Indocyanine Green Fluorescence-Guided Laparoscopic Lower-Pole Heminephrectomy for Duplex Kidney in Adult

Abstract

Background: Intraoperative indocyanine green (ICG) near-infrared fluorescence guidance is a type of optical imaging technology now available to facilitate a better understanding of surgical landmarks. This case describes use of this technique during lower-pole heminephrectomy for a patient with duplex kidney.

Case Presentation: A 50-year-old woman with a left duplex system and lower-pole kidney infection underwent a laparoscopic transperitoneal lower-pole heminephrectomy. After exposing the left renal pedicles, ICG was administered through a ureteral stent inserted into the upper calix; the nonaffected ureter could be viewed, which enabled us to dissect the affected ureter connected to the lower-pole pelvis. Next, intravenous ICG administration revealed that the lower-pole kidney blood flow was not reduced. This finding prompted us to clamp the main renal artery. Furthermore, ICG injection through a nephrostomy tube helped to observe the lower-pole kidney collecting system and predict the parenchymal dissection plane location between the upper- and lower-pole kidneys. We effectively performed a lower-pole heminephrectomy through complete lower-pole urinary tract resection and maximal upper-pole parenchyma preservation.

Conclusion: ICG fluorescence by intravenous and intraureteral administration observes relevant anatomy intraoperatively and is beneficial in patients who undergo a lower-pole heminephrectomy for duplex kidney.

Introduction

Patients with duplex kidney can have complications such as obstructive or reflux nephropathy that can result in nonfunctioning kidneys. Heminephrectomy for the part of the affected kidney and duplicated ureter is usually offered to these patients to prevent recurrent urinary tract infections. However, the dissection plane between the nonfunctioning and a normal kidney may not be well defined, as the renal vasculature and the urinary system are anatomically complex. Therefore, a good preoperative understanding of the duplex kidney anatomical structure based on radiologic imaging as well as functional intraoperative observation can contribute to a safe operation. In this respect, intraoperative indocyanine green (ICG) near-infrared fluorescence guidance is expected to improve surgical quality. However, studies that used ICG for duplex kidney surgery, particularly heminephrectomy, for lower-pole duplex kidney, are limited. Herein, we described a case in which intravenous and intraureteral ICG was used to facilitate a laparoscopic lower-pole heminephrectomy in an adult patient with duplex kidney.

Presentation of Case

A 50-year-old woman presented with fever and left back pain. Nonenhanced CT revealed a left duplex kidney with hydronephrosis and thinned lower-pole kidney parenchyma (Fig. 1). Inflammatory changes were observed around the lower pole, resulting in the diagnosis of lower pole-obstructed pyelonephritis. Retrograde pyelography revealed that the ureter from the upper and lower pole converged at the L4 level, and the ureter from lower pole was obstructed near the junction. Retrograde insertion of a ureteral stent into the affected lower pole was unsuccessful, and instead the nephrostomy tube was inserted into the lower-pole urinary system. A left laparoscopic lower-pole heminephrectomy was planned after complete remission of left pyelonephritis.

FIG. 1.

Nonenhanced CT reveals left-sided duplex kidney with hydronephrosis and thinned parenchyma in the lower pole of the kidney (A–D).

After initiating the general anesthesia, the ureteral stent was inserted into the upper-pole calix cystoscopically and 0.25 mg/mL of ICG (Diagnogreen; Daiichi Pharmaceutical, Tokyo, Japan) was prepared. The patient was placed in a left-side-up flank position. We used a standard four-port placement strategy for transperitoneal laparoscopic kidney surgery. After mobilizing the descending colon, the left renal pedicles were exposed. We administered 2 mL ICG into the ureteral stent and then confirmed the position of the ureter connected to the upper pole of the kidney (Fig. 2B). During the lower-pole pelvis and affected ureter dissection, we encountered a significant amount of fibrotic tissue, likely owing to the patient's history of pyelonephritis. The ICG observation of the nonaffected ureter enabled us to dissect the affected ureter connected to the lower-pole pelvis. Then, only one renal artery and one renal vein secured each. Because the preoperative CT revealed that the lower-pole kidney was thin and atrophic, we speculated that the lower-pole kidney blood supply was reduced. However, the intravenous administration of 2 mL of ICG revealed a slight difference in blood flow between the upper and lower kidneys (Fig. 3C). We then decided to clamp the main renal artery during the cutting of the renal parenchyma. We also injected 20 mL of fivefold diluted ICG through a nephrostomy tube. The lower-pole kidney collecting system was viewed, which enabled us to capture an image of the upper- and lower-pole kidney parenchymal dissection plane (Fig. 2D). We clamped the left main artery and divided the parenchyma between the upper and lower poles using an ultrasonic scalpel (Harmonic Scalpel; Ethicon Endo-Surgery, CO) (Fig. 3A). Once we immediately encountered the urinary tract of the lower system, we dissected the tissue between the urinary system and the parenchyma (Fig. 3B), which preserved the upper-pole renal parenchyma as much as possible. After complete removal of the lower pole, hemostasis was achieved using a soft-coagulation system, and the clamps were removed. Parenchymal renorrhaphy was not carried out, and absorbable hemostats (TachoSil; CSL Behring) were placed on the resection bed (Fig. 3C). The operation time was 237 minutes, clamping time was 18 minutes, and the blood loss was 30 mL. Postoperative renal function was stable, and ultrasonography after 3 months postoperatively showed viable left upper-pole moiety remaining.

FIG. 2.

Intraoperative findings of the left kidney under white light and ICG-based NIRF imaging. (A) Gross appearance of left-sided duplex kidney under white light. (B) The administration of 2 mL of ICG into the ureteral stent inserted into the upper pelvis helps to identify the normal ureter. (C) The intravenous administration of 2 mL of ICG reveals comparable fluorescence between the upper and lower kidney. (D) The injection of 20 mL fivefold diluted ICG through a nephrostomy tube shows the collecting system of a lower pole. The dotted line indicates the border between upper and lower poles of the kidney. NIRF, near-infrared fluorescence; ICG, indocyanine green.

FIG. 3.

Intraoperative findings during resection. (A) The parenchyma is divided between the upper and lower poles using an ultrasonic scalpel. (B) The dissection between the urinary system and parenchyma. (C) The final appearance after resection. Absorbable hemostats are placed on the resection bed.

Discussion

Development of a duplex collecting system of the kidney is a relatively common anomaly. Heminephrectomy of the pathologic moiety is indicated since it is often associated with recurrent urinary tract infections. Recently, the results of a systematic review that assessed heminephrectomy outcomes in adults were reported.¹ Of the 66 patients (including laparoscopic 56 cases and robotic 5 cases), the authors concluded that a heminephrectomy may be effective in alleviating a patient's symptoms in addition to being safe when performed by experienced surgeons. However, all cases included in this systematic review were upper-pole nephrectomies for duplication of the upper-pole moiety. Roberts et al. reported that patients who underwent a laparoscopic lower-pole heminephrectomy had a comparatively higher complication rate.² Therefore, a lower-pole heminephrectomy is considered technically demanding and technical improvements are warranted.

ICG has been utilized intraoperatively during laparoscopic or robotic urologic procedures to help identify relevant anatomy and assess perfusion.³ It is especially used to confirm the blood flow of the renal parenchyma and to determine the tumor resection line during a partial nephrectomy.³ The utility of ICG during urinary tract reconstruction lies in its ability to identify the ureter, confirmation of stenosis, and blood supply assessment in the ureter.³ However, information on the use of ICG for heminephrectomies in patients with a duplex kidneys is limited. In this case, ICG was useful for several reasons. First, we could delineate the ureter of the nonaffected upper-pole pelvis by intraureteral injection of ICG. That enabled us to understand the precise anatomy between the upper pole and affected lower-pole ureters. Second, the intravenous ICG revealed the blood flow of the lower pole. In this case, the blood supply for the lower pole was comparable with that of the upper pole. Although clampless heminephrectomy was an option, we clamped the main renal artery to achieve bloodless view. Third, direct injection into the lower-pole pelvis through the nephrostomy tube revealed the precise position of the lower-pole urinary system. We could also identify the border between the upper and lower pole. We believe intraoperative ICG administration is useful for urologic laparoscopic or robotic surgery since they provide a better understanding of complex urinary tract anatomy for lower-pole heminephrectomies.

Conclusion

ICG administration by intravenous and intraureteral routes through both the ureteral stent and nephrostomy tube gives the surgeon useful anatomical information and facilitates laparoscopic lower-pole heminephrectomies in adult patients with duplex kidney.

Abbreviations Used

CT

computed tomography

ICG

indocyanine green

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received for this article.

Cite this article as: Kanno T, Takahashi T, Somiya S, Ito K, Higashi Y, Yamada H (2020) Indocyanine green fluorescence-guided laparoscopic lower-pole heminephrectomy for duplex kidney in adult, Journal of Endourology Case Reports 6:4, 384–387, DOI: 10.1089/cren.2020.0123.