ENDOSONOGRAPHY‐GUIDED BILIARY DRAINAGE

Endoscopic biliary drainage (e.g. endoscopic biliary stenting [EBS]) is the treatment of choice in the management of obstructive jaundice due not only because of its lesser invasiveness and greater safety as compared with surgical drainage or percutaneous transhepatic biliary drainage (PTBD), but also due to its ability to maintain the physiological flow of bile. EBS, however, is not always possible, and surgical drainage or PTBD have been performed in such cases with difficult cannulation of the bile duct or difficult intubation of the duodenum with a duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). Recently, the role of endoscopic ultrasonography (EUS), or endosonography (ES), has expanded from simply obtaining cross‐sectional images of the gut wall or surrounding organs and tissue samples by fine‐needle aspiration cytology/biopsy to therapeutic applications. Endosonography‐guided biliary drainage (ESBD) is one of such therapeutic applications of ES and reports on this procedure are increasing. In the present article, technical aspects and the current status of ESBD are discussed. As in EBS, ESBD makes it possible to recover physiological bile flow without pain following the procedure. Therefore, ESBD is expected to soon be widely accepted as a new option for difficult cases of not only EBS but also PTBD with obstructive jaundice, and may become the treatment of choice in selected cases. Development of relevant devices will expand its indications and accelerate its spread.     

ENDOSCOPIC ULTRASOUND‐GUIDED CHOLEDOCHODUODENOSTOMY

Endoscopic biliary drainage (EBD) may be unsuccessful in some patients, because of failed biliary cannulation or tumor infiltration, limiting endoscopic access to major papilla. The alternative method of percutaneous transhepatic biliary drainage carries a risk of complications, such as bleeding, portal vein thrombus, portal vein occlusion and intra‐ or extra‐abdominal bile leakage. Recently, endoscopic ultrasonography (EUS)‐guided biliary stent placement has been described in patients with malignant biliary obstruction. Technically, EUS‐guided biliary drainage is possible via transgastric or transduodenal routes or through the small intestine using a direct access or rendezvous technique. We describe herein a technique for direct stent insertion from the duodenal bulb for the management of patients with jaundice caused by malignant obstruction of the lower extrahepatic bile duct. We think transduodenal direct access is the best treatment in patients with jaundice caused by inoperable malignant obstruction of the lower extrahepatic bile duct when EBD fails.     

RISKY ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED FINE‐NEEDLE ASPIRATION FOR ASYMPTOMATIC RETROPERITONEAL TUMORS

Paraganglioma, a sporadically occurring rare tumor should be included in the differential diagnosis of retroperitoneal tumors, such as malignant lymphomas, gastrointestinal stromal tumors, sarcoma and carcinoma of unknown primary site. A 58‐year‐old Japanese woman presented with a large retroperitoneal tumor detected by ultrasonography (US). She had no medical history of hypertension. Computed tomography showed a mass, 7 cm in diameter, located between the pancreas and the inferior vena cava. It was unclear whether the mass originated from the duodenum or the mesentery. Endoscopic ultrasonography (EUS) demonstrated a large solid paraduodenal mass. Doppler US revealed sparse vascularity in the tumor. With the differential diagnosis of retroperitoneal tumor, we carried out EUS‐FNA. At the time of the third needle puncture, transient severe hypertension was noted, with a blood pressure measurement of 269/130 mmHg. Data obtained from urine and blood examinations after EUS‐fine‐needle aspiration indicated a diagnosis of paraganglioma.     

SNARE‐OVER‐THE‐WIRE TECHNIQUE FOR SAFE EXCHANGE OF A STENT FOLLOWING ENDOSONOGRAPHY‐GUIDED BILIARY DRAINAGE

Endosonography‐guided biliary drainage (ESBD) is a new option that allows establishment of biliary drainage. Due to the diameter of the working channel of an echoendoscope, it is necessary to replace a small caliber stent with a larger one to lessen the risk of stent occlusion. However, insertion of a guidewire into the bile duct via the hole of the sinus tract following direct removal of a previously placed stent is not always possible, resulting in guidewire passage outside the fistula and bile leakage. Cannulation of the previously deployed stent, guidewire insertion into the bile duct via the cannula and the stent, and removal of the stent with the snare over the guidewire leaving the guidewire in place (the snare‐over‐the‐wire technique [SOW]) for stent exchange following ESBD was attempted. Four patients who required stent exchange following ESBD were included in the present study to evaluate the feasibility and usefulness of SOW. SOW was successful in all the cases. A new stent was also successfully deployed over the guidewire in all the cases. No complications were encountered. The snare‐over‐the‐wire technique is feasible and useful in stent exchange following ESBD for the reduction of the risk of guidewire migration.     

ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY FOR THE DIAGNOSIS OF GASTROINTESTINAL SUBMUCOSAL TUMORS

Gastrointestinal submucosal tumors (SMT) detected by barium meal study or endoscopy include various kinds of diseases and various degrees of malignancy. Endoscopic ultrasonography (EUS) can provide useful information about the differentiation of intra‐ and extra‐wall lesions, location and originating layer, presumption of their histological nature, measurement of the actual size of the lesion, and the possibility of differentiating between a benign and a malignant lesion. However, EUS alone does not reveal the complete pathology. EUS fine‐needle aspiration biopsy (EUS‐FNAB) has been reported to be a useful tissue sampling method for pancreatic mass lesions, lymph nodes swelling, posterior mediastinal masses and also gastrointestinal submucosal tumors. The EUS‐FNAB procedure is effective not only for the differential diagnosis of benignancy and malignancy, but also for the specific histopathological nature of gastrointestinal SMT using immunohistochemical staining. When used with MIB‐1 (Ki‐67) staining, and gene analysis in case of gastrointestinal stromal tumor, EUS‐FNAB may indicate its prognosis and influence decisions regarding therapeutic strategy. Thus, EUS‐FNAB is an indispensable procedure in the diagnosis of SMT.     

SUCCESSFUL ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION OF THE PELVIC LESION THROUGH THE SIGMOID COLON

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is a useful modality when the target is a lymph node located in the mediastinum, perigastric area or perirectum. Although it is difficult to carry out EUS‐FNA of the colon using an oblique view linear scope, we report two cases of successful EUS‐FNA of the lesions via the proximal sigmoid colon using a recently available new convex type EUS scope. Case 1 was a 77‐year‐old Japanese woman noted to have multiple lymph node swelling in the para‐aortic area and in the pelvis. Case 2 was a 60‐year‐old Japanese woman noted to have a large mass in the left lower abdomen. In case 1, oral EUS showed no lymph node swelling. In both cases, EUS with forward‐viewing radial echoendoscope was carried out via the anus, and multiple lymph‐node swelling or a large mass was observed near the proximal sigmoid colon. In the EUS‐FNA for these cases, we used a new convex‐type EUS scope that has an oblique view, but with a wide‐angled optical device giving a view similar to a forward one. EUS‐FNA was successfully carried out on the lesions. The pathological specimen revealed diffuse large B‐cell lymphoma in case 1 and gastrointestinal stromal tumor (GIST) in case 2.     

ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED SIMULTANEOUS INTERNAL AND EXTERNAL DRAINAGE OF INFECTED PANCREATIC PSEUDOCYSTS

The procedure for endoscopic ultrasonography (EUS)‐guided cystodrainage of pancreatic pseudocysts has been established but, at times, we encounter difficult cases because of infected pseudocysts. We report successful simultaneous internal and external drainage performed in three patients with severely infectious pancreatic pseudocysts.     

PREDICTIVE FACTORS FOR PAIN RELIEF AFTER ENDOSCOPIC ULTRASOUND‐GUIDED CELIAC PLEXUS NEUROLYSIS

Background: Celiac plexus neurolysis (CPN) is an established treatment for upper abdominal cancer pain. Recently, endoscopic ultrasound‐guided CPN (EUS‐CPN) was introduced and has enabled the performance of CPN under real‐time imaging guidance, thereby making this technique much safer and easier. However, this procedure is not always efficacious, and a limited number of patients benefit from it. It should not be recommended for patients suspected of having unfavorable outcomes. We determined the predictive factors for response to EUS‐CPN in order to enable rational selection of the therapeutic strategy. Patients and Methods: Forty‐seven consecutive patients who underwent EUS‐CPN at our institutions were eligible for this study. Absolute ethanol containing a contrast medium was injected just above the origin of the celiac trunk from the aorta under real‐time EUS guidance, and abdominal computed tomography was performed immediately after the procedure to evaluate the distribution of the injected ethanol. The efficacy in pain relief was evaluated based on the pain score at day 7 after EUS‐CPN. Results: Pain relief was obtained in 32 patients (68.1%). Multivariate analysis using a multiple logistic regression model revealed that direct invasion of the celiac plexus and distribution of ethanol only on the left side of the celiac artery were significant factors for a negative response to EUS‐CPN (odds ratio = 4.82 and 8.67, P = 0.0387 and 0.0224, respectively). Conclusion: EUS‐CPN seems to be less effective in patients with direct invasion of the celiac plexus. Ethanol should be injected on both sides of the celiac axis to obtain greater pain relief.     

ENDOSONOGRAPHY‐GUIDED BILIARY DRAINAGE IN CASES WITH DIFFICULT TRANSPAPILLARY ENDOSCOPIC BILIARY DRAINAGE

Background: Recently, reports on a new endoscopic biliary drainage technique utilizing endosonographic guidance (endosonography‐guided biliary drainage [ESBD]) have been increasing. The aim of this study was to evaluate the efficacy of ESBD in cases with difficult transpapillary endoscopic biliary drainage (EBD). Patients and Methods: Sixteen patients with obstructive jaundice who underwent ESBD because of difficult EBD between January 2007 and September 2008 were included. The technical success, complications, and clinical efficacy of ESBD were prospectively evaluated. Results: ESBD was performed via the duodenum, stomach, and esophagus in eight, six and two patients, respectively. Stent placement was successful in all cases and excellent biliary decompression was achieved in all but one patient. One patient developed localized peritonitis following guidewire migration and re‐puncture of the bile duct. In another patient, stent migration was observed one week after ESBD and re‐ESBD was carried out. Three patients underwent surgery for their primary diseases, and stent exchange was carried out in 10 patients during the course. Conclusions: ESBD is an effective treatment for obstructive jaundice that will replace percutaneous transhepatic biliary drainage in cases of difficult EBD and is a possible alternative to EBD in selected cases.     

ENDOSONOGRAPHY‐GUIDED GALLBLADDER DRAINAGE FOR ACUTE CHOLECYSTITIS FOLLOWING COVERED METAL STENT DEPLOYMENT

Endosonography‐guided biliary drainage (ESBD) is gaining acceptance as an effective treatment for obstructive jaundice. Only a few reports on the application of this technique to the gallbladder (endosonography‐guided gallbladder drainage [ESGBD]) have been published in the literature. In order to relieve acute cholecystitis which developed in a patient with unresectable malignant biliary obstruction after deployment of a covered metal stent (CMS), we applied this technique. ESGBD was carried out by using an electronic curved linear array echoendoscope. After visualization of the gallbladder and determination of the puncture route, a needle knife papillotome was advanced with electrocautery to pierce the gastric and gallbladder walls. Under the guidance of a guidewire inserted through the needle sheath into the gallbladder, a 7.2 Fr, 30 cm‐long, single pigtail plastic tube was placed to bridge the gallbladder and the stomach. No complications relevant to the procedure were encountered. ESGBD was quite effective in ameliorating the patient's acute cholecystitis and the drainage tube was removed after 10 days without sequelae. Acute cholecystitis following CMS deployment is considered to be a good indication for ESGBD.     

STANDARD IMAGING TECHNIQUES OF ENDOSCOPIC ULTRASOUND‐GUIDED FINE‐NEEDLE ASPIRATION USING A CURVED LINEAR ARRAY ECHOENDOSCOPE

Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented.     

LONG‐TERM FOLLOW UP OF PATIENTS WITH SMALL GASTROINTESTINAL STROMAL TUMORS IN THE STOMACH USING ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY

Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.     

ENDOSCOPIC NECROSECTOMY UNDER DIRECT VISION AFTER ENDOSCOPIC ULTRASOUND‐GUIDED CYSTGASTROSTOMY FOR ORGANIZED PANCREATIC NECROSIS

A 56‐year‐old man was referred for an enlarging pancreatic pseudocyst that developed after severe acute pancreatitis with gallstones. Abdominal ultrasound showed a huge cystic lesion with a large amount of solid high echoic components. Arterial phase contrast‐enhanced computed tomography scan revealed arteries across the cystic cavity. Stents were placed after endoscopic ultrasound‐guided cystgastrostomy; however, the stents were obstructed by necrotic debris, and secondary infection of the pseudocyst occurred. Therefore, the cystgastrostomy was dilated by a dilation balloon, and a forward‐viewing endoscope was inserted into the cystic cavity. Many vessels and a large amount of necrotic debris existed in the cavity. Under direct vision, all necrotic debris was safely removed using a retrieval net and forceps. One year after this procedure, there was no recurrence. Our case indicates that peripancreatic fat necrosis can cause exposure of vessels across/along the cystic cavity, and blind necrosectomy should be avoided.     

OPTIMUM NUMBER OF PERCUTANEOUS TRANSHEPATIC CHOLANGIOSCOPY‐GUIDED BIOPSIES FOR HISTOLOGIC DIAGNOSIS OF BILE DUCT CARCINOMA

Background: Percutaneous transhepatic cholangioscopy (PTCS)‐guided biopsy is used for the diagnosis of bile duct carcinoma, but the number of biopsy specimens required for diagnosis is unclear. The aim of this study was to clarify whether multiple PTCS‐guided biopsies are needed for accurate histologic diagnosis. Methods: We examined the relationships between size of the first biopsy specimen, endoscopic, cholangiographic, and pathologic features, and the presence of carcinoma in the first biopsy specimen of the primary lesion in 27 bile duct carcinomas. Results: Twenty‐six of 27 carcinomas (96%) were histologically diagnosed by PTCS‐guided biopsy; 20 (74%) were detected in the first biopsy specimen, six in the second or third biopsy specimen, and one was not detected in four biopsy specimens. Carcinomas with papillogranular mucosa by endoscopy, convex margins by cholangiography, or macroscopic types (except for sclerosing type) were detected on the first biopsy specimen more frequently than were others (15/15 vs 5/12, P <0.001; 13/13 vs 7/14, P <0.01; and 15/16 vs 5/11, P <0.01, respectively). There was no relationship between positivity for carcinoma and size of the first biopsy specimen, vascular dilatation by endoscopy, or histologic type. With the combination of preoperative endoscopy and cholangiography, main lesions with papillogranular mucosa and/or convex margins were proven to be carcinoma on the first biopsy specimen significantly more frequently than were others (17/17 vs 3/10, P <0.0001). Conclusion: If the main lesion contains neither papillogranular mucosa nor a convex margin, multiple PTCS‐guided biopsies should be performed in order to increase the sensitivity for diagnosing bile duct carcinoma.     

VALUE OF COMPUTED TOMOGRAPHY FOR EVALUATING THE INJECTION SITE IN ENDOSONOGRAPHY‐GUIDED CELIAC PLEXUS NEUROLYSIS

Endosonography‐guided celiac plexus neurolysis (EUS‐CPN) safely and effectively relieves pain associated with intra‐abdominal malignancies when the neurolytic is accurately injected. We applied contrast medium to evaluate the ethanol injection sites in patients who received EUS‐CPN due to abdominal pain caused by malignancies. We injected, under the guidance of endoscopic ultrasonography (EUS), ethanol containing 10% contrast medium into the celiac plexus of patients with intra‐abdominal pain due to malignancies. Immediately after the endoscopic therapy, patients underwent computed tomography (CT) to confirm the injection site. Images of distribution of injected solutions were classified into three groups. Injected solution dispersed in unilateral and bilateral anterocrural space was defined as ‘unilateral injection’ or ‘bilateral injection’, respectively. Injected solution located out of the anterocrural space was defined as ‘inappropriate injection’. Pre‐ and postprocedure pain was assessed using a standard analog scale. Before and 2, 4, 8, 12, and 16 weeks after the procedure, pain scores were evaluated. From April 2003 to May 2005, 13 patients were enrolled in this study. Improvement of pain score in the ‘bilateral injection’ and ‘unilateral injection’ groups was significantly superior to the change in the ‘inappropriate injection’ group. Although EUS‐CPN was effective in eight of 13 patients (61.5%), additional EUS‐CPN to the ‘inappropriate injection group’ increased the response rate to 84.6%. Injection of ethanol to the anterocrural space by EUS‐CPN produced adequate pain relief. Immediate examination by CT for confirmation of injection sites after EUS‐CPN would increase the likelihood of induction of pain relief.     

ENDOSONOGRAPHY GUIDED INJECTION THERAPY

The ability to image the gastrointestinal wall in addition to mediastinal, abdominal, retroperitoneal and pelvic organs with endosonography has permitted substantive advances in our diagnostic capabilities. Requisite to this evolution was the development of endoscopic ultrasound (EUS)‐guided fine needle aspiration (FNA) and trucut biopsy (TCB). These techniques permit pathologic confirmation of abnormalities heretofore only possible by surgical means. The next generation in this evolution is just emerging in the form of EUS‐guided fine needle injection (FNI) therapy. Standard EUS‐guided techniques for injection therapy include celiac plexus block/neurolysis, treatment of achalasia, and variceal sclerotherapy. However, this review will focus on the limited information available on EUS‐FNI of anti‐neoplastic agents for pancreatic cancer as well as EUS‐FNI of alcohol for cystic pancreatic tumors. We will also discuss potential technical hurdles that must be overcome to allow for the safe proliferation of these techniques.     

COMBINED DUODENAL STENT PLACEMENT AND ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED BILIARY DRAINAGE FOR MALIGNANT DUODENAL OBSTRUCTION WITH BILIARY STRICTURE

Patients with malignant pancreatobiliary neoplasm sometimes manifest duodenal obstruction and biliary stricture synchronously or metachronously. In this paper, we reviewed our experience with and technique for combined endoscopic duodenal stent placement and endoscopic ultrasonography (EUS)‐guided biliary drainage. Between May 2007 and September 2009, this combined technique was performed on seven patients with distal biliary strictures and duodenal obstructions. The clinical success rate of the procedure, complications, patency periods of duodenal stents and patency periods of biliary stents were retrospectively evaluated. Clinical success was achieved in all seven cases for both procedures. Complications related to EUS‐biliary drainage, namely localized peritonitis due to bile leakage, occurred in two cases. Both patients recovered without additional interventions. Occlusion of a duodenal stent was observed in one patient, but additional intervention could not be performed due to sepsis. Occlusion of both a duodenal stent and a biliary stent was also observed in one patient, and this was resolved with the insertion of an additional duodenal stent and a biliary stent exchange. In conclusion, combined duodenal stent placement and EUS‐guided biliary drainage is a therapeutic option in case of failed endoscopic retrograde cannulation of malignant strictures with a malignant duodenal obstruction.