Dongwook Oh

Initial experience of EUS-guided radiofrequency ablation of unresectable pancreatic cancer

BACKGROUND AND AIMS Radiofrequency ablation (RFA) has been used as a valuable treatment modality for various unresectable malignancies. EUS-guided radiofrequency ablation (EUS-RFA) of the porcine pancreas was reported to be feasible and safe in our previous study, suggesting that EUS-RFA may be applicable as an adjunct and effective alternative treatment method for unresectable pancreatic cancer. This study aimed to assess the technical feasibility and safety of EUS-RFA for unresectable pancreatic cancer. METHODS An 18-gauge endoscopic RFA electrode and a radiofrequency generator were used for the procedure. The length of the exposed tip of the RFA electrode was 10 mm. After insertion of the RFA electrode into the mass, the radiofrequency generator was activated to deliver 20 to 50 W ablation power for 10 seconds. Depending on tumor size, the procedure was repeated to sufficiently cover the tumor. RESULTS EUS-RFA was performed successfully in all 6 patients (median age 62 years, range 43-73 years). Pancreatic cancer was located in the head (n = 4) or body (n = 2) of the pancreas. The median diameter of masses was 3.8 cm (range 3cm-9cm). Four patients had stage 3 disease, and 2 patients had stage 4 disease. After the procedure, 2 patients experienced mild abdominal pain, but there were no other adverse events such as pancreatitis or bleeding. CONCLUSIONS EUS-RFA could be a technically feasible and safe option for patients with unresectable pancreatic cancer.

Endoscopic Ultrasonography-Guided Ethanol Ablation for Small Pancreatic Neuroendocrine Tumors: Results of a Pilot Study

Background/Aims Endoscopic ultrasonography (EUS)-guided ethanol ablation is gaining popularity for the treatment of focal pancreatic lesions. The aim of this study was to evaluate the safety, feasibility, and treatment response after EUS-guided ethanol injection for small pancreatic neuroendocrine tumors (p-NETs). Methods This was a retrospective analysis of a prospectively collected database including 11 consecutive patients with p-NETs who underwent EUS-guided ethanol injection. Results EUS-guided ethanol injection was successfully performed in 11 patients with 14 tumors. The final diagnosis was based on histology and clinical signs as follows: 10 non-functioning neuroendocrine tumors and four insulinomas. During follow-up (median, 370 days; range, 152 to 730 days), 10 patients underwent clinical follow-up after treatment, and one patient was excluded because of loss to follow-up. A single treatment session with an injection of 0.5 to 3.8 mL of ethanol resulted in complete responses (CRs) at the 3-month radiologic imaging for seven of 13 tumors (response rate, 53.8%). Multiple treatment sessions performed in three tumors with residual viable enhancing tissue increased the number of tumors with CRs to eight of 13 (response rate, 61.5%). Mild pancreatitis occurred in three of 11 patients. Conclusions EUS-guided ethanol injection appears to be a safe, feasible, and potentially effective method for treating small p-NETs in patients who are poor surgical candidates.

Clinical relevance of the revised Atlanta classification focusing on severity stratification system

BACKGROUND/OBJECTIVE Recognizing the limitation of the Atlanta classification for acute pancreatitis (AP), two international classifications have been recently proposed; the revised Atlanta classification and the determinant-based classification. There is an inconsistency between the two international classifications on whether infected necrosis (IN) is the major determinant of severity in AP. The aim of the current study was to validate the revised Atlanta classification and to determine the association of this new classification system with relevant clinical outcome in patients with AP. METHODS Data have been collected on 553 patients with AP admitted to a single center during the 7-year period commencing January 2006. Primary outcomes included the need for interventions, the need for intensive care unit (ICU) care, length of ICU stay, total hospital stay, and mortality. RESULTS The different grades of severity for revised Atlanta classification system were associated with statistically significant differences in terms of clinical outcomes. Patients with severe AP that had IN, compared to those without IN, were associated with worse clinical outcomes. Having stratified patients with severe AP category according to the presence or absence of IN, the mortality rate increased fourfold to 32.3% for the presence of infected necrosis. CONCLUSIONS Overall, the revised Atlanta classification seems to be valid, since it correlates well with clinical outcome. To more accurately assess clinical outcome of patients with severe AP defined by the revised Atlanta classification, however, severe AP patients with IN should be considered separately from those without IN in classification system.

Initial human experience of endoscopic ultrasound-guided photodynamic therapy with a novel photosensitizer and a flexible laser-light catheter.

BACKGROUND AND STUDY AIMS New methods for the endoscopic selective ablation of locally advanced pancreaticobiliary malignancies as a minimally invasive approach are needed. Our aim was to examine the feasibility and safety of endoscopic ultrasonography (EUS)-guided photodynamic therapy (PDT) for local tumor control in patients with locally advanced pancreaticobiliary malignancies. PATIENTS AND METHODS A chlorin e6 derivative and a flexible laser-light catheter were used to perform EUS-guided PDT in four patients with locally advanced pancreaticobiliary malignancies. RESULTS EUS-guided PDT was technically feasible in all four patients with locally advanced pancreaticobiliary malignancies (two in the caudate lobe of the liver, one in the far distal bile duct, and one in the tail of the pancreas). No treatment-related complications occurred. The median volume of necrosis produced by PDT was 4.0 cm(3) (range 0.7 - 11.3). Disease remained stable in all four patients during a median follow-up of 5 months (range 3 - 7). CONCLUSION These preliminary data suggest that EUS-guided PDT with a second-generation photosensitizer and a flexible laser probe is feasible and safe.

Endoscopic management of bile leakage after liver transplantation.

Background/Aims Endoscopic retrograde cholangiopancreatography (ERCP) can be an effective treatment for bile leakage after liver transplantation. We evaluated the efficacy of endoscopic treatment in liver transplantation in patients who developed bile leaks. Methods Forty-two patients who developed bile leaks after liver transplantation were included in the study. If a bile leak was observed on ERCP, a sphincterotomy was performed, and a nasobiliary catheter was then inserted. If a bile leak was accompanied by a bile duct stricture, either the stricture was dilated with balloons, followed by nasobiliary catheter insertion across the bile duct stricture, or endoscopic retrograde biliary drainage was performed. Results In the bile leakage alone group (22 patients), endoscopic treatment was technically successful in 19 (86.4%) and clinically successful in 17 (77.3%) cases. Among the 20 patients with bile leaks with bile duct strictures, endoscopic treatment was technically successful in 13 (65.0%) and clinically successful in 10 (50.0%) cases. Among the 42 patients who underwent ERCP, technical success was achieved in 32 (76.2%) cases and clinical success was achieved in 27 (64.3%) cases. Conclusions ERCP is an effective and safe therapeutic modality for bile leaks after liver transplantation. ERCP should be considered as an initial therapeutic modality in post-liver transplantation patients.

Clinical features of pancreatic involvement in von Hippel–Lindau disease: a retrospective study of 55 cases in a single center

Abstract Background. von Hippel–Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system and visceral organs. In this study, we describe clinical features of pancreatic involvement in VHL disease, of which there have been few reported studies to date. Methods. We reviewed medical records of 63 VHL patients, diagnosed at Asan Medical Center between January 1995 and December 2013. Demographic, genetic, and radiologic features, and the clinical course of VHL patients with pancreatic involvement were retrospectively analyzed. Results. Among the 63 VHL patients, 55 (87.4%) had VHL-associated pancreatic lesions (male: female, 31:24; median age at onset, 33 years; range, 12–67 years). These presented as single simple cysts (n = 5, 9.1%), multiple simple cysts (n = 14, 25.5%), serous cystadenoma (n = 29, 52.7%), or neuroendocrine tumors (NETs) (n = 17, 30.9%). Genetic tests were performed on 35 of the 55 patients (63.6%) and VHL gene mutations were observed in 28 of them (80%). Of the 55 patients, 11 received surgical treatment, 2 received endoscopic ultrasonography-guided ethanol ablation therapy as local treatment for NET, and 42 patients were followed regularly without intervention (20%, 3.6%, and 76.4%, respectively). Conclusion. Pancreatic involvement in VHL disease is common, with a prevalence of 87.4%. Serial screening imaging studies for the early detection of VHL-associated NET are necessary in individuals at risk of VHL disease. A large-scale epidemiological study of VHL disease is needed to examine the natural course of the disease and the prognosis for pancreatic involvement.

Optimal biliary access point and learning curve for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting:

Background: Although endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) with transmural stenting has increased for biliary decompression in patients with an inaccessible papilla, the optimal biliary access point and the learning curve of EUS-HGS have not been studied. We evaluated the optimal biliary access point and learning curve for technically successful EUS-HGS. Methods: 129 consecutive patients (male n = 81, 62.3%; malignant n = 113, 87.6%) who underwent EUS-HGS due to an inaccessible papilla were enrolled. EUS finding and procedure times according to each needle puncture attempt in EUS-HGS were prospectively measured. Learning curves of EUS-HGS were calculated for two main outcome measurements (procedure time and adverse events) by using the moving average method and cumulative sum (CUSUM) analysis, respectively. Results: A total of 174 EUS-HGS attempts were performed in 129 patients. The mean number of needle punctures was 1.35 ± 0.57. Using the logistic regression model, bile duct diameter of the puncture site ⩽ 5 mm [odds ratio (OR) 3.7, 95% confidence interval (CI): 1.71–8.1, p < 0.01] and hepatic portion length [linear distance from the mural wall to the punctured bile duct wall on EUS; mean hepatic portion length was 27 mm (range 10–47 mm)] > 3 cm (OR 5.7, 95% CI: 2.7–12, p < 0.01) were associated with low technical success. Procedure time and adverse events were shorter after 24 cases, and stabilized at 33 cases of EUS-HGS, respectively. Conclusions: Our data suggest that a bile duct diameter > 5 mm and hepatic portion length 1 cm to ⩽ 3 cm on EUS may be suitable for successful EUS-HGS. In our learning curve analysis, over 33 cases might be required to achieve the plateau phase for successful EUS-HGS.

Conversion of external percutaneous transhepatic biliary drainage to endoscopic ultrasound-guided hepaticogastrostomy after failed standard internal stenting for malignant biliary obstruction

Background and study aim Percutaneous transhepatic biliary drainage (PTBD) is a rescue procedure after a failed endoscopic retrograde cholangiopancreatography. As PTBD causes patient discomfort, conversion of the PTBD to internal biliary stenting (PTBDS) may be required; however, PTBDS is sometimes difficult because of the tight stricture. We evaluated the efficacy and safety of conversion of external PTBD to endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) after failed PTBDS. Patients and methods A total of 16 patients with malignant distal biliary obstruction who underwent conversion of external PTBD to EUS-HGS after failed PTBDS were enrolled from two institutions in Korea and Japan. Data were analyzed retrospectively. Results The technical and clinical success rates were 100 % and 81 %, respectively. Early adverse events developed in two patients: proximal stent migration (n = 1), and cholecystitis (n = 1). Stents were occluded or migrated distally in five patients. The mean duration of stent patency was 402 days. Conclusions Conversion of external PTBD to EUS-HGS may be a good rescue option after failed PTBDS.

Endoscopic ultrasound-guided fine-needle aspiration can target right liver mass

Background and Objectives: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been established as a safe and accurate method for diagnosing and staging intra-abdominal mass. However, few studies investigated its feasibility, efficacy, and safety for targeting liver mass. We evaluated the efficacy and safety of EUS-FNA in patients with liver masses including the right lobe. Patients and Methods: The technical feasibility, safety, and diagnostic yield were determined in 47 patients (30 in the left lobe and 17 in the right lobe) presenting with liver masses between September 2010 and February 2016. Results: Thirty-eight patients (80.9%) had malignancies whereas nine patients (19.1%) had benign liver masses. Technical success rate was 97.9% (46/47). EUS-FNA was diagnostic in 38 of 42 patients (90.5%). When the outcomes of EUS-FNA between right liver mass and left mass were accessed, the technical success rates were similar in both lobes (100% vs. 94.1%, P= 0.2). The median tumor size on EUS (25.5 mm, interquartile range [IQR] 13.8–30.3 vs. 28 mm, IQR 18.5–43.5, P= 0.24) and number of needle passes (3, IQR 3–4 vs. 3, IQR 3–3, P= 0.24) were not significantly different. Adequate specimen obtained was statistically higher in the left lobe (28/30, 93.3% vs. 14/17, 82.4%, P= 0.04). However, diagnostic accuracy for liver masses was not different (25/28, 89.3% vs. 13/14, 92.9%, P= 0.86). No complications developed after procedure. Conclusions: EUS-FNA can be a safe and efficient method for the diagnosis of liver mass and it is technically feasible even for those in the right lobe.

Long‐term outcomes of 6‐mm diameter fully covered self‐expandable metal stents in benign refractory pancreatic ductal stricture

Fully covered self‐expandable metal stent (FCSEMS) placement has been tried for pancreatic ductal strictures in chronic pancreatitis. However, the long‐term outcome of this procedure remains unknown. The present study aimed to investigate the procedural and long‐term outcomes of FCSEMS placement in patients with benign refractory pancreatic ductal strictures.