The effect of nasal shape on the thermal conditioning of inhaled air: Using clinical tomographic data to build a large-scale statistical shape model.

In this paper, we investigate the heating function of the nasal cavity qualitatively, using a high-quality, large-scale statistical shape model. This model consists of a symmetrical and an asymmetrical part and provides a new and unique way of examining changes in nasal heating function resulting from natural variations in nasal shape (as obtained from 100 clinical CT scans). Data collected from patients suffering from different nasal or sinus-related complaints are included. Parameterized models allow us to investigate the effect of continuous deviations in shape from the mean nasal cavity. This approach also enables us to avoid many of the compounded effects on flow and heat exchange, which one would encounter when comparing different patient-specific models. The effects of global size, size-related features, and turbinate size are investigated using the symmetrical shape model. The asymmetrical model is used to investigate different types of septal deviation using Mladina's classification. The qualitative results are discussed and compared with findings from the existing literature.

Matlab® toolbox for semi-automatic segmentation of the human nasal cavity based on active shape modeling.

The nose is a complex and important organ with a multitude of functions. Computational fluid dynamics (CFD) has been shown to be a valuable tool to obtain a better understanding of the functioning of the nose. CFD simulations require a surface geometry, which is constructed from tomographic data. This can be a very time-consuming task when one chooses to exclude the sinuses from the simulation domain, which in general keeps the size of the CFD model more manageable. In this work, an approach for the semi-automatic construction of the human nasal cavity is presented. In the first part, limited manual interaction is needed to create a coarse surface model. In the next part, this result is further refined based on the combination of active shape modeling with elastic surface deformation. The different steps are bundled in a Matlab toolbox with a graphical interface which guides the user. This interface allows easy manipulation of the data during intermediate steps, and also allows manual adjustments of the reconstructed nasal surface at the end. Two results are shown, and the approach and its precision are discussed. These results demonstrated that the followed approach can be used for the semi-automatic segmentation of a human nasal cavity from tomographic data, substantially reducing the amount of operator time.

Association between children's emotional/behavioral problems before adenotonsillectomy and postoperative pain scores at home.

BACKGROUND: Children undergoing adenotonsillectomy are at risk of severe postoperative pain and sleep problems. Little is known about the specific child risk factors for these problems. AIMS: The aim of this study was to assess the occurrence of postoperative pain, sleep problems, and medication adherence, and assess the influence of internalizing and externalizing problems on postoperative pain. METHODS: This prospective cohort study included 160 children, aged 1.5-5 years undergoing day-care adenotonsillectomy. Parents rated their child's pain with the Parents' Postoperative Pain Measure and their child's sleep problems with Vernon's Post Hospital Behavioral Questionnaire during the first 3 days and at day 10 postoperatively. Emotional/behavioral problems (ie, internalizing and externalizing behaviors) during the past 2 months were assessed using the Child Behavior Checklist. Regression analysis was used to assess whether children's pain intensity at home was associated with internalizing/externalizing problems, after controlling for age, preoperative child state anxiety, parental state anxiety, parental need for information, and socioeconomic status. RESULTS: Applying a threshold of ≥6 on the Parents' Postoperative Pain Measure, the incidence of moderate to severe pain was 57.6% at day 1, 53.5% at day 2, 35.4% at day 3, and 4.8% at day 10. During the first three postoperative nights, 37.1% of the children woke up. Internalizing problems (ß = 0.343; P = 0.001) and parental need for information (ß = 0.207; P = 0.011) were independently associated with higher pain scores at home during the first 3 days (R2 = 0.225). CONCLUSION: Following adenotonsillectomy, children often experienced moderate to severe pain and sleep problems during the first 3 days at home. Preoperative internalizing problems and parental need for information were independently associated with increased pain at home. Screening for these problems can help to identify vulnerable children and adapt the perioperative analgesic strategy accordingly (which includes preparation, information, and prescription of pain analgesics).

High quality statistical shape modelling of the human nasal cavity and applications.

The human nose is a complex organ that shows large morphological variations and has many important functions. However, the relation between shape and function is not yet fully understood. In this work, we present a high quality statistical shape model of the human nose based on clinical CT data of 46 patients. A technique based on cylindrical parametrization was used to create a correspondence between the nasal shapes of the population. Applying principal component analysis on these corresponded nasal cavities resulted in an average nasal geometry and geometrical variations, known as principal components, present in the population with a high precision. The analysis led to 46 principal components, which account for 95% of the total geometrical variation captured. These variations are first discussed qualitatively, and the effect on the average nasal shape of the first five principal components is visualized. Hereafter, by using this statistical shape model, two application examples that lead to quantitative data are shown: nasal shape in function of age and gender, and a morphometric analysis of different anatomical regions. Shape models, as the one presented here, can help to get a better understanding of nasal shape and variation, and their relationship with demographic data.

Free jejunal autograft reconstruction after total pharyngolaryngeal resection.

A free jejunal autograft reconstruction after debulking high stage larynx and hypopharynx tumors has become a popular method in our 10-year experience. We retrospectively studied the efficacy and outcome. Nine patients (M/F, 8/1) underwent a total of 10 free jejunal autograft reconstructions. The median age was 58.6 years (range, 48-78 years). The median hospital stay was 32 days (range, 13-67 days) and the graft failure rate was 10% (1/10), 9/10 successfully retransplanted. Postoperative mortality rate was 0%; one patient was lost during follow-up, one patient died of lung cancer, three died of local recurrence, and four patients have no evidence of disease at this moment (mean follow-up of 16.5 months; range, 9-41 months). Salivation fistulas were present postoperatively in four patients: one closed spontaneously and three closed after surgery. In our hands, the free jejunal graft is the preferred method for single-stage reconstruction of circumferential defects of the gullet.