Plastinated nasal model: a new concept of anatomically realistic cast.

BACKGROUND: For many years, researchers have been interested in investigating airflow and aerosol deposition in the nasal cavities. The nasal airways appear to be a complex geometrical system. Thus, in vitro experimental studies are frequently conducted with a more or less biomimetic nasal replica. AIM: This study is devoted to the development of an anatomically realistic nose model with bilateral nasal cavities, i.e. nasal anatomy, airway geometry and aerodynamic properties as close as possible to in vivo behaviour. METHODS: A specific plastination technique of cephalic extremities was developed by the Anatomy Laboratory at the Saint-Etienne University in the last 10 years. The plastinated models obtained were anatomically, geometrically and aerodynamically validated using several techniques (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). RESULTS: Our plastination model exhibited a high level of anatomic quality, including a very good mucosa preservation. Aerodynamical and geometrical investigations highlighted a global behaviour of plastinated models perfectly in accordance with a nasal decongested healthy subject. CONCLUSIONS: The present plastination model provides a realistic cast of nasal airways, and may be a useful tool for nasal flow, drug delivery and aerosol deposition studies.

[Prognostic factors of invasive bladder cancer with lymph node invasion]. / Facteurs pronostiques des cancers infiltrants de vessie avec envahissement lymphonodal.

OBJECTIVE: To identify the prognostic factors influencing survival and to assess the value of extensive lymphadenectomy in invasive bladder cancer with lymph node invasion. MATERIAL AND METHODS: The medical records of 62 patients treated by cystectomy with curative lymphadenectomy for invasive bladder cancer with lymph node invasion were reviewed. Thirty four patients had lymph node dissection ascending at least as far as the common iliac vessels, 26 had pelvic lymph node dissection and 2 had simple lymph node biopsies. RESULTS: The 2-, 3- and 5-year actuarial survival rates were 37%, 26.6% and 23.6%, respectively, with a median survival of 18.4 months. This study appears to show the independent prognostic value of the following factors: tumour strictly confined to the bladder (< or = pT3a) (p = 0.002), < or = 2 invaded lymph nodes (p = 0.001), N1 lymph node stage (p = 0.009). Extensive lymphadenectomy would not provide any benefit in terms of survival compared to simple pelvic lymph node dissection (p = 0.8). Common iliac node invasion appears to be a factor of poor prognosis when the tumour extends beyond the bladder (> pT3a) (p = 0.018). CONCLUSION: In these patients with invasive bladder cancer and lymph node invasion, a number of invaded lymph nodes < or = 2 and local stage < or = pT3a appear to be favourable prognostic factors resulting in a 23.6% remission rate (56.8% when both factors were present simultaneously) after cystectomy plus lymphadenectomy. Extensive lymphadenectomy including the common iliac vessels would not improve survival compared to pelvic lymph node dissection, but nevertheless appears us to be justified, as the presence of common iliac lymph node invasion constitutes a significant and powerful prognostic factor to recommend adjuvant therapy.

Impact of acoustic airflow nebulization on intrasinus drug deposition of a human plastinated nasal cast: new insights into the mechanisms involved.

PURPOSE: The impact of 100 Hz (Hertz) acoustic frequency airflow on sinus drug deposition of aerosols was investigated using a human plastinated nasal cast. The influence of drug concentration and endonasal anatomical features on the sinus deposition enhanced by the 100 Hz acoustic airflow was also examined. METHODS: Plastinated models were anatomically, geometrically and aerodynamically validated (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). Using the gentamicin as a marker, 286 experiments of aerosol deposition were performed. Changes of airborne particles metrology produced under different nebulization conditions (100 Hz acoustic airflow and gentamicin concentration) were also examined. RESULTS: Aerodynamic and geometric investigations highlighted a global behaviour of plastinated models in perfect accordance with a nasal decongested healthy subject. The results of intrasinus drug deposition clearly demonstrated that the aerosols can penetrate into the maxillary sinuses. The 100 Hz acoustic airflow led to increase the deposition of drug into the maxillary sinuses by a factor 2-3 depending on the nebulization conditions. A differential intrasinus deposition of active substance depending on maxillary ostium anatomical features and drug concentration was emphasized. CONCLUSION: The existence of a specific transport mechanism of penetration of nebulized particles delivered with acoustic airflow was proposed.