1. . In this study, if the length of the auxiliary incision is more than 10 cm, it is considered a conversion to open surgery.
2. .The number of all patients treated with surgery as the denominator and the number of the patients with conversion to open surgery as the numerator are used to calculate the proportions.

1. . The investigators confirm the surgical margin status by postoperative pathology report.
2. . The number of all patients treated with surgery as the denominator and the number of the patients with positive surgical margin as the numerator are used to calculate the proportions.

1. . Incidence of postoperative major complications: The standard for postoperative major complications refers to the short-term complications according to the Clavien-dindo grade, IIIA level and above for serious complications, and when multiple complications occur simultaneously, the highest ranked complication is the subject.
2. . Postoperative complications are divided into short-term complications after surgery and long-term complications after surgery. (3)Short-term is defined as within 30 days of surgery or the first discharge if the hospital stay is > 30 days.

(4)Long-term is defined as the period from 30 days or more after the operation or the period between first discharge (the hospital days after surgery >30 days) and 3 years after the operation.

1. The overall survival is calculated from the day of surgery until death or until the final follow-up date, whichever occurs first.
2. For survival cases, the end point is the last date that survival was confirmed. If loss to follow-up occurred, the end point is the final date that survival could be confirmed.

Definition of recurrence and recurrence date The following situations are regarded as "recurrence"

1. Recurrence identified by any one image examination (X-ray, ultrasound, computed tomography, magnetic resonance imaging, etc.) and, if there are a variety of imaging examinations, results without contradiction determined "recurrence". The earliest date that the recurrence is found is defined as the "recurrence date".
2. For cases that lack the use of imaging or a pathological diagnosis, the date of diagnosing the occurrence of clinical recurrence based on clinical history and physical examination is defined as the "recurrence date".
3. For cases without imaging or clinical diagnosis but with a cytology or tissue biopsy pathological diagnosis of recurrence, the earliest date confirmed by cytology or biopsy pathology is considered the "recurrence date".
4. A rise in carcinoembryonic antigen or other associated tumor markers alone could not be diagnosed as a relapse.

1. The number of all patients treated with surgery as the denominator and the number of the patients with any intraoperative and postoperative morbidity and mortality as the numerator are used to calculate the proportions.
2. Postoperative morbidities are divided into short-term and long-term complications after surgery.
3. Short-term is defined as within 30 days of surgery or the first discharge if the hospital stay is > 30 days.
4. Long-term is defined as the period from 30 days or more after the operation or the period between first discharge (the hospital days after surgery >30 days) and 3 years after the operation.
5. Postoperative mortality: patients whose death was identified according to documented intraoperative observation items, including patients who die within 30 days after surgery (including the 30th day) regardless of the causality between death and surgery, and patients who die more than 30 days after surgery.

Time to first ambulation in hours is used to assess the postoperative recovery course.

Time to first flatus in days is used to assess the postoperative recovery course.

Time to first liquid diet in days is used to assess the postoperative recovery course.

Time to first soft diet in days is used to assess the postoperative recovery course.

Duration of postoperative hospital stay in days is used to assess the postoperative recovery course.

Intraoperative tumor rupture rates are used to access the oncological safety of the intervention.

The variation of album in gram/liter on preoperative 7 days and postoperative 1 and 5 days are used to access the postoperative nutritional status and quality of life.

The variation of hemoglobin in gram/liter on preoperative 7 days and postoperative 1 and 5 days are used to access the postoperative nutritional status and quality of life.

The values of white blood cell count from peripheral blood preoperative 7 days and postoperative 1 and 5 days are recorded to access the inflammatory and immune response.

The values of C-reactive protein IN milligram/liter from peripheral blood preoperative 7 days and postoperative 1 and 5 days are recorded to access the inflammatory and immune response.