Extraperitoneal single-site robot-assisted radical prostatectomy with extended pelvic lymph node dissection: technique and experience

Abstract

For patients with locally advanced or high-risk localised prostate cancer who require lymph node dissection (LND), guidelines recommend an extended pelvic LND (ePLND). Such an extensive dissection ensures accurate staging information for most patients [1]. Advancements in surgical instrumentation and optimisation of surgical techniques could potentially empower surgeons to perform an ePLND in a more minimally invasive manner.

Extraperitoneal single-site or single-port robot-assisted radical prostatectomy (ESSRARP) has emerged as an intriguing concept. However, data from SSRARP with PLND studies have presented a less promising picture. The median number of lymph nodes (LNs) removed using the ESSRARP approach was only five [2, 3]. Compared with the transperitoneal anterior approach, the main difficulties for ePLND through an extraperitoneal approach are restricted workspace and a high incidence of symptomatic lymphocele [4, 5]. Exploring bridge technique is particularly interesting and appears to serve as good training for transitioning to the use of the single-port platform. Our primary aim in this study was to describe the surgical steps and technique of the ESSRARP with ePLND, along with the preliminary data.

Between June 2023 and December 2023, 31 patients underwent ESSRARP and ePLND (Table S1). The participants had a median age of 69 years and a median body mass index (BMI) of 21.71 kg/m². The median (IQR) PSA level at biopsy was 32.10 (16.7–51.0) ng/mL. Overall, five (16.13%), and 26 (83.78%) patients had pathological Gleason score of 7, and 8–10, respectively. Five patients (16.13%) had LN metastasis detected by ¹⁸F-prostate-specific membrane antigen positron emission tomography (PSMA PET)-CT.

The median (IQR) surgery duration and console time were 210 (185–226) min and 150 (136–170) min, respectively (Table S2). The median (IQR) estimated blood loss was 50 (40–50) mL. The (IQR) median number of LNs removed was 23 (18–29). Pathological LNI was diagnosed in seven patients (22.58%). Positive surgical margins were found in six (19.35%) patients.

Postoperative complications occurred in two patients (6.45%) (Table S3). One patient developed deep vein thrombosis requiring readmission, while the other developed acute epididymitis on postoperative Day 3, necessitating prolonged antibiotic therapy. No symptomatic lymphocele formation was observed (Table S3).

Our technique offers a valuable and timely alternative for urologists who lack access to dedicated single-port surgical systems. Our study achieved a median LN yield of 23, demonstrating a substantial improvement compared to prior research. It typically takes ~10 cases to complete the learning curve.

From the surgical technique standpoint, our approach maintained a distance between the camera and the surgical field, adjusting focus to maintain clarity. The shortened working arms of the robotic arms, while preserving their triangulated position, granted them wrist-like flexibility. The assistant employed the aspirator to retract the peritoneum and manage tissue tension. These refinements enabled us to achieve a more comprehensive dissection. Neoadjuvant hormonal therapy was administered to 15 patients, which may have resulted in reduced tumour burden and decreased LN volume near vessels. This simplified the surgery and likely improved safety.

The patients’ median BMI was 21.71 kg/m², but this does not limit the technique's applicability to a broader BMI range. We could reach all the extraperitoneal surgical field from the urethrovesical anastomosis up to the bifurcation of the aorta. For patients with a high BMI or high bifurcation of the common iliac vessels, we could reposition the port and re-dock the surgical arms towards to the pelvic LN region unilaterally (Fig. 3A,B).

Significantly, the extraperitoneal approach is associated with a higher prevalence of lymphocele [5]. Dal Moro and Zattoni [7] introduced the ‘preventing lymphocele ensuring absorption transperitoneally’ (P.L.E.A.T.) technique. By partial technical refinements, we performed the technique through the ESS approach. This innovation allowed for transperitoneal reabsorption of lymphatic fluid. None of our patients developed symptomatic lymphocele during short-term follow-up.

Postoperative pathology revealed that three patients, who had been staged as clinical N0, were found to have pathological N1 disease in our cohort. Nonetheless, the oncological benefit of ePLND is still debated, and evidence supporting LND for improved outcomes is limited especially given the increasing efficacy of PSMA PET-CT.

An ESSRARP with ePLND is a safe and effective treatment offering excellent short-term outcomes. Our approach is valuable for urologists without access to a dedicated single-port platforms.

This study was supported by Guangzhou Clinical Characteristic Technology Project: No.2023C-TS36 and the Guangdong Province High level Talents Special Support Program for Young Outstanding Talents: No.0720240251.

The authors declare that they have no competing interests. The research did not receive any funding from commercial sources. The authors have no financial or other relationships with any manufacturers of the devices or drugs used in this study. The authors’ institution has not received any commercial benefits from the publication of this study.

Di Gu and Yubo Wang had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Conceptualization and Methodology: Di Gu, Yubo Wang, Mingzhao Li, Shancheng Ren. Investigation: Yubo Wang. Formal analysis and Data Curation: Yubo Wang. Writing – Original Draft: Yubo Wang, Zhuyinjun Zong. Writing – Review and Editing: Di Gu, Kai Yao, Shancheng Ren, Mingzhao Li, Chao Cai. Visualization:Zhuyinjun Zong, Yubo Wang. Resources, Supervision, Project administration: Guohua Zeng, Di Gu, Kai Yao.