A CFD approach to understand nasoseptal perforations.

INTRODUCTION: Nasoseptal perforations (NSP) are becoming common in the modern world, and can cause a wide variety of symptoms, including a sensation of nasal obstruction, epistaxis, crusting, dryness, headache, nasal pain and a whistling sound. There is an extensive range of surgical treatment techniques, but reported results were rarely statistically significant. The lack of consistent surgical results may be related to the lack of knowledge about the pathophysiology of NSP and how they affect the nasal flow. Computational fluid dynamics (CFD) has proved to be a very useful tool to study nasal function. METHODS: We have used CFD software (the program MECOMLAND® and the Digbody® tool for virtual surgery) to investigate the behaviour of the parameters R-[Formula: see text] based on CFD results, when four subjects underwent virtual surgery to induce a septal perforation: two subjects with healthy noses and two patients suffering from nasal airway obstruction. For each case a CFD study was performed, before and after creating an anterior (close to nostrils) or a posterior (close to choanae) NSP. RESULTS: In all cases analyzed, a posterior septal perforation did not result in a significant volumetric flow rate [Formula: see text] through the perforation between nasal passages. However, for anterior defects only in those nasal cavities considered diseased or unhealthy, high values of [Formula: see text] were found. CONCLUSION: The induced NSP only rendered significant flow alterations in noses with preexisting nasal airway obstruction alterations, whereas in nasal cavities considered as normal the creation of a NSP did not produce significant differences between both sides. We strongly suggest that this finding can explain the variety of symptoms and the number of asymptomatic patients bearing NSP.

DigBody®: A new 3D modeling tool for nasal virtual surgery.

BACKGROUND AND PURPOSE: Recent studies have demonstrated that a significant number of surgical procedures for nasal airway obstruction (NAO) have a high rate of surgical failure. In part, this problem is due to the lack of reliable objective clinical parameters to aid surgeons during preoperative planning. Modeling tools that allow virtual surgery to be performed do exist, but all require direct manipulation of computed tomography (CT) or magnetic resonance imaging (MRI) data. Specialists in Rhinology have criticized these tools for their complex user interface, and have requested more intuitive, user-friendly and powerful software to make virtual surgery more accessible and realistic. In this paper we present a new virtual surgery software tool, DigBody®. METHODS: This new surgery module is integrated into the computational fluid dynamics (CFD) program MeComLand®, which was developed exclusively to analyze nasal airflow. DigBody® works directly with a 3D nasal model that mimics real surgery. Furthermore, this surgery module permits direct assessment of the operated cavity following virtual surgery by CFD simulation. RESULTS: The effectiveness of DigBody® has been demonstrated by real surgery on two patients based on prior virtual operation results. Both subjects experienced excellent surgical outcomes with no residual nasal obstruction. CONCLUSIONS: This tool has great potential to aid surgeons in modeling potential surgical maneuvers, minimizing complications, and being confident that patients will receive optimal postoperative outcomes, validated by personalized CFD testing.

New CFD tools to evaluate nasal airflow.

Computational fluid dynamics (CFD) is a mathematical tool to analyse airflow. As currently CFD is not a usual tool for rhinologists, a group of engineers in collaboration with experts in Rhinology have developed a very intuitive CFD software. The program MECOMLAND® only required snapshots from the patient's cross-sectional (tomographic) images, being the output those results originated by CFD, such as airflow distributions, velocity profiles, pressure, temperature, or wall shear stress. This is useful complementary information to cover diagnosis, prognosis, or follow-up of nasal pathologies based on quantitative magnitudes linked to airflow. In addition, the user-friendly environment NOSELAND® helps the medical assessment significantly in the post-processing phase with dynamic reports using a 3D endoscopic view. Specialists in Rhinology have been asked for a more intuitive, simple, powerful CFD software to offer more quality and precision in their work to evaluate the nasal airflow. We present MECOMLAND® and NOSELAND® which have all the expected characteristics to fulfil this demand and offer a proper assessment with the maximum of quality plus safety for the patient. These programs represent a non-invasive, low-cost (as the CT scan is already performed in every patient) alternative for the functional study of the difficult rhinologic case. To validate the software, we studied two groups of patients from the Ear Nose Throat clinic, a first group with normal noses and a second group presenting septal deviations. Wall shear stresses are lower in the cases of normal noses in comparison with those for septal deviation. Besides, velocity field distributions, pressure drop between nasopharynx and the ambient, and flow rates in each nostril were different among the nasal cavities in the two groups. These software modules open up a promising future to simulate the nasal airflow behaviour in virtual surgery intervention scenarios under different pressure or temperature conditions to understand the effects on nasal airflow.

[Evaluation of efficacy and clinical impact of positron emission tomography with 18F fluoro-deoxyglucose (FDG) in patients with suspicion of recurrent laryngeal carcinoma]. / Evaluación de la eficacia y el impacto clínico de la tomografía de emisión de positrones (PET) con 18F fluoro-desoxiglucosa (FDG) en pacientes con sospecha de recurrencia de carcinoma de laringe.

AIMS: To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent laryngeal carcinoma. MATERIALS AND METHODS: 15 patients, with suspicion of recurrent laryngeal carcinoma and ambiguous conventional imaging modalities. In all patients a whole body scan was performed with FDG-PET in fasting patients following i.v. administration of 370-444 MBq FDG. The results were confirmed by histology and clinical evolution (follow-up period > 12 months). RESULTS: Prevalence of recurrence was 86.6%. FDG-PET was positive in 13 patients, with confirmation in all cases, and 2 were true negative (TN). Overall sensitivity, specificity, PPV, NPV and accuracy were 100%. FDG-PET changed the modality of treatment in 10 patients (clinical impact 63.3%). CONCLUSIONS: FDG-PET has high clinical impact in patients with a suspicion of recurrent laryngeal carcinoma, and should be incorporated to the diagnostic protocols before making a therapy decision.

Extramuscular soft tissue myxoma of the lateral neck.

Myxomas are rare benign connective tissue tumours of unclear histogenesis. In this case a lateral neck tumour initially behaved, both clinically and radiographically as a lipoma, and was therefore managed conservatively. Subsequently the lesion caused pressure symptoms and therefore a surgical approach was taken with subsequent histology confirming a myxoma. Only five cases of soft tissue myxoma of the lateral neck have been reported in the English literature of which two were extramuscular. This is the largest reported myxoma of the head and neck region and was treated with simple enucleation. There has been no evidence of recurrence five years after surgery.

[Massive hyperplasia of the arytenoid mucosa with sleep apnea and stridor. Endoscopic resection by CO2 laser]. / Hiperplasia gigante de la mucosa aritenoidea con apnea del sueño y estridor. Resección endoscópicacon láser CO2*

A case is presented of a 48 year-old woman with symptoms of severe rhoncopathy and obstructive sleep apnea, followed by middle inspiratory stridor and dyspnea to any phisial effort. Redundant hyperplasia of the arytenoid mucosa was discovered during exploration, with vibration during inspiration and closure of the lumen as it goes closer to the epiglottis. Also, severe septal deviation, hypertrophy of the pharyngeal tonsil, soft palate and uvula, and macroglossia, were diagnosed. Neither CPAP/BIAP or triple anti-reflux therapy were effective, and laser endoscopic excision resolved the laryngeal obstruction. Currently the stridor has disappeared, whereas rhoncopathy is improved with low pressure CPAP. Pathogenesis of the giant hyperplasia of the arytenoid mucosa of unknown origin is discussed, as literature search revealed only three cases reported worldwide.

[Controversial aspects of verrucous carcinoma of the larynx: viral etiology, diagnosis and treatment]. / Aspectos controvertidos del carcinoma verrucoso de laringe: etiología viral, diagnóstico y tratamiento.

Verrucous carcinoma is a clinical and pathological entity which was recognized only in recent years. The laryngologist and pathologist must cooperate closely to formulate a correct diagnosis, because the microscopical findings may not show cytological criteria for malignancy, whereas the clinical behaviour is locally invasive. Suitable treatment remains controversial, as radiotherapy does not only control the tumour but may be followed by anaplastic transformation. There is increasing evidence of human papillomaviruses as etiologic agents, although further studies to determine their precise role in carcinogenesis are needed.

[Carcinoma of the laryngeal ventricular saccule as an anatomo-clinical entity]. / El carcinoma del sáculo ventricular laríngeo como entidad anatomoclínica.

The relationship between laryngocele and laryngeal carcinoma has already been well established. A distinct entity is the carcinoma arising from the ventricular saccule or a preexisting laryngocele showing a peculiar clinical behavior and pathological features. We present here a case of ventriculosaccular carcinoma of the larynx, discussing the clinical presentation and the immunohistochemical analysis performed using monoclonal antibodies, and the factors which might modulate the aggressiveness of the neoplasm.

[The problems posed by nasosinusal chondrosarcoma: a review of the literature and a case report]. / Problemas que plantea el condrosarcoma nasosinusal: revisión de la literatura y presentación de un caso.

Presenting the case of a massive chondrosarcoma arising from the nasal cavity. The related literature comprises less than 150 chondrosarcomas originated on the facial skeleton. The AA. discuss the protean manifestations of this kind of tumor and emphasize the aggressive therapy required. Correlation is made with the existing body of information regarding this entity.

[Airway obstruction caused by a lymphoid polyp of the palatine tonsil]. / Obstrucción de la vía aérea producida por pólipo linfoide de la amígdala palatina.

We report a case of airway obstruction in an adult patient due to a lymphoid polyp of the palatine tonsil. We discuss some aspects of etiopathogenesis and differential diagnosis of this uncommon tumour.