myelogenous leukemia was diagnosed based on laboratory findings. BHAC-DMP, BHAC-MEP and A triple V therapies were only partially effective. Fine nodular shadows in all lung fields and a semicircular mass in the right lower lobe next to the thoracic vertebra were evident on the chest X-P since the end of March 1990. He was treated with antibiotics and amphotericin B but the abnormal lung shadows did not disappear. He had sudden onset of paraplegia and loss of all sensation below Th6 on May 1. Aparavertebral mass in the right lower lobe was detected by CT and MRI, for which radiotherapy was performed but without improvement. He died of respiratory failure on May 12. Autopsy showed that the semicircular paravertebral mass continued to the main pulmonary vein and epidural area of the thoracic cord (Th6-8). Microscopically, mucormycosis was found. Necrosis due to mucor embolism was found in the thoracic cord. It is usually difficult to diagnose mucormycosis in immunocompromised patients while they are alive. It is important to suspect mucormycosis if any infarction symptoms or infections resistant to antibiotics develop in immunocompromised patients.

[Continuous systemic venous oxygen saturation monitoring immediately after Fontan procedure]

Changes in cardiac output (CO), systemic venous oxygen saturation (SvO2), systemic oxygen consumption, and urinary output immediately after Fontan procedure were measured in 10 patients at the intensive unit (ICU) to assess the effects of aorusal from anesthesia, hypothermic management, and respiratory condition. The measurements were taken at the following phases; phase A in deep sedation under hypothermia (33-35 degrees C rectal temperature) and controlled ventilation; phase B in mild sedation under normothermia and controlled ventilation; phase C when awake under normothermia and assisted ventilation; phase D when awake under assisted ventilation; phase D when awake under normothermia immediately after extubation; and phase E 24 hours after extubation. Oxygen delivery (O2 Del.) and fractional oxygen fractions were calculated in each phase. Two patients whose SvO2 values were below 55% during the postoperative course needed reoperation for atrioventricular valve regurgitation in one case for PV stenosis in the other case. CO increased significantly (p < 0.05) after extubation (phase D), compared with that of controlled ventilation (phase B). Under hypothermia (phase A), urinary output was relatively higher with lower CO. There was a significant correlation between SvO2 and CO (R = 0.61) in phase A, however there was no correlation in phase E. Fractional oxygen extraction in phase A was significantly lower than in phase B. In conclusion, the continuous SvO2 measurements reflected real-time changes in cardiac output in the immediate post-Fontan patients. Induced hypothermia was beneficial in increasing urinary output presumably through the correction of maldistribution of cardiac output in post-Fontant patients. Arousal from anesthesia and spontaneous ventilation seemed advantageous for increasing cardiac output, hence, early extubation should be encouraged in the management of post-Fontan patients.

Scalp topography of SEP late components in patients with supra-tentorial lesions

Somatosensory evoked potentials (SEP) to simultaneous bilateral median nerve stimulation were recorded in 7 patients with unilateral brain lesions, 8 patients with degenerative dementia, and 5 normal volunteers. Right-left amplitude difference was compared from serial topographic images and the amplitude was compared at homologous electrodes. In patients with unilateral lesions, the amplitude from the frontopolar, frontal, anterior-temporal, and/or occipital electrodes was smaller on the affected side at 240 and 360 msec, regardless of whether the subjects showed sensory deficit or not. No significant laterality was seen in the primary sensorimotor areas. Distribution obtained from the patients with degenerative dementia was quite symmetrical. A significant right-left amplitude difference was seen at the anterior temporal site at 180 and 240 msec in normal controls, although an almost symmetrical distribution was obtained on the topographic images. The late components of SEP are not associated with the primary somatosensory function, but possibly with other cortical pathways.

Origin of the left coronary artery from the right pulmonary artery

We report the successful surgical treatment of a 12-year-old boy with a rare type of Bland-White-Garland syndrome with mitral regurgitation, in which an anomalous left coronary artery arose from the middle portion of the right pulmonary artery, employing the direct translocation of the left coronary artery and mitral valvuloplasty.

A congenitally "poor" pulmonary artery is a major reason for exclusion from Fontan operation

We reviewed the clinical records of 185 patients who were possible candidates for Fontan operation. We did this to clarify whether all patients with suitable anomalies ultimately underwent a Fontan operation. Of the 152 patients with decreased pulmonary blood flow, 38 (26%) did not fulfill the criteria for Fontan operation, and 17 of the 33 patients (52%) with increased pulmonary blood flow (P < 0.01) were excluded as candidates. Of 48 non-candidate survivors, 19 had high pulmonary artery (PA) pressure or resistance and small PA (which we term "poor PA"), 17 had pulmonary hypertension, 6 had a markedly distorted PA, and 6 had severe ventricular dysfunction. A significant proportion of possible candidates with a suitable anomaly ultimately did not undergo a Fontan operation, because of "poor PA", a congenital condition that precluded Fontan operation.

[A successful surgical replacement for mitral regurgitation after cardiac arrest due to widely ruptured chordae tendineae]

A 47-year-old woman, who has mitral regurgitation previously diagnosed in another hospital, was transferred to our intensive care unit for acute congestive heart failure. Just after admission, her respiratory state became worse and she suddenly fell into cardiac arrest. Five minutes later she recovered through cardiopulmonary resuscitation. The pulmonary artery pressure, however, which reached 85/43 mmHg with a Swan-Ganz catheter, had been exceeding systemic pressure. On echocardiography ruptured chordae tendineae of the mitral anterior leaflet was most suspected. Five days after the intensive treatment with a use of IABP, we operated upon her. On the operative findings most rough zone chordae of both leaflets including two strut chordae were ruptured with severe prolapsing. Thus we chose prosthetic valve replacement rather than mitral valve repair. We replaced the mitral valve with a Carbomedix 25 mm. Postoperatively the mean pulmonary artery pressure remained still high as 40 mmHg. With a continuous intravenous administration of prostaglandin E1, the pulmonary artery pressure became lower gradually. The patient was able to wean from respirator on the 18th postoperative day. The patient was discharged on the 49th postoperative day. The mitral valve removed at operation showed myxomatous degeneration and idiopathic ruptured chordae tendineae on the pathological examination. In summary a 47-year-old woman underwent mitral valve replacement 5 days after cardiac arrest from acute severe mitral regurgitation due to widely ruptured chordae tendineae of both leaflets. She survived the operation and got well. The mitral valve showed myxomatous degeneration on pathological examination.