Sequential percutaneous microwave coagulation therapy for liver tumor

BACKGROUND

Percutaneous microwave coagulation therapy (PMCT) is effective for small liver tumors. To enhance the radicality of PMCT, we developed a sequential coagulation technique.

METHODS

After inserting the first guide-needle under sonography, multiple needles were placed through a disk-type introducer that was devised to guide needle puncture at regular intervals, and microwaves were irradiated. Six patients, including 4 with hepatocellular carcinoma and 2 with liver metastasis, underwent this technique for tumors of 15 to 80 mm in diameter.

RESULTS

This technique can coagulate an area up to 60 mm in diameter in one session. Insertion of multiple needles, ranging from 2 to 11, was successful without complications. Three patients undergoing curative PMCT developed no tumor recurrence. The other 3 received incomplete PMCT due to the large size and location of the tumor.

CONCLUSIONS

This preliminary study indicates the efficacy of this technique to facilitate and secure PMCT in selected patients with liver tumors.

A case of effusive-constructive pericarditis: an efficacy of GD-DTPA enhanced magnetic resonance imaging to detect a pericardial thickening

A 38-year-old man underwent pericardiectomy because of effusive-constrictive pericarditis. The gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging showed pericardial thickening separate from the effusion, which could not be shown by unenhanced computed tomography. Gd-DTPA enhanced magnetic resonance imaging could be useful for the early detection of effusive-constrictive pericarditis.

Metallic stents for low invasive recanalization of the portal veins with cancerous invasion--first case report

BACKGROUND/AIMS

Portal venous stenosis caused by cancer invasion has been difficult to treat and patients do not have any treatment options. On the other hand, protal venous stents have been applied to patients with variceal haemorrhaging associated with portal vein thrombosis. However, there have not been any reports concerning portal venous stents for malignant portal stenosis. The aim of this report was to apply metallic stent for malignant portal stenosis to reduce portal hypertension and restore portal venous blood flow, which in turn leads to the recovery of liver function.

METHODOLOGY

Two patients with portal hypertension caused by malignant portal stenosis were treated by metallic stent implantation. In one case, the stent was applied intraoperatively via the ileal vein and in the other case, it was applied postoperatively via transhepatic portal cannulation.

RESULTS

In the first case, portal pressure monitored before and after placement of the stent was 350 mmH2O and 200 mmH2O, respectively. Liver function tests showed normalization after stent placement. In the second case, over 3000 ml of ascites, which were drained through the drainage catheter every day, could be reduced remarkably, and one week later, the catheter could be withdrawn. Portal pressure before and after embedding the stent was 410 and 275 mmH2O, respectively. Both patients were discharged from the hospital and their recovery was uneventfully.

CONCLUSION

Both cases had an uneventful postoperative course, with normalization of liver function and cessation of ascites on the next postoperative day in case 2. Thus, portal venous stent should be considered a viable option for the treatment of malignant portal stenosis.

A computational fluid dynamic study of hawkmoth hovering

A computational fluid dynamic (CFD) modelling approach is used to study the unsteady aerodynamics of the flapping wing of a hovering hawkmoth. We use the geometry of a Manduca sexta-based robotic wing to define the shape of a three-dimensional 'virtual' wing model and 'hover' this wing, mimicking accurately the three-dimensional movements of the wing of a hovering hawkmoth. Our CFD analysis has established an overall understanding of the viscous and unsteady flow around the flapping wing and of the time course of instantaneous force production, which reveals that hovering flight is dominated by the unsteady aerodynamics of both the instantaneous dynamics and also the past history of the wing. <P> A coherent leading-edge vortex with axial flow was detected during translational motions of both the up- and downstrokes. The attached leading-edge vortex causes a negative pressure region and, hence, is responsible for enhancing lift production. The axial flow, which is derived from the spanwise pressure gradient, stabilises the vortex and gives it a characteristic spiral conical shape. <P> The leading-edge vortex created during previous translational motion remains attached during the rotational motions of pronation and supination. This vortex, however, is substantially deformed due to coupling between the translational and rotational motions, develops into a complex structure, and is eventually shed before the subsequent translational motion. <P> Estimation of the forces during one complete flapping cycle shows that lift is produced mainly during the downstroke and the latter half of the upstroke, with little force generated during pronation and supination. The stroke plane angle that satisfies the horizontal force balance of hovering is 23.6 degrees , which shows excellent agreement with observed angles of approximately 20-25 degrees . The time-averaged vertical force is 40 % greater than that needed to support the weight of the hawkmoth.

Intrahepatic cholangiocarcinoma associated with hepatolithiasis

BACKGROUND/AIMS

Despite sporadic reports of cholangiocarcinoma (CC) associated with hepatolithiasis, this entity has not been widely studied. The purpose of this study was to clarify its clinical features and optimal management by studying the 10 patients we have encountered with this condition.

METHODOLOGY

There were six women and four men, with a mean age of 61 years. The patients underwent anatomic hepatic resection (n = 5) or biliary drainage (n = 5). The clinical features and results of surgery were studied.

RESULTS

The characteristic findings included tumor-related symptoms, irregular ductal stricture or obstruction, and hepatic lobar atrophy with a whitish mass. The tumor and stones were located in the same hepatic lobe. Eight patients had advanced CC with periductal tumor infiltration, while two had in situ carcinoma characterized by intraductal tumor growth, papillary adenocarcinoma, and mucin-hypersecretion. Seven patients died within 6 months after surgery, while the remaining three, including the two with in situ carcinomas and one with an involved node at the dissected hilum, are alive more than 4 years after anatomic hepatic resection.

CONCLUSIONS

Recognition of the clinical features of CC associated with hepatolithiasis, which were clarified in this study, is important in treating patients with hepatolithiasis. An anatomic hepatic resection with hilar nodal dissection offers long-term survival in selected patients.

Long-term benefits of internal thoracic artery-coronary artery bypass in Japanese patients

OBJECTIVES

This study sought to determine the effects of grafting the internal thoracic artery (ITA) to the left anterior descending coronary artery (LAD) on long-term (10-year) survival, the cardiac death-free rate, and on the cardiac event-free rate in Japanese patients.

BACKGROUND

The use of ITA grafts has been reported to enhance postoperative survival and to decrease the occurrence of cardiac events in the Western literature. However, the survival benefits in Japanese patients, who may have different prognoses with coronary artery disease and a different fate of a saphenous vein graft, have not yet been determined.

SUBJECTS AND METHODS

A total of 954 consecutive patients who underwent coronary artery bypass graft operations (CABG) during the last 12 years at the Nara Medical University were followed and evaluated. Of these, 713 patients underwent ITA-CABG to at least the LAD (ITA group), and 241 patients received a saphenous vein graft (SVG) to the LAD (SVG group). At the time of operation, no significant difference was found between these two groups in age, sex ratio left ventricular ejection fraction, left ventricular end-diastolic pressure, cardiac index, incidence of unstable angina, or in the necessity for an emergency operation. However, those patients who received ITA-CABG had significantly higher incidences of diabetes mellitus, hyperlipidemia, and left main coronary artery disease.

RESULTS

The 10-year cumulative graft patency rate for the LAD was 23% higher in the ITA group (90.3%) compared to the SVG group (67.0%), (p < .0001). Despite increased preoperative risk factors, patients in the ITA group showed significant improvements in their 5- and 10-year cumulative survival rates as well as in their cardiac death-free and event-free rates. Furthermore, this study demonstrated that ITA grafts improved the prognoses of patients with diabetes mellitus or left ventricular dysfunction and lowered both the long-term postoperative cardiac-death rate and the cardiac-event rate.

CONCLUSIONS

The use of ITA grafts was effective in improving both the postoperative survival and cardiac event-free rates, and should be recommended in patients with diabetes mellitus or left ventricular dysfunction. ITA grafting to the LAD should be a routine operation in almost all categories of such patients.

Decision support for psychiatric diagnosis based on a simple questionnaire

This paper compares two classifiers: Pseudo Bayesian and Neural Network for assisting in making diagnoses of psychiatric patients based on a simple yes/no questionnaire which is provided at the outpatient's first visit to the hospital. The classifiers categorize patients into three most commonly seen ICD classes, i.e. schizophrenic, emotional and neurotic disorders. One hundred completed questionnaires were utilized for constructing and evaluating the classifiers. Average correct decision rates were 73.3% for the Pseudo Bayesian Classifier and 77.3% for the Neural Network classifier. These rates were higher than the rate which an experienced psychiatrist achieved based on the same restricted data as the classifiers utilized. These classifiers may be effectively utilized for assisting psychiatrists in making their final diagnoses.

The three-dimensional hydrodynamics of tadpole locomotion

Tadpoles are unusual among vertebrates in having a globose body with a laterally compressed tail abruptly appended to it. Compared with most teleost fishes, tadpoles swim awkwardly, with waves of relatively high amplitude at both the snout and tail tip. In the present study, we analyze tadpole propulsion using a three-dimensional (3D) computational fluid dynamic (CFD) model of undulatory locomotion that simulates viscous and unsteady flow around an oscillating body of arbitrary 3D geometry. We first confirm results from a previous two-dimensional (2D) study, which suggested that the characteristic shape of tadpoles was closely matched to their unusual kinematics. Specifically, our 3D results reveal that the shape and kinematics of tadpoles collectively produce a small 'dead water' zone between the head-body and tail during swimming precisely where tadpoles can and do grow hind limbs--without those limbs obstructing flow. We next use our CFD model to show that 3D hydrodynamic effects (cross flows) are largely constrained to a small region along the edge of the tail fin. Although this 3D study confirms most of the results of the 2D study, it shows that propulsive (Froude) efficiency for tadpoles is overall lower than predicted from a 2D analysis. This low efficiency is not, however, a result of the high-amplitude undulations of the tadpole. This was demonstrated by forcing our 'virtual' tadpole to swim with fish-like kinematics, i.e. with lower-amplitude propulsive waves. That particular simulation yielded a much lower Froude efficiency, confirming that the large-amplitude lateral oscillations of the tadpole do, indeed, provide positive thrust. This, we believe, is the first time that the unsteady flow generated by an undulating vertebrate has been realistically modelled in three dimensions. Our study demonstrates the feasibility of using 3D CFD methods to model the locomotion of other undulatory organisms.

Increased risk of coronary artery bypass grafting for left ventricular dysfunction with dilated left ventricle

The operative mortality and morbidity in patients with severe left ventricular dysfunction who undergo coronary artery bypass grafting (CABG) remain high. The low ejection fraction is the major risk factor for operative mortality. However, ejection fraction (EF) alone may not necessarily be an accurate predictor of operative mortality. We studied the correlation between indices of left ventricular volume and operative mortality. One thousand patients undergoing isolated coronary bypass operations were divided into three groups according to their preoperative ejection fraction. Fifty patients (group I) had severe left ventricular dysfunction (EF < or = 0.3), 56 patients (group II) had moderately left ventricular dysfunction (0.3 < EF < or = 0.4) and 894 patients (group III) had good left ventricular function (EF > 0.4). We analyzed the relationship between hospital mortality and left ventricular volume in 106 patients with an EF < or = 0.4.

RESULTS

Cardiac index was not significantly different among the three groups. The left ventricular end-diastolic pressure (LVEDP) and mean pulmonary artery pressure in groups I an II were higher than those in group III. The left ventricular end-diastolic volume (LVEDV) was 146 +/- 44 ml/m2 in Group I, 112 +/- 31 ml/m2 in Group II and 82 + 30 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The left ventricular end-systolic volume (LVESV) was 111 +/- 38 ml/m2 in Group I, 72 +/- 21 ml/m2 in Group II and 30 +/- 14 ml/m2 in Group III, respectively (Group I versus II, p < 0.05, Group I and II versus III, p < 0.01). The LVEDV and LVESV were higher in Group I than in Group II and both in Groups I and II were higher than in Group III. The hospital mortality of any cause before discharge was 8.0% (4/50) in Group I, 3.6% (2/56) in Group II, and 2.0% (18/894) in Group III. The mortality in Group I was higher than that in Group III, but the mortality between Groups I and II was not different. We assessed correlations between large left ventricle with left ventricular dysfunction and operative mortality in 106 patients with ejection fractions of < or = 0.4. The hospital mortality in patients with both under fraction 0.4 and an LVESV > or = 140 ml/m2 was 50% (4/8). This rate was higher than in patients with an LVESV between 80 and 140 ml/m2 (1.8%, 1/55) (p = 0.0006) and an LVESV less than 80 ml/m2 (2.3%, 1/43), (p = 0.0013). The hospital mortality in patients with an LVEDV > or = 200 ml/m2 was 67% (4/6). It was also higher than that in patients with an LVEDV between 200 and 120 ml/m2 (1.7%, 1/58), (p = 0.0001), and an LVEDV less than 120 ml/m2 (2.4%, 1/42), (p = 0.0004). We conclude that patients with a low ejection fraction and an elevated LVESV or LVEDV are at increased risk for hospital death following CABG.

[Life-threatening ventricular tachyarrhythmia after CABG in a patient with poor LV function--an experience with the implantable cardioverter defibrillator]

A 52-year-old man with reduced left ventricular function (ejection fraction 0.27) due to myocardial infarction, underwent coronary artery bypass grafting (CABG; LITA-LAD, free RITA-4PD) for angina pectoris. He had suffered from recurrent sustained ventricular tachycardia (VT) since 5 hours after CABG. This arrhythmia was resistant to various antiarrhythmic agents such as Lidocaine, Mexiletine, Disopyramide, Procainamide and Propafenone. He required mechanical circulatory supports (intra-aortic balloon pumping and percutaneous cardiopulmonary support) for the maintenance of hemodynamics during repeated VT that required cardioversions of a total of 441 times during 18 days. Following the administration of Amiodarone, the VT was successfully suppressed. However, he had repeated episodes of VT on exercise, thus, he underwent insertion of the implantable cardioverter-defibrillator at the 98 post-operative day, and he was successfully discharged at the 134 post-operative day after CABG. The instrument was verified to be normal in function after the VT induction test.

Three-dimensional arterial computed tomography and laparoscope-assisted splenectomy as a minimally invasive examination and treatment of splenic aneurysms

For the purpose of prophylactic treatment of splenic aneurysms, both examinations and treatments should be minimally invasive. Here, we report a case of a patient who underwent three-dimensional arterial computed tomography (CT) and laparoscope-assisted splenectomy with aneurysm resection as a combination of minimally invasive examination and treatment.

[Extended aortoplasty for supravalvular aortic stenosis with Williams syndrome]

We report a male case of supravalvular aortic stenosis associated with Williams syndrome requiring surgery at age 11. At 5 years of age, this boy presented with a harsh systolic heart murmur and was diagnosed as having a supravalvular aortic stenosis. In association with mental retardation, elfin face and bilateral inguinal hernias, he was diagnosed as a Williams syndrome confirmed by the chromosomal analysis revealing the deletion of 7q11.23. The pressure gradient across the stenotic lesion of the ascending aorta, which had been 35 mmHg at age 5, progressed to 80 mmHg at age 11 years. Extended aortoplasty was performed using a patch of 20 mm Hemashield graft prosthesis. Postoperative cardiac catheterization confirmed that the pressure gradient in the ascending aorta completely disappeared following surgery.

Minimally invasive hepatic resection using laparoscopic surgery and minithoracotomy

To our knowledge, we introduce a new technique to treat a patient with hepatocellular carcinoma having a main tumor and a small satellite nodule in segments IV and VI, respectively. The liver was laparoscopically mobilized; the dissection line was adequately exposed through a 12-cm anterior thoracic incision. Segment VI was resected without hilar dissection or parenchymal compression. The satellite nodule was coagulated with microwaves. The patient had an uneventful postoperative recovery. This technique potentially alleviates postoperative adhesion and allows a minimally invasive surgery.

Laparoscopic hepatic resection: a new and safe procedure by abdominal wall lifting method

HCC is well known for its high incidence of intrahepatic tumor recurrence and many patients suffering from them, usually undergo further treatments, such as PEI, TAE, MCNT or hepatic resection. However, conventional hepatic resection by large skin incision causes severe intraabdominal adhesions, which disturb US examination and further treatments. The aim of the laparoscopic procedure is to prevent intraabdominal adhesions. This is a study of the feasibility of laparoscopic hepatic resection without CO2 pneumoperitoneum, which is not yet popular, as a safe and effective procedure. The patient in this study had a solitary HCC in the lateral segment. Mobilization of the lateral segment, dissections of the left hepatic artery and portal venous branches, i.e. P2 and P3, were performed under CO2 gas insufflation. However, to avoid CO2 gas embolism, further procedures, including parenchymal compression and hepatic venous dissection, were performed using the abdominal wall lifting method without pneumoperitoneum. The patient could eat on the second postoperative day and had an uneventful postoperative recovery and was discharged from the hospital 13 days after surgery. Hospital stay was shorter than conventional hepatic resections with large skin incisions. The importance of this procedure lies in that it is not only a minimally invasive procedure, but also provides us with the possibilities of further treatments, including PEI and re-hepatic resection.

Preservation of myocardial function and metabolism at subzero nonfreezing temperature storage of the heart

BACKGROUND

The hypothermic simple immersion technique has been widely used to preserve the donor heart for transplantation. However, there is still controversy as to which temperature provides the best protection against prolonged ischemia. The low molecular weight solutes within cells depress the freezing point to -0.6 degree C. In practice, however, most cells do not freeze internally unless they are cooled below -10 degrees C. We investigated the effects of subzero nonfreezing storage at -1 degree C on the preservation of myocardial metabolism and function.

METHODS

Isolated Wistar rat hearts were subjected to 6 hours of preservation with the intracellular type University of Wisconsin solution; the hearts of the subzero group were preserved at subzero nonfreezing (-1 degree C) temperature, and the hearts of the control group were at 4 degrees C. Recovery of cardiac function, myocardial adenine nucleotides content, and myocardial water content were evaluated after preservation.

RESULTS

Subzero group resulted in significantly better aortic flow, cardiac output, and aortic systolic pressure than in the control group. Myocardial adenosine triphosphate, adenosine diphosphate, and total adenine nucleotides at end-storage were significantly better preserved in subzero group when compared with the control group. Myocardial water content at reperfusion significantly increased in the control group compared with the subzero group.

CONCLUSIONS

Storage in the intracellular type solution at subzero nonfreezing (-1 degree C) temperature as compared with 4 degrees C appears to prolong myocardial preservation with respect to the enhancement of postischemic functional recovery, preservation of myocardial adenine nucleotides during ischemia, and prevention of myocardial edema at reperfusion.

[Successful removal of an infected pacemaker electrode, drifted into the right atrium, by using a lead removal kit]

A 65-year-old male was suffered complications from an infected pacemaker in the left subclavian region. The generator was removed and its electrode was cut at the vascular entry. A new system was implanted on the other side. Two months later, he suffered from persistent fever which required administration of antibiotics for 2 months. 7 months later, the cut end of the infected electrode was found to have drifted into the right atrium. Its removal was performed to prevent a potential exacerbation of the systemic infection. We were able to pick up an end of the electrode using a basket catheter which was inserted through the right internal jugular vein to extract it. The lead was then successfully removed using a lead removal kit.

Ex vivo gene transfer into myocardium using replication-defective retrovirus

Heart transplantation is the most effective therapy for chronic severe heart failure, but there is an extreme shortage of hearts available. We examined the possibility that cardiomyocytes can be modified genetically prior to being grafted to the heart. We used a replication-defective retrovirus carrying the beta-galactosidase (beta-gal) reporter gene. The beta-gal gene was transduced into murine fetal cardiac myocytes by culturing a recombinant retrovirus-producing cell line in a Transwell plate hung into the primary cardiomyocyte culture. The cultured cells were stained with the di-beta-D-galactopyranoside (FDG) and were sorted by fluorescence-activated cell sorting (FACS). FACS analysis showed that 25.5 +/- 4.3% of the cardiomyocytes in a primary culture were positive for beta-gal activity. These cells were transplanted into the hearts of syngeneic adult mice. Expression of the beta-gal gene in the grafted cells was demonstrated by staining with 5-bromo-4-chloro-3-indoyl-beta-D-galactoside (X-gal). Gene expression was recognized as long as 6 mo after cell transplantation. Histologic analysis showed neither inflammation nor fibrous scar tissue on the host myocardium. This study demonstrated that genetically modified cardiac cells were transplantable to the heart.

[A case report of aortic root replacement with fresh aortic homograft for valve detachment due infective endocarditis]

A 28-year-old male received a redo aortic valve replacement (AVR) with a 19 mm St. Jude Medical mechanical valve 3 months after the initial AVR because of recurrent valve detachment. We re-operated on this patient by aortic root replacement using a fresh aortic homograft. The donor of the homograft was a 59-year-old female who died of a traffic accident. The aortic root and valve was harvested aseptically and stored in a nutrient medium including antibiotics at 4 degrees C for 4 days. At the 3rd operation, aortico-ventricular discontinuity and an annular-abcess-like cavity were found. After debridement, the cavity was closed with a homograft aortic wall and then aortic root replacement was performed using a fresh aortic homograft. At first, prosthetic valve detachment seemed to be caused by infective endocarditis on the basis of his clinical history. However, causative organisms had never been recovered from the blood or the specimens obtained at the time of operation and reoperation. Post-operative HLA examination revealed No. 51 on HLA-B locus and thus we suspected that valve detachment might have been due to inflammation of the aortic wall caused by a subtype of Behçet disease. The early post-operative course was uneventful with a low dose of predonine. Post-operative aortography showed no aortic regurgitation and normal coronary anastomosis. Unfortunately however, he died suddenly 8 months after the operation. Autopsy demonstrated the presence of aortic wall necrosis with massive infiltration of macrophages and leucocytes resulting in dehiscence of the coronary anastomotic site. The cause of homograft detachment could not be determined for sure but might be recurrent infective endocarditis, although causative organisms were never identified, or infective endocarditis in combination with Behçet vasculopathy.

Echocardiographic characteristics of the cryopreserved allograft aortic valve replacement assessed by intraoperative transoesophageal echocardiography

Improvements in cryopreservation techniques have made possible excellent long-term results using aortic valve allografts. Few studies, however, have examined the echocardiographic characteristics of allograft aortic valves and postoperative valve function. Aortic allograft function was evaluated in 16 patients by intraoperative transoesophageal echocardiography, postoperative catheterization, and angiography. The mean(s.d.) coaptation zone length of the allograft leaflet was significantly greater (7.3(1.4) mm) than that of the normal aortic valve (3.2(0.8) mm) (P < 0.01). No regurgitation was noted in any patients with coaptation zone length of 7-11 mm (P < 0.01). The increment of the leaflet coaptation zone length did not produce a significant pressure gradient during exercise and appeared to be one of the important mechanisms for the prevention of postoperative aortic regurgitation, because commissural orientations may be distorted in the new aortic position. This finding is consistent with the report that allografts with the largest diameter implantable in the recipient annulus should be selected for use.

Annuloplasty for severe mitral regurgitation due to dilated cardiomyopathy

We present a 74-year-old woman who underwent corrective annuloplasty for severe mitral regurgitation due to dilated cardiomyopathy. Postoperatively, congestive heart failure improved, with her New York Heart Association status changing from IV to II, although her cardiac functional improvement was minimal. Severe mitral regurgitation may be the indication for annuloplasty in symptomatic patients with dilated cardiomyopathy when cardiac transplantation is not indicated.