[Mechanisms and clinical management of small bowel obstruction caused by kinking of the jejunojejunal anastomosis after laparoscopic Roux-en-Y gastric bypass]

Currently, obesity and its complications have become increasingly serious health issues. Bariatric surgery is an effective method of treating obesity and related metabolic complications. Among them, Roux-en-Y gastric bypass (RYGB) is still considered the "gold standard" procedure for bariatric surgery. Small bowel obstruction is one of the possible complications after RYGB, and in addition to the formation of intra-abdominal hernias, kinking of the jejunojejunal anastomosis is an important cause of small bowel obstruction. The early clinical symptoms of kinking of the jejunojejunal anastomosis often lack clarity in the early stages. Therefore, early diagnosis, prevention, and effective treatment of kinking of the jejunojejunal anastomosis are challenging but crucial. The occurrence of kinking of the jejunojejunal anastomosis may be related to surgical techniques and the surgeon's experience. The use of anti-obstruction stitch, mesenteric division, and bidirectional jejunojejunal anastomosis may be beneficial in preventing kinking of the jejunojejunal anastomosis. If kinking of the jejunojejunal anastomosis occurs, timely abdominal CT scans and endoscopic examinations should be performed. Gastric and intestinal decompression should be initiated immediately, and exploratory surgery should be prepared.

[Construction of a model based on multipoint full-layer puncture biopsy for predicting pathological complete response after neoadjuvant therapy for locally advanced rectal cancer]

Objective: To investigate the value of transanal multipoint full-layer puncture biopsy (TMFP) in predicting pathological complete response (pCR) after neoadjuvant radiotherapy and chemotherapy (nCRT) in patients with locally advanced rectal cancer (LARC) and to establish a predictive model for providing clinical guidance regarding the treatment of LARC. Methods: In this multicenter, prospective, cohort study, we collected data on 110 LARC patients from four hospitals between April 2020 and March 2023: Beijing Chaoyang Hospital of Capital Medical University (50 patients), Beijing Friendship Hospital of Capital Medical University (41 patients), Qilu Hospital of Shandong University (16 patients), and Zhongnan Hospital of Wuhan University (three patients). The patients had all received TMFP after completing standard nCRT. The variables studied included (1) clinicopathological characteristics; (2) clinical complete remission (cCR) and efficacy of TMFP in determining pCR after NCRT in LARC patients; and (3) hospital attended, sex, age, clinical T- and N-stages, distance between the lower margin of the tumor and the anal verge, baseline and post-radiotherapy serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 concentrations, chemotherapy regimen, use of immunosuppressants with or without radiotherapy, radiation therapy dosage, interval between surgery and radiotherapy, surgical procedure, clinical T/N stage after radiotherapy, cCR, pathological results of TMFP, puncture method (endoscopic or percutaneous), and number and timing of punctures. Single-factor and multifactorial logistic regression analysis were used to determine the factors affecting pCR after NCRT in LARC patients. A prediction model was constructed based on the results of multivariat analysis and the performance of this model evaluated by analyzing subject work characteristics (ROC), calibration, and clinical decision-making (DCA) curves. pCR was defined as complete absence of tumor cells on microscopic examination of the surgical specimens of rectal cancer (including lymph node dissection) after NCRT, that is, ypT0+N0. cCR was defined according to the Chinese Neoadjuvant Rectal Cancer Waiting Watch Database Study Collaborative Group criteria after treatment, which specify an absence of ulceration and nodules on endoscopy; negative rectal palpation; no tumor signals on rectal MRI T2 and DWI sequences; normal serum CEA concentrations, and no evidence of recurrence on pelvic computed tomography/magnetic resonance imaging. Results: Of the 110 patients, 45 (40.9%) achieved pCR after nCRT, which was combined with immune checkpoint inhibitors in 34 (30.9%). cCR was diagnosed before puncture in 38 (34.5%) patients, 43 (39.1%) of the punctures being endoscopic. There were no complications of puncture such as enterocutaneous fistulae, vaginal injury, prostatic injury, or presacral bleeding . Only one (2.3%) patient had a small amount of blood in the stools, which was relieved by anal pressure. cCR had a sensitivity of 57.8% (26/45) for determining pCR, specificity of 81.5% (53/65), accuracy of 71.8% (79/110), positive predictive value 68.4% (26/38), and negative predictive value of 73.6% (53/72). In contrast, the sensitivity of TMFP pathology in determining pCR was 100% (45/45), specificity 66.2% (43/65), accuracy 80.0% (88/110), positive predictive value 67.2% (45/67), and negative predictive value 100.0% (43/43). In this study, the sensitivity of TMFP for pCR (100.0% vs. 57.8%, χ2=24.09, P<0.001) was significantly higher than that for cCR. However, the accuracy of pCR did not differ significantly (80.0% vs. 71.8%, χ2=2.01, P=0.156). Univariate and multivariate logistic regression analyses showed that a ≥4 cm distance between the lower edge of the tumor and the anal verge (OR=7.84, 95%CI: 1.48-41.45, P=0.015), non-cCR (OR=4.81, 95%CI: 1.39-16.69, P=0.013), and pathological diagnosis by TMFP (OR=114.29, the 95%CI: 11.07-1180.28, P<0.001) were risk factors for pCR after NCRT in LARC patients. Additionally, endoscopic puncture (OR=0.02, 95%CI: 0.05-0.77, P=0.020) was a protective factor for pCR after NCRT in LARC patients. The area under the ROC curve of the established prediction model was 0.934 (95%CI: 0.892-0.977), suggesting that the model has good discrimination. The calibration curve was relatively close to the ideal 45° reference line, indicating that the predicted values of the model were in good agreement with the actual values. A decision-making curve showed that the model had a good net clinical benefit. Conclusion: Our predictive model, which incorporates TMFP, has considerable accuracy in predicting pCR after nCRT in patients with locally advanced rectal cancer. This may provide a basis for more precisely selecting individualized therapy.

[Research progress of bariatric and metabolic surgery in the prevention of gastroesophageal reflux disease]

Gastroesophageal reflux disease (GERD) is a common digestive tract disease. Obesity is an independent risk factor for GERD. Laparoscopic sleeve gastrectomy (laparoscopic sleeve gastrectomy, LSG) is becoming more popular in bariatric metabolic surgery and is simple to perform with fewer complications, but its efficacy in treating postoperative anti-reflux in obese patients remains controversial. LSG has been reported to disrupt anti-reflux barrier function, such as altered cardiac notch, disruption of diaphragmatic continuity, and increased hiatal hernia after surgery. The cardiac notch is one of the important anti-reflux barriers at the gastroesophageal junction, and its accentuation has been shown to be effective in alleviating the symptoms of GERD, and LSG combined with angle of cardiac notch accentuation is expected to be an effective measure to prevent GERD after obesity surgery. Therefore, this article mainly reviews the research on the prevention of GERD by bariatric surgery, aiming to explore the effective treatment of GERD in obese patients after surgery, so as to improve the symptoms and quality of life of patients with GERD, and provide reference for the surgical treatment of GERD.

[Evaluation strategy of complete response after neoadjuvant therapy for rectal cancer]

Currently, the standard of clinical complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT) for local advanced rectal cancer generally lacks pathological examination, the cCR judged by the current standard is still far from the real pathological complete response. After nCRT, due to the presence of tissue edema and fibrosis, MRI is highly uncertain in determining the staging of local lesions. The precision of colonoscopy biopsy is generally low because residual cancer foci exist primarily in the muscular layer, which limits the determination of cCR by colonoscopy biopsy. Local excision through the anus can resect the whole intestinal wall tissue, which is relatively accurate and close to the real state of remission of the lesion, but there are many problems, such as affecting anal function, high rate of complications, and increased difficulty of following radical surgery. Based on the present diagnosis of cCR, the authors put forward the concept of modified cCR (m-cCR) which combined with the pathological standard of transanal multipoint full-layer puncture biopsy. It is possible to improve the accuracy of cCR, and improve the safety of cCR patients who receive wait-and-watch therapy without increasing complications or affecting anal function. The exact conclusion needs to be confirmed by further studies.

[The value of transanal multipoint full-layer puncture biopsy in determining the response degree of rectal cancer following neoadjuvant therapy: a prospective multicenter study]

Objective: To verify the feasibility and accuracy of the transanal multipoint full-layer puncture biopsy (TMFP) technique in determining the residual status of cancer foci after neoadjuvant therapy (nCRT) in rectal cancer. Methods: Between April 2020 and November 2022, a total of 78 patients from the Beijing Chaoyang Hospital of Capital Medical University, the Beijing Friendship Hospital of Capital Medical University, the Qilu Hospital of Shandong University, the Zhongnan Hospital of Wuhan University with advanced rectal cancer received TMFP after nCRT participated in this prospective multicenter trial. There were 53 males and 25 females, aged (M(IQR)) 61 (13) years (range: 35 to 77 years). The tumor distance from the anal verge was 5 (3) cm (range: 2 to 10 cm). The waiting time between nCRT and TMFP was 73 (26) days (range: 33 to 330 days). 13-point transanal puncture was performed with a 16 G tissue biopsy needle with the residual lesion as the center. The specimens were submitted for independent examination and the complications of the puncture were recorded. The consistency of TMFP and radical operation specimen was compared. The consistency of TMPF with clinical remission rates for the diagnosis of complete pathological remission was compared by sensitivity, specificity, negative predictive value, positive predictive value and accuracy. Statistical analysis between groups was performed using the χ2 analysis, and a paired χ2 test was used to compare diagnostic validity. Results: Before TMFP, clinical complete response (cCR) was evaluated in 27 cases. Thirty-six cases received in vivo puncture, the number of punctures in each patient was 13 (8) (range: 4 to 20), 24 cases of tumor residue were found in the puncture specimens. The sensitivity to judgment (100% vs. 60%, χ2=17.500, P<0.01) and accuracy (88.5% vs. 74.4%, χ2=5.125, P=0.024) of TMFP for the pathologic complete response (pCR) were significantly higher than those of cCR. Implement TMFP based on cCR judgment, the accuracy increased from 74.4% to 92.6% (χ2=4.026, P=0.045). The accuracy of the in vivo puncture was 94.4%, which was 83.3% of the in vitro puncture (χ2=1.382, P=0.240). Overall, the accuracy of TMFP improved gradually with an increasing number of cases (χ2=7.112, P=0.029). Conclusion: TMFP is safe and feasible, which improves the sensitivity and accuracy of rectal cancer pCR determination after nCRT, provides a pathological basis for cCR determination, and contributes to the safe development of the watch and wait policy.

[Meta-analysis comparing long-term outcomes of intersphincteric resection versus abdominoperineal resection for low rectal cancer]

Objective: To compare the long-term outcomes of intersphincteric (trans-internal and external) sphincter resection (ISR) and abdominoperineal proctocolectomy (APR) for low-grade rectal cancer. Methods: We used a meta-analytic approach to compare these procedures . Published reports comparing ISR and APR for low rectal cancer in Pubmed, Medline, EMBASE and Cochrane, China Knowledge Network (CNKI), China Biomedical Literature Database, and Vipers databases between January 2005 and January 2023 were searched and those meeting the eligibility criteria were selected for extraction of data for analysis. Inclusion criteria were as follows: (1) all reports comparing ISR and APR for low rectal cancer before January 2023; and (2) prospective randomized controlled studies or well-designed cohort studies. Exclusion criteria were as follows: (1) full text not available; (2) duplicate publications, missing primary outcome indicators, and unknown data; and (3) invalid statistical analysis. Results: Sixteen studies with 2498 patients were included in this study. Compared with the APR group, patients in the ISR group were relatively younger (weighted mean difference [WMD]=-1.82, 95%CI=-2.94 to -0.70, P=0.01), had tumors farther from the anal verge (WMD=0.43, 95%CI=0.18 to 0.67, P<0.01), and lower pathological T-stage (T3-4 stage: OR=0.54, 95%CI=0.36 to 0.81, P<0.01). In contrast, there were no statistically significant differences between the two groups in gender (P=0.78), body mass index (P=0.77), or pathological N stage (P=0.09). Compared with the APR group, patients in the ISR group had a lower rate of postoperative complications (OR=0.77, 95%CI=0.60 to 0.99, P=0.04), shorter hospital stay (WMD=-4.30, 95%CI=-7.07 to -1.53, P<0.01), higher 5-year overall survival (HR=0.54, 95%CI=0.33 to 0.88, P=0.01), and higher 5-year disease-free survival (HR=0.65, 95%CI=0.47 to 0.90, P<0.01). Five-year locoregional failure (HR=0.66, 95%CI=0.40 to 1.10, P=0.11) and time to surgery (WMD=-9.71, 95%CI=-41.89 to 22.47, P=0.55) did not differ significantly between the two groups. Conclusion: ISR is a safe and effective alternative to APR for early-stage low-grade rectal cancer.

[Treatment of obstructive colorectal cancer]

Obstructive colorectal cancer is a common malignant bowel obstruction. Colostomy or colostomy following tumor resection may be the first choice for emergency surgery. The intestinal and systemic conditions of patients undergoing emergency surgery are often poor, and patients need to undergo multiple operations, which increase the surgical risk and economic burden and reduce the quality of life of patients. Poor intraoperative visualization may also affect the radical operation of emergency surgery. Transanal decompression tube (TDT) can rapidly decompress and drain the obstructed bowel, effectively relieve obstruction symptoms, and improve the success rate of primary radical resection. The TDT squeeze the tumor lightly, causing no spread of tumor cells, and is cheap, but the cavity of transanal decompression tube is small and easily blocked, and requires tedious flushing or regular replacement. Self-expanding metallic stents (SEMS) can relieve intestinal obstruction effectively, provide sufficient preparation time for preoperative examination and improvement of nutritional status. By improving patient's tolerance to radical surgery, SEMS might be used as an important treatment strategy choice for obstructive colorectal cancer. However, SEMS may squeeze the tumor, leading to the spread of tumor cells, increase the recurrence rate and metastasis rate, and reduce the survival rate. Moreover, intestinal wall edema still existed during the operation following SEMS, and the rate of ostomy after anastomosis was as high as 34%. We hypothesized that prolonging the interval between stent insertion and surgery to 2 months, with neoadjuvant chemotherapy administered during this interval (SEMS-neoadjuvant chemotherapy strategy), would help improve outcomes. The SEMS-neoadjuvant chemotherapy strategy is a safe, effective, and well tolerated treatment approach with a high laparoscopic resection rate, low stoma formation rate and improvement in the overall survival for patients with left-sided colon cancer obstruction. The patient physical status is improved, the primary tumor is downstaged, and intestinal wall edema is relieved during the relatively longer interval between SEMS placement and surgery. The SEMS-neoadjuvant chemotherapy strategy may be a preferred therapeutic strategy for obstructive left colon cancer.

[Risk factors and prevent strategy of parastomal hernia]

Parastomal hernia is one of the common complications of stoma surgery with an incidence of more than 30%, which can be diagnosed by physical examination and abdominal CT. Risk factors of parastomal hernia might include stoma approaches including the selection of intestine, relationship between stoma and peritoneum, stoma location, aperture size, operation time and the patient's own conditions. It is essential to prevent parastomal hernia in order to improve patients' quality of life. Prophylactic mesh and perioperative care might prevent parastomal hernias. The mesh type might also influence the incidence of parastomal hernia. To reduce the incidence of recurrence of parastomal hernia, placement of mesh by the laparoscopic Sugarbaker technique was an effective surgical approach. How to prevent and repair parastomal hernia and cure parastomal hernia repair still needs further high-quality research to provide evidence.

[Effect of intestinal obstruction stent combined with neoadjuvant chemotherapy on the pathological characteristics of surgical specimens in patients with complete obstructive colorectal cancer]

Objective: To compare the effects of three treatment options: emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery, on the pathological characteris- tics of surgically-resected specimens from patients with completely obstructive colorectal cancer. Methods: This was a retrospective cohort study analyzing clinicopathological data of patients with complete obstructive colorectal cancer who were admitted to the General Surgery Department of Beijing Chaoyang Hospital, Capital Medical University, between May 2012 and August 2020. The inclusion criteria were diagnosed with complete colorectal obstruction, pathologically confirmed as adenocarcinoma, resectable on imaging assessment, and without distant metastasis, combined with the patients' clinical manifestations and imaging examination findings. Patients with multiple colorectal cancers, refusal to undergo surgery, and concurrent peritonitis or intestinal perforation before stenting of the intestinal obstruction were excluded. Eighty-nine patients with completely obstructive colorectal cancer were enrolled in the study and were divided into emergency surgery group (n=30), stent-surgery group (n=34), and stent-neoadjuvant chemotherapy- surgery group (n=25) according to the treatment strategy. Differences in the pathological features (namely perineural infiltration, lymphovascular infiltration, tumor deposits, specimen intravascular necrosis, inflammatory infiltration, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cell ratio) and biomolecular markers (namely cluster of differentiation (CD)34, Ki67, Bcl-2, matrix metalloproteinase-9, and hypoxia-inducible factor alpha) were recorded. Pathological evaluation was based on the presence or absence of qualitative evaluation of pathological features, such as peripheral nerve infiltration, vascular infiltration, and cancer nodules within the specimens. The evaluation criteria for the pathological features of the specimens were as follows: Semi-quantitative graded evaluation based on the proportion of tissue necrosis, inflammatory infiltrates, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cells in the field of view within the specimen were classified as: grade 0: not seen within the specimen; grade 1: 0-25%; grade 2: 25%-50%; grade 3: 50%-75%; and grade 4: 75%-100%. The intensity of cellular immunity was classified as none (0 points), weak (1 point), moderate (2 points), and strong (3 points). The two evaluation scores were then multiplied to obtain a total score of 0-12. The immunohistochemical results were also evaluated comprehensively, and the results were defined as: negative (grade 0): 0 points; weakly positive (grade 1): 1-3 points; moderately positive (grade 2): 4-6 points; strongly positive (grade 3): 7-9 points; and very strong positive (grade 4): 10-12 points. Normally-distributed values were expressed as mean±standard deviation, and one-way analysis of variance was used to analyze the differences between the groups. Non-normally-distributed values were expressed as median (interquartile range: Q1, Q3). A nonparametric test (Kruskal-Wallis H test) was used for comparisons between groups. Results: The differences were not statistically significant when comparing the baseline data for age, gender, tumor site, American Society of Anesthesiologists score, tumor T-stage, N-stage, and degree of differentiation among the three groups (all P>0.05). The differences were not statistically significant when comparing the pathological characteristics of the resected tumor specimens, such as foreign body giant cells, inflammatory infiltration, and mucus lake formation among the three groups (all P>0.05). The rates of vascular infiltration were 56.6% (17/30), 41.2% (15/34), and 20.0% (5/25) in the emergency surgery, stent-surgery, and stent- neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences between the groups (χ²=7.142, P=0.028). Additionally, the rate of vascular infiltration was significantly lower in the stent-neoadjuvant chemotherapy-surgery group than that in the emergency surgery group (P=0.038). Peripheral nerve infiltration rates were 55.3% (16/30), 41.2% (14/34), and 16.0% (4/25), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (χ²=7.735, P=0.021). The infiltration peripheral nerve rates in the stent-neoadjuvant chemotherapy-surgery group were significantly lower than those in the emergency surgery group (P=0.032). The necrosis grade was 2 (1, 2), 2 (1, 3), and 2 (2, 3) in the emergency surgery, stent- surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=10.090, P=0.006). Post hoc comparison revealed that the necrosis grade was higher in the stent-surgery and stent-neoadjuvant chemotherapy-surgery groups compared with the emergency surgery group (both P<0.05). The abscess grade was 2 (1, 2), 3 (1, 3), and 2 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=6.584, P=0.037). Post hoc comparison revealed that the abscess grade in the emergency surgery group was significantly lower than that in the stent-surgery group (P=0.037). The fibrosis grade was 2 (1, 3), 3 (2, 3), and 3 (2, 3), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=11.078, P=0.004). Post hoc analysis revealed that the fibrosis degree was higher in both the stent-surgery group and the stent- neoadjuvant chemotherapy-surgery group compared with the emergency surgery group (both, P<0.05). The tumor cell ratio grades were 4 (3, 4), 4 (3, 4), and 3 (2, 4), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=8.594, P=0.014). Post hoc analysis showed that the tumor cell ratio in the stent-neoadjuvant chemotherapy-surgery group was significantly lower than that in the emergency surgery group (P=0.012). The CD34 grades were 2 (2, 3), 3 (2, 4), and 3 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, and the difference was statistically significant (H=9.786, P=0.007). Post hoc analysis showed that the CD34 grades in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups were 2 (2, 3), 3 (2, 4), and 3 (2,3), respectively. Post hoc analysis revealed that the CD34 concentration was higher in the stent-surgery group than that in the emergency surgery group (P=0.005). Conclusion: Stenting may increase the risk of distant metastases in obstructive colorectal cancer. The stent-neoadjuvant chemotherapy-surgery treatment model promotes tumor cell necrosis and fibrosis and reduces the proportion of tumor cells, vascular infiltration, and peripheral nerve infiltration, which may help decrease local tumor infiltration and distant metastasis in completely obstructive colorectal cancer after stent placement.

[Short-term efficacy of laparoscopic sleeve gastrectomy plus uncut jejunojejunostomy (SG-uncut JJB) for treatment of obesity: a prospective study]

Objective: To analyze the short-term efficacy of sleeve gastrectomy plus uncut jejunojejunostomy (SG+uncut JJB) for patients with obesity. Methods: This prospective study was conducted in the General Surgery Department of Beijing Chaoyang Hospital from January to December 2020 (NCT04534504). The inclusion criteria were patients with a body mass index (BMI) of >32.5 kg/m², type 2 diabetes mellitus (T2DM) or at least two comorbidities with a BMI of 27.5-32.5 kg/m², a waist circumference of >90 cm (male) or >85 cm (female), and those aged between 16 and 65 years. The exclusion criteria included patients who were pregnant, diagnosed with severe neurological or mental illnesses, long-term users of antidepressants and immunosuppressants, and diagnosed with severe gastroesophageal reflux disease or underwent revision surgery. Patients with incomplete follow-up data or insufficient follow-up time were also excluded. Patients were divided into SG-uncut JJB group and SG group according to doctor's recommendation and patients' wills. The primary endpoint was the percentage of excess weight loss (%EWL), and the secondary endpoints were the percentage of total weight loss (%TWL) and the T2DM remission rate. All patients were regularly followed up until the end of December 2020. Results: After excluding seven patients who did not meet the inclusion criteria, 47 eligible patients were finally identified, with 21 in the SG+uncut JJB group and 26 in the SG group. The operation time (140 [110-180] minutes vs. 90 [70-180] minutes, Z=-3.642, P=0.001) and total cost ([54,000 ± 6000] yuan vs. [49,000 ± 7000] yuan, t=2.590, P=0.013) were slightly higher in the SG+uncut JJB group than in the SG group (all P<0.05). However, no significant differences were observed in terms of postoperative hospital stay, operative blood loss, and postoperative complications between the two groups (all P>0.05). The incidence of nausea and vomiting was significantly lower in the SG+uncut JJB group than in the SG group (9.5% [2/21] vs. 46.2% [12/26], χ²=7.453, P=0.006}. The %EWL and %TWL in the SG+uncut JJB group tended to increase gradually with time. The same trend was also observed in the SG group during the first 6 months of follow-up. The 12-month %EWL and %TWL in the SG group were slightly lower compared with the 6-month %EWL and %TWL (P=0.001). The 12-month %EWL values in the SG+uncut JJB and SG groups were (72.4%±12.3%) and (63.6%±25.7%), respectively. However, no significant differences were observed between the two groups in terms of %EWL. Moreover, the 1-month ([11.1%±2.4%] vs. [8.2%±4.4%], P=0.011) and 12-month %TWL ([29.7%±6.9%] vs. [20.3%±7.2%], P=0.001) were significantly higher in the SG+uncut JJB group than in the SG group. No significant differences were observed in terms of T2DM and hypertension remission (all P>0.05). Conclusion: SG+uncut JJB might achieve a promising weight-loss effect similar to SG with a relatively lower incidence of postoperative nausea and vomiting, and it might be an effective and safe approach for obesity management.

[Current management status of hereditary colorectal cancer]

Hereditary colorectal cancer accounts for approximately 5% of all colorectal cancer cases, mainly including familial adenomatous polyposis and Lynch syndrome. Total proctocolectomy plus ileal pouch-anal anastomosis and total colectomy plus ileorectal anastomosis are two major procedures for familial adenomatous polyposis, however, the exact impact of these two procedures on surgical efficacy, oncologic efficacy as well as functional results still remains uncertain. Segmental colectomy and total colectomy are two major procedures for Lynch syndrome, each of them both has advantages and disadvantages, and there still lacks a consensus about the optimal strategy because of the nature of retrospective study with a relatively insufficient evidence support. As a result, we would make a review about the current surgical treatment status and future perspectives of hereditary colorectal cancer.

[The current status and future perspectives of bariatric and metabolic surgery in the management of obesity and its co-morbidities]

Bariatric-metabolic surgery (BMS) has the potential of decreasing body weight and improving obesity-related metabolic syndrome by restricting food intake and malabsorption. Laparoscopic sleeve gastrectomy, Roux-en-Y gastric bypass, adjustable gastric banding, biliopancreatic diversion with duodenal switch are four major BMS procedures. Sleeve plus surgery, one-anastomosis gastric bypass, intragastric balloon and endoscopic surgery are also arising and gaining popularity due to their specific efficacy. Currently, BMS is now experiencing an era with deeply integrated interdisciplinarity, optimizing and innovating of surgeries and well-illustrated clinical efficacy, as a result, more obese patients would benefit from BMS.

[Biological mesh versus primary closure for pelvic floor reconstruction following extralevator abdominoperineal excision: a meta-analysis]

Objective: To compare the morbidity of perineum-related complication between biological mesh and primary closure in closing pelvic floor defects following extralevator abdominoperineal excision (ELAPE). Methods: A literature search was performed in PubMed, Embase, Cochrane Library, Web of Science, Wanfang database, Chinese National Knowledge Infrastructure, VIP database, and China Biological Medicine database for published clinical researches on perineum-related complications following ELAPE between January 2007 and August 2020. Literature inclusion criteria: (1) study subjects: patients undergoing ELAPE with rectal cancers confirmed by colonoscopy pathological biopsy or surgical pathology; (2) study types: randomized controlled studies or observational studies comparing the postoperative perineum-related complications between the two groups (primary perineal closure and reconstruction with a biological mesh) following ELAPE; (3) intervention measures: biological mesh reconstruction used as the treatment group, and primary closure used as the control group; (4) outcome measures: the included literatures should at least include one of the following postoperative perineal complications: overall perineal wound complications, perineal wound infection, perineal wound dehiscence, perineal hernia, chronic sinus, chronic perineal pain (postoperative 12-month), urinary dysfunction and sexual dysfunction. Literature exclusion criteria: (1) data published repeatedly; (2) study with incomplete or wrong original data and unable to obtain original data. Two reviewers independently performed screening, data extraction and assessment on the quality of included studies. Review Manager 5.3 software was used for meta-analysis. The mobidities of perineum-related complications, including overall perineal wound (infection, dehiscence, hernia, chronic sinus) and perineal chronic pain (postoperative 12-month), were compared between the two pelvic floor reconstruction methods. Finally, publication bias was assessed, and sensitivity analysis was used to evaluate the stability of the results. Results: A total of five studies, including two randomized controlled studies and three observational controlled studies, with 650 patients (399 cases in the biological mesh group and 251 cases in primary closure group) were finally included. Compared with primary closure, biological mesh reconstruction had significantly lower ratio of perineal hernia (RR=0.37, 95%CI: 0.21-0.64, P<0.001). No significant differences in ratios of overall perineal wound complication, perineal wound infection, perineal wound dehiscence, perineal chronic sinus and perineal chronic pain (postoperative 12-month) were found between the two groups (all P>0.05). Conclusion: Compared with primary closure, pelvic floor reconstruction following ELAPE with biological mesh has the advantage of a lower incidence of perineal hernia.

[Influencing factors of anastomotic leak after right hemicolon surgery and progress in diagnosis and treatment strategies]

Anastomotic leak is one of the most severe complications following right hemicolectomy but rarely happens, which should be diagnosed based on clinical manifestations, laboratory and radiographic examinations. Influencing factors of anastomotic leak after right hemicolectomy include bowel preparation, emergency surgery, anastomotic procedure (side-to-side anastomosis vs. end-to-side anastomosis, instrument anastomosis vs. manual technigue and intracorporeal vs. extracorporeal anastomosis), surgical resection range and patient's characteristics. The occurrence of anastomotic leak might be avoided by standardized operations and indocyanine green fluorescence imaging. Active treatment is recommended once anastomotic leak is diagnosed. Most patients can be cured by non-surgical treatments such as adequate drainage and anti-infection therapy. When severe sepsis happens or non-surgical treatment fails, surgical treatment should be carried out in time.

[A comparative study of the effects of different treatment strategies on postoperative anal function and quality of life in patients with complete obstructive left hemicolon cancer]

Objective: To compare the effects of 3 treatment strategies (emergent surgery, self-expanding metallic stents, self-expanding metallic stents plus neoadjuvant chemotherapy) on postoperative anal function and quality of life in patients with complete obstructive left hemicolon cancer. Methods: A retrospective cohort study was conducted. Clinical data of patients with complete obstructive left hemicolon cancer admitted to General Surgery Department of Beijing Chaoyang Hospital between January 2017 and October 2019 were retrospectively collected. Patient inclusion criteria: (1) complete obstructive left hemicolon cancer was confirmed through clinical manifestation and abdominal computed tomography; (2) adenocarcinoma was confirmed by postoperative pathology; (3) emergent radical resection of primary tumor was performed with temporary stoma, or radical resection of primary tumor and primary anastomosis was performed without stoma, 7 to 14 days after completion of insertion of self-expanding metallic stents. Patients who did not receive stoma reversion after emergent operation were excluded. According to different therapies, patients were divided into three groups: emergent surgery (ES) group, self-expanding metallic stents (SEMS) group and self-expanding metallic stents plus neoadjuvant chemotherapy (SEMS+NAC) group. Wexner score for incotinence (higher score indicates the worse anal function), Vaizey score (>10 indicates fecal incontinence) and low anterior resection syndrome (LARS) scale (higher score indicates the worse anal function) were applied to evaluate anal function of patients among groups at postoperative 1-, 6- and 12-month. EORTC QLQ-C30 questionnaire was used to assess the quality of life. Risk factors of decreased anal function were identified by logistic regression analysis. Results: A total of 72 patients were enrolled, including 27 (37.5%) patients in ES group, 23 (31.9%) in SEMS group and 22 (30.6%) in SEME+NAC group. The baseline characteristics including age, gender, tumor location, comorbidities, total blood loss, operation time and postoperative complications, were comparable among groups, except that the proportion of laparoscopic surgery was significantly lower in ES group (4/27, 14.9%) than that in SEMS (15/23, 65.2%) and SEMS+NAC group (16/22, 72.7%) with significant difference (P<0.001). The follow-up ended up to October 2020, and the overall follow-up rate was 79.2% (57/72). No significant differences existed in the Wexner score of patients among groups at postoperative 1-, 6- and 12-month (all P>0.05). The Vaizey scores at postoperative 1-month in ES, SEMS and SEMS+NAC group were 7 (0-17), 3 (0-7) and 4 (0-8) respectively with significant difference (H=18.415, P=0.001), and the scores in SEMS and SEMS+NAC groups were significantly lower than that in ES group (both P<0.05), while no significant difference existed between SEMS and SEMS+NAC group (P>0.05). Vaizey scores at postoperative 6- and 12-month among 3 groups were not significantly different (both P>0.05). The LARS scores at postoperative 1-month in ES, SEMS and SEMS+NAC groups were 20 (0-37), 15 (0-24) and 16 (0-28) respectively with significant difference (H=3.660, P=0.036), and the scores in SEMS and SEMS+NAC groups were significantly lower than that in ES group (both P<0.05), while no significant difference existed between SEMS and SEMS+NAC groups (P>0.05). LARS scores at postoperative 6- and 12-month among 3 groups were not significantly different (both P>0.05). The QLQ-C30 score revealed that the social function of patients in SEMS group and SEMS+NAC group was significantly better than that in ES group (both P<0.05), while no significant difference existed between SEMS and SEMS+NAC group (P>0.05). The logistic regression analysis revealed that only ES was an independent risk factor of decreased anal function (OR=2.264, 95% CI: 1.098-4.667, P=0.027). Conclusion: Compared to ES, SEMS may improve quality of life and short-term anal function of patients with complete obstructive left hemicolon cancer.

[Investigation of prevention and treatment of anastomotic bleeding after colorectal surgery]

Anastomotic bleeding is a common complication after colorectal surgery, mainly manifesting as continuous or intermittent bloody stool. The risk factors for anastomotic bleeding mainly include suboptimal surgical skill, surgical methods (such as laparoscopic anastomosis), close distance between the tumor and the anal margin, benign colorectal diseases, anastomotic leakage after colorectal surgery, severe pelvic and abdominal infections, and the patient's own condition, etc. Anastomotic bleeding can be prevented by standardized operation and intraoperative endoscopic examination. Anastomotic bleeding is mostly a self-limited disease, which can be cured by conservative treatments such as fluid resuscitation, blood transfusion and endoscopic treatment. When serious anastomotic bleeding threatens the life of patients, surgical treatment should be taken into consideration decisively.

[Long-term effect of anal fistula plug treatment on postoperative anal function in patients with trans-sphincteric perianal fistula and risk factors associated with anal function]

Objective: To evaluate the long-term effects of anal fistula plug treatment on postoperative anal function in patients with trans-sphincteric perianal fistula, and identify risk factors associated with anal function. Methods: A case-control study was conducted. Clinical and follow-up data of 123 patients with trans-sphincteric perianal fistula receiving anal fistula plug treatment in Beijing Chaoyang Hospital from August 2008 to September 2012 were retrospectively analyzed. The follow-up deadline was April 30, 2020. The Wexner score for incontinence was used to evaluate pre-and postoperative anal function (range from 0 to 20, with higher score representing worse function). The potential risk factors affecting postoperative anal function, including gender, age, fasting blood glucose, diabetes, smoking, alcoholism, location of external opening of anal fistula, surgeon expertise and operation time, were statistically analyzed. Results: Among the 123 patients, 114 were male and 9 were female, the median age was 39 (15-69) years, body mass index (BMI) was (26.2±3.9) kg/m(2), and the median distance between the external opening of anal fistula and the anal verge was 2.6 (1.0-5.0) cm. The median operation time was 30.4 (15.0-60.0) minutes. The median follow-up time was 120 (93-141) months. Sixty-nine patients (56.5%) were healed. The assessment of anal function by Wexner incontinence score showed that 33 (26.8%) patients had anal functional decline after surgery, and the postoperative median Wexner score was 1.34 (0-8), which was significantly higher than preoperative score of 0.17 (0-4) (Z=-5.057, P<0.001). Compared with preoperative levers, postoperative subscores of flatus incontinence, liquid incontinence, solid incontinence and alteration in lifestyle were increased significantly (all P<0.05). Subgroup analysis showed that both in the healed and unhealed groups, the postoperative Wexner scores were higher than those before surgery [healed group: 1.22 (0-8) vs. 0.17 (0-1), Z=-3.796, P<0.001; unhealed group: 1.5 (0-8) vs.0.17 (0-3), Z=-3.422, P=0.001]. Univariate analysis revealed that 33 patients with postoperative anal functional decline had higher BMI, higher fasting blood glucose, higher proportion of alcoholism, longer distance between external opening of anal fistula and the anal verge, and longer operation time (all P<0.05). Multivariate logistic regression analysis testified that higher BMI (OR=1.485, 95% CI: 1.220-1.807, P<0.001) and longer distance between external opening and anal verge (OR=2.207, 95% CI: 1.276-3.220, P=0.003) were independent risk factors for postoperative anal functional decline. Conclusions: The treatment for trans-sphincteric anal fistula with anal fistula plug leads to long-term postoperative anal function decline. For patients with obesity and longer distance between external opening of anal fistula and the anal verge, this procedure should be performed with particular caution, and the anal sphincter should be preserved as much as possible during the operation.

[Gunsight closure versus purse-string closure techniques in loop stoma reversal: a multicenter prospective randomized controlled trial]

Objective: To compare the wound healing time, Surgical site infection (SSI) rate and other postoperative outcomes between the gunsight closure and purse-string closure technique in loop stoma closure. Methods: Between November 2013 and December 2017, a total of 143 patients who underwent gunsight stoma reversal were included in this multicenter prospective randomized controlled trial. The patients were randomized to undergo gunsight (gunsight group, n=72) or purse-string closure technique (purse-string group, n=71). The primary endpoint was wound healing time. The second endpoints were the incidence of SSI, morbidity, and patient satisfaction. Statistical analysis between groups was performed using the t-test, repeated measures analysis of variance, Mann-Whitney U test, χ(2) test or Fisher's exact test. Results: There were 45 males and 27 females with age of 67 (11) (M(Q(R))) years in gunsight group, 42 males and 29 females with age of 65 (20) years in purse-string group. The body mass index, American Society of Anesthesiologist classification, comorbidities, primary diagnosis, the type of ostomy, intraoperative blood loss, perioperative complications, postoperative hospital stay, hospitalization cost, SSI rate and incisional hernia (stoma site) between the 2 groups were not significantly different (P>0.05). Although had a statistically longer operating time (80(10) minutes vs. 70(10) minutes, Z=-2.381, P=0.017), patients who underwent gunsight procedure and a significantly shorter wound healing time (17(2) days vs. 25(4) days, Z=-10.199, P<0.01), higher patient satisfaction score with regards to wound healing time (3(1) vs. 3(1), Z=-4.526, P<0.01), and higher total patient satisfaction score (25(3) vs. 25(3), Z=-2.529, P=0.011) compared with those who underwent purse-string procedure. Conclusions: The gunsight and purse-string techniques are effective procedures for stoma reversal and both have low SSI rate. The gunsight technique is associated with shorter wound healing time, higher levels of patient satisfaction compared with purse-string technique, and is recommended as the closure technique of choice.

[Comparison of short-term efficacy and perioperative safety between neoadjuvant therapy and total neoadjuvant therapy in patients with locally advanced rectal cancer]

Objective: To compare the short-term efficacy and perioperative safety of neoadjuvant chemoradiotherapy (nCRT) with total neoadjuvant treatment (TNT) in patients with locally advanced rectal cancer (LARC). Methods: A retrospective cohort analysis was carried out. Inclusion criteria: (1) rectal adenocarcinoma confirmed by pathology with a distance from tumor inferior border to anal verge within 12 cm; (2) clinical stage cT3-4N0 or cT1-4N1-2 diagnosed by magnetic resonance imaging (MRI) or endorectal ultrasonography; (3) a single rectal tumor confirmed by colonoscopy; (4) patients suitable for chemoradiotherapy; (5) no previous history of other tumors. Exclusion criteria: (1)patients with previous rectal cancer surgery and local recurrence; (2) those who did not complete nCRT course; (3) those with distant metastases; (4) those with defective clinicopathological data. According to the above criteria, a total of 134 LARC patients at the Department of General Surgery of Beijing Chaoyang Hospital from January 2016 to January 2019 were enrolled, including 82 males and 52 females, with a male-female ratio of 1.58∶1.00 and mean age of (59.6±11.2) (26-81) years. Based on neoadjuvant regimen, patients were divided into nCRT group (n=55) and TNT group (n=79). There were no statistically significant differences in baseline data, such as age, sex, distance from tumor to anal verge, Eastern Cooperative Oncology Group (ECOG) performance status and clinical TNM stage, between the two groups (all P>0.05). All the patients received pelvic intensity-modulated radiotherapy (IMRT) with a total dose of 50.4 Gy in 28 fractions. Patients in nCRT group received oral capecitabine chemotherapy during radiotherapy and underwent surgery 6-8 weeks after chemoradiation. Patients in TNT group received one cycle of induction CapeOX (oxaliplatin and capecitabine) and concurrent chemoradiotherapy, then underwent a radical surgery two weeks after completion of consolidation chemotherapy. The efficacy of neoadjuvant therapy, adverse events of chemoradiotherapy and perioperative safety were compared between the two groups. Results: Patients of two groups completed the course of neoadjuvant therapy. There were no statistically significant differences between nCRT group and TNT group in the incidence of adverse events in neutropenia [7.3% (4/55) vs. 10.1% (8/79)], anemia [3.6% (2/55) vs. 3.8% (3/79)], thrombocytopenia [5.5% (3/55) vs. 7.6% (6/79)], gastrointestinal dysfunction [3.6% (2/55) vs. 6.3% (5/79)] and radiation enteritis [9.1% (5/55) vs. 8.9% (7/79)] (all P>0.05). One hundred and thirty patients completed TME surgery, including 54 patients in nCRT group and 76 patients in the TNT group. Compared with the nCRT group, the proportion of abdominoperineal resection (APR) was higher in the TNT group [31.6% (25/76) vs. 13.0% (7/54), χ(2)=9.382, P=0.009]. No statistically significant differences in morbidity of postoperative complication, operation time, intraoperative blood loss and postoperative hospital stay between the two groups were found (all P>0.05). The distal and circumferential margins were negative in all the patients. Seventeen patients in the TNT group 22.4% (17/76) got pathologic complete response (pCR), which was significantly higher than 7.4% (4/54) in nCRT group (χ(2)=5.217, P=0.022). There were no statistically significant differences in ypTNM classification, perineural invasion and venous invasion between the two groups (all P>0.05). Conclusion: The pCR of TNT is higher than that of nCRT without increasing the incidence of toxicity and complications of radiotherapy and chemotherapy for patients with locally advanced rectal cancer.

Fabrication of biodegradable magnesium matrix composite with ultrafine grains and high strength by adding TiC nanoparticles to Mg-1.12Ca-0.84Zn-0.23Mn (at.%) alloy

Mg-1.12Ca-0.84Zn-0.23Mn (at.%) alloy was reinforced by TiC nanoparticles. After extrusion ultra-fine grains of ∼0.4 μm were caused by Zener pinning effect of nano-sized particles including fine precipitated MgZn₂ phases, α-Mn particles and TiC nanoparticles. Yield strength of 423.6 MPa along with ultimate tensile strength of 436.8 MPa could meet biomedical application.

[Long-term efficacy of bioprosthetic anal fistula plug in the treatment of transsphincteric anal fistula]

Objective: To evaluate the long-term healing rate of transsphincteric anal fistula treated with anal fistula plug procedure and the risk factors affecting the healing of anal fistula. Methods: A retrospective case-control study was conducted to analyze the clinical data of 207 patients with transsphincteric anal fistulas who received anal fistula plug procedure at the Department of General Surgery, Beijing Chaoyang Hospital of Capital Medical University from August 2008 to September 2012. Inclusion criteria: (1) consistent with the diagnosis of transsphincteric anal fistula: the anal fistula passed through the internal and external sphincter; (2) complete data; (3) initial treatment with anal fistula plug procedure. Exclusion criteria: (1) acute rectal or perianal infection or poorly controlled focal infection; (2) recent incision and drainage of perianal abscess or spontaneous rupture of abscess; (3) patients with malignant tumor; (4) patients with Crohn's disease or ulcerative colitis; (5) patients with heart, liver, brain, lung or renal insufficiency; (6) cachexia due to various chronic wasting diseases; (7) patients could not tolerate surgery. Patients were followed up for anal fistula healing. The cumulative healing rate of patients with transsphincteric anal fistula was plotted using the Kaplan-Meier method, and the factors affecting anal fistula healing were explored by univariate and multivariate logistic regression analysis. Results: There were 186 males and 21 females with age of 15 to 69 (mean 38) years. The duration of anal fistula was 3-60 (mean 15) months. Three patients had a history of previous episodes of perianal abscess and underwent incision and drainage of perianal abscess (all more than 3 months). During follow-up ending on October 31, 2018, 72 patients (34.8%) were lost to follow-up. Among 135 patients who were successfully followed up, the average follow-up period was 96 (75-124) months. Seventy-five patients had anal fistula healing, with healing rate of 55.6%. Kaplan-Meier survival curve showed that the healing time of anal fistula was prolonged and finally stabilized at 55.6%. In the patients who failed initial treatment with anal fistula plug packing, there were 6 cases whose anal fistula healed spontaneously without other treatment. Among them, 3 cases healed spontaneously 2 years and 3 cases 3 years after operation without recurrence. From 2008 to 2012, the annual healing rates of anal fistula plug treatment were 3/6, 61.5% (24/39), 42.1% (24/57), 12/15 and 12/18, respectively. Multivariate logistic regression analysis showed that the duration of anal fistula≥6 months (OR=3.187, 95% CI: 1.361-7.466, P=0.008) was an independent risk factor for anal fistula healing after treatment with anal fistula plug. Conclusion: The long-term efficacy of anal fistula plug procedure in the treatment of transsphincteric anal fistula is positive, and this procedure should be implemented as soon as possible.

[The status analysis of diagnosis and treatment of synchronous peritoneal carcinomatosis from colorectal cancer in China: a report of 1 003 cases in 16 domestic medical centers]

Objective: To analyze the status of domestic surgical treatment of synchronous peritoneal carcinomatosis from colorectal cancer in China. Methods: Clinicopathological data of patients who underwent surgery from October 2003 to October 2018 in 16 domestic medical centers was retrospectively analyzed. Excel database was created which covered 77 fields of 7 parts: baseline information of patients, laboratory tests, imaging tests, chemoradiotherapy information, intra-operative findings, postoperative pathology and follow-up data. The Wilcoxon rank-sum test was used for comparison of the measurement data between groups. The χ(2) test was used for comparison of the categorical data between groups. The survival curve was calculated by the Kaplan-Meier method. Results: Of the 1 003 patients, there were 575 male and 428 female patients with the age of (58.5±14.1) years (range: 18 to 92 years). In a total of 920 patients, the carcinoma of sigmoid colon was performed in 292 cases (31.8%) with the highest ratio. The proportion of patients with liver metastasis and lung metastasis were 27.9% (219/784) and 8.3% (64/769). Preoperative detection of carcino-embryonic antigen level was the most common method in China (87.74%, 880/1 003), and the positive rate was 64.5% (568/880). The correct rate of preoperative imaging tests was 40.7% (280/688). The ratio of peritoneal carcinomatosis index (PCI) scores between 0 and 10 was the highest (59.6%, 170/285). Two hundred and sixty-two (27.0%) patients were performed by totally laparoscopic operation in 971 patients. The resection of primary tumor was performed in 588 of the 817 patients (72.0%). In a total of 457 cases, 253 (55.4%) patients were performed cytoreduction which group scored completeness of cytoreduction (CCR) 0. The postoperative hyperthermic intraperitoneal chemotherapy was implemented in 70 of the 334 cases (21.0%). Among 1 003 cases, 562 cases (56.03%) had complete follow-up data and the median overall survival was 15 months. The primary tumor resection and the CCR scores were affected by the PCI scores. The patients underwent primary tumor resection (187/205 vs. 26/80, χ(2)=105.085, P=0.000) and the patients were performed cytoreduction which scored CCR 0 or CCR 1 (162/204 vs. 8/78, Z=-10.465, P=0.000) had significant difference between the groups of PCI<20 and ≥20. There was a close correlation between the surgical method and the CCR scores (Z=-3.246,P=0.001).When the maximum degree of tumor reduction was planned, most surgeons would choose laparotomy. The overall survival time was longer in patients with primary tumor resection (P=0.000). The median survival time was 18.6 months in the group of primary tumor resection. Conclusions: It is difficult to diagnose the synchronous peritoneal carcinomatosis from colorectal cancer before the operation. Primary tumor resection has an obvious effect to prolong the survival time. It is necessary to standardize the treatment of peritoneal metastasis.

Ligation of the intersphincteric fistula tract plus a bioprosthetic anal fistula plug (LIFT-Plug): a new technique for fistula-in-ano

AIM

Ligation of the intersphincteric fistula tract and reinforcement with a bioprosthetic graft are two recently reported procedures that have shown promise in the treatment of anal fistula. This study was undertaken to validate combining ligation of the intersphincteric fistula tract plus bioprosthetic anal fistula plug and report our preliminary results and experience.

METHOD

Twenty-one patients with transsphincteric anal fistula were treated with ligation of the intersphincteric fistula tract plus concurrent bioprosthetic plug of the anal fistula. We evaluated healing time, fistula closure rate and postoperative anal function according to the Wexner continence score.

RESULTS

No mortality or major complications were observed. Median operative time was 20 (range 15-40) min. After a median follow-up of 14 (range 12-15) months, the overall success rate was 95% (20/21), with a median healing time of 2 (range 2-3) weeks for external anal fistula opening and 4 (range 3-7) weeks for intersphincteric groove incision. Only 1 (5%) patient reported rare incontinence for gas postoperatively (Wexner score 1).

CONCLUSIONS

Ligation of the intersphincteric fistula tract plus a bioprosthetic anal fistula plug is an easy, safe, effective and useful alternative in the management of anal fistula. Further randomized controlled studies are necessary to better evaluate long-term results.

Rangeland degradation and restoration management in China

Rangelands of China have for centuries provided forage for livestock but now their role in water, soil, and biodiversity conservation is being recognised by Governments and people. However, much of the rangelands has recently degraded and desertification is now a widespread problem. The cause of the degradation is over-grazing and over-cultivation. Climate change is exacerbating the problem. The Chinese Governments have begun to address these severe problems through policy adjustments and projects. In parallel, some research and development is taking place. There are major impediments to addressing the problem; the importance of rangelands to China and its people are generally underestimated, legislative protection is incomplete and often ineffective, little attention is paid to scientific knowledge for development of management of natural resources, there is insufficient technological support, and Governments are not able to invest sufficiently to effectively restore and develop rangeland natural resources. However, with this background we propose how the problems might be more effectively addressed in the future.

Operative treatment of ventral hernia using prosthetic materials

OBJECTIVE

The objective of this study was to summarize the clinical experiences in repairing abdominal incisional hernia with prosthetic materials.

METHODS

Eighty-three patients with ventral hernia were analyzed retrospectively.

RESULTS

Two patients developed pulmonary infection, one developed adhesive ileus, and five developed wound infection. All wounds healed completely during follow-up. Seventy-three (88%) patients were free of pain, and ten patients (12%) felt pain in the operated area within the last month; only one patient required pain-relieving drugs. Twenty-nine patients (35%) felt discomfort, such as stiffness. Four cases experienced postoperative recurrence.

CONCLUSIONS

Incisional herniorrhaphy with prosthetic materials is safe and effective but has a high discomfort rate. Open giant incisional hernia or recurrent incisional hernia should be performed by trained surgeons. Placing mesh in a suitable position and using a patch with minimal reaction and enough tensile strength may improve the prognosis. Further studies are necessary utilizing light polypropylene mesh.

Scoring protein-protein docked structures based on the balance and tightness of binding

One main issue in protein-protein docking is to filter or score the putative docked structures. Unlike many popular scoring functions that are based on geometric and energetic complementarity, we present a set of scoring functions that are based on the consideration of local balance and tightness of binding of the docked structures. These scoring functions include the force and moment acting on one component (ligand) imposed by the other (receptor) and the second order spatial derivatives of protein-protein interaction potential. The scoring functions were applied to the docked structures of 19 test targets including enzyme/inhibitor, antibody/antigen and other classes of protein complexes. The results indicate that these scoring functions are also discriminative for the near-native conformation. For some cases, such as antibody/antigen, they show more discriminative efficiency than some other scoring functions, such as desolvation free energy (deltaG(des)) based on pairwise atom-atom contact energy (ACE). The correlation analyses between present scoring functions and the energetic functions also show that there is no clear correlation between them; therefore, the present scoring functions are not essentially the same as energy functions.

[The regulation activity of Chlorella virus gene 5' upstream sequence in Escherichia coli and eucaryotic alage]

The 5' upstream regions of adenine methyltransgerase gene and major coat protein gene (PAMT, PVP54) in Chlorella virus genomes were used to contract transformation vectors in E. coli and eukaryotic algae. The regulation activities of PAMT and PVP54 comparing with PRPL and CaMV35S promoters were analyzed in different E. coli strains and Chlorella species. It is found that the luciferase activity controlled by PAMT is 50-400 times higher than that controlled by PRPL. The regulation activity of PAMT in 2 Chlorella species is obviously higher than that of CaMV35S promoter. It is the first report that the 5' upstream region of Chlorella virus gene has strong regulation activity in eucaryotic algae. The result suggests this regulation sequence will have an excellent application in the eucaryotic algae genetic engineering.