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ABSTRACT: In 11 female and 13 male patients 29 symptomatic femoropopliteal occlusions were treated with a novel intraluminal endarterectomy device (REDHA-CUT). The pre-existing stenoses (71 +/- 9%) could be reduced to 29 +/- 18% (means +/- s.d.). The arteriectomy procedure with this device took on average 5 +/- 3 min. Neither perforations nor dissections nor distal embolisms or any other complications were observed. In comparison with other percutaneous transluminal angioplasty procedures the clinical use of the novel REDHA-CUT device is safe, simple and fast and allows for the retrieval of plaque biopsies.
Swiss Surgery 02/1996;
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ABSTRACT: The purpose of this study was to characterize postangioplasty myointimal hyperplasia as compared to primary atheroma of superficial femoral arteries using color-coded duplex sonography (CCD), and to correlate sonographic findings with the histopathology of samples obtained from these lesions by catheter atherectomy (Redha-cut device). Preinterventionally, homogeneity, echogeneity, and the surface of plaques were described using CCD in nine cases with secondary stenoses after percutaneous transluminal angioplasty and in seven cases with primary atheroma. Myointimal hyperplasia of femoral restenoses showed a homogeneous (7 of 9 vs. 1 of 7) and hypoechogenic (7 of 9 vs. 0 of 7) wall thickening compared to primary atheromas (p < 0.05). Primary atherosclerotic plaques showed a rather heterogeneous, hypo- and hyperechogenic ultrasonic appearance with or without echo shadowing in six of seven cases. The surface of restenoses was more often regular than that of primary atherosclerotic lesions, but this finding did not reach statistical significance (6 of 9 vs. 2 of 7, p = 0.14). Thrombotic material appeared homogeneous and hypoechogenic in three of five cases and could not be discriminated from intimal hyperplasia. In summary, postangioplasty intimal hyperplasia is characterised by a hypoechogenic, homogeneous, rather regularly confined vessel wall thickening and can be differentiated from primary atheroma at CCD.
Ultrasound in Medicine & Biology 01/1996; 22(7):815-21. · 2.29 Impact Factor
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ABSTRACT: Ischemia as a causative factor for acute pancreatitis has been discussed for decades but has only recently gained wider acceptance. Chronic pancreatitis, however, has rarely been attributed to ischemic injury. While experimental evidence is available for the ischemic pathogenesis of acute pancreatitis, no studies have been reported about pancreatic ischemia as a single cause of chronic pancreatitis. Also, the progression from acute to chronic pancreatitis has been a very controversial issue. To address both questions we have injected polystyrene microspheres of 20-microns diameter into the pancreatic branches of the splenic artery of 36 rats. Thirteen more rats were sham operated and injected with saline. The animals were killed at 1, 2, 3, and 9 weeks after operation and macroscopically and histologically examined, and serum alpha-amylase and weight gain were determined. For the pancreas the following parameters were assessed using a score from 0 (no change) to 4 (severe change): atrophy, hemorrhage, edema, fat necrosis, acinar necrosis, polymorphonuclear infiltration, mononuclear infiltration, interstitial fibrosis, and ductal changes. While no difference between control and experiment was observed for serum alpha-amylase, weight gain, edema, and hemorrhage, persistent differences were evident for the parameters characteristic of chronic pancreatitis, most significantly for interstitial fibrosis, ductal changes, mononuclear infiltration, acinar necrosis, and atrophy. No spontaneous deaths occurred. The severity of the lesions remained stationary after the first week. Our work shows for the first time that pancreatic ischemia by microvascular hypoperfusion can cause histopathologic changes characteristic of chronic pancreatitis and that these changes follow acute necrotizing pancreatitis.
Pancreas 12/1995; 11(4):374-81. · 2.39 Impact Factor
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ABSTRACT: Extracorporeal shock-wave lithotripsy (ESWL) has rapidly become established worldwide as a routine method for treatment of nephro- and ureterolithiasis. Although initial studies showed no tissue-damaging effect by the shock waves, we found, in an animal experiment using canine kidneys, that the ESWL-induced damage to the renal parenchyma is more marked than originally assumed. The damage is limited to the area that was focused on, and heals relatively rapidly by connective tissue encapsulation with final cicatrisation without any further residual effects being observed up to the present. This parenchymal damage is probably also the cause of the macrohematuria that is always observed during therapy. The resulting tissue damage is not extensive enough to cause a demonstrable reduction of function as measured by the usual methods (serum creatinine, creatinine clearance, isotopy renography, i.v. urography). In serum we observed a transient decrease of calcium, an immediate increase of lactate-dehydrogenase, transaminases (SGOT and SGPT) and a delayed increase of alkaline phosphates. Creatinine, blood urea nitrogen, sodium, potassium and amylase remained within normal limits. In urine, a decrease of creatinine and an increase of glucose excretion were noted. We believe that these changes represent a relatively mild and transient damage of renal cells and do not reflect the occasionally heavy morphological changes observed after shock-wave exposure. The main clinical complication is the large subcapsular hematoma which, according to the present knowledge, could well result from a lesion of the larger peripheral vessels. Damage to other organs such as subserous colonic and small bowel hematomata are to be expected although they do not lead to clinical symptoms.
Urologia Internationalis 02/1995; 54(1):48-58. · 0.99 Impact Factor
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ABSTRACT: Vascular surgery in growing organisms is still problematic. Especially in surgical therapy of coarctation of the aorta, high restenose rates are documented if non-absorbable polypropylene and running suture technique ist used. Theoretically, absorbable suture material allows a running suture technique with less restenose rates. Our study compares absorbable (polyglyconat and polydioxanon) with non-absorbable (polypropylene) suture material for repair of aorta in growing dogs. Anastomoses performed with absorbable suture material show after one year very good functional results without any local complications. In conclusion we can say that absorbable suture material allows formation of safety vascular anastomoses and doesn't impair growth of anastomoses.
Helvetica chirurgica acta 01/1995; 60(6):901-5.
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ABSTRACT: The adequacy of retrograde delivery of cardioplegic solution to the right ventricle ist controversial. To evaluate this issue, we excised the plegic heart in 11 bovine experiments and infused an India ink solution (10 ml of India ink in 300 ml NaCl 0.9%) into the coronary sinus (n = 7) at a pressure of 60 cm H2O and into the aortic root (n = 4) at a pressure of 120 cm H2O. After fixation, the ventricles were cut in 11 transversal slices. The portion of coloured (= perfused) ventricular myocardium was calculated with computer-aided morphometric analysis. With antegrade infusion, 95 +/- 5% (mean +/- standard deviation) of the left ventricular volume (left ventricular free wall plus interventricular septum) was stained, with retrograde infusion 94 +/- 3%. Perfusion of the right ventricle was significantly lower with retrograde infusion (antegrade infusion 93 +/- 8%, retrograde 45 +/- 13%, p < 0.001), especially in the basal segments (basal vs. apical: 16 +/- 26% vs. 82 +/- 5%, p < 0.001). The adequate delivery of retrograde infusion to the left ventricle and septum allows good left ventricular myocardial protection with retrograde cardioplegia. Because the retrograde delivery to the right ventricle is markedly inadequate and nonuniform, the quality of right ventricular protection with retrograde cardioplegia has to be questioned.
Helvetica chirurgica acta 12/1993; 60(3):435-8.
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ABSTRACT: In 40 human cadaver arteries endarterectomy was performed using a new intravascular device. The system and technique are described. According to our preliminary laboratory experiences the new device proofed to be save and effective. It will allow us to approach more complex lesions not ideal for balloon angioplasty. Clinical investigations will be performed in the near future.
Helvetica chirurgica acta 09/1992; 59(2):311-4.
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ABSTRACT: Several case reports exist which demonstrate cholesterol crystals to be the cause of acute pancreatitis in humans. The crystals have been found intravascularly in the pancreas and at least in one case the origin of the crystals was known. We have undertaken to experimentally reproduce this pathogenetic mechanism in the rat. 30 rats were subjected to the following procedures: under anaesthesia the splenic artery was distally ligated and proximally cannulated; 16 control animals were injected via the cannula with saline (8 rats), particle free cholesterol saturated physiologic saline (3 rats) or nothing (5 rats). 14 rats were injected with ca. 400 microliters of a dilute suspension of cholesterol crystals of 5-40 microns diameter in cholesterol saturated physiologic saline. The abdomen was closed and after 24 h all animals were killed. Acute pancreatitis was diagnosed in all animals that received cholesterol microcrystals and in none of the controls. The diagnosis was based on macroscopic and histological findings. Acute pancreatitis was of focal, disseminated, necrotic type with oedema and moderate haemorrhage and fat necrosis. Only those parts of the pancreas were affected which were supplied by branches of the distal splenic artery used for retrograde injections of cholesterol crystals. This model supports the notion that microembolic or microthrombotic events play a pivotal role in the pathogenesis of spontaneous acute pancreatitis.
Helvetica chirurgica acta 04/1992; 58(5):611-5.
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ABSTRACT: Alterations in the vascular bed of the pancreas or disturbances of the blood coagulation system are mostly considered to be sequelae of acute pancreatitis, but it seems that impairment of the pancreatic blood supply can per se lead to acute hemorrhagic pancreatitis. To test this hypothesis with a new animal model, we injected 20 microns polystyrene microspheres retrogradely into the distal splenic artery of rats, thus incompletely blocking blood perfusion in the splenic portion of the pancreas. Eight of eight rats (100%) subjected to microsphere injection developed acute hemorrhagic pancreatitis by 27 h after surgery, when they were killed, but none of the six sham-operated control animals (0%) showed macroscopic signs of pancreatitis. Blood amylase levels at death were 3,087 +/- 650 I.U./L (mean +/- SEM) and the histologic severity score for pancreatitis was 10.8 +/- 1.0 (mean +/- SEM), whereas in the six control rats amylase levels were 1,375 +/- 158 I.U./L and the histology score was only 1.7 +/- 1.0. The result is, with p less than 0.0005, highly significant (chi 2 analysis) and shows that acute experimental pancreatitis can indeed be induced by partially blocking the arterial blood supply within the organ.
Pancreas 04/1990; 5(2):188-93. · 2.39 Impact Factor
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ABSTRACT: Open-chest left heart bypass was performed in 10 canine experiments (30 +/- 9 kg) by a servo controlled roller pump for 6 h at a pump flow of 50 ml/min per kg bodyweight. The surfaces of the tubing sets were either standard (with systemic heparinization) or with end-point attached heparin (no systemic heparin). Besides continuous monitoring of hemodynamics, a standard battery of blood samples was taken before bypass, after 10 min and every hour thereafter. There is no evidence of increased fibrin production in the group with end-point attached heparin surfaces perfused without systemic heparinization. Superior hemodynamics in left heart bypass performed without systemic heparinization appear to be due to improved hemostasis, reduced blood loss and therefore reduced transfusion requirements. Left heart bypass with heparin-coated equipment has been successfully used for resection of a thoracoabdominal aneurysm in six patients.
European Journal of Cardio-Thoracic Surgery 02/1990; 4(7):384-8; discussion 389. · 2.55 Impact Factor
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ABSTRACT: The effect of cyclosporine A (CsA), an immunosuppressive agent used in transplantation, on wound healing following microsurgical neoimplantation of a ureter in the bladder of 63 SIV ZUR rats was examined morphologically using the light and scanning electron microscopes and functionally by radiography. Following ureterocystoneostomy (UCN) on the right side, the animals in Group I (control group) received 1.0 ml CsA solvent (0.1 g ethanol and 0.3 g intralipid) per day. Group II received 12.5 mg/kg/day CsA and Group III 17.5 mg/kg/day CsA. All drugs were administered i.p. A third of the animals in each group were reoperated 7, 14 or 28 days after UCN. At these time intervals, there were no radiologically demonstrable differences in the operated side. Examination under the scanning electron microscope indicated delayed restitution of epithelium in the bladder for rats which had received CsA as compared to the control group. In the area of the UCN, CsA caused dose-independent retardation of the regenerative hyperplasia associated with wound healing (Group I: max. 7 days after UCN: Group II and Group III, max. 14 days after UCN). Hyperplastic areas had ropy microridges and uniform short microvilli. Where the hyperplasia exhibited nodular and papillary formation, also histologically more evident under CsA, occasional epithelial cells had pleomorphic microvilli on their luminal surface. Unlike other known premalignant changes of this kind, the frequent occurrence of pleomorphic microvilli under CsA was reversible. In general, CsA led to dose-unrelated protraction of UCN wound healing with no lasting functional disturbance in rats.
Urological Research 02/1989; 17(1):21-6. · 1.23 Impact Factor
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Helvetica chirurgica acta 12/1988; 55(4):483-8.
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ABSTRACT: A disposable ventricle assist device (VAD) including atrium, ventricle and trileaflet valves (all polyurethane) can be driven either a) by its original self adjusting drive unit (ABIOMED BVS 5000) or b) by a standard intra-aortic balloon pump console (DATASCOPE). Maximum flow in vitro was 4.3 l/min with the original drive console versus 9.2 l/min for activation with the intra-aortic balloon pump console. Performance characteristics of the VAD were evaluated in 11 bovine experiments. In vivo left ventricular assist for up to 24 hours with VAD and either original drive console or standard intra-aortic balloon pump console showed superior flow on activation with the intra-aortic balloon pump console (5.3 +/- 1.7 l/min) versus original drive console (3.5 +/- 0.5 l/min). After 6 hours of assist (before any transfusions) there was no significant difference in classic parameters for evaluation of blood trauma such as plasma hemoglobin production, LDH production and platelet depletion. We conclude that VAD is extremely simple to use. Activation by an intra-aortic balloon pump console enables significant increase of VAD-output without detectable increase of blood trauma. Successful weaning of VAD activated with standard intra-aortic balloon pump console was possible in a first clinical application.
The Thoracic and Cardiovascular Surgeon 07/1988; 36(3):146-50. · 0.88 Impact Factor
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ABSTRACT: Extracorporal shock wave lithotripsy has rapidly become established world wide as a routine method for treatment of nephro-and ureterolithiasis. Although initial studies showed no tissue damaging effect by the shock waves, we found in an animal experiment using canine kidneys, the ESWL induced damage to the renal parenchyma is more marked than originally assumed. The damage is limited to the area that was focused on, and heals relatively rapidly by connective tissue encapsulation with final cicatrisation without any further residual effects being observed until now. This parenchymal damage is probably also the cause of the macrohaematuria that is always observed during therapy. The resulting tissue damage is not extensive enough to cause demonstrable reduction of function as measured by the usual methods (serum creatinine, creatinine clearance, isotopy renography, i/v-urography). The main clinical complication is the large subcapsular haematoma which, according to present knowledge, could well result from a lesion of the larger peripheral vessels. Damage to other organs such as subserous colonic and small bowel haematomata are to be expected although they do not lead to clinical symptoms.
Urological Research 05/1988; 16(3):161-166. · 1.23 Impact Factor
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ABSTRACT: Extracorporal shock wave lithotripsy has rapidly become established world wide as a routine method for treatment of nephro- and ureterolithiasis. Although initial studies showed no tissue damaging effect by the shock waves, we found in an animal experiment using canine kidneys, the ESWL induced damage to the renal parenchyma is more marked than originally assumed. The damage is limited to the area that was focused on, and heals relatively rapidly by connective tissue encapsulation with final cicatrisation without any further residual effects being observed until now. This parenchymal damage is probably also the cause of the macrohaematuria that is always observed during therapy. The resulting tissue damage is not extensive enough to cause demonstrable reduction of function as measured by the usual methods (serum creatinine, creatinine clearance, isotopy renography, i/v-urography). The main clinical complication is the large subcapsular haematoma which, according to present knowledge, could well result from a lesion of the larger peripheral vessels. Damage to other organs such as subserous colonic and small bowel haematomata are to be expected although they do not lead to clinical symptoms.
Urological Research 02/1988; 16(3):161-6. · 1.23 Impact Factor
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ABSTRACT: The influence of vascular disorders on the etiology of acute pancreatitis is increasingly recognized. However, the pathophysiologic mechanism is unclear. We report a 65-year-old patient with known cardiovascular disease and aneurysm of the abdominal aorta who sustained three bouts of acute pancreatitis. Each time he improved upon conservative treatment. After aortocoronary bypass operation and y-graft replacement of the abdominal aorta he experienced a forth bout of pancreatitis from which he did not recover. The patient died on the 17th postoperative day. Histological examination of the pancreas showed fresh and old cholesterol emboli in small arteries and extensive acute necrotizing pancreatitis combined with focal fibrosis. From these findings we conclude that recurrent acute pancreatitis was caused by recurrent atheromatous embolization.
Digestive Surgery. 08/1970; 9(2):116-119.
