[The application of temporalis muscle flap in the salvage nasopharyngectomy for advanced recurrent nasopharyngeal carcinoma].

Objective: To summarize the application of temporalis muscle flap in the salvage nasopharyngectomy for advanced recurrent nasopharyngeal carcinoma (rNPC), and to provide guidance for the repair of extensive skull base defects in salvage rNPC. Methods: A total of 54 patients with the application of temporalis muscle flap in the salvage nasopharyngectomy for advanced rNPC were retrospectively analyzed, including 42 males and 12 females, aging from 29 to 71 years. There were 36 patients with rT3 and 18 patients with rT4. The surgical methods of temporalis muscle flap repair were summarized. The general situation, survival time and postoperative complications of patients were recorded, and the advantages and disadvantages of temporalis muscle flap were discussed. Results: The temporal muscle flap could completely cover the defect area of nasopharynx and skull base, without the need for other autologous repair materials. The follow-up period was 2 to 28 months. The survival rate of temporalis flap was 98.1% (53/54). The 1-year overall survival rate was 84.5% while 1-year progression-free survival rate was 49.0%. None of the patients had facial nerve injury. Three patients (5.6%) had necrosis of the cranial membrane required surgical intervention and four patients (7.4%) required a chonoplasty due to severe chonostril stenosis or chonostril atresia. Eleven cases (20.4%) had mouth opening restriction, chewing weakness, dysphagia and other eating difficulties. Conclusions: Temporalis muscle flap is an alternative flap for the salvage nasopharyngectomy for advanced rNPC. Temporal muscle flap shows high survival rate and wide coverage, but the surgeon should apprehend the possible complications and reduce the occurrence of them.

Fluoride removal from brackish groundwater by direct contact membrane distillation.

The direct contact membrane distillation (DCMD) applied for fluoride removal from brackish groundwater is presented. The self-prepared polyvinylidene fluoride membrane exhibited high rejection of inorganic salt solutes and a maximum permeate flux 35.6 kgm(-2) h(-1) was obtained. The feed concentration had no marked impact on the permeate flux and the rejection of fluoride. The precipitation of CaCO3 would clog the hollow fiber inlets and foul the membrane surface with the increase of concentration factor when natural groundwater was used directly as the feed, which resulted in a rapid decline of the module efficiency. This phenomenon was diminished by acidification of the feed. The experimental results showed that the permeate flux and the quality of obtained distillate kept stable before concentration factor reached 5.0 with the acidified groundwater as feed. The membrane module efficiency began to decline gradually when the feed continued to be concentrated, which can be mainly attributed to the formation of CaF2 deposits on the membrane surface. Finally, a 300 h continuous fluoride removal experiment on acidified groundwater was carried out with concentration factor at 4.0, the permeate flux kept stable and the permeate fluoride was not detected.