Robotic salvage retroperitoneal and pelvic lymph node dissection for 'node-only' recurrent prostate cancer: technique and initial series

Abstract

Objectives: To describe the technique of robot-assisted high-extended salvage retroperitoneal and pelvic lymphadenectomy (sRPLND+PLND) for 'node-only' recurrent prostate cancer.

Patients and methods: In all, 10 patients underwent robot-assisted sRPLND+PLND (09/2015-03/2016) for 'node-only' recurrent prostate cancer, as identified by ¹¹ C-acetate positron emission tomography/computed tomography imaging. Our anatomical template extends from bilateral renal artery/vein cranially up to Cloquet's node caudally, completely excising lymphatic-fatty tissue from aorto-caval and iliac vascular trees; RPLND precedes PLND. Meticulous node-mapping assessed nodes at four prospectively assigned anatomical zones.

Results: The median operative time was 4.8 h, estimated blood loss 100 mL and hospital stay 1 day. No patient had an intraoperative complication, open conversion or blood transfusion. Three patients had spontaneously resolving Clavien-Dindo grade II postoperative complications. The mean (range) number of nodes excised per patient was 83 (41-132) and mean (range) number of positive nodes per patient was 23 (0-109). Seven patients (70%) had positive nodes on final pathology. Node-positive rates per anatomical level I, II, III and IV were 28%, 32%, 33% and 33%, respectively. In patients with positive nodes, the median PSA level had decreased by 83% at the 2-month follow-up.

Conclusion: The initial series of robot-assisted sRPLND+PLND is presented, wherein we duplicate open surgery with superior nodal counts and decreased morbidity. Robot-assisted technical details for an anatomical LND template up to the renal vessels are presented. Longer follow-up is necessary to assess oncological outcomes.

Keywords: #PCSM; #ProstateCancer; robot-assisted surgery; salvage PLND; salvage RPLND.

Fig. 1

¹¹C-acetate PET/CT imaging. PET/CT showing a 1.3-cm ¹¹C-acetate avid left common iliac lymph node. ¹¹C-acetate PET/CT imaging was performed on an integrated PET/CT scanner (Siemens Biograph 16; Malvern, PA, USA). Patients were positioned on the camera and then 740–1 480 MBq ¹¹C-acetate (half-life 20.3 min) was administered as a bolus i.v. injection. A CT topogram was obtained from the vertex through the pelvis. Based on the topogram, the tube current for the CT scan was adjusted using a Care doseTM application to minimise exposure. The tube voltage was 130 kVp (peak kilovoltage). After the CT scan, emission images beginning at the pelvis and proceeding cranially were obtained (3–7 min after injection, mean 4.25 min). Images were reconstructed with iterative reconstruction (two iterations, eight subsets, matrix 168, Gaussian filter). The administration of ¹¹C-acetate was well tolerated by all patients and there were no adverse events. All images were interpreted by nuclear medicine physicians with >20 years of PET imaging experience.

Fig. 2

Port placement. A six-port transperitoneal approach is used: the camera port (blue circle) is placed 6–8 cm above the umbilicus, the robotic ports (black circles) are placed at the level of the 12th rib, and a 15-mm assistant port (red circle) is placed at the umbilicus level. A 12-mm AirSeal® port (green circle) is placed proximal and lateral to the camera port.

Fig. 3

Intraoperative pictures of sRPLND/PLND. (A) Level IV – RPLND: The lower edge of the right renal artery (RRA) and left renal vein (LRV) are skeletonised, establishing the cranial boundary of the dissection. The IVC and aorta (Ao) are vessel-looped and elevated anteriorly to excise retro-caval and retro-aortic tissues, exposing the anterior spinous ligament (*) at the inter-aorto-caval area. (B) Level III – RPLND: The IMA is skeletonised; infra-IMA dissection is performed towards the Ao bifurcation (Ao-Bi) and the proximal parts of the right (RCI) and left (LCI) common iliac arteries are dissected. (C) Level II – RPLND/PLND: Bilateral extended PLND comprises pre-sacral (PSc), para-rectal (PR), and the RCI and LCI arteries. The right ureter (RU) is vessel-looped, the sigmoid colon (SC) is retracted laterally. REI, right external iliac artery. (D) Level I – right PLND: The REI and vein are skeletonised and retracted medially with the RU to expose the pre-sciatic (PSi) area. The obturator fossa (OF) is completely dissected exposing the obturator nerve (arrow). The right genito-femoral nerve (RGFN) is the lateral limit of dissection. (E) Level I – left PLND: With the SC and the left ureter retracted medially, the distal part of the LCI and the proximal part of the left external iliac artery (LEI) and vein (LEIV), and the left internal iliac artery (LII) are skeletonised. (F) Level I – left PLND: The left LEI and LEIV are skeletonised and retracted medially allowing dissection of the left pre-sciatic (‘fossa of Marseilles’) area and OF, exposing the left obturator nerve (LON).

Fig. 4

sRPLND/PLND template. We categorised the sRPLND/PLND template into four anatomical levels, as follows: Level I: Cephalad extent: internal iliac artery. Caudal limit: lymph node of Cloquet. Lateral limit: genito-femoral nerve. Posterior limit: Pre-rectal nodes and nodes posterior to the obturator nerve. Level I template includes nodes in the regions of the internal and external iliac vessels, obturator fossa, pre-sciatic fossa of Marseilles and pre-rectal nodes. Level II: Cephalad extent: aortic bifurcation. This region includes nodes in the regions of the common iliac vein and artery, upper pre-sciatic nodes, pre-sacral nodes and nodes in the region of the aortic bifurcation. Level III: Cephalad extent: inferior mesenteric artery (IMA). This region includes the distal para-caval, pre-caval, retro-caval, inter-aorto-caval, pre-aortic, retro-aortic and para-aortic nodes up to and including the IMA. Lateral limit: bilateral ureters. Level IV: Cephalad extent: left renal vein and the right renal artery along the undersurface of the third part of duodenum. This region includes nodes in the proximal para-caval, pre-caval, retro-caval, inter-aorto-caval, pre-aortic, retro-aortic and para-aortic tissue cephalad to the IMA. Lateral limit: bilateral ureters. This figure shows node-mapping from the patient shown in Fig. 1. The patient was a 76-year-old man with Gleason 8 (4 + 4) prostate cancer treated primarily with RT. His PSA level before sRPLND+PLND was 7.58 ng/mL. Of 132 nodes extracted, 65 were positive. At the 2-month postoperative follow-up his PSA level was 0.4 ng/mL. Green circle represents the positive node on preoperative PET-CT that was confirmed as node metastasis on final pathology.