Atezolizumab plus bevacizumab versus lenvatinib or sorafenib in non-viral unresectable hepatocellular carcinoma: an international propensity score matching analysis

BACKGROUND

A growing body of evidence suggests that non-viral hepatocellular carcinoma (HCC) might benefit less from immunotherapy.

MATERIALS AND METHODS

We carried out a retrospective analysis of prospectively collected data from consecutive patients with non-viral advanced HCC, treated with atezolizumab plus bevacizumab, lenvatinib, or sorafenib, in 36 centers in 4 countries (Italy, Japan, Republic of Korea, and UK). The primary endpoint was overall survival (OS) with atezolizumab plus bevacizumab versus lenvatinib. Secondary endpoints were progression-free survival (PFS) with atezolizumab plus bevacizumab versus lenvatinib, and OS and PFS with atezolizumab plus bevacizumab versus sorafenib. For the primary and secondary endpoints, we carried out the analysis on the whole population first, and then we divided the cohort into two groups: non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) population and non-NAFLD/NASH population.

RESULTS

One hundred and ninety patients received atezolizumab plus bevacizumab, 569 patients received lenvatinib, and 210 patients received sorafenib. In the whole population, multivariate analysis showed that treatment with lenvatinib was associated with a longer OS [hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.44-0.95; P = 0.0268] and PFS (HR 0.67; 95% CI 0.51-0.86; P = 0.002) compared to atezolizumab plus bevacizumab. In the NAFLD/NASH population, multivariate analysis confirmed that lenvatinib treatment was associated with a longer OS (HR 0.46; 95% CI 0.26-0.84; P = 0.0110) and PFS (HR 0.55; 95% CI 0.38-0.82; P = 0.031) compared to atezolizumab plus bevacizumab. In the subgroup of non-NAFLD/NASH patients, no difference in OS or PFS was observed between patients treated with lenvatinib and those treated with atezolizumab plus bevacizumab. All these results were confirmed following propensity score matching analysis. By comparing patients receiving atezolizumab plus bevacizumab versus sorafenib, no statistically significant difference in survival was observed.

CONCLUSIONS

The present analysis conducted on a large number of advanced non-viral HCC patients showed for the first time that treatment with lenvatinib is associated with a significant survival benefit compared to atezolizumab plus bevacizumab, in particular in patients with NAFLD/NASH-related HCC.

Abstract P3-03-18: Invasive lobular carcinoma does not fit to axillary lymph node management according to NCCN guideline influenced by ACOSOG Z0011 criteria

[Introduction] Surgery for breast cancer (BC) became less invasion, from radical mastectomy to modified or breast conserving surgery (BCS). Axillary lymph node (ALN) management for cN0 also became less, from ALN dissection (ALND) to sentinel lymph node (SLN) biopsy. In some cases, management without ALND is allowed even if ALN macro-metastasis exist.

[Background] ALND for SLN metastasis positive case is useful for local control, staging and decision making for post-operative treatment. Since the ACOSOG Z0011 trial (Z11) result was reported, however, the necessity of ALND, even if SLN metastasis, became less. In the NCCN guideline (NCCN), strongly influenced by Z11, for cN0 BC with SLN metastasis, operations without ALND are allowed in cases of T1 or T2, the number of metastatic ALN 1 or 2, BCS with whole breast radiation and no-neoadjuvant therapy. This does not mean ALND was abolished but the position of ALND changed, from the perspective that over invasive procedure must be prohibited with appropriate pre-operative and intra-operative diagnosis. If there are some discordance between clinical and pathological diagnosis of tumor size or ALN metastasis, however, the criteria for axillary operation by NCCN will not be recommended. We have major two types of invasive carcinoma, ductal (IDC) and lobular (ILC). Z11 or NCCN did not describe about these two phenotypes. We compared these at the point of suitable axillary management.

[Subjects] Out of 1320 invasive BC (IDC; 1212, ILC; 108) cases in our hospital from January 2008 to January 2018, 1210 cases (IDC; 1113, ILC; 97) with T1/T2 and cN0 were reviewed in two points, the judgment of the competence for BCS was appropriate or not, and cN0 reflected the condition for the omission of ALND (ALN metastasis within 2) or not.

[Results] The difference of diameter between cT and pT; dT (=pT-cT) were measured significantly larger in ILC (0.68±1.97cm) than IDC (0.01±1.08cm)(p<0.01, t-test) with the wide scattering. We can make proper evaluation for the cT of IDC, but underestimate for ILC. The conversion rate from cN0 to pN1 was significantly higher in ILC (33/97; 34.0%) than IDC (238/1113; 21.4%)(p<0.01, χ2 test). In addition, the cases with 3 or more ALN metastasis, this means ALND is necessary, was observed with significantly higher frequent in ILC (13/97; 13.4%) than IDC (74/1113; 7.1%)(p=0.02, χ2 test). Clinical evaluation for ALN in ILC was difficult and inaccurate.

[Discussion] Commonly, ILC makes diffuse spread into the breast tissue. This feature will make it difficult to evaluate the clinical appropriate tumor size. Because of not only underestimation but wide scattering, the diagnosis for safety BCS may not be guaranteed in ILC. For ALN, cN0 did not reflect adequately the condition of omission for ALND in ILC compared with IDC. ILC patients with SLN metastasis have to be performed ALND at higher risk. These facts will mean that ILC does not fit to ALN management according to NCCN. Few guidelines separate ILC from IDC for the axillary management. The validation of clinical trials for ALND should be done in histological subtype as well as intrinsic again. Clinically, we must observe carefully in cases of ILC without ALND according to Z11.

Citation Format: Miyamoto T, Fujisawa T, Morishita A, Yanagita Y, Fujii T-A. Invasive lobular carcinoma does not fit to axillary lymph node management according to NCCN guideline influenced by ACOSOG Z0011 criteria [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-18.

Cell Specific Matrix Metalloproteinase-1 Regulates Lung Metastasis Synergistically with Smoke Exposure

MMP1, a matrix metalloproteinase that degrades the extracellular matrix, is produced not only by cancer cells but also synthesized in stromal and inflammatory cells during tumorigenesis, invasion and lung metastasis. However, the function of MMP1 expression from host cells, especially tumor-associated macrophages (TAMs), and cells in the lung parenchyma remains to be elucidated. Here we demonstrate that in vitro macrophages co-cultured with tumor cells drastically enhance MMP1 expression, which is further exacerbated upon cigarette smoke exposure. In addition, in vivo, macrophage specific MMP1 was found to have a causative role in primary tumor development and lung metastasis, which was enhanced under smoke exposure as demonstrated in a transgenic mouse model that expressed human MMP1 specifically in macrophages (Mac-MMP1). In contrast, MMP1 from lung cells (Lung-MMP1) reduced colonization to the lung despite the fact that collagen deposition decreased in the Lung-MMP1 mouse tumors. These results demonstrate that the varying cellular source of MMP1 in tumors leads to the complexity observed in the tumor microenvironment. Furthermore, macrophage-specific inhibition of MMP1 secretion may be a potential therapy to aid in the reduction of lung metastasis.

Abstract P3-07-38: Increment of neutrophil/lymphocyte ratio (NLR) can be one of the useful predictive markers for the metastatic breast cancer (MBC) with first line hormonal therapy (HT)

[Introduction] Cancer microenvironment formed by the immune and inflammatory cells is noticed to be one of the factors for tumor growth, invasion or metastasis. To figure out the systemic inflammatory environment, the neutrophil / lymphocyte ratio (NLR) is a useful method and a simple indicator. We have some reports that NLR can predict the prognosis in many malignancies, including breast cancer, as I reported in SABCS 2014, however, NLR cannot be a predictive marker in major cancers, because the usage with anti-cancer agents will make NLR status out of order. In hormonal receptor positive metastatic breast cancer (HR+ve MBC), we choice hormonal therapy (HT) for the first line, mainly. HTs have little influence for NLR, therefore, the change of NLR, increment or decrement, can reflect the systemic inflammatory status and be a useful predictive marker for the HR+ve MBC with HTs.

[Purpose] I define dNLR as the difference between NLR at the 2-3 months after HT and before HT. To evaluate the dNLR affects the Overall Survival (OS) and Progression Free Survival (PFS) of the patients of MBC or not.

[Patients] From 2003 to 2013, we have 299 MBC patients in our hospital. Out of them, 134 patients had HTs as first line, included 18 Stage4 patients at the first visit. Median Disease free survival (DFS) is 1497-day, the median OS after the recurrence is 1472-day. Average value of the NLR before HT is 2.62. The reasons of MBC are bone metastases (mets), pleural and pulmonary mets, liver mets, lymph node mets, central nervous system (CNS) mets, unresectable metastatic chest wall recurrence, or other.

[Results] By univariate analysis, DFS < 1000 (p<0.01) and liver mets (p<0.05) made a contribution to poor OS. dNLR>=0.5 (p<0.05), liver mets (p<0.05) and 2 or more organs involvements (p < 0.05) made a contribution to poor PFS. With multivariate analysis, for OS, only DFS < 1000 was an independent prognostic factor. And for PFS, only dNLR>=0.5 was an independent predictive factor. Poor OS factors by univariate analysis had no influence for PFS as well as poor PFS factors did not reflect the OS.

[Discussion] The dNLR was a predictive marker for HR+ve MBC which we can easily and simply examine by blood sample. Now we cannot reveal the relationship with dNLR and OS, however, this fact suggests that we can decide to stop the first line HT and select the second line therapy using with not only images or tumor makers but also dNLR. This can certainly contribute for good OS. It remains some questions between dNLR and other examinations, for example, which can detect the patient status earlier and more accurate? First, we need to accumulate further retrospective cases and plan the prospective study to make sure of the adequate treatment divided by dNLR.

[Conclusion] The dNLR>=0.5 is one of the independent predictive markers for HR+ve MBC with first line HT.

Citation Format: Miyamoto T, Fujisawa T, Morishita A, Yanagita Y, Kuwano H. Increment of neutrophil/lymphocyte ratio (NLR) can be one of the useful predictive markers for the metastatic breast cancer (MBC) with first line hormonal therapy (HT). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-38.

Electric Quadrupole Interactions of the Short-Lived β-Emitter 12N in Insulator Crystals (12N Implanted in Single Crystal TiO2)

The electronic structure of nitrogen atoms as impurities in an ionic TiO2 crystal has been investigated by analyzing electric field gradients (EFGs) measured by use of short-lived β-emitting 12N implant-ed following nuclear reactions. Conventional β-NMR and its modification, suitable for the detection of quadrupole effects in the NMR spectra, were used for the investigation of hyperfine interactions of 12N located in substitutional sites of O atoms and interstitial sites in the crystal. In order to deduce absolute values of the EFGs from the obtained eqQ/h, the quadrupole moment of 12N has been determined from the NMR detection of 12N implanted in BN(hexagonal) crystal. Here the EFG at the N atom in BN was measured by detecting the FT-NMR of 14N in the crystal. The EFGs in TiO2 are compared with the theoretical predictions based on the ab initio band-structure calculation in the framework of the KKR method.

Human papillomavirus detection and typing in thin prep cervical cytologic specimens comparing the Digene Hybrid Capture II Assay, the Roche Linear Array HPV Genotyping Assay, and the Kurabo GeneSquare Microarray Assay

Three methods for the detection of HPV DNA were compared in cervical cytologic specimens: the Digene Hybrid Capture II Assay (HC), the Roche Linear Array HPV Genotyping Assay (LA) and the Kurabo GeneSquare Microarray (GS). The main goals of the study were to correlate cytology with HPV detection and to determine agreement between assay pairs for HPV detection. Thin-prep Pap smears were performed and supernates were tested by HC, LA, and GS. For specimens reacting with the HPV 52/33/35/58 probe in the LA assay, type-specific PCR was performed for HPV types 52, 33, 35, or 58. Binomial proportions and kappa coefficients were calculated for agreement between assays. Cytology results and supernatant were available for 202 subjects. HPV detection increased with worsening cytologic abnormality in all three assays. For all cytologic groups, LA and GS detected more HPV (all and oncogenic) than HC. However, for detection of oncogenic HPV types represented in all three assays, differences between assays were less pronounced. The highest agreement was between LA and GS. In four of 12 specimens reacting with the HPV 52/33/35/58 probe in the LA assay but deemed HPV 52-LA-negative using an algorithm provided by the manufacturer, the presence of HPV 52 was confirmed using type-specific HPV 52 PCR. All four of these specimens were also GS-positive for HPV 52.

[Effectiveness of high frequency jet ventilation introduced immediately after cardiac surgery]

It is important to establish the lung protective strategy strictly for serious respiratory failure after cardiac surgery, because the hemodynamic state is unstable. High frequency jet ventilation (HFJV) was introduced in 5 patients with respiratory failure after cardiac surgery. Two had been diagnosed with acute aortic dissection and 3 with angina pectorlis. Off pump coronary artery bypass grafting was performed in 2 patients. Hemodynamic variables during HFJV were stable, and the duration of HFJV was 9 to 45 hours. Oxygenations improved immediately by the introduction of HFJV in all patients, and no adverse effect was recognized. Therefore, use of HFJV immediately after cardiac surgery might be an effective respiratory therapy of choice for patients with acute lung injury.

Re-evaluation of exercise intensity for overweight Japanese men by ventilatory threshold

AIM

To re-evaluate exercise intensity for overweight Japanese men by ventilatory threshold (VT).

METHODS

Cross sectional clinical intervention study.

SUBJECTS AND MATERIALS

One hundred and ten overweight Japanese men aged 32-59 years were recruited. The average body mass index was 28.5+/-2.5 kg/m(2). Aerobic exercise level was evaluated by measuring VT. Fifty per cent heart rate (HR) reserve by Karvonen's formula was calculated and compared with HR at VT. Fat distribution was evaluated by visceral fat and subcutaneous fat areas measured with computed tomography scanning at umbilical levels. Anthropometric parameters such as height, body weight and body fat percentage were also measured.

RESULTS

There was significant correlation between HR at VT and 50% HR reserve by Karvonen's formula (r=0.642, p<0.01). However, HR at VT was significantly lower than 50% HR reserve by Karvonen's formula (HR at VT 103.6+/-10.6 beat/min vs. 50% HR reserve 125.0+/-7.1 beat/min, p<0.01) and HR at VT was corresponded to 28.5+/-8.3% HR reserve by Karovonen's formula.

CONCLUSION

The present study indicated that exercise intensity of 30% HR reserve should be recommended for overweight Japanese men.

Changes in serum leptin concentrations in overweight Japanese men after exercise

AIM

To investigate the link between serum leptin concentrations and exercise.

DESIGN

Cross-sectional and longitudinal studies of an exercise intervention.

SUBJECTS

110 Japanese overweight men aged 32-59 years were recruited. At baseline, the average body mass index (BMI) was 28.5 +/- 2.5 kg/m2. From this group, we used data of 36 overweight men (BMI, 28.9 +/- 2.3) for a 1-year exercise programme.

MEASUREMENTS

Leptin was measured at baseline and after 1 year. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters, aerobic exercise level, muscle strength and flexibility were also investigated at baseline and after 1 year.

RESULTS

In the first analysis, using cross-sectional data, leptin was significantly correlated with total body fat (r = 0.760, p < 0.01), V (r = 0.383, p < 0.01) and S (r = 0.617, p < 0.01) areas. In the second analysis, using longitudinal data, leptin was significantly reduced after 1 year (pre 6.7 +/- 4.0 ng/ml vs. post 5.1 +/- 3.1 ng/ml, p < 0.01). Results showed that steps per day were increased, and aerobic exercise level, weight-bearing index (WBI) and insulin resistance were significantly improved. Although, there was a positive correlation between Delta leptin(positive changes in leptin after 1 year) and anthropometric measurements such as Delta body weight, Delta BMI and Delta body fat, leptin/body weight, leptin/BMI and leptin/body fat ratios were significantly reduced during exercise intervention.

CONCLUSION

The present study indicated exercise significantly lowers serum leptin concentrations, and thus it may improve the leptin resistance observed in overweight Japanese men.

[Preoperative autologous blood donation with cardiac surgery]

BACKGROUND

Preoperative autologous blood donation is commonly used to reduce exposure to homologous blood transfusions among patients undergoing elective cardiac surgery. The purpose of this study was to ascertain how much volume of predonated autologous blood need to avoid of homologous blood transfusion in cardiac procedure.

METHODS

One hundred twenty-eight patients underwent scheduled cardiac procedure between January 1998 and December 1999. Group 1: 400 ml predonated, operation without cardiopulmonary bypass (CPB) [n = 33], group 2: 800 ml predonated, operation without CPB (n = 23), group 3: 800 ml predonated, operation with CPB (n = 36), group 4: 1,200 ml predonated, operation with CPB (n = 36). Surgical procedures underwent only off-pump coronary artery bypass grafting (OPCAB) in groups 1 and 2. In groups 3 and 4 included coronary artery bypass grafting (CABG), valve replacement, CABG + valve replacement and atrial septal defect repair.

RESULTS

There were no significant differences in mean body weight, mean preoperative hematocrit values or mean volume of intraoperative blood loss between groups 1 and 2. There were no significant differences in mean age, mean body weight, mean preoperative and postoperative day-7 hematocrit values, mean volume of intraoperative blood loss or mean CPB time between groups 3 and 4. The mean postoperative day-7 hematocrit value was significantly lower in group 1 than in group 2. Homologous blood transfusion was avoided in 63.6% of those with predonation of group 1 versus 100% at group 2 (p < 0.05), 86.1% at group 3 versus 94.4% at group 4 (p < 0.05). In group 3, all patients who underwent redo operation or CABG + valve replacement needed homologous blood transfusion.

CONCLUSIONS

Autologous blood transfusion is effective for reducing the homologous blood requirement. It also seems that predonation of 800 ml may be sufficient to avoid homologous blood transfusion in cardiac surgery, however predonation of 1,200 ml is desirable in cases of redo operation or CABG + valve replacement.

Expression of p33(ING1) in hepatocellular carcinoma: relationships to tumour differentiation and cyclin E kinase activity

BACKGROUND

Inhibitor of growth-1 (ING1) is a new candidate for the tumour suppressor gene that encodes a 33k Da protein (p33(ING1)). While reduction of p33(ING1) is an important event in some human cancers, the expression of p33(ING1) in human hepatocellular carcinoma (HCC) remains to be examined. We evaluated p33(ING1) expression in various liver diseases including HCC.

METHODS

Expression of p33(ING1) was evaluated immunohistochemically not only in the normal liver (n = 5), but also in specimens of chronic hepatitis (n = 39) and HCC (n = 86). We also analysed the relationship between p33(ING1) expression and cyclin E kinase activity detected by autoradiography in 29 HCCs.

RESULTS

Expression of p33(ING1) was reduced in HCC, especially in moderately and poorly differentiated HCCs, and those at advanced stages. Furthermore, expression of p33(ING1) correlated inversely with cyclin E kinase activity.

CONCLUSIONS

These data suggest that reduction of p33(ING1) may contribute to the process of malignant transformation, progression and dedifferentiation of HCC via an increase of cyclin E kinase activity.

Long-term results after De Vega's tricuspid annuloplasty

BACKGROUND

Although some surgeons prefer to use artificial valve rings for tricuspid valve annuloplasty, we have mainly performed De Vega's tricuspid annuloplasty for functional tricuspid regurgitation, because it is a simple and effective technique for reducing tricuspid regurgitation due to annular dilatation. We evaluated long-term results of the De Vega's tricuspid annuloplasty up to 19 postoperative years.

METHODS

Between January 1980 and June 1999, 408 patients underwent De Vega's tricuspid annuloplasty. Long-term results after De Vega's tricuspid annuloplasty were analyzed.

RESULTS

There were 14 (3.4%) early deaths within 30 postoperative days. There were 63 (15.4%) late deaths during the follow-up period. The actuarial survival rate at 15 years after operation was 74.0%, the 15-year freedom from re-operation was 91.6%, and the 15-year freedom from all events was 58.7%, respectively.

CONCLUSIONS

These results suggest that De Vega's tricuspid annuloplasty was an effective and reliable procedure of choice for secondary tricuspid regurgitation with annular dilatation.

[Surgical angioplasty of isolated left coronary ostial stenosis]

A 42-year-old female had suffered from chest pain for approximately 1 month, and was admitted with unstable angina pectoris. Emergent coronary angiography showed an isolated 75% stenosis of the left coronary ostium. Repair of ostial stenosis by vein patch angioplasty was done by the transactional superior approach. Postoperative catheterization revealed an expanded left coronary orifice and the patient was discharged without any complications. We have experienced 2 other patients of isolated left coronary ostial stenosis, who had undergone double coronary artery bypass grafting. Long-term coronary angiography showed regression of ostial stenosis in 1 patient, and no progression of new lesions in either. These results suggest that direct vein patch angioplasty of the ostial lesion is an alternative procedure for isolated left coronary ostial stenosis.

Mitral valve replacement in ischemic mitral regurgitation. Preservation of both anterior and posterior mitral leaflets

BACKGROUND

The surgical risks associated with ischemic mitral regurgitation are thought to be greater than those for other forms of mitral regurgitation. We have performed mitral valve replacement using the St. Jude Medical bileaflet prostheses with preservation of both leaflets, along with all of the chordae tendineae and papillary muscles. The aim of this study was to retrospectively evaluate mitral valve replacement with preservation of both mitral valves with respect to long-term clinical results and left ventricular performance.

METHODS

Between January 1, 1988 and February 29, 2000, 15 patients were operated on for ischemic mitral regurgitation. There were 7 males and 8 females, and the mean age was 69.7+/-8.1 years. The preoperative variables showed clinical deterioration of the state, such as emergency operation in 40% of the patients, more than NYHA functional III class in 93% of patients, cardiogenic shock in 47% of the patients, a mean left ventricular ejection fraction of 36.8%, and a mean left ventricular end-systolic volume index of 116.7 ml/m2.

RESULTS

There were 5 (33.3%) hospital deaths during the follow-up period including 1 early death and 1 (10%) late death during the follow-up period. Thus, the actuarial survival rate after 5 years for the whole was 60%. However, the left ventricular dimensions and left ventricular fractional shortening, even if in patients with profound depressed left ventricular function preoperatively, showed maintenance of the cardiac function.

CONCLUSIONS

These results suggested that mitral valve replacement using the St. Jude Medical prostheses with preservation of both leaflets and all chordae tendineae and papillary muscles might be a procedure of choice for ischemic mitral regurgitation.

Helper T lymphocytes specific for cytokeratin 19 in patients with primary biliary cirrhosis

We demonstrated the expression of cytokeratin 19 (CK19) in biliary cells in chronic non-suppurative destructive cholangitis (CNSDC) and hypothesized that this expression may have a correlation with the disease process in addition to cellular immunity which is believed to be involved in the pathogenesis of primary biliary cirrhosis (PBC). It is, therefore, important to clarify whether the destruction of bile ducts and biliary cells are caused by cellular immunity including helper T lymphocytes (Ths) and cytotoxic T lymphocytes (CTLs) specific for CK19. We examined the existence of helper T lymphocytes specific for CK19 in patients with PBC. As a result, the frequencies of responders having CK19 specific helper T lymphocytes and the stimulation index (SI) of the proliferative responses of peripheral blood mononuclear cells (PBMCs) were significantly higher and larger in patients with PBC compared with those of patients with chronic hepatitis C and normal subjects. The phenotype of proliferating PBMCs specific for CK19 were predominantly CD4+ Th1 cells. The Th1 response may help the induction of CTLs specific for CK19, and these CTLs could attack biliary cells.

[A case of thrombosed St. Jude Medical valve 16 years after initial mitral valve replacement]

We report successful surgery for a thrombosed St. Jude Medical (SJM) valve 16 years after the initial mitral valve replacement even under conditions of satisfactory anticoagulation therapy. A 61-year-old-female had intermittent claudication and was admitted to our hospital for examination. The prosthetic valve sounds were normal to auscultation and the left ankle-pressure index was decreased to 0.6. Transthoracic echocardiography revealed no mitral regurgitation and a mean mitral valve gradient of 6-7 mmHg. Furthermore, transesophageal echocardiography revealed that one of the leaflets of the prosthetic valve was entirely immobilized at the closing position and a mobile soft tissue mass, 5 mm in diameter, was detected at the atrial side of the obstructed leaflet. Although 96,0000 IU of urokinase was administered intravenously for a week, we could not confirm any change in leaflet mobility. At the time of surgery, the posterior leaflet of the SJM valve, which was implanted at an anatomical orientation, was obstructed at the closing position with old and fresh thrombi. We decided upon replacement with a CarboMedics 29 M prosthetic valve. Postoperative medication consisted of warfarin plus low-dose aspirin. Generally, valve thrombosis occurs within 5 years after valve replacement. However, valve thrombosis is possible even in a reliable SJM valve and as long as 16 years after replacement. Therefore, the implantation of an SJM valve at an anti-anatomical orientation might lower the incidence of valve thrombosis in addition to life-long anticoagulation therapy.

Ascending aorta dissection associated with bicuspid aortic valve. Considerations 4 years after combined coronary artery bypass grafting and mitral valve replacement

Aortic dissection etiology involve many factors that are difficult to identify clearly. We report a 47-year-old man who underwent a Bentall operation with reattachment of bypass grafts for a dissecting aneurysm (DeBakey type II) 4 years after combined triple coronary artery bypass grafting and mitral valve replacement. This case appeared to be associated with factors leading to dissecting aneurysm although it remains unclear which was more influential congenital bicuspid aortic valve or proximal anastomosis of venous grafts or both. This case suggests the need to consider appropriate timing in surgical intervention for cases of congenital bicuspid aortic valves and the selection of additional aortic valve replacement in initial surgery.

Electromagnetic moments of the beta-emitting nucleus 16N

The nuclear magnetic dipole moment mu and electric quadrupole moment Q of the beta-emitting 16N(Ipi = 2(-), T(1/2) = 7.13 s) nucleus have been determined for the first time by detecting its beta-NMR in a MgO crystal and beta-NQR (nuclear quadrupole resonance) in a TiO (2) crystal to be /mu/ = (1.9859+/-0.0011) mu(N) and /Q/ = (17.9+/-1.7) mb, respectively. Although the prediction of mu given by the Hartree-Fock calculation agrees well with the experiment, an abnormally small effective charge for neutrons is required to account for the experimental Q.

[Preoperative autologous blood donation in elderly patients with cardiovascular surgery]

BACKGROUND

During the cardiovascular surgeries in elderly people, only a few cases can avoid the homologous blood transfusion, because of their preoperative anemic tendency and low hemopoietic abilities. We examined the capability to avoid the homologous blood transfusion in over 75 year old patients by the preoperative autologous blood collection. Sixty-six patients underwent scheduled cardiovascular surgery between January 1996 and December 1999. The groups were divided into three categories of preoperatively collected autologous blood amounts: high-amount (800-1,200 ml), medium-amount (200-800 ml), and low-amount (0 ml). Each group was divided into two subgroups in according to the use of cardiopulmonary bypass (CPB). There were no differences among the each group in age, body weight, or preoperative and postoperative day-7 hematocrit values.

RESULTS

Only 21.2% of patients could donate the expected blood amounts preoperatively. Mean volume was 641 ml. In groups used CPB, no patient was transfused homologous blood in high-amount group. On the contrary, 100% patients were donated in medium and low amount groups. In groups operated without CPB, homologous blood transfusion was required 14.3% in high-amount group, 25.0% in medium-amount group, and 83.3% in low-amount group.

CONCLUSION

It seems that predonation of more than 800 ml may be sufficient to avoid the homologous blood transfusion in using CPB operation and more than 400 ml in non using CPB operation.

How to spread out the satisfactory exposure: placement technique in right-sided maze procedure

We have, whenever possible, substituted cryoablation for incisions in the maze procedure. Cryoablation helps prevent massive bleeding because the number of resuturing sites is reduced and aortic cross-clamp time decreased. We are careful not to injure the atrio-ventricular conduction system during incision at the side of the Koch triangle or cryoablation while manipulating the atrial septum. In prior versions of the right-sided maze procedure, the IVC return cannula has obstructed the surgical field approaching the IVC and the tricuspid valve annulus. This report describes a new modification of maze procedure that includes changing the venous return site. We have obtained a satisfactory surgical field without being afraid of the anatomical pitfall, between the appendage and the tricuspid valve, and between the right coronary artery and the extended T incision. We studied 12 patients (8 males and 4 females, mean age 61 years) who underwent the maze procedure. Sinus rhythm was restored in 11 patients, whose clinical condition was improved to NYHA class I status. This technique has proven effective in obtaining satisfactory exposure of the-right atrium during the maze procedure.

Percutaneous cardiopulmonary support as a bridge to emergency operation--two surviving cases

Two patients had percutaneous cardiopulmonary support (PCPS) used as a bridge to emergency surgery. A 66-year-old man admitted with profound cardiogenic shock underwent direct stenting under PCPS with the diagnosis of acute myocardial infarction of the left main trunk, with the intention of performing revascularization as soon as possible. Subsequently, double coronary artery bypass grafting was successfully accomplished. A 69-year-old woman, admitted with acute heart failure due to critical aortic stenosis, manifested cardiogenic shock while undergoing catheterization. PCPS was immediately instituted until the acute deterioration of her hemodynamic state could be reversed, and was continued uneventfully till aortic valve replacement was performed. These results suggest that the current PCPS system is an effective response to acute circulatory collapse and will contributed to the improved survival of patients.

[Four cases of third time operation of coronary artery bypass grafting]

Reoperative coronary artery bypass operations are increasing in frequency. Consequently, an ever-increasing pool of patients now is being seen with need of coronary revascularization for repeated time. Four cases of second reoperation were retrospectively investigated. Until March 1999, 2,563 cases of isolated coronary artery bypass grafting were done at the Heart Institute of Japan, Tokyo Women's Medical University, Tokyo, Japan. Within those cases, 124 cases (4.8%) were reoperated. And among those 124 cases, 4 cases (3.2%) were secondly reoperated. There were one hospital death and two had a perioperative myocardial infarction. All of them needed intraaortic balloon pump support after operation. Three were discharged with relief of the symptoms. The average age at the primary operation was 51.1 years. All these cases, at the primary operation, no ITA graft was used. Two cases were incompletely revascularized, because of coronary arteries were ungraftable. Both at reoperation and at second reoperation, we are trying to make a complete revascularization by all arterial grafts. But because of limited number of arterial graft at repeated operation, all arterial complete revascularization is not done without difficulty. Therefore it is concluded that saphenous vein graft is still needed at repeated operation.

[Open heart surgery in three patients receiving dialysis for more than 20 years]

In Japan, the number of chronic hemodialysis (HD) patients is increasing, and there are 7,000 cases with a more than 20 year history of HD. At our institute, we have experienced 135 cases of open heart surgery in patients on HD, including 92 isolated CABG cases and 43 other open heart surgery cases. However, open heart surgery for patients with a more than 20 year history on HD is rare. Open heart surgery on HD patients is rather difficult, since perioperative management can be complicated and special care must be taken for prophylaxis of infection, fluid and electrolyte management and anticoagulation therapy. Many complications have been published in HD patients. At our institute, 3 cases of open heart surgery in patients with more than a 20 year history of HD have been performed. These included triple CABG, double CABG + AVR and double CABG in a post-kidney transplantation patient. They were discharged uneventfully with angiographically patent grafts. It is concluded that for CABG in patients on HD, aggressive use of arterial conduits for revascularization is recommended. For patients with a transplanted kidney, careful management against dysfunction and rejection is necessary.

[A successful surgical case of billowing mitral leaflet syndrome (Barlow syndrome) combined with severe mitral regurgitation]

We report a successful surgical case of billowing mitral leaflet syndrome combined with severe mitral regurgitation. A 45-year-old man suffered from congestive heart failure and admitted our institution for precise examination. A heart murmur was pointed out by a medical examination at his high school, and mitral valve prolapse was detected by echocardiography at 23 year of age. No medication was applied because he showed no symptom. From 44 year of age, he noted palpitation on exercise. Holter monitor showed blocked PAC and Wenckebach A-V block, and transesophageal echocardiography indicated severe mitral regurgitation due to the billowing of voluminous both leaflets. At his operation, we recognized the billowing of both leaflets with torn chordae, and size of the mitral valve orifice was 8.5 x 5 cm. The huge mitral valve was replaced with a CarboMedics 31M prosthetic valve by plicating mattress stitches of native mitral annulus. Histopathologic findings showed accumulation of acid mucopolysaccharide. Postoperative echocardiography showed reduction of the left ventricular volume and preservation of the left ventricular function. Relatively slow progression of the billowing mitral leaflet syndrome did not cause apparent symptoms of heart failure in this patient. Therefore, proper selection of the procedure and timing of surgical treatments might be important for successful long-term results after operation of the billowing mitral leaflet syndrome.

[A case report of total aortic reconstruction and choice of staged operation in Marfan syndrome]

A 37-year-old man with Marfan syndrome underwent four operations for extensive cardiovascular disease. He was diagnosed as having AAE, AR and DeBakey type I aortic dissection. First, Bentall operation using Piehler procedure and total aortic arch replacement using retrograde cerebral perfusion and profound hypothermia at 18 degrees C were performed on May 11, 1994. Second, repair of leakage of the right coronary artery anastomosis and grafting for the descending thoracic aortic aneurysm were performed on December 3, 1994. Y-type grafting for the AAA was performed on December 21, 1996. Last, grafting for TAAA was performed under hypothermia at a rectal temperature of 20 degrees C on November 17, 1997. This surgical strategy of staged operation for extensive cardiovascular disease in Marfan syndrome is an effective method. Regular follow-up by CT is necessary for deciding the time and method of reoperation.

[Efficacy of terminal warm blood cardioplegia in combination with Bretschneider-HTK solution for myocardial protection]

Many reports indicated that terminal warm blood cardioplegia (TWBC) was useful for reduction of the reperfusion injury in cardiac operations. We introduced Bretschneider-HTK solution (B-HTK) from April 1992, and combined use of the TWBC and the B-HTK was performed from May 1996. The purpose of this study was to evaluate clinical efficacy of the TWBC in combination with B-HTK for myocardial protection. In patient with valve operations from May 1995 to May 1997, clinical results were compared between the B-HTK with TWBC group (34 patients) and the B-HTK alone group (37 patients). Between two groups, there was no significant difference in patient characteristics, preoperative NYHA class, cardiopulmonary bypass time, aortic cross clamp time, minimum rectal temperature, rewarming and circulatory support time, incidence of IABP and blood concentration of max CPK, max GOT. Furthermore, the cardiac index in 1 postoperative day showed some trend to be higher in the combined TWBC group than that in the B-HTK alone group. But there was no significant difference between two groups in the LV shortening fraction at 14 postoperative day. Incidence of DC defibrillation was significantly lower in the combined TWBC group than that in the B-HTK alone group. These results suggested that combination of the TWBC might be useful for reduction of the reperfusion injury following myocardial protection with B-HTK solution.

[New screening method for coagulation abnormality including AT III deficiency during CABG]

In our institute, 1 ml of heparin is administered to the patients undergoing CABG before dissection and mobilization of the internal thoracic arteries (ITAs) and/or right gastroepiploic artery (GEA) to prevent possible thrombosis or coagulation tendency. Two patients with AT III deficiency underwent CABG and one of them died. The aim of this study is to know whether ACT check before and after administration of 1 ml of heparin is useful as a screening test of coagulation abnormalities including AT III deficiency. One hundred patients (84 males and 16 females) undergoing CABG were studied. Age ranged from 41 to 79 years (mean 64.8 +/- 8.0 years). One ml of heparin was administered to all the patients before ITAs and/or GEA were dissected and mobilized. ACT was doubly checked before (control ACT: c-ACT) and after (heparinized ACT: h-ACT) administration of heparin. ACT extension was defined as follows: ACT extension = (c-ACT)-(h-ACT). Mean c-ACT was 124 +/- 12 sec., h-ACT 188 +/- 26 sec. and ACT extension 64 +/- 24 sec. There were only 3 cases which ACT extension were less than 30 sec.: two of them were combined with AT III deficiency and the other was due to insufficient administration of heparin. In conclusion, examination of ACT after 1 ml administration of heparin is new, simple and convenient screening method for coagulation abnormalities including AT III deficiency during CABG.

Expression of bovine cytokines in Escherichia coli

Glutathione S-transferase fusion proteins of bovine interleukin-2 (IL-2), IL-4, IL-6 and interferon-gamma (IFN-gamma) were expressed in Escherichia coli. Complementary DNA (cDNA) for open reading frame of each cytokine without signal peptide encoding region was amplified by reverse transcriptional polymerase chain reaction method and was subcloned into pGEX-5X-1. In result, IL-6 and IFN-gamma fusion proteins in bacteria were soluble, but IL-2 and IL-4 fusion proteins were insoluble. The insoluble IL-2 fusion protein successfully refolded by urea became soluble. The recombinant IL-2, IL-6 and IFN-gamma could be obtained by the batch method using Glutathione Sepharose 4B and Factor Xa digestion, which may be useful for preparation of antisera as antigens and functional studies.

Effectiveness of transaortic venting from a failing left ventricle during venoarterial bypass

Insufficient unloading of the left ventricle (LV) is a limitation of percutaneous cardiopulumonary support (PCPS). We previously reported the unloading effect of transaortic catheter venting (TACV) during venoarterial bypass (VAB) in normal hearts. The aim of this study was to assess the effectiveness of TACV with VAB in a heart failure (HF) model. Seven adult mongrel dogs underwent TACV with VAB, and isolated LV failure was induced by multiple ligation of left coronary arteries. With standard hemodynamic monitoring, slope of the LV end-systolic pressure-volume relationship (Emax; mm Hg/ml), aortic elastance (Ea; mm Hg/ml), LV stroke work (SW; 10(-4)J), preload recruitable stroke work (PRSW; 10(-4)J/ ml), LV pressure-volume area (PVA; 10(-4)J), and potential energy (PE; 10(-4)J) were assessed using a micro-tip manometer and a conductance catheter. In addition to evaluation of LV function, myocardial adenosine 5'-triphosphate (ATP) was measured in each condition. The TACV combined support significantly reduced LV total energy (PVA) and LV work (SW). The LV energetic charge (PE/PVA, myocardial ATP) was significantly increased by TACV. These results suggest that TACV might be an effective technique for LV recovery during VAB or PCPS in patients with severe heart failure.

Lactobacillus casei inhibits antigen-induced IgE secretion through regulation of cytokine production in murine splenocyte cultures

BACKGROUND

Lactobacillus casei is a nonpathogenic gram-positive bacterium widely used in dairy products and has been shown to enhance the cellular immunity of the host.

METHODS

To examine the inhibitory effect of L. casei on IgE production, splenocytes obtained from ovalbumin (OVA)-primed BALB/c mice were restimulated in vitro with the same antigen in the presence of heat-killed L. casei. The effect of this bacterium on T helper (Th) phenotype development was also examined with naive T cells from OVA-specific T cell receptor-transgenic mice.

RESULTS

L. casei induced IFN-gamma, but inhibited IL-4 and IL-5 secretion, and markedly suppressed total and antigen-specific IgE secretion by OVA-stimulated splenocytes. The inhibitory effect of L. casei on IgE, IL-4, and IL-5 production was partially abrogated by addition of neutralizing antibody to IFN-gamma. Augmented IL-12 production was also observed in the cell cultures containing L. casei, and anti-IL-12 monoclonal antibody completely restored the IgE, IL-4, and IL-5 production to the control levels. The IL-12 augmentation by L. casei was macrophage-dependent. The Th cell development assay showed the ability of L. casei to induce Th1 development preferentially. This effect was also completely blocked by anti-IL-12 antibody.

CONCLUSIONS

This is the first demonstration that a nonpathogenic microorganism, L. casei, can inhibit antigen-induced IgE production through induction of IL-12 secretion by macrophages. The findings suggest a potential use of this organism in preventing IgE-mediated allergy.

[A case of the atrial dissociation after maze procedure: the coexistence of the sinus node potential and the focal atrial potential in high right atrium]

In a 58-year-old man, who was suffered from atrial fibrillation for a period of 20 years due to mitral stenosis and aortic valve regurgitation, mitral and aortic valve replacement and maze procedure were underwent. We have, whenever possible, substituted the cryoablation for the incision in the maze procedure in attempt to prevent massive bleeding. We found the oscillation of the baseline in lead I, II, III, aVL, aVF on postoperative surface electrocardiogram. We recognized the coexistence of 90/min sinus node potential and 375/min independent focal atrial potential in high right atrium (HRA) of intra-cardiac recording and only the sinus node potential in middle and lower right atrium of that. It was thought that the incision of maze procedure and cryoablation occurred to the atrial dissociation which coexisted segmental atrial fibrillation and sinus rhythm by electrophysiological block. In the postoperative electrophysiological study the sinus node automaticity and sinoatrial conduction were within normal limit and atrial tachycardia and atrial fibrillation were not induced. A wave of both atria was recognized in transesophageal echocardiography, though the segmental atrial fibrillation was left in a small region of HRA. It was supposed to be useful for maze procedure at the point of cardiac function, which included the maintenance of sinus rhythm with segmental atrial fibrillation, atrial kick and the recovery of the atrio-ventricular synchrony.

[A case of valve thrombosis of CarboMedics prosthesis four years after mitral valve replacement: relationship of anticoagulant therapy to coagulation and fibrinolysis activating factors]

A 50-year-old man experienced acute heart failure four years after initial mitral valve replacement (MVR) for left atrial thrombosis using a CarboMedics prosthesis, despite satisfactory coagulation control with warfarin. After initial MVR, late cardiac tamponade occurred twice and left circumflex branch stenosis was treated with percutaneous transluminal coronary angioplasty (PTCA). Re-MVR with an Edwards-TEKNA valve was performed after echocardiography and cineradiography showed mitral valve thrombosis, with thrombi on both mitral valve leaflets and covering most of the left atrial wall. Post-surgery progress was favorable with warfarin and dipyridamole therapy. After six weeks cardiac catheter revealed complete right external iliac artery occlusion. Cardiac dysfunction and atrial flutter apparently accelerated thrombosis after a common cold activated coagulation. Cardiac tamponade, circumflex branch stenosis, and right external iliac artery occlusion occurred despite satisfactory coagulation control by warfarin. Warfarin suppresses some coagulation factors but cannot always correct hypercoagulability. Two months after re-MVR, coagulation tests showed normal TT, F1 + 2, and D-Dimer but an increase in TAT, suggesting involvement of additional coagulation factors. After artificial valve replacement, therapy should achieve a PT-INR level of 3.0-4.5, with close follow-up using other indices of fibrinolysis and coagulation activity in addition to TT.

[A case report of a successful Redo Bentall operation]

An initial Bentall operation was performed on a patient aged 38 years with annuloaortic ectasia and aortic regurgitation. An echocardiogram and RI angiogram revealed a perigraft aortic aneurysm on the same patient aged 45 years. The aneurysm gradually developed and the maximum diameter reached 90 mm in size. The Redo-Bentall operation (Piehler modification) was successfully done once again on the same patient aged 56 years. The anastmosis between the right coronary orifice and the graft was detached on all sides. The anastmosis between the left coronary orifice and the graft was detached two thirds of all sides.

[One stage operation for ischemic heart disease and abdominal aortic aneurysm with ascending aortic calcification]

A 69-year-old man was referred to us with the diagnosis of abdominal aortic aneurysm (7 cm in diameter). Additionally his coronary arteriogram showed severe stenosis (LMT 75% and #6 99% delay). Because his ascending aorta was calcified severely, double CABG (LITA to LAD and RGEA to PL) was carried out in hypothermic ventricular fibrillation. Abdominal aortic aneurysm was replaced thereafter while the patient was still on cardiopulmonary bypass. His postoperative courses was satisfactory. In cases requiring early operation for both myocardial ischemia and abdominal aortic aneurysm, one stage operation was recommended. When atherosclerotic changes in the ascending aorta were severe, in situ arterial bypass grafting for ischemic heart disease under hypothermic ventricular fibrillation was useful.

[A modified Damus-Kaye-Stansel anastomosis for restrictive bulvoventricular foramen developed 5 years after Fontan procedure]

An one-year old girl, who had pulmonary artery (PA) banding and balloon atrioseptostomy done in the newborn period, underwent modified Fontan procedure on an emergency basis without cardiac catheterization, because of right heart failure. Echocardiogram showed no subaortic stenosis at Fontan procedure. Five years later, subaortic stenosis was documented with a 65 mmHg of ventricular-aortic pressure gradient at catheterization. A modified Damus-Kaye- Stansel (D-K-S) procedure was successfully performed using an end-to-end anastomosis of the distal aorta and a common stump, consisting of previously suture-closed main PA stump and the proximal aorta. At postoperative catheterization, the pulmonary valve was functioning well at LV outlet portion without regurgitation and stenosis. Significant subaortic stenosis may develop after Fontan procedure in patients with morphological narrowing without demonstrable pressure gradient. Such patients should have surgical intervention to the narrowing at the time of Fontan procedure. The modified D-K-S procedure can be an effective procedure to relieve subaortic stenosis after Fontan procedure.

[Effect of alpha and beta-adrenergic agonists on methacholine-induced nasal secretion in man]

To examine the roles of alpha-adrenergic, beta-adrenergic and cholinergic agonists on the nasal secretion mechanism, the author repeated nasal methacholine (Mch, 1 time 20 mg) challenges ten times at 10-min intervals in 13 healthy male subjects. As it was difficult to obtain a sufficient amount of nasal secretion for analysis using simple nasal provocation tests with alpha-and beta-adrenergic agonists before repeated Mch challenges, alpha-adrenergic (phenylephrine, Phe, 2 mg) and beta-adrenergic (isoproterenol, Iso, 0.2 mg) agonists were administered into both nostrils. The effects of these agents on the volume of nasal secretions (Vol), the fucose volume (Fu, an index of glandular secretion) and the albumin volume (Alb, an index of vascular permeability) in the Mch induced nasal secretions were analyzed each time. Repeated Mch challenges revealed that the initial challenge produced the largest response as reflected by the Vol, Fu and Alb of the secretions, and by Vol and Fu production being almost constant during the 10 repetitions of Mch challenge at 10-min intervals. However, Alb demonstrated the greatest decrements. Phe administration before Mch challenges gave rise to Fu increasing more markedly while Alb was unchanged. On the other hand, that of Iso before, produced greater decreases in Vol, Fu and Alb levels. Therefore, it is suggested that repeated Mch challenge causes the maintenance of glandular secretion while stopping albumin permeability, that with pre-administration of alpha-agonists glandular secretion increases, and that pre-administration of beta-agonists inhibits glandular secretion. When both alpha- and beta-agonists are given before the challenge, however, there is no increase in vascular permeability.

[Aortic valve replacement for rheumatoid aortic valve regurgitation]

Valve replacement for aortic regurgitation in patient with rheumatoid arthritis was rare in Japan. We report a successful case in which aortic regurgitation necessitated aortic valve replacement. A 62-year-old woman was admitted for shortness of breath, chest pain and progressive edema. She had been treated for rheumatoid arthritis for more than ten years using steroids. The aortic valve was successfully replaced by a prosthetic mechanical valve. The histopathological examination of the excised aortic valve demonstrated rheumatic nodules in the right- and non-coronary cusp. It was supported that these changes caused shrinkage of cusp and resulted in aortic regurgitation. This patient was discharged on the 20th postoperative day. There was no evidence of detachment of the prosthetic valve.

[Treatment of acute type A aortic dissection with onset of the right coronary insufficiency]

This is a case report of the successful treatment for acute type A aortic dissection with onset of the right coronary artery (RCA) obstruction due to compression of the dissected lumen. A 50-year-old man, who had been received medical therapy for hypertension for seven years, was admitted with profound cardiogenic shock. The ECG demonstrated complete A-V block and acute myocardial infarction (AMI) of right ventricle and inferior wall. Coronary catheter intervention was scheduled because intra-aortic balloon pumping was not effective, and arteriogram revealed aortic dissection, coronary insufficiency and aortic regurgitation (grade I). Soon after inflation of a perfusion catheter at the origin of RCA, elevation of arterial blood pressure and recovery to sinus rhythm were brought successfully by the coronary reperefusion. Replacement of the ascending aorta involving the intimal tear without surgical closure of RCA ostium, aortic valve resuspension and coronary artery bypass grafting with saphenous vein to RCA were performed 11 hours after the onset, and the postoperative course was uneventful. Although aortic dissection with onset of AMI was uncommon, it is suspected that the generalizing of catheter intervention for AMI increases awareness of such cases and it is emphasised that the application of perfusion catheter as an emergency procedure for the illness like this case is useful to preserve hemodinamic stability until the surgical treatment.

[A case of mitral regurgitation due to partial papillary muscle rupture whose etiology was unknown]

The etiology of the papillary muscle rupture includes myocardial infarction, trauma, hypertension, myxomatous degeneration, endocarditis etc. We report a case of partial papillary muscle rupture whose etiology was unknown, in a 77-year-old woman. The preoperative catheterization and coronary angiography showed severe mitral regurgitation and no significant coronary stenosis. And we recognized the mass waving into the left atrium in systole with the echocardiogram. At surgery, we repaired the mitral valve by resecting quadrangular areas of the posterior leaflet including the attachment of the torn papillary muscle. Additionally a number 28 Carpentier-Edwards mitral annuloplasty ring was sewn in place. In pathologic specimen, there were focal fibrosis, necrotic muscle, lymphocytes, and no vegetation.