Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey's test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

Effect of simulated brushing on surface roughness and wear of bis-acryl-based materials submitted to different polishing protocols

Background

Material and Methods

Results

Conclusions

Automated diagnosis of heart disease in patients with heart murmurs: application of a neural network technique

This study was conducted to test a three-layered artificial neural network analysis of phonocardiogram recordings to diagnose, automatically and objectively, the condition of the heart in patients with heart murmurs. The data were recorded simultaneously in each of 49 patients with a heart murmur through eight microphones attached to the skin surface with adhesive tape, and were analysed by computer. The diagnosis was automated using a three-layered neural network technique. The neural network generated correct answers in over 70% of cases. Furthermore, about 80% of cases of two concurrent diseases were identified correctly. However, ventricular septal defects were incorrectly classified as aortic stenosis or aortic regurgitation, and patent ductus arteriosus was not diagnosed correctly. Accurate diagnoses can frequently be obtained using a neural network, but accuracy can be improved with further data accumulation.

[Aortic valve replacement in a renal transplant recipient]

A 65-year-old male was admitted to our hospital for surgical treatment of congestive heart failure with aortic regurgitation. He had received renal transplantation 15 years before in the United States, and had been under immunosuppressive regimen with ciclosporin and mycophenolate mofetil. Although the renal allograft function had been gradually deteriorating, and preoperative serum creatinine level was 1.8 mg/dl, and it decreased to 1.5 mg/dl after aortic valve replacement. Cryopreserved aortic allograft was needed for the aortic valve replacement. The reasons are; the patient may need hemodialysis (HD) or retransplantation of the kidney in the future, and the immunosuppressive therapy for kidney will provide good immunologic environment for second allograft, i.e.--aortic valve. He tolerated the operation well and the immunosuppressive agents were continued in the perioperative period. He is now in New York Heart Association (NYHA) class I.

[Secondary left main trunk coronary artery shock syndrome]

A 71-year-old male patient was admitted to our hospital and diagnosed as inferior wall acute myocardial infarction (AMI). Coronary angiogram revealed 3 vessel disease and left main trunk coronary artery (LMT) lesion. Because right coronary artery (RCA) had been recanalised, he was scheduled to operation. On the 6th day after admission, another attack made him fell into secondary LMT shock syndrome and lung edema. Emergency operation was performed and he recovered from heart failure. Here we report the case and added some considerations.

'No-Touch' isolation procedure for ruptured mycotic abdominal aortic aneurysm

The present study reports a case of the successful surgical repair of a ruptured infra-renal mycotic abdominal aorta with Enterobactor cloacae in a 66-year-old man. During the operative procedure, an extra-anatomic bypass was installed before the laparotomy in order to avoid bacterial contamination. A complete resection of the infected aorta, tapering of the arterial stumps, wrapping of the omentum, and ligation of the aorta and arteries with Teflon tapes was carried out. The patient is alive and well 1 year postsurgery.

Effects of recombinant human erythropoietin therapy on blood coagulation and fibrinolysis system

This study was designed to examine the effects of recombinant human erythropoietin (rHuEPO) therapy on blood coagulation and fibrinolysis in patients scheduled for elective heart surgery and undergoing preoperative autologous blood donation. Twenty-seven patients were studied, of whom 16 patients received rHuEPO (group E) and 11 patients no rHuEPO therapy (group N). The patients in group E were given 6000 units of rHuEPO intravenously every other day, three times a week, beginning from two weeks prior to the operation. In both groups, 400 ml of blood was collected preoperatively for predeposit once a week for two weeks, and the self-donated blood was returned to the patient intra- and postoperatively. Blood samples were drawn at the beginning of the study, immediately before the operation and two weeks after the operation. They were analyzed to assess blood coagulation, fibrinolysis, platelet function and vascular endothelial cell function, in order to examine the effects of the administration of rHuEPO. No significant difference was observed between the two groups in the degree of changes in these parameters following the operation. As enhancement of blood coagulability and fibrinolytic activity was evident postoperatively in both groups, changes in these parameters during the preoperative autologous blood donation period were also assessed excluding the postoperative data. Again, there was no significant intergroup difference in any of the markers evaluated. It was concluded that the administration of rHuEPO during preoperative autologous blood donation is unlikely to affect coagulation and fibrinolysis.

[Notification of unexpected patients' death to the police]

Controversies continue to exist in what situation the surgeons are obliged to report the perioperative patients' death to the police. With regard to this issue, Japan Surgical Society and twelve other Japanese Surgical Societies have declared that 1) patients' death due to evident malpractice must be reported to the police, 2) patients' death resulting from anticipated surgical complications need not be reported to the police, 3) an independent organization be founded for collection and investigation of medical accident/incident reports. Japan Surgical Society will take a responsibility of making a practical guideline as to the notification of accidents to the police and take a leadership in establishing the independent medical accident/incident center.

Favorable results in patients with small size CarboMedics heart valves in the aortic position

Hemodynamic performance of the CarboMedics heart valve in the aortic position and its clinical impacts were investigated in 126 consecutive patients. The actuarial survival rates of patients who had undergone isolated aortic valve replacement and concomitant aortic and mitral valve replacement were 82.6+/-5.7% and 71.0+/-9.2% at 8 years, respectively. Morbid events were rare, and almost all late survivors were free from evident cardiac symptoms regardless of the valve size. Echocardiography revealed suboptimal transvalvular pressure gradients and effective orifice areas of 19 mm and 21 mm valves. However, relief of the left ventricular overload and improvement of the clinical symptoms as well as cardiac function were comparable to those of patients with larger valves. Valve function measured by echocardiography did not show significant correlation to late outcome. Good results can be expected even in the presence of echocardiographic data such as peak pressure gradient over 40 mmHg, effective orifice area less than 1.0 cm(2), and effective orifice area index less than 0.7 cm(2)/m(2).

Experimental study of small arterial anastomosis with gelatin-resorcin-formaldehyde glue and collagen sheet

In cardiovascular surgery, the manual continuous suture has often been used for microvascular anastomosis, but the luminal irregularity often causes thrombotic stenosis in the anastomosis sites. The purpose of this study was to examine the feasibility of the combined use of gelatin-resorcin-formaldehyde (GRF) glue and a collagen sheet for the anastomosis of small arteries 3 to 4 mm in diameter in experimental animals. End-to-end anastomoses of the carotid and femoral arteries of mongrel dogs were carried out with the combined use of GRF glue and collagen sheet. The physical strength of the anastomosis, the histopathologic condition of the vassels, and the absorptivity and the inflammatory response of the glue were evaluated. The physical strength of the anastomosis sites was good and their flexibility optimal, the smooth luminal surface appeared excellent for preventing thrombotic stenosis in all follow-up periods, and the glue was absorbed almost completely within 12 weeks postoperatively. The combined use of GRF glue and collagen sheet would be feasible for the anastomosis of small arteries 3 to 4 mm in diameter and could substitute for the conventional suture method.

[What we must learn from recent medical accidents--experiences at the investigation committee]

The current publicity of medical accidents in Japan started with two well-known accidents. On January 11, 1999, a cardiac patient underwent a pulmonary operation, while a pulmonary patient received cardiac surgery at Yokohama City University Hospital. On February 11, 1999, detergent was inadvertently injected into a venous line at Hiroo Hospital in Tokyo. The author was invited as an indifferent specialist to serve on the Investigation Committee for these two accidents. This article describes the lessons to be learned from these two accidents.

Atrial ablation using an IRK-151 infrared coagulator in canine model

BACKGROUND

A method of atrial ablation was developed with the aim of shortening the aortic cross-clamp time during MAZE surgery. The IRK-151 infrared coagulator (Infrarot-Kontaktkoagulator: MBB: Messerschmidt-Bolkow-Blohn, Germany) was employed. Our aim was to electrophysiologically confirm the efficacy of this device.

METHODS

The MAZE-III procedure was performed in four mongrel dogs. Instead of a pulmonary vein-encircling incision, IRK-151 was applied several times to create a continuously overlapping circular lesion. After aortic declamping, the potentials of both atria were recorded using 18 bipolar electrodes implanted in the atrial wall. The recording conditions were: 1) sinus rhythm, 2) overdrive pacing from outside the encircling coagulation, and 3) overdrive pacing from inside the encircling coagulation.

RESULTS

1) There was no detectable potential within the pulmonary vein-encircling coagulation. 2) There was no conduction of paced atrial potential inside the encircling coagulation. 3) Only the area within the encircling coagulation was activated by the stimulus. Other parts of the atrium showed sinus rhythm simultaneously.

CONCLUSIONS

The left atrium within the pulmonary vein-encircling coagulation was isolated electrophysiologically.

Cardiac function evaluated by transesophageal echocardiography during cardiopulmonary bypass

OBJECTIVE

To evaluate cardiac function at cardiopulmonary bypass weaning, we applied a new technique clinically to determine the approximated Emax without using a conductance catheter.

METHODS

Subjects were 5 patients. The left ventricular end-systolic pressure was obtained by overlaying the radial arterial pressure curve on the left ventricular pressure curve. Left ventricular end-systolic volume was assessed by a transesophageal echographic apparatus. At cardiopulmonary bypass weaning, volume loading was applied to increase left atrial pressure by a few mmHg while fixing the pump flow rate at half flow. Changes in left ventricular end-systolic volume and approximated left ventricular end-systolic pressure for total heart beat were plotted during this period, and the gradient of the regression line was taken as approximated Emax.

RESULTS

Approximated Emax ranged from 1.29 to 3.28 (mean 2.13 +/- 0.72), and its correlation coefficient was 0.80 +/- 0.06.

CONCLUSION

Our new technique is useful in evaluating cardiac function during cardiopulmonary bypass.

Systemic-to-pulmonary shunt in a patient with isolation of the subclavian artery

A surgical procedure is described that was carried out to treat an 18-month-old boy with tetralogy of Fallot, right aortic arch, and isolation of the left subclavian artery. The patient underwent a descending aorta-right pulmonary artery shunt using a polytetrafluoroethylene graft, as a systemic-pulmonary shunt. The effectiveness of this procedure in patients with some special conditions is discussed.

Estimation of functional liver reserve in patients before cardiac surgery using antipyrine plasma clearance test

BACKGROUND

Hyperbilirubinemia is not uncommon and is sometimes fatal after valvular surgery. One important cause of it is a poor functional liver reserve, however, conventional tests reflect hepatic blood flow and do not offer precise evaluation of the pure functional liver reserve. Antipyrine has particular pharmacological properties, and its plasma clearance represents quantitatively the functional capacity of the liver. In this study, we measured antipyrine plasma clearance in cardiac surgical patients and evaluated the feasibility of using this parameter as a predictor of the risk of postoperative hyperbilirubinemia.

METHODS

The plasma clearance of antipyrine was measured preoperatively in 40 cardiac patients undergoing mitral and/or tricuspid valvular surgery and its relations with hemodynamics or postoperative course were studied.

RESULTS

Antipyrine clearance in preoperative patients was 0.365+/-0.175 (mean +/- SD) ml/min/kg, lower than the normal range (0.405+/-0.04 ml/min/kg), and showed no correlation with cardiac index, while the plasma disappearance rate of indocyanine green depended on the cardiac index. The maximum postoperative total bilirubin level showed significant correlation with antipyrine clearance (r=-0.699); this correlation coefficient was greater than that with indocyanine green (-0.477). The correlation was more prominent in patients with cardiac dysfunction. Furthermore, antipyrine clearance showed significant predictability of the duration of ICU stay.

CONCLUSIONS

Antipyrine clearance provides a precise estimate of functional liver reserve which is independent of hemodynamics and predicts the risk of postoperative hyperbilirubinemia in preoperative cardiac patients.

Management of severe acute pancreatitis with a somatostatin analog in a patient undergoing surgery for dissecting thoracic aneurysm: report of a case

A patient who was admitted to our hospital to undergo surgery for a dissecting thoracic aneurysm suffered preoperatively from severe acute pancreatitis with pancreatic pseudocysts. Computerized tomography (CT) demonstrated the presence of new fluid collection around the cyst with the absence of pancreatic necrosis. He was given a somatostatin analog (sandostatin), which was effective in decreasing the abdominal symptoms, leukocyte counts, and the serum C-reactive/protein level. A CT scan revealed that the pancreatic pseudocyst and peripancreatic fluid collection had disappeared. Although somatostatin has been reported to be ineffective for acute pancreatitis with necrosis, pancreatitis without necrosis may regress after treatment with sandostatin. This is probably due to its suppressive effect on the exocrine function, thus resulting in a decrease of pancreatic juice infiltration.

Transthoracoscopic needle biopsy for indeterminate lung nodules

BACKGROUND

The usefulness of transthoracoscopic needle biopsy for preoperatively indeterminate intrapulmonary nodules was evaluated.

METHODS

Thoracoscopy was performed on 38 patients with pulmonary solitary nodules suspected to be primary lung carcinomas. When the nodule was localized by simple observation or tactile sensor, a biopsy specimen of the tumor was obtained by a biopsy needle introduced through a trocar.

RESULTS

The nodules were 7 to 55 mm in diameter. All were located in the peripheral region of the lung. Biopsy specimens were obtained even from 17 nodules with no associated pleural changes. By cytology, all the malignant tumors were precisely diagnosed, 29 as primary lung cancers and 3 as metastatic lung neoplasms. Five of the remaining six benign nodules were not precisely diagnosed. However, they were cytologically classified as class I.

CONCLUSIONS

Transthoracoscopic needle biopsy is feasible for diagnosing small intrapulmonary nodules, particularly those of malignant neoplasms. As compared with thoracoscopic excisional biopsy, transthoracoscopic needle biopsy saves time and may reduce the possibility of tumor dissemination during the procedure.

Intravalvular implantation technique for aortic valve replacement in aortitis syndrome

BACKGROUND

Paravalvular leakage is one of the most serious complications of aortic valve replacement in patients with aortitis syndrome. The purpose of this study was to compare the effectiveness of the intravalvular implantation technique in preventing paravalvular leakage with that of the conventional technique.

METHODS

Since 1982, 14 patients with aortic regurgitation caused by aortitis syndrome have undergone aortic valve replacement at our institute. An intravalvular implantation technique was applied in 7 of the 14 patients. The technique consists of suturing a prosthetic valve to the aortic annulus and sandwiching the leaflets between exogenous felt pledgets and the inflamed aortic annulus.

RESULTS

Paravalvular leakage occurred in 3 of 7 patients in the conventionally treated group and in none of 7 in the intravalvular implantation group.

CONCLUSIONS

The intravalvular implantation technique is effective in preventing paravalvular leakage in patients with aortitis syndrome.

[Superimposed infective endocarditis at anterior mitral leaflet in a patient with prolapsed posterior leaflet: report of a case treated with valvuloplasty]

A 64-year-old male patient was referred to our hospital for massive mitral regurgitation after infective endocarditis. Echocardiography revealed vegetation on the atrial surface of the midst of the anterior mitral leaflet. At operation it was found that the anterior leaflet was perforated due to infection, and the posterior leaflet was prolapsed resulting from elongated chordae. Anterior leaflet was patched with autologous pericardium, and posterior leaflet was repaired with rectangler resection. An autologous pericardial strip was sutured to posterior mitral annulus. The patient survived the operation without complication.

Oxygen utilization and hemodynamic response during exercise in children after Fontan procedure

Eight patients, 9.1 to 16.5 years of age, were studied 2.8 to 8.5 years after Fontan operation. Oxygen utilization was determined during upright bicycle exercise. The cardiac index and stroke index were measured by echocardiography and the anaerobic threshold was determined. The results were compared with 10 patients after surgical closure of the atrial septal defect. Anaerobic threshold (AT) in Fontan patients was lower than in the control subjects. Oxygen consumption at each stage of exercise was significantly lower in the Fontan group compared with the control subjects. From the beginning of exercise until AT, the increase in stroke index was lower in the Fontan patients than in the control subjects. After that point, the stroke index decreased significantly in the Fontan patients while it remained almost at the same level in the control subjects. Significant correlations were observed between the oxygen pulses and the stroke index at AT both in the control and Fontan groups. These results suggest that impaired exercise capacity in Fontan patients is mainly due to a subnormal response of the stroke index at AT and to the decreased response of the stroke index and the heart rate at the maximal workload.

Atrial ablation with an IRK-151 infrared coagulator

BACKGROUND

The purpose of this study was to develop a method of atrial ablation. In the IRK-151 infrared coagulator, light from a tungsten-halogen lamp is focused into a quartz rod. The distal exit plane is connected to a tip made of sapphire to allow linear ablation.

METHODS

Thirty-six lesions were created in 9 mongrel dogs. The beating ventricular myocardium was ablated from the epicardium. In each dog, 4 lesions were created by using the following durations of application: 3, 9, 15, and 21 seconds. After the ablation, the myocardium was fixed and stained. A linear lesion on the beating right atrial free wall was created. Before and after the ablation, epicardial plaque-electrode mapping was performed. Three months after ablation, remapping was performed.

RESULTS

The ablated myocardium had well-demarcated necrosis without carbonization or vaporization. The maximum depth was 10.3 +/- 0.8 mm. The conducting pathway was blocked. The block, once made, continued for 3 months.

CONCLUSIONS

The IRK-151 produces well-demarcated lesions that were deep enough for atrial ablation to block the conducting pathway.

[Thoracoscopic decortication for chronic empyema thoracis: report of a case]

Thoracoscopic surgery for empyema thoracis treatment is still uncommon in Japan. We report a case of chronic empyema thoracis which was successfully treated with decortication through thoracoscopy. A 63-year-old man presented with respiratory distress, appetite loss and hoarseness. He had been suffering from diabetes mellitus for 13 months. His chest X-ray film revealed that he had suffered from the left chronic empyema. As the decortication procedure was feasible at the preliminary exploration, it was then performed through the thoracoscopy. The lung re-expanded well after the pleural peel was removed. His chest drainage tube was drawn out on 19th postoperative day.

Developmental changes in carbonic anhydrase II in the rat kidney

We examined the distribution and maturational changes of carbonic anhydrase I (CAI) and carbonic anhydrase II (CAII) in microdissected nephron segments of Sprague-Dawley rats. CAI and CAII proteins were measured by enzyme-linked immunosorbent assay. CAI was not detected in any nephron segment in 7-week-old rats. CAII was present in the collecting ducts, proximal tubules, and thick ascending limbs of loop of Henle in 7-week-old rats. CAII contents were significantly higher in the early proximal tubules (S1) than in second (S2) and late (S3) portions of the proximal tubules, while the contents in S1 were less than in cortical collecting ducts (CCD), outer stripe and inner stripes of the outer medullary collecting ducts (OMCDo and OMCDi). CAII content in each of S1, CCD, and OMCD of 1-week-old rats was only 14% or less of that of adults, but increased steeply during the 2nd and 3rd weeks of life, reaching almost 40% at 3 weeks of age and 97% at 7 weeks. Our results indicate that CAII is present throughout the entire nephron of the rat, and that CAII content in S1, CCD, and OMCD increases exponentially during the first 7 weeks of life. Our data suggest that the immature low levels of CAII may explain, at least in part, the limited capacity of urinary acidification during neonatal life. Further studies are necessary to establish the role of such changes in CAII content in acid-base homeostasis during neonatal life.

[Open heart surgery in patients with a tracheostoma]

From April 1992 to May 1997 six patients underwent open heart surgery, who had tracheostoma at the time of operation. The sternum was divided completely in three patients whose tracheostoma lay highly on the neck, and it was cut transversely on the manubrium at the level of the first intercostal space, below which it was split longitudinally in two patients (partial median sternotomy). In one patient right anterolateral thoracotomy was used. There were no operative death and no complication related to infection. A left internal thoracic artery (LITA) was used successfully for a bypass conduit in two patients who underwent partial median sternotomy. Dissection of the proximal portion of the LITA through the second intercostal space prior to the sternotomy made the graft procurement feasible in this particular situation. In conclusion, full-length sternotomy is performable safely when the tracheostoma lies highly on the neck, and the partial sternotomy up to the midmanubrium is applicable, including LITA harvesting, even if it is just at the sternal angle.

Persistent hemolysis after coil occlusion of a patent ductus arteriosus in a patient with aortic regurgitation

We report a rare case of hemolysis after coil occlusion of a patent ductus arteriosus (PDA), which was treated by surgical removal of the coil and closure of PDA. A 65-year-old woman was admitted to our hospital with congestive heart failure due to severe aortic regurgitation associated with PDA. Before undergoing open heart surgery she underwent closure of the PDA using a Jackson coil as an adjunct of treatment to improve her hemodynamic state. However, a small residual shunt resulted in severe hemolysis. Two weeks after the intervention she underwent aortic valve replacement and PDA closure after removal of the coil through the main pulmonary artery under moderate hypothermia and temporary circulatory arrest. Hemolysis is always secondary to a residual leak and several methods have been reported to manage this complication. Our report suggests that early surgical retrieval of the coil before the organized thrombus is formed, can be safely performed even in an elderly patient whose ductus is usually fragile.

[Atrial septal defect and severe pulmonary hypertension in an adult who needed nitric oxide inhalation after repair]

A 51-year-old male was diagnosed as having an ostium secundum atrial septal defect with severe pulmonary hypertension. Although pulmonary artery pressure was as high as 96/32 and pulmonary vascular resistance was 14.2 U.m2, he underwent corrective surgery, because pulmonary to systemic blood flow ratio was 2.0. After he regained consciousness in ICU, pulmonary hypertensive crises recurrently occurred and the hemodynamics became quite unstable. Administration of conventional drugs proved to be ineffective. Since inhalation of low dose (3-4 ppm) nitric oxide was started, however, his condition was markedly improved and he recovered uneventfully thereafter. Two years later, pulmonary artery pressure was reduced to 52/28 and pulmonary vascular resistance was 9.9 U.m2. Although good outcome can not be expected in all surgically treated cases, we should refrain from deciding easily that surgery is contraindicated, because no criteria of surgical indication for atrial septal defect with pulmonary hypertension appears to be perfect.

Coronary artery bypass grafting by median sternotomy in patients with a tracheostoma

The approach to the heart for open heart surgery in patients with a tracheostoma requires careful consideration. The presence of a tracheostoma interferes with the standard sternotomy and increases the risk of mediastinitis. We have successfully performed coronary artery bypass grafting in two patients with a tracheostoma using the limited median sternotomy and describe the surgical procedure used in these patients.

[Cardiac surgery in Jehovah's Witness]

Clinical experiences of 35 cardiothoracic operations in Jehovah's Witness patients were presented with special reference to a method of taking informed consent for surgery. At first the surgeon explained the details of the proposed surgery including its risks and benefits. He should also express his confidence in accomplishing the operation without blood transfusion. Otherwise he should not dare to perform the operation. The surgeon asked the patient to talk about his or her religious belief in transfusion denial. Then the surgeon was allowed to talk about his professional duty and ethical belief in saving the patient at all costs. Finally, both the patient and the surgeon would sign the document of informed consent without fully determining whether or not the patient would undergo transfusion at an unexpected situation since the possibility of such unexpected necessity of blood transfusion was believed extremely low by both the surgeon and the patient. The trust of the patient in the technique of the surgeon was the key to this agreement.

Repair of ruptured anastomotic aneurysm: elephant trunk technique after endovascular covered stents

Endovascular covered stents were successfully applied to temporarily halt hemoptysis and postpone surgical intervention in a 69-year-old man with a ruptured anastomotic false aneurysm of the distal aortic arch. Surgical graft implantation was performed successfully by the elephant trunk technique 14 days after the endovascular stent-grafting, at which time aspiration pneumonia had subsided.

[Heart and lung surgery 86-96]

During a period between April 1, 1986 and December 31, 1996, a total of 3190 cardiothoracic operations were performed in our Department. The overall mortality was 4.1% The prerequisite for successful accomplishment of clinical research was discussed in detail.

Mitral valve repair through combined left atrial and ventricular approach for congenital mitral stenosis

A 3-year-old boy underwent mitral valve repair for congenital mitral stenosis through combined superior-septal atriotomy and apical left ventriculotomy. The operation was performed safely with excellent exposure of the subvalvular apparatus by the ventricular approach, while sufficient visualization of the valvular lesion was obtained by the atrial approach. Postoperative echocardiography demonstrated normal left-ventricular motion and no residual mitral stenosis.

[Reoperation for mitral regurgitation 13 years after aortic valve replacement and manouguian's anulus enlargement: report of a case]

The patient was 22-year-old female. She had undergone aortic valve replacement and Manouguian's anulus enlargement with low porosity woven Dacron patch for congenital aortic stenosis 13 years ago, and developed mitral regurgitation 9 years after that operation. Two regurgitant flow were observed. One was originated from the orifice due to mitral prolapse. The other was from a tear in the anterior leaflet. It was around the tip of the prosthetic patch, approximately 7 mm in size, and was repaired easily. But the mitral valve itself was found to be malformed and prolapsed, requiring mitral valve replacement. Her postoperative course was uneventful.

The stiffness of lymph nodes containing lung carcinoma metastases: a new diagnostic parameter measured by a tactile sensor

BACKGROUND

It is believed that the stiffness or hardness of a lymph node containing a metastasis differs from that of lymph node without a metastasis because of the difference in tissue density, which is derived from the lymph node's histopathologic features. Prior to this study, however, there had been no attempts to quantify the hardness or stiffness of lymph nodes. The authors developed a new tactile sensor and system for measuring the stiffness (g/cm) of lymph nodes accurately, and they studied its utility as a tool for diagnosing lymph node metastases.

METHODS

Clinical specimens were obtained from 14 patients who underwent lobectomy or pneumonectomy with hilar and mediastinal lymph node dissection for nonsmall cell lung carcinoma at the University of Tokyo between January and July 1996. With the tactile sensor developed by the authors, 212 resected lymph nodes were measured for their stiffness.

RESULTS

Among these 212 resected lymph nodes, 57 were diagnosed as containing metastases (38 from adenocarcinomas and 19 from squamous cell carcinomas). The mean stiffness of the lymph nodes that contained metastases was 3.35 +/- 1.57 g/cm, and that of lymph nodes without metastases was 1.23 +/- 0.50 g/cm (P < 0.001). Receiver operating characteristic analysis revealed that the area under the curve was 0.93, indicating excellent accuracy of the method. When the cutoff was 1.5 g/cm, the sensitivity was 91.2% and the specificity was 78.1% for detection of lymph node metastases.

CONCLUSIONS

Measurement of the stiffness of resected lymph nodes was confirmed as an accurate approach to diagnosing lymph node metastases without knowledge of other factors, such as lymph node size or color.

Mitral valve repair with extensive resection of the anterior leaflet for regurgitation due to Barlow's disease. Report of a case

We recently performed mitral valve repair for a case of mitral regurgitation due to Barlow's disease, which is relatively rare in Japan. Both the anterior and posterior leaflets were affected by advanced myxomatous change, and appeared markedly thickened and redundant. Although extensive resection of the anterior leaflet is not a generally accepted method, nearly one fourth of the anterior leaflet was resected in this case. Now, at 36 months after the operation, there is only trivial regurgitation and the patient is doing well and without symptoms. We believe that extensive resection of the anterior leaflet can be a useful treatment for repair of a redundant anterior leaflet with excess tissue.

[Reoperation for relief of valvular and supravalvular stenosis late after aortic valve replacement with Manouguian's anulus enlargement: report of a case]

Thirteen year-old boy who received aortic valve replacement with Manouguian's anulus enlargement for congenital aortic stenosis 7 years ago developed valvular and supravalvular stenosis. Pressure gradient between left ventricle and aorta was 55 mmHg. The etiology of supravalvular stenosis was extensive patch plasty of ascending aorta and severe degeneration of expanded polytetrafluoroethylene patch. Moreover, white hard mass existed just outside the patch and was one of the components of the stenosis. This mass was acellular calcification without foreign body reaction. Degenerated prosthetic patch was thoroughly resected, and redo Manouguian's procedure with autogeneous pericardium was performed. We tried to use two sizes larger 21 mm valve, but, after all, 19 mm valve was sewn into place. His postoperative course was uneventful.