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Background: Little is known about the growth rate of cholesteatoma in patients. Objective: Investigate the growth of residual cholesteatoma in subtotal petrosectomy based on volume measured in MRI scans. Materials and methods: Retrospective case series in a Tertiary Medical Centre. Thirteen residual cholesteatomas were identified in 10 patients after subtotal petrosectomy for which a wait-and-scan policy was adopted. Volume of the residual cholesteatoma was calculated by manual segmentation as well as the ‘box method’. Results: Mean growth rate was 27.9 mm3/month (SD 22.8), with a large individual variation ranging from 2.2 to 69.8 mm3/month. No complications were reported in 10 patients with a wait-and-scan policy for residual cholesteatoma in subtotal petrosectomy. The box method overestimates growth rate compared to the reference method manual segmentation and a linear increase of this systematic error was seen with increasing size of the cholesteatoma. Conclusions: Residual cholesteatoma growth rate shows a large individual variation. A wait-and-scan policy could be considered in case of a (small) residual in subtotal petrosectomy with ample room to grow before destroying any remaining structures. Furthermore, the clinically more applicable and less time-consuming box method can be used to accurately measure volumes of small cholesteatomasup to a volume of 500 mm 3 .

Foreign body ingestion occurs frequently in children and may lead to severe complications and mortality. In this article, three cases are presented. A 2-year-old boy swallowed a plastic toy helmet. He had no symptoms and physical examination was normal, and the toy was found in the stool within three days. Similarly, a 6-year-old girl swallowed two magnets and was asymptomatic. Physical examination was normal and a radiograph showed a foreign body which had passed the stomach. Due to the location, endoscopic removal by gastroduodenoscopy was not possible and surgical removal unnecessary. The magnets were secreted in the stool within two days. A 10-year-old boy with VACTERL association and psychiatric history, swallowed a button battery. After a delay in presentation, a radiograph showed a button battery mid-esophageal, which was endoscopically removed. He also needed dilatation due to esophageal stenosis. The above cases are all illustrative of the topic covered in the guideline 'Ingestion of foreign bodies in children aged 0-18 years', which was developed on behalf of the Dutch Pediatric Association and published in March 2019.

OBJECTIVES/HYPOTHESIS The objective of this study was to evaluate surgical outcome and residual and recurrence rates of canal wall up (CWU) surgery with obliteration of the mastoid and epitympanum. STUDY DESIGN Retrospective cohort study in a tertiary referral center. METHODS Patients with (sequelae of) acquired cholesteatoma treated with primary or revision CWU surgery with obliteration of the epitympanum and mastoid were identified retrospectively from 2010 to 2014. Obliteration was performed with cartilage chips or a periosteal midtemporal flap in combination with bone pâte and/or hydroxyapatite. Patients were followed up with micro-otoscopy and magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI). RESULTS Ninety-nine ears in 96 patients were managed with obliteration of the epitympanum and mastoid following CWU surgery. Mean postoperative follow-up was 39.6 (standard deviation [SD] = 16.3). Mean follow-up until the last MRI-DWI was 29.7 months (SD = 16.0). In total, 74 ears in 72 adult patients (mean age = 46.8 years) were operated and 25 ears in 24 pediatric patients (mean age = 12.8 years). The overall recurrence rate was 7.1%, and the residual rate was 7.1%. In comparison, before the introduction of obliteration, the residual rate in our clinic was 24.4% and the recurrence rate 39.7%. After CWU surgery with obliteration, recurrence in pediatric patients (16.0%) was more frequent than in adults (4.1%). Although this difference was not statistically significant, a trend was observed (P = .066). CONCLUSIONS Obliteration of the epitympanum and mastoid is a reliable and safe technique following CWU surgery for cholesteatoma, resulting in low residual and recurrence rates. LEVEL OF EVIDENCE 4 Laryngoscope, 129:981-985, 2019.

Articular cartilage is easily damaged, yet difficult to repair. Cartilage tissue engineering seems a promising therapeutic solution to restore articular cartilage structure and function, with mesenchymal stem cells (MSCs) receiving increasing attention for their promise to promote cartilage repair. It is known from embryology that members of the fibroblast growth factor (FGF), transforming growth factor-β (TGFβ) and wingless-type (Wnt) protein families are involved in controlling different differentiation stages during chondrogenesis. Individually, these pathways have been extensively studied but so far attempts to recapitulate embryonic development in in vitro MSC chondrogenesis have failed to produce stable and functioning articular cartilage; instead, transient hypertrophic cartilage is obtained. We believe a better understanding of the simultaneous integration of these factors will improve how we relate embryonic chondrogenesis to in vitro MSC chondrogenesis. This narrative review attempts to define current knowledge on the crosstalk between the FGF, TGFβ and Wnt signalling pathways during different stages of mesenchymal chondrogenesis. Connecting embryogenesis and in vitro differentiation of human MSCs might provide insights into how to improve and progress cartilage tissue engineering for the future. Copyright © 2013 John Wiley & Sons, Ltd.

Human bone marrow stromal-derived mesenchymal stem cells (hBMSCs) will differentiate into chondrocytes in response to defined chondrogenic medium containing transforming growth factor-beta (TGF beta). Results in the literature suggest that the three mammalian subtypes of TGF beta (TGF beta 1, TGF beta 2 and TGF beta 3) provoke certain subtype-specific activities. Therefore, the aim of our study was to investigate whether the TGF beta 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 TGF beta 1, TGF beta 2 or TGF beta 3. All TGF beta 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 TGF beta subtype on cartilage formation. No significant TGF beta 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 TGF beta subtypes, while a good donor overall performed well. After addition of beta-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 TGF beta subtype-dependent differences were observed in expression collagen type X or VEGF secretion. Nevertheless, pellets cultured with TGF beta 1 had significantly less mineralization than pellets cultured with TGF beta 3. In conclusion, this study suggests that TGF beta subtypes do affect terminal differentiation of in vitro cultured hBMSCs differently. Copyright (C) 2011 John Wiley & Sons, Ltd.

Item does not contain fulltext The aim of this study was to investigate the roles of Smad2/3 and Smad1/5/8 phosphorylation in transforming growth factor-beta-induced chondrogenic differentiation of bone-marrow-derived mesenchymal stem cells (BMSCs) to assess whether specific targeting of different Smad signaling pathways offers possibilities to prevent terminal differentiation and mineralization of chondrogenically differentiated BMSCs. Terminally differentiated chondrocytes produced in vitro by chondrogenic differentiation of BMSCs or studied ex vivo during murine embryonic limb formation stained positive for both Smad2/3P and Smad1/5/8P. Hyaline-like cartilage produced in vitro by articular chondrocytes or studied in ex vivo articular cartilage samples that lacked expression for matrix metalloproteinase 13 and collagen X only expressed Smad2/3P. When either Smad2/3 or Smad1/5/8 phosphorylation was blocked in BMSC culture by addition of SB-505124 or dorsomorphin throughout culture, no collagen II expression was observed, indicating that both pathways are involved in early chondrogenesis. Distinct functions for these pathways were demonstrated when Smad signaling was blocked after the onset of chondrogenesis. Blocking Smad2/3P after the onset of chondrogenesis resulted in a halt in collagen II production. On the other hand, blocking Smad1/5/8P during this time period resulted in decreased expression of matrix metalloproteinase 13, collagen X, and alkaline phosphatase while allowing collagen II production. Moreover, blocking Smad1/5/8P prevented mineralization. This indicates that while Smad2/3P is important for continuation of collagen II deposition, Smad1/5/8 phosphorylation is associated with terminal differentiation and mineralization.

The aim of this study was to evaluate the potential of culture-expanded human auricular and nasoseptal chondrocytes as cell source for regeneration of stable cartilage and to analyze the differences in gene expression profile of expanded chondrocytes from these specific locations. Auricular chondrocytes in monolayer proliferated less and more slowly (two passages took 26.7 ± 2.1 days and were reached in 4.37 ± 0.30 population doublings) than nasoseptal chondrocytes (19.3 ± 2.5 days; 5.45 ± 0.20 population doublings). However, auricular chondrocytes produced larger pellets with more cartilage-like matrix than nasoseptal chondrocytes (2.2 ± 0.71 vs. 1.7 ± 0.13 mm in diameter after 35 days of culture). Although the matrix formed by auricular and nasoseptal chondrocytes contained collagen X, it did not mineralize in an in vitro model or after in vivo subcutaneous implantation. A DNA microarray study on expanded auricular and nasoseptal chondrocytes from the same donors revealed 1,090 differentially expressed genes. No difference was observed in the expression of known markers of chondrogenic capacity (e.g., collagen II, FGFR3, BMP2, and ALK1). The most striking differences were that the auricular chondrocytes had a higher expression of anabolic growth factors BMP5 and IGF1, while matrix-degrading enzymes MMP13 and ADAMTS5 were higher expressed in nasoseptal chondrocytes. This might offer a possible explanation for the observed higher matrix production by auricular chondrocytes. Moreover, chondrocytes isolated from auricular or nasoseptal cartilage had specific gene expression profiles even after expansion. These differently expressed genes were not restricted to known characterization of donor site subtype (e.g., elastic), but were also related to developmental processes.

Adult mesenchymal stem cells (MSCs) are considered promising candidate cells for therapeutic cartilage and bone regeneration. Because tissue regeneration and embryonic development may involve similar pathways, understanding common pathways may lead to advances in regenerative medicine. In embryonic limb development, fibroblast growth factor receptors (FGFRs) play a role in chondrogenic differentiation. The aim of this study was to investigate and compare FGFR expression in in vivo embryonic limb development and in vitro chondrogenesis of MSCs. Our study showed that in in vitro chondrogenesis of MSCs three sequential stages can be found, as in embryonic limb development. A mesenchymal condensation (indicated by N-cadherin) is followed by chondrogenic differentiation (indicated by collagen II), and hypertrophy (indicated by collagen X). FGFR1-3 are expressed in a stage-dependent pattern during in vitro differentiation and in vivo embryonic limb development. In both models FGFR2 is clearly expressed by cells in the condensation phase. No FGFR expression was observed in differentiating and mature hyaline chondrocytes, whereas hypertrophic chondrocytes stained strongly for all FGFRs. To evaluate whether stage-specific modulation of chondrogenic differentiation in MSCs is possible with different subtypes of FGF, FGF2 and FGF9 were added to the chondrogenic medium during different stages in the culture process (early or late). FGF2 and FGF9 differentially affected the amount of cartilage formed by MSCs depending on the stage in which they were added. These results will help us understand the role of FGF signaling in chondrogenesis and find new tools to monitor and control chondrogenic differentiation.

Background and Purpose— Cerebrospinal fluid drainage is often indicated in patients with acute hydrocephalus after aneurysmal subarachnoid hemorrhage but is believed to increase the risk of rebleeding. We studied the risk of rebleeding in patients with subarachnoid hemorrhage during treatment for acute hydrocephalus. Methods— We included patients with hydrocephalus treated with external ventricular drainage or lumbar punctures within 4 days after the hemorrhage and before aneurysm occlusion. Each treated patient was matched with a control patient with untreated hydrocephalus and a control patient without ventricular enlargement. Patients and controls were matched for interval since subarachnoid hemorrhage, duration of exposure, use of tranexamic acid, clinical condition on admission, and age. We used Cox regression to calculate hazard ratios and we adjusted for rebleeding that had occurred before starting the cerebrospinal fluid drainage. Results— In the group treated with external ventricular drainage, rebleeding occurred in seven of 34 patients (21%) with treatment, in seven of 34 controls (21%) with untreated hydrocephalus, and in six of 34 controls (18%) without hydrocephalus. In the group treated with one or more lumbar punctures, rebleeding occurred in one of 21 patients (5%) with treatment, in three of 21 controls (14%) with untreated hydrocephalus, and in none of the 21 controls without hydrocephalus. The hazard ratios for rebleeding were 1.0 (95% CI: 0.4 to 2.7) for external ventricular drainage treatment and 0.7 (95% CI: 0.1 to 6.4) for lumbar puncture treatment. Conclusion— This study does not confirm an importantly increased risk of rebleeding during external ventricular drainage or lumbar punctures for acute hydrocephalus after aneurysmal subarachnoid hemorrhage.

Articular cartilage is easily damaged, yet difficult to repair. Cartilage tissue engineering seems a promising therapeutic solution to restore articular cartilage structure and function, with mesenchymal stem cells (MSCs) receiving increasing attention for their promise to promote cartilage repair. It is known from embryology that members of the fibroblast growth factor (FGF), transforming growth factor-β (TGFβ) and wingless-type (Wnt) protein families are involved in controlling different differentiation stages during chondrogenesis. Individually, these pathways have been extensively studied but so far attempts to recapitulate embryonic development in in vitro MSC chondrogenesis have failed to produce stable and functioning articular cartilage; instead, transient hypertrophic cartilage is obtained. We believe a better understanding of the simultaneous integration of these factors will improve how we relate embryonic chondrogenesis to in vitro MSC chondrogenesis. This narrative review attempts to define current knowledge on the crosstalk between the FGF, TGFβ and Wnt signalling pathways during different stages of mesenchymal chondrogenesis. Connecting embryogenesis and in vitro differentiation of human MSCs might provide insights into how to improve and progress cartilage tissue engineering for the future.

Chondrogenically differentiating bone marrow-derived mesenchymal stem cells (BMSCs) display signs of chondrocyte hypertrophy, such as production of collagen type X, MMP13 and alkaline phosphatase (ALPL). For cartilage reconstructions this is undesirable, as terminally differentiated cartilage produced by BMSCs mineralizes when implanted in vivo. Terminal differentiation is not restricted to BMSCs but is also encountered in chondrogenic differentiation of adipose-derived mesenchymal stem cells (MSCs) as well as embryonic stem cells, which by definition should be able to generate all types of tissues, including stable cartilage. Therefore, we propose that the currently used culture conditions may drive the cells towards terminal differentiation. In this manuscript we aim to review the literature, supplemented by our own data to answer the question, is it possible to generate stable hyaline cartilage from adult MSCs? We demonstrate that recently published methods for inhibiting terminal differentiation (through PTHrP, MMP13 or blocking phosphorylation of Smad1/5/8) result in cartilage formation with reduction of hypertrophic markers, although this does not reach the low level of stable chondrocytes. A set of hypertrophy markers should be included in future studies to characterize the phenotype more precisely. Finally, we used what is currently known in developmental biology about the differential development of hyaline and terminally differentiated cartilage to provide thought and insights to change current culture models for creating hyaline cartilage. Inhibiting terminal differentiation may not result in stable hyaline cartilage if the right balance of signals has not been created from the start of culture onwards.

The use of bioengineered cell constructs for the treatment of bone defects has received much attention of late. Often, bone marrow stromal cells (BMSCs) are used that are in vitro-stimulated toward the osteogenic lineage, aiming at intramembranous bone formation. The success of this approach has been disappointing. A major concern with these constructs is core degradation and necrosis caused by lack of vascularization. We hypothesized that stimulation of cells toward the endochondral ossification process would be more successful. In this study, we tested how in vitro priming of human BMSCs (hBMSCs) along osteogenic and chondrogenic lineages influences survival and osteogenesis in vivo. Scaffolds that were pre-cultured on chondrogenic culture medium showed collagen type II and collagen type X production. Moreover, vessel ingrowth was observed. Priming along the osteogenic lineage led to a mineralized matrix of poor quality, with few surviving cells and no vascularization. We further characterized this process in vitro using pellet cultures. In vitro, pellets cultured in chondrogenic medium showed progressive production of collagen type II and collagen type X. In the culture medium of these chondrogenic cultured pellets, vascular endothelial growth factor (VEGF) release was observed at days 14, 21, and 35. When pellets were switched to culture medium containing beta-glycerophosphate, independent of the presence or absence of transforming growth factor beta (TGF-beta), mineralization was observed with a concomitant reduction in VEGF and matrix metalloproteinase (MMP) release. By showing that VEGF and MMPs are produced in chondrogenically differentiated hBMSCs in vitro, we demonstrated that these cells produce factors that are known to be important for the induction of vascularization of the matrix. Inducing mineralization in this endochondral process does, however, severely diminish these capacities. Taken together, these data suggest that optimizing chondrogenic priming of hBMSCs may further improve vessel invasion in bioengineered constructs, thus leading to an alternative and superior approach to bone repair.

Although in the past cochlear implantation was considered contraindicated in patients with acute (AOM) or chronic suppurative otitis media (CSOM) with or without middle ear cholesteatoma, recent developments now make it possible to perform cochlear implantation in these patients. Various procedures are available to make the ears of patients with either acute or CSOM suitable for cochlear implantation and to minimize the risk of recurrence of the disease, device extrusion, or intracranial complications. This review discusses these different approaches for optimizing implant survival and preventing complications related to otitis media. We performed a comprehensive literature search of the MEDLINE database. Cochlear implantation can be safely performed in patients with otitis media. However, the infection should be adequately controlled well before implantation, and all measures should be taken to prevent recurrent disease. Therefore, the procedure used should be tailored to individual clinical findings. This article provides a guideline to optimize the course of action in patients suffering from AOM, CSOM or their sequelae in preparation for cochlear implantation.