Total trans-oral endoscopic thyroidectomy and cervical lymphadenectomy: a human cadavers surgery study / 中华外科杂志

<p><b>OBJECTIVE</b>To find an approach for trans-oral endoscopic thyroidectomy (TOET) and cervical lymphadenectomy using conventional endoscopic surgical instruments on frozen fresh cadavers.</p><p><b>METHODS</b>Six frozen fresh cadavers were used in three groups of trans-oral trocar installation experiments: oral vestibule installation, sublingual region installation, and combined bi-vestibular and sublingual installation. TOET (with pretrachealis method to thyroid fixation removal) and cervical lymphadenectomy were performed experiments on another 6 frozen fresh cadavers using the best access approach found in the aforementioned experiments.</p><p><b>RESULTS</b>In oral vestibule trocar installations, the trocars caused large lacerated wound and damaged air tightness. In sublingual installations, only one trocar could be installed in the sublingual area because the space in sublingual area was limited. In combined bi-vestibular and sublingual installations, no gland, vessel or nerve was damaged. Combined bi-vestibular and sublingual access were selected as the surgical approach on the basic of analysis the merits of each approach. TOET and cervical lymphadenectomy in area III, IV, VI, VII were performed without making any accessory damage through combined bi-vestibular and sublingual access approach.</p><p><b>CONCLUSIONS</b>TOET is feasible. Combined bi-vestibular and sublingual approach is available for TOET. Part of the cervical lymph nodes could be resected. Pretrachealis approach to thyroid fixation removal can still be used.</p>

Mechanism of radiosensitization of 3-methyladenine in human hypopharynx cancer cells / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the radiosensitizing effect and its mechanism of 3-MA in human hypopharynx cancer cells.</p><p><b>METHODS</b>5 mmol/L of 3-MA combined with 2 Gy or 4 Gy of X-ray was utilized to deal with Fadu cells, and the cell livability (cloning efficiency) and DNA lesion severity (tail moment) of each groups was examined by clonogenic survival assay and comet assay, then differences were compared between groups by independent-sample T test. Fadu cells were then treated with different dose of 3-MA (1, 2, 5, 10 mmol/L), the alteration of cell cycle distribution was detected by flow cytometer, and differences among groups were analyzed through one-way analysis of variance. The expression of p62 and cyclinB1 in each group was examined by western blot.</p><p><b>RESULTS</b>The livability and DNA lesion severity of cells treated with 3-MA alone showed no notable variation. Compared with non-3-MA groups, the cloning efficiency of cells treated with 3-MA decreased much more after irradiated with 2 Gy or 4 Gy of X-ray (t = 13.41 or 13.98, P < 0.001), and the cells showed a more serious DNA lesion (t = 7.07 or 6.91, P < 0.001). The G2/M percentages of cells in the control group and groups treated with 1, 2, 5, 10 mmol/L of 3-MA were 17.10 ± 1.20, 23.30 ± 2.3, 39.90 ± 3.12, 58.47 ± 1.65, 76.13 ± 3.51 and differences among groups were statistically significant (F = 278.4, P < 0.05). The expression of p62 in cells treated with 3-MA showed a dose-dependent increase, while cyclinB1 showed a dose-dependent decrease.</p><p><b>CONCLUSIONS</b>The autophagy inhibitor 3-MA could enhance radiosensitivity of human hypopharynx cancer cells by inducing G2/M arrest and enhancing irradiation-induced DNA damage.</p>

Surgical anatomy of totally trans-oral video-assisted thyroidectomy / 中华外科杂志

<p><b>OBJECTIVE</b>To define the anatomical approach, anatomical planes and related vessels and nerves to create a safe and reproducible combined sublingual and bi-vestibular access for trans-oral video-assisted thyroidectomy.</p><p><b>METHODS</b>From November 2009 to May 2011, twenty-five embalmed human specimens were dissected for anatomical information of the cervical region, the mandible region and the supra-hyoid muscles. On twenty fresh frozen human specimens after an experimental trans-oral endoscopic thyroidectomy, the related vascular, neural structures and muscles were evaluated.</p><p><b>RESULTS</b>The optical access port was placed in the midline sublingual. The geniohyoid muscle, mylohyoid muscle and the anterior belly of the digastric muscle were divided in the midline in order to reach the plane under the platysma muscle. The mucosa was sagittal incised bilaterally in the vestibular of oral cavity for working trocar, at the level of the first molar of the mandible. The working trocar reached directly the periosteum of the mandible, under the facial vessel and the marginal branch of facial nerve, and then passed below the platysma muscle into the infra-laryngeal working area. The distance from mental nerve to mandibular midline and between mental nerve and facial artery were (25.8 ± 0.9) mm and (29.4 ± 0.9) mm respectively. Anatomical dissections showed that after an experimental trans-oral combined sublingual and bi-vestibular access, all muscles of the floor of the oral cavity as well as the related vascular and neural structures are intact. The maximum nodule size of the resected specimens in the totally trans-oral approach was up to 50 mm.</p><p><b>CONCLUSION</b>The combined sublingual and bi-vestibular access of trans-oral video-assisted thyroidectomy is safe and reproducible.</p>