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Biomedical subjects

P Vilmann

Publications and source records attributed to P Vilmann.

At least 37 records · Page 2Linked to original sources
PubMed1999

Insulinoma diagnosed by endoscopic ultrasonography-guided biopsy.

Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is a new technique that seems to expand the utility of EUS, making definitive diagnosis of pancreatic lesions possible. However, the exact indications for the method, as well as its limitations, are not fully defined. We report on a patient with an insulinoma in the tail of the pancreas undetected by other imaging modalities that was conclusively diagnosed by EUS-FNA. Endoscopic ultrasonography is a unique imaging modality for localization of small pancreatic lesions. In combination with FNA, it represents a significant improvement for the exact diagnosis of these tumors.

Adult↗
PubMed1998

One-step endosonography-guided drainage of a pancreatic pseudocyst: a new technique of stent delivery through the echo endoscope.

We report here the first case of a one-step endosonography(EUS)-guided pseudocyst drainage. A prototype large channel curved array echo endoscope (Pentax FG-38 UX) and a prototype delivery system for placement of an endoprosthesis was used for the procedure. The delivery system (GIP MedicinTechnik GmbH/Medi-Globe Corporation) consists of a handle part with a piston, a metal ring sheath, a plastic catheter with a diathermy needle and a double pigtail endoprosthesis (8.5 Fr). When mounted on the endoscope the endoprosthesis can be advanced out of the distal end of the endoscope. The introduction of the stent as well as the stent release can be monitored entirely by ultrasound. The procedure was tested in a 76-year-old woman with a pseudocyst measuring 60 mm in diameter located in the tail of the pancreas. The procedure was well tolerated by the patient, and there were no procedural complications. The advantage of a large channel echo endoscope and our new prototype delivery system is that the endoprosthesis can be inserted in to a pancreatic cyst guided exclusively by EUS without exchange of endoscopes, catheters or guide wires. Further studies are warranted.

Aged↗
PubMed1997

Endosonography-guided fine-needle aspiration biopsy: diagnostic accuracy and complication assessment.

BACKGROUND & AIMS: Endosonography-guided fine-needle aspiration biopsy (EUS-FNA) permits cytological confirmation of EUS findings. A multicenter prospective evaluation of EUS-FNA for primary diagnosis, staging, and/or follow-up purposes was undertaken. METHODS: EUS-FNA was performed in 457 patients with 554 lesions. Clinical (n = 218) or histopathologic (n = 256) confirmation was available in 192 lymph nodes, 145 extraluminal masses, 115 gastrointestinal wall lesions, and 22 cystic lesions. RESULTS: EUS-FNA sensitivity, specificity, and accuracy was 92%, 93%, and 92% for lymph nodes, 88%, 95%, and 90% for extraluminal masses, and 61%, 79%, and 67% for gastrointestinal wall lesions, respectively. The sensitivity and accuracy for lymph nodes and extraluminal masses was superior to that for gastrointestinal wall lesions. When EUS-FNA was compared with EUS size criteria in lymph node evaluation, specificity (93% vs. 24%) and accuracy (92% vs. 69%) were superior, whereas sensitivity (92% vs. 86%) was similar. The accuracy of EUS-FNA in patients with previously failed biopsy procedures was 81% (73 of 90). Five nonfatal complications occurred for a rate of 0.5% (95% confidence interval, 0.1%-0.8%) in solid lesions vs. 14% (95% confidence interval, 6%-21%) in cystic lesions. CONCLUSIONS: EUS-FNA accurately and safely evaluates solid peri-intestinal lesions and improves lymph node staging accuracy.

Abdomen↗
PubMed1997

Early detection of recurrent hepatocellular carcinoma by endosonographically guided fine-needle aspiration biopsy.

Fine-needle aspiration guided by endoscopic ultrasonography (EUS) has shown promising results in establishing the cytological diagnosis of lesions identified during endoscopic ultrasound examinations. We report here on a case of recurrent hepatocellular carcinoma diagnosed by EUS-guided biopsy in which curative resection was possible as a result of early diagnosis.

Biopsy, Needle↗
PubMed1996

Endoscopic ultrasonography and real-time guided fine-needle aspiration biopsy of solid lesions of the mediastinum suspected of malignancy.

STUDY OBJECTIVE: The study details our preliminary experience with endoscopic ultrasonography (EUS) guided fine-needle aspiration biopsy (FNAB) of mediastinal masses suspected of malignancy. DESIGN: Prospective uncontrolled study. PATIENTS: Nine patients had lesions suspected of malignancy ranging from 1 to 9 cm in diameter in various locations of the mediastinum. INTERVENTIONS: The EUS examination was performed with a gastroscope (Hitachi/Pentax FG-32 UA) equipped with an adjustable 5- or 7.5-MHz curved array ultrasonic transducer. The scanning plane is in the long axis of the endoscope allowing endosonographically guided biopsy to be performed. A 21-gauge (0.8 mm), full-length steel needle housed in a biopsy handle (type: Hancke/Vilmann; GIP-Medizin Technik; Grassau, Germany) was used for the biopsies. RESULTS: Nine patients had biopsy specimens taken from 13 lesions. The total number of needle passes was 18 (range, 1 to 3; median, 1.4). The cytologic diagnosis was conclusive for cancer in ten lesions and consistent with a benign lesion in three lesions. All ten malignant diagnoses and two benign diagnoses were confirmed either by operation or follow-up. In the last patient with lung cancer, a final diagnosis of the EUS-guided biopsy of an enlarged lymph node could not be obtained. No false-positive or negative biopsy diagnoses were recorded. The biopsy procedure was well tolerated by all patients, and there were no complications. CONCLUSIONS: EUS-guided aspiration biopsy is a significant advance in the differentiation between malignant and benign lesions of the mediastinum carrying a high diagnostic potential.

Aged↗
PubMed1995

Endoscopic ultrasound scanning of the upper gastrointestinal tract using a curved linear array transducer: "the linear anatomy".

During the last few years endoscopes with electronic array transducers have been introduced, making EUS-guided biopsy possible. However, only a few studies have been published with this kind of instrument. In this article, the EUS examination procedure and the normal anatomy of the upper gastrointestinal tract using a curved linear array transducer are described.

Digestive System↗
PubMed1993

Endosonographically-guided fine needle aspiration biopsy of malignant lesions in the upper gastrointestinal tract.

A new method of endoscopic ultrasound (EUS) guided fine needle aspiration using an ultrasonic endoscope with a curved array transducer mounted in front of the optic lens was developed. As a result of the sector shaped sound field and the direction of the scanning plane it was possible to visualise ultrasonically a needle inserted through the biopsy channel. EUS guided biopsy was performed in 37 patients (with 39 lesions) using three types of needles. Based upon initial testing of several prototype needles a 160 cm long, 0.8 mm diameter needle placed in a Teflon catheter was developed after preliminary results with the first two types were unsatisfactory (positive results for malignancy in 3/11 and 4/8 cases). The third prototype was tested in seven patients with malignant tumours of the upper GI tract. In these patients EUS guided biopsy was positive for malignancy in 7 of 8 solid lesions. Problems related to the technique and criteria for a successful outcome are discussed. The preliminary results show that it is possible to advance a needle into a malignant lesion inside or outside the GI wall during EUS examination and aspirate material for cytologic examination from various lesions. Controlled studies are needed to determine the indications for use and the accuracy of the technique.

Biopsy, Needle↗
PubMed1992

Ultrasound image of human masseter muscle related to bite force, electromyography, facial morphology, and occlusal factors.

The thickness of the human masseter muscle, corresponding approximately to a cross-section at the most bulky part of the superficial portion, was measured by ultrasound scanning at three sites 1 cm apart. The study included 13 women, 21-28 yr of age, with a minimum of 24 teeth and without craniomandibular disorders. Ultrasonography produced a well-defined depiction of the muscle with distinct tendinous structures. The average thickness at the measuring sites varied from 8.83 to 11.08 mm with the muscle relaxed, and increased significantly during contraction to average values between 9.84 and 12.57 mm. The study showed a connection between measures of masseter thickness and function of the muscle, as well as parameters generally associated with masseter muscle function. Muscle thickness at the voluminous anterior part of the superficial portion was systematically and significantly correlated to bite force, occlusal tooth contact and cephalometric data (anterior face height, vertical jaw relation and mandibular inclination). In conclusion, ultrasound scanning gave an uncomplicated and a reproducible access to parameters of jaw muscle function and its interaction with the craniomandibular system.

Adult↗
PubMed1991

[Endoscopic ultrasound scanning of the upper gastrointestinal canal].

Endoscopic ultrasound scanning (EUL) of the upper gastro-intestinal canal has rendered apparently very meticulous assessment of pathological conditions in and around the oesophagus, stomach and the duodenum possible during recent years. On account of the close contact with the mucosa, high-frequent ultrasound transducer with great solubility capacity are employed. The wall of the gastrointestinal canal may thus be presented and subdivided into five layers. The ultrasound gastroscope most employed at present is lateral visualizing gastroscope with a mechanically rotating sector scanner mounted distal to the optic. On the basis of the literature, the technique of the examination and the hitherto employed indications for EUL are reviewed. International attention has been focussed on employment of EUL for preoperative subdivision of tumours in the oesophagus, stomach, pancreas and biliary passages into stages. Individual centres have reported promising results compared with existing forms of examination such as CT, conventional radiography, endoscopy and external ultrasound scanning. It is concluded that the necessary apparatus has not yet been fully developed. In addition, more numerous and more extensive prospective investigations are necessary before EUL may possibly be considered as a routine method of examination.

Duodenal Neoplasms↗
PubMed1991

[Endoscopic ultrasound scanning of the upper gastrointestinal tract. Preliminary results].

International interest in endoscopic ultrasonic scanning (EUL) for assessment of mural and extramural pathology in and around the upper gastrointestinal tract has increased during recent years. Since 1. February 1989, the surgical gastroenterological department D in cooperation with the ultrasonic laboratory in Gentofte Hospital has undertaken EUL on selected patients employing a recently developed Picker-Pentax ultrasonic gastroscope. The apparatus consists of a forward viewing fibreoptic gastroscope with a 5 MHz curved electronic ultrasonic transducer mounted immediately behind, the optic. The plans of scanning is longitudinal in the length of the gastroscope. On the basis of in vitro ultrasonic examinations and EUL in a total of 80 patients during a period of 12 months, the preliminary experience with the above mentioned apparatus is described. It is concluded that the 5 MHz transducer is not sufficiently high frequent for detailed examination of the mucosa and the walls of the gastrointestinal canal whereas deep penetration and imaging of the surrounding organs and structures is satisfactory. The method demands great endoscopic routine and extensive UL experience as the UL sectional image is unpredictable and difficult to define, one of the reasons being that the transducer is not visible through the gastroscope. The indications for employing the apparatus described here are not completely elucidated and assessment of the diagnostic certainty of the method requires more numerous and controlled investigations. The authors consider that EUL with linear array transducer as the most recent invention will result in increased diagnostic information in gastroenterology.

Adult↗
PubMed1991

Endoscopic ultrasound examination of the upper gastrointestinal tract using a curved-array transducer. A preliminary report.

Endoscopic ultrasound examination (EUS) of the upper gastrointestinal (GI) tract for the assessment of mural and extramural pathology has attracted growing international interest in recent years. Since February 1989, EUS has been performed on selected patients in our institution using a new Picker-Pentax fiber-optic ultrasound (US) gastroscope. The instrument consists of a forward-view fiber-optic gastroscope with a 5-MHz curved-array linear US transducer mounted directly behind the lens. The scanning plane lies in the long axis of the scope. Based on in vitro US examinations and EUS of 118 patients over an 18-month period, our preliminary experience with the instrument is described. Using EUS, various lesions in the esophageal wall as well as in the gastric and duodenal walls can be visualized. Furthermore, organs and structures outside the GI tract can be seen, and lesions such as enlarged lymph nodes in the mediastinum and abdomen; solid and cystic masses in the liver, pancreas and retroperitoneum; arterial aneurysms; esophageal varices; and gall stones and calcifications can be demonstrated. The 5-MHz transducer does not provide very detailed information on the GI wall. The direction of the ultrasound scanning planes is difficult to define, as the transducer cannot be seen through the optic lens. The method demands great expertise in endoscopy and ultrasound. Indications for EUS have not been definitively established. Evaluation of the diagnostic accuracy of this technique requires further controlled studies. We believe that EUS using a curved-array linear transducer will provide significant diagnostic information of clinical relevance to gastroenterology.

Aged↗