Tomoko Tada

Toho University, Tokyo, Tokyo-to, Japan

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Publications (18)54.86 Total impact

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    ABSTRACT: Endoscopic retrograde biliary biopsy samples are frequently too small and inadequate, which makes histological interpretation difficult. We therefore evaluated the diagnostic usefulness of forceps with a larger-sized cup and compared this with standard forceps for biliary biopsy. This prospective study included consecutive patients with extrahepatic biliary strictures who underwent retrograde biliary biopsy between March 2005 and March 2006 at the Toho University Ohashi Medical Center. The standard forceps used were 1.8-mm forceps (FB-39Q, Olympus, Tokyo, Japan) and the large-capacity forceps were 2.2-mm forceps (Radial jaw3, Boston Scientific Inc., Natick, Massachusetts, USA). Four randomized biopsy specimens were taken from each patient, two using each type of forceps. A total of 32 patients (30 with malignant biliary strictures and 2 with benign biliary strictures) were enrolled. The median size of the biopsy samples taken using the standard forceps was 0.68 mm (2) and that using the large-capacity forceps was 1.98 mm (2) ( P < 0.0001). Significant differences between the standard forceps and large-capacity forceps were observed in sensitivity (43 % vs. 70 %), adequacy of the specimens, and submucosal tissue sampling rate. Large-capacity forceps performed better than standard forceps in terms of size, adequacy of the sample, submucosal sampling rate, and detection of neoplasia.
    Endoscopy 10/2010; 42(10):837-41. · 5.74 Impact Factor
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    ABSTRACT: Self-expandable metallic stents (SEMSs) are widely used for palliation of malignant gastric outlet obstruction (GOO). A common complication of their use, however, is stent obstruction caused by tumor ingrowth or hyperplasia. The covered SEMS was designed to prevent these problems. We compared the performance of uncovered and covered SEMSs in patients with GOO. A retrospective study, single center. A tertiary-referral center. Sixty patients with symptomatic malignant GOO. All patients received an uncovered or covered knitted nitinol stent by using the over-the-wire placement procedure. Comparison of the clinical outcome, complications, and the reintervention rate between uncovered and covered stents. Thirty-one patients (mean [+/-SEM] age 72.2 +/- 2.1 years; 16 men) received uncovered SEMSs, and 29 (mean [+/-SEM] age 70.6 +/- 1.7 years; 17 men) received covered SEMSs. The technical success rate was 100% in both groups. No difference in clinical success was seen (90.3% uncovered group vs 86.2% covered group). Regarding early complications (<1 week), one mild case of pancreatitis from the stent covering the papilla occurred in each group. Late complications included reobstruction, migration, bleeding, stent fracture, and perforation. The occurrence of reobstruction did not differ between the 2 groups (3.2% uncovered group vs 10.3% covered group). No difference in migration (0% uncovered group vs 6.9% covered group) was seen. The uncovered group required less frequent reinterventions for stent reobstruction, migration, or stent fracture (3.2% uncovered group vs 20.7% covered group, P = .0490). The uncovered group had 2 major late complications: bleeding and perforation. All 60 patients died, with a median survival time of 51 days and 62 days, respectively. Small-sized, single-center, retrospective study. In palliation for malignant GOO, covered stents were associated with a more frequent need for reintervention than uncovered stents, despite similar outcomes and complications. These results require confirmation in a larger randomized comparison.
    Gastrointestinal endoscopy 02/2009; 69(4):806-12. · 6.71 Impact Factor
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    ABSTRACT: Palliative stenting for gastric outlet obstruction (GOO) offers a more rapid resumption of oral intake than surgical gastrojejunostomy. Clinically, delayed gastric emptying is observed less frequently in patients with enteral stenting. The aim of this study was to conduct a functional assessment of gastric emptying after stent placement for GOO using isotope scanning. Gastric emptying was assessed in 14 patients with GOO (4 female, 10 male; mean age 67.9 years; 8 with gastric cancer; 4 with pancreatic cancer; 1 with biliary cancer; 1 with metastasis) and 10 healthy volunteers (2 female, 8 male; mean age 31.5 years). None of the patients had undergone previous stomach surgery. The patients were studied 1 week after stent placement. Scintigraphy was performed for 2 hours following the ingestion of a labeled liquid meal. Gastric retention was evaluated at 2 hours in both groups. All patients underwent successful placement of stents and were able to resume an oral diet. All stents were fully deployed and no migration was seen at the time of the investigation. Retained gastric activity at 120 minutes (RGA120) was significantly greater in patients than in controls (65.4% vs. 27.5%, p=0.0128). Median survival time was 179 days in patients with T1/2 of 120 min or less and 75 days in patients with T1/2 of over 120 min. The results of our study show that although patients with GOO have resumed oral intake 1 week after stent placement, restoration of gastric emptying is often still incomplete.
    Hepato-gastroenterology 05/2008; 55(81):298-302. · 0.77 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2007; 65(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2006; 63(5).
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2006; 63(5).
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    ABSTRACT: Aims: To investigate the efficacy of extracorporeal shockwave lithotripsy (ESWL) combined with endoscopic treatment for pancreatolithiasis and assess the pancreatic functions after treatment. Patients: Forty-eight cases with pancreatolithiasis in the main pancreatic duct (MPD) treated by ESWL combined with endoscopic treatments were investigated. Methods: The disappearance rate of abdominal symptoms, the frequency of admission for acute exacerbation of pancreatitis before and after treatment, the relationship of removal of pancreatic stones with recurrence and stricture of the MPD, and pancreatic functions before and after treatment were examined. Results: Treatment for pancreatolithiasis improved symptoms in 95.1% and significantly reduced the frequency of admission for 1 year from 1.4 to 0.2 on average. Pancreatic stones were excellently eliminated in 93.8%. Even in cases complicated with the stricture of MPD, combination with endoscopic techniques provided treatment efficacy comparable to that in cases without such complications. The Bentiromide test significantly improved within 3 months after treatment. It improved 1
    Digestive Endoscopy 01/2006; 18(1):16-22. · 1.61 Impact Factor
  • Gastrointestinal Endoscopy - GASTROINTEST ENDOSCOP. 01/2006; 63(5).
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    ABSTRACT: In patients with gastric outlet obstruction (GOO), palliative enteral stenting is a less invasive procedure compared with gastroenterostomy. Most diseases analyzed in previous studies of such stenting were pancreaticobiliary malignancies. We reviewed the medical records of patients with GOO secondary to gastric cancer who were admitted to our institution between September 1994 and September 2004. The outcome of stent placement for GOO was compared with the outcome in patients who underwent palliative open gastrojejunostomy during the same period. Enrolled patients from both groups displayed symptomatic GOO. Patients with recurrent gastric cancer were excluded from this study. Twenty-two patients underwent palliative enteral stenting, and 22 patients were subjected to surgical gastrojejunostomy (bypass). There were no significant differences between the two groups regarding patient baseline characteristics. Technical success and clinical success were obtained in 100% and 77.3%, respectively, of both groups. The operating time was shorter in the stent group (30 vs 118 min; P<0.0001). The time from the procedure to the resumption of food intake was shorter in the stent group than in the bypass group (2 days vs 8 days; P<0.0001). An improvement in performance score after the procedure was observed in both groups (stent group; P=0.0264; bypass group; P=0.0235). No significant differences were observed regarding the possibility of discharge. In patients discharged, the median postoperative hospital stays were 19 days and 28 days (P=0.0558). The median survival periods were 65 days and 90 days. Minor complications were observed in 1 patient in the stent group and in 4 in the bypass group. No mortality or severe complications were observed for either group. Self-expandable metallic stent placement is a safe and efficacious procedure for palliation, with shorter operating time and more prompt restoration of oral intake, compared to surgical alternatives in patients with GOO caused by gastric cancer.
    Journal of Gastroenterology 11/2005; 40(10):932-7. · 3.79 Impact Factor
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    ABSTRACT: Self-expandable metallic stents (SEMS) have recently become widely used. A dedicated stent such as the through-the-scope (TTS) stent has enabled easier placement of SEMS by endoscopists for colorectal obstructions. In Japan, however, the TTS stent is not yet available. Therefore, we have to perform non-TTS placement using esophageal, tracheal or vascular stents for colorectal obstructions. We have developed some modifications which aid the placement of esophageal stents, including increasing the length of the delivery system, and the use of a splinting tube or a double splinting tube. These technical modifications allow markedly better placement of a knitted nitinol Ultraflex esophageal stent for a colorectal obstruction. They allowed us to even place SEMS in the proximal colon without difficulty, and in all patients we treated. Therefore, with some technical modifications, it is feasible to use an esophageal stent for proximal colonic obstruction.
    Digestive Endoscopy 09/2005; 17(4):334 - 337. · 1.61 Impact Factor
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    ABSTRACT: With the conventional pull method of PEG placement, there is a significant risk of wound infection from contamination of the gastrostomy catheter as it passes through the oral cavity. This study compared the occurrence of peristomal wound infection associated with PEG placement with and without use of an overtube. Consecutive patients with dysphagia were randomized to undergo PEG placement with (Group I) or without (Group II) an overtube. For each patient, the peristomal area was evaluated daily for 1 week after PEG placement. The presence of erythema and of exudate were scored on a scale of 0 to 4; induration was scored on a scale of 0 to 3. Criteria for infection were a maximum combined score of 8 or higher, or the presence of microscopic and microbiologic evidence of suppurating exudate. In each group, cefazolin was administered prophylactically (2 g/d intravenously) for 3 days. For patients who had received an antibiotic(s) before PEG placement, the same antibiotic(s) was used. All procedures in both groups were performed by one of two investigators who used the pull method. A total of 76 patients were randomized; 3 were excluded from analysis, because death occurred within 1 week after the procedure. Two of 3 deaths were procedure-related (aspiration pneumonia in Group I, peritonitis in Group II). Data for 37 patients in Group I and 36 in Group II were analyzed. There was no significant difference between the groups with respect to baseline characteristics. The occurrence of peristomal infection within 1 week of PEG was significantly lower in Group I compared with Group II (2 vs. 12; p = 0.0029). The mean daily combined scores in Group I also were significantly lower than those in Group II ( p < 0.0001), and the median maximum parameter scores in Group I were significantly lower than those in Group II (erythema, p = 0.0062; induration, p = 0.0390; exudate, p < 0.0001), although the nominal significance for induration was removed by correction for the multiple testing of data. One patient excluded from Group II died from sepsis because of procedure-induced peritonitis. Among the 73 enrolled patients, there was no procedure-related mortality or clinically important wound infections that required surgical intervention in either group. Use of an overtube during PEG placement reduces the risk of peristomal wound infection.
    Gastrointestinal Endoscopy 04/2005; 61(4):522-7. · 5.21 Impact Factor
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    ABSTRACT: Stent placement in palliation of unresectable colon cancer is an alternative to surgical treatment. The through-the-scope stent for the exclusive treatment of colorectal cancer is not available in Japan. This report describes the use of an esophageal stent and the technical modifications required for its success in the treatment of colorectal strictures. We describe various technical strategies for colorectal stent placement and report on the outcomes. Medical records of patients who underwent palliative colonic stenting between June 1997 and March 2003 were reviewed retrospectively, and the clinical outcome was evaluated. Insertion of a metallic esophageal stent was attempted in 12 patients (mean age, 73.0 years; 5 male, 7 female). Location of the stricture was in the rectum in 4 patients and in the sigmoid, descending, or transverse segments of the colon in 5, 1, and 2 patients, respectively. Two patients had recurrent colon cancer after surgery. The remaining 10 patients did not undergo surgery. Stent placement was technically successful in 11 patients, giving a technical success rate of 92%. Following successful stent placement, all but 1 patient obtained clinical success, generating a clinical success rate of 83%. Late complications occurred in 4 patients and included 2 migrations, 2 bleeds, and 1 obstruction. The complication rate of the procedure was 33.3%. There was no mortality or severe complications. The median survival period was 120 days. Stent placement can be considered safe and effective palliation for unresectable colorectal cancer. With technical modification of an esophageal stent, this procedure is now feasible. Stent placement in palliation of unresectable colon cancer is an alternative to surgical treatment. The through-the-scope stent for the exclusive treatment of colorectal cancer is not available in Japan. This report describes the use of an esophageal stent and the technical modifications required for its success in the treatment of colorectal strictures. We describe various technical strategies for colorectal stent placement and report on the outcomes.
    Journal of Gastroenterology 02/2004; 39(4):334-8. · 3.79 Impact Factor
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    ABSTRACT: Palliative treatment for duodenal stenosis with an enteral stent is effective in enhancing the quality of life of patients with duodenal obstruction. There have been no thorough comparisons of duodenal stent placement with standard surgical gastrojejunostomy. The present study evaluated the outcome of duodenal stent placement and surgical gastrojejunostomy for palliation of duodenal stenosis caused by pancreaticobiliary malignancies. Medical records for patients who underwent palliative enteral stenting during the past 9 years were retrospectively reviewed, and the patients' clinical outcome was compared with that in patients who underwent open surgical gastrojejunostomy during the same period. Patients who underwent prophylactic gastrojejunostomy were excluded from the study. Twenty patients (11 men, nine women; mean age 71.8 years) with pancreaticobiliary malignancy underwent palliative enteral stenting (stent group). Nineteen patients (12 men, seven women; mean age 68.7 years) with pancreaticobiliary malignancies underwent surgical gastrojejunostomy (bypass group). In the stent group, the diagnoses were 12 pancreatic cancers, six gallbladder cancers, one bile duct cancer, and one ampullary cancer. In the bypass group, the diagnoses were 14 pancreatic cancers and five gallbladder cancers. There were no significant differences between the two groups with regard to clinical background. Both procedures were successful. There were no differences between the two groups with regard to the technical or clinical success rates, patient survival, possibility of discharge, need for parenteral nutrition, or incidence of complications. However, the time from the procedure to resumption of food intake was shorter in the stent group than in the bypass group (1 day vs. 9 days; P < 0.0001). Improvement in the performance score after the procedure was observed more frequently in the stent group (65 % vs. 26.3 %; P < 0.05). In terms of the median hospital stay from the time of the procedure to the time of initial discharge home (12 patients vs. nine patients), there was no statistical difference (15 days vs. 30 days) due to the small size of the sample. There was no procedure-related mortality in either group. Palliative stent placement was more beneficial than surgical gastrojejunostomy in enhancing the quality of life of patients with duodenal obstruction due to pancreaticobiliary malignancies.
    Endoscopy 02/2004; 36(1):73-8. · 5.74 Impact Factor
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    ABSTRACT: PEG by the conventional pull method has the potential drawback of being associated with a higher frequency of wound infection, presumably caused by contamination of the gastrostomy catheter as it passes through the oral cavity. This study investigated the occurrence of peristomal wound infection after PEG placement by using the pull and introducer techniques. Between September 1999 and May 2002, consecutive patients with dysphagia for whom PEG was recommended were enrolled in the study and randomly assigned to two groups: PEG with the introducer method (Group I) or PEG with the pull method (Group II). The peristomal area of each patient was evaluated on a daily basis for one week after PEG. Erythema and exudate were scored on a scale from 0 to 4 and induration on a scale of 0 to 3. Criteria for infection were a maximum combined score of 8 or higher, or the presence of microscopic and microbiologic evidence of suppurating exudate. In each group, the endoscope was passed once during the procedure, and an antibiotic (piperacillin) was given prophylactically. All procedures were performed by one investigator with the assistance of another physician. Of the 60 patients enrolled, 30 were assigned to each group. PEG was successful in all patients. One patient was excluded from each group because of death (Group I, stroke; Group II, myocardial infarction) within one week of the procedure. Therefore, 58 patients, 29 in each group, were evaluated. There was no significant difference between the groups in terms of clinical parameters (age, gender, disease, performance score, mode of previous feeding, and recent antibiotic exposure). The occurrence of peristomal infection within one week of PEG was lower in Group I (introducer method) (0 vs. 9; p = 0.00094). The mean daily combined scores in Group I were significantly lower than those in Group II. Median of maximum parameter scores in Group I were significantly lower than those in Group II. There were no procedure-related mortalities or clinically significant wound infections that required surgical intervention. The risk of peristomal wound infection after PEG is lower with the introducer method compared with the pull method.
    Gastrointestinal Endoscopy 07/2003; 57(7):837-41. · 5.21 Impact Factor
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    ABSTRACT: Background:  Intraductal papillary-mucinous pancreatic tumors (IPMT) are intraductal lesions formed by mucin-producing epithelium, which proliferates in a papillary pattern, and presents a spectrum from hyperplasia to adenocarcinoma. The value of intraductal ultrasonography (IDUS) for excluding malignancy has not been assessed in a case series previously.Methods:  Intraductal ultrasonography was performed in 17 patients with IPMT (12 with adenocarcinoma and five with adenoma) between November 1993 and June 2002. Intraductal ultrasonography was used to determine the maximum height and maximum cross-sectional area of protruding lesions. Results were compared after dividing the tumors into three groups: a benign lesion group, a non-invasive cancer group, and an invasive cancer group. The resection line was located over 10 mm from the edge of the protruding lesion visualized by intraductal ultrasonography.Results:  All adenocarcinomas had a height ≥ 5 mm and all benign lesions had a height ≤ 3 mm, with this difference being significant (P = 0.0034). The height of non-invasive and invasive cancer was similar. The maximum cross-sectional area of the protrusion was smaller for benign lesions (≤ 15 mm2) than for non-invasive cancer (≥ 34 mm2, P = 0.0034). The cross-sectional area of the protrusion was greater in patients with invasive cancer than in those with non-invasive cancer (P = 0.0367). All surgical margins have remained clear and no patient has suffered from a recurrence during 1 to 8 years of follow-up computed tomography and ultrasonography.Conclusions:  Intraductal ultrasonography can distinguish benign from malignant IPMT based on the height and maximum cross-sectional area of the protruding tumor.
    Digestive Endoscopy 06/2003; 15(3):196 - 199. · 1.61 Impact Factor
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    ABSTRACT: Endoscopic retrograde cholangiopancreatography (ERCP) is sometimes unsuccessful because the anatomy of the papilla of Vater precludes cannulation by routine means. The efficacy of a new flexible tip cannula (the Swing Tip) was studied in patients in whom routine ERCP was unsuccessful. The Swing Tip cholangiographic catheter has an articulation at its tip which allows the tip to be flexed from 90 degrees to 30 degrees. Routine cholangiography was successful in 175 of 195 patients in whom it was attempted between September 2000 and November 2001. ERCP with the Swing Tip catheter was attempted in the 20 patients in whom ERCP had failed. In 17 of 20 patients, we attempted to insert the Swing Tip catheter into the common bile duct to perform cholangiography. Insertion was successful in 11 patients and unsuccessful in six. There were no complications related to the procedure. The Swing Tip catheter is a useful adjunct to standard ERCP catheters for patient in whom standard techniques are unsuccessful.
    Endoscopy 09/2002; 34(8):628-31. · 5.74 Impact Factor
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    ABSTRACT: The outcome of stenting gastric outlet stricture is favorable compared with a bypass operation which has significant morbidity and mortality. In Japan, this procedure is particularly complicated by a lack of enteral stents. We report some technical stratagems for stent placement for gastric outlet strictures. Between February 1993 and July 2001, 23 patients with gastric outlet strictures (14 men, nine women; mean age 72 years) underwent stent placement using an esophageal stent system. The Ultraflex or Z-stents were used in 18 or five patients, respectively. With the Ultraflex, we increased the length of the delivery system. Some patients underwent stent placement with the help of endoscopic assistance with a grasping forceps or a home-made sheath. The metal stent was successfully inserted in all patients. There were no complications during the procedure. Migration occurred in two out of five patients treated with the Z-stent, whereas there was no migration in patients treated with the Ultraflex stent. In two patients, curable pancreatitis was caused by pressure on the duodenal papilla. One of these patients also experienced bile stasis which required biliary decompression. There were three cases of obstruction, caused by tumor ingrowth (1), hyperplasia (1) and stent fracture (1); recanalization by an additional stent placement and/or cutting stent filaments was successful. All the patients died, with a median survival period of 52 days. There was no procedure-related mortality. With some technical modification, stent placement for gastric outlet stricture, even using an esophageal stent, is feasible. This procedure offers good palliation with no major complications.
    Endoscopy 06/2002; 34(5):402-6. · 5.74 Impact Factor
  • Digestive Endoscopy 01/2000; 12(Suppl. S1):21-23. · 1.61 Impact Factor