2.1 Ethical approval
Written informed consent was obtained from all patients. In addition, approval was obtained from the Ethics Committee of the Nippon Medical School Chiba Hokusoh Hospital (approval number: 893).
2.2 Patient history
From April 2019 to December 2020, 48 patients who underwent surgery including lymphadenectomy for the diagnosis of cervical cancer or endometrial cancer were retrospectively examined. The classification of the cases was cervical cancer in 24 cases and endometrial cancer in 24 cases. 12 patients underwent only pelvic lymphadenectomy, 12 patients underwent pelvic lymphadenectomy and para-aortic lymphadenectomy, and 24 patients underwent radical hysterectomy and pelvic lymphadenectomy.
2.3 Study design
We retrospectively examined 48 patients with cervical cancer and endometrial cancer who were treated at the Nippon Medical School Chiba Hokuso Hospital from April 2019 to December 2020. Patients were divided into two groups: those who used absorbent threads for intraoperative lymphatic and vascular ligation (thread group) and those who used clips (clip group). Table 1 summarizes the age, BMI, surgery time and blood loss of all patients. Regarding the occurrence of lymphedema, only those in the early postoperative period (1 month after the operation) were analyzed. Lymphedemas were diagnosed by the nurse or the doctor who received special education on lymphedema. Below, the group of patients with endometrial cancer who underwent total hysterectomy + bilateral salpingo-oophorectomy + pelvic lymphadenectomy is defined as the PLN group. The group of patients who underwent total hysterectomy + bilateral salpingo-oophorectomy + pelvic lymphadenectomy + para-aortic lymphadenectomy is referred to as the PLN + PAN group, and the group of patients who underwent radical hysterectomy + pelvic lymphadenectomy for cervical cancer is referred to as the RH + PLN group.
2.4 Statistical analysis
Continuous variables are shown as means and standard deviations; these data were compared using Student t test or the Mann-Whitney U test. The Fisher's exact test was used to analyze the occurrence of postoperative recurrence and intraoperative complications associated with the clips.
All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), which is a graphical user interface for R (The R Foundation for Statistical Computing, Vienna, Austria). More precisely, it is a modified version of the R commander, which is designed to add statistical functions that are frequently used in biostatistics 17. All tests were 2-tailed, and the threshold for significance was P < .05.
2.5 Surgical procedure
The extent of lymphadenectomy in endometrial cancer cases was determined using the method of Imai et al 18. That is, patients with score 0 are not administered lymphadenectomy, patients with score 1-2 are administered only pelvic lymphadenectomy, and patients with score 3-4 is pelvic lymphadenectomy and para-aortic lymphadenectomy. All patients with cervical cancer underwent nerve-conserving radical hysterectomy with pelvic lymphadenectomy (type C1 radical hysterectomy) 19. Pelvic and para-aortic lymph nodes were removed as en bloc as possible. The cranial and foot ends of the lymph vessels were ligated with absorbent threads or clips to prevent postoperative complications of lymphatic leakage and lymphocele.
2.6 Surgical instruments
In the thread group, 2-0 COATED VICRYL PLUS VIOLET 12X18 "TIE (Ethicon, Inc. Somerville, New Jersey, USA) was used for ligation. In the clip group, LIGACLIP® EXTRA Ligating Clips (Ethicon, Inc. Somerville, New Jersey, USA) was used in 15 cases, and Premium Surgiclip ™ II Clip Applier (Covidien, Dublin, Ireland) was used in 9 cases. For intraoperative vascular and lymphatic vessel amputations, the vascular sealing system LigaSureTM Maryland 23 NC (Medtronic plc, Dublin, Ireland) was used.