Masakazu Ikenaga

National Hospital Organization Kumamoto Medical Center, Kumamoto-shi, Kumamoto Prefecture, Japan

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Publications (5)17.91 Total impact

  • Article: Value of general surgical risk models for predicting postoperative liver failure and mortality following liver surgery.
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    ABSTRACT: BACKGROUND AND OBJECTIVES: This study evaluated the ability of general surgical models to predict postoperative morbidity and mortality in liver surgery. METHODS: The postoperative course and mortality rates predicted by general surgical models were investigated in 960 patients who underwent hepatectomy or ablation therapy for primary or metastatic liver carcinoma. RESULTS: The area under the receiver operative characteristic curve (95% confidence intervals) for detecting postoperative liver failure was 0.89 (0.84-0.94), 0.85 (0.78-0.92), and 0.78 (0.72-0.85) for the Estimation of Physiologic Ability and Surgical Stress (E-PASS) model, the modified E-PASS (mE-PASS) model, and the Portsmouth Physiologic and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) model, respectively, and those for detecting in-hospital mortality were 0.85 (0.76-0.93), 0.85 (0.78-0.92), and 0.79 (0.71-0.87), respectively. Nevertheless, all of the models overpredicted the overall mortality rate (by 2.3-fold for E-PASS, 2.3-fold for mE-PASS, and 2.9-fold for P-POSSUM). CONCLUSIONS: The general surgical risk models demonstrated high discriminatory power for predicting postoperative outcomes in liver surgery, but overpredicted the overall mortality rate by more than twofold. Therefore, these models should be refined to make them more suitable for predicting liver surgery outcomes. J. Surg. Oncol © 2012 Wiley Periodicals, Inc.
    Journal of Surgical Oncology 05/2012; · 2.10 Impact Factor
  • Article: Evaluation of modified estimation of physiologic ability and surgical stress in colorectal carcinoma surgery.
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    ABSTRACT: We recently modified Estimation of Physiologic Ability and Surgical Stress, our prediction scoring system. This study evaluated the usefulness of our modified version for colorectal carcinoma in comparison with existing models. This investigation studied a multicenter cohort. The study was conducted in regional referral hospitals in Japan. Patients were included who underwent elective surgery for colorectal carcinoma. Postoperative morbidity, mortality, and predicted mortality rates for original and modified Estimation of Physiologic Ability and Surgical Stress were investigated in 2388 patients in comparison with existing European models. Among the models, the modified Estimation of Physiologic Ability and Surgical Stress demonstrated the highest discriminatory power in terms of in-hospital mortality (area under receiver operating characteristic curve: 0.84 for Estimation of Physiologic Ability and Surgical Stress, 0.87 for modified Estimation of Physiologic Ability and Surgical Stress, 0.84 for Portsmouth modification of POSSUM, 0.74 for ASA status-based model), as well as 30-day mortality (area under receiver operating characteristic curve: 0.82 for Estimation of Physiologic Ability and Surgical Stress, 0.84 for modified Estimation of Physiologic Ability and Surgical Stress, 0.81 for POSSUM, 0.78 for colorectal POSSUM, 0.76 for Association of Coloproctology of Great Britain and Ireland score). British models, in general, overpredicted postoperative mortality rates by more than 10 times. The current study analyzed only the Japanese population treated in medium-volume centers. Among the models, modified Estimation of Physiologic Ability and Surgical Stress was the most accurate in predicting postoperative mortality in colorectal carcinoma surgery. These findings should be validated in Western populations, because the Japanese population may differ from Western populations in terms of body shape or reserve capacity.
    Diseases of the Colon & Rectum 10/2011; 54(10):1293-300. · 3.13 Impact Factor
  • Article: Evaluation of modified Estimation of Physiologic Ability and Surgical Stress in gastric carcinoma surgery.
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    ABSTRACT: We recently modified our prediction scoring system "Estimation of Physiologic Ability and Surgical Stress" and have designated the current version mE-PASS. This scoring system has been designed to obtain predicted postoperative mortality rates before surgery and this study was performed to assess its usefulness in elective surgery for gastric carcinoma. We investigated seven variables for mE-PASS and evaluated the postoperative course in 3,449 patients who underwent elective surgery for gastric carcinoma in Japan between August 20, 1987 and April 9, 2007, in order to quantify the predicted in-hospital mortality rates (R). The calibration and discrimination power of R were assessed using the Hosmer-Lemeshow test and the area under the receiver operating characteristic curve (AUC), respectively. The ratios of observed-to-estimated mortality rates (OE ratios) were quantified as a measure of quality. The overall postoperative morbidity and mortality rates were 19.0 and 2.0%, respectively. R demonstrated good power in calibration (χ(2) value, 12.5; df 8; P = 0.89) as well as discrimination (AUC, 95% confidence intervals: 0.80, 0.75-0.85). The OE ratios between hospitals ranged from 0.44 to 1.8. Overall, the OE ratios seemed to improve with time (OE ratio, 95% confidence intervals: 1.3, 0.73-2.4 for the early period between 1987 and 2000; 1.0, 0.59-1.7 for the middle period between 2001 and 2004; and 0.65, 0.36-1.2 for the late period between 2005 and 2007). Based on these findings, mE-PASS might be useful for medical decision-making and for assessing the quality of care in elective surgery for gastric carcinoma.
    Gastric Cancer 05/2011; 15(1):7-14. · 2.42 Impact Factor
  • Article: A multicenter prospective study of surgical audit systems.
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    ABSTRACT: This study was undertaken to evaluate a modified form of Estimation of Physiologic Ability and Surgical Stress (E-PASS) for surgical audit comparing with other existing models. Although several scoring systems have been devised for surgical audit, no nation-wide survey has been performed yet. We modified our previous E-PASS surgical audit system by computing the weights of 41 procedures, using data from 4925 patients who underwent elective digestive surgery, designated it as mE-PASS. Subsequently, a prospective cohort study was conducted in 43 national hospitals in Japan from April 1, 2005, to April 8, 2007. Variables for the E-PASS and American Society of Anesthesiologists (ASA) status-based model were collected for 5272 surgically treated patients. Of the 5272 patients, we also collected data for the Portsmouth modification of Physiologic and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) in 3128 patients. The area under the receiver operative characteristic curve (AUC) was used to evaluate discrimination performance to detect in-hospital mortality. The ratio of observed to estimated in-hospital mortality rates (OE ratio) was defined as a measure of quality. The numbers of variables required were 10 for E-PASS, 7 for mE-PASS, 20 for P-POSSUM, and 4 for the ASA status-based model. The AUC (95% confidence interval) values were 0.86 (0.79-0.93) for E-PASS, 0.86 (0.79-0.92) for mE-PASS, 0.81 (0.75-0.88) for P-POSSUM, and 0.73 (0.63-0.83) for the ASA status-based model. The OE ratios for mE-PASS among large-volume hospitals significantly correlated with those for E-PASS (R = 0.93, N = 9, P = 0.00026), P-POSSUM (R = 0.96, N = 6, P = 0.0021), and ASA status-based model (R = 0.83, N = 9, P = 0.0051). Because of its features of easy use, accuracy, and generalizability, mE-PASS is a candidate for a nation-wide survey.
    Annals of surgery 01/2011; 253(1):194-201. · 7.90 Impact Factor
  • Article: Prediction of anastomotic leak and its prognosis in digestive surgery.
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    ABSTRACT: Anastomotic leak (AL) is a dangerous postoperative complication in gastrointestinal surgery. The present study focuses on whether our prediction scoring system, "Estimation of Physiologic Ability and Surgical Stress" (E-PASS), could predict occurrence of AL and its prognosis in various kinds of gastrointestinal surgical procedures. We prospectively investigated parameters of E-PASS, absence or presence of AL, and in-hospital mortality in 6,005 patients who underwent elective digestive surgery with alimentary tract reconstruction in 45 acute care hospitals in Japan between 1 April 2002 and 31 March 2007. Incidences of AL were 19.6% for esophagectomy via right thoracotomy and laparotomy, 11.7% for pancreaticoduodenectomy, 7.4% for low anterior resection, 4.0% for total gastrectomy, 1.8% for open distal gastrectomy, 1.3% for open colectomy, for an overall incidence of 4.1%. The incidence in each procedure significantly correlated with median value of surgical stress score of the E-PASS (R = 0.78, n = 11, p = 0.0048). The incidences of AL increased when Total Risk Points (TRP) of the E-PASS increased; 1.1% at the TRP range of <500, 2.8% at 500 to <1,000, 4.8% at 1,000 to <1,500, and 13.6% at ≥ 1,500 (p < 0.0001). In patients who suffered from AL, an in-hospital mortality rate at TRP < 1,000 was significantly lower than that at TRP of ≥ 1,000 (1.1 vs. 15.9%; p = 0.00019). The E-PASS, requiring only nine variables, may be useful in predicting AL and its prognosis.
    World Journal of Surgery 12/2010; 35(4):716-22. · 2.36 Impact Factor