Ming-ming Xu

Imaging of the Pancreas

The evaluation of pancreatic lesions, from solid pancreatic masses to pancreatic cysts, remains a clinical challenge. Although cross-sectional imaging remains the cornerstone of the initial evaluation of an indeterminate pancreatic lesion, advances in imaging with the advent of endoscopic ultrasound scan, elastography, contrast-enhanced endoscopic ultrasound scan, and probe-based confocal laser endomicroscopy have allowed us to visualize the pancreas in even higher resolution and diagnose premalignant and malignant lesions of the pancreas with improved accuracy. This report reviews the range of imaging tools currently available to evaluate pancreatic lesions, from solid tumors to pancreatic cysts.

Diagnosing Biliary Malignancy.

The most common malignant causes of biliary strictures are pancreatic cancer and cholangiocarcinoma. Differentiating between malignant and benign causes of biliary strictures has remained a clinical challenge. Endoscopic retrograde cholangiopancreatography (ERCP) remains the mainstay and first-line method of tissue diagnosis but has a poor diagnostic yield. This article reviews the causes of biliary strictures, the initial clinical evaluation of biliary obstruction, the diagnostic yield of ERCP-based sampling methods, the role of newer tools in the armamentarium for evaluating strictures, and ways to address the ongoing challenge of stricture evaluation in patients with primary sclerosing cholangitis.

Comparison of the diagnostic accuracy of three current guidelines for the evaluation of asymptomatic pancreatic cystic neoplasms.

Abstract Asymptomatic pancreatic cysts are a common clinical problem but only a minority of these cases progress to cancer. Our aim was to compare the accuracy to detect malignancy of the 2015 American Gastroenterological Association (AGA), the 2012 International Consensus/Fukuoka (Fukuoka guidelines [FG]), and the 2010 American College of Radiology (ACR) guidelines. We conducted a retrospective study at 3 referral centers for all patients who underwent resection for an asymptomatic pancreatic cyst between January 2008 and December 2013. We compared the accuracy of 3 guidelines in predicting high-grade dysplasia (HGD) or cancer in resected cysts. We performed logistic regression analyses to examine the association between cyst features and risk of HGD or cancer. A total of 269 patients met inclusion criteria. A total of 228 (84.8%) had a benign diagnosis or low-grade dysplasia on surgical pathology, and 41 patients (15.2%) had either HGD (n = 14) or invasive cancer (n = 27). Of the 41 patients with HGD or cancer on resection, only 3 patients would have met the AGA guidelines indications for resection based on the preoperative cyst characteristics, whereas 30/41 patients would have met the FG criteria for resection and 22/41 patients met the ACR criteria. The sensitivity, specificity, positive predictive value, negative predictive value of HGD, and/or cancer of the AGA guidelines were 7.3%, 88.2%, 10%, and 84.1%, compared to 73.2%, 45.6%, 19.5%, and 90.4% for the FG and 53.7%, 61%, 19.8%, and 88% for the ACR guidelines. In multivariable analysis, cyst size >3 cm, compared to ⩽3 cm, (odds ratio [OR] = 2.08, 95% confidence interval [CI] = 1.11, 4.2) and each year increase in age (OR = 1.07, 95% CI = 1.03, 1.11) were positively associated with risk of HGD or cancer on resection. In patients with asymptomatic branch duct-intraductal papillary mucinous neoplasms or mucinous cystic neoplasms who underwent resection, the prevalence rate of HGD or cancer was 15.2%. Using the 2015 AGA criteria for resection would have missed 92.6% of patients with HGD or cancer. The more “inclusive” FG and ACR had a higher sensitivity for HGD or cancer but lower specificity. Given the current deficiencies of these guidelines, it will be important to determine the acceptable rate of false-positives in order to prevent a single true-positive.

EUS-guided transmural gallbladder drainage: a new era has begun.

The first line management of acute cholecystitis remains surgery for patients who are good operative candidates. In high-risk operative candidates, a conservative approach of intravenous fluids and antibiotics is recommended. In those who fail conservative management, nonsurgical decompression of the gallbladder is urgently needed to prevent sepsis, perforation and death. Percutaneous gallbladder drainage (PTGBD) has been described since the 1970s [Elyaderani and Gabriele, 1979]. This can be performed with gallbladder puncture under transabdominal ultrasound or computed tomography (CT) guidance followed by placement of an indwelling 6-10 French pigtail catheter drain [Akhan et al. 2002]. This technique has been well studied with prospective data and randomized trials showing success rates upwards of 95% [Ito et al. 2004; Hatzidakis et al. 2002; Sugiyama et al. 1998]. However, PTGBD has significant complications including bleeding, bile leak, bile peritonitis, pneumothorax, bowel perforation, secondary infections and catheter dislodgement [Akhan et al. 2002]. In addition, it cannot be performed in patients with ascites or those on anticoagulants. The need for leaving an exterior drainage tube can be burdensome and uncomfortable, requiring multiple sessions [Kedia et al. 2015] and tube dislodgement occurs in 0.3–12% of patients [Ito et al. 2004, Hatzidakis et al. 2002, Kiviniemi et al. 1998]. Interestingly percutaneous drainage of the gallbladder has been increasingly used in an attempt to ‘cool off’ the gallbladder and facilitates a future resection.

Recent developments in choledochoscopy: technical and clinical advances

Peroral cholangioscopy has become an important tool in the diagnosis and treatment of a variety of biliary diseases, ranging from indeterminate biliary strictures to bile duct stones. Although the first cholangioscopy was performed in the 1970s, recent technological advances have provided us with cholangioscopes that yield high-resolution images, possess single-operator capability, and have ultrathin design to allow easier maneuverability and detailed imaging of the biliary tract. We review here the currently available devices for peroral cholangioscopy, their clinical applications, limitations, and complications.

Gastric peroral endoscopic myotomy for the treatment of refractory gastroparesis: a multicenter international experience

BACKGROUND Gastroparesis is a difficult-to-treat motility disorder with a poor response to medical therapy. Gastric peroral endoscopic pyloromyotomy (G-POEM) has been offered as a novel therapy in the treatment of refractory gastroparesis. We present a multicenter case series of our experience with G-POEM. METHODS This is an international multicenter case series of patients who underwent G-POEM for the treatment of gastroparesis. The severity of gastroparesis was assessed by delayed gastric emptying scintigraphy (GES) and an elevated gastroparesis cardinal symptoms index (GCSI). Patients then underwent G-POEM using the submucosal tunneling technique. The primary endpoint was improvement in the GCSI score and improvement in gastric emptying on repeat scintigraphy. Secondary endpoints were technical success, complication rate, procedure duration, and length of hospital stay post-procedure. RESULTS G-POEM was technically successful in all 33 patients. Symptomatic improvement was seen in 28/33 patients (85 %), with a decrease in symptom score by GCSI from 3.3 to 0.8 at follow-up (P < 0.001). The mean procedure duration was 77.6 minutes (37 - 255 minutes). Mean GES improved significantly from 222.4 minutes to 143.16 minutes (P < 0.001). Complications were minimal and included bleeding (n = 1) and an ulcer (n = 1) treated conservatively. The mean length of hospital stay post-procedure was 5.4 days (1 - 14 days). The mean follow-up duration was 11.5 months (2 - 31 months). CONCLUSION G-POEM is a technically feasible, safe, and successful procedure for the treatment of refractory gastroparesis. A further multicenter comparative study should be performed to compare this technique to laparoscopic pyloromyotomy.

One-step endoscopic ultrasound-directed gastro-gastrostomy ERCP for treatment of bile leak

A 32-year-old woman with a history of obesity who underwent Roux-en-Y gastric bypass in 2005 presented with acute cholecystitis. She underwent laparoscopic cholecystectomy, which was converted to open cholecystectomy owing to significant inflammation and adhesions. On postoperative Day 2, 300mL of bilious output was noted in the Jackson– Pratt drain, which raised concerns about a bile leak. The gastrointestinal department was consulted for endoscopic retrograde cholangiopancreatography (ERCP) and management of bile leak. Laparoscopy-assisted ERCP was felt to be high risk and difficult because of the patient’s recent open cholecystectomy with significant adhesions and inflammation. Enteroscopy-assisted ERCP was felt to have a low likelihood of success owing to a Roux limb length of > 150cm. A decision was made to pursue endoscopic ultrasound (EUS)-directed gastro-gastrostomy ERCP in one step (EDGE). EDGE involves the creation of a gastrogastrostomy fistula to gain access into the bypassed stomach. Conventional ERCP is then performed through the gastro-gastrostomy fistula after fistula maturation, which usually takes 4–6 weeks. Given the acute bile leak, EDGE was performed in one session with creation of the gastro-gastrostomy fistula tract under EUS guidance using a 15mm lumenapposing metal stent (▶Fig. 1), followed by conventional ERCP during the same session (▶Video1). ERCP showed an active bile leak (▶Fig. 2), and a fully covered metal stent was placed for biliary drainage. On postprocedure Day 1, the Jackson– Pratt drain output was no longer bilious and had decreased in volume. On postprocedure Day 2 the patient was discharged home. The patient returned for outpatient ERCP with stent removal 8 weeks later, and resolution of the bile leak was seen on the cholangiogram. After stent removal, the gastro-gastric fistula tract was closed with endoscopic suturing. EUS-guided gastro-gastrostomy ERCP has previously been described in a case series as a feasible multi-step alternative approach to balloon-assisted or laparoscopy-assisted ERCP in patients with altered anatomy from gastric bypass [1]. The technical success rate in creation of the gastro-gastrostomy fistula was 100%, and successful ERCP via the fistula tract was performed in 60% of cases. A mid-term follow-up study involving 16 patients showed improved clinical success approaching 90% [2]. The procedure was typically performed in multiple steps to allow for full maturation of the fistula. We describe here a case of the successful management of bile leak via the EDGE proceE-Videos

A wormy surprise: ERCP for intrabiliary drainage of a hydatid cyst

A 41-year-old man with a known hepatic hydatid cyst presented with several months of abdominal pain and more recent onset of jaundice. Despite repeated courses of albendazole, he reported no clinical improvement. Upon presentation, he underwent magnetic resonance cholangiopancreatography (MRCP), which revealed a multiloculated cystic structure within hepatic segments 5 and 6, measuring approximately 7 ×4.5×6.5 cm with mildly enhancing septations, and diffuse intrahepatic biliary ductal dilatation (▶Fig. 1). The patient underwent an endoscopic retrograde cholangiopancreatography (ERCP) with the initial cholangiogram showing a hilar filling defect, a common bile duct (CBD) stricture, and dilated intrahepatic ducts in segments 5 and 8 (▶Fig. 2 a). A biliary sphincterotomy was performed and the cholangioscope was advanced over the wire into the CBD, where cyst membranes were visualized mid-duct (▶Fig. 2b, ▶Video1). The CBD was then dilated with a balloon catheter and copious amounts of cyst membranes were swept from the duct (▶Fig. 2 c). The cyst membranes were collected with a Roth Net and sent to microbiology. After multiple balloon sweeps, the cholangioscope was re-inserted into the bile duct and complete clearance of cyst membranes was confirmed. A 10-Fr ×7-cm straight plastic stent was deployed in the CBD at the end of the procedure. The patient was treated with albendazole and returned a few days later for an extended right hepatectomy. His postoperative course was complicated by a bile leak that required repeat ERCP and placement of a long plastic stent to cover the defect causing the observed leak. The patient was seen at follow-up and continues to remain free of both symptoms and cysts. While surgical resection has been the mainstay in the approach to the management of hepatic hydatid cysts, ERCP can be a useful modality both to aid in the diagnosis of hepatic cyst extension into the bile ducts and for therapeutic drainage of the tapeworm cyst and membranes.

Second generation optical coherence tomography: Preliminary experience in pancreatic and biliary strictures

INTRODUCTION Evaluation of indeterminate biliary strictures remains a diagnostic challenge. Optical coherence tomography (OCT) provides in-vivo, wide-field, cross-sectional imaging at the microstructure level. We present the first preliminary data using a second-generation OCT system using volumetric laser endomicroscopy (VLE) in biliary and pancreatic duct strictures. METHODS 10 consecutive patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and OCT for indeterminate biliary or pancreatic stricture evaluation were captured in a registry. Following ductal cannulation and guidewire placement, an imaging probe was advanced into the duct and images were interpreted in-vivo. Tissue sampling with cytology brushing was performed in all cases. Demographics, procedural information, imaging data, and histologic findings were collected. RESULTS 8 had biliary strictures and 2 had pancreatic duct strictures. VLE was successfully performed in all patients (100%). Histology revealed malignancy in 3 patients (cholangiocarcinoma) and benign disease in the remaining 7 patients, including 1 with primary sclerosing cholangitis (PSC). All 3 cholangiocarcinoma patients demonstrated epithelial thickening with projections, a hyper-reflective surface with shadowing, and layering effacement (loss of visualization and haziness of inner mucosal layers). A PSC patient showed onion skin layering and hyper-reflective sub-surface structures but with preserved wall layering. Benign biliary strictures showed clearly delineated epithelial layer and clear layering in the inner mucosal layers as well as the presence of dilated hypo-reflective structures. CONCLUSION There may be characteristic VLE findings for malignant, inflammatory, and benign biliary strictures.

The evolving superiority of covered metallic stents for benign biliary strictures

We read with interest Cote et al. ’s study (1) comparing the outcomes of covered self-expanding metal stents (CSEMS) versus multiple plastic stents in the treatment of benign biliary strictures (BBS).