<title>1. BACKGROUND</title> <p>The minimally invasive surgical
(MIS) approach to vesicoureteral reflux disease was first described by Atala et al. in minipigs in 1993 and then first described in humans by Ehrlich et al. in
1994 [##REF##8326639##1##, ##REF##8116127##2##]. Since then, few pediatric centers have
embraced either the laparoscopic extravesical or vesicoscopic cross-trigonal
approaches owing to the technical challenges of fine suturing in the small
spaces. Success rates have been comparable to open surgical techniques and in 2004; Peters described his experience
using the surgical robot as an adjunct to both transvesical and extravesical
repairs [##REF##15474601##3##]. Since then, urologists have
watched robotic surgery becoming the standard of care in some adult urologic
procedures such as radical prostatectomy, but application in pediatrics has
been limited to a few centers where the robot has been accessible to pediatric
urologists.</p> <p>The surgical robot allows
clinicians improved dexterity, three-dimensional visualization, and motion
scaling, which helps dampen physiologic tremor.<italic/>
Due to these benefits, the reconstructive techniques required for
ureteral reimplantation are well suited for robotic surgery. In addition, due to the enhanced learning
curve with robotic surgery over pure laparoscopy, surgeons are able to utilize
the same techniques and suture size as would be used in open surgery. Major advantages over pure laparoscopic and
open techniques are 10X visual magnification and three-dimensional
visualization, and the ergonomic considerations of the robot console where the
surgeon sits during the procedure. The
limitations of robotic surgery are the added cost to the host institution, the
increased operative times required, and the support required from the ancillary
operative staff. Interestingly, these limitations
are the same experienced by the initial laparoscopists of the 90s.</p> <p>The key aspects of successful
robotic ureteral reimplantation surgery include appropriate patient selection,
proper patient positioning, an armamentarium of helpful techniques to
facilitate exposure, and an understanding of the limitations of the robot and
the complications potentially encountered.</p>
<p>Recommended by Hiep Nguyen</p> <p>Robotic-assisted laparoscopy (RAL) has become a promising means for performing correction of vesicoureteral reflux disease in children through both intravesical and extravesical techniques. We describe the importance of patient selection, intraoperative patient positioning, employing certain helpful techniques for exposure, and recognizing the limitations and potential complications of robotic reimplant surgery. As more clinicians embrace robotic surgery and more urology residents are trained in robotics, we anticipate an expansion of the applications of robotics in children. We believe that it is necessary to develop robotic surgery curricula for novice roboticists and residents so that patients may experience improved surgical outcomes.</p>
<title>2. PATIENT SELECTION</title> <p>In counseling our patients for the
options of surgical correction of vesicoureteral reflux, we rely heavily on the
individual patient's clinical picture.<italic/>
All patients are offered both endoscopic and formal surgical repairs,
whether by minimally invasive or open techniques. We detail peer-reviewed cited and personal
success experience for our patients and inform them of the variations in
success that can be expected in the face of higher grades of reflux and voiding
dysfunction. It is difficult to generalize or standardize patients, but typically, formal surgical repairs are
reserved for patients with higher grades of reflux, severe voiding dysfunction,
or in those with duplex systems. Patients with lower grades of reflux may be
more appropriate for intramural ureteral bulking agent implantation. When discussing robotic/laparoscopic
techniques versus open surgical techniques, we highlight the fact that open
surgery is the “gold-standard,” and MIS repairs appear to have similar success
rates as open surgery. Since we do not
discern pure laparoscopy from robotic-assisted laparoscopy because we believe
that the robot is merely another adjunct or tool to laparoscopy, we only
describe that we use the robot to assist with reconstructive surgeries.</p> <p>Patient comorbidities have not
played a major role in the decision for robotic repairs, however, patients with
severe pulmonary reserve deficits need to be carefully evaluated preoperatively
by anesthesia to determine if abdominal insufflation may impair ventilation. In addition, children with prior abdominal
surgery may require additional dissection in the abdomen to lyse any adhesions
that may obscure the line of sight to the pelvis.</p> <p>In our experience, patient's size
has not limited our decision for robotic surgery in part because it is unusual
to operate on children less than 6 months of age for vesicoureteral reflux and
because we have not found that the intuitive working port-to-camera port distance recommendations of 8–10 cm to be
applicable in small children. We have
successfully used interport distances of 5 cm without any arm collisions. We believe that this is due to the small
operative field and few large arm movements required once the robot is
appropriately set up and docked.</p> <title>3. PATIENT POSITIONING</title> <p>As with all robotic surgeries in
children, appropriate patient positioning is critical to the efficient progression
and success of the case. Since it is our
practice to perform cystourethroscopy prior to ureteral detrusorraphy surgery,
we place the patient in a low lithotomy position and prep the patient for both
cystoscopy and laparoscopic access at the same time. We angle the patient in 10 degree
Trendelenberg to encourage the bowel to fall out of the pelvis. For bilateral repairs, we choose to place
indwelling stents if the child has a history of a trabeculated thickened
bladder due to voiding dysfunction as we have observed postoperative edema at
the neotransmural tunnel causing transient obstruction. For the majority of cases, we typically will
place external ureteral catheters attached to a urethral catheter to help guide
ureteral dissection during the procedure. These are removed at the end of the surgery.</p> <p>Although some institutions have used
the vesicoscopic approach for ureteral reimplant surgery [##REF##16053348##4##, ##REF##17070297##5##], we use a
transperitoneal approach because we find that working spaces are not limiting
and we are more comfortable with this approach. We use a two-armed robot and place the camera port through the
umbilicus. The two working ports are
placed at the paramedian lines slightly below and on either side of the
umbilicus to avoid the inferior epigastric vessels (##FIG##0##Figure 1##). In children less than 15 kg, we have tended
to place the working ports at the level of the umbilicus to ensure a good
distance to the target site. For
bilateral cases, the robot is situated at the patient's feet in the midline;
however, for unilateral repairs we position the robot at the ipsilateral
foot. In addition, the ipsilateral
working port is placed slightly higher than the contralateral working port (see Figures ##FIG##1##2(a)##, 
##FIG##1##2(b)##). In small infants, we
place the camera port subxyphoid, to ensure a good working distance of the
camera to the target site (##FIG##2##Figure 3##).</p> <p>At our institution, we have found
that the most efficient way to set up our robotics room is with a fixed
location for the console and a relatively fixed location for the robot. We move the patient bed, the video cart, and
the instrument table depending on the access we desire. For reflux surgery, we position the tower on
either side for bilateral repairs or on the ipsilateral side for unilateral
repairs. This allows for easy access for the bedside assist and scrub tech to be on the contralateral 
side with the instruments. In the event that pure laparoscopy maneuvers are necessary, there is 
ample room.</p> <title>4. INTRAOPERATIVE TRICKS</title> <p>There are certain maneuvers which
are unique to laparoscopic/RAL surgery which assist in expediting the surgeries
and allow for the minimum number of ports to be placed. A sharp criticism of minimally invasive
surgery in children, especially small children, has been that open surgery
incisions are not as morbid as in adults and that the additive incisional
length of minimally invasive surgeries may equal and sometimes exceed the total
length of a single open surgical incision thereby theoretically causing more
postoperative pain. This argument is flawed because Blinman has demonstrated
that the sum tensions of port incisions do not equal the whole incisional
tensile burden as conjectured by some open surgeons [##UREF##0##6##]. We believe that the
smallest and fewest possible ports should be used to safely and effectively
perform MIS surgery, therefore, we employ the use of hitch-stitches to assist
in organ retraction throughout our cases [##REF##15474601##3##]. During an extravesical ureteral
reimplant, we routinely use monofilament suture placed through the lower
abdominal wall to aid in retraction of ureters and the bladder (##FIG##3##Figure 4##). During
creation and closure of the detrusor bladder flaps, we find that a hitch stitch
to help elongate the bladder anteriorly ensures proper length and straightening
of the tunnel. In addition, we use
anteriorly retracted stitches around the ureters to assist in laying the
ureters down in the detrusor tunnels. To lessen constant tension on the ureter
with this stitch, we routinely release the tension from outside of the abdomen
when retraction is not needed. When no
longer needed, these sutures are removed leaving only behind small needle
puncture marks on the suprapubic skin. For
children with more subcutaneous fat, we lengthen the hitch stitch needles by
partially flattening them (skiing).</p> <p>Throughout the creation of the
detrusor tunnel and the detrusorotomy, we intermittently insufflate the bladder
through the indwelling urethral catheter with a second insufflation unit to
ensure appropriate position of the ureter as described by Yeung et al. [##REF##15865516##7##]. We have used both manual fluid bladder
instillation for distention and gas insufflation and have found the gas to be
more rapid in raising and dropping the bladder and in the event of a small
mucosotomy which would require oversewing, the liquid distention tends to make
for a more tedious closure.</p> <title>5. COMPLICATIONS</title> <p>With the adoption of new
techniques, we have experienced some complications which can be attributed to
developing familiarity with minimally invasive reimplant surgery. When counseling families about the adverse
outcomes of ureteral reimplant surgery, we discuss urine leak, urinary
obstruction, and urinary retention. Casale et al. have published their
series of 41 bilateral extravesical RAL reimplants without any post-op urinary retention.
<italic/>They attribute the absence of retention, despite open surgical extravesical repair literature citing up to 10%
postoperative retention, due to the improved visualization of the neurovascular
bundle that is situated just lateral to the ureteral hiatus [##REF##11030542##8##, ##REF##18355846##9##]. On the other
hand, Peters encountered postoperative voiding dysfunction in his experience of
extravesical robotic reimplants [##REF##15474601##3##]. We have had only one patient who had mild
retention post-op and we anticipated this because of his preoperative urinary
retention history so we placed a percutaneous suprapubic tube at the time of
his reimplant surgery for postvoid drainage.<italic/>
His tube was removed 2 weeks later after his retention improved to less
than 10% of his functional capacity.</p> <p>Early in our experience, we had an
adolescent female present one week postoperatively with unilateral labial
swelling and abdominal pain. She was
found to have a unilateral ureteral leak just outside of the neohiatus and
required temporary stenting. The leak
sealed and her reflux was successfully treated confirmed by VCUG. It is possible that electrothermy dissection
near the ureteral insertion to the bladder may have caused this leak and since
then, only nonenergy dissection is used to raise detrusor flaps near the
ureteral hiatus. Another child with
severe elimination syndrome and a thickened bladder wall who underwent
bilateral ureteral reimplants developed transient postoperative ureteral edema
leading to azotemia. She required
temporary ureteral stenting after which her azotemia resolved. VCUG and US after stent removal confirmed
successful reflux resolution and no ureteral obstruction. In lieu of this outcome, we also advocate
stenting of children with solitary kidneys to avoid the possibility of
postoperative transient acute renal failure as recommended by Peters [##REF##15474601##3##].</p> <p>As described by Casale et al., we
have encountered the uterine artery in our female patients [##REF##18355846##9##]. During open
extravesical reimplants, the uterine artery is rarely identified, but with
abdominal insufflation, the bladder is situated anteriorly in the operative
field thereby giving the appearance that the ureter must be stretched to lay
down in the detrusor trough. The uterine
artery will appear to kink the ureter or press it posteriorly as it is laid
down in its detrusor trough. During
abdominal desufflation, however, one will see that the kinking is merely an
artifact of the distention.</p> <p>Beyond these early complications,
we have not witnessed subsequent urinary retention, urine leak, or ureteral
stenosis as identified by any <italic>de novo</italic> hydronephrosis. In addition, we have had
three VCUG-documented reflux management failures or reflux down grades and one
case of <italic>de novo</italic> contralateral reflux
out of 16 patients. All failures have
been in children with varying reflux grades and the only common element of
these children has been a history of pre-existing elimination syndrome, a
factor well known to reduce antireflux surgery success.</p> <title>6. FUTURE PERSPECTIVES</title> <p>Initial reports of the success of
RAL reimplant surgery seem to rival open surgical repairs. To date, MIS surgery in children has
demonstrated equivalence to open surgery with additional cost. The advantages of robotic surgery in children
are harder to demonstrate than in adults since metrics used in the adult
literature to show advantages do not always apply to children. The financial cost from loss of work
productivity is more measurable than the impact of missed days of school. In addition, few have looked at the financial
impact of a working parent having to stay at home to care for a postoperative
child. Pain score assessments between
open and MIS surgeries have not been rigorously tested as randomized trials
looking at open versus robotic urologic surgeries in children are nonexistent. Formal multi-institutional prospective
studies looking at matched open and RAL VUR patients are required.</p> <p>The advantages for advancing
robotics in children will be the greatest in residency education and
patient-specific surgical simulation (##FIG##4##Figure 5##). With the aid of preoperative imaging, a
surgeon or resident will be able to perform the surgery in a virtual reality
arena prior to performing the surgery on the actual child. MIS surgery lends itself to task
deconstruction better than open surgical procedures and we believe that in the
era of surgical simulation training, robotic surgery will allow residents and
novice roboticists to acquire technical competence in procedure performance
more rapidly than open surgical procedures. The development of robotic surgery curricula
will be necessary to achieve the highest level of patient outcomes.</p>
<fig id="fig1" position="float"><label>Figure 1</label><caption><p>Port placement, bilateral reimplants. X = camera port, black dots = working ports.</p></caption></fig> <fig id="fig2" position="float"><label>Figure 2</label><caption><p>(a) Port placement, right reimplant; (b) port placement, left reimplant.</p></caption></fig> <fig id="fig3" position="float"><label>Figure 3</label><caption><p>Port placement, small children or short-waisted children, bilateral reimplants.</p></caption></fig> <fig id="fig4" position="float"><label>Figure 4</label><caption><p>Demonstration of <italic>hitch stitch</italic> around right ureter for
retraction (2-0 monofilament).</p></caption></fig> <fig id="fig6" position="float"><label>Figure 5</label><caption><p>Patient-specific virtual reality robot docking simulation (Courtesy of MIMIC Technologies, 
Inc., Seattle, WA, USA).</p></caption></fig>
<graphic xlink:href="AU2008-732942.001"/> <graphic xlink:href="AU2008-732942.002"/> <graphic xlink:href="AU2008-732942.003"/> <graphic xlink:href="AU2008-732942.004"/> <graphic xlink:href="AU2008-732942.005"/>
[{"label": ["6"], "surname": ["Blinman"], "given-names": ["T"], "article-title": ["Trocar incision tensions do not sum"], "conf-name": ["In: Proceedings of the 16th Annual Congress for Endosurgery in Children (IPEG '07)"], "conf-date": ["September 2007"], "conf-loc": ["Buenos Aires, Argentina"], "publisher-name": ["International Pediatric Endosurgical Group"], "comment": ["Abstract S009"]}]
Adv Urol. 2008 Aug 3; 2008:732942