Spinal epidural fibrosis following hemostatic agent employment.

OBJECTIVE: Failed Back Surgery Syndrome (FBSS) refers to a subset of patients who have new or persistent pain after spinal surgery for back or leg pain. Epidural fibrosis (EF) is a common cause of FBSS. Many agents aiming to prevent EF have been tested. However, hemostatic agents are readily available at hospitals, easy to reach and frequently used. For these reasons, oxidized regenerated cellulose, polysaccharide hemostat, hemostatic thrombin-gelatin matrix and chitosan linear polymer were evaluated for their effects on epidural fibrosis on rats after laminectomy. METHODS: 40 Sprague-Dawley rats were randomly divided into 5 equal groups including the control group where only the laminectomy was performed. The other 4 groups received hemostatic agents after laminectomy. The rats were euthanized 45 days later and were assessed by a blinded observer to grade the fibrosis level. RESULTS: The study revealed that oxidized regenerated cellulose, polysaccharide hemostat and hemostatic thrombin-gelatin matrix lowered the epidural fibrosis grade which was statistically significant (p < 0.001). Although chitosan linear polymer created fibrosis similar to the control group it was not proven to be statistically significant (p = 0.8999). However, when compared with other hemostatic agents it resulted in a higher fibrosis grade (p < 0.001). CONCLUSION: The results obtained from this experimental study revealed that Pahacel, Sealfoam and Surgiflo, were effective in reducing epidural fibrosis after laminectomy in rats.

Corticosteroid pre-treated primary CNS lymphoma: a detailed analysis of stereotactic biopsy findings and consideration of interobserver variability.

Prior corticosteroid therapy presents a major challenge in the diagnosis of CNS lymphomas, particularly in stereotactic biopsies. In this study we analysed the cytological, histopathological and immunohistochemical features in stereotactic biopsies of 25 primary CNS lymphoma cases pre-treated with corticosteroids. We documented the extent and the frequency of each finding. We also investigated the significance of subjectivity in evaluation of these biopsies in 3 seperate sessions including the final diagnostic decision. In 48% of our cases the diagnosis was straightforward. These cases were characterized by prominent blasts either in diffuse paranchymal infiltrates or in perivascular regions. The remaining 52% demonstrated some degree of variability among pathologists. Lymphoid atypia other than the typical blastic morphology appeared as a subjective finding and this was more pronounced in cytology preparations. In our study, corticosteroid pre-treatment in primary CNS lymphoma was associated with a large spectrum of histopathological, immunohistochemical and cytological findings. Combined use of an extended immunohistochemical panel would increase the possibility of conclusive diagnosis. Nevertheless some of these findings and therefore the diagnosis are open to subjectivity.

The preventive role of transurethral antibiotic delivery in a rat model.

PURPOSE: There is currently an emerging need for developing improved approaches for preventing urinary tract infections (UTIs) occurring during diagnostic or interventional procedures of the lower urinary tract. We aimed to establish a rat model to assess the use of transurethral antibiotic administration and to provide evidence that this could be used as a preventive therapy. METHODS: Animals received fosfomycin trometamol (FOF) either urethrally or orally prior to the procedure. A third group was generated as treatment controls and did not receive any medication. Urethral dilation was conducted to recapitulate an interventional procedure prior to intravesical Escherichia coli administration in all three groups. Finally, sham-operated animals were introduced as a fourth group which did not receive antibiotics or E. coli. Colony counts of urine and tissue cultures for the identification of E. coli and histopathological examinations of the bladder and prostate were conducted. RESULTS: Evaluation of infection intensities in cultures as well as histopathological examination of the bladder and prostate demonstrated a preventative role of transurethral FOF administration. In terms of efficiency, local administration of FOF was similar to oral administration. CONCLUSIONS: These results suggest that transurethral antibiotic administration is a promising alternative for preventing UTIs occurring during diagnostic or interventional procedures of the lower urinary tract.