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Biomedical subjects

T L Tio

Publications and source records attributed to T L Tio.

At least 19 recordsLinked to original sources

Endoscopic ultrasonography in patients with gastrinomas.

Placing the endoscopic ultrasound transducer in the descending duodenum, the duodenal bulb and the stomach, all the pancreas can be imaged. Endoscopic ultrasonography is a sophisticated imaging technique able to accurately diagnose and localize primary endocrine tumours of the pancreas (mostly insulinoma and gastrinoma) which may not be detectable with other imaging modalities. Furthermore, endoscopic ultrasonography-guided fine needle aspiration allows cytology and/or biopsy specimens to be obtained, that are crucial for clinicians in decision making. In the case of extrapancreatic endocrine tumours, which are often localized in the second and third part of the duodenum, endoscopic ultrasonography may have difficulty in localizing small and flat lesions. In this case, the initial step would be identification of duodenal nodules by duodenoscopy and thereafter, a catheter echoprobe can be inserted to identify the extent of submucosal lesion. Then gastroduodenal nodules found by endoscopy and confirmed by endoscopic ultrasonography can be removed endoscopically using the technique of mucosectomy. In the case of large pancreatic lesions, endoscopic tattoo with dye-India ink or methylene blue may become helpful for the surgeon to perform local resection via duodenostomy.

Endosonography↗

Mucosal iodine staining improves endoscopic visualization of squamous dysplasia and squamous cell carcinoma of the esophagus in Linxian, China.

BACKGROUND: In previous studies in the high risk population of Linxian, China, the majority of foci of high grade (moderate and severe) squamous dysplasia (HGD) and invasive squamous carcinoma (CA) of the esophagus were associated with endoscopically visible lesions that could be targeted for biopsy, but some foci of HGD were missed by routine endoscopic examination. This study examined whether spraying the mucosa with Lugol's iodine solution, which stains normal epithelium brown but leaves dysplasia and carcinoma unstained, could improve endoscopic detection and delineation of these lesions. METHODS: Two hundred twenty-five Linxian adults with balloon cytologic evidence of dysplasia or carcinoma underwent endoscopy. All visible lesions were described and photographed before and after staining with 1.2% Lugol's iodine solution. Biopsies were taken from all lesions visible before staining, from all unstained lesions (USLs) after applying the stain, and from representative control areas of stained mucosa. RESULTS: Two hundred fifty-three USLs and 255 control sites were biopsied. No complications occurred. Ninety-four biopsy sites contained HGD and 20 contained CA. Before staining, the sensitivity of visible lesions for identifying HGD or CA was 62%, and the specificity was 79%. After staining, the sensitivity of USLs for identifying HGD or CA was 96%, and the specificity was 63%. Eighty-eight percent of the HGD and CA lesions were larger or more clearly defined after staining. The diagnostic lesions in 17 of 31 patients with moderate dysplasia (55%), 8 of 35 patients with severe dysplasia (23%), and none of the 19 patients with invasive carcinoma (0%) were identified only after staining. CONCLUSIONS: Mucosal iodine staining improved endoscopic detection and delineation of HGD and CA in these patients. This simple technique is highly sensitive for identifying these precursor and invasive squamous lesions, and it should be used whenever optimal visualization of squamous mucosal abnormalities is required.

Adult↗

Endosonographic differentiation of benign and malignant stromal cell tumors.

BACKGROUND: Endosonography (EUS) is a valuable technique for diagnosing gastrointestinal stromal cell tumors. However, EUS features that are predictive of malignancy in these tumors have not been defined. METHODS: Videotapes and photographs of EUS examinations performed prior to surgical resection of 35 stromal cell tumors (9 malignant) were blindly reviewed by a single examiner. EUS features associated with malignancy were determined. Interobserver agreement in interpreting these features was then measured among a panel of five expert endosonographers who judged EUS videotapes of 35 resected stromal cell tumors (10 malignant). RESULTS: Stepwise logistic regression analysis demonstrated that tumor size (diameter > 4 cm), irregular extraluminal border, echogenic foci, and cystic spaces were independently associated with malignancy in stromal cell tumors (p < 0.05). Interobserver agreement for irregular extraluminal border, echogenic foci, and cystic spaces, as measured by mean kappa statistic, was 0.43, 0.39, and 0.28, respectively. For the five experts, the sensitivity for detecting malignancy ranged between 80% to 100% when at least two of the three features were judged to be present. The likelihood of finding malignancy ranged between 0% to 11% for the experts when all three features were judged absent. CONCLUSIONS: Tumor size and certain EUS features are useful for predicting malignancy in stromal cell tumors. Absence of these features indicates benign disease. Agreement among experts in interpreting these EUS features is fair to moderate.

Diagnosis, Differential↗

A new system for defining endoscopic complications emphasizing the measure of importance.

BACKGROUND: Currently, there are no satisfactory systems for defining, classifying, and/or scoring endoscopic complications, although it would be important for quality assurance, comparative studies, and outcomes research. Recently the term "negative outcomes" was proposed rather than "complications," and an approach that incorporates "measures of importance" was added to compare negative outcomes. METHODS: A system was developed that defines, classifies, and grades negative outcomes with a scoring system based on measures of importance. Information was recorded on a Morbidity and Mortality (M & M) form, which was used at a monthly quality assurance (M & M) conference. Several measures of importance related to the immediate negative outcome (O) were quantified (effect of the complication on completion of the endoscopy, change in level of care, change in number of hospital days, necessity for new invasive procedures). The disability (D), defined as a residual or chronic negative outcome caused by the complication, was characterized and scored. Death (D) was also characterized, the value varying with circumstances. As a quantitative measure, an overall ODD score was used. RESULTS: One hundred twenty-three negative outcomes were retrospectively classified using the new M & M form and the ODD score was applied for 117 complications. Complications were ranked according to the ODD score. CONCLUSION: A system for defining, classifying, and grading negative outcomes of endoscopic procedures is proposed with a quantitative scoring system that emphasizes measures of importance. The ODD score looks at the immediate negative outcome and also the separate long-term issues of disability and death.

Documentation↗

Staging of ampullary and pancreatic carcinoma: comparison between endosonography and surgery.

BACKGROUND: The aim of the study was to update our previously published data on the clinical TNM staging of ampullary and pancreatic carcinoma by endosonography. METHODS: Endosonography was performed in 70 patients with pancreatic cancer and in 32 patients with ampullary carcinoma. TNM staging was carried out before surgery and compared with findings of histology and/or surgery. RESULTS: Endosonography was accurate in staging the depth of tumor invasion. Early-stage carcinomas could be distinguished from advanced cancers. Nonresectability was accurately assessed on the basis of vascular involvement using real-time ultrasound. Tumor compression due to peritumoral pancreatitis and direct tumor invasion into the base of the mesocolon could not be diagnosed by endosonography. The overall accuracy in tumor staging for pancreatic and ampullary carcinomas was 83.6% and 84.4%, respectively. Endosonography was accurate in diagnosing regional lymph node metastases but not accurate in defining nonmetastatic lymphadenopathy and distant metastases. CONCLUSION: Endosonography was accurate in staging tumor stage and lymph node metastases. Minimally invasive methods of resection for superficial ampullary cancers should be based on endosonography staging.

Ampulla of Vater↗

The TNM staging system.

The new TNM staging system for cancer has great importance because of its applicability for imaging techniques, particularly clinical staging by EUS. The close correlation between clinical (EUS) and pathologic staging permits clinicians to define the strategy for treatment based on the stage of the cancer. In cases where lymph node metastasis is suspected, EUS-guided FNA can be performed for confirmation of this diagnosis by cytology. In the era of minimally invasive surgery, EUS will become the most important diagnostic modality for defining early stage malignant disease. In such cases endoscopic or surgical resection can be performed. When a tumor is shown by EUS to be nonresectable, it will become important to avoid explorative surgery. Despite some limitations, both the TNM classification and EUS clinical staging will be used with increasing frequency in the clinical management of patients with cancer. Furthermore, refinements in the TNM staging system, such as adoption of subclassifications of early cancers and clarification of the definition of regional lymph node involvement, will be necessary to optimize clinical staging. Technologic improvement of EUS instruments, particularly in miniaturization of the echoprobe, will improve the integration of EUS as a routine procedure for cancer staging.

Endoscopes, Gastrointestinal↗

[Mini-probe ultrasound of the upper gastrointestinal tract--1995 state of the art and perspectives. Workshop on Mini-Probe Ultrasound in Gastroenterology, Münster, 28 October 1995].

Endoscopic ultrasound (EUS) allows for intraluminal sonographic imaging of the oesophagus, stomach, pancreatobiliary duct system, the papilla of Vater, as well as the colon and rectum. EUS has proved valuable for diagnosis and staging of tumours of the upper intestinal tract. EUS can also provide valuable additional information concerning lesions that cannot be immediately classified. As doing this involves, first, removal of the conventional endoscope and, second, insertion of the echo endoscope, EUS is not suitable for routine examinations. Therefore EUS has remained an independent endoscopic diagnostic modality. Moreover, due to their diameter conventional echoendoscopes cannot be inserted into the pancreatobiliary duct system. Fine calibre high frequency ultrasound probes promise a resolution of less than 2 mm in diameter. The following report is a summary of a one-day workshop which took place in Muenster, Germany on Oct. 28, 1995. Its goal was to define the current state of the art of miniaturised endoscopic ultrasound probes in the field of gastroenterology. During this workshop, possible clinical applications for diagnosis, therapy, as well as follow-up were described and discussed. The potential of miniaturised endoscopic ultrasound probes was explored in terms of possible future technical developments.

Endoscopy, Gastrointestinal↗

Prognosis of esophageal cancers preoperatively staged to be locally invasive (T4) by endoscopic ultrasound (EUS): a multicenter retrospective cohort study.

BACKGROUND: Endosonography is a significant advance in the preoperative staging (TNM classification) of esophageal cancer. Its accuracy for evaluating depth of tumor invasion is over 80%. METHODS: A multicenter retrospective cohort study of patients with esophageal carcinomas defined to be invasive (T4) by endosonography was performed to compare the survival of surgically and nonsurgically treated patients. Median survival time, overall mortality, and Kaplan-Meier survival curves were compared by treatment group. Univariate and Cox regression analysis were used to evaluate the effects of various prognostic factors and treatment on the risk of death. RESULTS: A total of 79 patients were studied. The surgical group (Group I, n = 42) was significantly younger and had more distal tumors (adenocarcinomas) than the nonsurgical group (Group II, n = 37). Endosonography was significantly more accurate than CT scanning in identifying tumor invasion (87.5% versus 43.8%, respectively, p = .0002). Overall mortality rate was not significantly different between treatment groups; 59.5% of the surgical group and 64.9% of the nonsurgical group were dead at follow-up (p = 0.65). Similarly, the median survival times of Group I and Group II patients were similar (5.2 and 7.0 months, respectively, p = 0.50). Survival curves for the two groups were almost overlapping (log rank test, p = 0.84). Even after adjusting for age, histologic diagnosis, tumor location, and regional lymph node status, surgical treatment did not significantly influence survival (p = 0.24). CONCLUSIONS: Endosonography accurately identifies patients with invasive T4 tumors who have a poor prognosis. This prognosis is independent of mode of therapy.

Adenocarcinoma↗

Endosonography of gastroesophageal varices: evaluation and follow-up of 76 cases.

Endosonography was performed in 76 patients who had endoscopically detected gastroesophageal varices or questionable submucosal lesions, or who were being evaluated for pancreatic carcinoma or pancreatitis. The result were compared with surgery or autopsy results. The patients were divided retrospectively into four groups. Group 1 consisted of 6 patients who underwent surgery or autopsy. Five esophageal varices and 1 fundic varix were diagnosed with endosonography and confirmed histologically. Group 2 consisted of 29 patients undergoing sclerotherapy. Intramural thickening of the esophagus and extramural collaterals were found in 20 of 22 patients, respectively. Endoscopy revealed fibrosis in 10 patients. Group 3 consisted of 16 patients evaluated for pancreatic disease. Fifteen fundic varices, 6 cardiac varices, and 5 extramural collateral veins were found by EUS. Group 4 consisted of 16 patients with questionable submucosal lesions and 9 patients with lesions recognized endoscopically as varices. EUS found varices in all 25 patients. In conclusion, EUS is an important procedure in the diagnosis and follow-up of gastroesophageal varices, and in the identification of questionable abnormalities found endoscopically. The effect of sclerotherapy can be demonstrated as mural thickening with disappearance of submucosal varices.

Case-Control Studies↗

Large gastric folds evaluated by endoscopic ultrasonography.

Diffuse large gastric folds may lead to difficult clinical diagnosis particularly in biopsy-negative cases. In the differential diagnosis Menetrier's disease or hypertrophic gastritis and linitis, EUS is very helpful because of its ability in imaging the location of mural abnormality. In initially negative biopsy for linitis, EUS can help the clinician in selecting the optimal site for positive biopsy. In gastric NHL, EUS can be helpful in selecting the appropriate candidate for surgery and in monitoring the response to chemotherapy and irradiation. EUS appears to be more suitable for TNM staging than the Ann Arbor classification for gastric NHL. The routine use of EUS-guided FNA should be attempted for obtaining the tissue diagnosis.

Biopsy, Needle↗

Proximal bile duct tumors.

This article describes the present and future clinical applications of endoscopic ultrasound (EUS) in the evaluation of Klatskin tumors. Topics discussed include instruments, investigation techniques, EUS interpretation, fine needle aspiration cytology, and color Doppler ultrasonography.

Bile Duct Neoplasms↗

Endoscopic ultrasonography of perigastrointestinal lymph nodes.

The introduction of endoscopic ultrasonography (EUS) has opened a window in the diagnosis of the perigastrointestinal lymph nodes. Initial euphoria has been sobered by the fact that false-positive and false-negative diagnoses may occur. We review here the use of EUS to stage gastrointestinal cancer, and particularly to predict the presence or absence of lymph-node metastases. The role of EUS-guided fine-needle aspiration using a radial scanner or a curved array echoendoscope is mentioned.

Abdomen↗

Endoscopic ultrasonography of perianorectal fistulas and abscesses.

In this article we describe the history, instrument, indications, and results of endoscopic ultrasonography (EUS) in the evaluation of perianorectal fistulas and abscesses. EUS has been reported to be helpful in the management of patients with Crohn's disease or colitis associated with fistulas and abscesses, due to its clear imaging of the leasion and valuable topographic anatomical information. Recent studies point out the relationship between EUS and electromyography. We believe EUS will become a standard procedure in the management of these complex disease processes.

Abscess↗