Introduction: Nephroureterectomy in a horseshoe kidney is challenging due to its malrotation, anomalous vasculature, and difficulty in mobilizing the fused renal moieties. In precisely separating the right and left renal moieties, hemostasis is dependent on controlling the vascular supply to the isthmus. We present a technique for robot-assisted laparoscopic (RAL) left nephroureterectomy in a 74-year-old male with left multifocal high grade upper tract urothelial carcinoma (HG UTUC) in a horseshoe kidney. Indocyanine green (ICG) and near-infrared fluorescence (NIRF) imaging (FireFly™, Intuitive Surgical, Inc.) was utilized to define the aberrant renal vasculature and aid in precise division of the isthmus for maximal parenchymal preservation.
Methods: A transperitoneal approach was used. After mobilizing the colon, optional use of intraoperative ultrasound can assist in localizing the renal hilar vessels and isthmus below the investing tissues. Further dissection revealed the anterior location of the renal pelvis, proximal ureter, and anomalous vascular anatomy. The gonadal vein, main, and accessory renal vessels were ligated and transected individually. The adrenal was left in situ. The lower pole of the left renal moiety was exposed, and the isthmus was identified. Intravenous injection of ICG and use of NIRF revealed fluorescence in the vascularized parenchyma of the right moiety, and absence of fluorescence in the ischemic left moiety. NIRF confirmed the absence of additional anomalous renal vessels and clearly delineated the plane between vascularized and devascularized tissue in the isthmus. The isthmus was sharply transected with robotic scissors, and the vascularized parenchyma was oversewn. The distal ureterectomy, bladder cuff excision, and cystorrhaphy were then completed.
Results: Operative time was 2 h 48 min with an estimated blood loss of 70 cc. The patient was discharged on the first postoperative day. The urethral catheter was removed after 6 days. Pathology revealed extensive pTa HG UTUC of the left renal pelvis and negative surgical margins. At 12 month follow up, the patient remains disease free. Preoperative creatinine and eGFR were 0.93 mg/dL and 81 mL/min/1.73m2, and 12-month postoperative values were 1.27 mg/dL and 55 mL/min/1.73m2.
Conclusions: RAL nephroureterectomy in a horseshoe kidney can be facilitated with judicious use of ICG and NIRF to aid in delineation of renal vasculature, confirmation of renal moiety devascularization, and in precise transection of the isthmus.