Robot-assisted partial nephrectomy for large complex renal cancer: step-by-step segmental artery unclamping

ABSTRACT

Introduction

Main renal artery clamping and selective arterial clamping are two conventional devascularization methods for robot-assisted partial nephrectomy (RAPN) (¹, ²). Decreasing warm ischemic (WI) time (³, ⁴) and improving clear surgical visualization (⁵) are the main surgically modifiable factors for RAPN, especially in large complex renal cancer (⁶). In this study, we described our surgical technique, focusing on gradual segmental artery unclamping on patients with large renal tumors.

Material and methods

Two patients (R.E.N.A.L score 10 and 11) underwent RAPN with gradual segmental artery unclamping (Figures 1 and 2). The unclamping included five key steps. First, all renal segmental arteries were identified as tumor feeding vessel(s) and the vessels for normal kidney parenchyma under the guidance of CT angiography (CTA) 3-division (3D) reconstruction. Second, all segmental arteries were isolated, and the feeding one(s) should be blocked before other arteries were blocked. Third, the tumor was resected outside the pseudocapsule, and the deep resection bed was sutured for initial hemostasis. Fourth, the segmental arteries were reopened except for the tumor feeding one(s), and normal kidney parenchyma restored blood supply. And fifth, the resection bed was completely sutured, and the feeding vessel supplying the tumor was opened after the suture. Warm ischemia time (WIT) was defined as the time measured between clamping and unclamping of the renal artery. WIT1 was the time for normal kidney parenchyma and WIT2 was the time for resection area. Patient demographics, perioperative variables, and warm ischemic time were included in our study. And we presented the details of gradual segmental artery unclamping in the video.

Results

In both cases, the total operation times were 215 and 130 mins for patient 1 and patient 2, respectively. WIT1 and WIT2 for patient 1 were 15 min and 33 min., and WIT1 and WIT2 for patient 2 were 21 min and 32 min, respectivelly. The maximum diameters of the masses resected were 10.8 and 7.3 cm, and surgical margins were negative. No patient had complications after operation. Preoperative and postoperative eGFR did not change significantly. Pre- and postoperative eGFR were 111 and 108 mL/min for patient 1, 91 and 83 mL/min for patient 2, respectively. Key hints for outcomes optimization during RAPN on patients with large complex renal tumors: 1) Each segmental renal artery is precised clamped before we excise the tumor, and an excellent surgical vision is essential for precising excision and shortening clamping time, 2) Other segmental renal arteries are unclamped except tumor feeding branch after suturing deep layer of parenchyma, and most normal parenchyma restores blood supply, 3) Preoperative high-resolution computed tomography angiography (CTA) and 3D reconstructive renal structure serve as a guide to clear the approach to find the tumor and segmental arteries (⁷, ⁸).

Conclusions

Gradual segmental artery unclamping is feasible and efficient to excise large complex renal cancer. Compared with main renal artery clamping, it can shorten the warm ischemic time of normal parenchyma; On the other hand, compared with selective segmental arterial clamping, the technique can reduce bleeding from the deep resection bed, keep a clear surgical vision, and decrease the incidence of positive margin.

ACKNOWLEDGEMENTS

Yong Huang, Junjie Cen, Yiming Tang contributed equally to this work.

REFERENCES

• ¹
  Desai MM, de Castro Abreu AL, Leslie S, Cai J, Huang EY, Lewandowski PM, et al. Robotic partial nephrectomy with superselective versus main artery clamping: a retrospective comparison. Eur Urol. 2014;66:713-9.
• ²
  Deng H, Fan Y, Yuan F, Wang L, Hong Z, Zhan J, et al. Partial nephrectomy provides equivalent oncologic outcomes and better renal function preservation than radical nephrectomy for pathological T3a renal cell carcinoma: A meta-analysis. Int Braz J Urol. 2021;47:46-60.
• ³
  Bai N, Qi M, Shan D, Liu S, Na T, Chen L. Trifecta achievement in patients undergoing partial nephrectomy: a systematic review and meta-analysis of predictive factors. Int Braz J Urol. 2022;48:625-36.
• ⁴
  Shao P, Tang L, Li P, Xu Y, Qin C, Cao Q, et al. Precise segmental renal artery clamping under the guidance of dual-source computed tomography angiography during laparoscopic partial nephrectomy. Eur Urol. 2012;62:1001-8.
• ⁵
  Furukawa J, Miyake H, Hinata N, Muramaki M, Tanaka K, Fujisawa M. Renal Functional and Perioperative Outcomes of Selective Versus Complete Renal Arterial Clamping During Robot-Assisted Partial Nephrectomy: Early Single-Center Experience With 39 Cases. Surg Innov. 2016;23:242-8.
• ⁶
  Dos Reis RB, Feres RN, da Silva MC, Muglia VF, Rodrigues AA Júnior. The dilemma of partial nephrectomy and surgical upstaging. Int Braz J Urol. 2022;48:795-7.
• ⁷
  Grosso AA, Di Maida F, Tellini R, Mari A, Sforza S, Masieri L, et al. Robot-assisted partial nephrectomy with 3D preoperative surgical planning: video presentation of the florentine experience. Int Braz J Urol. 2021;47:1272-3.
• ⁸
  Hekman MCH, Rijpkema M, Langenhuijsen JF, Boerman OC, Oosterwijk E, Mulders PFA. Intraoperative Imaging Techniques to Support Complete Tumor Resection in Partial Nephrectomy. Eur Urol Focus. 2018;4:960-8.

• Available at: http://www.intbrazjurol.com.br/video-section/20220572_Luo_et_al

Publication Dates

• Publication in this collection
  05 June 2023
• Date of issue
  May-Jun 2023

History

• Received
  16 Nov 2022
• Accepted
  05 Dec 2022
• Published
  18 Dec 2022