Virus shedding dynamics in asymptomatic and mildly symptomatic patients infected with SARS-CoV-2.

OBJECTIVES: Asymptomatic patients, together with those with mild symptoms of coronavirus disease 2019 (COVID-19), may play an important role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. However, the dynamics of virus shedding during the various phases of the clinical course of COVID-19 remains unclear at this stage. METHODS: A total of 18 patients found to be positive for SARS-CoV-2 infection by real-time reverse transcription PCR (RT-PCR) assay and admitted to Chongqing University Central Hospital between 29 January and 5 February 2020 were enrolled into this study. Medical data, pulmonary computed tomographic (CT) scan images and RT-PCR results were periodically collected during the patients' hospital stay. All participants were actively followed up for 2 weeks after discharge. RESULTS: A total of nine (50%) asymptomatic patients and nine (50%) patients with mild symptoms of COVID-19 were identified at admission. Six patients (66.7%) who were asymptomatic at admission developed subjective symptoms during hospitalization and were recategorized as being presymptomatic. The median duration of virus shedding was 11.5, 28 and 31 days for presymptomatic, asymptomatic and mildly symptomatic patients, separately. Seven patients (38.9%) continued to shed virus after hospital discharge. During the convalescent phase, detectable antibodies to SARS-CoV-2 and RNA were simultaneously observed in five patients (27.8%). CONCLUSIONS: Long-term virus shedding was documented in patients with mild symptoms and in asymptomatic patients. Specific antibody production to SARS-CoV-2 may not guarantee virus clearance after discharge. These observations should be considered when making decisions regarding clinical and public health, and when considering strategies for the prevention and control of SARS-CoV-2 infection.

[Surgical key points of precision functional sphincter-preserving surgery].

The principle of sphincter-preserving surgery is to preserve the anal sphincter function under the premise of radical resection. Due to low position of rectal tumor, conventional laparoscopic surgery has difficulties in operating in the deep and narrow pelvis, which may lead to inaccurate tissue dissociation, imprecise positioning of tumor edge, excessive stretch of the anal sphincter complex, and excessive removal of distal rectal mucosa. Moreover, pain from abdominal auxiliary incision has an unavoidable side effect for postoperative recovery. With the help of the Liu's transanal microsurgery system, precision functional sphincter-preserving surgery (PPS) can be successfully performed. PPS tries to preserve left colonic artery and pelvic autonomic nerve in the transabdominal operation. In the part of transanal surgery, measurement, localization and resection of the lower edge of the tumor are conducted under a clear and open visual field with the transparent screw anal dilator. After the rectum is cut off, the specimen is taken out through the anus to avoid abdominal incision. Inserting the intestinal supporter to support the bowel stump, full thickness of bowel stump is then sutured with anal canal by vertical mattress suture. Special transanal tube is placed afterwards without routine prophylactic stoma. PPS can achieve precise tumor resection and sphincter preservation simultaneously.

Sarcopenia in overweight and obese patients is a predictive factor for postoperative complication in gastric cancer: A prospective study.

BACKGROUND: Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength. This study aims to explore the prevalence of sarcopenia in overweight and obese gastric cancer (GC) patients and figured out the impacts of sarcopenia on the postoperative complication of overweight and obese GC patients. METHODS: According to the recommended body-mass index (BMI) for Asian populations by WHO, we conducted a prospective study of overweight and obese gastric cancer patients (BMI ≥ 23 kg/m2) under curative gastrectomy from August 2014 to December 2015. Including lumbar skeletal muscle index, handgrip strength and gait speed as the sarcopenic components were measured before surgery. Patients were followed up after gastrectomy to gain the actual clinical outcomes. Factors contributing to postoperative complications were analyzed by univariate and multivariate analysis. RESULTS: Total of 206 overweight or obese patients were enrolled in this study, 14 patients were diagnosed sarcopenia and were demonstrated having significantly association with higher risk of postoperative complications, higher hospital costs, and higher rate of 30-days readmission compared with the non-sarcopenic ones. On the basis of univariate and multivariate analysis, sarcopenia was an independent risk factor for postoperative complication of overweight and obese patients with gastric cancer (P = 0.002). CONCLUSION: Sarcopenia is an independent predictor of postoperative complications in overweight or obese patients with gastric cancer after radical gastrectomy.

Feasibility of radical gastrectomy for elderly patients with gastric cancer.

BACKGROUND: The aim of this study was to evaluate the short-term safety and long-term benefits of radical gastrectomy for gastric cancer in elderly patients. METHODS: A total of 729 patients undergoing gastrectomy for adenocarcinoma between December 2008 and December 2011 were enrolled in this retrospective study. Patients were divided into three groups: young group (<65 years), young-old group (65-79 years) and old-old group (≥80 years). RESULTS: Lower albumin levels, higher ASA grades, comorbidities, tumors located in the upper third of the stomach and advanced TNM stages were more common in the young-old and old-old age groups. Overall complications increased significantly with advancing age (15.4%, 24.9%, 48.7%, respectively); respiratory complications largely contributed to the dramatic increase. Severe complications were similar between the young and young-old groups (3.9%, 3.7%), but were significantly increased in the old-old group (12.8%). In multivariate analysis, old-old age, multiple comorbidities and no epidural use were strong predictors for overall complications. Both overall survival and disease-specific survival (DSS) rates declined with advancing age. Multivariate analysis showed that old-old age and TNM stage ≥ II were major independent risk factors for the DSS rate. When adjusted for confounding factors, young-old age was not a risk factor. The median survival time for the old-old patients with stage III tumors was 12.9 months. CONCLUSIONS: It is relatively safe and beneficial for young-old patients to undergo radical gastrectomy as the young patients. However, the decision to perform radical gastrectomy for old-old patients with TNM stage III tumors should be made carefully.

Sarcopenia, as defined by low muscle mass, strength and physical performance, predicts complications after surgery for colorectal cancer.

AIM: Recent studies have shown that sarcopenia is associated with negative postoperative outcomes. However, none of these studies analysed muscle strength or physical performance, which are also important components of sarcopenia. The present study aimed to investigate whether sarcopenia itself, as defined by low muscle mass, strength and physical performance, would predict complications after surgery for colorectal cancer. METHOD: We conducted a prospective study of patients who underwent surgery for colorectal cancer at our department between August 2014 and February 2015. Sarcopenia was diagnosed by a combination of third lumbar vertebra muscle index (L3 MI), handgrip strength and 6-m usual gait speed. Univariate and multivariate analyses evaluating the risk factors for postoperative complications were performed. Only complications classified as Grade II or above according to the Clavien-Dindo classification were analysed in this study. RESULTS: A total of 142 patients were included in the study, and 17 patients were diagnosed as having sarcopenia. Postoperative complications of Grade II or above occurred in 40 patients, including 10 with sarcopenia and 30 without sarcopenia. Multivariate analysis showed that sarcopenia and previous abdominal surgery were independent risk factors for postoperative complications. Patients with sarcopenia also had an obvious tendency to a higher incidence of infectious complications. By comparing two logistic regression models, sarcopenia showed a better predictive power for postoperative complications than did low muscle mass. CONCLUSION: Sarcopenia and previous abdominal surgery are independent risk factors for complications after surgery for colorectal cancer. Including a functional aspect to the definition of sarcopenia may result in a better prediction of postoperative complications.