A method for reducing thermal injury during the ureteroscopic holmium laser lithotripsy

Objective:Many studies have demonstrated the heat effect from the holmium laser lithotripsy can cause persistent thermal injury to the ureter.The purpose of this study was to elucidate the use of a modified ureteral catheter with appropriate firing and irrigation to reduce the thermal injury to the“ureter”during the ureteroscopic holmium laser lithotripsy in vitro.Methods:An in vitro lithotripsy was performed using a modified catheter(5 Fr)as the entrance for the irrigation and the holmium laser fiber while using the remaining space in the ureteroscopic channel as an outlet.Different laser power settings(10 W,20 W,and 30 W)with various firing times(3 s,5 s,and 10 s)and rates of irrigation(15 mL/min,20 mL/min,and 30 mL/min)were applied in the experiment.Temperature changes in the“ureter”were recorded with a thermometer during and after the lithotripsy.Results:During the lithotripsy,the local highest mean temperature was 60.3℃ and the lowest mean temperature was 26.7℃.When the power was set to 10 w,the temperature was maintained below 43℃ regardless of laser firing time or irrigation flow.Regardless of the power or firing time selected,the temperature was below 43℃ at the rate of 30 mL/min.There was a significant difference in temperature decrease when continuous 3 s drainage after continuous firing(3 s,5 s,or 10 s)compared to with not drainage(p<0.05)except for two conditions of 0.5 J×20 Hz,30 mL/min,firing 5 s,and 1.0 J×10 Hz,30 mL/min,firing 5 s.Conclusion:Our modified catheter with timely drainage reducing hot irrigation may significantly reduce the local thermal injury effect,especially along with the special interrupted-time firing setting during the simulated holmium laser procedure.

Thulium fiber laser lithotripsy:Is it living up to the hype?

Objective:The holmium:yttrium-aluminium-garnet laser(Ho:YAG)has been the gold standard for laser lithotripsy over the last three decades.After demonstrating good in vitro efficacy,the thulium fiber laser(TFL)has been recently released in the market and the initial clinical results are encouraging.This article aims to review the main technology differences between the Ho:YAG laser and the TFL,discuss the initial clinical results with the TFL as well as the optimal settings for TFL lithotripsy.Methods:We reviewed the literature focusing on the technological aspects of the Ho:YAG laser and TFL as well as the results of in vitro and in vivo studies comparing both technologies.Results:In vitro studies show a technical superiority of TFL compared to the Ho:YAG laser and encouraging results have been demonstrated in clinical practice.However,as TFL is a new technology,limited studies are currently available,and the optimal settings for lithotripsy are not yet established.Conclusion:TFL has the potential to be an alternative to the Ho:YAG laser,but more reports are still needed to determine the optimal laser for lithotripsy of urinary tract stones when considering all parameters including effectiveness,safety,and costs.

Type I Mirizzi syndrome treated by electrohydraulic lithotripsy under the direct view of SpyGlass:A case report

BACKGROUND Mirizzi syndrome is an uncommon clinical complication for which the available treatment options mainly include open surgery,laparoscopic surgery,endoscopic retrograde cholangiopancreatography(ERCP),electrohydraulic lithotripsy,and laser lithotripsy.Here,a patient diagnosed with type I Mirizzi syndrome was treated with electrohydraulic lithotripsy under SpyGlass direct visualization,which may provide a reference to explore new treatments for Mirizzi syndrome.CASE SUMMARY This paper describes a middle-aged female patient with suspected choledocholithiasis who complained for over 1 mo of intermittent abdominal pain,dark yellow urine,jaundice,and was proposed to undergo ERCP lithotomy.Mirizzi syndrome was found during the operation and confirmed by SpyGlass.Electrohydraulic lithotripsy was performed under the direct vision of SpyGlass.After the lithotripsy,the stones were extracted using the stone extraction basket and balloon.After the operation,the patient developed transient hyperamylasemia.Through a series of symptomatic treatments(such as fasting,fluids and antiinflammation medications),the symptoms of the patient improved.Finally,laparoscopic cholecystectomy or open cholecystectomy was performed after a half-year post-operatively.CONCLUSION Direct visualization-guided laser or electrohydraulic lithotripsy with SpyGlass is feasible and minimally invasive for type I Mirizzi syndrome without apparent unsafe outcomes.

Use of intravascular lithotripsy in non-coronary artery lesions

BACKGROUND Intravascular lithotripsy(IVL)is a novel technique increasingly used for plaque modification and endovascular revascularization in patients with severe calcification and peripheral artery disease.However,much of the available literature on IVL is focused on its use in coronary arteries,with relatively limited data on non-coronary artery use.AIM To analyze the safety and efficacy of current IVL use in non-coronary artery lesions,as reported in case reports and case series.METHODS We searched EMBASE,PubMed,and Reference Citation Analysis databases for case reports and case series on IVL use in peripheral artery disease.We then extracted variables of interest and calculated the mean and proportions of these variables.RESULTS We included 60 patients from 33 case reports/case series.Ninety-eight percent of the cases had IVL usage in only one blood vessel,while four had the IVL used in two vessels(2.0%),resulting in 64 Lesions treated with IVL.The mean age of the patients was 73.7(SD 10.9).IVL was successfully used in severe iliofemoral artery stenosis(51.6%),severe innominate,subclavian,and carotid artery stenosis(26.7%combined),and severe mesenteric vessel stenosis(9.4%).Additionally,IVL was successfully used in severe renal(7.8%)and aortic artery(4.7%)stenosis.There were complications in 12%of the cases,with dissection being the commonest.CONCLUSION IVL has successfully used in plaque modification and endovascular revascularization in severely calcified and challenging lesions in the iliofemoral,carotid,subclavian,aorta,renal,and mesenteric vessels.The most severe but transient complications were with IVL use in the aortic arch and neck arteries.

The use of an artificial neural network in the evaluation of the extracorporeal shockwave lithotripsy as a treatment of choice for urinary lithiasis

Objective:Artificial neural networks(ANNs)are widely applied in medicine,since they substantially increase the sensitivity and specificity of the diagnosis,classification,and the prognosis of a medical condition.In this study,we constructed an ANN to evaluate several parameters of extracorporeal shockwave lithotripsy(ESWL),such as the outcome and safety of the procedure.Methods:Patients with urinary lithiasis suitable for ESWL treatment were enrolled.An ANN was designed using MATLAB.Medical data were collected from all patients and 12 nodes were used as inputs.Conventional statistical analysis was also performed.Results:Finally,716 patients were included in our study.Univariate analysis revealed that diabetes and hydronephrosis were positively correlated with ESWL complications.Regarding efficacy,univariate analysis revealed that stone location,stone size,the number and density of shockwaves delivered,and the presence of a stent in the ureter were independent factors of the ESWL outcome.This was further confirmed when adjusted for sex and age in a multivariate analysis.The performance of the ANN at the end of the training state reached 98.72%.The four basic ratios(sensitivity,specificity,positive predictive value,and negative predictive value)were calculated for both training and evaluation data sets.The performance of the ANN at the end of the evaluation state was 81.43%.Conclusion:Our ANN achieved high score in predicting the outcome and the side effects of the ESWL treatment for urinary stones.

Gallbladder biliary lithotripsy:A new rationale applied to old treatment

Pure endoscopic treatment of combined cholelithiasis and choledocholithiasis is possible due to the chance to use together both endoscopic retrograde cholangiopancreatography(ERCP)and endoscopic ultrasound(EUS)approaches.This endotherapy permits to treat biliary stones in the main bile duct by standard ERCP and gallbladder stones by EUS-guided cholecystoduodenostomy eventually associated to intracorporeal lithotripsy to achieve optimal results.

Bouveret syndrome masquerading as a gastric mass-unmasked with endoscopic luminal laser lithotripsy:A case report

BACKGROUND Bouveret syndrome,also known as gallstone ileus,is a rare form of gastric outlet obstruction accounting for 1%-3%of cases.This condition is most often reported in females.The diagnosis can be challenging and is often missed due to atypical presentations,which occasionally mimic gastric outlet obstruction symptoms such as nausea,vomiting,loss of appetite and hematemesis.The symptoms vary with stone size.Larger stones are managed with a surgical approach,but this carries increased morbidity and mortality.Over the past decade,the endoscopic approach has emerged as an alternative mode of treatment,but it is generally unsuccessful in the management of larger-sized stones.A literature review revealed cases of successful endoscopic treatment requiring multiple sessions for stone sizes measuring up to about 4.5 cm.Here we present a unique case of an elderly patient with Bouveret syndrome with a 5 cm stone mimicking a gastric mass and causing gastric outlet obstruction,who was successfully managed in a single session using a complete endoscopic approach with laser lithotripsy.CASE SUMMARY An 85-year-old female patient presented with 1-month history of intermittent abdominal pain,vomiting,decreased appetite and weight loss.An abdominal computed tomography showed a 4.5 cm×4.7 cm partially calcified mass at the gastric pylorus causing gastric outlet obstruction.Endoscopy showed an ulcerated fistulous opening and a large 5 cm impacted gallstone in the duodenal bulb.Endoscopic nets and baskets were used in an attempt to remove the stone,but this approach was unsuccessful.Given her advanced age,poor physical condition and underlying comorbidities,she was deemed to be high-risk for surgery.Thus,a minimally invasive approach using endoscopic laser lithotripsy was attempted and successfully treated the stone.Post-procedure,the patient experienced complete resolution of her symptoms with no complications and was able to tolerate her diet.She was subsequently discharged home at 48 h,with an uneventful recovery.CONCLUSION In our paper we describe Bouveret syndrome and highlight its management with a novel endoscopic approach of laser lithotripsy in addition to various other endoscopic approaches available to date and its success rates.

Do available data support the widespread adoption of pancreatoscopy guided-lithotripsy?

Peroral pancreatoscopy(POPS)is a demanding endoscopic procedure that can be used to perform intracanal lithotripsy in obstructing pancreatic stones but the experience is limited.Most stones can be removed successfully by endoscopic retrograde cholangio-pancreatography but patients with large stones require advanced therapeutic approaches,such as extracorporeal shock wave lithotripsy(alone or followed by endoscopic retrograde cholangio-pancreatography),currently the mainstay of treatment.Unfortunately,in about 10%of cases,extracorporeal shock wave lithotripsy can fail;moreover,it is not be available in many institutions.For this subgroup of patients,POPS guided-lithotripsy can play a role and have benefits.The most consistent study concerns a retrospective multicenter analysis that enrolled few patients per center.Considering the epidemiological scenario and the scant volume of skilled endoscopists,POPS must be developed in very few high-volume referral centers with standardized pathways and capable of performing multi-modality treatment.In addition,we could reasonably assume that POPS-guided-lithotripsy should be used as rescue therapy in special situations,identifying the ideal candidate who can achieve the maximum clinical result,and carefully balancing risk/benefits ratio.

Management hepatolithiasis with operative choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy

BACKGROUND: Hepatolithiasis is very common in East Asia. It is benign in nature, but has a high recurrence rate. It is likely to lead to biliary cirrhosis and increase the risk of cholangiocarcinoma. Hence, the treatment of hepatolithiasis is difficult but vital. In this report, we present a novel approach to manage hepatolithiasis using the choledochoscopic Frequency-Doubled Double pulse Nd:YAG (FREDDY) laser lithotripsy combined with or without hepatectomy. METHODS: Between July 2009 and October 2012, 45 patients underwent choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy (laser lithotripsy group). Fortyeight patients underwent a traditional operation (traditional method group) from January 2009 to June 2009. Comparative analysis was made of demographic and clinical characteristics of the two groups. RESULTS: The final stone clearance rate of the laser lithotripsy group was 93.3%, whereas that of the traditional method group was 85.4% (P=0.22). In the laser lithotripsy group, 2 patients experienced hemobilia and 3 patients had acute cholangitis. In the traditional method group, 3 patients had intraoperative hemorrhage, 1 patient had bile leakage, 6 patients had acute cholangitis, and 1 patient died of liver failure. Moreover, the operative time in the traditional method group was significantly longer than that in the laser lithotripsy group (P=0.01). The mean hospital stay of the patients in the traditional method group was longer than that in the laser lithotripsy group (9.8 vs8.2 days, P=0.17). Recurrent intrahepatic bile duct stones were not found during the follow-up period in the two groups. CONCLUSION: Operative choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy may be an effective and safe treatment for hepatolithiasis.

Epidural anesthesia is effective for extracorporeal shock wave lithotripsy of pancreatic and biliary calculi

AIM: To evaluate the efficacy of thoracic epidural analgesia for extracorporeal shock wave lithotripsy (ESWL). METHODS: ESWL is an effective, non-invasive technique for the treatment of difficult pancreatic and large bile duct calculi. The procedure is often painful and requires large doses of analgesics. Many different anesthetic techniques have been used. Patients with either large bile duct calculi or pancreatic duct calculi which could not be extracted by routine endoscopic methods were selected. Thoracic epidural anesthesia (TEA) was routinely used in all the subjects unless contraindicated. Bupivacaine 0.25% with or without clonidine was used to block the segments D6 to D12. The dose was calculated depending on the age, height and weight of the patient. It was usually 1-2 mL per segment blocked.RESULTS: Ninety eight percent of the 1509 patients underwent ESWL under TEA. The subjects selected were within American Society of Anesthesiologists grade Ⅰ to Ⅲ. ESWL using EA permitted successful elimination of bile duct or pancreatic calculi with minimal morbidity. The procedure time was shorter in patients with TEA than in those who underwent ESWL under total intravenous anesthesia. CONCLUSION: Almost all patients undergoing ESWL with EA had effective blocks with a single catheter insertion and local anesthetic injection.

Prevention strategies for ureteral stricture following ureteroscopic lithotripsy

Ureteral stricture formation after ureteroscopic lithotripsy is a late complication that can lead to hydronephrosis and a subsequent risk of renal deterioration.The specific incidence is unknown,and the mechanism of stricture formation has not been completely explained.In this review,we summarize the current evidence regarding the incidence of this condition and discuss its pathogenesis.We then list preventive strategies to reduce the morbidity of ureteral strictures。

Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

AIM To compare the efficacy of a session of extracorporeal shock wave lithotripsy(ESWL) before endoscopic retrograde cholangiopancreatography(ERCP) vs ERCP only for problematic and large common bile duct(CBD) stones.METHODS Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups,an "ESWL + ERCP group" and an "ERCP-only" group. For ESWL + ERCP cases,ESWL was performed prior to ERCP. Clearance of the CBD,complications related to the ESWL/ERCP procedure,frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups.RESULTS There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session(74.2% vs 71.0%,P = 0.135),but a higher clearance rate within the second treatment session(84.4% vs 51.6%,P = 0.018) and total stone clearance(96.0% vs 86.0%,P = 0.029). Moreover,ESWL prior to ERCP not only reduced ERCP procedure time(43 ± 21 min vs 59 ± 28 min,P = 0.034) and the rate of mechanical lithotripsy use(20% vs 30%,P = 0.025),but also raised the clearance rate of extremely large stones(80.0% vs 40.0%,P = 0.016). Post-ERCP complications were similar for the two groups.CONCLUSION Based on the higher rate of successful stone removal and minimal complications,ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones.

Mechanical lithotripsy and/or stenting in management of difficult common bile duct stones

BACKGROUND:Mechanical lithotripsy and/or stent insertion is the alternative therapeutic approach in difficult endoscopic retrograde cholangiopancreatography (ERCP)case.This study was designed to investigate the appropriate treatment for extraction of bile duct stones in difficult cases of ERCP. METHODS:Between 2000 and 2008,744 ERCP procedures were performed in 592 patients with choledocholithiasis in our endoscopy unit.The demographic features,and clinical and laboratory findings were collected from a prospectively held database.Bile duct calculi were extracted by basket and/or balloon catheter following ERCP and sphincterotomy.Patients with retained stones were regarded as difficult cases.These patients were treated with mechanical lithotripsy and those with incomplete clearance of stones underwent stent placement. RESULTS:Two hundred and forty-five patients(41%) were male and 347(59%)were female with a mean age of 58 years(range 19-95 years).Stones were impacted in 27 patients(5%).Stone extraction was performed by basket and/or balloon catheter in 610 ERCP procedures,and lithotripsy was performed in 70 ERCP procedures.Forty- four patients underwent stent insertion,and 20 underwent stent replacement.Morbidity occurred in 39 patients (5%),with no mortality associated with the procedure.Hemorrhage occurred in 9 patients and basket impaction in 4.Mild pancreatitis and cholangitis developed in 12 and 11 patients,respectively. CONCLUSION:Difficult cases of bile duct stones can be treated successfully with lithotripsy,and a stent should be applied when the common bile duct cannot be cleared completely.

Percutaneous transhepatic cholangioscopy and lithotripsy in treating difficult biliary ductal stones: Two case reports

BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP) is preferred for managing biliary obstruction in patients with bilio-enteric anastomotic strictures(BEAS) and calculi. In patients whose duodenal anatomy is altered following upper gastrointestinal(UGI) tract surgery, ERCP is technically challenging because the biliary tree becomes difficult to access by per-oral endoscopy.Advanced endoscopic therapies like balloon-enteroscopy or rendevous-ERCP may be considered but are not always feasible. Biliary sepsis and comorbidities may also make these patients poor candidates for surgical management of their biliary obstruction.CASE SUMMARY We present two 70-year-old caucasian patients admitted as emergencies with obstructive cholangitis. Both patients had BEAS associated with calculi that were predominantly extrahepatic in Patient 1 and intrahepatic in Patient 2. Both patients were unsuitable for conventional ERCP due to surgically-altered UGl anatomy. Emergency biliary drainage was by percutaneous transhepatic cholangiography(PTC) in both cases and after 6-weeks' maturation, PTC tracts were dilated to perform percutaneous transhepatic cholangioscopy and lithotripsy(PTCSL) for duct clearance. BEAS were firstly dilated fluoroscopically,and then biliary stones were flushed into the small bowel or basket-retrieved under visualization provided by the percutaneously-inserted video cholangioscope. Lithotripsy was used to fragment impacted calculi, also under visualization by video cholangioscopy. Satisfactory duct clearance was achieved in Patient 1 after one PTCSL procedure, but Patient 2 required a further procedure to clear persisting intrahepatic calculi. Ultimately both patients had successful stone clearance confirmed by check cholangiograms.CONCLUSION PTCSL offers a pragmatic, feasible and safe method for biliary tract clearance when neither ERCP nor surgical exploration is suitable.

Successful endoscopic treatment of a large impacted gallstone in the duodenum using laser lithotripsy,Bouveret’s syndrome:A case report

BACKGROUND Bouveret´s syndrome is defined as a gastric outlet obstruction after passage of a gallstone through a fistula into the duodenum.Due to its rarity,the diagnosis of Bouveret’s syndrome is often delayed and causes a high morbidity and mortality rate.CASE SUMMARY A 93-year-old female presented with worsening pain in the right upper abdomen and vomiting.A gastroscopy revealed fluid retention caused by a massive obstructive stone in the bulbus.Endoscopic laser lithotripsy of the impacted stone was planned after multidisciplinary consultation.A Dornier Medilas H Solvo lithotripsy 350μm laser fiber(10 Hz,2 Joules)was used to disintegrate the stone into smaller pieces.The patient recovered completely.CONCLUSION A mechanical obstruction due to a gallstone that has entered the gastrointestinal tract is a complication that appears in 0.3%-0.5%of patients who have cholelithiasis.Stones larger than 2 cm can become impacted in the digestive tract,which occurs mostly in the terminal ileum.In approximately 1%-3%of cases,the stones cause obstruction in the duodenum.This phenomenon is called Bouveret’s syndrome.As this condition is mostly observed in elderly individuals with multiple comorbidities,treatment by an open surgical approach is unsuitable.Endoscopic removal is the preferred technique.The benefit of using laser lithotripsy is the precise targeting of energy onto the stone with minimal tissue injury.Endoscopic laser lithotripsy is a safe and feasible treatment option for Bouveret’s syndrome.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes

For over 35 years shock wave lithotripsy has proven to be an effective,safe and truly minimally invasive option for the treatment of nephrolithiasis.Various technical factors as well as patient selection can impact the success of the procedure.We used published work focusing on outcomes of shock wave lithotripsy,risk of complications,and strategies for improving stone fragmentation to create this review.Multiple patient and technical factors have been found to impact success of treatment.Skin to stone distance,stone density and composition,size and location of the stone within the urinary system all influence stone free rates.A slower rate with a gradual increasing voltage,precise targeting,proper coupling will improve stone fragmentation and decrease risk of complications.The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Impaction of a lithotripsy basket during endoscopic lithotomy of a common bile duct stone

The treatments for common bile duct (CBD) stones are being continually developed. Impaction of the lithotripsy basket during endoscopic removal of CBD stones was seen in 5.9% patients. We report the case of a 66-yearold woman who underwent surgery for the removal of an impacted biliary basket. She was admitted to our hospital with a complaint of right upper abdominal pain. Magnetic resonance cholangiopancreatography revealed a CBD stone (20 mm × 15 mm). We diagnosed her with choledocholithiasis and performed endoscopic retrograde cholangiopancreatography to remove the stone. However, unfortunately, the retrievable basket around the stone became impacted. An endotriptor along with forceps could not be used owing to the entrapment of the basket, and thus we performed urgent surgery. The basket containing the stone was removed through a longitudinal choledochotomy. The wires leading to the basket were cut, and the basket containing the stone was removed via the incision. A T-tube was inserted,and the choledochotomy was closed. The postoperative course was uneventful. In conclusion, if the diameter of a CBD stone is more than 20 mm, then the risk of basket impaction increases, and surgery may be necessary as the initial treatment of the CBD stone.

Endoscopic lithotripsy with peroral direct cholangioscopy using a conventional endoscope

Recently,peroral direct cholangioscopy(PDCS) using an ultra-slim endoscope has come into the spotlight.However,the working channel is too small to use various devices for lithotripsy.We report a case of endoscopic lithotripsy with PDCS using a conventional endoscope as a cholangioscope.Computed tomography scan on an 80-year-old female who was admitted with acute cholangitis showed two large stones in the bile duct.Endoscopic retrograde cholangiopancreatography was attempted first.However,mechanical lithotripsy failed because the stone was too large for the basket catheter.Finally,electric hydraulic lithotripsy with PDCS using a conventional endoscope was performed allowed the stones to be cleared completely.In conclusion,PDCS using a conventional endoscope can be an alternative solution for endoscopic lithotripsy for patients with large stones in the dilated bile duct.

Successful endoscopic treatment of colonic gallstone ileus using electrohydraulic lithotripsy

The surgical management of gallstone ileus is complex and potentially highly morbid.Initial management requires enterolithotomy and is generally followed by fistula resection at a later date.There have been reports of gallstone extraction using various endoscopic modalities to relieve the obstruction,however,to date,there has never been a published case of endoscopic stone extraction from the colon using electrohydraulic lithotripsy.In this report,we present the technique employed to successfully perform an electrohydraulic lithotripsy for removal of a large gallstone impacted in the sigmoid colon.A cavity was excavated in an obstructing 4.1 cm lamellated stone in the sigmoid colon using electrohydraulic lithotripsy.A screw stent retractor and stent extractor bored a larger lumen which allowed for guidewire advancement and stone fracture via serial pneumatic balloon dilatation.The stone fragments were removed.Electrohydraulic lithotripsy is a safe and effective method to treat colonic obstruction in the setting of gallstone ileus.

Electrohydraulic lithotripsy and rendezvous nasal endoscopic cholangiography for common bile duct stone: A case report

BACKGROUND In patients with large stones in the common bile duct(CBD),advanced treatment modalities are generally needed.Here,we present an interesting case of a huge CBD stone treated with electrohydraulic lithotripsy(EHL)by the percutaneous approach and rendezvous endoscopic retrograde cholangiography(ERC)using a nasal endoscope.CASE SUMMARY A 91-year-old woman underwent ERC for a symptomatic large CBD stone with a diameter of 50 mm.She was referred to our institution after the failure of lithotomy by ERC,and after undergoing percutaneous transhepatic biliary drainage.We attempted to fragment the stone by transhepatic cholangioscopy using EHL.However,the stones were too large and partly soft clay-like for lithotripsy.Next,we attempted lithotomy with ERC and cholangioscopy by the rendezvous technique using a nasal endoscope and achieved complete lithotomy.No complication was observed at the end of this procedure.CONCLUSION Cholangioscopy by rendezvous technique using a nasal endoscope is a feasible and safe endoscopic method for removing huge CBD stones.