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Surgical Trauma (surgical + trauma)
Selected AbstractsEffects of intravenous anesthetics on interleukin (IL)-6 and IL-10 production by lipopolysaccharide-stimulated mononuclear cells from healthy volunteersACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2002M. Takaono Background: Surgical trauma has been shown to augment the plasma concentrations of proinflammatory cytokines, which are important mediators of host defense mechanisms and the systemic inflammatory response syndrome (SIRS). Recently, it has been shown that certain kinds of surgery provoke not only a proinflammatory response (SIRS) but also a concurrent anti-inflammatory response. The aim of this study was therefore to examine the effects of intravenous anesthetics on the synthesis of interleukin (IL)-6 (a proinflammatory cytokine) and IL-10 (an anti-inflammatory cytokine) by lipopolysaccharide (LPS)-stimulated mononuclear cells from healthy volunteers. Methods: Peripheral blood mononuclear cells (PBMCs) from 17 healthy volunteers, separated by centrifugation on a Ficoll-Hypaque gradient, were washed and suspended in RPMI containing 10% heat-inactivated fetal calf serum (FCS). After adding RPMI-FCS containing various concentrations of intravenous anesthetics (propofol, thiopental, ketamine and midazolam), the PBMCs were incubated overnight in the presence of a submaximal concentration of LPS. The supernatants were collected and their IL-6 and IL-10 contents were assayed using enzyme-linked immunosorbent assay kits. Results: Propofol inhibited both IL-6 and IL-10 production at 0.5 µg/mL, 5 µg/mL and 50 µg/mL. Conversely, thiopental induced IL-10 production at 2 µg/mL and 20 µg/mL. Conclusion: Propofol appears to inhibit both IL-6 and IL-10 production by LPS-stimulated PBMCs in vitro. Further study is required to clarify the mechanism of the suppressive effect of propofol. [source] Quality of life in patients with right- or left-sided brain tumours: literature reviewJOURNAL OF CLINICAL NURSING, Issue 11 2008Alvisa Palese Bcsn Aims., To determine if patients with left- or right-sided hemisphere neoplasm perceive their quality of life (QoL) differently. Background., It is not clear whether patients with a lesion in the left hemisphere have a different QoL than those with a lesion in the right hemisphere. (1) In the pre-operative period, patients with a left-sided lesion may have different symptoms according to the position of the tumour. (2) Studies on patients with brain injury demonstrate an association between left frontal lesions and depression: depression can alter the patients' perception of QoL. (3) In the postoperative period, right-handed patients may be disadvantaged by surgical trauma to the motor cortex in the left hemisphere. (4) During the different phases of the disease, the various functions of the two hemispheres may influence the patient's capacity to control QoL; also, as suggested by authors, both the ego and the conscience are mostly located in the left hemisphere. This is the reason that patients with a left-sided lesion may perceive a worse QoL. Methods., A review of literature was carried out using the Medline database (1966,2007) and CINHAL (1982,2007), using the following Mesh Terms and key words: brain neoplasm, tumour or cancer, hemispheric dominance or laterality or right or left hemisphere, QoL. Results., Seven studies emerged that documented non-homogeneous results and which included different populations. The association between QoL and the side of the lesion was evaluated. Conclusions., The lack of a substantial number of recent, robust follow-up studies investigating the QoL in patients at different stages of disease and treatment indicates that more research is needed. Relevance to clinical practice., Understanding the QoL in patients with brain neoplasm and the differences between right and left hemisphere sites of the neoplasm can help nurses develop different interventions and offer more guidance for effective clinical intervention. [source] Tissue alterations after tooth extraction with and without surgical trauma: a volumetric study in the beagle dogJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 4 2008Stefan Fickl Abstract Objectives: The aim of this study is to evaluate whether tooth extraction without the elevation of a muco-periosteal flap has advantageous effects on the resorption rate after tooth extraction. Material and Methods: In five beagle dogs polyether impressions were taken before the surgery. The roots of the first and second pre-molars (P1 and P2) were extracted and the sites were assigned to one of the following treatments: treatment group (Tx) 1, no treatment; Tx 2, surgical trauma (flap elevation and repositioning); Tx 3, the extraction socket was filled with BioOss Collagen® and closed with a free soft-tissue graft; Tx 4, after flap elevation and repositioning, the extraction socket was treated with BioOss Collagen® and a free soft-tissue graft. Impressions were taken 2 and 4 months after surgery. The casts were scanned, matched together with baseline casts and evaluated with digital image analysis. Results: The "flapless groups" demonstrated significant lower resorption rates both when using socket-preservation techniques and without. Furthermore, socket-preservation techniques yielded better results compared with not treating the socket. Conclusion: The results demonstrate that leaving the periosteum in place decreases the resorption rate of the extraction socket. Furthermore, the treatment of the extraction socket with BioOss Collagen® and a free gingival graft seems beneficial in limiting the resorption process after tooth extraction. [source] Less systemic cytokine response in patients following microendoscopic versus open lumbar discectomyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2005Tsung-Jen Huang Abstract The magnitude of the tissue damage from surgery impacts the trauma response. This response is proportional to the severity of surgical stress. Systemic cytokines are recognized as markers of postoperative tissue trauma. Microendoscopic discectomy (MED) recently has become popular for treating lumbar disc herniations, and is associated with favorable clinical outcomes compared with open discectomy (OD). This study postulates that MED is a less traumatic procedure, and therefore has a lower surgical stress response compared to OD. In this study, a quantitative comparison of the overall effects of surgical trauma resulting from MED and OD was performed through analyzing patient systemic cytokines response. From April, 2002 to June, 2003, 22 consecutive patients who had symptomatic lumbar disc herniations were prospectively randomized to undergo either intracanalicular MED (N = 10) or OD (N = 12). In this study, the Vertebroscope System (Zeppelin, Pullach, Germany) was used to perform the endoscopic discectomy procedure in all MED patients. Serum levels of tumor necrosis factor-, (TNF-,), Interleukin-1, (IL-1,), Interleukin-6 (IL-6), and Interleukin-8 (IL-8) were measured before surgery and at 1, 2, 4, 8 and 24h after surgery using an enzyme-linked immunosorbent assay. Serum C-reactive protein (CRP) was measured at the same time interval. The results showed the MED patients had shorter postoperative hospital stay (mean, 3.57 ± 0.98 vs. 5.92 ± 2.39 days, p = 0.025) and less intraoperative blood loss (mean. 87.5 ± 69.4 vs. 190 ± 115 ml, p = 0.042). The operating length, including the set-up time, was longer in the MED group (mean, 109 ± 35.9 vs. 72.1 ± 17.8 min, p = 0.01). The mean size of skin incision made for the MED patients was 1.86 ± 0.13cm (range 1.7,2.0cm); and 6.3 ± 0.98 cm for the OD patients (range 5.5,8cm), p = 0.001. The patients' pain severity of the involved limbs on 10-point Visual Analog Scale before operation in MED group was 7.5 ± 0.3 (range 6,9) and 8 ± 0.2 (range 7,9) in OD group, p = 0.17; and after surgery, 1.5 ± 0.2 (range 1,2) in MED group and 1.4 ± 0.1 (range 1,3) in OD group, p = 0.91. CRP levels peaked at 24h in both groups, and OD patients displayed a significantly greater postoperative rise in serum CRP (mean, 27.78 ± 15.02 vs. 13.84 ± 6.25mg/l, p = 0.026). Concentrations of TNF-,, IL-1,, and IL-8 were detected only sporadically. Serum IL-6 increased less significantly following MED than after OD. In the MED group, IL-6 level peaked 8 h after surgery, with the response statistically less than in the open group (mean, 6.27 ± 5.96 vs. 17.18 ± 11.60pg/ml, p = 0.025). A statistically significant correlation was identified between IL-6 and CRP values (r = 0.79). Using the modified MacNab criteria, the clinical outcomes were 90% satisfactory (9/10) in MED patients and 91.6% satisfactory (11/12) in OD patients at a mean 18.9 months (range 10,25) follow-up. Based on the current data, surgical trauma, as reflected by systemic IL-6 and CRP response, was significantly less following MED than following OD. The difference in the systemic cytokine response may support that the MED procedure is less traumatic. Moreover, our MED patients had achieved satisfactory clinical outcomes as the OD patients at a mean 18.9 months follow-up after surgery. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Cover Picture , Mol.MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2009Nutr. Regular issues provide a wide range of research and review articles covering all aspects of Molecular Nutrition & Food Research. Selected topics of issue 6 are: Quercetin-induced apoptotic cascade in cancer cells: Antioxidant versus estrogen receptor ,-dependent mechanisms. Bog blueberry anthocyanins alleviate photoaging in ultraviolet-B irradiation-induced human dermal fibroblasts Oxidative stress due to anesthesia and surgical trauma: Importance of early enteral nutrition [source] Oxidative stress due to anesthesia and surgical trauma: Importance of early enteral nutritionMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2009Katerina Kotzampassi Abstract Anesthesia and surgical trauma are considered major oxidative and nitrosative stress effectors resulting in the development of SIRS. In this study we evaluated the usefulness of early enteral nutrition after surgical trauma. Sixty male Wistar rats were subjected to midline laparotomy and feeding-gastrostomy. Twenty of these rats served as controls after recovering from the operation stress. The remaining rats received, through gastrostomy, enteral nutrition or placebo-feeding for 24 h. Oxidative stress markers and CC chemokine production were evaluated in rat serum and liver tissue. The operation itself was found to increase nitric oxide (NO) and malondialdehyde (MDA) and to decrease superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as liver tissue energy charge (EC) in relation to controls. The rats receiving enteral feeding exhibited statistically significantly lower levels of NO and MDA, and higher levels of SOD, GSH-Px, and liver EC, in relation to placebo feeding rats. The operation significantly increased the chemokines monocyte chemoattractant protein (MCP)-1 and regulated upon activation, normal T-cell expressed, and secreted (RANTES) in rat serum, while enteral nutrition caused a further significant increase in chemokine levels in serum. mRNA chemokine expression in liver was increased in a similar pattern. These findings indicate that early enteral feeding might play an important role after surgery ameliorating oxidative stress, affecting positively the hepatic EC and regulating, via chemokine production, cell trafficking, and healing process. [source] Genome-Wide Transcription Profile of Endothelial Cells After Cardiac Transplantation in the RatAMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010B. Mikalsen Transcriptome analyses of organ transplants have until now usually focused on whole tissue samples containing activation profiles from different cell populations. Here, we enriched endothelial cells from rat cardiac allografts and isografts, establishing their activation profile at baseline and on days 2, 3 and 4 after transplantation. Modulated transcripts were assigned to three categories based on their regulation profile in allografts and isografts. Categories A and B contained the majority of transcripts and showed similar regulation in both graft types, appearing to represent responses to surgical trauma. By contrast, category C contained transcripts that were partly allograft-specific and to a large extent associated with interferon-,-responsiveness. Several transcripts were verified by immunohistochemical analysis of graft lesions, among them the matricellular protein periostin, which was one of the most highly upregulated transcripts but has not been associated with transplantation previously. In conclusion, the majority of the differentially expressed genes in graft endothelial cells are affected by the transplantation procedure whereas relatively few are associated with allograft rejection. [source] Role of interleukin-1, in postoperative cognitive dysfunctionANNALS OF NEUROLOGY, Issue 3 2010Mario Cibelli MD Objective: Although postoperative cognitive dysfunction (POCD) often complicates recovery from major surgery, the pathogenic mechanisms remain unknown. We explored whether systemic inflammation, in response to surgical trauma, triggers hippocampal inflammation and subsequent memory impairment, in a mouse model of orthopedic surgery. Methods: C57BL/6J, knock out (lacking interleukin [IL]-1 receptor, IL-1R,/,) and wild type mice underwent surgery of the tibia under general anesthesia. Separate cohorts of animals were tested for memory function with fear conditioning tests, or euthanized at different times to assess levels of systemic and hippocampal cytokines and microglial activation; the effects of interventions, designed to interrupt inflammation (specifically and nonspecifically), were also assessed. Results: Surgery caused hippocampal-dependent memory impairment that was associated with increased plasma cytokines, as well as reactive microgliosis and IL-1, transcription and expression in the hippocampus. Nonspecific attenuation of innate immunity with minocycline prevented surgery-induced changes. Functional inhibition of IL-1,, both in mice pretreated with IL-1 receptor antagonist and in IL-1R,/, mice, mitigated the neuroinflammatory effects of surgery and memory dysfunction. Interpretation: A peripheral surgery-induced innate immune response triggers an IL-1,-mediated inflammatory process in the hippocampus that underlies memory impairment. This may represent a viable target to interrupt the pathogenesis of postoperative cognitive dysfunction. ANN NEUROL 2010;68:360,368 [source] Viral reactivation is not related to septic complications after major surgical resections,APMIS, Issue 4 2008T. VOGEL Anastomotic leakage and septic complications are the most important determinants of postoperative outcome after major surgical resections. Malignant diseases and surgical trauma can influence immune responses and the ability to react against infectious factors, such as bacteria and viruses. Comparable immune suppression can cause viral reactivation in transplantation and trauma patients. In this prospective study, patients who underwent major surgical resections for oesophageal or pancreatic cancer were investigated for the potential involvement of viral reactivation in the development of septic complications. 86 patients (40 oesophageal resections, 27 pancreatic resections, 19 surgical explorations) were included. Viral antigens, viral DNA, antibodies against viral structures (IgG, IgM, IgA) and, in part, viral cultivation were performed for CMV, EBV, HSV1, HSV2, HZV6 and VZV in serum, urine, sputum and swabs from buccal mucosa preoperatively and at postoperative days 1, 3 and 5. Test results were compared with the postoperative outcome (30-day morbidity, in-hospital mortality) and clinical scores (SOFA, TISS). For statistical analyses Student's t -tests and Chi2 -tests were used. The overall complication rate was 19.8% (30-day morbidity) with an in-hospital mortality of 1.2% (1/86 patients). Postoperatively, anti-CMV-IgG titres were significantly reduced (p<0.05) and remained suppressed in patients with septic complications. Anti-CMV-gB-IgG were also reduced, but showed considerable interindividual differences. Anti-CMV-IgA and -IgM did not show significant alterations in the postoperative course. In addition, direct viral detection methods did not support viral reactivation in patients in any of the investigated groups. The reduction of anti-CMV antibodies is likely caused by an immune suppression, specifically by reduced B-cell counts after major surgical interventions. Viral reactivation, however, did not occur in the early postoperative period as a specific risk for septic complications. [source] Multicentre study of detection and false-negative rates in sentinel node biopsy for breast cancerBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 12 2001Dr L. Bergkvist Background: Sentinel node biopsy has recently evolved as a means of staging the axilla in breast cancer with minimal surgical trauma. The aim of this prospective multicentre study was to identify factors that influencd the detection and false-negative rates during the learning phase. Methods: Data on all 498 sentinel node biopsies performed between August 1997 and December 1999 in Sweden were collected. Results: A sentinel node was found in 450 patients (90 per cent). Preoperative scintigraphy visualized 83 per cent of all sentinel nodes. The detection rate was higher with same-day injection of tracer than with injection the day before (96 versus 86 per cent; P < 0·01). Dye injected less than 5 min or more than 30 min before the start of the operation lowered the detection rate (less than 60 per cent versus more than 65 per cent; P = 0·02). The detection rate varied from 61 to 100 per cent between surgeons. The false-negative rate was 11 per cent. The presence of multiple tumour foci and a high S-phase fraction increased the risk of a false-negative sentinel node, whereas the number of operations performed by each surgeon was less important. Conclusion: Training of the individual surgeon influenced the detection rate, as did timing of tracer and dye injection. The false-negative rate seemed to be related to biological factors. © 2001 British Journal of Surgery Society Ltd [source] Internal Sinus Manipulation (ISM) Procedure: A Technical ReportCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2007Jason M. Yamada DDS ABSTRACT Background, The sinus augmentation procedure has facilitated dental implant treatment in the posterior maxilla where there is insufficient bone for implant placement. A modified Caldwell-Luc, lateral window technique can be applied in most cases needing sinus augmentation in order to create a larger bone volume. However, treatment morbidity can be a concern, especially in the form of postoperative swelling due to surgical trauma. Vertical augmentation using osteotomes has also been selected as a choice of treatment due to less invasive surgery and less postoperative trauma. Although the osteotome technique enables the surgeon to raise the sinus membrane internally through an implant osteotomy site, the quantity and predictability of bone augmentation can be limiting due to the elasticity of the Schneiderian sinus membrane, difficulty of the membrane to separate from the floor as well as the inability to have direct tactile access to "peel" the membrane off of the floor. Purpose, The objective of this report is to present a new, minimally invasive sinus augmentation technique, called the Internal Sinus Manipulation (ISM) procedure, which has been developed to facilitate sinus floor augmentation while reducing treatment morbidity and yet have direct tactile access to raise the membrane off of the sinus floor. Surgical Technique, Access to the Schneiderian sinus membrane is achieved without perforation of the membrane through a conventional osteotomy drilling procedure alone or combined with osteotome technique, followed by reflection of the membrane utilizing special ISM instrumentation and bone graft procedure laterally and vertically through the osteotomy site. A planned implant is then placed. Conclusion, The Internal Sinus Manipulation procedure can be used as an alternative treatment modality for sinus augmentation as compared to the external lateral window technique while reducing postoperative morbidity for the patients who need implant treatment in posterior maxillary areas. [source] Influence of preimplant surgical intervention and implant placement on bone wound healingCLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2003Christer Slotte Abstract: The aims of the present investigation were to study (1) the influence of preimplant (4 weeks) surgical intervention and (2) the influence of the implant placement per se on bone density and mineralized bone,implant contact (BIC) at implant sites in the rabbit jawbone. The experiment was performed in the edentulous area of the maxillas of 16 adult rabbits. In eight rabbits, the alveolar bone on the left side (test) was surgically exposed and a groove was prepared in the bone crest. Trabecular bone and marrow tissue were removed, and a bioabsorbable barrier membrane was placed to cover the groove. The right side underwent no treatment and served as the control. Four weeks later, a screw-shaped titanium implant was placed transversally through the maxilla, penetrating both the test and the control areas. After another 4 weeks of healing, the animals were killed to obtain ground sections for histomorphometry. Untreated jaws from eight rabbits served as reference specimens. In the rabbits subjected to surgery, the areas (mm2) of both mineralized bone and marrow tissue were similar for test and control (4.9 ± 1.7 vs. 5.1 ± 2.2 and 6.3 ± 5.7 vs. 6.8 ± 5.7 for bone and marrow, respectively). The BIC (%) for all threads was significantly lower on the test side than on the control side (32.1 ± 27.7 vs. 47.7 ± 20.3). The bone density (%) of the total experimental area was similar for test and control (48.5 ± 12.1 vs. 46.5 ± 9.3), as was the bone density in the area within the implant thread valleys and their mirror areas (43.0 ± 13.9 vs. 41.3 ± 13.5, and 40.2 ± 11.0 vs. 40.3 ± 7.2 for thread area and mirror area, respectively). The bone density of the total experimental area in the untreated rabbits was 35.9 ± 5.2%. This value was significantly lower than the values in the total experimental areas (test and control) of the surgically treated rabbits. Similarly, the density of the reference area in the untreated rabbits was 25.4 ± 5.3%, which was also significantly lower than the bone density of the periimplant area of the surgically treated rabbits. We conclude that the surgical trauma caused by the placement of implants in the maxilla of rabbits significantly enhanced the bone density of the implant sites. Surgical intervention in the implant sites 4 weeks prior to the implant placements, however, did not further enhance bone density or BIC. Résumé Les buts de cette étude ont été d'étudier 1) l'influence d'une intervention chirurgicale préimplantaire (4 semaines) et 2) l'influence du placement de l'implant per se sur la densité osseuse et le contact implant-os minéralisé (BIC). Cette expérience a été effectuée dans la région édentée du maxillaire de seize lapins adultes. Chez huit lapins, l'os alvéolaire du côté gauche (test) était chirurgicalement exposé et une marque a été faite dans la crête osseuse. L'os trabéculaire et le tissu spongieux ont été enlevés et une membrane biorésorbable a été placée pour couvrir ce trou. Le côté droit ne subissait aucun traitement et a servi de contrôle. Quatre semaines après, un implant en titane vis a été placé transversalement à travers le maxillaire pénétrant tant la zone test que contrôle. Après quatre semaines de guérison les animaux ont été tués pour obtenir des coupes pour l'histomorphométrie. Les mâchoires non-traitées de huit lapins ont servi de spécimens de référence. Chez les lapins soumis à la chirugie les zones d'os minéralisé et de tissu spongieux étaient semblables pour le test et le contrôle (respectivement 4,9±1,7 mm2 vs 5,1±2,2 mm2 et 6,3±5,7 mm2 vs 6,8±5,7mm2). Les BIC pour tous les filetages étaient significativement moins importants au niveau des tests que des contrôles (32,1±27,7% vs 47,7±20,3%). La densité osseuse du total de l'aire expérimentale était semblable pour les tests et les contrôles (48,5±12,1%vs 46,3±9,3%) comme l'était la densité osseuse dans la zone à l'intérieur du filetage de l'implant et de leurs aires mineures (43,0±13,9%vs 41,3±13,5% pour les filetages et 40,2±11,0% vs40,3±7,2% pour les aires mineures). La densité osseuse de l'aire expérimentale totale chez les lapins nont-traités était de 35,9 ±5,2%. Cette valeur était significativement inférieure à celles dans les aires expérimentales totales (tests et contrôles) des lapins traités chirurgicalement. Parallèlement, la densité de l'aire de référence des lapins non-traités était de 25,4±5,3% c.-à-d. inférieure à la densité osseuse de la zone paroïmplantaire des lapins traités chirurgicalement. Le trauma chirurgical causé par le placement d'implants dans le maxillaire de lapins augmente significativement la densité osseuse au niveau des sites implantaires. L'intervention chirurgicale des sites à implanter quatre semaines avant le placement des implants n'avait cependant augmenté ni la densité osseuse ni le BIC. Zussammenfassung Der Einfluss eines praeimplantären chirurgischen Eingriffes und der Implantation per se auf die Heilung der Knochenwunde. Eine Studie am Kieferknochen des Kaninchens. Ziel: Das Ziel dieser Studie war es 1) den Einfluss eines praeimplantären chirurgischen Eingriffes (4 Wochen vorher) und 2) den Einfluss der Implantation per se auf die Knochendichte und den mineralisierten Knochen-Implantatkontakt (BIC) an einer Implantationsstelle im Kieferknochen des Kaninchens zu untersuchen. Material und Methode: Die Testregion war der zahnlose Oberkieferabschnitt von 16 ausgewachsenen Kaninchen. Bei 8 Kaninchen wurde der Alveolarknochen der linken Seite (Test) chirurgisch freigelegt und eine Vertiefungen in den Knochenkortex präpariert. Dann entfernte man den trabekulären Knochen und das Knochenmark und deckte die Vertiefung mit einer bioresorbierbaren Membran ab. Die rechte Seite wurde unbehandelt belassen und diente als Kontrolle. Vier Wochen später implantierte man ein schraubenförmiges Titanimplantat transversal durch die Maxilla, so dass es Test- oder Kontrollregion durchdrang. Nach einer Heilphase von weiteren vier Wochen wurden die Tiere geopfert und von der zu untersuchenden Region Grundschnitte für die Histologie hergestellt. Als Referenz dienten unbehandelte (jungfräuliche) Kiefer von weiteren 8 Kaninchen. Resultate: Bei den Kaninchen, welche die oben beschriebenen chirurgischen Schritte durchlaufen haben, waren sowohl bei der Test- wie auch bei der Kontrollgruppe die Fläche von mineralisiertem Knochen und Knochenmark (in mm2) ähnlich gross (4.9+1.7 gegenüber 5.1+2.2 beim Knochen und 6.3+5.7 gegenüber 6.8+5.7 beim Knochenmark). Der BIC (%) war in allen Schraubenwindungen auf der Testseite signifikant tiefer als auf der Kontrollseite (32.1+27.7 gegenüber 47.7+20.3). Die Knochendichte (%) war in der untersuchten Region bei der Test- und Kontrollseite etwa gleich gross (48.5+12.1 gegenüber 46.5+9.3) wie die Knochendichte in den Vertiefungen der Schraubenwindungen und ihrer spiegelbildlichen Regionen (43.0+13.9 gegenüber 41.3+13.5 in den Schraubenwindungen und 40.2+11.0 gegenüber 40.3+7.2 in den spiegelbildlichen Regionen). Die Knochendichte in der gesamten Region der unbehandelten (jungfräulichen) Kaninchen betrug 35.9+5.2%. Dieser Wert war signifikant tiefer als die Werte der gesamten untersuchten Region der chirurgisch behandelten Kaninchen (Test- und Kontrollseite). Ganz ähnlich war die Dichte in der Referenzregion der unbehandelten Kaninchen 25.4+5.3%, ein Wert der auch signifikant tiefer war als die Knochendichte in der periimplantären Region von chirurgisch behandelten Kaninchen. Zusammenfassung: Das chirurgische Trauma, das beim Setzen eines Implantates im Oberkiefer von Kaninchen entsteht, begünstigt die Knochendichte an den Stellen der Implantate signifikant. Der chirurgischen Eingriff vier Wochen vor der Implantation jedoch, förderte an den zur Implantation vorgesehenen Stellen weder Knochendichte noch BIC. Resumen Objetivos: La intención de la presente investigación fue estudiar 1) la influencia de la intervención quirúrgica (4 semanas) periimplantaria y 2) la influencia de la colocación de implantes per se en la densidad ósea y el contacto del hueso mineralizado al implante (BIC) en los lugares de implante en el hueso mandibular del conejo. Material y métodos: El experimento se realizó en el área edéntula del maxilar de 16 conejos adultos. Se expuso quirúrgicamente el hueso alveolar en el lado izquierdo (test) de 8 conejos y se preparó un hueco en la cresta ósea. Se retiró el hueso trabecular y el tejido de médula ósea, colocándose una membrana de barrera biorreabsorbible para cubrir el hueco. El lado derecho no sufrió ningún tratamiento y sirvió de control. Cuatro semanas mas tarde, se colocó un implante de forma roscada transversalmente a través del maxilar, penetrando las áreas de prueba y de control. Tras otras 4 semanas de cicatrización, los animales se sacrificaron para obtener cortes histológicos para histomorfometría. Las mandíbulas sin tratar de los 8 conejos sirvieron como especímenes de referencia. Resultados: En los conejos sometidos a cirugía las áreas (mm2) del hueso mineralizado y del tejido medular fueron similares para la prueba y el control (4.9 ± 1.7 vs. 5.1 ± 2.2 y 6.3 ± 5.7 vs. 6.8 ± 5.7, hueso y médula respectivamente). El BIC (%) para todas las roscas fue significativamente mas bajo en el lado de prueba que en el de control (32.1 ± 27.7 vs. 47.7 ± 20.3). La densidad de ósea (%) de toda el área experimental fue similar para la prueba y el control (48.5 ± 12.1 vs. 46.5 ± 9.3) así como la densidad ósea en el área en los valles entre las roscas y en su área espejo (43.0 ± 13.9 vs. 41.3 ± 13.5, y 40.2 ± 11.0 vs. 40.3 ± 7.2, área de roscas y área espejo respectivamente). La densidad ósea en el área total experimental en los conejos no tratados (vírgenes) fue del 35.9 ± 5.2%. Este valor fue significativamente mas bajo que los valores en el total de las áreas experimentales (test y control) de los conejos tratados quirúrgicamente. Del mismo modo, la densidad del área de referencia de los conejos no tratados fue de 25.4 ± 5.3%, que también fue significativamente mas baja que la densidad ósea del área periimplantaria de los conejos tratados quirúrgicamente. Conclusión: El trauma quirúrgico causado por la colocación de implantes en el maxilar de conejos estimuló significativamente la densidad ósea de los lugares de implantes. Sin embargo, la intervención quirúrgica de los lugares de implantes 4 semanas antes de la colocación de los implantes no estimuló mas la densidad ósea o el BIC. [source] | |||||||||||||