Partial laryngectomy for the management of laryngeal masses in six cats

Objectives Partial laryngectomy is an organ-sparing surgical procedure for the removal of laryngeal masses which has not been described in cats. The aim of this study was to report on the surgical procedure and the short- and long-term clinical outcomes of cats that underwent partial laryngectomy. Methods Medical records were retrospectively collected over a 4-year period in two institutions. The following data were retrieved: signalment, history, clinical signs, diagnostic test results, surgical procedure, postoperative management, complications and outcome. Results Six cats underwent partial laryngectomy. The most common clinical signs in cats with laryngeal masses were stridor (n = 4) and dyspnoea (n = 4). In all cats, a full-thickness portion of one or several laryngeal cartilages was resected, including thyroid cartilage alone (n = 2), thyroid cartilage and arytenoid (n = 2), and arytenoid cartilage and epiglottis (n = 2). The resected laryngeal masses were reported to be lymphoma (n = 3), carcinoma (n = 1), laryngeal cyst (n = 1) and inflammatory laryngeal disease (n = 1). All cats survived the surgical intervention of partial laryngectomy. Four cats showed varying degrees of respiratory distress in the short-term postoperative period. A temporary tracheostomy tube was placed in two cats. No other postoperative complications were noted in the short- or long-term. Four cats were still alive at the time of writing. These cats survived at least 252 days. Conclusions and relevance In a small number of cases, our results show that successful long-term outcomes after partial laryngectomy are achievable, with longer survival times than previously reported. Therefore, partial laryngectomy should be considered as a viable treatment option in cats with laryngeal masses.

Anatomic and histologic analysis of paca larynx (Cuniculus paca, Linnaeus 1766)

ABSTRACT Paca (Cuniculus paca) has encouraged research as an experimental model both in the human medicine and veterinary, as well as the economic exploitation of its meat cuts, which favored its zootechnical use. There are no anatomical, microscopic descriptions and measurements of the larynx in this rodent. Eight pacas were dissected from the wild animal’s sector of the Faculty of Agricultural and Veterinary Sciences of the University of the State of São Paulo. The larynx was observed located in the ventral region of the neck, ventral to the esophagus, connecting the pharynx to the trachea, with cylindrical and irregular shape. Laryngeal cartilages (epiglottic, thyroid, cricoid and arytenoid) are interconnected and have different shapes. Thyroid showed greater length and width, compared to the others. Laryngeal cartilages were submitted to histological processing and stained with hematoxylin-eosin and Masson's trichrome. The epiglottic cartilage was stained with toluidine blue. Laryngeal cartilages thyroid, cricoid and the lower portion of the arytenoids are of hyaline origin and, in contrast, the epiglottis and the upper portion of the arytenoids are elastic. This latter cartilage demonstrated taste buds. The results will be able to auxiliate in veterinary care and as well as the conservation programs for this rodent.

Variants of surgical treatment of chronic post-intubation laryngeal stenosis in children

Objective. To evaluate the effectiveness of a surgical tactics used for the treatment of children with chronic post-intubation laryngeal stenosis depending on the condition of their laryngeal cartilages. Patients and methods. We treated 47 children with chronic post-intubation laryngeal stenosis. Preoperative examination included endoscopy and computed tomography (CT) of the larynx and trachea. We evaluated the condition of their laryngeal cartilages in order to choose an optimal surgical tactics. Children with intact laryngeal cartilages (n = 20) have undergone endolaryngeal microsurgery using a CO2 laser. This method caused minimal injury due to submucosal excision of scar tissue, which enabled wound coverage with mucous microflaps to prevent recurrent stenosis. Surgery for extensive stenosis in the middle portion of the larynx was associated with a risk of recurrent scarring. In our study, we prevented it by using endografts during 21 days. However, patients with lesions in the subglottic larynx still had a high risk of recurrent stenosis (5 out of 12 patients) even if there was no evidence of damage to the laryngeal cartilages. Results. Twenty-seven patients with laryngeal post-intubation stenosis with lesions to the laryngeal cartilages detected before surgery have undergone extralaryngeal laryngotracheoplasty. Eighteen children have undergone laryngofissure with subsequent stenting between 6 and 18 months with a T-shaped silicone stent. Nine patients have undergone single-stage laryngotracheoplasty with autologous grafts. Conclusion. The methods used in this study have demonstrated high effectiveness, while the use of grafts reduced the number of stages of surgery and its duration. Key words: laryngotracheoplasty in children, laryngeal microsurgery, complications of tracheal intubation in children, chronic laryngeal stenosis, cartilage autologous grafts, CO2 laser

Postnatal Development of the Mouse Larynx: Negative Allometry, Age-Dependent Shape Changes, Morphological Integration, and a Size-Dependent Spectral Feature

Purpose The larynx plays a role in swallowing, respiration, and voice production. All three functions change during ontogeny. We investigated ontogenetic shape changes using a mouse model to inform our understanding of how laryngeal form and function are integrated. We understand the characterization of developmental changes to larynx anatomy as a critical step toward using rodent models to study human vocal communication disorders. Method Contrast-enhanced micro-computed tomography image stacks were used to generate three-dimensional reconstructions of the CD-1 mouse ( Mus musculus ) laryngeal cartilaginous framework. Then, we quantified size and shape in four age groups: pups, weanlings, young, and old adults using a combination of landmark and linear morphometrics. We analyzed postnatal patterns of growth and shape in the laryngeal skeleton, as well as morphological integration among four laryngeal cartilages using geometric morphometric methods. Acoustic analysis of vocal patterns was employed to investigate morphological and functional integration. Results Four cartilages scaled with negative allometry on body mass. Additionally, thyroid, arytenoid, and epiglottic cartilages, but not the cricoid cartilage, showed shape change associated with developmental age. A test for modularity between the four cartilages suggests greater independence of thyroid cartilage shape, hinting at the importance of embryological origin during postnatal development. Finally, mean fundamental frequency, but not fundamental frequency range, varied predictably with size. Conclusion In a mouse model, the four main laryngeal cartilages do not develop uniformly throughout the first 12 months of life. High-dimensional shape analysis effectively quantified variation in shape across development and in relation to size, as well as clarifying patterns of covariation in shape among cartilages and possibly the ventral pouch. Supplemental Material https://doi.org/10.23641/asha.12735917

Contrast-enhanced ultrasound in the diagnosis of head and neck squamous cell carcinoma

The study objectiveis to evaluate the capacity of contrast-enhanced ultrasound in the diagnosis of head and neck squamous cell carcinoma.Materials and methods. We examined 34 patients with head and neck tumors (or suspected of having a tumor) using contrast-enhanced ultrasound imaging with sulfur hexafluoride.Results. Contrast enhancement of primary and recurrent tumors (developed within 3 months since the end of treatment) was characterized by rapid wash-in (including peak enhancement) and wash-out of contrast agent. However, recurrent tumors (developed within 3 months after treatment) demonstrated slightly slower wash-in than primary tumors. In patients with suspected relapse, which was not confirmed by histological examination, contrast agent accumulated only in the surrounding tissues and did not penetrate into the fibrous infiltrate; there were no wash-in and wash-out phases (although this did not exclude the presence of small tumors in the infiltrate). By contrast, tumors demonstrated rapid achievement of peak enhancement and fast wash-out. Laryngeal and laryngopharyngeal tumors accumulate and release contrast agent like any other oropharyngeal squamous cell carcinomas. Laryngeal cartilages have high echogenicity and don’t accumulate contrast agent. Tumor-altered vocal cords accumulate contrast agent, which significantly improves the visualization. Intact vocal cords appear as hyperechogenic symmetric structures on B-scans. Contrast-enhanced ultrasound imaging allows better visualization of the vocal cords. Contrast-enhancement can significantly improve the diagnostic value of ultrasound examination of the larynx, especially when B-scanning is hindered by some anatomical features (such as large Adam’s apple) or ossification of laryngeal cartilages.Conclusion. Contrast-enhanced ultrasound imaging of the head and neck is a highly promising diagnostic tool, although it requires further evaluation. Improved visualization with contrast-enhancement increases the diagnostic value of the method for the differentiation between various tumors and fibrotic changes and detection of tumor spread to the laryngeal cartilages, which is important for surgical treatment and planning anticancer therapy.

Identity and novelty in the avian syrinx

In its most basic conception, a novelty is simply something new. However, when many previously proposed evolutionary novelties have been illuminated by genetic, developmental, and fossil data, they have refined and narrowed our concept of biological “newness.” For example, they show that these novelties can occur at one or multiple levels of biological organization. Here, we review the identity of structures in the avian vocal organ, the syrinx, and bring together developmental data on airway patterning, structural data from across tetrapods, and mathematical modeling to assess what is novel. In contrast with laryngeal cartilages that support vocal folds in other vertebrates, we find no evidence that individual cartilage rings anchoring vocal folds in the syrinx have homology with any specific elements in outgroups. Further, unlike all other vertebrate vocal organs, the syrinx is not derived from a known valve precursor, and its origin involves a transition from an evolutionary “spandrel” in the respiratory tract, the site where the trachea meets the bronchi, to a target for novel selective regimes. We find that the syrinx falls into an unusual category of novel structures: those having significant functional overlap with the structures they replace. The syrinx, along with other evolutionary novelties in sensory and signaling modalities, may more commonly involve structural changes that contribute to or modify an existing function rather than those that enable new functions.

Different Patterns of Cartilage Mineralization Analyzed by Comparison of Human, Porcine, and Bovine Laryngeal Cartilages

Laryngeal cartilages undergo a slow ossification process during aging, making them an excellent model for studying cartilage mineralization and ossification processes. Pig laryngeal cartilages are similar to their human counterparts in shape and size, also undergo mineralization, facilitating the study of cartilage mineralization. We investigated the processes of cartilage mineralization and ossification and compared these with the known processes in growth plates. Thyroid cartilages from glutaraldehyde-perfused male minipigs and from domestic pigs were used for X-ray, light microscopic, and transmission electron microscopic analyses. We applied different fixation and postfixation solutions to preserve cell shape, proteoglycans, and membranes. In contrast to the ossifying human thyroid cartilage, predominantly cartilage mineralization was observed in minipig and domestic pig thyroid cartilages. The same subset of chondrocytes responsible for growth plate mineralization is also present in thyroid cartilage mineralization. Besides mineralization mediated by matrix vesicles, a second pattern of cartilage mineralization was observed in thyroid cartilage only. Here, the formation and growth of crystals were closely related to collagen fibrils, which served as guide rails for the expansion of mineralization. It is hypothesized that the second pattern of cartilage mineralization may be similar to a maturation of mineralized cartilage after initial matrix vesicles–mediated cartilage mineralization.