Contemporary review of minimally invasive pancreaticoduodenectomy

AIM To assess the current literature describing various minimally invasive techniques for and to review short-term outcomes after minimally invasive pancreaticoduodenectomy(PD). METHODS PD remains the only potentially curative treatment for periampullary malignancies, including, most commonly, pancreatic adenocarcinoma. Minimally invasive approaches to this complex operation have begun to be increasingly reported in the literature and are purported by some to reduce the historically high morbidity of PD associated with the open technique. In this systematic review, we have searched the literature for high-quality publications describing minimally invasive techniques for PD-including laparoscopic, robotic, and laparoscopicassisted robotic approaches(hybrid approach). We have identified publications with the largest operative experiences from well-known centers of excellence for this complex procedure. We report primarily short term operative and perioperative results and some short term oncologic endpoints. RESULTS Minimal y invasive techniques include laparoscopic, robotic and hybrid approaches and each of these techniques has strong advocates. Consistently, across all minimally invasive modalities, these techniques are associated less intraoperative blood loss than traditional open PD(OPD), but in exchange for longer operating times. These techniques are relatively equivalent in terms of perioperative morbidity and short term oncologic outcomes. Importantly, pancreatic fistula rate appears to be comparable in most minimally invasive series compared to open technique. Impact of minimally invasive technique on length of stay is mixed compared to some traditional open series. A few series have suggestedthat initiation of and time to adjuvant therapy may be improved with minimally invasive techniques, however this assertion remains controversial. In terms of shortterms costs, minimally invasive PD is significantly higher than that of OPD. CONCLUSION Minimally invasive approaches to PD show great promise as a strategy to improve short-term outcomes in patients undergoing PD, but the best results remain isolated to high-volume centers of excellence.

Continuous suture of the pancreatic stump and Braun enteroenterostomy in pancreaticoduodenectomy

AIM:To investigate a new modification of pancreaticoduodenectomy(PD)-a mesh-like running suturing of the pancreatic remnant and Braun's enteroenterostomy.METHODS:Two hundred and three patients underwent PD from 2009 to 2014 and were classified into two groups:Group A(98 patients),who received PD with a mesh-like running suturing for the pancreatic remnant,and Braun's enteroenterostomy; and Group B(105 patients),who received standard PD.Demographic data,intraoperative findings,postoperative morbidity and perioperative mortality between the two groups were compared by univariate and multivariate analysis.RESULTS:Demographic characteristics between Group A and Group B were comparable.There were no significant differences between the two groups concerning perioperative mortality,and operative blood loss,as well as the incidence of the postoperative morbidity,including reoperation,bile leakage,intraabdominal fluid collection or infection,and postoperative bleeding.Clinically relevant postoperative pancreatic fistula(POPF) and delayed gastric emptying(DGE) were identified more frequently in Group B than in Group A.Technique A(PD with a mesh-like running suturing of the pancreatic remnant and Braun's enteroenterostomy) was independently associated with decreased clinicallyrelevant POPF and DGE,with an odds ratio of 0.266(95%CI:0.109-0.654,P =0.004) for clinically relevant POPF and 0.073(95%CI:0.010-0.578,P =0.013) for clinically relevant DGE.CONCLUSION:An additional mesh-like running suturing of the pancreatic remnant and Braun's enteroenterostomy during PD decreases the incidence of postoperative complications and is beneficial for patients.

A subset of ulcerative colitis with positive proteinase-3 antineutrophil cytoplasmic antibody

A small subset of patients with active ulcerative colitis is non-responsive to major known non-biological therapies. We reported 5 patients with positive serum proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) and tried to (1) identify the common clinical features of these patients; (2) investigate the efficacy of a novel therapy using a Chinese medicine compound; and (3) attract more gastroenterologists to be engaged in further study of this subset of patients. The common manifestations of disease in these 5 patients included recurrent bloody diarrhea and inflammatory lesions involving the entire colorectal mucosa. Initial treatment with intravenous methylprednisolone successfully induced remission. Four of these 5 patients were steroid-dependence, and immunosuppressants, such as azathioprine and cyclophosphamide, were in effective. In 3 patients, only the particular Chinese medicine compound could induce and maintain remission. One patient underwent colectomy. No vascular inflammatory lesions were found by histopathological examination. Although more cases are needed for confirmation, our study indicates thatulcerative colitis with positive PR3-ANCA may belong to a subtype of refractory ulcerative colitis. The particular Chinese medicine compound used in our study is by far the most effective in the management of these patients, with additional advantages of having no noticeable side-effects and less financial burden.

SYSTEM FOR AUTOMATIC GENERALIZATION OF TOPOGRAPHIC MAPS

With the construction of spatial data infi＇astructure, automated topographic map generalization becomes an indispensable component in the community of cartography and geographic information science. This paper describes a topographic map generalization system recently developed by the authors. The system has the following characteristics： 1） taking advantage of three levels of automation, i.e. fully automated generalization, batch generalization, and interactive generalization, to undertake two types of processes, i.e. intelligent inference process and repetitive operation process in generalization; 2） making use of two kinds of sources for generalizing rule library, i.e. written specifications and cartographers＇ experiences, to define a six-element structure to describe the rules; 3） employing a hierarchical structure for map databases, logically and physically; 4） employing a grid indexing technique and undo/redo operation to improve database retrieval and object generalization efficiency. Two examples of topographic map generalization are given to demonstrate the system. It reveals that the system works well. In fact, this system has been used for a number of projects and it has been found that a great improvement in efficiency compared with traditional map general- ization process can be achieved.

Mapping of Soil Erosion Zones of Meghadrigedda Catchment, Visakhapatnam, India for Conservation <br/>—A Geospatial Approach

Meghadrigedda, a non-perennial drainage system is one of the major water resources of Vishakhapatnam city located in the northern coastal region of Andhra Pradesh, India. It traverses through the hilly terrain of Eastern GhatMobile Belt (EGMB) characterized by khondalitic rock formations. Excessive siltation scenario aggravated due to soil erosion in its catchment is threatening the very existence of Meghadrigedda reservoir. In order to assess the intensity of soil erosion as well as silt deposition in the reservoir, an integrated study has been undertaken which takes into consideration various topographic, morphological, soil, and land use/land cover characteristics of the basin. The study aims at identification and mapping of erosion prone zones with respect to silt deposition using remote sensing and GIS techniques.Alteration in human induced land use practices in its catchment due to rapid growth in population, urbanization and industrialization are found to be of prime reasons for various forms of erosion. The study has noticed that various forms of erosion like sheet, gully and stream erosion are responsible for the siltation at large scale which is causing reduction of its designed storage capacity by 40%. Various sub-watersheds of the basin have been prioritized on the basis of erosion intensity for suggesting various mitigation measures like check-dam construction, afforestation etc. to protect the reservoir from the silting problem.

Incidence and treatment of mediastinal leakage after esophagectomy:Insights from the multicenter study on mediastinal leaks

BACKGROUND Mediastinal leakage(ML) is one of the most feared complications of esophagectomy. A standard strategy for its diagnosis and treatment has beendifficult to establish because of the great variability in their incidence and mortality rates reported in the existing series.AIM To assess the incidence, predictive factors, treatment, and associated mortality rate of mediastinal leakage using the standardized definition of mediastinal leaks recently proposed by the Esophagectomy Complications Consensus Group(ECCG).METHODS Seven Italian surgical centers(five high-volume, two low-volume) affiliated with the Italian Society for the Study of Esophageal Diseases designed and implemented a retrospective study including all esophagectomies(n = 501) with intrathoracic esophagogastric anastomosis performed from 2014 to 2017.Anastomotic MLs were defined according to the classification recently proposed by the ECCG.RESULTS Fifty-nine cases of ML were recorded, yielding an overall incidence of 11.8%(95%CI: 9.1%-14.9%). The surgical approach significantly influenced the occurrence of ML: the proportion of leakage was 10.5% and 9% after open and hybrid esophagectomy(HE), respectively, and doubled(20%) after totally minimally invasive esophagectomy(TMIE)(P = 0.016). No other predictive factors were found. The 30-and 90-d overall mortality rates were 1.4% and 3.2%,respectively; the 30-and 90-d leak-related mortality rates were 5.1% and 10.2%,respectively; the 90-d mortality rates for TMIE and HE were 5.9% and 1.8%,respectively. Endoscopy was the first-line treatment in 49% of ML cases, with the need for retreatment in 17.2% of cases. Surgery was needed in 44.1% of ML cases.Endoscopic treatment had the lowest mortality rate(6.9%). Removal of the gastric tube with stoma formation was necessary in 8(13.6%) cases.CONCLUSION The incidence of ML after esophagectomy was high mainly in the TMIE group.However, the general and specific(leak-related) mortality rates were low. Early treatment(surgical or endoscopic) of severe leaks is mandatory to limit related mortality.

A simulation-based optimization approach for passenger train timetabling with periodic track maintenance and stops for praying

This paper presents two optimization methods for solving the passenger train timetabling problem to minimize the total delay time in the single track railway networks. The goal of the train timetable problem is to determine departure and arrival times to or from each station in order to prevent collisions between trains and effective utilization of resources. The two proposed methods are based on integration of a simulation and an optimization method to simulate train traffic flow and generate near optimal train timetable under realistic con- straints including stops for track maintenance and praying. The first proposed method integrates a cellular automata （CA） simulation model with genetic algorithm optimiza- tion method. In the second proposed approach, a CA simulation model combines with dynamically dimensioned search optimization method. The proposed models are applied to hypothetical case study to demonstrate the merit of them. The Islamic Republic of Iran Railways （IRIR） data and regulations have been used to optimize train timetable. The results show the first method is more effi- cient than the second method to obtain near optimal train timetabling.

Correlation of intestinal disaccharidase activities with the C/T_(-13910) variant and age

AIM： To correlate the C/T-13910 variant, associated with lactase persistence/non-persistence （adulttype hypolactasia） trait, with intestinal disaccharidase activities in different age groups of the adult population.METHODS： Intestinal biopsies were obtained from 222 adults aged 18 to 83 years undergoing upper gastrointestinal endoscopy because of unspecified abdominal complaints. The biopsies were assayed for lactase, sucrase and maltase activities and genotyped for the C/T-13910 variant using PCR-minisequencing. RESULTS： There was a significant correlation between lactase activity and the C/T-13910 variant （P 〈 0.00001）. The mean level of lactase activity among subjects with C/C-1391o genotype was 6.86± 0.35 U/g, with C/T-13910 genotype 37.8 ± 1.4 U/g, and with T/T-13910 genotype 57.6± 2.4 U/g protein, showing a trimodal distribution of this enzyme activity. Significant differences were also observed in maltase activities among individuals with different C/T-13910 genotypes （P = 0.005）. In contrast, in sucrase activity, no significant differences emerged between the C/T-13910 genotypes （P = 0.14）. There were no statistical differences in lactase （P = 0.84）, sucrase （P = 0.18）, or maltase activity （P = 0.24） among different age groups. In the majority （〉 84%） of the patients with the C/C-13910 genotype associated with lactase non- persistence, the lactase activity was less than 10 U/g protein.CONCLUSION： Our study demonstrates a statistically significant correlation between the C/T-13910 genotype and lactase activity and this correlation is not affected by age in adults but the cut-off value of 20 U/g protein used for the diagnosis of lactase non-persistence might be too high.

消化道出血对幽门螺杆菌诊断试验的影响:一项出血时和出血后1个月的前瞻性研究

Background: Some case series and cohort studies suggest that acute GI bleeding decreases the sensitivity of Helicobacter pylori diagnostic testing. Objective: To assess H pylori biopsy testing in patients with acute upper-GI bleeding and 1 month later. Design: Prospective cohort study using patients as their own controls. Setting: Urban county hospital. Patients: Sixty-one patients with acute variceal bleeding. Interventions: Antral and body endoscopic biopsies at admission and 1 month later. Main outcome measurements: CLO test and histologic examinations were performed and bi opsy specimens were coded and mixed for blinded histologic examination for H pyl ori density and inflammation. Results: CLO test results changed from H pylori ne gative at baseline to H pylori positive at 1 month in two patients (3%), from H pylori positive to H pylori negative in 6 patients (10%), and remained the sam e in 53 (87%). Histologic results changed from H pylori negative at baseline to H pylori positive at 1 month in two patients (3%), from H pylori positive to H pylori negative in 5 patients (8%),and remained the same in 54 (89%). Changes occurred only in patients with low H pylori density. No significant increase in H pylori density or change in inflammatory cell infiltration was seen. CLO test sensitivity was 8%higher with bleeding vs. 1 month after bleeding (79%vs. 71% ; 95%CI of difference was 11%to 27%; i.e., maximal potential decrease in sens itivity with bleeding is 11%). Limitations: The population is not one for which H pylori testing is recommended, and biopsy test performance was less consisten t than expected. Conclusions: Acute-GI bleeding did not decrease the sensitivit y of rapid urease testing, unless the effect lastsmore than 1 month. Furthermore , bleeding did not produce falsely negative histologic examinations for H pylori , decrease H pylori density, or alter inflammatory cell infiltration. However, g iven the lower than expected overall CLO test sensitivity and frequent use of pr oton pump inhibitors for GI bleeding, histology may be preferred in this setting .