Hiroshi Kakutani

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.

Novel quantitative perfusion analysis with contrast-enhanced harmonic EUS for differentiation of autoimmune pancreatitis from pancreatic carcinoma

Abstract Objective. Autoimmune pancreatitis (AIP) is often misdiagnosed as pancreatic carcinoma (PC) despite recent advances in imaging tests. The aim of the study was to evaluate whether the quantitative perfusion analysis using software “Time intensity curve” with contrast-enhanced harmonic EUS (CH-EUS) facilitate the differentiation of AIP from PC. Methods. Consecutive patients with focal AIP and pancreatic carcinoma who underwent CH-EUS from January 2009 to September 2010 were analyzed. CH-EUS was performed with intravenous administration of an ultrasonographic contrast (Sonazoid) and electronic radial echoendoscope. The graph of time intensity curve (TIC) for pancreatic mass was generated to depict the changes in signal intensity over time within the region of interest (ROI). ROI was placed to cover an area with a pancreatic mass lesion. Based on the analysis of TIC, base intensity before injection (BI), peak intensity (PI), time to peak, and maximum intensity gain (MIG: PI-BI) were calculated. Results. Eight patients with focal AIP and twenty-two patients with PC were evaluated by TIC. PI and MIG of mass lesion of AIP were significantly higher than that of PC (21.4 dB vs. 9.6 dB, 17.5 vs. 6.6). Receiver operating characteristics analysis yielded an optimal MIG cutoff value of 12.5 with high sensitivity and specificity. Conclusion. Pancreatic mass lesions of AIP and PC exhibited markedly different patterns with the TIC. This novel diagnostic modality using TIC generated by CH-EUS might offer an opportunity to improve accuracy in the differential diagnosis between pancreatic mass lesion of AIP and PC.

Clinical usefulness of diffusion-weighted MR imaging for detection of pancreatic cancer: comparison with enhanced multidetector-row CT

PurposeThe aim of this study was to compare diffusion-weighted magnetic resonance imaging (DWI) and multidetector-row computed tomography (MDCT) for detection of primary pancreatic cancer by reviewing images of patients at high risk for pancreatic cancer with main pancreatic duct (MPD) dilatation shown by magnetic resonance cholangiopancreatography (MRCP).MethodsFrom October 2007 to September 2009, 83 patients who had undergone both DWI and MDCT with MPD dilatation were identified and were reviewed by four readers (2 radiologists and 2 gastroenterology fellows). Diagnostic performance in pancreatic cancer detection was evaluated with 95% confidence intervals. Statistically significant differences in the detection of pancreatic cancer between DWI and MDCT were compared by receiver operating characteristics and the confidence of the diagnosis by the paired t test.ResultsThirty-two of 83 patients were diagnosed with primary pancreatic cancer by histological evaluation of 15 surgical and 2 endoscopic ultrasound-guided fine needle aspiration samples, and by the clinical course for 15 lesions. Overall average accuracies of pancreatic cancer detection by the four readers were 84% with DWI and 86% with MDCT.ConclusionPerformance of DWI and MDCT was equivocal for detection of pancreatic cancer in a high-risk population with MPD dilatation. The combination of MRCP and DWI for detection of pancreatic cancer allowed identification of a high-risk population and tumor detection with a single imaging modality with no need for contrast medium.

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.

Does preoperative pancreatic duct stenting prevent pancreatic fistula after surgery? A cohort study

BACKGROUND/OBJECTIVE Postoperative pancreatic fistula remains a major complication after pancreatic surgeries. To prevent pancreatic fistula, one of the employed management strategies is pancreatic duct stenting. The purpose of this study was to evaluate the efficacy and safety of preoperative pancreatic stenting to prevent pancreatic fistula after surgery. METHODS Subjects comprised 18 consecutive patients who underwent pancreatic surgeries. Patients were divided into 2 groups: stenting group (n=7); and non-stenting group (n=11). Complications after stent placement were analyzed. Compared parameters between groups included background, incidence and grading of pancreatic fistula as judged by international study group of pancreatic fistula (ISGPF) criteria, duration until drain removal, and mean maximum level of drain amylase. RESULTS Two patients displayed mild pancreatitis with high serum amylase levels after stenting. No significant differences in background or any other compared parameters to assess drainage effect were identified between stenting and non-stenting groups. Complications related to placement of the stent tube occurred in 4 patients with tube occlusion or cholestasis. CONCLUSIONS Although drainage effect in the stenting group was compared with that in the non-stenting group, no obvious effect was obtained. This procedure seems to require further investigation on indications for postoperative drainage to decrease the incidence of pancreatic fistula.

Initial evaluation of a novel multibending backward-oblique viewing duodenoscope in endoscopic retrograde cholangiopancreatography

A novel multibending backward-oblique viewing duodenoscope was developed to overcome the difficult technical aspect of deep cannulation into the bile duct during endoscopic retrograde cholangiopancreatography (ERCP). The aim of the present study was to evaluate the initial experience of a novel multibending backward-oblique viewing duodenoscope (M-D scope) for ERCP. This was a retrospective review of 23 patients with native papilla who received biliary ERCP with the M-D scope between April and December 2010. The procedures were performed by two well-experienced endoscopists. In all patients, biliary cannulation and therapeutic procedure were successfully completed. In two patients with Billroth I gastrectomy, ERCP were initially attempted with a conventional single-bending duodenoscope, but biliary cannulations were unsuccessful. However, with the use of the M-D scope, biliary cannulation and therapeutic procedures were successfully completed. A novel multibending backward-oblique viewing duodenoscope is safe and feasible for therapeutic and diagnostic ERCP.

Is it safe to perform endoscopic band ligation for the duodenum? A pilot study in ex vivo porcine models.

Abstract Aim: In the digestive tract, endoscopic band ligation (EBL) has been routinely used for the treatment of variceal bleeding and superficial malignancies. In recent years, endoscopic treatments for duodenal varices, adenoma, and cancer have also actively incorporated EBL. Although there have been a number of reports on the risks associated with the use of EBL in the esophagus, stomach, and colon, few studies have focused on EBL in the duodenum. We performed EBL procedures to evaluate the risks associated with the use of EBL in the duodenum. Material and methods: Overall, EBLs were performed at nine sites in duodenum sampled from a pig immediately after sacrifice. Submucosal saline injections were placed in three of the nine studied sites. Results: Regardless of saline injection, the full thickness of the duodenal wall was ligated in all attempts. Conclusions: Routine EBL is not recommended in the duodenum because the risk of perforation is unacceptably high.

EUS-guided rendezvous drainage for pancreatic duct obstruction from stenosis of pancreatojejunal anastomosis after pancreatoduodenostomy.

A 79-year-old man underwent pancreatoduodenectomy with Imanaga reconstruction for an ampullary adenocarcinoma in 2003. After that, he experienced recurrent pancreatitis with a suspicious stenotic pancreatojejunal anastomosis. Although endoscopic drainage through the pancreatojejunal anastomosis was attempted, the stenotic anastomosis could not be located endoscopically. Therefore, endosonography-guided rendezvous drainage through the anastomosis was performed, and endoscopic pancreatic stent placement was successfully completed. Thereafter, the patient did not experience any further attacks of pancreatitis. Endosonography-guided rendezvous drainage is a feasible treatment option for recurrent pancreatitis due to stenosis of pancreatojejunal anastomosis.