Chronic synovitis was induced in seven sheep and nine pigs to investigate the potential applicability of laser treatment in arthroscopic synovectomy. Systemic sensitization was accomplished using chicken egg or turkey egg albumin antigens with Freund's incomplete adjuvant, enriched with killed and dried Mycobacterium tuberculosis. Ten days after the second immunizing dose, skin sensitization testing was undertaken. After a satisfactory systemic reaction had been observed, the respective antigen was injected once or twice into the left knee of each animal at 2-week intervals. After chicken egg albumin sensitization at varying systemic immunization and joint injection doses, sheep (five of five) showed neither strong morphologic nor continuous synovitis, despite a positive systemic reaction. In pigs (three of three) the inflammatory signs also were unsatisfactory for the manifestation and characterization of a synovitis model. In contrast, the application of turkey egg albumin to pigs (six of six) during the 4-month study provided a persistent, clearly manifested synovitis that developed visible villi formation and an amber to gray synovial fluid and microscopically showed follicular aggregations of lymphocytes and plasma cells. In similarly immunized sheep (two of two), only a light synovitis developed with occasional perivascular inflammatory foci.

Das Ziel dieser Arbeit war, an einem Kaninchenarthrosemodell die Gewebereaktionen infolge einer Holmiumlaser-Knorpelabtragung, konventionellmechanischer Therapie und einer Scheinoperation nach unterschiedlichen postoperativen Zeiten zu untersuchen und vergleichend zu bewerten. Bei 27 Kaninchen wurde durch Implantation einer Polyäthylenfolie in ein Kniegelenk eine Arthrose induziert. Nach 5 Monaten hatten sich deutliche arthrotische Veränderungen entwickelt. Jeweils 9 Tiere wurden einer Scheinoperation, der konventionell-mechanischen Therapie oder der Holmiumlasertherapie unterzogen. Ein Tag, ein Monat und 3 Monate postoperativ wurden jeweils 3 Tiere aus jeder Gruppe getötet und die Gelenke makroskopisch und histologisch untersucht. Drei Monate nach der konventionell-mechanischen Therapie waren die Knorpeloberflächen relativ glatt und Einrisse und Defekte weitgehend durch Faserknorpel ersetzt. Im Gegensatz dazu zeigten sich nach der Lasertherapie regelmäßig deutliche Knorpelnekrosen, z. T. Deckplatteneinbrüche und entzündliche Veränderungen bis in den Markraum hinein. Die Gelenkflächen blieben aufgerauht und weitgehend uneben. Aufgrund dieser bisherigen Ergebnisse erscheint der Einsatz des Holmiumlasers zum flächenhaften Glätten, Versiegeln oder Modellieren von Knorpelarealen der konventionell-mechanischen Therapie nicht überlegen.

The aim of this work was to investigate and evaluate the tissue reactions after sham operation and after mechanical and holmium laser chondral debridement in a rabbit model at different postoperative intervals. In 27 rabbits an arthrosis was induced by implantation of a piece of polyethylene sheeting in one knee joint. After 5 months, distinct arthritic changes had developed. Nine animals each were randomized for sham operation, mechanical debridement, and holmium laser chondral debridement. At 1 day, 1 month, and 3 months postoperatively, three animals in each group were sacrificed and their joints examined grossly and microscopically. At 3 months after mechanical debridement the articular surface was relatively smooth, and tears and defects were filled with fibrous repair tissue. After holmium laser debridement chondral necroses were regularly found, occasionally with damage to the subchondral bone and distinct inflammation in the marrow space. The articular surface remained rough and uneven. These preliminary results suggest that use of the holmium laser is not superior to mechanical methods for remodelling and smoothing of fairly large chondral areas.

The purpose of this study has been to develop a rabbit model for the assessment and follow up of angioplastic techniques which would be comparable to human arteriosclerosis. Segments of the abdominal aortas of 10 homozygous Heritable Hyperlipidemic rabbits were treated with 2 endothelial denudation procedures and collected at sacrifice after 1 week, 1 month, 2 or 3 months. Nondenuded segments of the 3 month group were taken as native controls. All sections were stained with hematoxilin/eosin and Elastica van Gieson. Pronounced intimal thickening with fibrosis, sometimes with atheromatosis developed after 1, 2, and 3 months. After 2 months calcium deposits and after 3 months frayed inner elastic membranes were found. The control segments revealed a lesser pathogenic expression with intact inner elastic membranes. In conclusion, a substantial increase in the pathogenic expression or the development of stenoses could not be obtained by 2 endothelial denudation procedures at the age of about 5 months.

The purpose of this investigation has been to demonstrate the safety of temperature controlled angioplasty (TCA) with a coaxial heating element, particularly during heat application, and to ascertain the short- and long-term arterial tissue response in 7 month old homozygous Heritable Hyperlipidemic rabbits. In 7 animals, a defined segment of the abdominal aorta was treated with TCA for 40 seconds at 175 degrees C, and 2 animals served as untreated controls. At sacrifice, 1 day, 1 and 2 weeks after TCA, in one animal each a coagulation necrosis with condensation of elastic fibers was found. One year later, 1 of 2 animals revealed irregularly structured elastic fibers combined with only minor atherosclerotic lesions. Treated segments of the second animal and of the 2 remaining animals 2 years after TCA did not appear to differ from the control segments. In conclusion, the TCA never resulted in perforation or carbonization or in adhesion of the heating element to the vascular wall, representing a safe angioplastic technique.

The goal of this study was to evaluate tissue reactions in rabbit knees following laser synovectomy using a holmium:YAG laser (wavelength: 2.1 microns) and to compare these results with those found after conventional mechanical abrasion treatment. Chronic arthritis was immunologically induced in one knee joint each of 48 rabbits. Twelve served as controls, 12 were sham-operated, 12 were exposed to laser radiation, and 12 others were treated according to conventional methods. In the laser group, a pulse length of 1 ms at a repetition rate of 3 Hz resulted in a pulse energy of 600 mJ. After periods of 1 day, 1 week and 1 and 3 months, respectively, three animals from each group were sacrificed and the synovialis was examined macroscopically and histologically using light and electron microscopy. Edema, acute inflammation, and coagulation necrosis occurred immediately following laser therapy. After 1 week, the synovial layer showed slight fibrosis, which was comparable to that found in the controls. One month later the surface appeared to be smooth. The mechanical abrasion caused hemorrhage and necrosis. Fibrosis was pronounced in all capsular layers, and after 3 months the surface appeared coarse and villous in this group. Based on these preliminary findings, holmium-laser synovectomy may offer an alternative to existing therapeutic techniques in the treatment of rheumatoid arthritis. The arthroscopic approach could prevent additional capsular fibrosis associated with mechanical irritation.

Diese Untersuchungen hatten das Ziel, die Gewebereaktion nach Laser-Synovektomie mit einem Holmium:YAG-Laser (Wellenlänge: 2,1 μm) an Kaninchen zu untersuchen und mit jener nach konventionell-mechanischer Therapie zu vergleichen. Bei 48 Kaninchen wurde immunologisch eine chronische Synoviitis in einem Kniegelenk induziert. Zwölf Tiere dienten zur Modellkontrolle. Jeweils 12 weitere Tiere wurden einer Scheinoperation, der Laserbehandlung oder der konventionell-mechanischen Abtragung unterzogen. Bei den Lasereingriffen wurden Pulsenergien vin ca. 600 mJ bei einer Pulsdauer vin 1 ms und einer Wiederholrate von 3 Hz appliziert. Nach Laufzeiten vin einem Tag, einer Woche, einem Monat und 3 Monaten wurden jeweils 3 Tiere jeder Gruppe getötet und die Synovialis makroskopisch, licht- und elektronenmikroskopisch untersucht. Unmittelbar nach der Laserbehandlung entstanden Koagulationsnekrosen, Entzündungen und Ödeme. Nach einer Woche zeigte sich im Stratum synoviale eine der Modellkontrollgruppe vergleichbare leichte Fibrose und nach einem Monat erschien die Oberfläche der Synovialis glatt. Nach der konventionell-mechanischen Abtragung traten Blutungen und Nekrosen auf. Eine vorbestehende Fibrose verstärkte sich in allen Kapselschichten. Nach 3 Monaten erschien die Oberfläche der Synovialis plumpzottig. Aufgrund dieser Ergebnisse könnte die Holmiumlaser-Synovektomie eine Alternative zu bestehenden Verfahren bei der operativen Behandlung der rheumatoiden Arthritis darstellen, gleichzeitig ware bei arthroskopischem Einsatz eine Fibrosierung der Gelenkkapsel durch die mechanische Irritation vermeidbar.

The goal of this study was to evaluate tissue reactions in rabbit knees following laser synovectomy using a holmium:YAG laser (wavelength: 2.1 mum) and to compare these results with those found after conventional mechanical abrasion treatment. Chronic arthritis was immunologically induced in one knee joint each of 48 rabbits. Twelve served as controls, 12 were sham-operated, 12 were exposed to laser radiation, and 12 others were treated according to conventional methods. In the laser group, a pulse length of 1 ms at a repetition rate of 3 Hz resulted in a pulse energy of 600 mJ. After periods of 1 day, 1 week and 1, and 3 months, respectively, three animals from each group were sacrificed and the synovialis was examined macroscopically and histologically using light and electron microscopy. Edema, acute inflammation, and coagulation necrosis occurred immediately following laser therapy. After 1 week, the synovial layer showed slight fibrosis, which was comparable to that found in the controls. One month later the surface appeared to be smooth. The mechanical abrasion caused hemorrhage and necrosis. Fibrosis was pronounced in all capsular layers, and after 3 months the surface appeared coarse and villous in this group. Based on these preliminary findings, holmium-laser synovectomy may offer an alternative to existing therapeutic techniques in the treatment of rheumatoid arthritis. The arthroscopic approach could prevent additional capsular fibrosis associated with mechanical irritation.

Atherosclerosis in rabbits was induced by administering a 2% cholesterol diet and additional endothelial denudation of the aorta and iliac artery as a model for vascular surgery. In addition, the serum cholesterol-, serum triglyceride-, and HDL-cholesterol values were examined. After 22 weeks the intima and most often the media showed atheromatosis and fibrosis, in most of the arteries with intimal necroses. All arteries developed marked to pronounced stenoses, calcium deposits were only observed in single cases. The intensity of the arterial lesions was found to be similar to the appearance of human atherosclerosis.

The goal of this investigation was to improve the reliability of intraoperative and postoperative hemostasis and to observe the healing process after using a combined technique of tissue freezing followed by the application of collagen fleece and fibrin glue for the treatment of splenic ruptures. Grade II lesions were inflicted on the spleens of 15 swine. The bleeding wounds were frozen for 1 min at -60-degrees-C using a cryosurgical device. Immediately afterwards the frozen lesions were covered with fibrin glue and collagen fleece and kept under slight compression. In every case complete hemostasis was achieved intraoperatively. The spleens of three animals each time were collected for gross and microscopic examination after 2 days and 1, 2, 5, and 6 weeks. A visceroperitoneal adhesion was observed in only one spleen, U-shaped viscerovisceral adhesions in five spleens. Superficial coagulation necroses could be detected microscopically only after 2 days and 1 week. Organization of the wounds, indicated by granulation tissue which contained siderophages, started in the 2nd week. There was distinct formation of collagen fibers after 5 and 6 weeks, only a residue of the collagen fleece was visible and the surplus fibrin glue was encapsulated. With this combined technique complete and safe hemostasis and a good subsequent healing process was achieved.

Das Ziel dieser Untersuchungen war, die Zuverlässigkeit der Hämostase in der intra- und postoperativen Phase und den Heilungsverlauf bei der Anwendung einer kombinierten Technik von Kryochirurgie und kollagenvliesgestützter Fibrinklebung bei der Therapie von Milzrupturen zu verbessern. An 15 Schweinen wurden Läsionen an der Milz gesetzt, die der Verletzungsart des Grad II entsprachen. Die blutende Wundfläche wurde für 1 min bei −60 °C vereist und die gefrorene Läsion mit Fibrinkleber und Kollagenvlies abgedeckt; danach wurde für 1 min eine digitale Kompression der Wundfläche ausgeübt. In jedem Falle wurde intraoperativ eine vollständige Hämostase erreicht. Nach den operativen Eingriffen wurden bei jeweils 3 Tieren nach Laufzeiten von 2 Tagen, 1, 2, 5 und 6 Wochen die therapierten Milzen entnommen und histologisch untersucht. Eine Verwachsung mit dem Peritoneum trat nur bei 1 Tier auf und bei 5 Tieren waren die Milzen u-förmig verklebt. Histologisch war eine oberflächliche Koagulationsnekrose nur nach 2 Tagen und 1 Woche nachweisbar. Der Nachweis von siderophagenhaltigem Granulationsgewebe als Zeichen der Organisation begann mit der 2. Woche, die Bildung von Narbenkollagen war ab der 5. Woche deutlich ausgeprägt. Nach 5 und 6 Wochen waren nur noch Reste des Kollagenvlieses sichtbar und der überschüssige Fibrinkleber war abgekapselt. Im Tierexperiment ließ sich mit diesem kombinierten Verfahren eine sichere und vollständige Hämostase mit einem nachfolgend guten Heilungsverlauf erreichen.

The goal of this investigation has been to improve the safety of intra- and post-operative haemostasis in splenic lesions by a combined technique of tissue freezing followed by the application of collagen fleece and fibrin glue in an animal study. The progression of healing was observed after different periods of time. Grade II lesions were set on the spleens of 15 pigs. The wounds were frozen for 1 m at -60 degrees C with a cryosurgical probe and afterwards sealed with fibrin glue and collagen fleece. In every case, complete haemostasis was achieved intraoperatively. The spleens of 3 animals each were examined microscopically after 2 days, 1, 2, 5 and 6 weeks, respectively. A visceroperitoneal adhesion was observed in only 1 spleen and u-shaped viscerovisceral adhesions in 5 spleens. Superficial coagulation necroses were observed only in specimens removed after 2 days and 1 week, respectively. Complete and safe haemostasis followed by acceptable subsequent healing was achieved using this combined technique.

The goal of this investigation was to improve the reliability of intraoperative and postoperative hemostasis and to observe the healing process after using a combined technique of tissue freezing followed by the application of collagen fleece and fibrin glue for the treatment of splenic ruptures. Grade II lesions were inflicted on the spleens of 15 swine. The bleeding wounds were frozen for 1 min at -60 degrees C using a cryosurgical device. Immediately afterwards the frozen lesions were covered with fibrin glue and collagen fleece and kept under slight compression. In every case complete hemostasis was achieved intraoperatively. The spleens of three animals each time were collected for gross and microscopic examination after 2 days and 1, 2, 5, and 6 weeks. A visceroperitoneal adhesion was observed in only one spleen, U-shaped viscerovisceral adhesions in five spleens. Superficial coagulation necroses could be detected microscopically only after 2 days and 1 week. Organization of the wounds, indicated by granulation tissue which contained siderophages, started in the 2nd week. There was distinct formation of collagen fibers after 5 and 6 weeks; only a residue of the collagen fleece was visible and the surplus fibrin glue was encapsulated. With this combined technique complete and safe hemostasis and a good subsequent healing process was achieved.

Holmium‐laser synovectomy was carried out to remove allergically inflamed synovial membranes in rabbit knee joints. The healing process was then investigated at different periods. Left knee joints of 12 rabbits were exposed to Ho:YAG‐laser radiation at a wavelength of 2.1 μm, pulse energy of 600 mJ, pulse length of 1 ms, and repetition rate of 3 Hz. Twelve others were treated conventionally and 12 served as controls. After 1 day, 1 week, and 1 and 3 months, respectively, 3 animals from each group were sacrificed and the synovialis grossly and microscopically examined. Coagulation necrosis, inflammation, and edema resulted following laser therapy. After 1 week, the synovial layer consisted of a scarlike formation of fibers and within 1 month, its surface appeared smooth. The mechanical abrasion caused hemorrhage and necrosis. Fibrosis developed in the capsular layers, and after 3 months, the surface appeared coarse and villous. Based on these preliminary findings, holmium‐laser synovectomy may offer an alternative method to existing therapeutic techniques. © 1992 Wiley‐Liss, Inc.

The purpose of this investigation was to follow the course of the serum cholesterol, serum triglyceride and HDL cholesterol concentrations of heritable hyperlipidemic (HHL) rabbits (34 animals in total) in order to obtain an early prediction of these parameters, which appear to be highly associated with the presence of arteriosclerotic lesions. Measurements were done at 6-week intervals for one year, beginning at the 10th week of age. At week 10 the serum cholesterol concentration of females was 652.80 mg x dl-1 +/- 103.82 (standard deviation) and that of males was 648.84 mg x dl-1 +/- 146.04. The 10-week serum triglyceride concentration of males was 267.90 mg x dl-1 +/- 93.03, which decreased in two marked steps after week 10 and 40, while that of females was 246.70 mg x dl-1 +/- 67.51, which reached a maximum at 7 months and then decreased. Both the serum cholesterol and the serum triglyceride concentrations decreased significantly in males and females during the investigation period. The 10-week HDL cholesterol concentrations (males: 18.08 mg x dl-1 +/- 12.81; females: 14.61 mg x dl-1 +/- 8.56) remained relatively constant in both sexes during the investigation period. We consider one or two samplings, usually at weaning and at the beginning of an investigation, to ensure reliable biochemical parameters for the state of the animals.