Yujiro Uchiyama

Combined use of a magnifying endoscope with a narrow band imaging system and a multibending endoscope for en bloc EMR of early stage gastric cancer.

BACKGROUND En bloc EMR is performed in Japan as a curative treatment for early stage gastric cancer. However, current methods of EMR are technically difficult and require proficiency in determining the extent of the cancer. This study assessed the feasibility of a new method to obviate these problems and to facilitate en bloc EMR. METHODS The new method uses two types of endoscopes: a magnifying endoscope with a narrow band imaging system to enhance the definition of mucosal and microcirculatory structure, and an endoscope with multibending tip deflection to maintain orientation during EMR. Forty-two consecutive cases of mucosal gastric cancer treated by EMR were reviewed retrospectively. In 12 of these patients, 12 lesions that fulfilled guideline criteria for EMR were treated by the modified, en bloc EMR method of circumferential incision and snare resection by using the two endoscopes. RESULTS The rate of complete en bloc resection with the new method of EMR was 91.7%, (11/12). There was no major complication. CONCLUSIONS The new en bloc resection method for EMR with two endoscopes described here is feasible and may be a safe and a reliable technique for curative treatment of mucosal gastric cancer.

New approach to diagnosing ampullary tumors by magnifying endoscopy combined with a narrow-band imaging system

BackgroundA newly developed narrow-band imaging (NBI) system, which uses modified optical filters, can yield clear images of microvessels and surface structure in gastric and colonic diseases. In the present study, we investigated the ability of magnifying endoscopy with NBI (MENBI) to diagnose and differentiate between benign and malignant ampullary tumors.MethodsFourteen patients, whose ampullas were noted to be significantly enlarged or protruding with conventional endoscopy, were enrolled in the study. Specimens, which were obtained by forceps biopsy, endoscopic papillectomy, and/or surgery, were retrieved for histopathological examination. The correlation between MENBI images and histopathological findings was investigated. MENBI findings were classified as I, oval-shaped villi; II, pinecone/leaf-shaped villi; or III, irregular/nonstructured. In addition, tortuous, dilated, and network-like vessels noted on the ampullary lesions with MENBI were defined as abnormal vessels.ResultsIn 6 of 14 patients, the ampullary changes were proven to be inflammatory in forceps biopsy specimens, without any evidence of malignancy after more than 1 year of follow-up. In five patients, ampullary lesions were treated by endoscopic papillectomy, and in three, by pancreatoduodenectomy. All adenomas and adenocarcinomas had type II and/or type III surface structures, and patients whose ampulla had a type I surface structure had only inflammatory or hyperplastic changes. In addition, abnormal vessels were seen only in adenocarcinomas and never in adenomas.ConclusionsMENBI has the ability and potential to predict histological characteristics of ampullary lesions.

Contrast-enhanced harmonic EUS with novel ultrasonographic contrast (Sonazoid) in the preoperative T-staging for pancreaticobiliary malignancies.

Abstract Objective. Sonazoid is a new second-generation microbubble contrast for ultrasonography. In this pilot study, the diagnostic role of contrast-enhanced harmonic imaging endoscopic ultrasonography (CH-EUS) with Sonazoid was prospectively evaluated in preoperative T-staging of pancreaticobiliary malignancies. Patients and methods. Patients with suspected pancreaticobiliary malignancies underwent CH-EUS by a single examiner. After the lesions were observed carefully with conventional harmonic imaging EUS (H-EUS), CH-EUS was performed with intravenous injection of Sonazoid. A reviewer who was blinded reviewed the recordings of H-EUS and CH-EUS and assessed the T-staging. The accuracy of H-EUS and CH-EUS for T-staging was compared to the results of surgical histopathology in patients who underwent surgery. Result. Twenty-six patients underwent surgical resection and could be included in the study. The final diagnosis were pancreatic cancer in 11, bile duct cancer in 7, gallbladder cancer in 4 and ampullary cancer in 4. The overall accuracy of H-EUS and CH-EUS for T-staging were 69.2 (18/26) and 92.4% (24/26), respectively (p < 0.05). There were disagreement in six cases between H-EUS and CH-EUS. CH-EUS staged correctly in all of these six cases, whereas H-EUS misdiagnosed the depth of invasion in one case of gallbladder cancer and one case of ampullary cancer, and invasion of portal vein in two cases of pancreatic cancer and two cases of bile duct cancer. Conclusion. The depth of invasion of biliary cancer and vascular invasion of pancreatic and biliary cancer could be demonstrated more clearly with CH-EUS compared to H-EUS. CH-EUS has the potential to improve the diagnostic accuracy of preoperative T-staging of pancreaticobiliary malignancies.

A Prospective Comparison of EUS-Guided FNA Using 25-Gauge and 22-Gauge Needles

Background and Aims. There are limited data on the differences in diagnostic yield between 25-gauge and 22-gauge EUS-FNA needles. This prospective study compared the difference in diagnostic yield between a 22-gauge and a 25-gauge needle when performing EUS-FNA. Methods. Forty-three patients with intraluminal or extraluminal mass lesions and/or lymphadenopathy were enrolled prospectively. EUS-FNA was performed for each mass lesion using both 25- and 22-gauge needles. The differences in accuracy rate, scoring of needle visibility, ease of puncture and quantity of obtained specimen were evaluated. Results. The overall accuracy of 22- and 25-gauge needle was similar at 81% and 76% respectively (N.S). Likewise the visibility scores of both needles were also similar. Overall the quantity of specimen obtained higher with the 22-gauge needle (score: 1.64 vs. P < .001). However the 25-gauge needle was significantly superior to the 22-gauge needle in terms of ease of puncture (score: 1.9 vs. 1.29, P < .001) and in the quantity of specimen in the context of pancreatic mass EUS-FNA (score: 1.8 vs. 1.58, P < .05). Conclusion. The 22-gauge and 25-gauge needles have similar overall diagnostic yield. The 25-gauge needle appeared superior in the subset of patients with hard lesions and pancreatic masses.

Color Doppler endoscopic ultrasonography in identifying groups at a high-risk of recurrence of esophageal varices after endoscopic treatment

BackgroundOur preliminary study indicated that either a high hepatofugal flow velocity in the left gastric vein (LGV) or an anterior branch dominant pattern seen under color Doppler EUS (CD-EUS) were possible contributing risk factors for variceal recurrence after endoscopic treatment. However, the sample size was too small, and in this study we aimed to validate the results of the preliminary study.MethodsSixty-eight patients treated for moderate or large esophageal varices between 2001 and 2004 at a single university hospital were enrolled in this study. CD-EUS was followed by endoscopic variceal ligation and sclerotherapy.ResultsPatients were classified into either a high-risk group, which exhibited anterior branch dominance and flow velocity of 12 cm/s or more, or a low-risk group, which included all other patients. Half of the patients in the high-risk group exhibited a recurrence within half a year, whereas it took almost 2 years for half of the patients in the other group to exhibit a recurrence (P = 0.0044). Using the Cox proportional hazard model with multivariate analysis, only the features of the high-risk group were significant in triggering recurrence of varices (hazard ratio [HR], 3.00; 95% confidence interval [CI], 1.35–6.65; P < 0.001).ConclusionsThese results suggest that patients showing anterior branch dominance and rapid hepatofugal flow velocity in the LGV on CD-EUS examination may have a high risk of an early recurrence of esophageal varices.

A pilot study of EUS-guided hot saline injection for induction of pancreatic tissue necrosis.

BACKGROUND AND STUDY AIMS Hot saline may be potentially useful for inducing necrosis of pancreatic tissue. However, the local and systemic effects are largely unknown. This pilot study aimed to evaluate the feasibility and safety of EUS-guided injection of hot saline into the pancreas in the porcine model. METHODS Boiling hot saline was injected into the tail of normal porcine pancreas under EUS guidance in six pigs via a transgastric approach. Three pigs were killed 4 hours later to study the acute effect of the hot saline injection (acute study). The remaining three pigs were killed after 7 days of clinical observation (survival study). RESULT Injection of 5 mL, 2 mL and 1 mL of hot saline produced localized necrosis (7 - 10 mm) of pancreatic tissue in the acute study. However, there was pooling of hot saline on the surface of the pancreas when 5mL was injected. On the basis of the results of the acute study, the volume of hot saline injected in the survival study was 1 mL. One milliliter of hot saline produced localized or sporadic necrosis of pancreatic tissue without any signs of pancreatitis in all three pigs in the survival study; hot saline was observed to pool on the pancreatic surface of one pig. There was no histological evidence of necrosis in the pancreatic tissue adjacent to the pooled hot saline in either the acute or the survival study. CONCLUSION EUS-guided hot saline injection of pancreatic tissue in the porcine model was technically successful and led to localized necrosis of pancreatic tissue without any sign of pancreatitis.

How do we select an endoscopic treatment for esophageal varices on the basis of hemodynamic analysis using color Doppler endoscopic ultrasonography.

We investigated the hemodynamics of the left gastric vein (LGV) and its association with variceal recurrence using color Doppler endoscopic ultrasonography (CD-EUS). The long-term results of our technique known as combined ligation and sclerotherapy showed that the risk of variceal recurrence decreased after long-term follow-up with timely repeated therapies. On the basis of the hemodynamic background of these results, it was suggested that the posterior branch of the LGV could have developed as an extravariceal shunt, whereas the anterior branch, which directly feeds varices, seemed to disappear through long-term follow-up with repeated treatments. In the study comparing CD-EUS findings between patients with and without variceal recurrence, dominance between anterior and posterior branches and the hepatofugal flow velocity of the LGV were suggested to be important factors contributing to variceal recurrence. We consider that these patients may require more intense therapy, such as the mucofibrosing technique or a technique to obliterate both the varices and their donor vessels.

Ethics in an animal study for interventional endoscopy.

The animal survival study using six dogs to determine causative factors of post−en− doscopic retrograde cholangiopancreato− graphy pancreatitis (PEP) was published in Endoscopy [1]. Although PEP is one of the most severe complications of inter− ventional endoscopy, I have serious doubts concerning the ethics of using an− imals for experimental purposes in this study and in other recent animal studies of novel endoscopic technologies. In the Buscaglia study, pancreatography was performed in the standard fashion. Re− sults of hematologic tests and necropsy after the endoscopic pancreatography were stratified by the volume of the in− jected contrast media, existence or ab− sence of papillary obstruction, with or without sphincterotomy and prophylactic pancreatic stent placement. The authors concluded that severe acinarization in− creased the risk and severity of PEP. As discussed in the article, it is well known that acinarization is a major risk factor for PEP [2± 5], and similar results have been reported from several clinical stud− ies. Additionally, several randomized con− trolled studies have demonstrated that prophylactic stent placement effectively prevents the development of PEP [6]. All the authors found in this study was what was already known. I do believe that the sacrifice of animals should be confined by a proper institutional reviewing pro− cess and approved only for medical con− tribution, and not for obtaining academic kudos.

4525 Impact of left gastric vein hemodynamics using color doppler eus in the treatment of esophageal varices.

Background: Endoscopic Variceal Ligation (EVL) is a widely used and accepted prophylactic treatment for esophageal varices (EV)Θ. EVL is often associated with early recurrence of EV, but the recurrence rate appeared to be decreased by repeated endoscopic treatment. However, the hemodynamic changes associated with recurrent EVL treatment are poorly understood. Aim: To analyze changes of hemodynamics and anatomy of LGV caused by the endoscopic treatment for EV. Methods: 48 patients (Pts) with with cirrhosis (Group A: 18 Pts had >1 year follow up after eradication of EV: Group B: 30 Pts with no previous variceal treatment) were enrolled in this study.We used curved linear array echoendoscope (Pentax FG36UX) and Processing Unit (Hitachi EUB655). We analyzed 1) The diameter and blood velocity of trunks of LGV 2) Type of branches of LGV 3) The size of paraesophageal vein (PEV) 4)The detection rate of perforating vein (PV). We classified the types of branches into three groups; Type AD (anterior branch dominant), Type B (bilateral), Type PD (posterior branch dominant).We classified the size of PEV into four grades; Grade 1 (