Learning curve of robotic distal and total gastrectomy.

BACKGROUND: This study aims to assess the learning curve of robotic distal gastrectomy (RDG) and robotic total gastrectomy (RTG) for gastric cancer. METHODS: Data on consecutive patients who underwent robotic gastrectomy for gastric cancer by five surgeons between March 2010 and August 2019 at two high-volume institutions were collected. The learning curve was determined based on the analyses of operation time and postoperative complications within 30 days. Cumulative sum analysis (CUSUM) and risk-adjusted-CUSUM (RA-CUSUM) were applied to identify the turning points (TPs). RESULTS: A total of 899 consecutive patients were included. The mean number of patients needed to overcome the learning curve for operation time of RDG and RTG were 22 and 20, respectively. The number of patients needed to overcome the learning curve for postoperative complications after RDG and RTG were 23 and 18, respectively. The surgical outcomes in the post-TP group were better than in the pre-TP group and improved as surgeons' experience increased. Also, increased case numbers in RDG promoted the RTG learning process. CONCLUSION: The present study demonstrated a substantial influence of surgical cumulative volume on improved surgical outcomes in robotic gastrectomy. Increased experience in RDG may help surgeons to achieve proficiency faster in RTG.

Short-term outcomes of pelvic floor peritoneum closure in endoscopic low anterior resection of rectal cancer: A propensity score matching analysis.

BACKGROUND: The efficacy of pelvic floor peritoneum closure (PC) during endoscopic low anterior resection (E-LAR) of rectal cancer remains unclear. This study aimed to clarify whether pelvic floor PC affected short-term outcomes. METHODS: The study group comprised patients with the pathologically confirmed diagnosis of rectal cancer who underwent E-LAR with pelvic floor PC or with no PC (NPC) between January 2013 and December 2018 in Southwest Hospital. After propensity score matching (PSM), 584 patients (292 who underwent PC and 292 who underwent NPC) were evaluated. Postoperative indicators, including the rates of complications, anastomotic leakage (AL), reoperation, and inflammation, were observed in the two groups. RESULTS: No significant difference was observed in the rates of postoperative complications between the PC and NPC groups. The rates of AL were similar (11.3% vs. 9.2%, p = .414). However, the reoperation rate of patients in the PC group was significantly lower than that of patients in the NPC group after AL (36.4% vs. 11.1%, p = .025). The hospital costs were higher in the NPC leakage subgroup (p = .001). Additionally, the serum C-reactive protein levels were lower in the PC group on postoperative days (PODs) 1, 3, and 5, whereas procalcitonin levels on POD 1 and 3 were lower in the PC group but did not differ significantly on POD 5. CONCLUSION: Pelvic peritonization did not affect the rate of complications, especially AL; however, it effectively reduced the reoperation and inflammation rates and reduced hospitalization costs. Other short-term outcomes were similar, which warrant the increased use of pelvic peritonization in endoscopic surgery.

Identification of a giant mediastinal teratoma by echocardiography: A case report.

The diagnosis of mediastinal space-occupying lesions largely relies on X-ray and computed tomography. However, thanks to technological progress, transthoracic echocardiography can clearly display the mediastinal structures surrounding the heart and great vessels, thereby improving the detection rate of mediastinal space-occupying lesions. Primary mediastinal teratoma is relatively rare, and removal of giant mediastinal teratoma by thoracoscopic surgery has rarely been reported. Here, we report a case of giant mediastinal teratoma diagnosed by transthoracic echocardiography, which was treated by complete thoracoscopic resection and confirmed by histology.

Surgery strategy of 13 cases to control bleeding from the liver on laparoscopic repeat liver resection for recurrent hepatocellular carcinoma.

INTRODUCTION: Laparoscopic repeat liver resection (LRLR) is a safe and effective treatment in recurrent hepatocellular carcinoma (rHCC) in particular patients. However, there are less reports about surgery strategy of LRLR for rHCC. The aim of this study was to perform a systematic strategy for bleeding of liver to increase the safety and feasibility of LRLR for rHCC. METHODS: In this study, a total of 13 cases of LRLR for rHCC, including 8 males and 5 females; aged 28-72 years, mean age 54 years, who were received at least one laparotomy due to HCC. We employ to block the local blood flow, ligation of the left or right hepatic artery and/or approach of Pringle according to the assessment of the degree of adhesions in the abdominal and the first hepatic portal, the location of the tumour (edge/central). RESULTS: Three cases were less adhesions, nine cases were dense adhesions but 1 case was serious adhesions. Two cases were employed to block the local blood flow, 3 cases were employed to ligation of the left or right hepatic artery and 7 cases were employed to approach of Pringle. Twelve cases were successfully completed by LRLR whereas 1 case was completed by transfer to the open resection, including massive resection in 3 cases (the diameter of resection ≥3 cm), small hepatectomy in 10 cases (the diameter of resection <3 cm), no severe perioperative complication. The average operative time was (142 ± 34) min, the average intraoperative blood loss was (251 ± 92) ml and the average post-operative hospital time was (9 ± 3) d. The mean follow-up time was 25 months. Until the last follow-up, 11 cases survived while 2 cases died because of tumour recurrence. CONCLUSIONS: It can improve the safety and feasibility of LRLR for rHCC, according to the degree of adhesion of the peritoneal adhesions and the first hepatic portal, then selecting the appropriate technique to control the bleeding of the hepatectomy.

Polymer-free patterning of graphene at sub-10-nm scale by low-energy repetitive electron beam.

A polymer-free technique for generating nanopatterns on both synthesized and exfoliated graphene sheets is proposed and demonstrated. A low-energy (5-30 keV) scanning electron beam with variable repetition rates is used to etch suspended and unsuspended graphene sheets on designed locations. The patterning mechanisms involve a defect-induced knockout process in the initial etching stage and a heat-induced curling process in a later stage. Rough pattern edges appear due to inevitable stochastic knockout of carbon atoms or graphene structure imperfection and can be smoothed by thermal annealing. By using this technique, the minimum feature sizes achieved are about 5 nm for suspended and 7 nm for unsuspended graphene. This study demonstrates a polymer-free direct nanopatterning approach for graphene.

Robotic gastrectomy versus laparoscopic gastrectomy for gastric cancer: comparison of surgical performance and short-term outcomes.

PURPOSE: This study was designed to compare robot-assisted gastrectomy with laparoscopy-assisted gastrectomy in surgical performance and short-term clinical outcomes for gastric cancer and evaluate the safety and feasibility of robotic surgery. METHODS: A retrospective database of patients who underwent robotic or laparoscopic gastrectomy for gastric cancer between March 2010 and May 2013 was examined. After screening, 514 patients who underwent gastrectomy for gastric cancer were enrolled in this study: 120 robotic and 394 laparoscopic surgery. Patient demographics, surgical performance, and short-term clinical outcomes were examined. RESULTS: All operations were performed successfully. The clinicopathologic characteristics were similar between the two groups. Compared with the laparoscopic group, the robotic group had less intraoperative blood loss (118.3 ± 55.8 vs. 137.6 ± 61.6 ml, P < 0.001), more lymph nodes dissection (34.6 ± 10.9 vs. 32.7 ± 11.2, P = 0.013), and longer operation time (234.8 ± 42.4 vs. 221.3 ± 44.8 min, P = 0.003). The survival rates were 90.2% at 1 year, 78.1% at 2 years, and 67.8% at 3 years in the RAG group compared with 87.3% at 1 year, 77.1% at 2 years, and 69.9% at 3 years in the LAG group. The difference in overall survival rate between the two groups was not statistically significant (P = 0.812). In view of lymph node involvement, the 3-year survival rates for patients with negative nodal metastasis were 84.4% in the RAG group versus 82.6% in the LAG group (P = 0.972) and 57.5% in the RAG group versus 60.3% in the LADG group (P = 0.653) for those with positive nodal metastasis. CONCLUSIONS: Comparing well with laparoscopic gastrectomy, robot-assisted gastrectomy is a feasible and safe surgical procedure with clear operation field, precise dissection, minimal trauma, and fast recovery. Longer follow-up time and randomized, clinical trials are needed to evaluate the clinical benefits and long-term oncological outcomes of this new technology.

Risk Factors for Anorectal Dysfunction After Interspincteric Resection in Patients With Low Rectal Cancer.

Purpose: The objective of this study was to explore the risk factors for anorectal dysfunction after intersphincteric resection in patients with low rectal cancer. Methods: A total of 251 patients who underwent intersphincteric resection from July 2014 to June 2020 were included in this study, for which the Kirwan's grade, Wexner score, and anorectal manometric index were used to evaluate the anorectal function and other parameters including demographics, surgical features, and clinical and pathological characteristics. These parameters were analysed to explore the potential risk factors for anorectal function after intersphincteric resection. Results: In the 251 included patients, 98 patients underwent partial intersphincteric resection, 87 patients underwent subtotal intersphincteric resection, and 66 patients underwent total intersphincteric resection. There were 53 (21.1%) patients who had postoperative complications, while no significant difference was observed between the three groups. Furthermore, 30 patients (45.5%) in the total intersphincteric resection group were classified as having anorectal dysfunction (Kirwan's grade 3-5), which was significantly higher than that in the partial intersphincteric resection group (27.6%) and subtotal intersphincteric resection group (29.9%). The mean Wexner score of patients that underwent total intersphincteric resection was 7.9, which was higher than that of patients that had partial intersphincteric resection (5.9, p = 0.002) and subtotal intersphincteric resection (6.4, p = 0.027). The initial perceived volume was lower in the total intersphincteric resection group than in the partial and subtotal intersphincteric resection groups at 1, 3, and 6 months after intersphincteric resection. In addition, the resting pressure, maximum squeeze pressure, and maximum tolerated volume in the total intersphincteric resection group were worse than those in the partial and subtotal groups at 3 and 6 months after intersphincteric resection. Univariate and multivariate analyses suggested that an age ≥65, total intersphincteric resection, and preoperative chemoradiotherapy were independent risk factors for anorectal dysfunction (P = 0.023, P = 0.003, and P = 0.008, respectively). Among the 66 patients who underwent total intersphincteric resection, 17 patients received preoperative chemoradiotherapy, of which 12 patients (70.6%) were classified as having anorectal dysfunction. Conclusion: The current study concluded that age ≥65, total intersphincteric resection, and preoperative chemoradiotherapy were risk factors for anorectal dysfunction after intersphincteric resection. The morbidity of anorectal dysfunction after total intersphincteric resection for patients who received preoperative chemoradiotherapy was relatively high, and the indication should be carefully evaluated.

Postoperative Functional Management Contributes to Anal Functional Recovery in Patients With Low Rectal Cancer After Robotic Total Intersphincteric Resection.

Purpose: To evaluate the effectiveness of the comprehensive post-operative management including low-frequency endo-anal electrical stimulation and daily suppository usage on post-operative anal functional recovery for low rectal cancer patients who underwent robotic total intersphincteric resection (ISR). Methods: A retrospective analysis was performed on 42 low rectal cancer patients who underwent robotic total ISR, of which 23 patients received comprehensive post-operative management, including biofeedback low-frequency endo-anal electrical stimulation and daily suppository usage (management group). Wexner score and anorectal manometric values, including resting pressure (RP), maximum squeeze pressure (MSP), initial perceived volume (IPV), and maximum tolerated volume (MTV), were assessed and compared. Results: A total of 42 low rectal cancer patients were included in our study. The RP at 6 months after ISR (40.95 ± 6.95 mmHg vs. 33.29 ± 5.40 mmHg, p = 0.002) and MSP at 3 and 6 months after ISR (72.05 ± 10.16 mmHg vs. 69.05 ± 8.67 mmHg, p = 0.031; 91.57 ± 15.47 mmHg vs. 84.05 ± 12.94 mmHg, p = 0.039, respectively) were significantly higher in the management group. The median IPV at 1 and 3 months after ISR (17.81 ± 3.61 ml vs. 15.43 ± 5.08 ml, p = 0.038; 20.19 ± 4.35 ml vs. 17.67 ± 5.16 ml, p = 0.044, respectively) and MTV at 3 months after ISR (83.71 ± 5.44 ml vs. 76.10 ± 8.42 ml, p = 0.012) were significantly higher in the management group. Wexner scores at 1 and 3 months after closure of stoma (COS) in the management group were significantly lower (11.3 ± 2.9 vs. 13.4 ± 3.0, p = 0.041; 8.9 ± 2.0 vs. 10.6 ± 2.4, p = 0.036, respectively). Conclusions: Comprehensive post-operative management could accelerate the recovery of sphincteric function and anal sensitivity after robotic total ISR and could also contribute to treatment of fecal incontinence followed by COS.

Robotic versus laparoscopic rectal resection surgery: Short-term outcomes and complications: A retrospective comparative study.

BACKGROUND: The safety of robotic-assisted surgery (RAS) remains a concern. This study aimed to compare the complications after RAS versus laparoscopic-assisted surgery (LAS) for rectal cancer using the Clavien-Dindo classification and to identify risk factors related to the complications. METHOD: Between March 2010 and June 2016, 556 rectal cancer patients who underwent successful RAS and 1029 patients who received LAS were enrolled in this study. The complications were graded according to the Clavien-Dindo classification, and the possible risk factors related to the complications were analyzed. RESULTS: The overall postoperative complication rate was 14.9%, with a 5% rate of severe complications that were classified as grade III or above in RAS group compared with 17.1% and 4.4% in LAS group. However, no significant difference was found (P = 0.608). A high ASA score was identified as an independent risk factor for overall and severe complications in both groups. The use of more than 3 staples in each operation and the anastomotic site of the anal verge at less than 5 cm were independent risk factors for complications. CONCLUSIONS: RAS for rectal cancer is technically safe and it does not significantly improve the complication rate. The incidence of overall complications is still related to tumor location, the general condition of the patients, and the surgical approach.

RGO and Three-Dimensional Graphene Networks Co-modified TIMs with High Performances.

With the development of microelectronic devices, the insufficient heat dissipation ability becomes one of the major bottlenecks for further miniaturization. Although graphene-assisted epoxy resin (ER) display promising potential to enhance the thermal performances, some limitations of the reduced graphene oxide (RGO) nanosheets and three-dimensional graphene networks (3DGNs) hinder the further improvement of the resulting thermal interface materials (TIMs). In this study, both the RGO nanosheets and 3DGNs are adopted as co-modifiers to improve the thermal conductivity of the ER. The 3DGNs provide a fast transport network for phonon, while the presence of RGO nanosheets enhances the heat transport at the interface between the graphene basal plane and the ER. The synergy of these two modifiers is achieved by selecting a proper proportion and an optimized reduction degree of the RGO nanosheets. Moreover, both the high stability of the thermal conductivity and well mechanical properties of the resulting TIM indicate the potential application prospect in the practical field.

Study on the supramolecular multirecognition mechanism of beta-naphthol/beta-cyclodextrin/anionic surfactant in a tolnaftate hydrolysis system.

Based on the fact that tolnaftate degrade to beta-naphthol sodium (RONa) at 5.00 mol/L NaOH solution and RO(-) was protonated to ROH after being acidified and adjusted to the pH 4.50 by acetic acid-sodium acetate buffer solution, we studied and discussed the mechanism of the supramolecular multirecognition interaction among the anionic surfactants sodium lauryl sulfate (SLS), beta-cyclodextrin (beta-CD), and beta-naphthol (ROH) by means of fluorescence spectrum, surface tension of the solution, infrared spectrograms, and (1)HNMR spectroscopy. The apparent formation constant of the ternary inclusion complex was determined to be (5.48 +/- 0.13) x 10(3) L(2)/mol(2). The thermodynamic parameters (DeltaG degrees, DeltaH degrees, DeltaS degrees ) for the formation of the inclusion complexes were obtained from the van't Hoff equation. It was indicated that the multiple and synergistic protection effect of SLS and beta-CD on the excited singlet state ROH played very important roles in the enhancement of the fluorescence of ROH. Results showed that, at room temperature, the naphthalene ring of ROH and the hydrophobic hydrocarbon chain of SLS were included into the cavity of beta-CD to form a ROH/SLS/beta-CD ternary inclusion complex with stoichiometry of 1:1:1, which provided effective protection for the excited state of ROH and increased the fluorescent intensity of ROH obviously.

[Positive circulating tumor cells in the peripheral blood may indicate a poor prognosis in patients with hepatocellular carcinoma].

OBJECTIVE: To assess the value of detecting peripheral blood circulating tumor cells (CTCs) in the diagnosis and treatment of hepatocellular carcinoma (HCC). METHODS: A total of 296 patients diagnosed with HCC admitted in our department from July 2013 to January 2015 were analyzed, with 39 patients with benign liver disease serving as the control group. The distribution of CTCs in the peripheral blood of HCC patients were detected by CanPatrol(TM) CTCs, and its relationship with the clinical features and prognosis of the patients were analyzed. RESULTS: s CTCs were detected in 64.5% (191/296) of the HCC patients but in none of the control group (P<0.05). Positive CTCs in peripheral blood of HCC patients were significantly correlated with serum AFP level, tumor number, TNM stage, BCLC stage, portal vein tumor thrombus and metastasis (P<0.05). In 127 HCC patients receiving radical surgery, the patients positive for CTCs showed significantly shorter relapse-free survival time (P<0.05). CONCLUSION: Positive CTCs in the peripheral blood may indicate a poor prognosis in HCC patients. CTCs may serve as a indicator for monitoring the prognosis of HCC.

Gait recognition and walking exercise intensity estimation.

Cardiovascular patients consult doctors for advice regarding regular exercise, whereas obese patients must self-manage their weight. Because a system for permanently monitoring and tracking patients' exercise intensities and workouts is necessary, a system for recognizing gait and estimating walking exercise intensity was proposed. For gait recognition analysis, αß filters were used to improve the recognition of athletic attitude. Furthermore, empirical mode decomposition (EMD) was used to filter the noise of patients' attitude to acquire the Fourier transform energy spectrum. Linear discriminant analysis was then applied to this energy spectrum for training and recognition. When the gait or motion was recognized, the walking exercise intensity was estimated. In addition, this study addressed the correlation between inertia and exercise intensity by using the residual function of the EMD and quadratic approximation to filter the effect of the baseline drift integral of the acceleration sensor. The increase in the determination coefficient of the regression equation from 0.55 to 0.81 proved that the accuracy of the method for estimating walking exercise intensity proposed by Kurihara was improved in this study.

Variable selection for discriminating herbal medicines with chromatographic fingerprints.

When discriminating herbal medicines with pattern recognition based on chromatographic fingerprints, typically, the majority of variables/data points contain no discrimination information. In this paper, chemometric approaches concerning forward selection and key set factor analysis using principal component analysis (PCA), unweighted and weighted methods based on the inner- and outer-variances, Fisher coefficient from the between- and within-class variations were investigated to extract representative variables. The number of variables retained was determined based on the cumulative variance percent of principal components, the ratio of observations to variables and the factor indicative function (IND). In order to assess the methods for variable selection and criteria levels to determine the number of variables retained, the original and reduced datasets were compared with Procrustes analysis and a weighted measure of similarity. Moreover, the tri-variate plots of the first three PCA scores were used to visually examine the reduced datasets in low dimensional space. Herbal samples were finally discriminated by use of Bayes discrimination analysis with the reduced subsets. The case study for 79 herbal samples showed that, the methods of forward selection associating the variables with the loadings closest to 0 and key set factor analysis were preferable to determine the representative variables. Procrustes analysis and the weighted measure were not indicative to extract representative variables. High matching between the original and reduced datasets did not suggest high prediction accuracy. Visually examining the PC1-PC2-PC3 scores projection plots with the reduced subsets, not all the herb samples could be separated due to the complexity of chromatographic fingerprints.