2.1 Skin preparation, clean the umbilicus,bowel preparation should be done before operative. Effective cleaning of the umbilicus can effectively avoid intraoperative and postoperative infections. All patients signed the informed consent form and voluntarily requested LESS surgery or traditional laparoscopic surgery.
2.2 Surgical process Experimental cohort : After general anesthesia, the patient was placed in the dorsal lithotomy position and had an indwelling catheter.A 2.5 cm longitudinal vertical incision was made in the umbilicus, the skin and subcutaneous tissue were incised, the peritoneum was opened into the abdominal cavity, and a single-port laparoscopic incision retractor was placed under direct vision. The device consists of three components: introducer, fixed valve, and cannula. After the completion of the device, a CO2 tube was connected to maintain the pneumoperitoneum pressure at 12 mmHg, and a laparoscopic lens was carefully placed for abdominal exploration. Ovarian cysts, ovaries, peritoneal surface, greater omentum, appendix, abdominopelvic adhesions, and ascites were explored as can as possible. During exploration, should pay attention to gentle movement to avoid puncturing the cyst. After ruling out the surgical contraindications, the removable port cover of the device was removed and extracorporeal ovarian cystectomy was operated. The inner edge of the wound retractor was covered with sterile gauze, the cyst surface was sutured with purse-string suture and then slowly lifted upwards, the tissue scissors were used to puncturing the central depression of the tissue, and the cyst fluid was aspirated with vacuum suction system, during which also should to exploring whether the cyst was multilocular, and whether the cyst contained solid components. After cyst reduction, the cyst wall was stripped while pulling it out of the abdominal cavity (Picture A). Part of the dissected tissue was taken and sent for frozen pathology and the results were awaited during surgery. If the pathological results suggested that it was benign, ovarian repair was performed, the ovary was sutured into a long strip to facilitate passage through the small abdominal incision. After the ovary was delivered into the pelvis, the single-port laparoscopic port was reset and the abdominal cavity was carefully observed to determine any bleeding spots and other lesions with under laparoscopic lens. The pelvic and abdominal cavity was irrigated with a large amount of normal saline, and the abdominal wall incision was sutured (Picture B).If the patient required adnexectomy or other operations on the basis of preoperative conversation or intraoperative frozen section diagnosis, the completely collapsed ovarian cyst was returned to the abdominal cavity and other surgical procedure was performed.
Control cohort : Surgery was performed under general anesthesia, as in the LESS surgery all patients were in the dorsal lithotomy position and all had an indwelling catheter. A transverse incision of about 12 mm in length was made at the upper edge of the umbilicus or at the appropriate site of the upper abdomen which depended on the size of the cyst, with a trocar was placed in. Before connecting the CO2 tube, the laparoscopic lens should be placed into this puncture tube to ensure that tube enters the abdominal cavity, thereby avoiding the formation of subcutaneous emphysema. After the formation of pneumoperitoneum, the abdominal cavity, omentum, and peritoneum were checked under Laparoscopic to exclusion surgical contraindications. After that two 5 mm trocars were placed in the avascular area of the left lower abdomen, and 5 mm and 12 mm trocars were placed in the right. Place the disposable surgical specimen extraction bag under laparoscopic monitoring, moved the ovarian cyst into the bag, pull the opening of the bag with atraumatic forceps to give a certain tension. A monopolar electric hook is used to make an incision on the surface of ovarian cyst. At the same time, the aspirator enters the cyst cavity through the incision to suck the cyst fluid. Ovarian cysts were carefully dissected, in this process, whether the cyst cavity is multilocular and whether there is a solid component should also be checked. The remaining ovarian tissue was sutured with absorbable sutures after complete dissection of the ovarian cyst. Tighten the bag, clamp it with atraumatic forceps, remove the 12 mm trocar in the right lower abdomen, and dragged the opening of the bag to the outside of the abdominal cavity through this puncture hole. Ensure that the opening of the collection bag has been completely pulled out of the abdominal cavity, relax the band and carefully take out the specimen with oval forceps. Pull the collection bag while removing the specimen. Finally, the collection bag is also taken out through the puncture hole. After that, check the integrity of the collection bag again. This process is completed under laparoscopic monitoring to observe whether the bag is damaged. It needed to reduce the CO2 pneumoperitoneum pressure to give a elasticity to the abdominal wall, which adds some difficulties to laparoscopic monitoring. Specimens were sent for frozen pathology, if benign, the pelvis was irrigated with normal saline, and after determining the absence of active bleeding, the procedure was ended routinely. If the patient required adnexectomy or other operations on the basis of preoperative conversation or intraoperative frozen section diagnosis, after the cysts fluid is absorbed, other surgical procedures were performed directly
2.3 Statistical data
Operation-related indicators were recorded, including operation time (min), intraoperative blood loss (ml), sac fluid spillage rate, postoperative analgesic drug application, postoperative first exhaust time (h), and postoperative hospital stay (d). Perioperative complications were recorded, including fever, poor incision healing, incisional hernia, intestinal obstruction, and pelvic inflammatory disease, ect.
2.4 Statistical Methods
SPSS 23.0 software was applied for statistical analysis. Categorical variable data are expressed as frequency (percentage).Continuous variable data are expressed as median (interquartile range [IQR]) or mean ± standard deviation (‾X ± SD) after verification that the data are normally distributed. Basic information, surgical results, and postoperative pathology were compared between the two cohorts, using the t-test, Fisher's exact test, χ2 test, or Mann-Whitney U test. P < 0.05 was considered as statistically significant.