Partial nephrectomy is the treatment of preferred choice for T1 renal cell carcinoma as it preserves kidney function better and potentially limits the incidence of cardiovascular disordersin the long term [3]. Surgical methods for partial nephrectomy include open, pure laparoscopic, and robotic-assisted surgery [6]. Zhao et al. [7] reported that open partial nephrectomy and LPN have the same tumor control and renal function protection effects. Moreover, LPN has the advantages of less bleeding, less pain, faster postoperative recovery, and improved aesthetics [8]. The development of technology and greater surgical experience has led to a wider use of robotic surgery, especially for some complex renal tumors [9, 10]. However, in different countries and different regions of the same country, economic development and access to these resources is unbalanced. Robotic systems are only used at some larger medical centers and have not yet been sufficiently popularized in China or other developing countries. According to the data reported by Da Vinci Corp, by the end of 2021, 6,730 units were installed globally and 260 units were installed in China (3.86%). However, there are 3,275 tertiary hospitals in China, and only 215 units have robotic systems (6.57%). Boga et al. [11] demonstrated comparable perioperative and long-term tumor and functional outcomes in laparoscopic and robotic-assisted laparoscopic partial nephrectomy. Moreover, laparoscopic surgery is more cost-effective [12]. Therefore, compared with robotic surgery, laparoscopic surgery is still the most mainstream option in China or other developing countries[13].
There are two approaches of LPN: retroperitoneal and transperitoneal. Takagi et al. [14] concluded that compared with the transperitoneal approach, the retroperitoneal approach exposes renal arteries more fully, and has the advantages of a shorter operative time, warm ischemia time period, and shorter hospital stay. Nikolaos et al. [15] concluded that both transperitoneal and retroperitoneal partial nephrectomy are safe and effective methods; however, the retroperitoneal approach avoids the influence of intestinal canal and extensive kidney dissociation, more easily exposes the renal artery, and requires less time. Kobari et al. [16] shared the same view and suggest the retroperitoneal approach. The retroperitoneal approach was also chosen for this study.
The surgical methods can be categorized according to the number of puncture holes: Three-hole method, four-hole method, and porous method. The four-hole method has one more trocar (5 mm) than the three-hole method, resulting in few additional effects on the esthetics and postoperative recovery. An assistant channel was added to make the surgical area easier to expose and facilitate the procedure. However, the assistant channel was previously located at the intersection of the anterior axillary line and the level of the umbilicus[17]. This small space can affect the effective cooperation between the surgeon and assistant.
We adjusted the assistant channel below the 11th costal margin of the midaxillary line and achieved good results. Our studies have shown that the operative time, warm ischemia time, and blood loss are superior to those of the trapezoidal layout method (p < 0.05). Although the effect of postoperative renal function is not statistically significant, it has some advantages. The advantages of the umbrella-shaped layout are as follows: The assistant channel is relatively close to the target; shuttle in and out of surgical field with instruments are operated under the direct view of the lens, which can quickly and accurately reach the operating area; the assistant channel is far from the operation channel and observation channel, thus avoiding interaction with the lens and operator; greater convenience for the operator, which speeds the operation process; the assistant channel is far from the peritoneum, thus avoiding the possibility of secondary injury during puncture and surgery; there is only one operator at the back of the patient, which is convenient for the operation; the assistant and the mirror supporter are located on the ventral side and their positions do not overlap; and the standing position is reasonable.