Comparison of the application of artificial ossicles and autologous ossicles in the reconstruction of a damaged ossicular chain

[Chronic mesotympanic Otitis media - Part 2: Surgical Therapy]

Chronic mesotympanal otitis media (CMOM) is a well-developed clinical presentation that is established in diagnostics and therapy. On closer inspection, however, this principle cannot be confirmed in all its facets. Already the physiology and pathophysiology of the middle ear mucosa leave questions unanswered, starting with the distribution of the ciliated epithelium in the middle ear and mastoid to the function of gas exchange.In addition, there are new diagnostic and therapeutic approaches. In the future, optical coherence tomography could help to determine the status of the middle ear mucosa. In addition, there are new findings on the effectiveness of local and systemic antibiotics as well as antiseptics in chronic otorrhea. Other new developments include minimally invasive surgical procedures using endoscopic techniques. All this gives reason to provide an update on the topic of chronic mesotympanal otitis media, which should contribute in preparation for the specialist examination or refreshing.Basics of physiology and pathophysiology as well as new diagnostic approaches and medical treatment were covered in Part 1 of this paper. In Part 2, in addition to established methods, new developments in surgical therapy with minimally invasive surgical procedures are described in more detail.

FDA MAUDE database analysis of titanium middle ear prosthesis

Purpose

Partial ossicular replacement (PORP) and total ossicular replacement prostheses (TORP) are used to restore ossicular chain function. Despite favorable auditory outcomes, these interventions have associated risks and complications. This study examines the FDA MAUDE database for ossicular chain prosthesis adverse events to highlight complications, interventions, and root cause analysis (RCA) findings.

Materials and methods

The MAUDE database was searched for Medical Device Reports (MDRs) relating to PORPs and TORPs from 2010 to 2020. MDR event descriptions were reviewed, and adverse events were identified as a device issue, patient issue, and/or packaging issue that occurred intraoperatively or postoperatively.

Results

Our search identified 70 MDRs which included 110 reported adverse events. Events consisted of 63 device issues, often due to device breaks and displacements, 39 patient issues, including common complaints of hearing loss and erosion, and 8 packaging issues. When comparing PORPs and TORPs, TORPs had more reported device issues whereas PORPs had more packaging issues. Intraoperative device issues were commonly resolved by completing the procedure with a backup device and most postoperative device issues required additional surgery. For devices returned to the manufacturer, RCA determined that most breaks were caused by modification and/or mishandling or that the product met specifications with an undetermined cause for the break.

Conclusion

Device issues were the most common adverse events and frequently required subsequent intervention. Displacement occurred more often with TORPs and was associated with changes in hearing or erosion. The findings of this study are purely descriptive and may not have direct clinical relevance.

The suitability of scanning electron microscopy in the evaluation of bone structure surfaces and selection of alloplastic materials for facial skeletal reconstruction

INTRODUCTION

Functional and aesthetic problems can arise even from small losses created in the facial skeleton. Injuries and oncological surgeries are the most frequent causes of these losses within the facial skeleton. Advances in surgical interventions have allowed for ever-increasing degrees of resections, increasing oncological radicality as well as treatment effectiveness, providing the patient with the chance for a longer life. However, this subsequently requires the use of even more advanced reconstruction techniques in order to restore quality of life and comfort to the patient, as well as enable their return to professional and social activities. The necessity of reconstructive surgery applies not only to patients with cancer, but also to patients with impaired or failing sensory and organ function as a result of inflammatory conditions, injuries, or non-oncological surgeries. There are many available reconstruction procedures, which depend on the location of the loss, the type of tissue lost, the degree of loss and patient-dependent factors. Materials used in reconstruction surgeries may include the patients' tissues when available, and artificial reconstruction materials otherwise.

MATERIAL AND METHODS

The analysis involved fragments of bone tissue removed during surgery. Due to the nature of the medical procedure and the inability to replant the tissue, it was regarded as medical waste. The preparations used were observed under an optical microscope and an electron scanning microscope, and a chemical analysis was performed. The chemical composition of samples was analysed using a low vacuum detector (LVD) at an accelerating voltage of 15 kV and 10 kV and at a spot size of 4 and 3.5. The observations were performed in a secondary electron (SE) detection system.

RESULTS

Observation of parameters under an optical microscope and of images obtained using an electron scanning microscope showed the presence of typical, compact bone tissue with varied surface shapes in each case (various degrees of unevenness and porosity). Chemical composition analysis confirmed the presence of compounds from the CaO-P2O5-H20 system. The Ca/P (calcium/phosphorus) ratio obtained from the chemical analysis varied from 1.33 to 2.1, and indicated a varied morphology of calcium phosphates forming the bone structures of the facial skeleton.

CONCLUSIONS

1. Calcium phosphates are characterised by excellent biocompatibility because of their chemical affinity to bone, and are ideal for the reconstruction of bone losses within the facial skeleton. 2. Biodegradable polymers have the highest functional potential among several groups of biomaterials used in tissue engineering because of their ability to be tailored individually, in addition to their high biocompatibility.