Upper urinary tract urothelial carcinoma (UTUC) is a malignant tumour of the urologic system with a relatively low incidence and poor prognosis. In terms of the surgical approach, open RNU with bladder cuff excision is the gold standard treatment. However, with the advancements of surgical instruments and the development of laparoscopic techniques, laparoscopic RNU, as a more minimally invasive surgical approach, is gradually becoming mainstream for UTUC in experienced hands and can acquire similar oncological outcomes compared with open surgery[3, 4].
The traditional laparoscopic approach is performed with at least three tracar incisions and one large incision and. Many surgeons hesitate to use laparoscopic procedures for the distal ureter because the pelvic ureterovesical junction is deep, which subsequently converts to open bladder cuff excision with at least an 8 cm incision. Therefore, the traditional laparoscopic approach still causes significant surgical trauma,. To pursue more minimally invasive surgery, these procedures can be achieved with one incision just for removing specimens when pure LSRNU emerges.
What the essential procedure of RNU is the management of bladder cuff. As we all know, several techniques have been deemed to simplify the resection of distal ureter, including the pluck technique, intussusception, stripping, and transurethral resection of the intramural ureter. Although each technique has its strengths and weaknesses, till now none of these techniques has convincingly been displayed to be equal to complete bladder cuff excision[6, 14]. Additionally, the extravesical stapling technique is a pure laparoscopic approach, which has shorter operative time and keeps the urinary system closed to avoid tumor spread. Meanwhile, some literatures had shown higher incidences of positive surgical margins and local recurrence compared to other techniques of bladder cuff excision[15, 16]. Therefore, it is necessary optimize this pure laparoscopic technique to reduce surgical trauma and improve oncological outcomes.
Our technique is an innovative modification of pure LSRNU that highlights its advantages. First, the custom-made laparoscopic bulldog clamp helps the surgeon finish the en bloc removal of the complete distal ureter and bladder cuff, similar to the open technique, without opening the urinary tract to prevent tumor spillage. This conforms to the oncological principle because enough bladder cuff is guaranteed by the approach. Second, by adding a trocar at the midline of the lower abdomen, surgeons are able to gain enough vision and perform precise bladder cuff excision with the patient remaining in the same position. The bulldog clamp accompanied by suturing rather than Endo-GIA with staples could prevent bladder stones from happening to a certain extent. Finally, this technique is not only a more minimally invasive incision in the lower abdomen but also avoids unnecessary operations and in theory reduces the risk of infection without changing the position, disinfection or drape once again.
Several studies have demonstrated that a single dose of intravesical chemotherapy 2–10 days after surgery reduces bladder tumor recurrence. Therefore, a single dose of intravesical chemotherapy was performed postoperatively. For the oncological outcomes, the Kaplan–Meier analyses showed that the 5-year OS and CSS of pure transperitoneal LSRNU were 78.9% and 81.4%, respectively. This study has relatively better outcomes than some traditional LSRUNs[18, 19]. It has been reported that recurrence in the bladder occurs in 22–47% of UTUC patients, compared with 2–6% in the contralateral upper tract. Recurrence in the bladder was 16.0%, compared with 4.6% in the contralateral upper tract in our study. Therefore, excellent oncological outcomes are displayed by our techniques. This is the largest and longest follow-up study among pure LSRNU without patient repositioning for UTUC.
In addition, several authors have described pure robot-assisted RNU with good clinical outcomes. If our technique could be adopted in robot-assisted surgery, it might decrease the difficulty of intracorporeal suturing. However, a high cost restricts the availability of robots in China.
There were several limitations in our study. First, the retrospective study was performed in a single medical center in China, which may cause a potential selection bias. A larger number of series and more extended follow-up periods are needed to confirm these results and achieve further evidence about the clinical effect of pure transperitoneal LSRNU for UTUC. We are optimistic that this initial report can serve as a foundation for developing optimal treatment for UTUC.