Periosteal Microcirculation Research Articles

Examination of Local Periosteal Microcirculation After Application of Absorbable and Nonabsorbable Membranes.

The use of different membranes is common in dentoalveolar surgery. Absorbable and nonabsorbable membranes are used, often beneath the periosteum, to fulfil different functions (as barriers, patches, or spacers). It is still unclear to what extent such membranes affect the biology of the periosteum and what role is played by piezoelectric devices during preparation of the periosteum. We placed two different membranes (absorbable and nonabsorbable) underneath the periosteum of rat calvaria. We prepared the periosteum using different methods (piezoelectric device vs mechanical device). We then examined and analyzed periosteal microcirculation over a period of 28 days. A clear difference was observed between the two methods when used with absorbable membranes: The piezoelectric device offered advantages. Absorbable membranes maintain considerably more local periosteal microcirculation and should be given preference. In addition, we observed an advantage to using a piezoelectric device for periosteal dissection. Therefore, this method should also be used more widely.

Estrogen-dependent efficacy of limb ischemic preconditioning in female rats.

Our aim was to examine the effects of ischemic preconditioning (IPC) on the local periosteal and systemic inflammatory consequences of hindlimb ischemia-reperfusion (IR) in Sprague-Dawley rats with chronic estrogen deficiency (13 weeks after ovariectomy, OVX) in the presence and absence of chronic 17beta-estradiol supplementation (E2, 20 µg kg-1 , 5 days/week for 5 weeks); sham-operated (non-OVX) animals served as controls. As assessed by intravital fluorescence microscopy, rolling and the firm adhesion of polymorphonuclear neutrophil leukocytes (PMNs) gave similar results in the Sham + IR and OVX + IR groups in the tibial periosteal microcirculation during the 3-h reperfusion period after a 60-min tourniquet ischemia. Postischemic increases in periosteal PMN adhesion and PMN-derived adhesion molecule CD11b expressions, however, were significantly reduced by IPC (two cycles of 10'/10') in Sham animals, but not in OVX animals; neither plasma free radical levels (as measured by chemiluminescence), nor TNF-alpha release was affected by IPC. E2 supplementation in OVX animals restored the IPC-related microcirculatory integrity and PMN-derived CD11b levels, and TNF-alpha and free radical levels were reduced by IPC only with E2. An enhanced estrogen receptor beta expression could also be demonstrated after E2 in the periosteum. Overall, the beneficial periosteal microcirculatory effects of limb IPC are lost in chronic estrogen deficiency, but they can be restored by E2 supplementation. This suggests that the presence of endogenous estrogen is a necessary facilitating factor of the anti-inflammatory protection provided by limb IPC in females. The IPC-independent effects of E2 on inflammatory reactions should also be taken into account in this model. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:97-105, 2018.

Effects of a new piezoelectric device on periosteal microcirculation after subperiosteal preparation

IntroductionSubperiosteal preparation using a periosteal elevator leads to disturbances of local periosteal microcirculation. Soft-tissue damage can usually be considerably reduced using piezoelectric technology. For this reason, we investigated the effects of a novel piezoelectric device on local periosteal microcirculation and compared this approach with the conventional preparation of the periosteum using a periosteal elevator. Material and methodsA total of 20 Lewis rats were randomly assigned to one of two groups. Subperiosteal preparation was performed using either a piezoelectric device or a periosteal elevator. Intravital microscopy was performed immediately after the procedure as well as three and eight days postoperatively. Statistical analysis of microcirculatory parameters was performed offline using analysis of variance (ANOVA) on ranks (p<0.05). ResultsAt all time points investigated, intravital microscopy demonstrated significantly higher levels of periosteal perfusion in the group of rats that underwent piezosurgery than in the group of rats that underwent treatment with a periosteal elevator. ConclusionThe use of a piezoelectric device for subperiosteal preparation is associated with better periosteal microcirculation than the use of a conventional periosteal elevator. As a result, piezoelectric devices can be expected to have a positive effect on bone metabolism.

Periosteal microvascular reorganization after tibial reaming and intramedullary nailing in rats

BackgroundIntramedullary reaming and nailing of long bones impairs the endosteal circulation, often causing necrosis of the inner region of the bone cortex. We hypothesized that compensatory hypertrophy of the periosteal microcirculation may develop in response to mechanical destruction of the endosteum, and that this may affect bone survival in these circumstances. In these studies, nailing was performed with materials that affect regeneration of the endosteum differently, and the effects on the tibial periosteal microvasculatory organization were examined. MethodsIn male Wistar rats, the right tibia was reamed and implanted with an inert titanium nail or a less osseointegrative polyethylene nail; the contralateral tibial endosteum was destroyed by reaming. Reaming without nailing or sham operation was performed on both extremities in two other groups of rats. Twelve weeks later, the anteromedial and anterolateral surfaces of the tibias were exposed by a microsurgical technique. The structural characteristics of the periosteal microcirculation (vessel density and distribution of vessel diameters) were determined by intravital videomicroscopy and computer-assisted analysis. The stability of the implants was assessed on the basis of grades 0–2 on a qualitative scale. ResultsTibial reaming alone caused significant increases in overall blood vessel and capillary densities in the periosteum compared with those of the intact tibias. Implantation with a titanium nail resulted in firm embedding of the nail and caused changes in the periosteal vasculature similar to those after reaming alone. In contrast, implantation of a polyethylene nail was followed by the development of marked instability of the endomedullary implant and significant increases in the percentage of capillaries and the vessel density in the periosteum. ConclusionsDestruction of the endosteal microcirculation per se brings about an increase in periosteal vascular density, which is further augmented if implantation is performed with a material which delays regeneration of the endosteal circulation.

Limb ischemia–reperfusion differentially affects the periosteal and synovial microcirculation

BackgroundJoints are privileged compartments that enjoy increased protection against the inflammatory reactions affecting the extremities. We hypothesized that the functional characteristics of the microvasculature would contribute to the differential defensive potential of the synovial membrane. MethodsWe investigated the synovial microcirculatory reactions and compared them with those of the tibial periosteum in response to 60 min of total limb ischemia, followed by 180 min of ischemia–reperfusion (IR) in rats. Carrageenan/kaolin-induced knee monoarthritis, a neutrophil-driven synovial inflammation model, served as the positive control. ResultsIR brought about a significant reduction in red blood cell velocity in the capillaries and increases in rolling and adherence of the neutrophil leukocytes in the postcapillary venules (intravital microscopy), in adhesion molecule expression (intercellular adhesion molecule-1 immunohistochemistry) and in xanthine oxidoreductase activity in the periosteum. These changes were also pronounced in carrageenan/kaolin-induced monoarthritis but were almost completely absent in the synovium after the IR challenge. Most importantly, even after IR and in carrageenan/kaolin monoarthritis, the synovial microcirculation was characterized by significantly greater red blood cell velocities than that in the periosteum under resting conditions. ConclusionsThe ischemic duration, which significantly affected the functional integrity of the periosteal microcirculation, did not bring about a marked deterioration in that of the synovial membrane, suggesting that the synovial microcirculation is less endangered to the consequences of short-term tourniquet exposure than the periosteum. The greater microcirculatory red blood cell velocities and lower IR-induced endothelial expression of intercellular adhesion molecule-1 in the synovial membrane might explain the greater resistance of this compartment to the inflammatory consequences of IR.

A new model for chronic in vivo analysis of the periosteal microcirculation

Objective Microvascular perfusion is indispensable for the growth and remodulation of membrane bone. Trauma, inflammation and surgical interventions may alter periosteal perfusion. However, there is not much known about periosteal perfusion in membrane bones. Therefore, the aim of this study was to establish a new chronic model that permits the repeated in vivo analysis of the microcirculation of periosteum. Methods A circular skin island with a diameter of 6 mm was excised at the forehead of six Lewis rats. Then a newly developed chamber was implanted, containing a coverglass to protect the periosteum. Intravital microscopy (IVM) enables a quantitative analysis of periosteal microcirculation immediately as well as 3, 5 and 10 days after chamber implantation. At the end of the experiment the calvaria and periosteum were removed for histological examination. Six unoperated Lewis rats served as histological controls. Results The periosteal microcirculation remained stable over 10 days. The implantation of the chamber did not result in any substantial inflammatory response. The functional microvascular density was 131.2 ± 19.3 cm/cm 2. The histological examinations revealed a regular anatomical structure of periosteum and bone including an intact interface. Conclusion The presented model allows for the first time to conduct a repetitive, quantitative in vivo analysis of the periosteal microcirculation in membrane bone. Future studies may thus evaluate novel strategies to influence the periosteal perfusion.

Beneficial Effects of Phosphatidylcholine During Hindlimb Reperfusion

Microcirculatory dysfunctions and mast cell (MC) reactions play important roles in hypoxic tissue injuries. The aims of this study were to characterize the effects of hindlimb ischemia-reperfusion (I-R) on the periosteal microcirculation and to define the consequences of systemic phosphatidylcholine (PC) therapy during this condition. Microcirculatory changes were visualized by means of fluorescence intravital videomicroscopy in anesthetized Wistar rats. There was 60 min of complete hindlimb ischemia followed by a 180-min reperfusion in the presence of PC treatment (50 mg/kg i.v.; in the second 10 min of reperfusion) or vehicle. Further two groups served as vehicle- or PC-treated sham-operated controls. The proportion of degranulated MCs and the leukocyte accumulation (myeloperoxidase, MPO assay) were determined in muscle biopsies. I-R significantly increased the muscle MPO activity (from 14.94 to 63.45 mU/mg) and the proportion of degranulated MCs (to 82.5%). The periosteal capillary RBC velocity (RBCV) and the functional capillary density (FCD) had decreased, while the primary and secondary leukocyte-endothelial cell interactions had increased by the end of reperfusion (rolling from 20.8 to 40.0%, and firm adherence from 254 to 872 mm(-2)). PC treatment decreased the leukocyte rolling and sticking, preserved the FCD and improved the RBCV. The MC degranulation and MPO activity diminished significantly in the muscle layer. PC administration improves I-R-induced periosteal microcirculatory dysfunctions and ameliorates secondary inflammatory reactions. Systemic PC treatment could offer a potential treatment modality during hypoperfusion or inflammatory conditions of the bones.

Temporal profile of microvascular disturbances in rat tibial periosteum following closed soft tissue trauma.

Bone devascularization due to impaired periosteal perfusion following fracture with severe soft tissue trauma has been proposed to precede and underlie perturbed bone healing. The extent and temporal relationship of periosteal microcirculatory deteriorations after severe closed soft tissue injury (CSTI) are not known. We hypothesized that periosteal microcirculation is adversely affected and the manifestation of trauma-initiated microvascular impairment in periosteum is substantially prolonged following CSTI. Using the controlled-impact injury device, we induced standardized CSTI in the tibial compartment of 35 isoflurane-anesthetized rats. Following the trauma the rats were assigned to five groups, differing in time of analysis (2 h, 24 h, 48 h, 1 and 6 weeks). Non-injured rats served as controls. Before the metaphyseal/diaphyseal periosteum was surgically exposed, intramuscular pressure within tibial compartment was measured. Using intravital fluorescence microscopy (IVM) we studied the microcirculation of the tibial periosteum. We calculated the edema index (EI) by measuring the skeletal muscle wet-to-dry weight ratio (EI = injured limb/contralateral limb). Microvascular deteriorations of periosteal microhemodynamics caused by isolated CSTI were reflected by persistent decrease in nutritive perfusion, markedly prolonged increase in microvascular permeability associated with increasingly sustained leukocyte rolling and adherence throughout the entire study period, mostly pronounced 48 h after the trauma. Peak level in capillary leakage coincided with the maximum leukocyte adherence, tissue pressure, and edema. Microcirculation of tibial periosteum in control rats demonstrated a homogeneous perfusion with no capillary or endothelial dysfunction. Isolated CSTI in absence of a fracture exerts long-lasting disturbances in periosteal microcirculation, suggesting a delayed temporal profile in manifestation of CSTI-induced periosteal microvascular dysfunction and inflammation. These observations may have therapeutic implications in terms of preserving periosteal integrity and considering the interaction of skeletal muscle damage and periosteal microvascular injury during management of musculoskeletal trauma.

Endothelin-a receptor antagonist treatment improves the periosteal microcirculation after hindlimb ischemia and reperfusion in the rat.

To examine the microcirculatory changes in the rat tibial periosteum after hindlimb ischemia and reperfusion and to evaluate the effects of endothelin-A (ET-A) receptor antagonist therapy in this condition. The healing and functioning of vascularized bone autografts depend mainly on the patency of the microcirculation, and the activation of ET-A receptors may be an important component of the tissue response that occurs during ischemia-reoxygenation injuries. Wistar rats were subjected to 1 hour of hindlimb ischemia and 3 hours of reperfusion. The periosteal microcirculation was visualized by intravital fluorescence microscopy. The leukocyte rolling and adherence in the postcapillary venules and the functional capillary density of the periosteum were determined. Two separate groups were treated with the selective ET-A receptor antagonist BQ 610 or the novel ET-A receptor antagonist ETR-p1/fl peptide at the onset of reperfusion. Reperfusion was accompanied by a significant decrease in functional capillary density and by an increase in the primary and secondary leukocyte-endothelial cell interactions. ET-A receptor inhibition reduced the leukocyte rolling and firm adherence and attenuated the decrease in functional capillary density in both treated groups. ET-1 plays a major role in microvascular dysfunction in the periosteum during reperfusion. The ET-1-ET-A receptor system might be an important target for tissue salvage therapy in transplantation surgery.

Endothelin-A Receptor Antagonist Treatment Improves the Periosteal Microcirculation After Hindlimb Ischemia and Reperfusion in the Rat

Endothelin-A Receptor Antagonist Treatment Improves the Periosteal Microcirculation After Hindlimb Ischemia and Reperfusion in the Rat

Endothelin-A Receptor Antagonist Treatment Improves the Periosteal Microcirculation After Hindlimb Ischemia and Reperfusion in the Rat

Endothelin-A Receptor Antagonist Treatment Improves the Periosteal Microcirculation After Hindlimb Ischemia and Reperfusion in the Rat

Pericytes as a Supplementary Source of Osteoblasts in Periosteal Osteogenesis

In the adult rat femur, lifting a periosteum strip with microscopic bone flakes on its deep surface, if performed without damaging the surrounding microcirculation, rapidly leads to new bone formation and angiogenesis. Using vascular labeling, the pericytes and endothelial cells (ECs) were labeled with monastral blue (MB) in the preformed, preexisting postcapillary venules of the periosteal microcirculation. MB was detectable by light and electron microscopy and it persisted in some of the daughter cells. Between one and 21 hours, the MB labeling was restricted to the pericytes and ECs of postcapillary venules. Immediately afterward, both pericytes and ECs of these vessels were activated and continued to show MB. The phenomenon of pericyte activation includes enlargement, disruption of their basal lamina, separation from the walls of the preformed vessels, and the presence of mitotic figures. At this stage, activated pericytes with MB in their cytoplasm, fibroblast-like cells, and transitional cell forms between them were seen in interstitial areas. After 27 hours, vascular buds appeared and MB was detected in some ECs and pericytes. Between three and six days, when bone-tissue development was observed, some osteoblasts were MB labeled. Previous findings support the hypothesis that when the periosteum is activated, the process of bone formation from cells already present in the periosteum is augmented by proliferation and differentiation of pericytes, which contribute a supplementary population of osteoprogenitor cells.