Search

Combined endoscopic and surgical intervention was undertaken in 728 consecutive patients with primary or secondary gallstone disease. In primary gallstone disease the combined treatment resulted in a residual stone rate of 1.28%, and 1.09% for the total group. Intervention on the lower biliary tract (n = 228) resulted in a morbidity rate of 7.4% and a mortality rate of 1.3%. The corresponding figures with purely endoscopic procedures were 1.2 and 0.0%, respectively. Intraoperatively manometrically tested papillary function after endoscopic papillotomy (EPT) revealed no significant difference from normal. In patients with proven biliary pancreatitis the mortality rate after EPT was 2.9%. These results indicate that routine inclusion of endoscopy into the surgical treatment concept for gallstone disease can improve the overall results.

We present a unique data acquisition system designed to read out signals from the MADPET-II small animal LSO-APD PET tomograph. The scanner consists of 36 independent detector modules arranged in a dual-radial layer ring (phi 71 mm). Each module contains a 4 x 8 array of optically isolated, 2 x 2 mm LSO crystals, coupled one-to-one to a 32 channel APD. To take full advantage of the detector geometry, signals from each crystal are individually processed without any data reduction. This is realized using custom designed mixed-signal ASICs for analogue signal processing, and FPGAs to control the digitization of analogue signals and subsequent multiplexing. Analogue to digital converters (ADCs) digitize the signal peak height, time to digital converters (TDCs) time stamp each event relative to a system clock and two 32 bit words containing the energy, time and position information for each singles event are multiplexed through three FIFO stages before being written to disk via gigabit Ethernet. Every singles event is processed and stored in list-mode format, and coincidences are sorted post-acquisition in software. The 1152 channel data acquisition system was designed to be able to handle sustained data rates of up to 11 520 000 cps without loss (10 000 cps/channel). The timing resolution of the TDC was measured to be 1 ns FWHM. In addition to describing the data acquisition system, performance measurements made using a 128-channel detector prototype will be presented.

MADPET-II is a novel high-resolution, high-sensitivity three-dimensional lutetium oxyorthosilicate avalanche photodiode small animal PET scanner with a unique detector design and readout that creates new possibilities for data processing and analysis. The scanner consists of a ring of dual-layer detector modules (O71 mm), each containing a 4/spl times/8 array of 2/spl times/2/spl times/6mm/sup 3/ (front) and 2/spl times/2/spl times/8 mm/sup 3/ (back) LSO crystals that are each optically isolated and coupled one-to-one to a monolithic 4/spl times/8 APD array. Signals from each channel are individually processed using fully-integrated 16-channel, low noise, charge sensitive preamplifiers and custom integrated electronics that include a four channel shaping amplifier, peak detector and non-delay line CFD. Analog-to-digital converters and time-to-digital converters digitise the pulse height and time-stamp each event, and data are stored exclusively in list mode format. Two 32-channel detector blocks were tested in a coincidence and in a dual-layer configuration. Coincidences were sorted post-acquisition in software, allowing for maximum flexibility in the data processing. Monte Carlo simulations have calculated the system spatial resolution to be 1.1 mm FWHM. Average energy resolution for a single detector block ranged from 20.2% FWHM to 23.9% FWHM. System pulse height linearity was measured, and all channels responded with R/sup 2/>0.9988 (Pearson correlation coefficient). Intrinsic uniformity for each detector block ranged from 2.0% to 4.8% (400 keV threshold). Overall system timing resolution was measured to be 10.2 ns FWHM, with individual LORs having time resolutions as low as 4.5 ns FWHM.

A test has been carried out to evaluate the prospects to readout scintillating fibers by avalanche photodiodes (APD). A BICRON BCF-12 fiber of 2×2 mm 2 cross-section and 10, respectively 35 cm length has been used. As lightsensor, a Hamamatsu 1×1 mm 2 APD was coupled to the fiber. Electrons from a 106 Ru source, passing the fiber, produce about 100 photoelectrons. Prospects for other geometries and possible improvements are discussed.

To take advantage of the compactness of avalanche photodiode (APD) arrays, low-noise power-efficient fast charge-sensitive preamplifier chips with differential current drivers have been developed. A 16-channel and a single-channel version are available. The chips were adapted for low-capacitance 4/spl times/8 APD arrays produced by Hamamatsu, Japan. A mixed junction field-effect transistor (JFET)-CMOS production process yielded high-quality integrated JFETs for the input stage of the amplifier's folded cascade. Thus, the 1/f-noise corner is kept at 4 kHz. The JFET has a transconductance of 11 mS at a drain current of 3 mA. The serial noise of the input transistor was found to be 0.8 nV//spl radic/(Hz). The signal rise time of the driver outputs is 20 ns. The rms noise of the preamplifier was found to be 480 e/sup -/ with a 25 e/sup -//pF noise slope for a shaping time of 50 ns. The serial input noise of the preamplifier is about 1.4 nV//spl radic/(Hz) from 200 kHz up to 40 MHz, and the 1/f-noise corner is at 70 kHz. The power consumption is 30 mW per preamplifier, including the differential driver. The linearity is better than 1.3% over 48 dB dynamic range. For the 16-channel chip, the channel-to-channel gain variation is less than 3.5%. Performance similar to photomultiplier tubes can be achieved with APDs in combination with this integrated preamplifier chip.

Avalanche photodiodes (APDs) offer new design options for high-resolution positron emission tomography (PET) detectors. The goal of this study was the design of a very compact PET detector module with two layers. For this purpose, new monolithic arrays of 4/spl times/8 densely packed APDs (each with a 1.6/spl times/1.6 mm/sup 2/ sensitive area) were developed and evaluated for their suitability to read out 32 small (2/spl times/2/spl times/6 mm/sup 3/) lutetium oxyorthosilicate (LSO) crystals. The gain of the APDs was about 100, its standard deviation within an array was less than 12%. The average dark current was less than 45 nA per pixel, and the detector capacitance was about 12 pF. Energy resolution was 15% for gamma-rays with 511 keV. The time resolution was 2.5 ns (full-width at half-maximum). A high-reflectivity foil was used to hold all 32 individual crystals in a matrix. This matrix was glued directly on the APD array. The light crosstalk between the channels was only 7.9%. Together with a specially developed 16-channel low-noise JFET-CMOS preamplifier chip, a compact front-end detector module was built. The monolithic APD arrays proved to be stable and may, in combination with lutetium oxyorthosilicate (LSO) crystals, facilitate the design of various detector geometries, such as panels or multilayer modules.

The observation of high energy cosmic gamma rays with an energy threshold of 15 GeV using the proposed MAGIC ground based air imaging Cherenkov telescope requires the development of new low noise fast preamplifiers for the camera photosensors. The speed and noise performance of a transimpedance preamplifier that resolves the multi photoelectron peaks from a hybrid photomultiplier with a peaking time below 7 ns is presented. The new front-end circuit is designed with RF low noise bipolar transistors and provides fast output pulses that allow for fast trigger settings.

The liquid argon calorimeter of the H 1 detector presently taking data at the HERA ep collider at DESY, Hamburg, is described. The main physics requirements and the most salient design features relevant to this calorimeter are given. The aim to have smooth and hermetic calorimetric coverage over the polar angular range 4° ≤ θ ≤ 154° is achieved by a single liquid argon cryostat containing calorimeter stacks structured in wheels and octants for easy handling. The absorber materials used are lead in the electromagnetic part and stainless steel in the hadronic part. The read-out system is pipelined to reduce the dead time induced by the high trigger rate expected at the HERA collider where consecutive bunches are separated in time by 96 ns. The main elements of the calorimeter, such as the cryostat, with its associated cryogenics, the stack modules, the read-out, calibration and trigger electronics as well as the data acquisition system are described. Performance results from data taken in calibration runs with full size H 1 calorimeter stacks at a CERN test beam, as well as results from data collected with the complete H 1 detector using cosmic rays during the initial phase of ep operations are presented. The observed energy resolutions and linearities are well in agreement with the requirements.

Inbred animals (Lewis rats) were used to investigate the regeneration of autologously implanted splenic tissue at intra-omental and subcutaneous sites. Quantitative immunohistology with monoclonal antibodies against lymphocytes and macrophages was performed to analyse the cell density of red pulp (RP), periarteriolar lymphoid sheath (PALS), marginal zone (MZ) and follicle, 7-180 days after transplantation. Antigenic, allogeneic and mitogenic stimulation and Northern blotting were also performed. Transplant groups differed from spleen only in the reduced size of PALS; however, quantitative analysis demonstrated subtle differences between spleen and transplants. The cell density of B-cells and ED-1+ macrophages was reduced in the RP, Tsupp/cyt-cells were decreased and B-cells increased in PALS, and B-cells and Thelper-cells reduced in the MZ. No differences could be detected between the transplant groups. Flow-cytometric analysis of cell suspensions from spleen and transplants revealed a reduction of T-cells (OX-19+), MHC-I and transferrin-receptor-bearing cells in both transplant groups, and a decrease in the number of Thelper-cells and ED-3+ macrophages in subcutaneous transplants. Both transplant groups were defective regarding the allogeneic and pokeweed mitogen response. Aberration of the lipopolysaccharide response was restricted to subcutaneous transplants, which additionally showed abnormal expression of interferon-gamma, interleukin-5 and interleukin-6 mRNA. Thus, subtle alterations of the newly developed microenvironment and/or lymphocyte-homing may influence the regeneration of splenic tissue; the implantation site may represent an important parameter in functional reorganisation.

We are presently building an array of angle integrating air Cherenkov counters for the study of VHE and UHE cosmic rays. The new array will be sensitive to extended air showers of energies > 5 × 1013 meV and of zenith angles up to 35°. The determination of the incident shower direction will be performed by fast timing measurements with an angular resolution of 0.5–5 mrad. The Cherenkov counters will allow us to obtain information on the shower energy and structure higher up in the atmosphere. The array will be combined with the existing HEGRA scintillation counter matrix on La Palma. The combination of the Cherenkov data and the data from the ground level scintillator matrix will provide a powerful tool for γ/hadron discrimination. We expect to achieve hadron rejection ratios of > 103 when adding the proposed muon detectors, thereby making possible the detection of the diffuse γ radiation presumed to be coming predominantly from the galactic plane.

The ability of splenic tissue to regenerate after avascular transplantation at different target tissues is well documented but the capacity of splenic transplants to compensate the loss of spleen and the influence of the implantation site on the functional development of replants are still discussed contradictory, because little is known about specific functions of the transplants. Therefore, we investigated splenic implants in rats at different states of development and in different target tissues (intraomental and subcutaneous implantation site).

A data acquisition system has been developed to read out signals from the MADPET-II small animal LSO-AFD PET scanner. The scanner consists of 36 independent detector modules arranged in a dual-radial layer ring (/spl Phi/ 71 mm). Each module contains a 4/spl times/8 array of optically isolated, 2/spl times/2 mm LSO crystals, coupled one-to-one to a 32 channel APD. To take full advantage of the detector geometry, signals from each crystal are individually processed without any data reduction. This is realised using custom designed mixed-signal ASICs for analogue signal processing, and KPGAs to control the digitisation of analogue signals and subsequent multiplexing. A DCs digitise the signal peak height, TDCs time stamp each event relative to a system clock, and two 32 bit words containing the energy, time and position information for each event are multiplexed through three FIFO stages before being written to disk via gigabit Ethernet. Even' singles event is processed and stored in list mode format, and coincidences are sorted post-acquisition in software. A 128-channel prototype system is currently in operation. System pulse height linearity and count rate performance were measured by supplying test inputs to the pre-amplifier. All channels responded linearly with R/sup 2/>0.9988 over a 6:1 input dynamic range, and input pulses were transmitted to disk with 0% data loss up to 45,000 cps/channel. The timing resolution of the TDC was measured to be 1 ns FWHM.

MADPET-II is a small animal PET scanner currently under development, that provides individual channel readout for each one of its 1152 LSO-APD electronic channels. In order for such a large number of channels to be processed individually, the analog signal processing electronics are fully integrated into single monolithic chips. Each chip contains a differential receiver, a shaping amplifier, a peak hold detector and a non-delay line constant fraction discriminator. In the CFD the delay line has been replaced by a high pass CR circuit, which can result in comparable timing resolution. The performance of the chip has been tested by studying the output signals of the shaper, the peak detector and the CFD. The bias currents have been adjusted so as to maximize the signal to noise ratio and to minimize the walk of the CFD output (trigger). The response of the peak detector to different input signal amplitudes is linear (R2 = 0.9961). The walk performance of the CFD can be adjusted by changing the R component of the CR high pass filter, and it can be minimized to approximately 2 nsec over a 5:1 amplitude input dynamic range. An improved version of the chip will have a different value of the C component of the CR high pass circuit. Its timing performance is expected to improve and be less sensitive to variations in changes to the R component of the high pass filter. From simulations, the walk is expected to be approximately 200ps over a 5:1 amplitude dynamic range.

Ground-based Atmospheric Air Cherenkov Telescopes (ACTs) are successfully used to observe very high energy (VHE) gamma rays from celestial objects. The light of the night sky (LONS) is a strong background for these telescopes. The gamma ray pulses being very short, an ultra-fast read-out of an ACT can minimize the influence of the LONS. This allows one to lower the so-called tail cuts of the shower image and the analysis energy threshold. It could also help to suppress other unwanted backgrounds. Fast 'flash' analog-to-digital converters (FADCs) with GSamples/s are available commercially; they are, however, very expensive and power consuming. Here we present a novel technique of Fiber-Optic Multiplexing which uses a single 2 GSamples/s FADC to digitize 16 read-out channels consecutively. The analog signals are delayed by using optical fibers. The multiplexed (MUX) FADC read-out reduces the cost by about 85% compared to using one ultra-fast FADC per read-out channel. Two prototype multiplexers, each digitizing data from 16 channels, were built and tested. The ultra-fast read-out system will be described and the test results will be reported. The new system will be implemented for the read-out of the 17m diameter MAGIC telescope camera., 31 pages, 26 figures, to be published in NIM A

One of the future goals is to install a PET detector in a magnetic field for a combined PET/MRT device. Thus, in this study the influence of a 9.4 Tesla magnetic field on a small scintillation detector with avalanche photodiode (APD) readout was tested. The detector, comprising a 3.7/spl times/3.7/spl times/12.0 mm/sup 3/ lutetium oxyorthosilicate (LSO) crystal coupled to the 3 mm O active surface of an APD was exposed to 511 keV gamma rays from a /sup 22/Na source. The energy resolution at room temperature was 14.4% (FWHM). Measurements of gain and energy resolution were performed outside and in the center of a homogeneous magnetic field of 9.4 Tesla. Both, the gain and energy resolution were unaffected by the magnetic field being either parallel or orthogonal to the electrical field of the APD. These results prove the potential of using APDs in a combined PET/MRT imaging system.

The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large-volume TPCs for tracking and particle identification via dE/dx. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions.

Technical aspects of the three major components of the H1 detector at the electron-proton storage ring HERA are described. This paper covers the detector status up to the end of 1994 when a major upgrading of some of its elements was undertaken. A description of the other elements of the detector and some performance figures from luminosity runs at HERA during 1993 and 1994 are given in a paper previously published in this journal.

General aspects of the H1 detector at the electron-proton storage ring HERA as well as technical descriptions of the magnet, luminosity system, trigger, slow-control, data acquisition and off-line data handling are given. The three major components of the detector, the tracking, calorimeter and muon detectors, will be described in a forthcoming article. The present paper describes the detector that was used from 1992 to the end of 1994. After this a major upgrade of some components was undertaken. Some performance figures from luminosity runs at HERA during 1993 and 1994 are given.

Praoperative diagnostische Methoden haben eine unterschiedliche Aussagekraft bezuglich einer zu erwartenden Malignitat von Schilddrusenknoten. Die klinische Untersuchung ist sehr zuverlassig, wenn ein Karzinom schon zur Organuberschreitung bzw. Infiltration umgebender Halsstrukturen gefuhrt hat. Bezuglich der Fruhdiagnose oder der Aussage eines Karzinomverdachtes ist sie vielfach nutzlos [6].

Maligne Schilddrusentumoren stellen etwa 90% aller endokrinen Tumoren (Ramacciotti 1984). Zwar sind nur etwa 1% aller malignen Tumoren Schilddru-senmalignome, andererScits kann jeder Knoten im Schilddrusenbereich durch ein Malignom bedingt Scin. In Osterreich liegt die Zahl der Neuerkrankungen bei 3,6 pro 100000 Einwohner pro Jahr.

This paper presents the results of a combined endoscopic-surgical approach with management of acute biliary pancreatitis in 91 patients. The diagnosis was always made by means of endoscopic-retrograde cholangiography. Papillary or bile duct stones, or unmistakable signs of previous stone passage, and in exceptional cases flow obstruction due to preiampullary diverticuli were considered criteria for a positive diagnosis. All 91 patients were subjected to endoscopic sphincterotomy with/without stone extraction subsequent to the diagnostic cholangiogram. Endoscopic intervention was performed as soon as possible after admission to hospital, but by 48 hours at the latest. Cholecystectomy was carried out in all patients who were free of risk factors and without previous cholecystectomy, during the disease-free interval. The complication rate of this combined endoscopic-surgical approach amounted to 10.9%; the mortality rate was 3.3%. The achieved results suggest that endoscopic sphincterotomy with stone extraction in the acute phase of biliary pancreatitis is the method of choice in order to interrupt the process of this disease. In combination with the final surgical treatment of gallstone disease by cholecystectomy to avoid recurrences, the prognosis of acute biliary pancreatitis can be significantly improved by using this combined endoscopic-surgical management.

In anatomical preparations performed during autopsy we developed a well-defined approach for the identification of the recurrent laryngeal nerve during surgery on the thyroid gland. The principle of this concept is to visualize the nerve near the branching of the inferior thyroid artery, where it shows a 30 degree angle to the trachea in a direction running from caudal lateral to cranial medial and lies in front of, behind, or between the branches of the artery. This preparation mode has been prospectively performed in 100 patients undergoing thyroid surgery. In 159 (= 97.6%) sides of the neck out of 163 we identified the nerve at the typical site. The topographical relation of the recurrent nerve to the inferior thyroid artery revealed the following differences for the right and left side of the neck: On the right side the nerve was found to be behind in 48%, in front in 33% and between the branches of the artery in 15% of cases. In contrast, on the left side the nerve was found to be dorsal in 53%, ventral in 23% and between the branches in 23%. Of 163 nerves at risk we observed primary nerve palsy in 2 cases (1.2%), and a definitive palsy rate of 0.6% at the 3-month follow-up. In conclusion, we recommend the described approach for the identification of the recurrent laryngeal nerve during thyroid surgery whenever complete mobilisation of the thyroid lobe (e.g. thyroidectomy, lobectomy, resection of retrotracheal adenomas) is necessary.

The effect of human pericardial patch plastic for reconstruction of iatrogenic common bile duct stenosis was investigated in experiments performed in pigs. All patches (n = 8) were overgrown with immature biliary epithelium detectable on light and electron microscopy within 6 weeks. No restenosis nor any fistula developed during this observation period. Liver function tests, especially bilirubin, were not suitable parameters for the detection of biliary obstruction (preoperative value 0.38 +/- 0.09 mg/dl; 1 week after subtotal stenosis 3.36 +/- 1.53 mg/dl; 2 weeks after subtotal stenosis 1.49 +/- 0.62 mg/dl; 3 weeks after subtotal stenosis 0.50 +/- 0.27 mg/dl; 6 weeks after pericardial patch plastic 0.33 +/- 0.05 mg/dl, mean +/- SD. Ultrasonographic measurement of the common bile duct diameter was the diagnostic method of choice. Preoperative dimension 4.5 +/- 0.5 mm; 1 week after subtotal stenosis 8.5 +/- 2.0 mm; 2 weeks after subtotal stenosis 10.5 +/- 1.8 mm; 3 weeks after subtotal stenosis 14.0 +/- 3.6 mm; 6 weeks after pericardial patch plastic 9.0 +/- 1.6 mm, mean +/- SD.

A total of 50 patients--37 female and 13 male--with an average age of 50 +/- 27 years (23-86 years), suffering from rim-calcified gallbladder stones, underwent extracorporeal shock-wave lithotripsy (ESWL), using an ultrasound-guided overhead module of Lithostar Plus (Siemens Company). The total number of stones was 87, with an average diameter of 16 +/- 7 (7-38) mm. 29 patients had a solitary stone, 13 had two and 8 patients three or more stones. All patients received adjunct medication of 10 mg/kg body weight chenodeoxycholic and ursodeoxycholic acid 14 days prior to ESWL as a single bedtime dose. An average number of 5,300 +/- 2,200 shock waves (1,200-15,000) was applied for stone disintegration. The corresponding energy amounted to 750 bar. 29 patients needed one, 21 two or more treatments. After ESWL a variety of clinical abnormalities was observed: flank pain (15%), transient microhaematuria (33%) and transient macrohaematuria (2%). Subsequent to ESWL 5 patients suffered from complications such as biliary obstruction 3 weeks to 9 months after treatment and had to undergo ERCP. Three times endoscopic papillotomy was performed to remove stones from the common bile duct. Up to now 4 patients have undergone cholecystectomy: acute cholecystitis (n = 3), recurrent colicky pain (n = 1). 20 patients have been followed up over a 12-month period; 12 of them are completely free of stones and fragments.

Trotz exakter Operationstechniken und Unterbindung der groseren Lymphbahnen treten nach Lymphknotendissektionen im Rahmen von Tumorbehandlungen (Melanome, Mammakarzinome, Weichteilsarkome etc.), aber auch nach gefaschirurgischen Eingriffen gehauft Lymphfisteln in der Axilla und der Inguinalregion auf. Die Inzidenz wird in der Literatur zwischen 13 und 43% angegeben (4, 5). Diese Lymphfisteln stellen zwar meist keine schwerwiegenden, aber aufgrund der langen Behandlungsdauer und der erhohten Infektionsgefahr lastige Komplikationen fur Patienten und Operateur dar (3, 6).

The implantation of splenic tissue at different implantation sites (intraomental and subcutaneous) into one animal (Lewis rats) results in the development of splenic nodules at both sites. In a quantitative immunohistological analysis of splenic compartments such as red pulp (RP), periarteriolar lymphoid sheaths (PALS), marginal zone (MZ) and follicles (F) the T-cell reduction was related to the T(helper) cells in the MZ and T(supp/cyt) cells in the PALS. In contrast, the cell density of B cells and ED-1+ macrophages in the PALS and T(supp/cyt) cells in the MZ was increased. Significant differences between the implantation sites were restricted to CD5+ cells (thymocytes and T cells) in the MZ and OX-33+ cells (B cells with LCAB antigen) in the PALS. The reorganisation of the compartments of subcutaneous implants showed a delay of one week as compared with omental ones. Functional assays like haemolytic plaque assay, mitogen stimulation and mixed lymphocyte assay elicited an analogous delay of the functional maturation of IgM-positive B cells, a reduced proliferation of both transplant groups after pokeweed mitogen (PWM) stimulation, a decreased response after lipopolysaccharide (LPS) stimulation in solely subcutaneous replants and no differences concerning the mitogens concanavalin A (ConA) and phytohaemagglutinin (PHA). Both transplant groups showed a significantly reduced allogeneic response. The results of the functional analysis and the abnormal mRNA expression of Il-5, Il-6 (Interleukin 5 and 6), GMCSF (Granulocyte-Macrophage-Colony-Stimulation-Factor) and IFN-gamma (Interferon gamma) in subcutaneous replants indicate subtle molecular alterations (independent of a spleen-like immunoarchitecture) at this site.(ABSTRACT TRUNCATED AT 250 WORDS)

Out of 284 patients with acute pancreatitis 73 (26%) had pancreas necrosis. Of these 73 cases 43 patients with infected pancreas necrosis were treated surgically, whereas conservative treatment proved successful in the remaining 30 cases with so-called sterile necrosis. Our interdisciplinary treatment combined delayed surgery for the better demarcation of the necrotic tissue, with extended intensive care therapy and epigastral laparostomy; through this laparostomy surgical revision with necrosectomy and peritoneal lavage was performed daily for 15 (+/- 6) days, necessitating long-term artificial respiration for an average of 15 (4/168) days. The mortality rate in the 43 patients with infected pancreas necrosis amounted to 16.2% (n = 7); none of the patients with sterile necrosis died. In cases of multiple organ failure the mortality rate was significantly higher (30%) than with failure of only one organ system (4.3%). The mortality rate in all cases with pancreas necrosis (n = 73) amounted therefore to 9.5%. Serious complications of laparostomy occurred in 28% (n = 12) of the 43 patients, whereby 8 of these cases were gastrointestinal fistulae, with a fatal outcome in one patient. The overall mortality rate in the total group of 284 patients with acute pancreatitis was 2.8%.

300 Pat. mit Cholecystohthiasis wurden einer ESWL zugefuhrt. 47 Pat. hatten einen Gesamtsteindurchmesser >3cm, 50 Pat. Steine mit Ringverkalkungen. Bisher traten bei 15 Pat. (5%) endoskop. beherrschbare Komplikationen auf: Pankreatitis 4 (1%), bihare Obstruktion 11 (3,7%).4 dieser Pat. hatten eine primare Steingrose >3 cm, 5 Pat. Kalksteine. Weitere 12 Pat. (4%) wurden cholecystektomiert:ak. Cholecystitits 5 (1,6%), rezidiv., heftige Koliken 5 (1,6%), keine Steindesintegration 2 (0,6%). 8 dieser Pat. hatten einen Gesamtsteindurchmesser 3 cm oder Kalksteine. Die erweiterte ESWL-Indikation fuhrte zu einem signifikanten Anstieg endoskop. (2,9% > 9,2%) als auch chir. (1,9 >8,2%) Folgeeingriffe.

Die im Gefolge von chronischen Lebererkrankungen mit portosystemischer CoUateral-kreislaufentwicklung sowie nach portosystemischen Shuntoperationen auftretenden Encephalopathien sind in ihrer Pathogenese bislang ungeklart. Neben dem Einflus verschiedener potentiell cerebrotoxischer Substanzen und Storungen im Aminosaurenmetabolismus scheinen auch Veranderungen von klassischen sowie das Auftreten von sogenannten falschen Neurotransmittersubstanzen eine Rolle in der Atiopathogenese dieses neuropsychiatrischen Syndroms zu spielen [2]. So konnten in experimentellen Studien Veranderungen im Metabolismus von Dopamin, Serotonin, Gammaaminobuttersaure und z.T. auch von Noradrenalin nach Anlegen portocavaler Shunts nachgewiesen werden [3]. Mit der Entdeckung von Substance P 1931 wurde eine intensive Forschungstatigkeit gastrointestinaler Hormone eingeleitet. Bald wurde erkannt, das viele von den in den folgenden Jahren entdeckten Peptiden nicht nur im Gastrointestinaltrakt, sondern vor allem auch im peripheren und zentralen Nervensystem vorkommen und dort eine Rolle als Neurotransmittoren und Modulatoren aufweisen [4]. Obwohl die physiologische Wirkung dieser auch als “regulatory peptides” bezeichneten Substanzen in weiten Bereichen noch unbekannt ist, scheinen sie neben zahlreichen endokrinen Einflussen auf die Homeostase auch eine Bedeutung bei neurophysiologischen Vorgangen wie Gedachtnis- und Lernleistungen, Verhaltensweisen und Emotionalitat zu besitzen. In einer tierexperimentellen Studie haben wir den Einflus eines portocavalen Shunts, einem anerkannten Modell fur eine HE, auf die Gewebskon-zentrationen verschiedener Neuropeptide und biogener Amine im zentralen Nervensystem (ZNS) der Ratte untersucht.

Die Hemithyreoidektomie stellt beim suspekten kalten Solitarknoten die bessere Alternative gegenuber partiellen Resektionen dar, da bei definitivem Malignitatsnachweis die Notwendigkeit eines erneuten Eingreifens auf derselben Seite entfallt (Senkung des Komplikationsrisikos). Bei grosen and bei dorsal gelegenen Knoten wird durch Lobektomie das Belassen von dorsalen Knotenresten vermieden (Senkung des Rezidivrisikos, Senkung der Rate persistierender Autonomien). Ihre Durchfuhrung erfordert spezifische operative Erfahrung and Routine in der erhaltenden Darstellung von N. recurrens and Nebenschilddrusen. Unter dieser Voraussetzung ist sie gegenuber den partiell resezierenden Verfahren nicht mit einem erhohten Komplikationsrisiko verbunden.

Highly malignant thyroid tumours are frequently diagnosed only at an advanced stage where radical resection is no longer feasible. By the wide application of fine needle aspiration biopsy as a diagnostic tool in nodular thyroid diseases occasionally early stages of these tumours can be diagnosed. Despite early detection in 23% of our patients with anaplastic carcinomas and sarcomas of the thyroid gland and subsequent radical resection an improvement in the long-term outcome was not achieved. In contrast, thyroidectomy and appropriate oncologial therapy may result in long-term survival of patients with early stages of thyroid lymphomas.

Der zytologische Befund „III” beinhaltet verschiedene Veranderungen bei Struma nodosa, die zu Zellatypien fuhren. Hyperthyreose und Strumitis zeigen durch erhohten Zellumsatz bzw. Entzandung ein zytologisches Bild, das schwer von differenzierten Karzinomen zu unterscheiden ist. In unserer Studie an 231 Patienten mit Punktat „III”, zeigte sich, das bei einer Kombination mit Hyperthyreose bzw. Thyroiditis nur in einem Prozent ein Malignom vorlag. Bei euthyreoter Struma nodosa und Punktat „III” war die Malignomrate so hoch (26%), das eine primare Lobektomie gerechtfertigt ist.

A suspicious preoperative cytology (= class "III") may be the result of various disorders of the thyroid presenting with cell atypia. For example hyperthyroidism or thyroiditis can show a cytological aspect, mimicing a differentiated carcinoma. Our study, comprising 231 patients with cytology "III" revealed a low malignancy rate (1%) in cases of concurrent hyperthyroidism or thyreoiditis. In contrast, 26% of the patients presenting with euthyroid nodular goiter and cytology "III" had a malignant histology such patients should be treated by primary lobectomy.

The widely differing mortality rates of severe gastroduodenal hemorrhage reported in the literature (10-30%), are due to very inhomogeneous patient groups. The purpose of this study was therefore to rank various clinical and endoscopical factors by giving them points from 0 to 6, both to establish comparable groups and to use them as prognostic parameters for a potential fatality rate. One hundred and ninety-three patients with severe gastroduodenal bleeding, verified at emergency gastroscopy immediately after admission, were admitted to this prospective study. The statistical assessment of the prognosis for these 8 factors revealed a linear correlation between increasing score and mortality rate for the following risk factors: patient age, activity and intensity of hemorrhage, type and number of associated illnesses, various therapeutic procedures. Only the type of the source and the site of the hemorrhage did not correlate well. By adding up the points of all risk factors for every patient we calculated the overall score and established a correlation to the mortality rate: A definite statistical correlation was demonstrated between increasing score and fatal outcome. If a patient with a score of less than 20 points did survive in 100%, the mortality rate increased linearly to 83.3% in patients with a score of 40 points. Using this scoring system it is possible to establish comparable groups of patients - which seems indispensable for a critical examination of various therapeutic procedures. Furthermore, this score can serve as a predictor of the probability of a fatal outcome shortly after patient admission.

We present first results using a photodiode readout for BGO and Nal(Tl) crystals. The measurements indicate that photodiodes might replace photomultiplier tubes in electromagnetic calorimetry. Using commercial photodiodes, a noise equivalent r.m.s. error of 1–2 MeV has been observed. Limitations and possible future improvements are discussed.

This project was undertaken to evaluate in a prospective fashion the effects of selective preoperative endoscopic-retrograde cholangiography and stone extraction (ERCP-ST EXTR) on the results of biliary tract surgery. Over a 6-year period, 728 patients with primary or secondary biliary tract disease were admitted to the First Surgical Department, landeskrankenanstalten, Salzburg, Austria. If, based on preoperative screening, the possibility of common bile duct stones (CBDS) existed, the patients were subjected to ERCP-ST EXTR. Two to 4 days later, these patients underwent a simple cholecystectomy with intraoperative cholangiogram and functional manometry. Evaluation criteria for this study were morbidity, mortality, and retained stone (RST) rates. The overall complication rate for the entire series was 6%. In patients who underwent operative common duct stone removal (n = 78), the complication rate amounted to 21.8%. The rate was reduced to 2.1% by ERCP-ST EXTR. The RST rate was likewise reduced from 2.2% to 0.5% by ERCP-ST EXTR. Mortality in patients with CBDS fell from 3.8% to 1% through the use of this method. In those patients with secondary stones who were treated by ERCP-ST EXTR only, morbidity was 2%, the RST rate was 0%, and mortality was 0%. It is concluded that selective ERCP-ST EXTR, followed by simple cholecystectomy, is a suitable treatment protocol and that this approach may reduce complication and mortality rates.

In einer experimentellen Studie an 66 Kaninchen verglichen wir zwei Arten der Transplantatzubereitung: 1. 4–5 Milzstucke von 1 mm Dicke steigenden Gewichts (5–800 mg) wurden am parietalen Peritoneum angenaht. 2. Milzhomogenate wurden ebenfalls in steigender Menge (5–800 mg) in 4–5 praformierte Taschen des parietalen Peritoneums eingebracht. Das regenerierte Milzgewebe wurde nach Laparotomie der Tiere in verschiedenen postoperativen Abstanden bis maximal 42 Tage postoperativ entnommen, gewogen und histologisch untersucht. Dabei zeigt sich eine lineare Beziehung von End- und Anfangsgewichten. Diese Korrelation gilt aber nur bis zu einer oberen Gewichtsgrenze von 200 mg bei den Homogenaten und 300 mg bei den Stucken. Insgesamt regenerierten Homogenate besser als Stucke.

Der ruckblick auf 40 jahre strumarezi-divprophylaxe zeigt in erster Linie, wie wichtig die organisierte und konsequente betreuung der patienten auch Jahre nach der Strumaresektion ist. Unser derzeitiges konzept der rezidivprophylaxe sieht eine lebenslange medikation mit 50 μg L-Thyroxin bei euthyreoten strumen ab dem 6. postoperativen tag, bei den autonomen adenomen ab dem 1. postoperativen Monat und bei den hyperthyreoten Strumen ab dem 3. postoperativen monat vor.

The study deals with the immunological capacity and perfusion rate of splenic grafts in pigs after autologous transplantation into the omentum majus. 12 months after operation the weight and relative blood flow of the regenerated splenic tissue were clearly reduced. The number of antibody forming cells in the grafts was only slightly decreased compared to the normal spleen, whereas the autotransplants could balance a serum-IgM-deficiency, observed due to splenectomy, 4 months after grafting. Furthermore the mitogenic stimulation of T- and B-lymphocytes showed different proliferation rates for the autotransplants compared to the spleen.

Several clinical and laboratory studies have demonstrated the risk of sepsis in connection with encapsulated bacteria. The importance of clearing these organisms by the spleen is now well accepted. In contrast, the present work deals with the clearance of non-encapsulated gram-negative bacteria (Escherichia coli). The animals used for the experiments (a heterogeneous population of rabbits) were divided into a control group, a splenectomized group, and an autotransplanted group. The histological examination of the splenic transplants revealed typical splenic tissue including lymphatic follicles with germinal activity 42 days after transplantation. For estimation of the clearance capacity different amounts of bacteria were injected i.v. into the rabbits, and colony-forming bacterial cells in the blood were counted at certain intervals. In the control group no bacteria could be detected in the blood after 7 min. All animals of the splenectomized and autotransplanted groups showed a remarkable decrease in clearance efficiency (no bacteria in the blood after 19 min). No difference in the clearance kinetics could be shown between splenectomized and autotransplanted animals. Measuring the uptake of bacterial cells into different organs elicited low incorporation in the spleen as compared to non-immunocompetent organs, but no difference between normal spleen and splenic replants. However, saturation with E. coli cells reached higher limits in the normal spleen than in autotransplants. The immunologic capacity with respect to IgM-producing lymphocytes was measured by the hemolytic plaque assay. The results showed a severe malfunction of the autotransplants as compared to the normal spleen (only 2% of the activity of the control group). Vaccination against E. coli increased the clearance efficiency in all three groups. The data presented in this paper point out that several functions of the spleen cannot be carried out by autotransplants. The reasons, therefore, may be limited transplant mass and/or decreased specific functions.

Intraoperative manometry was performed in 771 patients undergoing cholecystectomy with (n = 158) and without (n = 613) interventions on the common bile duct and papilla. The method measures the resting pressure (RP) and pressure increase (PI) after injection of 1 ml NaCl/s as well as the time (TR) used for return to the initial pressure, using a Statham transducer. All values are recorded and statistically processed by the two-tailed t test. All three manometric parameters (RP, PI and TR) were statistically different (p less than or equal to 0.0001) between patients with and without alterations of the bile duct and papilla respectively. There was also a clear difference (p = 0.0001) of the TR (which is an indirect measure of the bile flow) between patients with stenosis of papilla (n = 55) and those who showed calculi in the bile duct (n = 103). In a further study we could demonstrate that histopathological changes of the papilla (specimen was taken during transduodenal papilloplasty because of isolated papilla stenosis) led to a prolonged TR, whereas TR in patients with negative histology was decreased. The sensitivity and specifity of this manometric method was very high, 92.4 and 98.6% respectively. This method of manometry enables to obtain precise data about pressure and flow in the bile duct uninfluenced by subjective reading errors in a simple and reproducible way. In our opinion it should complete other intraoperative diagnostic methods during cholecystectomy, particularly as manometry was the only method which led to the correct final diagnosis in 2% of 771 patients.

Der PFI wird aus dem Quotienten der mittleren und maximalen Frequenzverschiebung eines gepulsten Dopplersignals berechnet. Er korreliert mit dem peripheren Stromungswiderstand. Der Normalbereich wurde an Nierenarterien 60 gesunder Probanden ermittelt. 163 konsekutive Duplex-Untersuchungen wurden in Transplantatarterien von 58 Patienten durchgefuhrt. Der PFI wurde mit klinischen Parametern, Isotopennephrografie und ggf. einer Transplantatbiopsie verglichen. Eine Abstosung wurde in 85% richtig zutreffend (Sensitivitat) und in 81% richtig nicht zutreffend (Spezifitat) erkannt. Der PFI erlaubt damit, nicht invasiv zwischen Nierenversagen und Abstosung zu unterscheiden.

Palliative surgical treatment of malignant oesophago-gastric strictures has been disappointing. Resections in an advanced tumor stage are heroic interventions with a high mortality rate. Alimentary fistulas do not release from annoying saliva regurgitation but unnecessarily mutilate the terminal patient. The positioning of a tube under endoscopic control into the constricting neoplasma has the following advantages: 1. deglutition and saliva drainage are restored; 2. morbidity- and mortality rate is low; 3. duration of hospitalization is brief (1-2 days).