Study design
TLU and VNE techniques have been implemented in the Obstetrics and Gynecology Department of Balıkesir University since 2018, and patients’ medical files were retrospectively reviewed between 2019 and 2022. Patients whose body mass index (BMI) was between 20–40 and who underwent laparoscopic surgery, whether the TLU or VNE technique, for gynecologic diseases and malignancies were included in the study. The indications for gynecological operations are as follows: myoma uteri, adenomyosis, endometrial hyperplasia with atypia, suspicious adnexal masses, endometrioma and endometriosis, stress urinary incontinence, and pelvic organ prolapse. On the other hand, the indications for oncological surgeries are endometrial cancer and borderline ovarian tumors.
Patients were randomly allocated to the TLU or VNE groups. However, patients with a history of surgery with a midline incision, umbilical hernias, mesh placement to the umbilicus, massive ascites, or liver diseases were excluded from the study. Each group contained 36 patients tiered according to their BMI, such as BMIs between 20–25 (normal weight), 25–30 (overweight), 30–35 (class I obesity), and 35–40 (class II obesity), and equally distributed based on each BMI tier so that all subgroups contained nine patients.
Patients underwent elective gynecologic or oncologic operations requiring endotracheal intubation under general anesthesia at the dorsal lithotomy position. These operations were performed by three experienced surgeons at Balikesir University Hospital. Anticoagulation was discontinued at least 24 hours before surgery, and 2 g of cefazolin was administered before the skin incision for antimicrobial prophylaxis. Gastric decompression was provided with an orogastric tube before the skin incision. The umbilicus was cleansed with povidone-iodine, and lint was mechanically removed if present.
Patients’ demographic and anthropometric parameters were recorded. Their past and current surgical procedures and menopausal status were documented. Both laparoscopic access techniques were compared according to the entry time, vascular or visceral injuries, insufflation failures, trocar-related complications, and omental injury. The duration of laparoscopic access was defined as the period between the incision and the visualization of the abdominal cavity determined using a cell phone chronometer. If the surgeon made more than two attempts with a Veress needle, it was considered a failed insufflation. The primary outcome of this study was the entry time. Secondary outcomes were vascular or visceral injuries, insufflation failures, and trocar-related complications.
The definition of surgical techniques
TLU technique
After a 12 mm vertical skin incision was made to the upper border of the UR, the subcutaneous fat was dissected with a pean clamp until the ligamentum teres, also known as the ligamentum rotundum, was visualized or palpated with an index finger. Then, the caudal part of the teres ligament, which is joined to the umbilical ring, was elevated with the help of a straight Kocher clamp. Afterward, a Farabeuf retractor was placed on one side of the teres ligament, and the cranial part of the teres ligament was elevated with the help of a curved Kocher clamp, which was placed 1 cm above the first clamp. Finally, an 11 mm incision that gives a 30 to 45-degree angle to the teres ligament was made between the Kocher clamps. A central 11-mm trocar was inserted into the abdominal cavity without an inner tube through the incision, and the abdominal organs were visualized (Supplementary video).
VNE technique
Following the elevation of the umbilicus with two towel clips placed on the lateral border of the UR, a single-use Veress needle was vertically inserted into the lowest point of the umbilicus without using a scalpel. Laparoscopic entry into the abdominal cavity was confirmed by a double-pop test, saline drop test, and verification of intra-abdominal pressure (< 10 mmHg) (11). After the intra-abdominal pressure reached 20 mmHg, a supraumbilical 12 mm slightly concave horizontal skin incision was made. The central trocar was placed into the abdominal cavity, and the abdominal organs were visualized.
Statistics
The study's statistical analysis and power analysis were performed with open-source Jamovi statistical software (version 2.3.21) and G* Power software (version 3.1.9.7). The minimum sample size was calculated as 36 per group based on α error: 0.001, power: 0.95, and effect size d:1 according to the literature. The distribution and homogeneity of groups were evaluated by skewness, kurtosis, Levene’s test, and Kolmogorov-Smirnov test. Independent-sample Student’s t-test was used to compare the group variables. After log10 conversion of variances, subgroup analysis was conducted using one-way ANOVA and Tukey’s post hoc test.