Surgical management of laryngotracheal stenosis in adults

The purpose was to evaluate the outcome following the surgical management of a consecutive series of 26 adult patients with laryngotracheal stenosis of varied etiologies in a tertiary care center. Of the 83 patients who underwent surgery for laryngotracheal stenosis in the Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Lausanne, Switzerland, between 1995 and 2003, 26 patients were adults (≥16years) and formed the group that was the focus of this study. The stenosis involved the trachea (20), subglottis (1), subglottis and trachea (2), glottis and subglottis (1) and glottis, subglottis and trachea (2). The etiology of the stenosis was post-intubation injury ( n =20), infiltration of the trachea by thyroid tumor ( n =3), seeding from a laryngeal tumor at the site of the tracheostoma ( n =1), idiopathic progressive subglottic stenosis ( n =1) and external laryngeal trauma ( n =1). Of the patients, 20 underwent tracheal resection and end-to-end anastomosis, and 5 patients had partial cricotracheal resection and thyrotracheal anastomosis. The length of resection varied from 1.5 to 6cm, with a median length of 3.4cm. Eighteen patients were extubated in the operating room, and six patients were extubated during a period of 12 to 72h after surgery. Two patients were decannulated at 12 and 18months, respectively. One patient, who developed anastomotic dehiscence 10days after surgery, underwent revision surgery with a good outcome. On long-term outcome assessment, 15 patients achieved excellent results, 7 patients had a good result and 4 patients died of causes unrelated to surgery (mean follow-up period of 3.6years). No patient showed evidence of restenosis. The excellent functional results of cricotracheal/tracheal resection and primary anastomosis in this series confirm the efficacy and reliability of this approach towards the management of laryngotracheal stenosis of varied etiologies. Similar to data in the literature, post-intubation injury was the leading cause of stenosis in our series. A resection length of up to 6cm with laryngeal release procedures (when necessary) was found to be technically feasibl

Estimation of long memory in the presence of a smooth nonparametric trend

We consider semi parametric estimation of the long-memory parameter of a stationary process in the presence of an additive nonparametric mean function. We use a semi parametric Whittle type estimator, applied to the tapered, differenced series. Since the mean function is not necessarily a polynomial of finite order, no amount of differencing will completely remove the mean. We establish a central limit theorem for the estimator of the memory parameter, assuming that a slowly increasing number of low frequencies are trimmed from the estimator's objective function. We find in simulations that tapering and trimming are essential for the good performance of the estimator in practice.Statistics Working Papers Serie

Meyer's surgical procedure for the treatment of lip carcinoma

Lip carcinomas are generally treated by surgery. A reconstruction is often required if the resected segment exceeds one-third of the lip. Meyer's plasty is an alternate way of reconstructing the lower or upper lip. The aim of this study is to describe the technique, its indications and results. A retrospective review of all patients who underwent a Meyer's plasty in our institution is presented. Twenty-four consecutive patients were treated in Lausanne for T1 and T2 lip carcinomas between 1983 and 2001. Primary surgery associated with Meyer's plasty was performed in all cases. Data were collected from the medical records, and eight patients were recalled for clinical evaluation. The oncological, functional and aesthetic results were analyzed. The 5-year local control was 100%. Three patients developed metachronous lymph node metastasis. No patient died from the disease. A hindering microstomy was found in three cases, and two patients suffered from temporary oral leakage. No speech difficulty was encountered. The aesthetics was described as satisfying or good in 87% of the patients. Meyer's plasty following lip surgery of the upper or lower lip allows an aesthetic and functional one-stage reconstruction without compromising the oncological outcom

An Agent-Based Framework for Urban Mobility Simulation

International audienceMobility study is composed of many research areas which one interests us: urban mobility. In the literature, urban mobilities are represented by analytical techniques like stochastic laws or they are defined by simulation tools like Multi-Agents Systems (MAS). The goal of our work is to define citizen behaviour in order to observe population dynamics by a simulation. This strategy is facilitated by a meta-model and a toolkit which are used with a particular method. The latter begins by a conceptual representation of each mobile and finishes by a mobility simulator. This paper aims at describing the mobility simulation toolkit. Thanks to this framework, mobility simulator development is sim- plified. It allows us to create distributed applications which are based on MAS

The role of the CO2 laser in the management of laryngotracheal stenosis: a survey of 100 cases

Over the last decade, improvement of CO2 lasers with the microspot and ultrapulse technologies has broadened the indications for endoscopic CO2-laser resection of benign laryngotracheal stenosis (LTS). This article reviews 100 patients treated solely by endoscopic means for a LTS. There were 47 grade III, 41 grade II and 12 grade I stenoses according to the Myer-Cotton classification. The postoperative results show that the improvement to a nearly normal (>80% luminal size) airway declines from 92% (11/12 patients) for grade I to 46% (19/41 patients) for grade II and 13% (6/47 patients) for grade III stenoses. When compared to open surgery for more severe grades of stenosis (31 grade IV, 66 grade III and 3 grade II stenoses), the results of the endoscopy group is much less favorable: 36% of patients in the endoscopy group versus 76% of patients in the open surgery group were rehabilitated to a normal respiration without exertional dyspnea and 38% versus 5% patients remained tracheotomy dependent. However, if strict selection and therapeutic criteria are respected, a significant number of grade I and II stenoses, and to a lesser degree of grade III stenoses, can be improved to a nearly normal airway by endoscopic means only. The endoscopic treatment is potentially less invasive and risky and only needs a short hospital stay. To try this as a first treatment modality in a selected group of patients is worthwhile, provided that this endoscopic treatment is not repeated a second time, if the stenosis recurs to its initial grade after a primary CO2-laser treatment. Some guidelines for safe endoscopic treatment modalities with of the CO2 laser, dilatation and/or stenting are propose