Preoperative administration of local infiltration anaesthesia decreases perioperative blood loss during total knee arthroplasty - a randomised controlled trial.

PURPOSE: Local infiltration anaesthesia (LIA) consisting of ropivacaine, epinephrine and ketorolac administered at the end of surgery has become the gold standard for postoperative analgesia as it provides improved postoperative pain relief compared to other methods. The use of LIA has retrospectively been shown to be associated with decreased perioperative blood loss. However, no randomised controlled trials have examined the effect of of preoperative LIA on blood loss. This study aimed to compare pre- vs perioperative LIA during TKA surgery, with a primary outcome of perioperative blood loss. METHODS: The present study was performed as a prospective single-center randomised controlled trial. A total of 100 patients undergoing primary TKA between October 2016 and March 2018 were randomised to receive either pre- or perioperative LIA. Perioperative blood loss was measured, as well as pre- and postoperative haemoglobin levels. Postoperative pain was estimated at intervals approximately 24, 48 and 72 hours after surgery; analgesic drug consumption was recorded for each patient, as well as the total length of stay as an in-patient. RESULTS: Ninety six patients received either pre- or perioperative LIA as part of the intervention and control group respectively. Average blood loss was 39% lower in the intervention group at 130 ml vs 212 ml in the control group (p=0.002). No significant difference in haemoglobin drop, postoperative pain or length of hospital stay was found. CONCLUSIONS: Preoperative LIA resulted in a 39% decrease in perioperative blood loss during TKA surgery compared to perioperative administration while providing non-inferior postoperative pain relief.

Autologous semitendinosus tendon graft could function as a meniscal transplant.

PURPOSE: Meniscectomy results in poor knee function and increased risk for osteoarthritis. Meniscal allograft transplantation is not widely used due to costs and availability. The semitendinosus tendon (ST) has the potential to remodel and revascularize in an intraarticular environment, such as ACL reconstruction. The objective for this pilot study was to investigate whether the ST graft could function as a meniscal transplant. METHODS: The ST was doubled and sutured with running sutures and pull-out sutures in each end. Bone tunnels were used for root anchorage and the graft was sutured with allinside, inside-out and outside-in technique. The pull-out sutures were fixed over a button. Partial weight bearing was allowed with limited range of motion in a brace for the first 6 weeks. Evaluation was assessed using clinical examination, radiology and patient reported outcome. RESULTS: A total of seven patients have been included between January 2018 and June 2020. Six medial transplants and one lateral transplant were performed. Mean age was 29 years. Four patients had completed the 12-month follow-up. Improvements were noted for IKDC Global Score, KOOS pain subscale and Lysholm. MRI indicated that the transplant become more wedge-like with visible roots and minor protrusion. CONCLUSIONS: Even though this is primarily a technical report the follow-up data indicate that the transplant survives and adapts in shape and capabilities to an original meniscus. There were no adverse events and the patients seem to improve in terms of pain and quality of life.

Increased mortality among patients with diabetes following first-ever transfemoral amputation.

AIMS: Transfemoral amputation (TFA) is associated with a high postoperative mortality though it is unclear whether diabetes is associated with an increased mortality or not. The aim was to examine mortality at 1 week and 1 year after first-ever TFA with special reference to diabetes. METHODS: We included 162 first-ever TFAs from 1996 to 2012. Mortality data were collected with the use of the Swedish personal identification number. RESULTS: The median age was 85 years. Diabetes mellitus were present in 19% (n = 30) of the patients and 67% (n = 109) had cardiovascular disease. Mortality was significantly higher for patients with diabetes compared to patients without diabetes at 1 week (30% vs. 8%, p = 0.001) and at 1 year (80% vs. 57%, p = 0.02). This difference was significant in multivariable analysis. CONCLUSIONS: We conclude that postoperative mortality was high. The high mortality rate emphasizes the need for early and adequate evaluation of every patient́s overall condition and whether amputation is beneficial or not. Although further studies are needed to analyze the specific causes of early death in amputees and we suggest close monitoring of blood-sugar in patients with diabetes and early treatment of infections and cardiac events in all patients.

Contribution of endothelial injury and inflammation in early phase to vein graft failure: the causal factors impact on the development of intimal hyperplasia in murine models.

OBJECTIVES: Autologous veins are preferred conduits in by-pass surgery. However, long-term results are hampered by limited patency due to intimal hyperplasia. Although mechanisms involved in development of intimal hyperplasia have been established, the role of inflammatory processes is still unclear. Here, we studied leukocyte recruitment and intimal hyperplasia in inferior vena cava grafts transferred to abdominal aorta in mice. METHODS AND RESULTS: Several microscopic techniques were used to study endothelium denudation and regeneration and leukocyte recruitment on endothelium. Scanning electron microscopy demonstrated denudation of vein graft endothelium 7 days post-transfer and complete endothelial regeneration by 28 days. Examination of vein grafts transferred to mice transgenic for green fluorescent protein under Tie2 promoter in endothelial cells showed regeneration of graft endothelium from the adjacent aorta. Intravital microscopy revealed recruitment of leukocytes in vein grafts at 7 days in wild type mice, which had tapered off by 28 days. At 28 and 63 days there was significant development of intimal hyperplasia. In contrast; no injury, leukocyte recruitment nor intimal hyperplasia occurred in arterial grafts. Leukocyte recruitment was reduced in vein grafts in mice deficient in E- and P-selectin. In parallel, intimal hyperplasia was reduced in vein grafts in mice deficient in E- and P-selectin and in wild type mice receiving P-selectin/E-selectin function-blocking antibodies. CONCLUSION: The results show that early phase endothelial injury and inflammation are crucial processes in intimal hyperplasia in murine vein grafts. The data implicate endothelial selectins as targets for intervention of vein graft disease.

Deletion of L-selectin increases atherosclerosis development in ApoE-/- mice.

Atherosclerosis is an inflammatory disease characterized by accumulation of leukocytes in the arterial intima. Members of the selectin family of adhesion molecules are important mediators of leukocyte extravasation. However, it is unclear whether L-selectin (L-sel) is involved in the pathogenesis of atherosclerosis. In the present study, mice deficient in L-selectin (L-sel(-/-)) animals were crossed with mice lacking Apolipoprotein E (ApoE(-/-)). The development of atherosclerosis was analyzed in double-knockout ApoE/L-sel (ApoE(-/-)L-sel(-/-)) mice and the corresponding ApoE(-/-) controls fed either a normal or a high cholesterol diet (HCD). After 6 weeks of HCD, aortic lesions were increased two-fold in ApoE(-/-)L-sel(-/-) mice as compared to ApoE(-/-) controls (2.46%±0.54% vs 1.28%±0.24% of total aortic area; p<0.05). Formation of atherosclerotic lesions was also enhanced in 6-month-old ApoE(-/-)L-sel(-/-) animals fed a normal diet (10.45%±2.58% vs 1.87%±0.37%; p<0.05). In contrast, after 12 weeks of HCD, there was no difference in atheroma formation between ApoE(-/-)L-sel(-/-) and ApoE(-/-) mice. Serum cholesterol levels remained unchanged by L-sel deletion. Atherosclerotic plaques did not exhibit any differences in cellular composition assessed by immunohistochemistry for CD68, CD3, CD4, and CD8 in ApoE(-/-)L-sel(-/-) as compared to ApoE(-/-) mice. Leukocyte rolling on lesions in the aorta was similar in ApoE(-/-)L-sel(-/-) and ApoE(-/-) animals. ApoE(-/-)L-sel(-/-) mice exhibited reduced size and cellularity of peripheral lymph nodes, increased size of spleen, and increased number of peripheral lymphocytes as compared to ApoE(-/-) controls. These data indicate that L-sel does not promote atherosclerotic lesion formation and suggest that it rather protects from early atherosclerosis.

Immune cell recruitment to inflammatory loci is impaired in mice deficient in basement membrane protein laminin alpha4.

For leukocytes to penetrate the vessel wall, they need to interact sequentially with the endothelial lining and the perivascular BM. The matrix protein laminin-411 is a major constituent of the vascular BM. The laminin alpha4 chain is a component of laminin-411 and has structural and signaling functions. Here, we addressed the role of BM laminin alpha4 in leukocyte recruitment to inflammatory loci. We used several recruitment models in Lam4(-/-) and WT mice to determine whether lack of laminin-411 in the perivascular BM influences extravasation of inflammatory cells. Recruitment of all major leukocyte subsets (neutrophils, monocytes, and lymphocytes) was reduced in Lam4(-/-) mice compared with WT. With the use of intravital microscopy, we concluded that this decrease was a result of impaired diapedesis through the vessel wall, as neither leukocyte adhesion to the endothelial lining nor migration in extravascular tissue was hampered in Lam4(-/-) mice. Collectively, our data suggest a reduced ability of immune cells to penetrate the vessel wall in mice deficient in laminin alpha4.

Distinct infiltration of neutrophils in lesion shoulders in ApoE-/- mice.

Inflammation and activation of immune cells are key mechanisms in the development of atherosclerosis. Previous data indicate important roles for monocytes and T-lymphocytes in lesions. However, recent data suggest that neutrophils also may be of importance in atherogenesis. Here, we use apolipoprotein E (ApoE)-deficient mice with fluorescent neutrophils and monocytes (ApoE(-/-)/Lys(EGFP/EGFP) mice) to specifically study neutrophil presence and recruitment in atherosclerotic lesions. We show by flow cytometry and confocal microscopy that neutrophils make up for 1.8% of CD45(+) leukocytes in the aortic wall of ApoE(-/-)/Lys(EGFP/EGFP) mice and that their contribution relative to monocyte/macrophages within lesions is approximately 1:3. However, neutrophils accumulate at sites of monocyte high density, preferentially in shoulder regions of lesions, and may even outnumber monocyte/macrophages in these areas. Furthermore, intravital microscopy established that a majority of leukocytes interacting with endothelium on lesion shoulders are neutrophils, suggesting a significant recruitment of these cells to plaque. These data demonstrate neutrophilic granulocytes as a major cellular component of atherosclerotic lesions in ApoE(-/-) mice and call for further study on the roles of these cells in atherogenesis.

ApoE(-/-)/lysozyme M(EGFP/EGFP) mice as a versatile model to study monocyte and neutrophil trafficking in atherosclerosis.

OBJECTIVES: Intravital microscopy is a useful tool for studying leukocyte trafficking in atherosclerosis. However, distinction between various subclasses of leukocytes using this technology is lacking. Therefore, we generated ApoE(-/-)/Lysozyme M(EGFP/EGFP) mice and investigated whether targeted cell types could be visualized by in vivo microscopy and whether absence of lysozyme M will influence atherosclerosis. METHODS: We crossed male ApoE(-/-) mice with mice homozygous for a knock-in mutation of enhanced green fluorescent protein (EGFP) in the lysozyme M locus (Lys(EGFP/EGFP)) creating ApoE(-/-)/Lys(EGFP/EGFP) mice. Mice were sacrificed at the age of 26 weeks. Blood was collected for serum lipid analysis, differential white blood cell count and flow cytometry. Lesion area was determined on en face mounted aortas and sections from aortic roots were stained for immunohistochemistry. Atherosclerotic lesions were also studied by confocal- and intravital microscopy. RESULTS: Basic parameters, such as white blood cell count, cholesterol profile, lesion area and plaque composition was unaltered in ApoE(-/-)/Lys(EGFP/EGFP) mice compared to ApoE(-/-) mice. Fluorescent neutrophils and monocytes were clearly visualized by intravital fluorescence and confocal microscopy. Fluorescent cells were distributed primarily in the periphery of atherosclerotic lesions indicating a preference for recruitment in these areas. CONCLUSIONS: ApoE(-/-)/Lys(EGFP/EGFP) mice will serve as a useful model to study leukocyte trafficking in atherosclerosis and how different subsets of leukocytes influence atherogenesis.

A novel class of potent nonglycosidic and nonpeptidic pan-selectin inhibitors.

An early step of the inflammatory response, the rolling of leukocytes on activated endothelial cells, is mediated by selectin/carbohydrate interactions. The tetrasaccharide sialy Lewisx is a ligand for E-, P-, and L-selectin and therefore serves as a lead structure for the development of analogues. A combination of synthesis and structure-based design allowed rapid optimization. The current lead 2a was evaluated in our E-selectin cell flow chamber assay where it proved to inhibit rolling and adhesion with an IC50 of 28+/-7 microM. The assays used are predictive for the in vivo efficacy of test compounds as shown for 2a in a proteose peptone induced peritonitis model of acute inflammation in mice.

Neutrophil-derived heparin-binding protein (HBP/CAP37) deposited on endothelium enhances monocyte arrest under flow conditions.

In acute inflammation, infiltration of neutrophils often precedes a second phase of monocyte invasion, and data in the literature suggest that neutrophils may directly stimulate mobilization of monocytes via neutrophil granule proteins. In this study, we present a role for neutrophil-derived heparin-binding protein (HBP) in monocyte arrest on endothelium. Adhesion of neutrophils to bovine aorta endothelial cells (ECs) or HUVEC-triggered secretion of HBP and binding of the protein to the EC surface. Blockade of neutrophil adhesion by treatment with a mAb to CD18 greatly reduced accumulation of HBP. In a flow chamber model, immobilized recombinant HBP induced arrest of human monocytes or monocytic Mono Mac 6 (MM6) cells to activated EC or plates coated with recombinant adhesion molecules (E-selectin, P-selectin, VCAM-1). However, immobilized recombinant HBP did not influence arrest of neutrophils or lymphocytes. Treatment of MM6 cells with recombinant HBP evoked a rapid and clear-cut increase in cytosolic free Ca(2+) that was found to be critical for the HBP-induced monocyte arrest inasmuch as pretreatment with the intracellular calcium chelating agent BAPTA-AM abolished the evoked increase in adhesion. Thus, secretion of a neutrophil granule protein, accumulating on the EC surface and promoting arrest of monocytes, could contribute to the recruitment of monocytes at inflammatory loci.

Powerful inflammatory properties of large vein endothelium in vivo.

OBJECTIVE: Inflammatory responses of large vein endothelium are of importance in pathological processes such as venous thrombosis, chronic venous congestion, and vein graft atherosclerosis. However, the inflammatory properties of large vein endothelium are unclear. METHODS AND RESULTS: In this study, we used several microscopy techniques to investigate the inflammatory properties of large vein endothelium in vivo. We show that the endothelium in the mouse inferior vena cava (IVC) possesses powerful inflammatory properties that are distinct from the less inflammatory reactive aortic endothelium and virtually identical to endothelial responses in postcapillary venules. Inflammatory stimulation with tumor necrosis factor-alpha induced strong expression of cell adhesion molecules (CAMs) in the IVC. These CAMs promoted recruitment of leukocytes, platelets, and erythrocytes to the vein wall. The inflammatory responses altered endothelial structure and increased endothelial permeability in the IVC. Accumulation of blood cells and endothelial damage were markedly reduced in mice deficient in the endothelial leukocyte recruitment molecules E-selectin and P-selectin, indicating a central role for these molecules in driving structural and functional changes of IVC endothelium. CONCLUSIONS: These findings provide the first comprehensive demonstration of the inflammatory capacity of large vein endothelium and emphasize the actions of endothelial cells as targets in large vein disease.