Multi-aspect analysis of ureteral access sheath usage in retrograde intrarenal surgery: A RIRSearch group study

Objective:To evaluate the effect of ureteral access sheath(UAS)use and calibration change on stone-free rate and complications of retrograde intrarenal surgery(RIRS).Methods:Data from 568 patients undergoing RIRS for kidney or upper ureteral stones were retrospectively included.Firstly,patients were compared after 1:1 propensity score matching,according to UAS usage during RIRS(UAS used[+]87 and UAS non-used[−]87 patients).Then all UAS+patients(n=481)were subdivided according to UAS calibration:9.5-11.5 Fr,10-12 Fr,11-13 Fr,and 13-15 Fr.Primary outcomes of the study were the success and complications of RIRS.Results:Stone-free rate of UAS+patients(86.2%)was significantly higher than UAS−patients(70.1%)after propensity score matching(p=0.01).Stone-free rate increased with higher caliber UAS(9.5-11.5 Fr:66.7%;10-12 Fr:87.0%;11-13 Fr:90.6%;13-15 Fr:100%;p<0.001).Postoperative complications of UAS+patients(11.5%)were significantly lower than UAS−patients(27.6%)(p=0.01).Complications(8.7%)with 9.5-11.5 Fr UAS was lower than thicker UAS(17.2%)but was not statistically significant(p=0.09).UAS usage was an independent factor predicting stone-free status or peri-and post-operative complications(odds ratio[OR]3.654,95%confidence interval[CI]1.314-10.162;OR 4.443,95%CI 1.350-14.552;OR 4.107,95%CI 1.366-12.344,respectively).Conclusion:Use of UAS in RIRS may increase stone-free rates,which also increase with higher caliber UAS.UAS usage may reduce complications;however,complications seemingly increase with higher UAS calibration.

Percutaneous antegrade management of large proximal ureteral stones using non-papillary puncture

Objective:To evaluate the feasibility and the safety of medial non-papillary percutaneous nephrolithotomy(npPCNL)for the management of large proximal ureteral stones.Methods:We evaluated prospectively collected data of 37 patients with large proximal ureteral stones more than 1.5 cm in diameter treated by prone npPCNL.Depending on stone size,in-toto stone removal or lithotripsy using the Lithoclast®Trilogy(EMS Medical,Nyon,Switzerland)was performed.Perioperative parameters including operative time(from start of puncture to the skin suturing),stone extraction time(from the first insertion of the nephroscope to the extraction of all stone fragments),and the stone-free rate were evaluated.Results:Twenty-one males and 16 females underwent npPCNL for the management of large upper ureteral calculi.The median age and stone size of treated patients were 58(interquartile range[IQR]:51-69)years and 19.3(IQR:18.0-22.0)mm,respectively.The median operative time and stone extraction time were 25(IQR:21-29)min and 8(IQR:7-10)min,respectively.One case(2.7%)of postoperative bleeding and two cases(5.4%)of prolonged fever were managed conservatively.The stone-free rate at a 1-month follow-up was 94.6%.Conclusion:The npPCNL provides a straight route to the ureteropelvic junction and proximal ureter.Approaching from a dilated portion of the ureter under low irrigation pressure with larger diameter instruments results in effective and safe stone extraction within a few minutes.

Can early precut reduce post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with difficult bile duct cannulation?

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is associated with a variety of adverse events(AEs).One of the most important AEs is post-ERCP pancreatitis(PEP),which is most common in cases of difficult biliary cannulation.Although the precut technique has been reported as a PEP risk factor,recent studies indicate that early precut could reduce PEP,and that precut itself is not a risk factor.AIM To evaluate the safety of the precut technique,especially in terms of PEP.METHODS We conducted a retrospective study,spanning the period from November 2011 through December 2021.It included 1556 patients,aged≥20 years,who underwent their initial ERCP attempt for biliary disease with a naïve papilla at the Kawasaki University General Medical Center.We compared the PEP risk between the early precut and the delayed precut group.RESULTS The PEP incidence rate did not significantly differ between the precut and nonprecut groups.However,the PEP incidence was significantly lower in the early precut group than the delayed precut group(3.5%vs 10.5%;P=0.02).The PEP incidence in the delayed precut group without pancreatic stent insertion(17.3%)was significantly higher compared to other cases(P<0.01).CONCLUSION Our findings indicate that early precut may reduce PEP incidence.If the precut decision is delayed,a pancreatic stent should be inserted to prevent PEP.

The outcomes and safety of patients undergoing endoscopic retrograde cholangiopancreatography combining a single-use cholangioscope and a single-use duodenoscope:A multicenter retrospective international study

Background: Duodenoscope-related multidrug-resistant organism(MDRO) infections raise concerns. Disposable duodenoscopes have been recently introduced in the market and approved by regulatory agencies with the aim to reduce the risk of endoscopic retrograde cholangiopancreatography(ERCP) associated infections. The aim of this study was to evaluate the outcome of procedures performed with single-use duodenoscopes in patients with clinical indications to single-operator cholangiopancreatoscopy. Methods: This is a multicenter international, retrospective study combining all patients who underwent complex biliopancreatic interventions using the combination of a single-use duodenoscope and a single-use cholangioscope. The primary outcome was technical success defined as ERCP completion for the intended clinical indication. Secondary outcomes were procedural duration, rate of cross-over to reusable duodenoscope, operator-reported satisfaction score(1 to 10) on performance rating of the single-use duodenoscope, and adverse event(AE) rate. Results: A total of 66 patients(26, 39.4% female) were included in the study. ERCP was categorized according to ASGE ERCP grading system as 47(71.2%) grade 3 and 19(28.8%) grade 4. The technical success rate was 98.5%(65/66). Procedural duration was 64(interquartile range 15-189) min, cross-over rate to reusable duodenoscope was 1/66(1.5%). The satisfaction score of the single-use duodenoscope classified by the operators was 8.6 ± 1.3 points. Four patients(6.1%) experienced AEs not directly related to the single-use duodenoscope, namely 2 post-ERCP pancreatitis(PEP), 1 cholangitis and 1 bleeding.Conclusions: Single-use duodenoscope is effective, reliable and safe even in technically challenging procedures with a non-inferiority to reusable duodenoscope, making these devices a viable alternative to standard reusable equipment.

Splenic subcapsular hematoma following endoscopic retrograde cholangiopancreatography:A case report and review of literature

BACKGROUND Splenic injury following endoscopic retrograde cholangiopancreatography(ERCP)is a rare complication.The literature contains around 30 articles reporting various degrees of splenic injuries resulting from ERCP since the first report of splenic rupture after ERCP in 1989.CASE SUMMARY This report describes a case of splenic hematoma and stent displacement in a 69-year-old male patient who developed these conditions 7 days after undergoing ERCP and stenting.The patient had bile duct stenosis caused by a malignant tumor that was obstructing the bile duct.The diagnosis was confirmed by epigastric computed tomography and magnetic resonance cholangiopancreatography.The patient was successfully treated with percutaneous transhepatic cholangial drainage,endoscopic pyloric stent placement,and conservative management.The causes of splenic injury following ERCP are discussed.CONCLUSION ERCP has the potential to cause splenic injury.If a patient experiences symptoms such as abdominal pain,decreased blood pressure,and altered hematology after the procedure,it's important to be thoroughly investigated for postoperative bleeding and splenic injury.

Endoscopic retrograde appendicitis treatment for periappendiceal abscess: A case report

BACKGROUND Acute appendicitis is the most common abdominal emergency.At present,the main treatments for periappendiceal abscess include antibiotics and surgery.However,the complications and mortality of emergency surgery are high.The preferred therapy is conservative treatment with antibiotics first,ultrasound-guided puncture drainage or surgical treatment is followed when necessary.Endoscopic retrograde appendicitis therapy(ERAT)for acute uncomplicated appendicitis have been proved clinically effective,but it is rarely used in periap-pendiceal abscess.CASE SUMMARY We report a patient admitted to hospital because of“right lower abdominal pain for six days”.The computerized tomography(CT)of patient showed that appendicitis with fecaliths and abscess in the pelvis.The patient was treated by CT-guided puncture and drainage of abdominal abscess combined with ERAT to remove appendiceal fecaliths,irrigation and stent placement.CONCLUSION The patient did not receive surgery because of impoverished family.Abdominal pain did not recur during the follow-up period.This case confirms the value of ERAT in the treatment of periappendiceal abscess.

Impact of frailty on endoscopic retrograde cholangiopancreatography outcomes in nonagenarians:A United States national experience

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an essential therapeutic tool for biliary and pancreatic diseases.Frail and elderly patients,especially those aged≥90 years are generally considered a higher-risk population for ERCP-related complications.AIM To investigate outcomes of ERCP in the Non-agenarian population(≥90 years)concerning Frailty.METHODS This is a cohort study using the 2018-2020 National Readmission Database.Patients aged≥90 were identified who underwent ERCP,using the international classification of diseases-10 code with clinical modification.Johns Hopkins’s adjusted clinical groups frailty indicator was used to classify patients as frail and non-frail.The primary outcome was mortality,and the secondary outcomes were morbidity and the 30 d readmission rate related to ERCP.We used univariate and multivariate regression models for analysis.RESULTS A total of 9448 patients were admitted for any indications of ERCP.Frail and non-frail patients were 3445(36.46%)and 6003(63.53%)respectively.Indications for ERCP were Choledocholithiasis(74.84%),Biliary pancreatitis(9.19%),Pancreatico-biliary cancer(7.6%),Biliary stricture(4.84%),and Cholangitis(1.51%).Mortality rates were higher in frail group[adjusted odds ratio(aOR)=1.68,P=0.02].The Intra-procedural complications were insigni-ficant between the two groups which included bleeding(aOR=0.72,P=0.67),accidental punctures/lacerations(aOR=0.77,P=0.5),and mechanical ventilation rates(aOR=1.19,P=0.6).Post-ERCP complication rate was similar for bleeding(aOR=0.72,P=0.41)and post-ERCP pancreatitis(aOR=1.4,P=0.44).Frail patients had a longer length of stay(6.7 d vs 5.5 d)and higher mean total charges of hospitalization($78807 vs$71392)compared to controls(P<0.001).The 30 d all-cause readmission rates between frail and non-frail patients were similar(P=0.96).CONCLUSION There was a significantly higher mortality risk and healthcare burden amongst nonagenarian frail patients undergoing ERCP compared to non-frail.Larger studies are warranted to investigate and mitigate modifiable risk factors.

Acute cholangitis with Achromobacter xylosoxidans bacteremia after endoscopic retrograde cholangiopancreatography in hilar cholangiocarcinoma:A case report

BACKGROUND Achromobacter xylosoxidans is a Gram-negative opportunistic aerobe,usually causing nosocomial infections in immunocompromised patients with manifestations including bacteremia,pneumonia,and catheter-related infections.However,A.xylosoxidans have not yet been reported to cause biliary system infections.CASE SUMMARY A 72-year-old woman presented to the outpatient department of our hospital with a chief complaint of jaundice.Computed tomography of her abdomen revealed the presence of a mass of approximately 2.4 cm in the hilar portion of the common hepatic duct,consistent with hilar cholangiocarcinoma.We performed endoscopic retrograde cholangiopancreatography(ERCP)to decompress the obstructed left and right intrahepatic ducts(IHDs)and placed 10 cm and 11 cm biliary stents in the left and right IHDs,respectively.However,the day after the procedure,the patient developed post-ERCP cholangitis as the length of the right IHD stent was insufficient for proper bile drainage.The blood culture of the patient tested positive for A.xylosoxidans.Management measures included the replacement of the right IHD stent(11 cm)with a longer one(12 cm)and administering culturedirected antibiotic therapy,solving the cholangitis-related complications.After the cholangitis had resolved,the patient underwent surgery for hilar cholangiocarcinoma and survived for 912 d without recurrence.CONCLUSION A.xylosoxidans-induced biliary system infections are extremely rare.Clinical awareness of physicians and endoscopists is required as this rare pathogen might cause infection after endoscopic procedures.

Effect of endoscopic sphincterotomy and endoscopic papillary balloon dilation endoscopic retrograde cholangiopancreatographies on the sphincter of Oddi

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP),with its clinical ad-vantages of less trauma and faster recovery,has become the primary treatment for choledocholithiasis.AIM To investigate the effects of different ERCP procedures on the sphincter of Oddi.METHODS The clinical data of 91 patients who underwent ERCP at Yixing Hospital of Traditional Chinese Medicine between February 2018 and February 2021 were analyzed retrospectively.The patients were divided into endoscopic sphinc-terotomy(EST,n=24)and endoscopic papillary balloon dilation(EPBD,n=67)groups.The duration of operation,pancreatic development,pancreatic sphinc-terotomy,intubation difficulties,stone recurrence,and incidence of reflux cho-langitis and cholecystitis were statistically analyzed in patients with a history of choledocholithiasis,pancreatitis,and Oddi sphincter dysfunction in the EST and EPBD groups.RESULTS Differences in hypertension,diabetes,increased bilirubin,small diameter of the common bile duct,or ampullary diverticulum between the two groups were not significant.Statistically significant differences were observed between the two groups concerning sex and age(<60 years).Patients with a history of choledocholithiasis,pancreatitis,and Oddi sphincter dysfunction were higher in the EST group than in the EPBD group.The number of cases of pancreatic development,pancreatic duct sphincterotomy,and difficult intubation were higher in the EST group than in the EPBD group.The number of Oddi’s sphincter manometries,ERCP surgical outcomes,and guidewires entering the pancreatic duct several times in EST group were lower than those in the EPBD group.The numbers of stone recurrences,reflux cholangitis,and cholecystitis were higher in the EST group than in the EPBD group.CONCLUSION In summary,common bile duct stones,pancreatitis history,and multiple guided wire introductions into the pancreatic duct are independent risk factors for EST and EPBD.Based on this evidence,this study can provide actionable insights for clinicians and researchers.

Recognition and management of stent malposition in the portal vein during endoscopic retrograde cholangiopancreatography:A case report

BACKGROUND Portal vein injury is an uncommon complication of endoscopic retrograde cholangiopancreatography(ERCP),for which stent malpositioning in the portal vein is very rare and can lead to fatal events.We report a case of biliary stent migration to the portal vein and a novel method for its safe removal under the guidance of portal angiography.Moreover,we reviewed the literature and summarized reports on the identification and management of this condition.CASE SUMMARY A 59-year-old woman with pancreatic cancer presented with abdominal pain and a high fever 20 days after the placement of two plastic biliary stents under the guidance of ERCP.Blood cultures and laboratory tests revealed sepsis,which was treated with antibiotics.A contrast-enhanced computed tomography scan revealed that one of the biliary stents in the main portal vein was malpositioned.To safely remove the stent,portal angiography was performed to visualize the portal vein and to allow the management of any bleeding.The two stents were removed without obvious bleeding,and an uncovered self-expanding metal stent was placed in the common bile duct for drainage.The patient had an uneventful 6-month follow-up period,except for self-resolving portal vein thrombosis.CONCLUSION The combination of endoscopic and angiographic techniques allowed uneventful management of stent malposition in the portal vein.

Endoscopic ultrasound-guided biliary drainage after failed endoscopic retrograde cholangiopancreatography: The road is open for almighty biliopancreatic endoscopists!

Commentary on the article written and published by Peng et al,investigating the role of endoscopic ultrasound(EUS)-guided biliary drainage for palliation of malignant biliary obstruction after failed endoscopic retrograde cholangiopan-creatography(ERCP).For 40 years endoscopic biliary drainage was synonymous with ERCP,and EUS was used mainly for diagnostic purposes.The advent of therapeutic EUS has revolutionized the field,especially with the development of a novel device such as electrocautery-enhanced lumen-apposing metal stents.Complete biliopancreatic endoscopists with both skills in ERCP and in interven-tional EUS,would be ideally suited to ensure patients the best drainage technique according to each individual situation.

Endoscopic dilation of complete oesophageal obstructionswith a combined antegrade-retrograde rendezvoustechnique

AIM: To investigate the combined antegraderetrograde endoscopic rendezvous technique for complete oesophageal obstruction and the swallowing outcome.METHODS: This single-centre case series includes consecutive patients who were unable to swallow due to complete oesophageal obstruction and underwent combined antegrade-retrograde endoscopic dilation(CARD) within the last 10 years. The patients' demographic characteristics, clinical parameters, endoscopic therapy, adverse events, and outcomes were obtained retrospectively. Technical success was defined as effective restoration of oesophageal patency. Swallowing success was defined as either percutaneous endoscopic gastrostomy(PEG)-tube independency and/or relevant improvement of oral food intake, as assessed by the functional oral intake scale(FOIS)(≥ level 3).RESULTS: The cohort consisted of six patients [five males; mean age 71 years(range, 54-74)]. All but one patient had undergone radiotherapy for head and neck or oesophageal cancer. Technical success was achieved in five out of six patients. After discharge, repeated dilations were performed in all five patients. During follow-up(median 27 mo, range, 2-115), three patients remained PEG-tube dependent. Three of four patients achieved relevant improvement of swallowing(two patients: FOIS 6, one patient: FOIS 7). One patient developed mediastinal emphysema following CARD, without a need for surgery.CONCLUSION: The CARD technique is safe and a viable alternative to high-risk blind antegrade dilation in patients with complete proximal oesophageal obstruction. Although only half of the patients remained PEG-tube independent, the majority improved their ability to swallow.

Intravascular ultrasound-guided “extended” reverse controlled antegrade and retrograde subintimal tracking technique using a cutting balloon for recanalizing chronic coronary total occlusion with a side branch

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) represents the most technically challenging procedure in contemporary interventional cardiology.[1] Blunt lesions and presence of proximal side branch are considered to be strong predictors of reduced technical success.[ 2,3] For such lesions, the antegrade approach may not be feasible or desirable, and the retrograde approach can be used as the initial crossing strategy. However, when treating the blunt CTO with a large side branch proximal to the occlusion, the side branch might be occluded after stent implantation if the retrograde guidewire passed the occluded segment through the subintimal space and re-entered into the true lumen at the opposite side of the side branch.[4] We reported a useful method to solve the above issue which utilizes intravascular ultrasound (IVUS) to guide “extended” reverse controlled antegrade and retrograde subintimal tracking (CART) technique with a cutting balloon.

Risk factors of recurrent choledocholithiasis following therapeutic endoscopic retrograde cholangiopancreatography

Background:The risk factors for the recurrent choledocholithiasis after endoscopic retrograde cholangiopancreatography(ERCP)have not been well studied.The aim of this study was to explore the risk factors of recurrent choledocholithiasis.Methods:We carried out a retrospective analysis of data collected between January 1,2010 and January 1,2020.Univariate analysis and multivariate analysis were used to explore the independent risk factors of recurrent choledocholithiasis following therapeutic ERCP.Results:In total,598 patients were eventually selected for analysis,299 patients in the recurrent choledocholithiasis group and 299 patients in the control group.The overall rate of recurrent choledocholithiasis was 6.91%.Multivariate analysis showed that diabetes[odds ratio(OR)=3.677,95%confidence interval(CI):1.875-7.209;P<0.001],fatty liver(OR=4.741,95%CI:1.205-18.653;P=0.026),liver cirrhosis(OR=3.900,95%CI:1.358-11.201;P=0.011),history of smoking(OR=3.773,95%CI:2.060-6.908;P<0.001),intrahepatic bile duct stone(OR=4.208,95%CI:2.220-7.976;P<0.001),biliary stent(OR=2.996,95%CI:1.870-4.800;P<0.001),and endoscopic papillary balloon dilation(EPBD)(OR=3.009,95%CI:1.921-4.715;P<0.001)were independent risk factors of recurrent choledocholithiasis.However,history of drinking(OR=0.183,95%CI:0.099-0.337;P<0.001),eating light food frequently(OR=0.511,95%CI:0.343-0.760;P=0.001),and antibiotic use before ERCP(OR=0.315,95%CI:0.200-0.497;P<0.001)were independent protective factors of recurrent choledocholithiasis.Conclusions:Patients with the abovementioned risk factors are more likely to have recurrent CBD stones.Patients who eat light food frequently and have a history of drinking are less likely to present with recurrent CBD calculi.

External use of mirabilite to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis in children:A multicenter randomized controlled trial

BACKGROUND Acute pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography(ERCP).Currently,there is no suitable treatment for post-ERCP pancreatitis(PEP)prophylaxis.Few studies have prospectively evaluated interventions to prevent PEP in children.AIM To assess the efficacy and safety of the external use of mirabilite to prevent PEP in children.METHODS This multicenter,randomized controlled clinical trial enrolled patients with chronic pancreatitis scheduled for ERCP according to eligibility criteria.Patients were randomly divided into the external use of mirabilite group(external use of mirabilite in a bag on the projected abdominal area within 30 min before ERCP)and blank group.The primary outcome was the incidence of PEP.The secondary outcomes included the severity of PEP,abdominal pain scores,levels of serum inflammatory markers[tumor necrosis factor-alpha(TNF-α)and serum interleukin-10(IL-10)],and intestinal barrier function markers[diamine oxidase(DAO),D-lactic acid,and endotoxin].Additionally,the side effects of topical mirabilite were investigated.RESULTSA total of 234 patients were enrolled,including 117 in the external use of mirabilite group and theother 117 in the blank group.The pre-procedure and procedure-related factors were notsignificantly different between the two groups.The incidence of PEP in the external use ofmirabilite group was significantly lower than that in the blank group(7.7%vs 26.5%,P<0.001).The severity of PEP decreased in the mirabilite group(P=0.023).At 24 h after the procedure,thevisual analog scale score in the external use of mirabilite group was lower than that in the blankgroup(P=0.001).Compared with those in the blank group,the TNF-αexpressions weresignificantly lower and the IL-10 expressions were significantly higher at 24 h after the procedurein the external use of mirabilite group(P=0.032 and P=0.011,respectively).There were nosignificant differences in serum DAO,D-lactic acid,and endotoxin levels before and after ERCPbetween the two groups.No adverse effects of mirabilite were observed.CONCLUSIONExternal use of mirabilite reduced the PEP occurrence.It significantly alleviated post-proceduralpain and reduced inflammatory response.Our results favor the external use of mirabilite toprevent PEP in children.

Treatment of portosystemic shunt-borne hepatic encephalopathy in a 97-year-old woman using balloon-occluded retrograde transvenous obliteration:A case report

BACKGROUND Hyperammonemia and hepatic encephalopathy are common in patients with portosystemic shunts.Surgical shunt occlusion has been standard treatment,although recently the less invasive balloon-occluded retrograde transvenous obliteration(B-RTO)has gained increasing attention.Thus far,there have been no reports on the treatment of portosystemic shunts with B-RTO in patients aged over 90 years.In this study,we present a case of hepatic encephalopathy caused by shunting of the left common iliac and inferior mesenteric veins,successfully treated with B-RTO.CASE SUMMARY A 97-year-old woman with no history of liver disease was admitted to our hospital because of disturbance of consciousness.She had no jaundice,spider angioma,palmar erythema,hepatosplenomegaly,or asterixis.Her blood tests showed hyperammonemia,and abdominal contrast-enhanced computed tomography revealed a portosystemic shunt running between the left common iliac vein and the inferior mesenteric vein.She was diagnosed with hepatic encephalopathy secondary to a portosystemic shunt.The patient did not improve with conservative treatment:Lactulose,rifaximin,and a low-protein diet.B-RTO was performed,which resulted in shunt closure and improvement in hyperammonemia and disturbance of consciousness.Moreover,there was no abdominal pain or elevated levels of liver enzymes due to complications.The patient was discharged without further consciousness disturbance.CONCLUSION Portosystemic shunt-borne hepatic encephalopathy must be considered in the differential diagnosis for consciousness disturbance,including abnormal behavior and speech.

A rabies virus-based toolkit for efficient retrograde labeling and monosynaptic tracing

Analyzing the structure and function of the brain's neural network is critical for identifying the working principles of the brain and the mechanisms of brain diseases.Recombinant rabies viral vectors allow for the retrograde labeling of projection neurons and cell type-specific trans-monosynaptic tracing,making these vectors powerful candidates for the dissection of synaptic inputs.Although several attenuated rabies viral vectors have been developed,their application in studies of functional networks is hindered by the long preparation cycle and low yield of these vectors.To overcome these limitations,we developed an improved production system for the rapid rescue and preparation of a high-titer CVS-N2c-ΔG virus.Our results showed that the new CVS-N2c-ΔG-based toolkit performed remarkably:(1)N2cG-coated CVS-N2c-ΔG allowed for efficient retrograde access to projection neurons that were unaddressed by rAAV9-Retro,and the efficiency was six times higher than that of rAAV9-Retro;(2)the trans-monosynaptic efficiency of oG-mediated CVS-N2c-ΔG was 2–3 times higher than that of oG-mediated SAD-B19-ΔG;(3)CVS-N2c-ΔG could delivery modified genes for neural activity monitoring,and the time window during which this was maintained was 3 weeks;and(4)CVS-N2c-ΔG could express sufficient recombinases for efficient transgene recombination.These findings demonstrate that new CVS-N2c-ΔG-based toolkit may serve as a versatile tool for structural and functional studies of neural circuits.

Endoscopic retrograde cholangiopancreatography management for choledochocele in a young female

To the Editor:Choledochocele,also known as type III choledochal cysts in the classification by Todani et al.[1],is a congenital abnormality of the biliary system.It is characterized by a cystic dilation of intramural segment of the distal common bile duct(CBD)protruding into the descending duodenum.Choledochocele makes up about 0.5%−4%of choledochal cysts[1,2].Compared with other subtypes,the incidence of choledochocele is extremely low and it frequently presents in adults at a relatively older age,with an average age of 51 years[3].The diagnosis and treatment are challenging.Here,we present a case of a young female patient with this rare disease entity,who recovered after effective endoscopic retrograde cholangiopancreatography(ERCP)management.

Real-time continuous image guidance for endoscopic retrograde cholangiopancreatography based on 3D/2D registration and respiratory compensation

BACKGROUND It has been confirmed that three-dimensional(3D)imaging allows easier identification of bile duct anatomy and intraoperative guidance of endoscopic retrograde cholangiopancreatography(ERCP),which reduces the radiation dose and procedure time with improved safety.However,current 3D biliary imaging does not have good real-time fusion with intraoperative imaging,a process meant to overcome the influence of intraoperative respiratory motion and guide navigation.The present study explored the feasibility of real-time continuous image-guided ERCP.AIM To explore the feasibility of real-time continuous image-guided ERCP.METHODS We selected 23D-printed abdominal biliary tract models with different structures to simulate different patients.The ERCP environment was simulated for the biliary phantom experiment to create a navigation system,which was further tested in patients.In addition,based on the estimation of the patient’s respiratory motion,preoperative 3D biliary imaging from computed tomography of 18 patients with cholelithiasis was registered and fused in real-time with 2D fluoroscopic sequence generated by the C-arm unit during ERCP.RESULTS Continuous image-guided ERCP was applied in the biliary phantom with a registration error of 0.46 mm±0.13 mm and a tracking error of 0.64 mm±0.24mm.After estimating the respiratory motion,3D/2D registration accurately transformed preoperative 3D biliary images to each image in the X-ray image sequence in real-time in 18 patients,with an average fusion rate of 88%.CONCLUSION Continuous image-guided ERCP may be an effective approach to assist the operator and reduce the use of X-ray and contrast agents.

Retrograde intrarenal surgery for lower pole stones utilizing stone displacement technique yields excellent results

Objective:To evaluate the long-term stone-free rate(SFR)of retrograde intrarenal surgery(RIRS)in the treatment of lower pole renal calculi using only basket relocation and identify independent predictors of stone-free status.Methods:All consecutive patients undergoing RIRS lower pole renal calculi at a single highvolume tertiary center were analyzed retrospectively.Lower pole stones were relocated to the upper pole,where laser lithotripsy was performed.All patients were followed up in the clinic following the surgery and yearly thereafter.The stone-free status was assessed with a combination of an abdominal ultrasound and abdominal X-ray,or an abdominal non-contrast computed tomography if the stones were known to be radiolucent.Results:A total of 480 consecutive patients who underwent RIRS for treatment of lower pole renal calculi,between January 2012 and December 2018,were analyzed from a prospectively maintained database of 3000 ureteroscopies.With a median follow-up time of 18.6 months,the mean SFR was 94.8%.The procedures were unsuccessful in 26(5.4%)patients due to unreachable stones.The median stone size of the unreachable stones was 12 mm(range 10e30 mm).Multivariable logistic regression analysis revealed two predictors of SFR for lower pole stones:a small cumulative stone burden(odds ratio[OR]:0.903,95%confidence interval[CI]:0.867e0.941,p<0.0001)and preoperative ureteral stent insertion(OR:0.515,95%CI:0.318e0.835,pZ0.007).Conclusion:The long-term SFR of RIRS for the treatment of lower pole stones with basket displacement with appropriate patient selection is high.