2.1. Clinical data
This research was approved by the ethics committee of the Nara Medical University, and all participants provided informed consent (reference ID: 1256 and 1719). The date of ethical approval was May 30th 2017, which is prior to the first surgery performed. We prospectively selected the patients and gave full information regarding the novel surgical method. All patients underwent dynamic computed tomography (CT) or CT urography before surgery to determine tumor location and size. The main exclusion criteria were 1) tumor of the distal ureter, 2) advanced tumor detected by CT (suspected T3/T4 disease or node-positive disease), 3) contraindications to laparoscopic surgery, or 4) concurrent bladder tumor.
We conducted a review of four patients with UTUC who underwent complete laparoscopic nephroureterectomy with transvesical laparoscopic bladder cuff excision between January 2018 and December 2019. All surgeries were performed by a single laparoscopically experienced surgeon (M. Miyake). Peri-operative complications were objectively evaluated using the Clavien-Dindo classification system [9]. This system includes seven grades (I, II, IIIa, IIIb, IVa, IVb, and V). The degree of postoperative pain was evaluated every day during hospitalization and on the first outpatient visit day using a numeric pain rating scale (NPRS), where 0 indicates no pain and 10 indicates the worst imaginable pain [10]. Four patients who underwent conventional retroperitoneal laparoscopic surgery combined with an open bladder cuff using a lower abdominal midline incision, by the same surgeon (M. Miyake), during the same period, were included as a control group for pain scale evaluation.
2.2. Surgical procedure for complete laparoscopic RNU
An operation video demonstrating the surgical procedures is given in Supplementary Video S1. A diagram of each step of the surgical procedure are depicted in Figure 1. Under general anesthesia, each patient was placed in a lateral decubitus position with the cancerous side up for a retroperitoneoscopic nephrectomy. The retroperitoneal cavity was dilated with a retroperitoneal balloon and maintained with 8 mmHg CO2 of insufflation pressure. We carried out conventional retroperitoneal approach with four ports as shown in Figure 2A: a flexible endoscope (camera) trocar, 12-mm trocar, 5-mm trocar, and auxiliary 5-mm trocar. The procedure includes the standard nephrectomy using laparoscopic monopolar scissors (e.g., AESCULAP® laparoscopic instruments), LigaSure™ Maryland jaw sealer (Covidien Japan, Tokyo, Japan), and Hem-o-lokÒ clips [11]. The renal artery was secured with a size L clip, followed by clamping of the ureter at the distal area with a size L clip or ML clip after stopping urine production in the kidney (Figure 2B). Then, the renal vein was secured with a size XL clip and the kidney was completely freed. The adrenal gland was retained in all cases.
A 5-mm trocar was added to the ipsilateral pelvic area to facilitate a wide operation space in the phase of dissection of the distal ureter (Figure 2A, red triangle). The ureter was dissected under the common iliac artery to the bladder. The distal ureter was dissected maximally and the urinary bladder remained unclosed during this phase (Figure 2C). During the retroperitoneoscopic procedure, the ureter was not cut and divided to enable complete en-block removal of the kidney and ureter.
Next, the patient was changed to the lithotomy position for transvesical laparoscopic bladder cuff excision. The operation was restarted with cystoscopy and performed according to the procedure reported by Yeung et al. [11]. The surgeon stands on the patient’s left side. Under cystoscopic guidance, three 5-mm trocars (Kii Advanced Fixation Sleeve; Applied Medical, Rancho Santa Margarita, CA, USA) were placed from the suprapubic region into the bladder (Figure 3A). Under 8 mmHg CO2 of pneumovesicum pressure, the ureterovesical junction and Waldeyer's sheath were excised with a 3-mm laparoscopic monopolar scissors until the paravesical adipose tissue was visible (Figure 3B-D). After completely mobilizing the ureter, the ureter was pushed back to the retroperitoneal space (Figure 3E). Then, the muscular defect and mucosal defect in the ureteral hiatus were sutured intravesically (Figure 3F, G). Intravesical trocars were removed under endoscopic vision without suturing the bladder wall. Each port site entry wound was closed with a 4-0 PDSII monocryl suture (Ethicon, NJ, USA).
In female patients, the specimen was extracted transvaginally in a bag (Figure 4A). In male patients, the specimen was extracted in a bag through a lower abdominal muscle splitting incision between the two auxiliary ports. A pelvic drain tube was placed through the pelvic auxiliary port.
2.3. Control group undergoing conventional RNU
Conventional surgery consists of laparoscopic nephrectomy with open bladder cuff excision. In the retroperitoneoscopic phase, the ureter was freed to the bifurcation level of iliac vessels along the level of the lower pole of the kidney. Next, the patient was placed in the supine position for open bladder cuff excision. An 8-10 cm midline incision was made on the lower abdomen. After extracting the kidney from the body, pulling the ureter exposed the bladder, thus facilitating excision of the bladder cuff. The remaining junction of the ureter and bladder was cut off, and the bladder wall was sutured with a 3-0 Vicryl suture. A pelvic drain tube was placed, and the incision was closed.
2.4. Follow-up after the RNU
A urinary catheter was left for approximately a week and removed after cystography. Cystoscopy and chest/abdomen/pelvis CT scans were performed approximately every 3 months for 2 years after the RNU, every 6 months from year 2 to 5, and annually thereafter.