Two big orifices in the second duodenal portion:A case of an atypical double papilla

With the advent of endoscopic retrograde cholangiopancreatography(ERCP)in the early 1970s,anatomic anomalies of the Vaterian system were described endoscopically[1].Although the occurrence is rare,the common bile duct(CBD)and the pancreatic duct may fail to coalesce during embryologic development.This leads to double major papilla because both ducts open into the duodenum separately[1].In this way the cranial duct communicates with the CBD,while the caudal orifice communicates with the pancreatic duct[2].

EXPERIMENTAL INVESTIGATIONS OF CAVITATION EFFECTS ON FLOW CHARACTERISTICS OF SMALL ORIFICES AND VALVES IN WATER HYDRAULICS

The flow characteristics and cavitation effects of water passing throughsmall sharp-edged cylindrical orifices and valves of different shapes in water hydraulics areinvestigated. The test results using orifices with different aspect ratios and different diametersshow that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decreaseas Reynolds number increases and ultimately tend to be of constant values close to contractioncoefficient. Large aspect ratio has an effect of suppressing cavitation. The experimental resultsabout disc valves illustrate that the valves with sharp edge at large opening are less affected bycavitation than that at small opening. Throttle with triangle notch has better anti-cavitationability than that with square notch. The flowrate of the throttle with square notch is significantlyaffected by the flow direction or the flow passage shape.

The role of single deformed bubble on porous foam tray with submerged orifices on the mass transfer enhancement

Foam trays with porous submerged orifices endow bubbles uniformly distributed,which are considered attractive column internals to enhance the gas-liquid mass transfer process.However,its irregular orifice and complex gas-liquid flow make it lack pore-scale investigations concerning the transfer mechanism of dynamic bubbling.In this work,the actual porous structure of the foam tray is obtained based on micro computed tomography technology.The shape,dynamic,and mass transfer of rising bubbles at porous orifices are investigated using the volume of fluid and continue surface force model.The results demonstrate that the liquid encroaching on the gas channels causes the increasing orifices velocity,which makes the trailing bubble easily detach from the midst of the leading bubble and causes pairing coalescence.Additionally,we found that the central breakup regimes significantly improve the gas-liquid interface area and mass transfer efficiency.This discovery exemplifies the mechanism of mass transfer intensification for foam trays and serves to promote its further development.

Influence of cyclic ignition and steady-state operation on a 1–2 A barium tungsten hollow cathode

Booming low-power electric propulsion systems require 1–2 A hollow cathodes.Such cathodes are expected to go through more frequent ignitions in the low orbit,but the impact of cyclic ignitions on such 1–2 A barium tungsten hollow cathodes with a heater was not clear.In this study,a 12,638-cyclic ignition test and a 6,000-hour-long life test on two identical cathodes were carried out.The discharge voltage of the cathode and the erosion of the orifice after cyclic ignition were all larger than that of the cathode after stable operation.This indicated that the impact of cycle ignition on the discharge performance of a low current BaO-W cathode with a heater was higher than that of stable operation.The results of the ion energy distribution function measured during the ignition period indicated that the main reason for the orifice expansion was ion bombardment.Therefore,it was necessary to pay attention to the number of ignitions for the lifetime of this kind of cathode.

Removal of a guide-wire sliding into abdominal cavity via transgastric natural orifice transluminal endoscopic surgery: A case report

BACKGROUND Guidewire slippage into the peritoneal cavity during clinical operations is extremely rare.Therefore,this paper aims to report a successful case of guidewire removal using transgastric natural orifice transluminal endoscopic surgery(NOTES).The goal is to enhance physicians'understanding of the management plan for this unique scenario and provide a valuable reference for clinical practice.CASE SUMMARY A 64-year-old man presented with abdominal distension and was diagnosed with cirrhosis combined with massive ascites.To proceed with treatment,the patient underwent ultrasound-guided peritoneal puncture and underwent catheterization and drainage.Unfortunately,a 0.035-inch guidewire slipped into the abdominal cavity during the procedure.Following a comprehensive evaluation and consultation by a multidisciplinary team,the guidewire was successfully removed using NOTES.CONCLUSION This case highlights the potential consideration of transgastric NOTES removal when encountering a foreign body,such as a guidewire,within the abdominal cavity.

Resection of polyps involving the appendiceal orifice by combined endo-laparoscopic surgery: Two case reports

BACKGROUND The management of polyps involving the appendiceal orifice(AO)presents notable challenges.Endoscopic resection is frequently hindered by operational complexities,a heightened risk of incomplete removal,and an elevated risk of procedural complications,including appendicitis.Conversely,surgical resection may entail unnecessary excision of intestinal segments,leading to potential morbidity.CASE SUMMARY Here,we reported two patients who presented with polyps deeply situated within the AO,with indistinct boundaries making it challenging to ensure completeness using traditional endoscopic resection.To overcome these challenges,we em-ployed combined endo-laparoscopic surgery(CELS),achieving curative resection without postoperative complications.CONCLUSION The application of CELS in managing polyps involving the AO is emerging as a safe and effective treatment modality.

Perioperative outcomes of transvaginal specimen extraction laparoscopic total gastrectomy and conventional laparoscopicassisted total gastrectomy

BACKGROUND Natural orifice specimen extraction surgery(NOSES)has emerged as a promising alternative compared to conventional laparoscopic-assisted total gastrectomy(LATG)for treating gastric cancer(GC).However,evidence regarding the efficacy and safety of NOSES for GC surgery is limited.This study aimed to compare the safety and feasibility,in addition to postoperative complications of NOSES and LATG.METHODS Dual circular staplers were used in Roux-en-Y digestive tract reconstruction for transvaginal specimen extraction LATG,and its outcomes were compared with LATG in a cohort of 51 GC patients with tumor size≤5 cm.The study was conducted from May 2018 to September 2020,and patients were categorized into the NOSES group(n=22)and LATG group(n=29).Perioperative parameters were compared and analyzed,including patient and tumor characteristics,postoperative outcomes,and anastomosis-related complications,postoperative hospital stay,the length of abdominal incision,difference in tumor type,postoperative complications,and postoperative survival.RESULTS Postoperative exhaust time,operation duration,mean postoperative hospital stay,length of abdominal incision,number of specific staplers used,and Brief Illness Perception Questionnaire score were significant in both groups(P<0.01).In the NOSES group,the postoperative time to first flatus,mean postoperative hospital stay,and length of abdominal incision were significantly shorter than those in the LATG group.Patients in the NOSES group had faster postoperative recovery,and achieved abdominal minimally invasive incision that met aesthetic requirements.There were no significant differences in gender,age,tumor type,postoperative complications,and postoperative survival between the two groups.CONCLUSION The application of dual circular staplers in Roux-en-Y digestive tract reconstruction combined with NOSES gastrectomy is safe and convenient.This approach offers better short-term outcomes compared to LATG,while long-term survival rates are comparable to those of conventional laparoscopic surgery.

Analysis of quality of life in patients after transgastric natural orifice transluminal endoscopic gallbladder-preserving surgery

BACKGROUND At present,laparoscopic cholecystectomy(LC)is the main surgical treatment for gallstones.But,after gallbladder removal,there are many complications.Therefore,it is hoped to remove stones while preserving the function of the gallbladder,and with the development of endoscopic technology,natural orifice transluminal endoscopic surgery came into being.AIM To compare the quality of life,perioperative indicators,adverse events after LC and transgastric natural orifice transluminal endoscopic gallbladder-preserving surgery(EGPS)in patients with gallstones.METHODS Patients who were admitted to The First Affiliated Hospital of Xinjiang Medical University from 2020 to 2022 were retrospectively collected.We adopted propen-sity score matching(1:1)to compare EGPS and LC patients.RESULTS A total of 662 cases were collected,of which 589 cases underwent LC,and 73 cases underwent EGPS.Propensity score matching was performed,and 40 patients were included in each of the groups.In the EGPS group,except the gastr-ointestinal defecation(P=0.603),the total score,physical well-being,mental well-being,and gastrointestinal digestion were statistically significant compared with the preoperative score after surgery(P<0.05).In the LC group,except the mental well-being,the total score,physical well-being,gastrointestinal digestion,the gastrointestinal defecation was statistically significant compared with the preoperative score after surgery(P<0.05).When comparing between groups,gastrointestinal defecation had significantly difference(P=0.002)between the two groups,there was no statistically significant difference in the total postoperative score and the other three subscales.In the surgery duration,hospital stay and cost,LC group were lower than EGPS group.The recurrence factors of gallstones after EGPS were analyzed:and recurrence was not correlated with gender,age,body mass index,number of stones,and preoperative score.CONCLUSION Whether EGPS or LC,it can improve the patient’s symptoms,and the EGPS has less impact on the patient’s defecation.It needed to,prospective,multicenter,long-term follow-up,large-sample related studies to prove.

The measurement of internal surface characteristics of fuel nozzle orifices using the synchrotron X-ray micro CT technology

The design of fuel nozzle orifices at micrometer scales is crucial for generating desired fuel spray patterns, and consequently optimizing fuel combustion and emission in internal combustion engines. Although there have been several recent advancements in the characterization of orifice internal geometries, quantitative studies on the orifice internal wall surface characteristics are still challeges due to the lack of effective measuring methods. A new method for quantifying the internal wall surface characteristics of fuel nozzle micro-orifices is presented in this study to achieve a better understanding and prediction of spray characteristics: Firstly, by using the synchrotron X-ray micro CT technology, a three-dimensional digital model of the fuel nozzle tip was constructed. Secondly, a data post-processing technique was then applied to unfold the orifice internal wall surface to a flat base plane. Finally, the conventional surface characteristic quantification techniques can be used to evaluate the wall surface characteristics. Two diesel nozzles with identical orifice geometry design but different hydraulic grinding time were measured using this method. One nozzle was hydro-ground for 2 s while the other was not. The internal wall surfaces of the two orifices were successfully unfolded to base planes and their surface characteristics were respectively analyzed. The surface fluctuation data were perfectly reproduced by a Gaussian distribution function. The standard deviations of the distribution demonstrate the fluctuation range and the distribution of the entire surface fluctuation profiles. As an effective parameter to evaluate the hydraulic grinding process and the spray behaviors, the standard deviation was considered feasible for the analysis of the orifice internal wall surface characteristics.

Combustion performance of nozzles with multiple gas orifices in large ladles for temperature uniformity

In order to improve the baking temperature uniformity of the large ladle in steelmaking plants, the flame combustion characteristics of nozzles with different inner structures were numerically simulated with the finite volume method code Fluent. The flow field and premixed combustion reaction inside and outside the nozzle with multiple gas orifices were exhibited. Meanwhile, the influences of the gas injecting angle and the number of gas orifices on temperature, velocity, and pressure fields were studied. The results show that the flame length and width at the rear of flame temperature field reach the maximum values in the nozzle with the gas injecting angle of 20° and 4 gas orifices for the control of premixed combustion inside the nozzle, which could provide better temperature uniformity in ladles. The length of the 1273 K isothermal surface is 4.89 m, and the cross-section area at 4 m away from the outlet of the nozzle is 0.13 m2. The pressure losses of different types of nozzles range from 112.2 to 169.4 Pa and decrease with the decrement in gas injecting angle and the number of gas orifices. The ladle bottom preheating temperature is increased by 320-360 K for the optimized nozzle. The inner surface temperature differences between wall and bottom of the ladle are less than 10%. There is good baking temperature uniformity after the application of optimum structurally designed nozzles.

Computation of pressure drop for dilute gas-solid suspension across thin and thick orifices

The present work deals with the computation of the gas-solid two-phase flow pressure drop across thin and thick orifices for a vertically downward flow configuration at the higher limits of a dilute phase flow situation(0.01≤αs,in≤0.10).The Eulerian-Eulerian(two-fluid)model has been used in conjunction with the kinetic theory of granular flow with a four-way coupling approach.The validation of the solution process has been performed by comparing the computational result with the existing experimental data.It is observed that the two-phase flow pressure drop across the orifice increases with an increase in the thickness of the orifice,and the effect is more prominent at higher solid loading.The pressure drop is found to increase with an increase in the solid volume fraction.An increase in the Reynolds number or the area ratio increases the pressure drop.An increase in the size of the particles reduces the pressure drop across the orifice at both small and relatively large solid volume fractions.Finally,a two-phase multiplier has been proposed in terms of the relevant parameters,which can be useful to evaluate the gas-solid two-phase flow pressure drop across the orifice and can subsequently help to improve the system performance.

EXPERIMENTAL INVESTIGATION ON STEADY THREE DIMENSIONAL VORTEX FLOW FIELD THROUGH HORIZONTAL ORIFICES

A steady,axisymmetric vortex at an entrance of horizontal orifice,with an air- core,was formed within a special apparatus.The tangential,radial and axial velocities and their fluctuation strengths were measured in detail.The results were given in terms of formulas or curves.It shows a clear picture of vortex flow-field.

妇科经阴道自然腔道内镜手术专家共识

近年来,随着妇科单孔手术技术和腹腔镜器械的快速发展,经阴道自然腔道内镜手术(transvaginal natural orifice transluminal endoscopic surgery,vNOTES)在妇科领域得到日益广泛的应用。传统经阴道手术虽然创伤小,但具有一定的局限性,如视野限制、不能探查盆腹腔等。妇科vNOTES是在传统阴式手术基础上使用内镜系统,从而改善手术视野并拓展手术范围,使阴式手术的开展及推广逐步提升,得到妇科医生的普遍认可和推崇。在我国,该技术处于发展的早期,为规范其应用和技术推广,世界华人医师协会妇产科专业组组织专家,起草我国《妇科经阴道自然腔道内镜手术专家共识》。

中低位直肠癌微创治疗方兴未艾:NOSES的现状与展望

随着我国人群饮食习惯改变和人口老龄化,结直肠癌发病率逐年增加,其发病率和死亡率分别占我国恶性肿瘤的第4位和第5位[1]。亚洲结直肠癌中超过50%为直肠癌,而欧洲和北美为40%以下[2]。以手术为主的综合治疗是直肠癌主要治疗方法,随着微创治疗技术与理念的发展,医患双方均不止满足于肿瘤的根治性切除,对术后并发症的控制及审美要求亦越来越高。常规腹腔镜结直肠癌根治术后需在腹壁做一小切口取出标本[3]。肛门、阴道、口腔属于与体外相通的自然解剖通道,经自然腔道取标本手术(natural orifice specimen extraction surgery,NOSES)应运而生,历经十余年发展,有效降低手术并发症,增加微创效果,成为微创外科领域的“新星”。2021年中国开展NOSES的医院有373家,共开展20799例,其中结直肠肿瘤占85.8%[4]。

Robotic natural orifice specimen extraction surgery I-type F method vs conventional robotic resection for lower rectal cancer

BACKGROUND Robotic resection using the natural orifice specimen extraction surgery I-type F method(R-NOSES I-F)is a novel minimally invasive surgical strategy for the treatment of lower rectal cancer.However,the current literature on this method is limited to case reports,and further investigation into its safety and feasibility is warranted.AIM To evaluate the safety and feasibility of R-NOSES I-F for the treatment of low rectal cancer.METHODS From September 2018 to February 2022,206 patients diagnosed with low rectal cancer at First Affiliated Hospital of Nanchang University were included in this retrospective analysis.Of these patients,22 underwent R-NOSES I-F surgery(RNOSES I-F group)and 76 underwent conventional robotic-assisted low rectal cancer resection(RLRC group).Clinicopathological data of all patients were collected and analyzed.Postoperative outcomes and prognoses were compared between the two groups.Statistical analysis was performed using SPSS software.RESULTS Patients in the R-NOSES I-F group had a significantly lower visual analog score for pain on postoperative day 1(1.7±0.7 vs 2.2±0.6,P=0.003)and shorter postoperative anal venting time(2.7±0.6 vs 3.5±0.7,P<0.001)than those in the RLRC group.There were no significant differences between the two groups in terms of sex,age,body mass index,tumor size,TNM stage,operative time,intrao-perative bleeding,postoperative complications,or inflammatory response(P>0.05).Postoperative anal and urinary functions,as assessed by Wexner,low anterior resection syndrome,and International Prostate Symptom Scale scores,were similar in both groups(P>0.05).Long-term follow-up revealed no significant differences in the rates of local recurrence and distant metastasis between the two groups(P>0.05).CONCLUSION R-NOSES I-F is a safe and effective minimally invasive procedure for the treatment of lower rectal cancer.It improves pain relief,promotes gastrointestinal function recovery,and helps avoid incision-related complications.

Expanding endoscopic boundaries:Endoscopic resection of large appendiceal orifice polyps with endoscopic mucosal resection and endoscopic submucosal dissection

BACKGROUND Large appendiceal orifice polyps are traditionally treated surgically.Recently,endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)have been utilized as alternative resection techniques.AIM To evaluate the efficacy and safety of endoscopic resection techniques for the management of large appendiceal orifice polyps.METHODS This was a retrospective observational study conducted to assess the feasibility and safety of EMR and ESD for large appendiceal orifice polyps.This project was approved by the Baylor College of Medicine Institutional Review Board.Patients who underwent endoscopic resection of appendiceal orifice polyps≥1 cm from 2015 to 2022 at a tertiary referral endoscopy center in the United States were enrolled.The main outcomes of this study included en bloc resection,R0 resection,post resection adverse events,and polyp recurrence.RESULTS A total of 19 patients were identified.Most patients were female(53%)and Caucasian(95%).The mean age was 63.3±10.8 years,and the average body mass index was 28.8±6.4.The mean polyp size was 25.5±14.2 mm.74%of polyps were localized to the appendix(at or inside the appendiceal orifice)and the remaining extended into the cecum.68%of polyps occupied≥50%of the appendiceal orifice circumference.The mean procedure duration was 61.6±37.9 minutes.Polyps were resected via endoscopic mucosal resection,endoscopic submucosal dissection,and hybrid procedures in 5,6,and 8 patients,respectively.Final pathology was remarkable for tubular adenoma(n=10)[one with high grade dysplasia],sessile serrated adenoma(n=7),and tubulovillous adenoma(n=2)[two with high grade dysplasia].En bloc resection was achieved in 84%with an 88%R0 resection rate.Despite the large polyp sizes and challenging procedures,89%(n=17)of patients were discharged on the same day as their procedure.Two patients were admitted for post-procedure observation for conservative pain management.Eight patients underwent repeat colonoscopy without evidence of residual or recurrent adenomatous polyps.CONCLUSION Our study highlights how endoscopic mucosal resection,endoscopic submucosal dissection,and hybrid procedures are all appropriate techniques with minimal adverse effects,further validating the utility of endoscopic procedures in the management of large appendiceal polyps.

Effect of Dynamic Pressure Feedback Orifice on Stability of Cartridge-Type Hydraulic Pilot-Operated Relief Valve

Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole size,and pulsation frequency of the pump.However,the essential factors pertaining to the unstable vibration of relief valves remain ambiguous.In this study,the dynamic behavior of a pilot-operated relief valve is investigated using the frequency-domain method.The result suggests that the dynamic pressure feedback orifice is vital to the dynamic characteristics of the valve.A large orifice has a low flow resistance.In this case,the fluid in the main spring chamber flows freely,which is not conducive to the stability of the relief valve.However,a small orifice may create significant flow resistance,thus restricting fluid flow.In this case,the oil inside the main valve spring chamber is equivalent to a high-stiffness liquid spring.The main mass-spring vibration system has a natural frequency that differs significantly from the operating frequency of the relief valve,which is conducive to the stability of the relief valve.Good agreement is obtained between the theoretical analysis and experiments.The results indicate that designing a dynamic pressure feedback orifice of an appropriate size is beneficial to improving the stability of hydraulic pilot-operated relief valves.In addition,the dynamic pressure feedback orifice reduces the response speed of the relief valve.This study comprehensively considers the stability,rapidity,and immunity of relief valves and expands current investigations into the dynamic characteristics of relief valves from the perspective of classical control theory,thus revealing the importance of different parameters.

Novel deformable self-assembled magnetic anastomosis ring for endoscopic treatment of colonic stenosis via natural orifice

BACKGROUND Although endoscope-assisted magnetic compression anastomosis has already been reported for colonic anastomosis,there is no report on a single-approach operation using the natural orifice.AIM To design a deformable self-assembled magnetic anastomosis ring(DSAMAR)for colonic anastomosis for use in single-approach operation and evaluate its feasibility and safety through animal experiments.METHODS The animal model for colonic stenosis was prepared by partial colonic ligation in eight beagles.The magnetic compression anastomosis of their colonic stricture was performed by endoscopically assisted transanal implantation of the DSAMAR.The anastomotic specimen,obtained 2 wk after the operation,was observed by both the naked eye and a light microscope.RESULTS The DSAMAR was successfully inserted into the proximal end of colon stenosis through the anus.The DSAMAR of seven dogs was successfully transformed into rings,while that of the remaining dog was removed after the first deformation failed.The rings were successfully retransformed after optimization.All animals underwent colonic anastomosis using the DSAMAR.No device-related or procedure-related adverse events were observed.The colostomy specimens of the experimental dogs were obtained 2 wk after the operation.Both gross and histological observations showed good anastomotic healing.CONCLUSION The DSAMAR is a safe and feasible option for the treatment of colon stenosis.Its specific deformation and selfassembly capability maximize the applicability of the minimally invasive treatment.

跨入2011年中西医结合消化病学面临挑战与机遇

时光已进入2011年,现代消化病学的发展非常迅猛,形势可喜,当前西医最受关注的热点问题如下：（1）分子靶向治疗提高了肿瘤的临床疗效,延长了生存期,改善了生活质量;（2）自然腔道内镜手术（natural orifice transluminal endoscopic surgery,NOTES）的开展,打破了传统手术的固有模式,是外科理念的一种创新;