The study is a retrospective cohort study and was conducted in accordance with the ethical principles set forth in the Declaration of Helsinki and the research protocol approved by the University Ethical Review Board (approval no. T2020-0070).
1. Cases and surgeons
Of the cases in which LM was performed at our hospital between January 2001 and December 2016, the currently performed GRP-LM was targeted. In all cases, the selection of eligible patients was based on preoperative MRI and ultrasonography before the surgery was planned. The surgeon was selected according to the difficulty of the operation, although the operation was performed by endoscopy-certified specialists, gynecologists and residents.
2. Techniques for securing the operative field in GRP-LM
An additional movie file shows this more detail [See Additional file 1].
2.1 Equipment required for SAWL
SAWL was performed using the instruments from Mizuho Medical Co., Ltd (Tokyo, Japan) shown in Fig. 1.
2.2 Lifting the abdominal wall
A Kirschner steel wire (1.2 mm diameter) was inserted onto the subcutaneous sagittal line in the midline of the abdominal wall. A Nelaton catheter was passed through a steel wire to prevent skin damage and fixed to the lifting handle (Fig. 2-A). The abdominal wall was lifted by using this as a support, and the chain was fixed to the lifting arm (Fig. 2-B).
2.3 How to make an abdominal port
A small incision was made in the right lower abdominal wall (Fig. 2-C). The fascia was clamped immediately below with Kocher forceps, and cut with scissors. Then the ventral fascia was bluntly punctured to reach the peritoneum (Fig. 2-D). After grasping the peritoneum at two places with Pean forceps (Fig. 2-E), a small incision was made with a scalpel to reach the abdominal cavity. The released peritoneum was grasped with four Pean forceps (Fig.2-F), and the Lap Protector® (Hakko, Chikuma, Nagano, Japan) was inserted (Fig.2-G, H). A 5 mm trocar was inserted from the umbilical fossa under supervision of the endoscope (Fig.2-I).
3. Surgical procedure in GRP-LM
3.1 Local injection of Vasopressin (Pitressin®)
Diluted Vasopressin (1 ml 20 units) was locally injected into the incision and surrounding muscle layers.
3.2 Incision of the uterine wall
The boundary between the myometrium and the fibroid became clear by making an incision up to the fibroid with a monopolar on the uterine serosa surface where the fibroid existed. If the size of fibroid was large, trimming the serosa of the uterus into an elliptical shape facilitated enucleation and subsequent suturing.
3.3 Removal of fibroids
When the fibroid was raised about 50%, the fibroid was grasped with Tenaculum Forceps. A suction tube or an electric scalpel through the Lap Protector was used to separate the pulled fibroid bluntly and sharply (Fig.3-A, B).
3.4 Suture and ligation
An additional movie file shows this more detail [See Additional file 2].
The suture of the muscle layer was performed with a single-knot suture using CONTROL RELEASETM synthetic absorbent threads (1-0 and 3-0) or large needles (needle length 48mm, suture size 1: Vicryl JB725®︎). The ligation was carried out by an instrumental knot, in which a knot was formed outside the body. Then, a thread was grasped and fed into the abdominal cavity for ligation (Fig. 3-C). When taking out the needle, the needle was not directly grasped, but the thread was grasped several cm away from the needle. This prevented the needle from slipping near the Lap Protector.
3.5 Removal of fibroids from the body
For fibroids that had enucleated, threads were sewn and used as support threads to avoid straying deep inside the body. Shredding was performed by grasping a fibroid with several Kochel forceps and using a sharp-edged scalpel to cut the fibroid into pieces, as if peeling an apple (Fig.3-D).
Currently, the excised fibroids were collected in a bag and then sectioned (Fig. 3-E).
3.6 Confirmation of hemostasis and use of anti-adhesion agent
After sufficient intraperitoneal lavage with 2000 to 3000 ml of physiological saline using the funnel (Fig. 3-F), hemostasis was confirmed.
3.7 For the use of the bag
The Rusch MemoBag® (Teleflex, Morrisville, NC) with inner diameter 100 mm was first inserted into the abdominal cavity, and then the fibroids detained by the thread were collected in the bag. After removing the Lap Protector, the mouth of the bag was guided outside the body, the Lap Protector was reattached, and hand morcellation of the fibroids was performed using a scalpel (Fig. 4).
4.1 The patient background, operative time, blood loss, uterine fibroid weight, number of fibroids, hospital stay, complications, transition rate to laparotomy, and pathological diagnosis in GRP-LM was compared our previous gasless laparoscopic myomectomy (G-LM).
4.2 The relationship between the number of uterine fibroids (1-10 or more) and operative time, blood loss, and fibroid weight in GRP-LM was investigated.
4.3 The preparation time from the start of the lifting procedures to the securing of the surgical field, as well as the number of sutures and the time per suture and ligation were examined by playing back the videos taken during the operation for 50 randomly selected cases. The size of the incision wound made in the lower abdomen was also measured postoperatively.
5. Statistical analysis
Student’s t test was used for comparison between two groups, and Chi-square test was used to analyze the association between the groups. The correlation between groups was performed using Pearson's product moment correlation coefficient. The difference was judged to be statistically significant when p < 0.05. Statistical analysis was performed using the Statistical Package for the Social Sciences version 26.