Biomedical subjects
L Demling
Publications and source records attributed to L Demling.
Intragastric infrared photography in conjunction with infrared absorption angiography.
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Mechanical lithotripsy of common bile duct stones.
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Endoscopy in basic research.
Gastroenterological endoscopy has stimulated research in a number of ways. New optical developments culminating in the glass fibre and the video endoscope, were necessary stages in the construction of highly sophisticated instruments. These advanced instruments made research possible and also stimulated it. Quite a few methods were made applicable to the gastrointestinal tract only with the aid of endoscopes. For this purpose, they first had to be carefully studied and then modified. Here, mention might be made of the taking of biopsies for histological work-up, X-ray procedures, diagnostic ultrasound, Doppler ultrasonography, operative endoscopy and laser beams. Developments have ensured that endoscopy did not remain restricted merely to its role as an optical diagnostic procedure capable only of visualizing the surfaces of internal organs. In numerous areas, operative endoscopy has now replaced the classical surgical procedure, and further developments may be expected in this field.
Combined therapy of malignant stenoses of the upper gastrointestinal tract by means of laser beam and bougienage.
Eighteen patients with malignant inoperable stenoses of the upper digestive tract were treated with a combination of laser (neodymium-YAG) coagulation and bougienage. Following treatment, 14 out of 18 patients (78%) were able to eat solid food again; the width of the lumen was greater than 11 mm in every case. Between 1 and 5 laser sessions (median 3.5) and between 1 and 2 (median 1) bougienages were required; per session, between 1,017 and 9,096 joules (median 3,362) were required, and a total of between 4,770 and 36,244 joules (median 8,763) were utilized per patient treated. To date, 6 patients remain free of dysphagia (at between 3 and 24 weeks), 1 patient has in the meantime been submitted to surgery. In 7 patients, recurrent stenosis occurred, which was again treated with the laser (3) or with an endoscopically implanted prosthetic tube (4). In 4 patients, the result was unsatisfactory. By way of major complications, merely one perforation occurred. We conclude that the combined use of laser coagulation and bougienage represents an effective and largely complication-free palliative treatment for malignant stenoses in the upper digestive tract.
Endoscopic findings in a case of Kaposi's sarcoma with involvement of the large and small bowel.
A case of Kaposi's sarcoma in underlying acquired immunodeficiency syndrome (AIDS) with involvement of the colon and the terminal ileum is presented. The endoscopic and histological findings are described and the technical and clinical aspects of the results discussed.
Video endoscopy. Fundamentals and problems.
The video system represents a new endoscopic technique with major advantages, some of which point the way into the future. This system permits a large number of persons to participate directly in the examination. Documentation is more comprehensive and more reliable, and pathological processes can be observed with the aid of video tape recordings. It is to be expected that the optical elements of the video endoscope will become smaller, while the instruments will become longer. Since there is no loss of light with these endoscopes, it would appear possible that they will make the entire small bowel accessible to inspection. Compared with conventional standards, the colour quality on the video monitor screen, in particular in the red range, and of the video photograph still leaves something to be desired. User-friendly equipment provided with an automatic colour adaption facility, is required. The good thing about the future is, of course, that it comes slowly - and this applies to video endoscopy, too. Since July, 1984, our department has been acquiring experience with the video endoscope manufactured by the firm of Welch Allyn, New York, and, in the meantime, we have examined 97 patients with this system, 80 in the upper, 17 in the lower gastrointestinal tract. The heart of the video endoscope is a light-sensitive microprocessor silicon chip, roughly 4 X 4 mm in size, which acts like a miniature television camera. Properly, it is termed a charge coupled device chip (CCD chip). Utilizing the crystalline structure of the silicon chip, and its property for thermal oxidation, such electronic components as diodes, capacitors and resistors are integrated onto it.(ABSTRACT TRUNCATED AT 250 WORDS)
Follow-up of patients with colorectal adenomas.
With the aim of establishing suitable follow-up intervals, we examined the probability for the recurrence of relevant adenomas in the colorectum. A total of 592 adenoma patients in whom colonoscopy up to the caecum had reliably excluded relevant findings, were admitted to the study. Relevant findings were considered to be 1) colorectal carcinoma, 2) an adenoma with severe cellular atypia, 3) an adenoma of at least 5 mm in diameter, 4) a histologically unclassified polyp of at least 5 mm in diameter. We were able to show that the use of a dose-effect relationship is statistically justified for the follow-up results of the 592 patients. Thus, the probability for renewed relevant findings at any given time can be computed on the basis of the follow-up results. Renewed relevant findings were presented by 6.0% of patients with single adenomas after 4 years (confidence level 4.8-7.3%), while 5.7% of patients with multiple adenomas had relevant findings after 2 years (confidence level 4.5-7.0%). These follow-up intervals are, thanks to the adequate detection rate, economical and, at the same time, safeguard adenoma patients with a high level of reliability, against cancer of the colorectum.
NMR spectrometric stool fat analysis--a new technique for quantifying steatorrhea and establishing the indication for enzyme replacement in chronic pancreatitis.
In 93 patients with known exocrine pancreatic function (secretin-pancreozymin test), NMR spectrometry and chloroform-methanol extraction of quantitatively collected, homogenized and lyophilized stools provided significantly correlated results with respect to stool fat concentration (r = 0.872) and total stool fat excretion/day (r = 0.983). In 83% of 24 patients with total stool fat excretion/day of more than 15 g (chloroform-methanol extraction), the indication for enzyme replacement was also established by stool fat concentrations of more than 35% determined by NMR spectrometry, irrespective of whether stool fat was measured in total stools or in 3 consecutive unhomogenized samples. In the remaining (17%) patients total stool fat excretion/day was only slightly elevated (16-21 g). Interestingly, in only 58% of patients actually needing enzyme replacement, did the secretin-pancreozymin test reveal a reduction of stimulated enzyme secretion to below 15% of the lower normal limit. The results indicate that NMR spectrometry of lyophilized samples of 3 consecutive unhomogenized stools is suitable for stool fat quantitation and for establishing the indication for enzyme replacement in chronic pancreatitis.
Initial experience with the new electronic endoscope.
With the introduction of an electronic sensor attached to the tip of a flexible endoscope, which functions in the manner of a television camera, new dimensions have been opened up for endoscopy. First reports on the clinical application of this new method have been presented at congresses held recently. We, too, were given the opportunity of trying out the prototype of an electronic colonoscope in four patients. This is a brief report of our findings.
Lithotripsy in the common bile duct using ultrasound. Preliminary in vitro experiments.
In patients with an increased surgical risk, common bile duct stones can be removed with the aid of endoscopic papillotomy. Most stones are either passed spontaneously, or can be drawn out with the Dormia basket. Excessively large stones can first be smashed with the mechanical lithotripter. Some 20% of the stones presenting are, however, too hard to be smashed in this way. A technique was accordingly developed for smashing such bile duct stones using ultrasound. A prerequisite for this technique was the development of an acoustic wave guide that would conduct ultrasound energy even when bent. With this procedure, it will soon be possible to destroy bile duct stones in situ.
[Biliary pancreatitis--diagnostic and therapeutic possibilities with ERCP and endoscopic papillotomy].
The present retrospective study was undertaken to investigate the value of diagnostic procedures--clinical and biochemical parameters, ultra-sonography and ERCP--and the influence of endoscopic papillotomy on the course of biliary pancreatitis in 22 patients. A further 22 patients with alcoholic pancreatitis served as a control group. In the 22 patients with biliary pancreatitis, the case history pointed to biliary disease in 14 cases; in contrast to the patients with alcoholic pancreatitis, in none of these patients did excessive alcohol consumption precede the disease. Seven out of the 22 patients with biliary pancreatitis, but only 2 out of the 22 cases of alcoholic pancreatitis had a previous cholecystectomy. The pain was localized in the right upper abdomen in 60% of the biliary pancreatitis patients, as compared with only 32% of the patients with alcoholic pancreatitis. The laboratory parameters (serum amylases, SGOT, serum bilirubin and leucocytes) did not permit any differentiation between biliary and alcoholic pancreatitis. With respect to the biliary genesis of pancreatitis, the sensitivity of the ultrasound examination was about 68%. The endoscopic detection of a so-called "stone papilla", spontaneous suprapapillary bilio-duodenal fistula, or a blood-tinged papilla, was evidence in favour of a biliary cause of the pancreatitis. In 12 patients, the stones has passed spontaneously; 10 patients were submitted to endoscopic papillotomy for bile duct stones detected by ERCP, and the stones were removed in 9/10 patients. A worsening of the clinical picture by ERCP was not observed in any of the patients. The course of serum amylases, leucocytes and pain in the papillotomied patients corresponded to that in patients with spontaneous stone passage. The results of the present study show that endoscopic papillotomy with stone extraction represents, in most patients with biliary pancreatitis, a possibility for causal therapy, avoiding an emergency surgical intervention. In demonstrated cholecystolithiasis, cholecystectomy can be planned as an elective procedure.
Gastric aminopyrine clearance--an obsolete technique?
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A new glucose electrode for tissue measurements.
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Initial results of transgastric endoscopic ultrasonography in comparison with external ultrasound.
Endoscopic ultrasonography was developed in an attempt to utilize the improved resolution of small-parts ultrasonography also in the investigation of organs located deep within the body as opposed to at the surface. A further expected advantage vis-à-vis external ultrasonography was the avoidance of the frequently obstructing air. In an initial study of 40 patients with a variety of different diseases of the upper abdomen, we were indeed able to utilize the advantages described, with the result that diagnostic information was obtained that neither external ultrasound nor endoscopy was able to provide. A limitation of endoscopic ultrasonography is the fact that the "path" of the transducer is predetermined by the course of the gastrointestinal tract. A further difficulty is the anatomic orientation. To combat this latter problem, our working group has under X-ray control, established standard position for the ultrasound endoscope.
[Changes in therapy of duodenal ulcers. The European Gastro-Club 1983 discusses new pathophysiologic and epidemiologic data referring to drug and surgical therapy].
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[Mechanical destruction of common bile duct calculi].
After endoscopic papillotomy freedom from stone in the choledochal duct can be achieved in about 90% of cases. Either there is a spontaneous passage of concrements or they can be extracted with a basket. But in 10% the stones are so large or are so disproportionate to the size of the distal choledochal duct, that they cannot be removed by conventional means. Mechanical lithotripsy is an easy and simply learned alternative to electro-hydraulic lithotripsy or intraductal gall-stone dissolution for non-surgical removal of large concrements. So far the method has been successful in 18 of 20 patients. Average size of the bile-duct concrements was 27.3 mm with a mean distal choledochal diameter of 10.4 mm. In four patients the stone fragments were passed spontaneously, in 14 they were removed either with the lithotripter itself or the basket. Mechanical lithotripsy is thus an important addition to the non-surgical treatment of gall-stones.