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Recent gastric cancer reports have shown that preoperative sarcopenia worsens long-term prognosis after gastrectomy. We investigated the impact of laparoscopic surgery on the long-term prognosis of locally advanced gastric cancer patients with sarcopenia. This retrospective study included consecutive patients who underwent radical gastrectomy for primary c-stage II or III advanced gastric cancer, between April 2008 and April 2017, with computed tomography records of skeletal muscle mass. The skeletal muscle mass index was calculated, and sarcopenia was defined when values were below the cut-off. The patients were divided into a laparoscopy group and open group, in which the background was adjusted using propensity score matching; the relapse-free survival and overall survival were compared between them. The prognostic factors for relapse-free survival and overall survival were investigated by multivariate analyses. This study included 141 patients with sarcopenia (laparoscopy group, n = 69 [48.9%]; open group, n = 72 [51.1%]). After matching, there were 50 patients in both groups, with no significant differences in patient background. The median follow-up period was 38 months. Relapse-free survival was worse in the open group (hazard ratio: 1.662, 95% confidence interval: 0.910–3.034; P = 0.098), but there was no difference in the overall survival (P = 0.181). Multivariate analysis concluded that open surgery is an independent prognostic factor of relapse-free survival (hazard ratio: 3.219, 95% confidence interval: 1.381–7.502; P = 0.007) but not of OS. Compared with the open surgery group, the laparoscopy group had a better RFS, although the difference was not statistically significant.

Summary Background & aims It has been reported that skeletal muscle mass loss during adjuvant chemotherapy and preoperative reduced skeletal muscle mass are associated with discontinuation of adjuvant chemotherapy. However, the relationship between visceral fat mass and compliance has not yet been investigated. In this study, we clarified the impact of low preoperative visceral fat mass on compliance and relapse-free survival (RFS) in gastric cancer patients. Methods This was a retrospective cohort study of consecutive patients with gastric cancer who underwent radical gastrectomy for pathological stages II and III, and who received postoperative S-1 adjuvant chemotherapy between April 2008 and April 2017. Treatment failure was defined as discontinuation of adjuvant chemotherapy within 1 year. Visceral fat mass was measured preoperatively at the umbilical level on computed tomography, which was divided by height (m2) to obtain the visceral adipose tissue index (VAI). Patients with a VAI below the median cut-off value were categorized as low-VAI, while those above the cut-off value were classified as high-VAI. We compared the treatment failure rate and RFS in the low-VAI and high-VAI groups after adjusting for group differences with propensity score matching. In addition, risk factors related to treatment failure and poor prognostic factors for RFS were analyzed in multivariate analyses that included all cases. Results Among all 263 patients, treatment failure and recurrence were observed in 44 patients (16.7%) and 90 patients (34.2%), respectively. The median follow-up period was 52 months. After propensity matching, there were 101 patients in both low -and high-VAI groups. Treatment failure rate was higher (P = 0.037) and RFS was worse (P = 0.025) in the low-VAI group. In multivariate analyses, low-VAI was an independent risk factor associated with treatment failure (odds ratio (OR): 2.360, 95% CI: 1.120–5.000, P = 0.025), and was a poor prognostic factor for RFS (hazards ratio (HR):1.652, 95% CI: 1.057–2.582, P = 0.028). Conclusions Preoperative low visceral fat mass was an independent risk factor for poor compliance with adjuvant chemotherapy and a poor prognostic factor for RFS after radical gastrectomy in gastric cancer patients. Preoperative evaluation using body composition may be useful for post-treatment and prognosis prediction.

Introduction Single-incision laparoscopic gastrectomy can be difficult because of complex instrumentation and a limited working angle. We standardized a needle device-assisted single-incision laparoscopic gastrectomy (NA-SILG) procedure for early gastric cancer in 2013. Herein, we present our technique and evaluate it in comparison to the conventional laparoscopic gastrectomy CLG) technique. Methods We retrospectively reviewed medical records of 149 patients who underwent a NA-SILG or distal (CLG) for early gastric cancer between January 2013 and August 2016. We performed 1:1 propensity score matching between the two groups. Results Eighteen patients who underwent a NA-SILG and 131 who underwent a CLG were included. Almost all patients were in clinical stage IA. Operative times were 216 ± 29.7 minutes and 220 ± 51.7 minutes for the NA-SILG and CLG groups, respectively; the median intraoperative bleeding amounts were 5 mL and 10 mL for the NA-SILG and CLG groups, respectively. The median number of retrieved lymph nodes was 41.5 and 57 for the NA-SILG and CLG groups, respectively. The number of patients needing analgesics was significantly lower in the NA-SILG group (P = .003) than in the CLG group. Neither group had postoperative complications more severe than Clavien-Dindo classification III. Conclusion Needle device-assisted SILG is safe and feasible for early gastric cancer treatment in slim figure patients. It has short and long-term outcomes comparable to the CLG but is less invasive and results in less postoperative pain.

The aim of this study was to examine the effects of a decrease in visceral adipose tissue on the long-term outcomes of patients with gastric cancer after surgery.This single-institution, retrospective study included a cohort of 485 patients who underwent gastrectomy for P-T2 (MP; or a more advanced gastric cancer) from April 2008 to April 2018. The preoperative visceral adipose tissue area and the skeletal muscle area were measured on computed tomography images. The areas were divided by height (mOf the 485 patients, 243 (50.1%) were in the low-VAI group and 242 (49.9%) were in the high-VAI group. For overall survival, the low-VAI group, compared with the high-VAI group, had a significantly poorer prognosis (P0.001). Multivariate analysis indicated that both low VAI (hazard ratio [HR], 1.666; 95% confidence interval [CI], 1.127-2.461; P = 0.010) and low SMI (HR, 1.467; 95% CI, 1.057-2.035; P = 0.022) were independent prognostic factors.Both loss of preoperative skeletal muscle mass and a decrease in visceral adipose tissue have an effect on the long-term outcomes of advanced gastric cancer.

Introduction The indication of laparoscopic gastrectomy for advanced cases such as serosal invasion or peritoneal dissemination is still controversial. We report the clinical experiences of laparoscopic diagnosis with image enhancement and autofluorescence (AF) systems for laparoscopic gastric cancer surgery. Methods The image enhancement system was introduced to 164 patients who underwent laparoscopic gastric cancer surgery as the AF group. The control group was defined as 165 cases who underwent bright light observation without the image enhancement system. The operative findings were recorded during surgery. All image findings were retrospectively compared with the pathological findings. Furthermore, the relationship between the image and pathological findings for peritoneal dissemination and subserosal invasion was evaluated. Results This study included 329 patients, divided into the control group of 165 patients (50.2%) and the AF group of 164 patients (49.8%). There was no statistically significant difference in patient background between the two groups. In seven cases of peritoneal dissemination, AF was positive, and macroscopic abnormal vascularization was detected. The sensitivity, specificity, and positive and negative predictive values were 100%, 99.4%, 87.5%, and 100%, respectively. In 29 cases of serosal invasion, AF was positive, and macroscopic abnormal vascularization was detected. In the detection accuracy of subserosal invasion, the sensitivity, specificity, and positive and negative predictive values were 75.7%, 97.6%, 90.3%, and 93.2%, respectively. Conclusion The image enhancement with the AF system is useful for the laparoscopic intraoperative diagnosis of serosal invasion and peritoneal dissemination for advanced gastric cancer.

Buckling-restrained braces (BRBs) achieve large peak and cumulative ductility capacities by restricting yielding to an encased core, while maintaining global stability. However, stability is often governed by the connections and is sensitive to the end fixity provided by the adjacent framing and gusset, and flexural continuity between the neck and restrainer. This paper presents simple analytical methods to determine the flexural properties of these key components. Full-depth gusset stiffeners are found to be highly effective in increasing the out-of-plane rotational stiffness (KRg), equivalent to doubling the thickness. An equivalent connection is proposed to account for the adjacent framing (KRf), but this may be neglected if KRf > 10∙KRg. This is typically satisfied if a diaphragm slab and transverse beam are provided, but may exceed beam torsional bracing requirements. The restrainer end moment transfer capacity is extended to mortar-filled RHS restrainers, confirming that neck insert ratios of Lin/Bn > 2.0 are required for full continuity.

When a buckling-restrained brace (BRB) is composed of a flat steel core encased in a rectangular steel tube with infill mortar, the flat steel core develops high-mode buckling waves within the spaces occupied by compressible debonding layers when BRB is in compression. The wave crests and troughs collide with mortar and then acting outward forces on restrainer. The steel tube wall may bulge out if the restrainer is too weak to sustain the outward forces and the BRB may lose its compression carrying capability. The outward force can be estimated according to steel core high-mode buckling wavelength and the debonding layer thickness. The restrainer capacity in resisting outward forces can be estimated by using the upper bound theory in plastic analysis. The results of 39 BRB tests were compared in order to evaluate the effectiveness of steel tube capacity estimation methods. 24 BRBs exhibiting local bulging failure suggested that the steel tube capacity can be estimated by assuming the bulged wall as a wedge shape with five of its boundary developing flexural strength. The proposed estimation is conservative and can be adopted for BRB design in preventing local bulging failure for severe seismic services.

The 2011 Tohoku Earthquake ruptured multiple faults simultaneously, generating strong ground motions over a long duration at long periods. Such severe events have recently begun to be considered in structural design, requiring explicit calculation of the low cycle fatigue capacity and fracture point. This paper presents a numerical study of dual moment and braced frames, with either conventional or buckling-restrained braces. Both brace and beam end fracture is considered, and incremental dynamic analysis (IDA) used to determine the ultimate failure mechanism under extremely large ground motions. Fragility curves are generated, demonstrating the significant role that member fracture has on the seismic performance of braced frames.

This paper introduces a grid-purlin system, which was composed of secondary rectangular-hollow-section grids welded onto the top flange of I-shaped beams of moment frames. The welded grid-purlin itself may play a role of a lateral bracing member for the welded beam. However, the ultimate strength, plastic rotation capacity, or other structural characteristics of this grid-purlin system remain poorly understood. This paper presents two full-scale cyclic loading tests on specimens with I-shaped beams 700 mm deep, 240 mm wide, and 13 m long. The diagonal length of grids in the square grid-purlin of the specimen was 1.3 m on-center, and two different depths of the sections were selected for the purlin sections. Both specimens successfully achieved fully plastic moments at a plastic rotation exceeding 0.04 rad. This shows that the grid-purlin system provides reliable lateral bracing. Continuum finite-element (CFE) analysis was performed to simulate the hysteretic experimental response of the grid-purlin system. This CFE model was used to examine the plastic rotation capacity for a variety of combinations of I-shaped beams and grid-purlins.

A controlled spine frame system consisting of an elastic moment frame, elastic spine frame and concentrated yielding elements is proposed to ensure continuous usability of buildings in the event of an earthquake exceeding the design level. Prior studies have documented the excellent performance of spine frame structures in preventing both the concentration of damage in soft stories as well as in providing self-centering. The current study develops a simplified design method based on equivalent dual multi-degree-of-freedom and single-degree-of-freedom representations, discussing the effects of damper yield drift, and stiffness ratios between the elastic moment frame, spine frame, and dampers on the structural response. This design method is validated with a parametric study and optimal ranges of the stiffness ratios are provided.

This paper presents the design and experimental investigation of a miniature buckling-restrained brace (MBRB) which can act as a hysteretic damper to dissipate energy when subjected to inelastic axial deformations. The MBRB is similar to a buckling restrained brace (BRB) with a yielding steel core plate restrained from buckling by a grouted restraining tube. The MBRBs, however, are designed to have shorter lengths, smaller steel core dimensions, and smaller yield capacity as compared to a typical BRB. As a result, careful consideration is required for the detailing at the ends and the stability of the MBRB. Small capacity BRBs can be useful in a range of applications as a primary energy dissipating structural fuse or supplementary axial hysteretic damper in seismic force resisting systems. The design, construction, and testing of six MBRB specimens with nominal axial yield forces between 30 kN and 95 kN are reported. Issues related to global stability of the MBRBs are discussed and a stability criterion to prevent global buckling was adopted to design the MBRB end connection pieces. The MBRBs exhibited cumulative plastic deformations between 181 and 400 times the yield deformation and cumulative plastic strain between 46% and 106%. Conclusions about the behavior and recommendations for the design of the MBRB are presented.

Summary One of the key limit states of buckling-restrained braces (BRBs) is global flexural buckling including the effects of the connections. The authors have previously proposed a unified explicit equation set for controlling the out-of-plane stability of BRBs based on bending-moment transfer capacity at the restrainer ends. The proposed equation set is capable of estimating BRB stability for various connection stiffnesses, including initial out-of-plane drift effects. However, it is only valid for symmetrical end conditions, limiting application to the single diagonal configuration. In the chevron configuration, the out-of-plane stiffness in the two ends differs because of the rotation of the attached beam. In this study, the equation set is extended to BRBs with asymmetric end conditions, such as the chevron configuration. Cyclic loading tests of the chevron configuration with initial out-of-plane drifts are conducted, and the results are compared with the proposed equation set, which is formulated as a function of the normalized stiffness of the attached beam. © 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd. © 2016 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.

A controlled spine frame system consists of moment frames and spine frames with concentrated energy-dissipating members. This system guarantees the continuous usability of buildings against Japanese Level-2 earthquake events (similar to DBE events in California), and the authors have confirmed its excellent performance in preventing damage concentration in low-rise buildings. This study further investigates the effect of diverse structural properties on the seismic performance of controlled spine frames applied in high-rise buildings. The effect of building height, yield drift of dampers, spine-to-moment frame stiffness ratio, and damper-to-moment frame stiffness ratio are illustrated in detail, and optimal values are discussed. Also, a segmented spine frame system is proposed for high-rise buildings. The simple evaluation procedure proposed by the authors for low-rise buildings, based on equivalent linearization techniques and response spectrum analyses, was modified to include higher-mode effects for high-rise buildings based on modal analysis. The modified evaluation method was verified by modal pushover and time-history analyses.

Although passive response control design is a popular method, an arrangement methodology for energy-dissipating devices in spatial structures has not been established yet. In this study, optimization techniques are applied to arrangements of energy-dissipating devices in truss tower structures. First, a response prediction rule using the response spectrum and the equivalent linearization method is proposed. Then, a genetic algorithm is applied to select the optimal arrangement of viscoelastic damper devices in truss tower structures. Additionally, the device arrangements determined by empirical design methods are compared with the optimal solutions.

Existing RC buildings conforming to relatively older regulations and codes may lack in seismic resistance. This is especially true for public buildings such as schools or hospitals, which demand efficient retrofitting to ensure safety during and after a seismic event. Although retrofit design with conventional braces (CB) has been practiced for decades, the unbalanced hysteresis behavior of CBs tends to result in damage concentrated in specific stories. Buckling-restrained braces (BRBs), a new generation of bracing system, may increase structural integrity and at the same time reduce seismic response in a building via energy absorption. However, when the maximum story drift exceeds the yield point of RC frame, all structural elements including BRBs lose horizontal stiffness, which may result in both damage at a specific story and residual deformation effects occurring after an earthquake. Therefore, BRBs may be applied to such buildings using elastically designed steel frames (SF).This paper discusses the evaluation of damage distribution and self-centering functions of the elastic steel frames that connect BRBs to RC frames. In addition, we propose a simplified method based on equivalent linearization to design the required amount of BRB and elastic SF capacity for retrofitting existing RC buildings. The results were confirmed by nonlinear time-history analysis using high-intensity seismic waves. The results show that RC buildings retrofit with BRBs respond as predicted by the proposed method and target story drift is obtained. The story drifts of the BRB retrofit model is significantly reduced relative to both the original building and the building retrofit with CBs. In addition, because BRBs are attached to an existing building by elastically designed steel frames, the significant effect of SF on the reduction of residual displacements was also shown and discussed.

SUMMARY Buckling-restrained braces (BRBs) are widely used as ductile seismic-resistant and energy-dissipating structural members in seismic regions. Although BRBs are expected to exhibit stable hysteresis under cyclic axial loading, one of the key limit states is global flexural buckling, which can produce an undesirable response. Many prior studies have indicated the possibility of global buckling of a BRB before its core yields owing to connection failure. In this paper, BRB stability concepts are presented, including their bending-moment transfer capacity at restrainer ends for various connection stiffness values with initial out-of-plane drifts, and a unified simple equation set for ensuring BRB stability is proposed. Moreover, a series of cyclic loading tests with initial out-of-plane drifts are conducted, and the results are compared with those of the proposed equations. © 2013 The Authors. Earthquake Engineering & Structural Dynamics published by John Wiley & Sons Ltd.