complete ureteral triplication , the presence of three individual ureters originating from the kidney and draining into three separate orifices , is a rare congenital anomaly .
patients with such anatomy may be predisposed to recurrent infections , renal colic , and incontinence secondary to associated obstruction and reflux .
when patients with complete ureteral triplication require surgical management , the surgeon must evaluate the degree of renal compromise attributable to the pathologic portions of the urinary tract , and correctly distinguish the diseased portions of the urinary tract from its healthy counterparts .
it is for this reason that the role of perioperative imaging to guide operative treatment can not be overemphasized .
indocyanine green ( icg ) , a fluorescent dye that can be visualized under near - infrared fluorescence ( nirf ) , has been utilized intraoperatively during robotic urologic procedures to highlight relevant anatomy and assess perfusion .
icg may be visualized using the firefly system , which is integrated into the da vinci si robot ( intuitive surgical , sunnyvale , ca , usa ) .
herein , we describe a case in which both intraureteral and intravenous icg was used to facilitate a complex robotic partial nephroureterectomy in a patient with complete ureteral triplication .
a 31-year - old female with a congenital right ureteral triplication presented with recurrent right - sided pyelonephritis and persistent right - sided flank pain refractory to medical management . delayed phase
computed tomography ( ct ) scan with intravenous contrast clearly showed that each of the three right - sided ureters was associated with its own collecting system , and emptied separately into the bladder .
the uppermost moiety showed sequelae of chronic obstruction : significant parenchymal thinning , delayed contrast excretion , and dilated ureter .
the two inferior collecting systems and their associated ureters appeared to be emptying normally ( fig .
1 ) . mercaptuacetyltriglycine ( mag3 ) study showed symmetrical renal function with no evidence of obstructive uropathy bilaterally .
the uppermost moiety was not well delineated on the mag3 study . the patient elected for robotic right uppermost pole moiety nephroureterectomy .
the patient consented to off - labeled use of icg after a complete discussion of its risks and benefits .
we used cystoscopy and retrograde pyelography to show that the three separate right ureteral orifices were consistent with weigert - meyer law , and identify the ureter of interest ( fig .
2 ) . after preparing the ic - green ( akorn inc . , lake forest , il , usa ) by mixing 25-mg sterile icg in 10-ml distilled water , we used a 6-fr ureteral catheter to inject a 5-ml solution of icg retrograde into the lumen of the diseased ureter .
the patient was placed in right - side - up flank position with the table in full flexion .
we used our standard robotic port placement strategy for robotic nephroureterectomy that was previously described at our center .
after mobilizing the right colon , we turned on the firefly modality to locate the diseased ureter . under nirf , the diseased ureter fluoresced green while the other two healthy ureters did not fluoresce ( fig .
two weck hem - o - lok clips ( teleflex , morrisville , nc , usa ) were secured on the ureter at its junction with the bladder prior to transecting the ureter .
the diseased ureter was then dissected proximally to its associated renal pelvis . during our dissection of the uppermost pole renal pelvis
, we encountered a significant amount of fibrotic tissue , likely attributable to the patient 's history of recurrent pyelonephritis . by toggling the nirf on and off
, we were able to clearly distinguish between the green fluorescing renal pelvis and ureter , from the nonfluorescing fibrotic tissue .
after identifying the arterial and venous branches of the main renal artery and vein supplying the uppermost pole , we clipped the proximal and distal ends using two weck hem - o - lok clips and transected the vessels .
, there was a perfusion defect in the uppermost pole moiety of the kidney where we had removed its blood supply ; the remainder of the kidney was well - perfused and fluoresced green ( fig .
4 ) . utilizing nirf to delineate our margins , we excised the diseased collecting system and its blood supply en bloc .
ureteral triplication is a rare congenital anomaly ; only approximately 100 cases have been described in the literature .
smith classified ureteral triplication into four major variants : type 1 , complete ureteral triplication ( 35%)-three ureters originating from the kidney and emptying into three orifices ; type 2 , incomplete triplication ( 21%)-three ureters originating from the kidney , with two of these ureters joining to empty into two orifices ; type 3 , trifid ureter ( 31%)-three separate ureters originating from the kidney , with all three ureters joining to empty into a single orifice ; type 4 , double ureter , one bifurcated ( 9%)-two separate ureters originating from the kidney , with one ureter birfuricating into an " inverse y " to empty into three orifices .
our case was a type 1 , complete ureteral triplication with all three ureters associated with its own renal collecting system and emptying into three separate bladder orifices .
surgical management of patients with ureteral triplication , which may involve simultaneous treatment of the upper and lower urinary tracts , is most often indicated when there is a risk of renal compromise as in cases of veiscoureteral reflux , obstruction , ureteral ectopy , and recurrent infections .
given the variations in anatomy and increased predisposition for pathology , prudent use of perioperative imaging to guide surgical management of ureteral triplications is essential .
patel et al .   described the role of various preoperative imaging modalities on assessing anatomy and function in a patient with a type 2 ureteral triplication with ectopia .
a dimercaptosuccinic acid renal scan showed decreased perfusion and uptake by the right upper pole , suggesting a duplicated anomaly and ectopic ureter .
cystoscopy and retrograde pyelography demonstrated that there were two ureters originating from the right kidney that joined intramurally to form a single bladder orifice .
intravenous urography and ct scan revealed the ectopic third ureter , which was dilated and associated with the upper pole .
flechsig et al .   described using dynamic magnetic resonance nephrography to concomitantly assess anatomic and functional characteristics in a 5-year - old girl with a type 1 left ureteral triplication .
initial evaluation with a mag3 renal scan suggested poor renal excretion in the left lower pole , but the authors noted that precise localization of the impaired region was difficult due to limited resolution .
however , a dynamic magnetic resonance nephrography allowed for a detailed region - of - interest evaluation that showed 45% , 46% , and 9% function in the upper , middle and lower pole , respectively .
furthermore , the authors noted that the correlation between preoperative imaging and intraoperative findings assisted in performing laparoscopic partial nephroureterectomy .
an intraoperative imaging modality that assists in correctly identifying the pathologic ureter and associated renal pelvis , and in precisely determining the margin between compromised versus healthy renal parenchyma would facilitate surgical management of patients with ureteral triplication .
such an imaging modality would be particularly helpful during robotic surgery , as the surgeon relies solely on visual cues to guide dissection due to the lack of tactile feedback . despite this
, a means to intraoperatively image relevant anatomy and evaluate function in real - time during robotic surgical management of ureteral triplications has yet to be described .
icg has recently been increasingly utilized in urologic procedures as an intraoperative contrast agent to highlight relevant anatomy .
it is particularly helpful for intraoperative use as it has a low toxicity , high signal - to - noise ratio , and penetrates tissue .
first detailed the use of intravenous icg during robotic partial nephrectomy to differentiate normal renal parenchyma ( bright green fluorescence ) from tumors , cysts , and areas of fat necrosis ( decreased / no fluorescence ) .
bjurlin et al .   noted that intravenous icg may also be used to assess tissue perfusion during surgical management of the upper urinary tract .
poorly perfused fibrotic scar tissue appeared dark while well perfused renal pelvis and ureter appeared green .
we have found the use of intraureteral icg to assist in robotic ureteral reconstructions , which was first described at our center , to be particularly helpful in localizing the ureter despite severe periureteral inflammation and in determining margins of ureteral strictures . in our case , we utilized both intraureteral and intravenous icg intraoperatively to highlight relevant anatomy during robotic right uppermost pole nephroureterectomy in a patient with type 1 ureteral triplication .
intraureteral icg aided in accurately identifying the pathologic ureter and associated renal pelvis in real - time ; the system of interest fluoresced green while the other two systems did not fluoresce .
this aided our ability to focus our dissection to the ureter of interest without risking devascularization to the healthy ureters .
intravenous icg aided in assessing perfusion to the right kidney and delineating the margins of defective renal parenchyma in real - time ; the well - perfused middle and lower collecting systems fluoresced bright green , while the upper - most collecting system did not fluoresce as brightly . the use of intraureteral and intravenous icg to highlight relevant anatomy intraoperatively may be of particular benefit in patients with complex urinary tract anatomy , especially in cases necessitating concomitant operative management of upper and lower tracts .
 a patient with a complete right ureteral triplication presented with recurrent pyelonephritis and flank pain that was refractory to medical management . 
 evaluation showed that the atrophic upper - most renal moiety had been chronically obstructed and was associated with a dilated ureter . 
 intraureteral and intravenous indocyanine green ( icg ) were used as real - time contrast agents intraoperatively to facilitate right robotic partial nephroureterectomy of the diseased system . 
 intraureteral icg was used to accurately distinguish the pathologic ureter and associated renal pelvis from its normal counterparts . 
 intravenous icg was used to assess perfusion in the right kidney and delineate the margins of diseased renal parenchyma . 
INTRODUCTION
CASE REPORT
DISCUSSION