Dopamine-dependent diastolic dysfunction in moderate hypothermia

We designed an experimental animal study to study the effects of dopamine (DA) on diastolic function in hypothermia. DA was applied at five incremental infusion rates in 6 sheep during normothermia and moderate hypothermia (29 degrees C). Left ventricular end-diastolic pressure (LVEDP) was increased during hypothermia as compared with normothermia at all doses of DA. Contraction and relaxation velocity were changed only slightly during hypothermia; during normothermia, both velocities were markedly increased. The pronounced hemodynamic effect observed during hypothermia was further intensified by occurrence of aftercontractions, which disappeared at very high DA doses. These paradoxic results were considered the result of hypothermia-induced reduction in active transport mechanisms responsible for regulation of the cytoplasmic CA2+ concentration. The generally reduced inotropic effect of DA, the risk of paradoxic reactions, and the occurrence of aftercontractions must be taken into account when emergency drugs are administered clinically during hypothermia.

[Dynamic blood volume determination using the body transport function]

This paper describes a dynamic blood volume determination which is faster and more accurate than the classic method. The new method determines blood volume by means of the product of the mean transit time of the circulation and the cardiac output. The mean transit time is calculated from the body transport function. To examine the precision of the dynamic method the blood volume of 24 patients was determined in both the dynamic and the classical way, using radioactively labelled erythrocytes. The comparison of the two methods resulted in a correlation coefficient of r = 0.77. The dynamic method of blood volume determination will be helpful especially in risk patients to accurately determine the quantities of fluids to be administered.

Dynamische Blutvolumenbestimmung mit Hilfe der Körpertransportfunktion

In dieser Arbeit wird die dynamische Blutvolumenbestimmung beschrieben, die gegenüber der klassischen Blutvolumenbestimmung schneller und genauer ist. Das neue Verfahren beruht auf der Bestimmung des Blutvolumens mit Hilfe des Produkts aus mittlerer Kreislauftransitzeit (Umlaufzeit des Blutes) und Herzzeitvolumen. Die mittlere Kreislauftransitzeit wird aus der Körper-Transportfunktion berechnet. Um die Genauigkeit der dynamischen Blutvolumenbestimmung zu überprüfen, wurden bei 24 Patienten mit Hilfe von radioaktiv markierten Erythrozyten das Blutvolumen sowohl klassisch als auch dynamisch bestimmt. Der Vergleich der beiden Methoden ergab einen guten Korrelationskoeffizienten von r = 0,77. In Zukunft kann die dynamische Blutvolumenbestimmung besonders bei Risikopatienten hilfreich sein, um den Flüssigkeitsbedarf schnell und genau zu überwachen.

Need for active left-ventricular decompression during percutaneous cardiopulmonary support in cardiac arrest

During ventricular fibrillation, myocardial hemodynamic and metabolic effects of percutaneous cardiopulmonary support (PCPS) were analyzed in 11 adult sheep (body weight 77-112 kg). During supported fibrillation, an abrupt increase in left-ventricular pressures with alignment to aortic pressures was observed in 2 animals, which was probably due to spontaneous aortic regurgitation, and resulted in deterioration of coronary perfusion. In 9 animals, left-ventricular pressures rose from 22.9 +/- 4.9 to 31.2 +/- 7.9 mm Hg elevating left ventricular wall stress from 16,750 +/- 8,745 to 28,835 +/- 8,892 dyn/cm2 after 10 min of PCPS-supported fibrillation (mean flow rate 4.5 +/- 0.7 liters/min). Simultaneously, myocardial perfusion pressures decreased from an average of 32.4 +/- 11.7 to 22.3 +/- 9.4 mm Hg and myocardial lactate release was observed. Additional transapical LV venting using a 9-Fr catheter led to a decrease in both LV pressure (to 25.7 +/- 5.3 mm Hg) and wall stress (to 20,612 +/- 7,499 dyn/cm2). Left-ventricular decompression decreased myocardial oxygen consumption (from 5.3 +/- 1.4 to 4.8 +/- 0.9 ml/min.100 g), and reduced myocardial lactate release, which indicates myocardial protection. Protective effects were most pronounced using 12-Fr-, and 21-Fr-venting cannulas (with 21 Fr: decrease in myocardial oxygen consumption to 2.7 +/- 0.6 ml/min.100 g, and reversal of myocardial lactate release to lactate uptake during fibrillation). Conclusions. Hemodynamic and metabolic data clearly demonstrate the deleterious effects of PCPS to the unvented left ventricle during cardiac arrest. The results emphasize the need for active left-ventricular decompression during PCPS in ventricular fibrillation.

Simulation of arterial drug concentration after intravenous application

The aim of this study was to develop a widely applicable model for circulatory indicator dispersion which could describe the pharmacokinetics of early drug distribution. The model assumes that the substance is injected into the right atrium and measured in the aorta. The dilution curve results from the dispersion and recirculation of the indicator in the body. The concentration time curve in the aorta, r, can be described as r = c0 + g* r, where g is the transport function of the body and c0 is the concentration time course, which is measured for the first time in the aorta. If the body transport function is known, then the aortic dilution curve of a drug can be predicted for different elimination rates and injection times. The site of interest can be chosen arbitrarily, i.e. the concentration of inflow into the kidney or any other organ can be described.

In situ extracorporeal shockwave lithotripsy of distal ureteral stones: parameters for therapeutic success

Between January and December 1989, 123 patients with distal ureteral stones were treated with in situ extracorporeal shockwave lithotripsy (ESWL) using a modified HM3 Dornier lithotriptor. One hundred and three patients (83.7%) were stone-free, 20 patients (16.3%) had small residual stones (< 1 mm2) that passed spontaneously. In situ ESWL treatment alone was successful in 88 of the 103 stone-free patients (85.4%). Fifty-six (54.4%) needed 1 ESWL session, 26 (25.2%) needed 2 ESWL sessions. Nineteen of the 123 patients (15.4%) needed auxiliary endourological measures. The results of ESWL treatment were correlated to pretherapeutically identified parameters such as stone size, radiopacity, outer contour, shape, inner structure, biochemical analysis of the stones and grade of dilatation of the upper urinary tract. The results prove that size (> or = 75 mm2), radiopacity and grade of dilatation have a direct correlation to the difficulty to disintegrate ureteral stones.

Left-ventricular unloading by transvalvular axial flow pumping in experimental cardiogenic shock and during regional myocardial ischemia

The efficacy of the transfemoral left-ventricular assist device Hemopump (HP; 21 Fr outer diameter) was examined in experiments with adult sheep in two different models of cardiogenic shock (tachycardia shock; ischemia shock), and during ventricular fibrillation. During tachycardia (high frequency pacing-induced; n = 14), HP assist led to a significant increase in cardiac output (from 2.2 to 2.8 liters/min), mean aortic pressure (from 47.6 to 65.6 mmHg), and myocardial perfusion pressure (from 25.5 to 59.0 mmHg). Simultaneously, a normalization of body oxygen-uptake (from 1.4 to 2.5 ml/min.kg), a decrease in myocardial oxygen consumption (from 6.1 to 4.8 ml/min.100 g), and a normalization of myocardial lactate metabolism were observed during HP assist. During regional myocardial ischemia (PTCA balloon occlusion of the proximal LAD (3.5 min; n = 12), HP assist led to significant decrease in LV end-diastolic pressure (from 21.1 to 12.1 mmHg), and increase in diastolic aortic pressure (from 58 to 67 mmHg) resulting in significant increase in coronary perfusion pressure. In the early reperfusion period, myocardial release of both lactate and potassium was significantly lowered with HP assist. During ventricular fibrillation (induced by electrical stimulation; n = 9), HP flow rates decreased from 2.5 (after 10 min) to 2.1 liters/min (after 30 min). Mean aortic pressures simultaneously decreased from 64.0 to 54.6 mmHg. Perfusion conditions were sufficient for maintenance of aerobic myocardial metabolism, but were borderline for peripheral circulation. Our hemodynamic and metabolic data demonstrate beneficial effects of cardiac assist with the Hemopump 21 Fr in both tachycardia-induced severe cardiogenic shock and during acute regional myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Single-shot measurement of ultraviolet and visible femtosecond pulses using the optical Kerr effect

We present a method that allows the single-shot measurement of femtosecond pulses in the ultraviolet as well as the visible spectral regions. The method is based on the optical Kerr shutter technique, and it provides the third-order intensity correlation function.

[The use of the RACE technique for quantitative flow measurements. Evaluation using a clinically relevant flow model]

A phantom has been designed for measuring flow velocities; using pipes of specified diameter and selectable pulse rates, flow rates varying from 0-250 cm/s can be determined. The measurements are made in a superconductive magnet with a field strength of 1.5 Tesla, employing a RACE technique. The reference technique was electromagnetic flow measurement. There was good linear correlation between the electromagnetic and the MRT results with a correlation coefficient of 0.98. It is necessary in the first place to estimate flow speed; if flow velocity is unknown initially, there is no correlation. Hence, in everyday use erroneous results may be obtained, particularly since one cannot always demonstrate vessels in all parts of the body without superimposition. Further clinical studies are required in various vascular territories to evaluate the usefulness of the RACE technique for flow measurements.

Influence of pH management on hemodynamics and metabolism in moderate hypothermia

In moderate hypothermia, three different concepts of pH management have been described to date: pH-stat, alpha-stat, and alkalinity. In our study these pH strategies were compared in adult sheep, with animals serving as their own controls for direct comparability. Hemodynamic parameters, such as mean aortic pressure (from 109 +/- 12 to 72 +/- 23 mm Hg), cardiac output (from 5.55 +/- 1.25 to 4.5 +/- 0.82 L/min), and systemic oxygen consumption (from 3.73 +/- 0.8 to 1.81 +/- 0.4 ml/kg/min), decreased significantly with alpha-stat at 28 degrees C from values for normothermia. No marked or even significant differences were found among the three pH strategies in any value, with the exception of body oxygen consumption. The difference of 2% between pH-stat and alpha-stat, at 0.06 ml oxygen/kg/min, was significant (p < or = 0.05), however of no practical relevance because hypothermia itself caused a decrease of nearly 52%. With regard to myocardial parameters, pH-stat impaired myocardial function compared with both alpha-stat and alkalinity. At nearly identical mean aortic pressures and cardiac outputs, myocardial oxygen consumption reached the highest level in pH-stat (7.65 ml oxygen/100 gm/min; alpha-stat, 6.76 ml oxygen/100 gm/min; p < or = 0.05). Myocardial efficiency thus decreased from 21% (alpha-stat) to 17% (pH-stat). No evident changes in hemodynamic and metabolic values were found for alkalinity vs alpha-stat. The best response to continuously infused epinephrine, however, was found with alkalinity. According to our data there was an impairment of myocardial function without any evident further reduction in body metabolism with pH-stat vs alpha-stat. There were, however, no marked metabolic or hemodynamic differences between alkalinity and alpha-stat, with the exception of a better preservation of sensitivity to adrenergic stimuli with alkalinity.

Calculation of body transport function

A new model for simulation of recirculation has been developed which describes the measured concentration-time course of a drug in the aorta. It is based on repetitive convolution of the injected input dilution curve with a body transport function plus the input dilution curve. If the basic shape of a body transport function, i.e. such as log-normal distribution, is known, it is possible to calculate the parameters of this function with a non-linear least-squares procedure from measured tracer dilution data. In the present investigation this algorithm is used to estimate the body transport function for experimental data, obtained in two experiments with sheep. Once the body transport function is known, the formula can be used to describe the dispersion of a drug. Intravascular concentration time curves at different places in the body can also be predicted or the blood volume can be estimated.

Efficiency of the left ventricle assist device Hemopump in cardiac fibrillation

We have examined in sheep the efficiency of the Hemopump during ventricular fibrillation. Circulatory arrest was induced by electrical stimulation and maintained for 30 min. Haemodynamic measurements were recorded continuously and blood samples were taken before, during and after fibrillation to determine total body and myocardial metabolic activity. All hearts were defibrillated successfully after 30 min of fibrillation. During fibrillation, the Hemopump sustained a mean arterial pressure of about 60 mm Hg with a blood flow rate of about 2.3 litre min-1. These perfusion conditions were sufficient for maintenance of aerobic myocardial metabolism, but with a borderline circulatory supply to the total organism.

Early or delayed onset of cyclosporine by sequential immunosuppression?

In a prospective randomized trial, 57 renal transplant patients (group A) received a sequential course of 14 days conventional immunosuppression (anti-lymphocyte globulin (ALG), azathioprine and steroids) and cyclosporine and steroids thereafter, while 57 patients (group B) received the conventional immunosuppression for 2 days followed by cyclosporine and steroids. In group A, ALG was tolerated for a mean of 7.8 days while, in group B, conventional therapy had to be changed to cyclosporine therapy after a mean of 2.1 days due to ALG intolerance. Patient survival rates 1 and 2 years after transplantation were 95% and 92% in group A and 96% and 92% in group B, and graft survival rates were 79% and 79% in group A and 89% and 82% in group B. In group A, the dialysis frequency in the second, third and fourth weeks after transplantation was significantly higher than in group B. Serum creatinine 1 year post-transplant showed no significant difference between the two groups.

Protective effects of the Hemopump left ventricular assist device in experimental cardiogenic shock

The efficacy of the new cable-driven rotating left ventricular assist device Hemopump in cardiogenic shock was examined in experiments with adult sheep (n = 14; body weight 50-71 kg). Shock was induced by high frequency ventricular pacing. Aortic, pulmonary, central venous and left ventricular pressures as well as electromagnetic measurements of coronary blood flow were recorded continuously; cardiac output was measured by thermodilution technique. Blood samples for determination of oxygen content, electrolytes and lactate were taken under control conditions, in shock, and during pump intervention at different levels of pump speed. Vascular resistance, total body and myocardial oxygen consumption as well as myocardial uptake and release of lactate were calculated. High frequency pacing led to a significant decrease in cardiac output (from 3.8 +/- 0.8 to 2.2 +/- 1.6 l/min), mean aortic pressure (89.1 +/- 14.4 to 47.6 +/- 7.2 mmHg), and total body oxygen consumption (2.6 +/- 0.3 to 1.4 +/- 0.7 ml/min per kg), as well as myocardial release of lactate (arterial coronary-venous difference of lactate: 0.27 +/- 0.26 to -0.32 +/- 0.72 mmol/l). Hemopump assist in this condition resulted in a significant increase in cardiac output (to 2.8 +/- 0.6 l/min), mean aortic pressure (to 65.6 +/- 13.9 mmHg), and myocardial perfusion pressure (from 25.5 +/- 11.0 to 59.0 +/- 14.7), and led to nearly normal total body oxygen consumption (2.5 +/- 0.7 ml/min per kg), a decrease in myocardial oxygen consumption (from 6.1 +/- 2.1 in shock, to 4.8 +/- 1.7 ml/min per 100 g), and to normal arterial coronary-venous difference of lactate (0.24 +/- 0.26 mmol/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Healing of bladder wall after contact and non-contact Nd-YAG laser photocoagulation. Experimental study in piglets

The healing process of the bladder wall after contact and non-contact Nd-YAG laser irradiation was studied in 18 piglets. The animals were sacrificed 1 h, and 2, 5 and 14 days after photocoagulation. The lesions were examined histologically by light and scanning electron microscopy. Immunohistochemical stains were prepared for visualization of lactate dehydrogenase. Perforation of the bladder wall was found in 2 cases where a contact probe was used (15 W/2 s). A crater in the bladder wall resulting from tissue ablation was seen in all cases immediately after contact laser irradiation. Photocoagulation using a non-contact laser led to white necrosis in the bladder wall. Minimal tissue ablation was evident at the highest power setting used (35 W/2 s). After 2 days inflammation around the lesion was marked. Inflammation with fibroblasts invading the damaged area was seen 5 days after photocoagulation. Fourteen days after photocoagulation minor scar formation was evident beneath the histologically normal epithelium. It is concluded that lesions caused by contact or non-contact Nd-YAG laser photocoagulation will heal within 2 weeks with minor scar formation.

Photodynamic therapy of gastrointestinal tumors: a review

Photodynamic therapy (PDT) is a new modality of cancer treatment. It consists of intravenously injecting a patient with a photosensitizing agent and, when this agent has accumulated in tumor cells, decomposing it by exposure to red light produced by an argon dye laser. Toxic compounds produced in this reaction then destroy the malignant cells, while normal tissue is not significantly affected. Most clinical experience with PDT has been gained in the treatment of lung cancer, cancer of the urinary bladder and malignancies of the head and neck region. In gastroenterology, esophageal, gastric and colonic tumors have clinically been treated with PDT. This paper is to review the current use of PDT in the treatment of gastrointestinal tumors.

Donor conditions and graft survival--a retrospective study

In a retrospective study (one centre) the influence of donor and recipient factors were evaluated (n = 308). Head injury as the cause of death and anastomotic time less than 35 min were associated with a significantly better graft survival rate (P < 0.05). Although some of the donor factors influence graft survival, a stricter selection of grafts is not advisable, firstly because fewer kidneys would then be offered, and secondly because even comparatively bad graft survival rates are still better than dialysis.

Laser-induced hyperthermia: comparison of two different methods

The effectiveness of two different techniques of laser-induced hyperthermia was analyzed in healthy piglet livers. Hyperthermia was produced using a continuous-wave Nd:YAG laser with both a contact sapphire probe and a bare quartz fibre. In both methods the tip was inserted into the liver, and the temperature 1 cm from the tip was raised and held between 42 degrees C and 44 degrees C for 600 seconds. Specimens were taken 0, 7 and 14 days after the treatment. The tissue effects of 36 treatment sites were analysed using standard van Gieson's method. In addition, a histochemical method for demonstrating lactate dehydrogenase activity was employed to show damage not observable by routine methods. No statistically significant difference in the extent of the treatment sites at d 0 and after 7 days was seen when comparing the two laser methods. After 2 weeks, the diameter of the lesion with the bare fibre was significantly larger (3,7 mm with both analysing methods) than by using the contact probe (2,6 with LDH demonstration; P < 0.01 and 2.1 mm with van Gieson's staining; P < 0.001). It can be concluded that the simple fibre tip seems more effective in causing tissue necrosis than the sapphire tip.

Pancreatic resection versus peritoneal lavage in acute necrotizing pancreatitis. A prospective randomized trial

Twenty-one patients with acute fulminant alcoholic pancreatitis were randomly allocated to either pancreatic resection group (11 patients) or nonoperative peritoneal lavage group (10 patients). Only patients under 50 years were included in the study to minimize the role of other severe disease. These patients represented the most severe cases of acute pancreatitis at our Department, constituting only 2% of all patients with acute pancreatitis during this period. The diagnosis was based on clinical symptoms and on signs indicating severely impaired systemic organ functions. All patients underwent contrast-enhanced computed tomography (CT), which showed contrast enhancement below 30 Hounsfield units. In the operated cases, the diagnosis of necrotizing pancreatitis was verified histologically. All patients with conservative treatment had dark brown fluid at peritoneal puncture. There was a difference (nonsignificant) in mortality (3/11 and 1/10, respectively), complication rate, or in the need of reoperations between the groups. Nonoperative peritoneal lavage was followed with shorter treatment at the intensive care unit (16.2 versus 25.9 days, respectively). The hospital stay also was significantly shorter in the nonoperative group (44.3 versus 56.1 days). The results indicate that intensive conservative treatment is justified as an initial therapy even in the most severe cases of acute pancreatitis.

Renal function after partial nephrectomy with the Nd-YAG laser. Experimental study in piglets

Twelve partial nephrectomies were performed in 12 piglets using either the combination (contact and non-contact) Nd:YAG laser technique or a steel scalpel. Additional haemostasis was attempted with ligatures. The renal artery was not clamped and renal cooling was not attempted. Total nephrectomy was performed on the contralateral side. Serum creatinine and urea levels were measured, and 99mTc-DTPA renography was performed pre-operatively and 1 and 2 weeks post-operatively. One week post-operatively the mean serum creatinine level was 35% higher than the pre-operative level in the laser group and 30% higher in the steel scalpel group. Two weeks post-operatively the respective differences were 34 and 24%. The mean urea level 1 week after operation was 50% higher than the pre-operative level in the laser group and 17% higher in the steel scalpel group. Two weeks post-operatively the respective differences were 38% in the laser group and 20% in the steel scalpel group. The mean DTPA disappearance rate was 34% lower 1 week after operation in the laser group and 23% lower in the steel scalpel group when compared with the preoperative state. Two weeks post-operatively the respective changes were 48 and 25%. These data indicate that there is no significant difference in renal function when the Nd: YAG combination laser technique is used in partial nephrectomy as compared with the steel scapel.

Myocardial support and protection during regional myocardial ischemia using the Hemopump assist device

A study was designed to quantify the influence of the Hemopump on myocardial metabolism in regional myocardial ischemias induced by repetitive balloon-occlusions (3.5 minutes) of the LAD in 12 sheep (b.w. 49-61 kg). In order to make immediate comparisons and obtain paired-couples, ischemias were carried out with and without the Hemopump in operation. An energetic unloading of the left ventricle was achieved by the Hemopump already under preocclusion conditions, reducing myocardial O2-consumption from 7.52 to 5.98 ml/min/100 g LV (= 20%) as well as lowering the LVEDP from 13.3 to 9.8 mmHg (p less than or equal to 0.01). During ischemia a clear increase of LVEDP (13.3 to 21.0 mmHg) occurs, which was prevented in the group with Hemopump-assist (9.8 to 12.1 mmHg). Combined with a sustained higher diastolic aortic pressure, a better myocardial perfusion pressure resulted. Energetic unloading and improvement of perfusion conditions might be the cause of the significantly lowered release of lactate and potassium. Due to theses fibrillation (n = 3) only occurred during occlusions without Hemopump-support. In summary, a significant reduction of the ischemic burden on the myocardium was found. Thus the Hemopump could be of benefit to patients who fail to be weaned from CPB or who are suffering from instable cardiovascular performance.

Application of a CCD linear array camera in the quantification of tissue staining: NBT detection in ischaemic myocardium

A method was developed to quantify the intensity of tissue staining using a CCD (charge-coupled device) camera. Reflection spectra of NBT-stained (nitro-blue tetrazolium-stained) and unstained myocardium were recorded via fibre optics coupled to a CCD camera, connected to a microcomputer. The calculation of the intensity of staining was based on evaluation of the NBT-related changes of the reflectance spectrum. In each of six anaesthetized sheep, global ischaemia was induced by cross-clamping of the aorta. The hearts were removed and incubated at 35 degrees C. At predetermined times two sections of ventricular myocardium were taken, one of which was then stained with NBT, the other being left unstained. Evaluation of the reflectance spectra from stained sections during the first phase of ischaemia showed a slight loss of NBT colour intensity followed by a more rapid loss of staining until the values of the unstained sections were reached. In contrast to the conventional visual evaluation, the method provides quantitative data on the intensity of staining, and allows use of the NBT technique for statistical evaluation of what happens over time, and the regional distribution of ischaemic injury of tissue. This method may also be applied to other staining techniques.

Diagnostic evaluation and aggressive surgical approach in bleeding pseudoaneurysms associated with pancreatic pseudocysts

Hemorrhage is an uncommon but serious complication of pancreatic pseudocysts. When gastrointestinal bleeding or intra-abdominal hemorrhage is associated with a pancreatic pseudocyst and the usual sources of bleeding are not detected by endoscopy, the rupture of a pseudoaneurysm inside the pseudocyst should be suspected. We present 13 cases, 11 associated with chronic and 2 with late complications after acute necrotizing pancreatitis. On the basis of sonographic findings, bleeding site was suspected in 8 of 11 patients (73%). Computed tomography (CT) was performed on 10, and bleeding was suspected in 8 (80%). The pseudoaneurysm itself was detected by CT in one and by ultrasonography in none. Visceral angiography was performed on five patients, and the pseudoaneurysm was evident in all. External drainage with arterial ligation was done as a primary operation in five patients; four of them later underwent pancreatic resection because of rebleeding. In eight cases pancreatic resection was the initial operation; none of these patients continued to bleed or needed reoperation because of the same pseudoaneurysm. There were no intraoperative deaths, but one patient died postoperatively. Aggressive diagnostic evaluation and surgical approach are associated with a reduction in mortality and morbidity in this serious complication of pancreatic pseudocysts.

Nd: YAG contact laser in partial nephrectomy. An experimental study in piglets

The Nd: YAG contact laser technique with 12 W power output was used in partial nephrectomies in six piglets. Blood loss, total time and number of ligatures needed for haemostasis were compared in six partial nephrectomies performed with a steel scalpel. Mean blood loss was 53 g with the laser and 108 g with the steel scalpel (p less than 0.04). The mean time needed for haemostasis were 9.5 and 16.2 min respectively (p = 0.2) and the average number of ligatures required 1.5 and 8.8, respectively. The mean temperature rise at 5, 10 and 20 mm distance from the resection line was 5.3, 1.2 and 0.3 degrees C, respectively. The use of laser reduced blood loss and shortened the operation time. Further studies are needed concerning renal function after kidney surgery with a laser.

Comparison of endoscopic Nd:YAG laser therapy and oesophageal tube in palliation of oesophagogastric malignancy

The clinical results of 96 patients with upper gastrointestinal malignancy have been evaluated retrospectively. Sixty-nine patients with a mean age of 72 years (35 men and 34 women) were treated with endoscopic laser therapy, and 27 patients with a mean age of 67 years (16 men and 11 women) with insertion of an oesophageal tube. After laser therapy the bulk of the tumour was reduced in 87%, and in 55% clear signs of relieved dysphagia were seen. The insertion of an oesophageal tube was successful in 89%. In the laser group no fatal complications occurred, and the overall complication risk was 8.7%. The 1-year survival in all laser patients was 12%, and in patients with impassable tumour stenosis the survival was 6%. The mortality related to the insertion of an oesophageal tube was 11%, and complications occurred in 48% of the patients. The 1-year survival of the tube group was nil. It is concluded that endoscopic laser therapy and insertion of oesophageal tube are both effective methods in palliation of oesophagogastric malignancy, but the mortality and risk for complications were markedly lower after laser therapy.

Contact Nd:YAG laser potentiates the tumor cell killing effect of hyperthermia

This study was carried out to investigate the effects of Nd:YAG laser-induced hyperthermia on murine F9 embryonal carcinoma cells in vitro using various power settings, temperatures, and exposure times. F9 cells were plated on gelatin-coated dishes, treated on the following day, and cultured overnight. The following day the killing efficiency of the treatments was estimated by staining the dishes or by labeling the cells with 3H-thymidine. A contact Nd:YAG laser with a frosted-end probe was used. After laser treatments at 39 degrees C, no significant changes were observed in the viability of the cells. Laser treatment at 43 degrees C killed F9 cells, and the effect was related to the power setting used. Using 6 W, the quantity of viable cells progressively decreased after 1-, 2-, and 5-min treatments, and no viable cells were found after a 10-min treatment. Using 10 W, approximately 10% of the cells survived a 1-min laser treatment, but all cells were killed after a 2-min treatment. In the control wells, heated in a water bath for up to 40 min, all cells regularly survived at 43 degrees C. There were much less viable cells in those laser-treated wells where the temperature exceeded 44 degrees C than in those where the temperature was kept at 44 degrees C. In conclusion, the tumoricidic effect of hyperthermia can be potentiated by the use of the contact Nd:YAG laser. At a set temperature the cell killing effect of laser treatment is dependent on the power used and the duration of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy and complications of the Nd:YAG laser in partial nephrectomy: experimental study in piglets

Twenty-four partial nephrectomies were performed in 18 piglets using either the combination Nd:YAG laser technique (contact and noncontact) or a steel scalpel. Additional haemostasis was attempted with ligatures. Blood loss, operation time, and number of ligatures were compared in the two treatment groups. Twelve piglets had a two-week follow-up. The mean blood loss with the laser was 72 +/- 10 g and 83 +/- 13 g with the steel scalpel (no significant difference). The resection time until complete haemostasis was 9.8 +/- 0.9 min with the laser and 14.3 +/- 1.3 min with the steel scalpel (p = 0.0076). The number of ligatures needed for complete haemostasis was 2.8 +/- 0.4 with the laser and 7.5 +/- 1.0 with the steel scalpel (p = 0.0051). Three piglets in the steel scalpel group developed urinomas. There were two perirenal abscesses, one in each group. In the steel scalpel group there was one intussusception. In conclusion, it seems that the combination Nd:YAG laser method offers no definitive advantage over the standard technique for partial nephrectomies in the pig.

[Olfactory and gustatory sweating--case report on reflex facial hyperhidrosis]

Localised hyperhidrosis is comparatively rare among the vegetative disorders. A case of pathological gustatory and olfactory sudation is reported, with the sequence of symptoms corresponding to that of the Frey syndrome. Working from the reflex nature of the phenomen, the paper puts forward a model to account for the delayed onset of the manifestation following a peripheral lesion. It is assumed that readjustment of the reflex excitation level takes place according to a modification in peripheral afference, and that a decompensation of the central control mechanisms results in a pathological enhancement of the reflex. The hypothesis of peripheral efferentisl denervation hypersensitivity appears insufficient to account for the delay in manifestation, or even to account for the classic Frey syndrome following an affection of the parotid gland.

[Immediate bypass operation prevents heart infarct in PTCA emergencies]

Between December 1984 and June 30, 1989, we performed PTCAs on 1438 patients. The procedures were performed with strict cardiosurgical standby. In 24 patients (22 X LAD, 2 X RCA), abrupt coronary occlusion necessitated immediate bypass surgery. In 19 cases, abrupt coronary closure occurred during PTCA in the cath lab; in five patients, during the following 24 h on the intermediate care ward. No patient died. Immediate bypass surgery prevented myocardial infarction (MI) in 79.2% of the cases. None of the 19 patients with abrupt coronary closure in the cath lab had a Q-wave myocardial infarction postoperatively. One of these 19 patients had an R-wave reduction (non-Q-MI) and one patient had a new terminally negative T-wave in the postoperative ECG. Two of the five patients with evidence of acute coronary occlusion on the intermediate care ward had small Q-wave MIs and one had a non-Q-wave MI postoperatively. Time of ischemia (defined als time interval between the end of PTCA and the beginning of extracorporal circulation) was 65 +/- 28 min in the former group and 122 +/- 30 min in the latter.

CONCLUSION

Because immediate bypass surgery prevents Q-wave MI after abrupt closure during PTCA, strict temporal and spatial cooperation with the cardiac surgeon is mandatory.

Phospholipase A2 activity and concentration in several body fluids in patients with acute pancreatitis

According to recent studies, phospholipase A2 (PLA2) may be an important factor in the pathogenesis and pathophysiology of acute pancreatitis. Increased serum PLA2 activities and concentrations have been measured in patients with acute pancreatitis. Serum PLA2 activities have been shown to correlate with the severity and prognosis of the disease. To study the different methods of PLA2 determination, we measured the PLA2 activity by means of an isotopic assay method and the concentration by a radioimmunologic method in several body fluids of 52 consecutive patients with acute pancreatitis. PLA2 activity and concentration were detected in all of the patient body fluids. The serum PLA2 activities were 2.5-fold higher (mean +/- SD, 7.6 +/- 6.0) than normal activities, and the concentrations were 9.6-fold higher (mean +/- SD, 41 +/- 88). The enzyme activities and concentrations correlated well in ascites, fluids from the pleural cavity, and peritoneal lavation and poorly in serum, urine, and fluid from pancreatic pseudocyst.

Comparison of somatostatin and vasopressin in bleeding esophageal varices

Somatostatin (ST) and vasopressin (VP) infusions were compared in the treatment of actively bleeding esophageal varices. Fifty-four patients with liver cirrhosis were included in the study. Thirty-two were given ST 4.2 micrograms/min, and 22 patients were given VP 0.4 IU/min for 72 h after endoscopic diagnosis. The role of alcoholic cirrhosis was similar in both groups. Initial control of bleeding was achieved significantly more often (p = 0.0281) when ST was used (84.4%) than during VP treatment (57.1%). Rebleeding occurred in 18.8% and 4.8%, respectively. Side effects of treatment were significantly more common when VP was used than during ST treatment (p = 0.0021). Overall mortality was high in both groups, being 34% in the ST group and 36% in the VP group. ST infusion seems to be more effective and safer than VP in the treatment of acute variceal bleeding. However, the high frequency of rebleeding during ST treatment means that, after primary hemostasis with ST infusion, other methods, such as surgery or sclerotherapy, are needed to prevent the serious complications of rebleeding.

Time-resolved immunofluorometric assays for trypsinogen-1 and 2 in serum reveal preferential elevation of trypsinogen-2 in pancreatitis

We have developed sensitive time-resolved immunofluorometric assays for the two trypsinogen isoenzymes, trypsinogen-1 and trypsinogen-2, which also are called cationic and anionic trypsinogen, respectively. The assays use monoclonal antibodies produced by immunization with tumor-associated trypsinogen that is isolated from mucinous ovarian cyst fluid. In each assay, one antibody is immobilized onto the walls of polystyrene microtiter strip wells and the other is labeled with an europium(III) chelate. The cross-reaction of each trypsinogen isoenzyme in the assay for the other isoenzyme is less than 1%. The detection limits are 0.1 micrograms/L for trypsinogen-1 and 0.3 micrograms/L for trypsinogen-2. In sera of healthy subjects and patients with extrapancreatic disease the concentration of trypsinogen-1 is higher (median, 21 micrograms/L) than that of trypsinogen-2 (median, 17 micrograms/L), but in acute pancreatitis the ratio is reversed. In acute pancreatitis the concentration of trypsinogen-2 is 50-fold higher than in controls, whereas the difference in trypsinogen-1 concentrations is only 15-fold. The corresponding difference in immunoreactive trypsin measured by a commercially available radioimmunoassay was also only 10-fold.

Transfemoral placement of the left ventricular assist device "Hemopump" during mechanical resuscitation

The Hemopump is a new left-ventricular assist device (21 F diameter), which provides up to 3.5 L/min output after placement in the left ventricle via the femoral artery. We describe the first case in which the device was inserted during resuscitation. The patient developed untreatable sustained ventricular tachycardias/fibrillation 40 hours after coronary artery bypass grafting. After prolonged mechanical resuscitation (about 3 hours) as a last resort the Hemopump was inserted and rhythm and hemodynamics stabilized. In the following hours a decrease in aortic pressure pulsatility indicated, effective left ventricular support when the Hemopump was running. For short periods the patient had nonpulsatile aortic pressure wave forms, implying complete pump dependence. In this situation cardiac output was about 3.0 L/min, mean aortic pressure reached nearly 50 mmHg using high dosage of catecholamines. The patient remained pump-dependent and died due to untreatable ventricular fibrillation. There was no significant hemolysis during the 20 hours the Hemopump was running. Autopsy revealed no signs of thrombembolism, but intimal lesions of the A. iliaca and of the abdominal aorta with subsequent thrombus formation were demonstrated. In view of the experimentally proven benefit in cardiogenic shock and problems and risks caused by the insertion, future indications for clinical use of this new device are discussed.

Percutaneous evacuation of abdominal abscesses and fluid collections--aspiration or catheter drainage?

Ninety-three abdominal abscesses and fluid collections (pseudocysts, hematomas and bilomas) in 79 patients were treated under radiological guidance, for a total of 111 procedures (23 needle aspirations (NA) of 17 foci and 88 catheter drainages (CD) of 84 foci). In eight foci both methods were used. Catheter drainage was curative in 65% of abscesses and in 56% of pseudocysts and improved the patients' condition before surgery in another 11% or 10%, respectively. The aim of CD could not be achieved in 24% of the abscesses and in 34% of the pseudocysts. Needle aspiration showed little effect being curative in only 6% and partially beneficial in 24% as all the foci were considered. Complications occurred in 8% of CD:s and in 0% of NA:s. We suggest that radiologically guided CD of abscesses and fluid collections should be the primary therapeutic approach in all cases where this can be performed safely. The therapeutic effect of NA was poor.

[Symptoms of dementia misdiagnosed as psychosocial development disorder in congenital aqueduct stenosis]

The paper describes a case in which symptoms of dementia basing on a chronic psycho-organic syndrome together with congenital aqueduct stenosis were for years erroneously regarded as indicating psychosocial maldevelopment. Emphasis is laid on the need to consider the possibility of a process of dementia, even if maldevelopment of the personality only displays mild neurological symptoms.

Laser for harvesting of the internal mammary artery

In 12 piglets both internal mammary arteries were dissected from the thoracic wall without a surrounding pedicle, using low-current electrocautery for one artery and continuous wave contact Nd:YAG laser (12 W) for the contralateral vessel. Changes in the arterial flow surface were evaluated by scanning electron microscopy immediately after dissection and 2 and 5 days postoperatively. Laser dissection was easier, more accurate and as fast as electrocautery. Moderate to severe degenerative changes and endothelial desquamation were seen in the electrocautery group after dissection, but lesser changes in the laser group. The changes decreased within the next 5 days, but two electrocauterized vessels showed thrombosis at 5 days. Stripping of the internal mammary artery with either method requires great care, and Nd:YAG laser offers a promising alternative to electrocautery in harvesting of that artery as a pedicled graft.

Laser-induced hyperthermia in the treatment of liver tumors

Seven patients with malignant liver tumors were treated with Nd:YAG laser induced hyperthermia. The laserthermia was performed during laparotomy using Nd:YAG laser with contact sapphire probes with power settings of 6 W. The contact tip was placed into the middle of the tumor and the temperature in 1.5-2.0 cm from the middle of the tumor was raised and held between 41C and 45C for ten minutes. One fatal complication appeared caused by an air embolism. In the postoperative fine needle biopsies on third and fifth postoperative day the sytologic finding in the tumor was necrosis. However, in 30% of the samples there was also a suspicion of cancer cells. In the computer tomography four weeks after the treatment there were also signs of necrosis. It seems that selective destruction of malignant liver tumors is possible with contact Nd:YAG laser induced hyperthermia.

Surgical treatment of gastric carcinoma

To investigate changes in the results of treatment of gastric carcinoma, two 10-year periods between 1963 and 1982 with 641 and 630 patients, respectively, were compared. In the two groups, 94 percent and 92 percent of patients were operated on. The operation was considered curative in 200 and 265 patients in Groups 1 and 2, respectively. There was a shift towards more radical operations, with 215 total or subtotal gastrectomies in Group 2 compared with 76 in Group 1, when distal gastric resection was considered radical enough. Despite the increasing number of curative operations and more radical surgery in Group 2, no progress in the 5-year survival rate was noted. Distal and subtotal gastrectomies gave slightly better results than total gastrectomies, but the most important single factor contributing to the long-term survival was cancerous invasion of the serosa. It is concluded that in the past 20 years, the results of surgical treatment of gastric carcinoma have not improved, despite the more advanced diagnostic methods and more radical surgery.

Experimental chronic pancreatitis in the pig

Chronic pancreatitis was induced in 22 piglets by dividing all pancreatic attachments to the duodenum; five sham-operated piglets served as controls. Two piglets died of postoperative complications. The animals were autopsied 2, 4, or 6 weeks postoperatively. All operated animals developed chronic pancreatitis. Concomitant with the development of interstitial fibrosis, an increasing progressive atrophy of the exocrine parenchyma occurred, with preservation of the islets of Langerhans. This atrophy and fibrosis were considerable already after 2 weeks. In one piglet only there was some acute inflammation and fat necrosis, whereas all showed at least moderate chronic inflammation, which did not change with time. The growth of the piglets stopped, and all had diarrhoea, which was thought to reflect exocrine insufficiency. Two animals (9%) developed a large pancreatic pseudocyst, and all animals had wide pancreatic ducts. The endocrine function was undisturbed. Intravenous glucose tolerance tests showed that the animals did not become diabetic. This model is appropriate for the study of experimental pancreatitis.

Microangiography and dynamic computed tomography in experimental chronic pancreatitis in the pig

Chronic pancreatitis was induced in 22 piglets by dividing all pancreatic attachments to the duodenum. Ten piglets served as controls. The animals were subjected to dynamic computed tomography (CT) two, four or six weeks after operation. Microangiography was also performed on the pancreas two, four or six weeks after operation, following dynamic computed tomography. Microangiography revealed significant changes in the vasculature in advanced chronic pancreatitis. The arteries and arterioles were fewer than normal, their walls were thickened and their diameters exhibited variation. The capillary network was loose and the capillaries were not as well filled as in healthy animals. Contrast enhancement of the pancreas was, however, similar in all experimental animals to that in the healthy controls. It was concluded that the morphological changes seen in chronic pancreatitis histologically and on microangiography could not adversely affect contrast-enhanced CT because there were no changes in the function of the capillary network. On the basis of these results, dynamic CT should give no more information than CT with intravenous contrast medium in chronic pancreatitis.

Burn excision with contact neodymium: YAG laser

The newest laser modality, the contact Neodymium: YAG laser, was compared with the standard steel scalpel in excisions of full-thickness burns. Six patients with deep burns of variable sizes were included in this pilot study. The area to be operated on in each patient was divided into two areas resembling each other as much as possible in size, tissue type, and depth of injury. The results suggest that bleeding was diminished by 44% in contact laser surgery compared with the steel scalpel. Still the difference was not significant. There was no impairment of graft take after laser surgery compared with the steel scalpel. However, the laser method caused a significant increase (p less than 0.02) in operating time. The contact Nd: YAG laser can be recommended for excision of relatively small deep burn injuries, especially in areas in which bleeding is a problem with other methods.