The Role of Biomaterials in Upper Digestive Tract Transoral Reconstruction

This study aims to establish whether the use of biomaterials, particularly polydimethylsiloxane (PDMS), for surgical reconstruction of the esophagus with templates, Montgomery salivary tube, after radical oncology surgery for malignant neoplasia is an optimal choice for patients' safety and for optimal function preservation and organ rehabilitation. Structural analysis by Raman spectrometry and biomechanical properties with dynamic mechanical analysis are performed for fatigue strength and toughness, essential factors in durability of a prosthesis in the reconstruction practice of the esophagus. Nanocomposites with silicone elastomers and nanoparticles used in implantable devices and in reconstruction surgery present risks of infection and fatigue strength when required to perform a mechanical effort for long periods of time. This report takes into account the effect of silver (Ag) nanoparticles on the fatigue strength using polydimethylsiloxane (PDMS) matrix, representative for silicon elastomers used in implantable devices. PDMS with 5% (wt) Ag nanoparticles of 100-150 nm during mechanical fatigue testing at shear strength loses elasticity properties after 400 loading-unloading cycles and up to 15% shear strain. The fatigue strength, toughness, maximum shear strength, as well as clinical properties are key issues in designing Montgomery salivary tube and derivates with appropriate biomechanical behavior for each patient. Prosthesis design needs to indulge both clinical outcomes as well as design methods and research in the field of biomaterials.

GASTRO-ESOPHAGEAL REFLUX DISEASE AND ITS IMPACT ON TRACHEO-ESOPHAGEAL SPEAKING VALVE REHABILITATION AFTER TOTAL LARYNGECTOMY

Gastro-esophageal reflux disease (GERD) is a pathological entity in which the mixture of gastric contents (with low pH because of the high content of HCl acid) and biliary juice (rich in proteolytic enzymes like pepsin and trypsin) causes lesions on the mucosa lining the esophagus. A higher prevalence of GERD was discovered in patients who had a total laryngectomy. Concerning laryngectomies with tracheo-esophageal speaking valves, it has been demonstrated that GERD is an independent risk factor for failure of this method of speech rehabilitation. The authors performed an analysis of English language articles found following a search of the major medical scientific databases (NCBI®, EMBASE®, Cochrane®) containing the following keyword string: vocal prosthesis, total laryngectomy, GERD, acid reflux, tracheo-esophageal fistula, failure. Studies showed that exposure to the protelolytic enzymes from the reflux juice increases the diameter of the tracheo-esophageal fistula and permits local granulation tissue to form. Progressively, the increasing fistula diameter leads to complications ranging from microaspiration of liquids and saliva to speaking valve expulsion or ingestion and temporary incapacity of oral feeding. Medical therapy in the postoperative period as well as long-term (6 months or more) correction of GERD (PPI therapy, H2 blockers, prokinetics) is also demonstrated to reduce the complication rate in this category of patients. GERD has a high prevalence in the total laryngectomy population of patients and it has multiple etiologic factors. In patients with tracheoesophageal vocal prostheses, GERD causes an increase in the fistula diameter – with important consequences that affect the patient's quality of life - his ability to phonate and his ability to swallow. These complications come with added costs because of the need to more frequently change the vocal prostheses with ones increasing in diameter, as well as multiple hospitalizations (even surgery to recalibrate or close the tracheo-esophageal fistula). Recognizing and treating this condition therefore decreases the risk of complications following vocal prosthesis speech rehabilitation.

The laryngocele; case presentation

Laryngocele is a rare pathology, but because of their clinical evolution and the symptoms they generate, they should always be considered as a differential diagnosis when investigating neck masses. A laryngocele is basically a herniation of the mucosa of the laryngeal ventricle (Morgagni's ventricle) arising usually from the saccular region. This herniation may remain confined to the larynx - in which case the laryngocele is internal- or expand through the thyro-hyoid membrane into the structures of the neck - thus being called an external laryngocele. Usually the laryngocele has both an internal and external component thus being a mixed laryngocele. Diagnosis of laryngoceles still relies heavily on clinical signs such as tympanism, easily depressible neck mass, indirect laryngoscopy, but is now simplified by imagistic investigations (ultrasound, CT and MRI). However, the treatment of this condition is exclusively surgical and consists of total excision of the laryngocele, as well as proper identification of the point of origin from the saccule and also the final suture of the breach in order to prevent recurrence. Investigation of possible causes of obstruction of the laryngeal ventricle should always be performed (because of the possibility of an underlying malignancy) as well as a follow-up protocol of the patient, given the risk of relapse. We present a recently diagnosed case of a 32 year old man with mixed laryngocele, which we have operated in our clinic.