Postoperative surgical site infection in cholesteatoma surgery with and without mastoid obliteration, what can we learn?

INTRODUCTION: This study aims to describe the occurrence of postoperative complications related to cholesteatoma surgery and to determine factors influencing the most common complication, i.e. postoperative surgical site infection (SSI) in cases with and without mastoid obliteration. MATERIALS AND METHODS: Retrospective analyses were performed on surgically treated cholesteatomas in our hospital between 2013 and 2019. Patient characteristics, peri- and postoperative management and complications were reviewed. The cases were divided into two groups based on whether mastoid obliteration was performed or not. RESULTS: A total of 336 cholesteatoma operations were performed, of which 248 cases received mastoid obliteration. In total 21 complications were observed, of which SSI was the most common (15/21). No difference in occurrence of any postoperative complication was seen between the obliteration and no-obliteration group (p = 0.798), especially not in the number of SSI (p = 0.520). Perioperative and/or postoperative prophylactic antibiotics were not associated to the development of an SSI in both groups. In the no-obliteration group a younger age (p = 0.015), as well as primary surgery (p = 0.022) increased the risk for SSI. In the obliteration group the use of bioactive glass (BAG) S53P4 was identified as independent predictor of SSI (p = 0.008, OR 5.940). DISCUSSION: SSI is the most common postoperative complication in cholesteatoma surgery. The causes of SSI are multifactorial, therefore further prospective research is needed to answer which factors can prevent the development of an SSI in cholesteatoma surgery.

Raman spectroscopic analysis of the molecular composition of oral cavity squamous cell carcinoma and healthy tongue tissue.

A Raman tissue spectrum is a quantitative representation of the overall molecular composition of that tissue. Raman spectra are often used as tissue fingerprints without further interpretation of the specific information that they contain about the tissue's molecular composition. In this study, we analyzed the differences in molecular composition between oral cavity squamous cell carcinoma (OCSCC) and healthy tissue structures in tongue, based on their Raman spectra. A total of 1087 histopathologically annotated spectra (142 OCSCC, 202 surface squamous epithelium, 61 muscle, 65 adipose tissue, 581 connective tissue, 26 gland, and 10 nerve) were obtained from Raman maps of 44 tongue samples from 21 patients. A characteristic, average spectrum of each tissue structure was fitted with a set of 55 pure-compound reference spectra, to define the best library of fit-spectra. Reference spectra represented proteins, lipids, nucleic acids, carbohydrates, amino acids and other miscellaneous molecules. A non-negative least-squares algorithm was used for fitting. Individual spectra per histopathological annotation were then fitted with this selected library in order to determine the molecular composition per tissue structure. The spectral contribution per chemical class was calculated. The results show that all characteristic tissue-type spectra could be fitted with a low residual of <4.82%. The content of carbohydrates, proteins and amino acids was the strongest discriminator between OCSCC and healthy tissue. The combination of carbohydrates, proteins and amino acids was used for a classification model of 'tumor' versus 'healthy tissue'. Validation of this model on an independent dataset showed a specificity of 93% at a sensitivity of 100%.

Effects of transforming growth factor-ß subtypes on in vitro cartilage production and mineralization of human bone marrow stromal-derived mesenchymal stem cells.

Human bone marrow stromal-derived mesenchymal stem cells (hBMSCs) will differentiate into chondrocytes in response to defined chondrogenic medium containing transforming growth factor-ß (TGFß). Results in the literature suggest that the three mammalian subtypes of TGFß (TGFß1, TGFß2 and TGFß3) provoke certain subtype-specific activities. Therefore, the aim of our study was to investigate whether the TGFß subtypes affect chondrogenic differentiation of in vitro cultured hBMSCs differently. HBMSC pellets were cultured for 5 weeks in chondrogenic media containing either 2.5, 10 or 25 ng/ml of TGFß1, TGFß2 or TGFß3. All TGFß subtypes showed a comparable dose-response curve, with significantly less cartilage when 2.5 ng/ml was used and no differences between 10 and 25 ng/ml. Four donors with variable chondrogenic capacity were used to evaluate the effect of 10 ng/ml of either TGFß subtype on cartilage formation. No significant TGFß subtype-dependent differences were observed in the total amount of collagen or glycosaminoglycans. Cells from a donor with low chondrogenic capacity performed equally badly with all TGFß subtypes, while a good donor overall performed well. After addition of ß-glycerophosphate during the last 2 weeks of culture, the expression of hypertrophy markers was analysed and mineralization was demonstrated by alkaline phosphatase activity and alizarin red staining. No significant TGFß subtype-dependent differences were observed in expression collagen type X or VEGF secretion. Nevertheless, pellets cultured with TGFß1 had significantly less mineralization than pellets cultured with TGFß3. In conclusion, this study suggests that TGFß subtypes do affect terminal differentiation of in vitro cultured hBMSCs differently.