重庆市孕前生殖健康与出生结局队列：设计简介与建设概况

出生队列是研究生命早期暴露对健康结局影响的重要工具, 但目前缺乏有力支撑孕前暴露特别是父系暴露对生殖健康和妊娠结局影响研究的大型队列平台。重庆市孕前生殖健康与出生结局队列研究是起始于孕前阶段, 同等关注男女双方的环境、心理、行为等暴露因素对生殖健康和不良妊娠结局影响的前瞻性队列研究。项目于2019年正式启动, 计划招募有生育意愿的育龄夫妇20 800人。通过随访, 调查志愿者2年内是否自然受孕。对进入妊娠期的女性志愿者, 在孕早、中、晚期进一步随访, 并对分娩的子代随访至2岁, 监测早产、低出生体重、出生缺陷、神经功能发育障碍等结局发生情况。各阶段分别采集相应的数据信息和生物样本, 包括精液、外周血、尿液、胎盘、脐带、脐带血、口腔拭子等。截至2022年1月, 已纳入志愿者8 698人, 分布于重庆市所有38个区/县。本队列建设目标是成为涵盖父母双方的前瞻性大样本孕前出生队列, 将以独特的设计和更加全面的视角阐明全生育周期特别是孕前期暴露因素对生殖健康和不良出生结局的影响及机制。     

基于三维重建的腹腔镜下胃癌根治术临床效果

目的探讨三维重建模型在腹腔镜下胃癌根治术(LAG)中的临床效果。方法采用随机数字表法将2018年6月至2019年12月间行LAG的84例胃癌患者分为三维组(n=42)和CT组(n=42)。CT组使用CT图像进行术前规划和术中应用,三维组依据CT数据采用Mimics 17.0软件进行患者三维腹腔血管重建,利用三维模型进行术前规划和术中应用。采用SPSS18.0软件进行统计学分析。围术期相关指标等计量资料以(±s)表示,采用独立t检验;术后并发症等计数资料采用χ²检验分析;以P<0.05表示差异有统计学意义。结果与CT组相比,三维组可明显缩短腹腔镜下胃癌根治术的手术时间、平均住院时间,减少术中出血量及术中输血,增加术中清除淋巴结个数,差异均具统计学意义(P<0.05)。而两组术后首次排气时间、术后并发症发生率差异均无统计学意义(P>0.05)。结论三维腹腔血管重建技术应用于LAG术中准确评估患者腹腔血管的分型及变异情况,在术中提供重要决策作用,具有明显优势,值得临床推广。     

保留幽门胃切除术后胃排空功能障碍的原因及防治

保留幽门胃切除术(PPG)治疗早期胃癌(EGC)通过减少胃切除的范围、保留幽门、保留迷走神经能够显著改善患者术后生活质量,降低术后倾倒综合征、胆汁返流及胆石症的发生率。腹腔镜辅助保留幽门胃切除术(LAPPG)将微创理念及功能保留结合,具有低侵袭性,最低限度的小肠麻痹,术后早期康复等优势。然而,无论PPG或LAPPG,术后早期胃排空功能障碍(GEF)的发生率较高,表现为食物长期存留于残胃之中,病人通常有饱腹感。本文综述近几年行PPG术后胃排空功能障碍的相关研究进展,为临床一线外科医生行PPG或LAPPG治疗EGC时防治GEF提供参考建议。     

Enforcing Imprecise Constraints on Generative Adversarial Networks for Emulating Physical Systems

Generative adversarial networks (GANs) were initially proposed to generate images by learning from a large number of samples. Recently, GANs have been used to emulate complex physical systems such as turbulent flows. However, a critical question must be answered before GANs can be considered trusted emulators for physical systems: do GANs-generated samples conform to the various physical constraints? These include both deterministic constraints (e.g., conservation laws) and statistical constraints (e.g., energy spectrum of turbulent flows). The latter have been studied in a companion paper (Wu et al., Enforcing statistical constraints in generative adversarial networks for modeling chaotic dynamical systems. Journal of Computational Physics. 406, 109209, 2020). In the present work, we enforce deterministic yet imprecise constraints on GANs by incorporating them into the loss function of the generator. We evaluate the performance of physics-constrained GANs on two representative tasks with geometrical constraints (generating points on circles) and differential constraints (generating divergence-free flow velocity fields), respectively. In both cases, the constrained GANs produced samples that conform to the underlying constraints rather accurately, even though the constraints are only enforced up to a specified interval. More importantly, the imposed constraints significantly accelerate the convergence and improve the robustness in the training, indicating that they serve as a physics-based regularization. These improvements are noteworthy, as the convergence and robustness are two well-known obstacles in the training of GANs.     

Mid‐ to Long‐Term Outcomes of Cementless Modular,Fluted, Tapered Stem for Massive Femoral Bone Loss in Revision Total Hip Arthroplasty

ObjectiveTo evaluate mid‐ to long‐term results of revision total hip arthroplasty for massive femoral bone loss using a cementless modular, fluted, tapered stem.MethodsThis is a retrospective study performed at a single hospital. During the period of January 2007 to January 2015, 33 patients (34 hips) underwent primary revision surgery with cementless modular, fluted, tapered stems due to femoral bone loss. Sixteen men and 17 women were included in the study, with an average age of 63.9 ± 11.7 years (range, 27 to 88 years). Operative data including operative duration, length of incision, drainage volume and duration, blood loss and transfusion, cases of bone graft and extended trochanteric osteotomy were recorded. Clinical evaluation was performed using Harris hip score (HHS), visual analogue scale (VAS), and patients'' satisfaction. Radiographic data including femoral stem fixation, subsidence, integrin of allograft bone, and leg length discrepancy were assessed. Complications and survivorship were evaluated using Kaplan–Meier survival rate.ResultsThe mean follow‐up was 9.1 ± 2.5 years (range, 5–13 years). The Harris hip score was 43.6 ± 11.5 preoperatively and maintained at 86.5 ± 6.6 at the time of latest follow‐up (P < 0. 05). The X‐ray showed bone ingrowth fixation in 30 hips (88%), fibrous stable fixation in three hips (9%), and instability in one hip (3%). The average stem subsidence was 3.9 ± 2.2 mm (range, 1 to 10 mm). The mean difference in leg length in our study was 3.3 ± 2.7 mm (range, 0 to 10 mm), and the leg length discrepancy in 28 (82%) patients was within 5 mm. No case of junction fracture was observed. Seven (21%) intraoperative fractures occurred in our study. Three (9%) cases with infection were observed after revision. Six (18%) patients had lower limb vein thrombosis. The survivorship of prostheses with re‐revision for any reason was 95% (95% CI, 12.0 to 13.0) at the 10‐year follow‐up. Three (9%) re‐revisions were needed, including one for aseptic loosening, one for dislocation, and one for infection.ConclusionThe mid‐ to long‐term results of revision total hip arthroplasty with the cementless modular, fluted, tapered stems are encouraging for massive femoral bone loss.     

Risk Factors and Outcomes for Preoperative Asymptomatic Pulmonary Embolism in Patients Aged 60 Years and Over with Hip Fracture

ObjectiveTo investigate the risk factors for, and outcomes of, preoperative asymptomatic pulmonary embolism (PE) in patients ≥60 years old following delayed operation for hip fracture.MethodsFrom March 2017 to December 2018, 90 patients aged ≥60 years with hip fracture who suffered a delay in surgery were recruited to this prospective study following admission to our hospital. Computed tomography pulmonary angiography (CTPA) was used to detect preoperative asymptomatic PE and calculated its incidence. Time from injury to admission, baseline characteristics, medical comorbidities, and blood biomarker levels were evaluated as potential risk factors. Logistic regression analysis was used to identify risk factors. Mortality and major bleeding events were recorded and compared between individuals with PE and without. Data were analyzed by t‐test, Mann–Whitney U test, χ ² test, Fisher''s exact test, and logistic regression analysis.ResultsThe incidence of preoperative asymptomatic PE was 18.9% (17/90 patients). In the univariate analysis, the risk factors for preoperative asymptomatic PE were male sex, hypertension, cerebrovascular accident, smoking, plasma D‐dimer level, potassium level, urea level, creatinine level, and cysteine level. Multivariate logistic regression analysis showed that the risk of preoperative asymptomatic PE was higher in patients with hypertension (odds ratio [OR] = 10.048; 95% confidence interval [CI], 1.118–90.333), cerebrovascular accident (OR = 20.135; 95% CI, 1.875–216.164), smoking (OR = 48.741; 95% CI, 4.155–571.788), high plasma D‐dimer levels (OR = 1.200; 95% CI, 1.062–157.300), and high plasma potassium levels (OR = 12.928; 95% CI, 1.062–157.300). All patients were followed up for 21.0 months (range, 2 to 36 months). Mortality within the first year postoperatively was higher in patients with PE (29.41% vs 9.59%, P = 0.046).ConclusionsIn view of the high incidence of preoperative asymptomatic PE and the inferior prognosis in individuals with PE, routine CTPA examination for preoperative asymptomatic PE could be useful for patients aged ≥60 years with hip fracture for whom surgery is delayed.     

Predictive model containing PI-RADS v2 score for postoperative seminal vesicle invasion among prostate cancer patients

BackgroundSeminal vesicle invasion (SVI) is considered to be one of most adverse prognostic findings in prostate cancer, affecting the biochemical progression-free survival and disease-specific survival. Multiparametric magnetic resonance imaging (mpMRI) has shown excellent specificity in diagnosis of SVI, but with poor sensitivity. The aim of this study is to create a model that includes the Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) score to predict postoperative SVI in patients without SVI on preoperative mpMRI.MethodsA total of 262 prostate cancer patients without SVI on preoperative mpMRI who underwent radical prostatectomy (RP) at our institution from January 2012 to July 2019 were enrolled retrospectively. The prostate-specific antigen levels in all patients were <10 ng/mL. Univariate and multivariate logistic regression analyses were used to assess factors associated with SVI, including the PI-RADS v2 score. A regression coefficient-based model was built for predicting SVI. The receiver operating characteristic curve was used to assess the performance of the model.ResultsSVI was reported on the RP specimens in 30 patients (11.5%). The univariate and multivariate analyses revealed that biopsy Gleason grade group (GGG) and the PI-RADS v2 score were significant independent predictors of SVI (all P<0.05). The area under the curve of the model was 0.746 (P<0.001). The PI-RADS v2 score <4 and Gleason grade <8 yielded only a 1.8% incidence of SVI with a high negative predictive value of 98.2% (95% CI, 93.0–99.6%).ConclusionsThe PI-RADS v2 score <4 in prostate cancer patients with prostate-specific antigen level <10 ng/mL is associated with a very low risk of SVI. A model based on biopsy Gleason grade and PI-RADS v2 score may help to predict SVI and serve as a tool for the urologists to make surgical plans.