Endoscope

The VATS resection was performed using the uniportal technique. The patients were intubated with a double lumen endotracheal tube and placed in the lateral decubitus position. A utility incision measuring approximately 3–5 cm was performed from the 5. intercostal space in the anterior position. No rib retractor was used. A 10 mm 30-degree thoracoscope (Karl Storz endoscope; Karl Storz, Tuttlingen, Germany) was used to provide a panoramic appearance and it was placed in the anterior part of the incision. Dissecting and holding clamps used in open surgery were placed through the dorsal part of the utility incision. The surgeon was at the anterior side of the patient. First, the pleural space was evaluated for suitability of thoracoscopic anatomical resection.
The dense adhesions between the lung and thorax wall were released through the aid of a small peanut-gauze, spatula-shaped electrocautery and electro-thermal bipolar tissue sealing system (Ligasure, Valleylab Inc., USA) (Photo 2). Pulmonary vessels and bronchi were dissected by an endoscopic linear cutter (Endo GIA, Covidien, USA) (Photos 3 A–C). The specimen was taken out of the incision with the aid of a protective endobag for preventing contamination. After meticulous air leak and hemorrhage control, the thorax was closed with a single chest drain placed through the posterior part of the incision (Photo 3 D).

The right or left lateral decubitus position was given to the patients according to the planned surgical procedure. For the mediastinal mass biopsy, a 30° supine position with a back support pad was given. In each patient, a single 2-cm incision was opened as standard, and exploration was performed with a 5-mm 30° thoracoscope camera (Karl Storz endoscope; Karl Storz, Tuttlingen, Germany). When necessary, a second incision was opened and the operation was completed biportally. Endo grasper, endo cautery, endo dissector, and surgical energy devices were used as surgical instruments. At the end of the operation, Hemovac drainage or thorax drains were placed in the thorax according to the surgeon’s preference.

Clinical data, including sex, age, intraductal stone treatment history, involved sides, number of stones in the same gland, palpation, CBCT images (New Tom Inc., Italy), and results of endoscopic removal were collected for the patients who met the criteria. The average location, transverse diameter (TD) and longitudinal diameter (LD) of all the stones on CBCT images were recorded after evaluation by 3 blinded experienced surgeons. As demonstrated in Figure 2, the location of the stone was defined as the distance between its anterior edge and the midpoint of the glossal bony cortex of the mandible in axial CBCT views. The TD of the stone was defined as the maximum width on its axial, coronal and sagittal sections. The LD of the stone was defined as its maximum length on the axial CBCT views. We attempted to remove all of the stones included in our study with forceps or baskets after locating them with an endoscope (Karl Storz Inc., Germany), as shown in Figure 3. All endoscopic removals were performed by the same three experienced surgeons (Q.T., G.L., and H.L.).

This study was approved by the Institutional Review Board of Peking University First Hospital.
The anatomical dissections were conducted at the anatomy center in Peking University First Hospital. The specimens were collected from voluntary body donations to the Peking University First Hospital. In our study, we used 14 sides of SLA from heads of seven adult male fresh‐frozen and silicone‐injected cadavers with no history of trauma, surgery, and congenital malformation.
Transoral dissections were assisted by an endoscope (Karl Storz, Tuttlingen, Germany), suspension laryngoscope including the duck‐billed and Feyh‐Kastenbauer suspension laryngoscope, and microdissection instruments.