[Leiomyoma of the esophagus : A further indication for robotic surgery?] / Das Leiomyom des Ösophagus : Eine weitere Indikation für den Roboter?

BACKGROUND: Leiomyomas of the esophagus are rare tumors but the most common benign lesion of the esophagus originating from smooth muscle cells. The symptoms are mainly determined by the size of the tumor and are caused by dysphagia and/or retrosternal pain. The majority of patients are however asymptomatic. The diagnostics include esophagoscopy, endosonography and chest computed tomography. Surgery is considered the treatment of choice and ideally involves enucleation of the tumor but may lead to esophagectomy. In addition to the classical open procedures, minimally invasive procedures are also used. Regardless of the selected procedure, a lesion of the mucosa should be avoided. OBJECTIVE: A review of the literature on thoracoscopic and robotic resections in the treatment of leiomyomas was carried out and an illustration of a clinical case is presented. MATERIAL AND METHODS: A review of minimally invasive surgical treatment of esophageal leiomyomas is presented. The literature search was carried out in PubMed for publications of thoracoscopic and robotic-assisted thoracic enucleation of leiomyomas of the esophagus. In addition, the robotic-assisted thoracic enucleation of a horseshoe-shaped leiomyoma in the middle third of the esophagus is described. RESULTS: The enucleation of the esophageal leiomyoma was carried out through a right-sided robotic-assisted operation with one lung ventilation. The surgery time was 143 min. There were no intraoperative or postoperative complications. On the 3rd postoperative day a light diet was started and the thorax drainage was removed. Histopathology confirmed a leiomyoma. The patient was discharged on the 5th postoperative day and free of complaints. CONCLUSION: Robotic-assisted surgery for leiomyomas of the esophagus is a safe procedure. Taking the available data into account, robotic-assisted thoracic enucleation of leiomyomas was characterized by less mucosal lesions, general complications and a lower conversion rate as well as a shorter hospital stay compared to classical thoracoscopic enucleation. Thus, robotic-assisted surgery can be the method of choice for leiomyomas of the esophagus.

Manipulating the magnetic structure of Co core/CoO shell nanoparticles: implications for controlling the exchange bias.

We present an experimental study of the effects of oxidation on the magnetic and crystal structures of exchange biased epsilon-Co/CoO core-shell nanoparticles. Transmission electron microscopy measurements reveal that oxidation creates a Co-CoO interface which is highly directional and epitaxial in quality. Neutron diffraction measurements find that below a Néel temperature TN of approximately 235 K the magnetization of the CoO shell is modulated by two wave vectors, q1=(1/2 1/2 1/2)2pi/a and q2=(100)2pi/a. Oxidation affects the q1 component of the magnetization very little, but hugely enhances the q2 component, resulting in the magnetic decompensation of the core-shell interface. We propose that the large exchange bias effect results from the highly ordered interface between the Co core and CoO shell, and from enhanced core-shell coupling by the uncompensated interface moment.