Hidehiko Kikuchi

Short-type single balloon enteroscope for endoscopic retrograde cholangiopancreatography with altered gastrointestinal anatomy

AIM To evaluate the effectiveness of a short-type single-balloon-enteroscope (SBE) for endoscopic retrograde cholangiopancreatography (ERCP) in patients with a reconstructed intestine. METHODS Short-type SBE was developed to perform ERCP in postoperative patients with a reconstructed intestine. Short-type SBE is a direct-viewing endoscope with the following specifications: working length, 1520 mm; total length, 1840 mm; channel diameter, 3.2 mm. In addition, short-type SBE has a water-jet channel. The study group comprised 22 patients who underwent 31 sessions of short-type SBE-assisted ERCP from June 2011 through May 2012. Reconstruction was performed by Billroth-II (B-II) gastrectomy in 6 patients (8 sessions), Roux-en-Y (R-Y) gastrectomy in 14 patients (21 sessions), and R-Y hepaticojejunostomy in 2 patients (2 sessions). We retrospectively studied the rate of reaching the blind end (papilla of Vater or choledochojejunal anastomosis), mean time required to reach the blind end, diagnostic success rate (defined as the rate of successfully imaging the bile and pancreatic ducts), therapeutic success rate (defined as the rate of successfully completing endoscopic treatment), mean procedure time, and complications. RESULTS Among the 31 sessions of ERCP, the rate of reaching the blind end was 88% in B-II gastrectomy, 91% in R-Y gastrectomy, and 100% in R-Y hepaticojejunostomy. The mean time required to reach the papilla was 18.3 min in B-II gastrectomy, 21.1 min in R-Y gastrectomy, and 32.5 min in R-Y hepaticojejunostomy. The diagnostic success rates in all patients and those with an intact papilla were respectively 86% and 86% in B-II gastrectomy, 90% and 87% in R-Y gastrectomy, and 100% in R-Y hepaticojejunostomy. The therapeutic success rates in all patients and those with an intact papilla were respectively 100% and 100% in B-II gastrectomy, 94% and 92% in R-Y gastrectomy, and 100% in R-Y hepaticojejunostomy. Because the channel diameter was 3.2 mm, stone extraction could be performed with a wire-guided basket in 12 sessions, and wire-guided intraductal ultrasonography could be performed in 8 sessions. As for complications, hyperamylasemia (defined as a rise in serum amylase levels to more than 3 times the upper limit of normal) occurred in 1 patient (7 sessions) with a B-II gastrectomy and 4 patients (19 sessions) with an R-Y gastrectomy. After ERCP in patients with an R-Y gastrectomy, 2 patients (19 sessions) had pancreatitis, 1 patient (21 sessions) had gastrointestinal perforation, and 1 patient (19 sessions) had papillary bleeding. Pancreatitis and bleeding were both mild. Gastrointestinal perforation improved after conservative treatment. CONCLUSION Short-type SBE is effective for ERCP in patients with a reconstructed intestine and allows most conventional ERCP devices to be used.

Factors affecting the diagnostic accuracy of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) for upper gastrointestinal submucosal or extraluminal solid mass lesions.

Aim:  A number of potential variables are associated with the diagnostic accuracy of endoscopic ultrasonography‐guided fine‐needle aspiration (EUS‐FNA). The aim of this study was to evaluate factors affecting the diagnostic accuracy of EUS‐FNA for upper gastrointestinal submucosal or extraluminal solid lesions.

Fine needle aspiration using forward-viewing endoscopic ultrasonography.

BACKGROUND AND STUDY AIM A prototype forward-viewing instrument has been developed for therapeutic endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA). We had the opportunity to use this forward-viewing echo endoscope and to study its clinical usefulness, mainly for diagnostic EUS-FNA. PATIENTS AND METHODS The prototype forward-viewing echo endoscope was used for 15 months between November 2006 and March 2010, in a study group comprising 47 consecutive patients. Diagnostic EUS-FNA was done in 38 patients and the diagnostic accuracy of the forward-viewing device was compared with that from an oblique-viewing echo endoscope in reference patients who were matched by disease and puncture route. Therapeutic EUS was done in nine patients (pseudocyst drainage in six; celiac ganglia neurolysis, biliary drainage, and pancreatic duct drainage in one each). RESULTS Diagnostic EUS-FNA provided a correct diagnosis in 97.4 % (37/38 patients), which was not significantly different from the 94.7 % (36/38) in the reference patients. Lesions considered difficult to access with an oblique-viewing scope, such as those located at the fornix, or the head of the pancreas, or associated with strictures, were easily punctured, as were those located at the body or tail of the pancreas or at the porta hepatis. Treatment was successful in all nine patients who underwent therapeutic EUS procedures. None of the 47 patients had any complications. CONCLUSIONS A forward-viewing echo endoscope that allows target sites to be punctured more perpendicularly with minimal effort, can be used for diagnostic EUS-FNA and this may be advantageous, depending on the site of target lesions.

Endoscopic management of malignant biliary obstruction by means of covered metallic stents: primary stent placement vs. re-intervention

BACKGROUND AND STUDY AIMS Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Occlusion of covered metallic stents now occurs in about half of all patients with malignant biliary strictures. The removal of metallic stents followed by placement of a second stent has been attempted, but outcomes remain controversial. The aim of the current study was to evaluate the effectiveness and safety of the primary placement and secondary placement (re-intervention) of covered metallic stents and to assess the feasibility and safety of stent removal. PATIENTS AND METHODS The study included 186 patients with unresectable malignant biliary strictures who underwent primary stent placement between October 2001 and March 2010.  Covered biliary self-expandable metal stents (SEMSs) were removed in 39 of these patients, and 36 underwent re-intervention. The patency times, occlusion rates of the first stent and re-intervention, success rates of stent removal, and complications were investigated. RESULTS Covered SEMSs were placed in 186 patients. The median patency time of the first stent was 352 days. Stent occlusion occurred in 48.9 % of the patients and was mainly caused by debris or food residue (37 %), dislocation (19 %), and migration with hyperplasia (19 %). Stent removal was attempted in 50 patients and was successful without complication in 39 (78 %). Most of the patients in whom stent removal was unsuccessful had migration with hyperplasia. The median patency time of the second stent was 263 days. The stent patency time did not significantly differ between the first and the second stent. CONCLUSIONS Covered SEMSs could be safely removed at the time of stent occlusion. Patency rates were similar for initial stent placement and re-intervention.

Recent Advances of Biliary Stent Management

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.

NEW APPLICATION OF NARROW BAND IMAGING FOR CHOLANGIOPANCREATOSCOPY

The usefulness of narrow band imaging (NBI), which is based on the principle that the depth of light penetration depends on its wavelength, has been accepted for evaluating malignant or benign lesions in the pharynx, the upper, and lower gastrointestine. The purpose of the present paper was to investigate NBI for diagnosing biliopancreatic disease. Using NBI it has become easy to detect the surface microstructure of biliary mucosa and subjacent vascular network of the bile duct, and inflammatory scarring stenosis is visualized as a whitish scar and multiple inflammatory red spots. However, bile duct cancer was detected as a stenosis with abnormal subjacent vessels and irregular surface. Concerning pancreatic duct, NBI has clearly shown vascular network and spreading of branch‐type intraductal papillary mucinous neoplasm to the main pancreatic duct. In contrast, bile juice has been detected as red fluid and bleeding as black red. Therefore, it is important to flush the biliary system before observing with NBI.

Endoscopic ultrasonography diagnosis of subepithelial lesions

Using endoscopic ultrasonography (EUS), it is practicable to diagnose subepithelial lesions (SEL) with originating layer, echo level, and internal echo pattern etc. Lipoma, lymphangioma, and cyst have characteristic features; therefore, there is no need for endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA). Ectopic pancreas and glomus tumors, which originate from the third and fourth layers, are frequently seen in the antrum. However, ectopic pancreas located in the fundus or body is large and originates from the third and fourth layers (thickening of fourth layer). Each subepithelial lesion has characteristic findings. However, imaging differentiation of tumors originating from the fourth layer is very difficult, even if contrast echo is used. Therefore, EUS‐FNA should be done in these tumors, but the diagnostic yield for small lesions is not sufficient for clinical demands. Generally, those tumors, including small ones, should be first followed up in 6 months, then yearly follow up in cases of no significant change in size and features. When those tumors become larger than 1–2 cm, EUS‐FNA is recommended. Furthermore, unusual SEL and SEL with malignant findings such as nodular, heterogeneous, anechoic area, and ulceration indicate EUS‐FNA. Cap‐attached forward‐viewing echoendoscope is very helpful for EUS‐FNA of small SEL.

EARLY COMPLICATIONS OF ENDOSCOPIC SPHINCTEROTOMY FOR COMMON BILE DUCT STONES

Endoscopic sphincterotomy (EST) is the technique most commonly used to perform therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Recently, endoscopic papillary balloon dilatation (EPBD) has been frequently used at many hospitals instead of EST to perform procedures on the papilla. A key factor in the safe, successful outcome of therapeutic ERCP in patients with common bile duct (CBD) stones is the selection of the best‐suited procedure based on a thorough understanding of the characteristics of EST and EPBD. The most common early complications of EST are acute pancreatitis and papillary bleeding. Other complications include gastrointestinal perforation and biliary infections. However, whether EST increases the risk of acute pancreatitis remains controversial. The risk of bleeding can be decreased to some degree by the proper selection of patients, improved skills of operators, and the optimal use of peripheral devices. EST performed according to the recently developed endocut method can reduce the risk of bleeding.

CLINICAL USEFULNESS OF NEWLY DEVELOPED ELECTRONIC 360° RADIAL ENDOSCOPIC ULTRASONOGRAPHY

After the development of the mechanical radial scanning echoendoscope by Olympus Medical Systems (Tokyo, Japan), endoscopic ultrasonography (EUS) has become an indispensable examination in the clinical fields. Although mechanical radial EUS has no Doppler function because of its scanning method, Olympus Medical Systems developed a new electronic 360° radial EUS in 2003. Newly developed electronic radial EUS provides better penetration, fewer artifacts, color Doppler and power Doppler function, and tissue harmonic imaging. Its maneuverability is nearly the same as conventional mechanical radial EUS. With Doppler function it is easy to differentiate solid tumors such as pancreatic cancer, islet tumor etc., and to diagnose vascular invasion. Although there are some problems, electronic radial EUS has a promising future and it is believed that electronic radial EUS will become the standard model for the next generation of EUS equipment in imaging diagnosis.