Intrabiliary Rupture of a Hepatic Hydatid Cyst: A Case Report.

BACKGROUND Hydatid disease is a common parasitic infection in many areas of Asia, South America, and Africa. It can affect any organ, most commonly the liver. The hydatid is often asymptomatic and the diagnosis is made when complications arise. The most common complication of this disease is opening in the bile ducts, which is a life-threatening condition causing serious acute cholangitis. We report a case of acute cholangitis caused by hydatid cyst rupture into the right bile duct. CASE REPORT A 33-year-old woman, with no medical or surgical history, presented to our Emergency Department with abdominal pain, jaundice, and fever for 3 days prior to admission. The patient was hemodynamically stable. In the examination, we noticed right upper-quadrant tenderness with guarding, icterus sclera, and negative Murphy sign. A CT scan showed a liver hydatid cyst of the 4th and 8th of segments, with intrahepatic and extrahepatic biliary duct dilation. The cyst communicated with the right hepatic bile duct via a large fistula. A diagnosis of acute cholangitis was made and she underwent conservative treatment with external drainage of the pericystic cavity through the biliary duct. The postoperative course was uncomplicated and she was discharged 15 days later. CONCLUSIONS The surgical approach to hepatic hydatid must be customized based on the specific characteristics of the cyst and associated complications. Acute hydatid cholangitis is a rare but serious complication of a hydatid cyst, which requires early diagnosis and adequate surgical management.

Management of ERCP complications.

Managing complications of ERCP poses a significant clinical challenge to endoscopists. ERCP complications can occur even after all preventive measures, which can lead to significant morbidity and even mortality. Major complications include pancreatitis, bleeding, perforation, cholangitis, and sedation-related adverse events. Early recognition of post-ERCP pancreatitis (PEP) is feasible by monitoring clinical parameters and specific cutoffs of serum amylase and lipase at 2-6 h post-ERCP. Pancreatic stenting for PEP is not recommended and can increase the incidence of infected necrosis in addition to being technically challenging. Post-sphincterotomy bleeds can be treated by diluted epinephrine with or without thermal therapy, or mechanical therapy (clips or fully covered metallic stents) failing which angiographic embolization and rarely open surgical vessel ligation may be warranted. Post-ERCP perforations can lead to significant morbidity and are usually treated with endoscopic closure of the defect, diverting bile flow, draining collections, and reducing fluid load at the site of perforation failing which surgery may be warranted. Broad-spectrum antibiotics with endoscopic or radiologic drainage of undrained segments help treat post-ERCP cholangitis. Hypoxia and hypertension are the most common sedation-related adverse events without long-term consequences except aspiration pneumonia (<0.5%). Awareness with a high index of suspicion is crucial for timely diagnosis and management of uncommon post-ERCP complications.

Urgent one-stage endoscopic treatment for choledocholithiasis related moderate to severe acute cholangitis: A propensity score-matched analysis.

BACKGROUND: During emergency endoscopic retrograde cholangiopancreatography (ERCP), the safety and feasibility of performing one-stage endoscopic treatment for patients with acute cholangitis (AC) due to choledocholithiasis are unclear. AIM: To investigate the safety and feasibility of one-stage endoscopic treatment for moderate to severe AC. METHODS: We enrolled all patients diagnosed with moderate to severe cholangitis due to common bile duct stones from January 2019 to July 2023. The outcomes were compared in this study between patients who underwent ERCP within 24 h and those who underwent ERCP 24 h later, employing a propensity score (PS) framework. Our primary outcomes were intensive care unit (ICU) admission rates, ICU length of stay, and duration of antibiotic use. RESULTS: In total, we included 254 patients and categorized them into two groups based on the time elapsed between admission and intervention: The urgent group (≤ 24 h, n = 102) and the elective group (> 24 h, n = 152). Ninety-three pairs of patients with similar characteristics were selected by PS matching. The urgent ERCP group had more ICU admissions (34.4% vs 21.5%, P = 0.05), shorter ICU stays (3 d vs 9 d, P < 0.001), fewer antibiotic use (6 d vs 9 d, P < 0.001), and shorter hospital stays (9 d vs 18.5 d, P < 0.001). There were no significant differences observed in adverse events, in-hospital mortality, recurrent cholangitis occurrence, 30-d readmission rate or 30-d mortality. CONCLUSION: Urgent one-stage ERCP provides the advantages of a shorter ICU stay, a shorter duration of antibiotic use, and a shorter hospital stay.

Comparative Risks of Post-ERCP Adverse Events in Patients with Asymptomatic and Symptomatic Choledocholithiasis: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Endoscopic retrograde cholangiopancreatography (ERCP) is the standard of care for the management of choledocholithiasis but carries risk of complications which may result in significant morbidity and mortality. While currently available guidelines endorse the use of ERCP for the management of symptomatic common bile duct stones, the need for ERCP in incidentally found asymptomatic choledocholithiasis is more controversial, and practice varies on a geographic and institutional level. This systematic review and meta-analysis is conducted to compare post-ERCP adverse events between asymptomatic and symptomatic choledocholithiasis patients. METHODS: We searched PubMed/Embase/Web of Science databases to include all studies comparing post-ERCP outcomes between asymptomatic and symptomatic choledocholithiasis patients. The primary outcome was post-ERCP pancreatitis (PEP), while secondary outcomes included post-ERCP cholangitis, bleeding, and perforation. We calculated pooled risk ratios (RR) and 95% confidence intervals (CIs) using the Mantel-Haenszel method within a random-effect model. RESULTS: Our analysis included six observational studies, totaling 2,178 choledocholithiasis patients (392 asymptomatic and 1786 symptomatic); 53% were female. Asymptomatic patients exhibited a higher risk of PEP compared with symptomatic patients (11.7% versus 4.8%; RR 2.59, 95% CI 1.56-4.31, p ≤ 0.001). No significant difference was observed in post-ERCP cholangitis, bleeding, or perforation rates between the two groups. CONCLUSIONS: Asymptomatic patients with choledocholithiasis appear to have a higher risk of PEP than symptomatic patients, while the risk of other post-ERCP adverse events is similar between the two groups. Interventional endoscopists should thoroughly discuss potential adverse events (particularly PEP) with asymptomatic patients before performing ERCP and utilize PEP-prevention measures more liberally in this subgroup of patients.

Endoscopic features of low-phospholipid-associated cholelithiasis syndrome: A retrospective cohort study.

BACKGROUND AND OBJECTIVE: LPAC (low phospholipid-associated cholelithiasis) syndrome is a rare genetic form of cholelithiasis. ERCP (endoscopic retrograde cholangiopancreatography) is often used to remove gallstones in the bile duct. No published data is available on the role of ERCP in LPAC syndrome. PATIENTS AND METHODS: In this retrospective cohort study, we included patients diagnosed with LPAC syndrome in a single tertiary referral center between 2009 and 2021. Our aim was to assess the frequency, indications, modalities, results, and complications of ERCP, as well as predictive factors for ERCP, in LPAC syndrome. Independent factors associated with ERCP occurrence were identified using a multivariable Cox regression analysis. RESULTS: ERCP was required in 31.2 % of the 269 patients included for analysis. Among patients who required ERCPs, 78.6 % had the procedure before diagnosis (i.e., starting UDCA). Most common indications were choledocholithiasis (53.6 %) and acute cholangitis (29.5 %). Post ERCP pancreatitis, perforation and bleeding rates were 7.2 %, 2.6 %, and 1.3 %, respectively. Age and history of cholelithiasis in first-degree relatives were associated with a higher risk of ERCP (Hazard-ratio [HR]=1.30 [95 %confidence-interval [CI] 1.04-1.62] and HR=1.88 [95 %CI 1.15-3.07] respectively). Female gender and UDCA intake ≥ 1 year were associated with a lower risk of ERCP (HR=0.49 [95 %CI 0.29-0.82] and HR=0.44 [95 %CI 0.22-0.90] respectively). Median follow-up was 10.8 years. CONCLUSION: One-third of patients with LPAC syndrome undergo sphincterotomy. However, most procedures are performed before diagnosis and UDCA is associated with a lower risk of endoscopic procedure. Earlier diagnosis and treatment with UDCA may further reduce the need for ERCP in patients with LPAC syndrome.

[Air embolism after biliary stent removal during endoscopic retrograde cholangiopancreatography for cholangitis after biliary reconstruction: a case report].

A 62-year-old male patient underwent pancreaticoduodenectomy with modified Child reconstruction for distal cholangiocarcinoma. After eight years, a contrast-enhanced computed tomography (CT) revealed a recurrent lesion at the biliojejunal anastomosis, and a biliary stent was placed for obstructive cholangitis in the right posterior segment of the liver. A right hepatectomy was planned for a local recurrent lesion;thus, percutaneous transhepatic portal embolization was performed on the portal vein's right branch to enlarge the left liver. However, he was referred to our department for endoscopic retrograde biliary drainage for the subsequent cholangitis and liver abscess appearance. A double-balloon enteroscope under CO2 insufflation was used to reach the bile duct-jejunal anastomosis. After removing the bile duct stent with grasping forceps, his general condition suddenly deteriorated, causing cardiopulmonary arrest. He was diagnosed with air embolism based on the findings of air in the heart, aorta, and brain on CT after the return of spontaneous circulation. Treatment for the air embolism and subsequent complications continued in the intensive care unit, but he eventually died 114 days after the onset of the air embolism due to his deteriorating general condition. Pathological autopsy revealed cholangiocarcinoma that extends from the porta hepatis to the posterior segment. Additionally, the proximity between the bile duct and vein extended by the adenocarcinoma and the fibrous obstruction of the vein were revealed, indicating the possibility of a bile duct-vein shunt.

Cholangitis with bacteremia due to Pseudomonas nitroreducens in a patient with pancreatic neuroendocrine tumors: a case report.

BACKGROUND: Pseudomonas nitroreducens is a non-fermenting, gram-negative, rod-shaped bacterium commonly inhabiting soil, particularly soil contaminated with oil brine. To our knowledge, no cases of human infection with P. nitroreducens have been previously reported. Here, we present the first documented case of cholangitis caused by P. nitroreducens in a patient with bacteremia. CASE PRESENTATION: A 46-year-old Japanese man with an advanced pancreatic neuroendocrine tumor was hospitalized with fever and chills. Four days before admission, the patient developed right upper abdominal pain. Two days later, he also experienced fever and chills. Endoscopic retrograde cholangiopancreatography was performed on the day of admission, and the patient was diagnosed as having cholangitis associated with stent dysfunction. Gram-negative rods were isolated from blood cultures, but attempts to identify the bacteria using VITEK2 and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with VITEK MS ver. 4.7.1 (bioMérieux Japan Co. Ltd., Tokyo, Japan) were unsuccessful. Finally, the organism was identified as P. nitroreducens using MALDI-TOF MS with a MALDI Biotyper (Bruker Daltonics Co., Ltd., Billerica, MA, USA) and 16 S ribosomal RNA sequencing. Despite thorough interviews with the patient, he denied any exposure to contaminated soil. The patient was treated with intravenous cefepime and oral ciprofloxacin for 16 days based on susceptibility results, achieving a good therapeutic outcome. At the outpatient follow-up on day 28, the patient was in good general condition. CONCLUSIONS: This is the first reported human case of cholangitis with bloodstream infection caused by P. nitroreducens. This report provides clinicians with novel insights into the clinical manifestations and diagnostic methods necessary for the accurate diagnosis of P. nitroreducens, along with guidance on treatment.

Recurrent cholangitis in patients with a non-stenotic hepaticojejunostomy: incidence and risk factors.

BACKGROUND: Cholangitis is a well-known complication after hepaticojejunostomy (HJ), which is mainly caused by a stenotic anastomosis. However, the rate of cholangitis in patients with a non-stenotic (i.e. patent) HJ is unknown. We aimed to evaluate the incidence and risk factors of recurrent cholangitis in patients with a non-stenotic HJ. METHODS: This single-center retrospective cohort study included all consecutive patients who had undergone hepatobiliary or pancreatic (HPB) surgery requiring HJ (2015-2022). Primary outcome was recurrent non-stenotic cholangitis, risk factors for recurrent non-stenotic cholangitis were identified using logistic regression. RESULTS: Overall, 835 patients with a HJ were included of whom 31/698 (4.4%) patients developed recurrent cholangitis with a non-stenotic HJ during a median follow-up of 34 months (IQR 22-50) and 98/796 (12.3%) patients developed a symptomatic HJ stenosis. These 31 patients experienced 205 cholangitis episodes, median 7.0 (IQR 3.8-8.8) per patient, and 71/205 (34.6%) cholangitis episodes required hospitalization. Male sex (aOR 3.17 (95% CI: 1.34-7.49)) and benign disease (aOR 2.97, 95% CI 1.40-6.33) were identified as risk factors for recurrent cholangitis in non-stenotic HJ in both univariate and multivariable analysis. CONCLUSION: This study shows that 4% of patients developed recurrent cholangitis without an underlying HJ stenosis.

[Acute cholangitis due to Candida glabrata and Klebsiella pneumoniae]. / Colangitis aguda por Candida glabrata y Klebsiella pneumoniae.

Acute cholangitis is a bile duct infection associated with bile duct obstruction. Bile culture is positive in most cases, and the most frequent etiological agent is Escherichia coli. Candida sp acute cholangitis is a rare finding, which is more common in patients with immunosuppression, use of corticosteroids, prolonged antibiotic treatment or surgical procedures of the bile duct. We present the case of a 67-year-old woman with none of the above-mentioned history who consulted for fever, abdominal pain and jaundice. MRI of the abdomen revealed a lithiasic image in the common bile duct with dilation. It required endoscopic drainage of the biliary tract. Direct microscopic examination of the bile fluid revealed gram-negative bacilli and yeast, and in the culture of bile fluid Klebsiella pneumoniae producing extended spectrum beta-lactamase (ESBL) and Candida glabrata were isolated. The patient completed the antibiotic treatment with piperacillin tazobactam and anidulafungin with good evolution. Bile duct infection by association of Gram-negative bacilli and Candida sp is a rare entity, more in patients without underlying diseases.

La colangitis aguda es una infección de la vía biliar, asociada a la obstrucción de esta. El cultivo de la bilis es positivo en la mayoría de los casos y el agente etiológico más frecuente es Escherichia coli. La colangitis aguda por Candida sp es un hallazgo poco común, que es más frecuente en pacientes con inmunocompromiso, uso de corticoides, tratamiento antibiótico prolongado o procedimientos quirúrgicos de la vía biliar. Presentamos el caso de una mujer de 67 años, que no presentaba ninguno de los antecedentes mencionados, y que consultó por fiebre, dolor abdominal e ictericia. En la resonancia magnética nuclear de abdomen se constató imagen litiásica en el colédoco con dilatación de la vía biliar. Requirió drenaje endoscópico del tracto biliar. En el examen microscópico directo del líquido biliar se evidenciaron levaduras y bacilos Gram negativos, y en el cultivo se aisló Klebsiella pneumoniae productora de betalactamasa de espectro extendido (BLEE) y Candida glabrata. La paciente completó el tratamiento antibiótico con piperacilina tazobactam y anidulafungina con buena evolución. La infección de la vía biliar por la asociación de bacilos Gram negativos y Candida sp es una entidad poco frecuente, más en pacientes sin enfermedades subyacentes.

Randomized Trial of Prophylactic Antibiotics for Endoscopic Retrograde Cholangiopancreatography in Patients With Biliary Obstruction.

INTRODUCTION: The incidence of postendoscopic retrograde cholangiopancreatography (ERCP) infections is reported to be up to 18% in patients with biliary obstruction. Antibiotic prophylaxis may reduce the risk of infectious complications after ERCP; however, the clinical value of prophylactic antibiotics in ERCP remains controversial. METHODS: We conducted a double-blind, placebo-controlled, randomized trial to investigate whether the use of prophylactic antibiotics would reduce infectious complications after ERCP in patients with biliary obstruction. We randomly assigned patients in a 1:1 ratio to receive either a single dose of 1 g intravenous cefoxitin or normal saline as a placebo 30 minutes before undergoing ERCP. The primary outcome was the incidence of infectious complications after ERCP. RESULTS: We enrolled 378 patients, and 189 patients were assigned to each group. The risk of infectious complications after ERCP was 2.8% (5 of 176 patients) in the antibiotic prophylaxis group and 9.8% (17 of 173 patients) in the placebo group (risk ratio, 0.29; 95% confidence interval [CI], 0.11-0.74, P = 0.0073). The incidence rates of bacteremia were 2.3% (4 of 176 patients) and 6.4% (11 of 173 patients), respectively (risk ratio, 0.36; 95% CI, 0.12-1.04; P = 0.0599). The incidence rate of cholangitis was 1.7% (3 of 176 patients) in the antibiotic prophylaxis group and 6.4% (11 of 173 patients) in the placebo group (risk ratio, 0.27; 95% CI, 0.08-0.87; P = 0.0267). DISCUSSION: Antibiotic prophylaxis before ERCP in patients with biliary obstruction resulted in a significantly lower risk of infectious complications, especially cholangitis, than placebo ( ClinicalTrials.gov trial number NCT02958059).

Conventional vs Short Duration of Antibiotics in Patients With Moderate or Severe Cholangitis: Noninferiority Randomized Trial.

INTRODUCTION: Successful biliary drainage and antibiotics are the mainstays of therapy in management of patients with acute cholangitis. However, the duration of antibiotic therapy after successful biliary drainage has not been prospectively evaluated. We conducted a single-center, randomized, noninferiority trial to compare short duration of antibiotic therapy with conventional duration of antibiotic therapy in patients with moderate or severe cholangitis. METHODS: Consecutive patients were screened for the inclusion criteria and randomized into either conventional duration (CD) group (8 days) or short duration (SD) group (4 days) of antibiotic therapy. The primary outcome was clinical cure (absence of recurrence of cholangitis at day 30 and >50% reduction of bilirubin at day 15). Secondary outcomes were total days of antibiotic therapy and hospitalization within 30 days, antibiotic-related adverse events, and all-cause mortality at day 30. RESULTS: The study included 120 patients (the mean age was 55.85 ± 13.52 years, and 50% were male patients). Of them, 51.7% patients had malignant etiology and 76.7% patients had moderate cholangitis. Clinical cure was seen in 79.66% (95% confidence interval, 67.58%-88.12%) patients in the CD group and 77.97% (95% confidence interval, 65.74%-86.78%) patients in the SD group ( P = 0.822). On multivariate analysis, malignant etiology and hypotension at presentation were associated with lower clinical cure. Total duration of antibiotics required postintervention was lower in the SD group (8.58 ± 1.92 and 4.75 ± 2.32 days; P < 0.001). Duration of hospitalization and mortality were similar in both the groups. DISCUSSION: Short duration of antibiotics is noninferior to conventional duration in patients with moderate-to-severe cholangitis in terms of clinical cure, recurrence of cholangitis, and overall mortality.

Long-term outcomes of choledochoduodenostomy for choledocholithiasis: increased incidence of postoperative cholangitis after total or distal gastrectomy.

PURPOSE: Choledochoduodenostomy (CDD) is performed to treat choledocholithiasis (CDL) cases where endoscopic stone removal is difficult. Recognizing CDD characteristics is important for CDL treatment planning. METHODS: A total of 116 patients, including 33 patients ≥ 80 years old (29 with previous total gastrectomy, 19 with previous distal gastrectomy, 20 with built-up stones, 19 with periampullary diverticulum, 10 with confluence stones, 8 with repetitive recurrent stones, 4 with hard stones, 3 with endoscopic retrograde cholangiography [ERC] not available due to lack of cooperation, 2 with a history of pancreatitis post-ERC, and 2 in whom ERC could not be performed due to a disturbed anatomy) underwent CDD for CDL. Postoperative complications and long-term outcomes were evaluated. RESULTS: The in-hospital mortality rate was 0%. The morbidity (grade ≥ IIIA according to the Clavien-Dindo classification) rates in the elderly (≥ 80 years old) and non-elderly (51-79 years old) patients were 3.0% (1/33) and 2.4% (2/83), respectively (p = 0.85). Long-term complications included cholangitis in eight (7%) patients, of which three cases were repetitive and seven had an operative history of total or distal gastrectomy. The incidence of postoperative cholangitis after total or distal gastrectomy was 15% (7/48), which was significantly higher than that involving other causes (1.5%, 1/68; p < 0.01). Two patients with cholangitis after total gastrectomy experienced early recurrence of lithiasis at 2 and 9 months after surgery. CONCLUSIONS: CDD is safe, even in elderly patients. However, a history of total gastrectomy or distal gastrectomy may increase the incidence of postoperative cholangitis.

Preoperative endoscopic biliary drainage by metal versus plastic stents for resectable perihilar cholangiocarcinoma.

BACKGROUND AND AIMS: Adequate preoperative biliary drainage (PBD) is recommended in most patients with resectable perihilar cholangiocarcinoma (pCCA). Most expert centers use endoscopic plastic stents rather than self-expandable metal stents (SEMSs). In the palliative setting, however, use of SEMSs has shown longer patency and superior survival. The aim of this retrospective study was to compare stent dysfunction of SEMSs versus plastic stents for PBD in resectable pCCA patients. METHODS: In this multicenter international retrospective cohort study, patients with potentially resectable pCCAs who underwent initial endoscopic PBD from 2010 to 2020 were included. Stent failure was a composite end point of cholangitis or reintervention due to adverse events or insufficient PBD. Other adverse events, surgical outcomes, and survival were recorded. Propensity score matching (PSM) was performed on several baseline characteristics. RESULTS: A total of 474 patients had successful stent placement, of whom 61 received SEMSs and 413 plastic stents. PSM (1:1) resulted in 2 groups of 59 patients each. Stent failure occurred significantly less in the SEMSs group (31% vs 64%; P < .001). Besides less cholangitis after SEMSs placement (15% vs 31%; P = .012), other PBD-related adverse events did not differ. The number of patients undergoing surgical resection was not significantly different (46% vs 49%; P = .71). Complete intraoperative SEMSs removal was successful and without adverse events in all patients. CONCLUSIONS: Stent failure was lower in patients with SEMSs as PBD compared with plastic stents in patients with resectable pCCA. Removal during surgery was quite feasible. Surgical outcomes were similar.

Long-term prognosis and risk factors associated with post-ERCP pneumobilia in patients with common bile duct stones.

BACKGROUND AND AIMS: Post-ERCP pneumobilia is not uncommon; however, studies focusing on the long-term prognosis of patients with post-ERCP pneumobilia are limited. This study aimed to explore long-term prognosis and risk factors associated with post-ERCP pneumobilia in patients with common bile duct stones (CBDSs). METHODS: We conducted a retrospective analysis of 1380 patients who underwent ERCP for CBDSs at our hospital from January 2010 to December 2017. Patients were selected based on inclusion and exclusion criteria and divided into pneumobilia and nonpneumobilia groups, followed by propensity score matching. The matched groups were then compared in terms of incidence rates of both single and multiple recurrences of CBDSs, acute cholangitis, and acute cholecystitis. Multivariate logistic regression analysis was used to explore risk factors associated with pneumobilia. RESULTS: After propensity matching, there was no significant difference in the rate of single recurrence of CBDSs (22.5% vs 30%; P = .446) between the pneumobilia and nonpneumobilia groups. However, the incidences of multiple recurrences of CBDSs (32.5% vs 12.5%; P = .032) and acute cholangitis without stone recurrence (32.5% vs 2.5%; P = <.001) were significantly higher in the pneumobilia group. Based on multivariate logistic regression analysis, in addition to a dilated CBD (diameter of >1 cm) (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.03-3.76; P = .043), endoscopic sphincterotomy with moderate incision (OR, 5.38; 95% CI, 1.14-25.47; P = .034) and with large incision (OR, 8.7; 95% CI, 1.83-41.46; P = .007) were identified as independent risk factors for pneumobilia after initial ERCP. CONCLUSIONS: Patients with post-ERCP pneumobilia have increased risk of multiple recurrences of CBDSs and acute cholangitis without stone recurrence. Independent risk factors for pneumobilia include peripapillary diverticulum, a dilated CBD (>1 cm), and endoscopic sphincterotomy with moderate and large incisions. A normal-sized CBD appears to serve as a secondary barrier against enterobiliary reflux, necessitating further research for confirmation.

A multi-institutional study designed by members of Tokyo Guidelines (TG) Core Meeting to elucidate the clinical characteristics and pathogenesis of acute cholangitis after bilioenteric anastomosis and biliary stent insertion with a focus on biliary obstruction: Role of transient hepatic attenuation difference (THAD) and pneumobilia in improving TG diagnostic performance.

BACKGROUND/PURPOSE: The aim of this study was to clarify the clinical characteristics of acute cholangitis (AC) after bilioenteric anastomosis and stent-related AC in a multi-institutional retrospective study, and validate the TG18 diagnostic performance for various type of cholangitis. METHODS: We retrospectively reviewed 1079 AC patients during 2020, at 16 Tokyo Guidelines 18 (TG 18) Core Meeting institutions. Of these, the post-biliary reconstruction associated AC (PBR-AC), stent-associated AC (S-AC) and common AC (C-AC) were 228, 307, and 544, respectively. The characteristics of each AC were compared, and the TG18 diagnostic performance of each was evaluated. RESULTS: The PBR-AC group showed significantly milder biliary stasis compared to the C-AC group. Using TG18 criteria, definitive diagnosis rate in the PBR-AC group was significantly lower than that in the C-AC group (59.6% vs. 79.6%, p < .001) because of significantly lower prevalence of TG 18 imaging findings and milder bile stasis. In the S-AC group, the bile stasis was also milder, but definitive-diagnostic rate was significantly higher (95.1%) compared to the C-AC group. The incidence of transient hepatic attenuation difference (THAD) and pneumobilia were more frequent in PBR-AC than that in C-AC. The definitive-diagnostic rate of PBR-AC (59.6%-78.1%) and total cohort (79.6%-85.3%) were significantly improved when newly adding these items to TG18 diagnostic imaging findings. CONCLUSIONS: The diagnostic rate of PBR-AC using TG18 is low, but adding THAD and pneumobilia to TG imaging criteria may improve TG diagnostic performance.