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15. Semins MJ, Trock BJ, Matlaga BR. The safety of ureteroscopy dur-
ing pregnancy: a systematic review and meta-analysis. J Urol.
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renal surgery, shockwave lithotripsy, and percutaneous nephroli-
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17. Takazawa R, Kitayama S, Tsujii T. Successful outcome of flexible ure-
teroscopy with holmium laser lithotripsy for renal stones 2 cm or
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18. Grasso M, Ficazzola. Retrograde ureteropyeloscopy for lower pole
caliceal calculi. J Urol. 1999;162:1904-8.
19. Bozkurt OF, Resorlu B, Yildiz Y, Can CE, Unsal A. Retrograde intrare-
nal surgery versus percutaneous nephrolithotomy in the manage-
ment of lower-pole renal stones with a diameter of 15 to 20 mm. J
Endourol. 2011;25:1131-5.
20. Mariani AJ. Combined electrohydraulic and holmium:YAG laser
ureteroscopic nephrolithotripsy of large (greater than 4 cm) renal
calculi. J Urol. 2007;177:168-73.
Hand-Assisted, Conventional and Lapar-
oendoscopic Single-Site Surgery for Par-
tial Nephrectomy without Ischemia Using
a Microwave Tissue Coagulator
Tetsuo Nozaki, Yoshihiro Asao, Tomonori Katoh, Kenji Yasuda, Hideki Fuse
Correspondence Author:
Tetsuo Nozaki, MD
Department of Urology, Graduate
School of Medicine and Pharma-
ceutical Sciences for Research,
University of Toyama, 2630 Sugitani,
Toyama 930-0194, Japan.
Tel: +81 76434 2281
Fax: +81 76434 5039
E-mail: nozaki0921@yahoo.co.jp
Received May 2013
Accepted January 2014
Department of Urology, Gradu-
ate School of Medicine and
Pharmaceutical Sciences for
Research, University of Toyama,
2630 Sugitani, Toyama 930-
0194, Japan.
Purpose: We report our experience of minimally invasive partial nephrectomy without is-
chemia using a microwave tissue coagulator (MTC) for hand-assisted laparoscopic partial
nephrectomy (HALPN), conventional laparoscopic partial nephrectomy (CLPN), and lapar-
oendoscopic single-site surgery for partial nephrectomy (LESSPN). We retrospectively com-
pared the results of these techniques to better define the individual role and the benefits.
Materials and Methods: From July 2005 to September 2012, 28 patients with small and exo-
phytic renal tumors underwent HALPN (n = 12), CLPN (n = 10) and LESSPN (n = 6). In these
procedures, the surgeon used an MTC for circumferential coagulation around the tumor. After
coagulation, the tumor was resected without renal pedicle clamping.
Results: The mean operative time was 259, 194 and 174 min for the HALPN, CLPN and
LESSPN groups respectively. Two patients (one in HALPN group and one in LESSPN
group) converted to laparotomy due to an inability to maintain hemostasis; however, there
were no conversions to ischemic partial nephrectomy or radical nephrectomy. No differences
between HALPN, CLPN and LESSPN were noted in terms of estimated blood loss, measured
analgesic requirements, outcomes, or complications.
Conclusion: We believe that these techniques are feasible and that they minimize the risk of
unexpected collateral thermal damage by appropriate MTC needle puncture. When deciding
to use HALPN, CLPN or LESSPN, our findings suggest that the choice of surgical approach
should depend on the patient’s individual circumstance.
Keywords: carcinoma, renal cell; surgery; laparoscopy; microwaves; nephrectomy; organ
sparing treatments; surgical procedures; minimally invasive; methods.
LAPAROSCOPIC UROLOGY
1596 | Laparoscopic Urology
INTRODUCTION
Laparoscopic partial nephrectomy (LPN) is becom-ing a popular treatment option for small renal tu-mors because it offers better cosmesis and reduces
postoperative pain.(1,2) As LPN gains widespread accept-
ance, there is a great need for a novel surgical technique
to be reliable and provides bloodless resection of the renal
parenchyma without damaging the residual renal tissue.(3)
In Japan, microwave tissue coagulators (MTCs) are widely
used for LPN.(4,5) In LPN, the MTC is applied peripher-
ally in the healthy parenchyma surrounding the tumor, with
circumferential punctures that produce coagulation of a
conical-shaped portion of tissue. Subsequently, a wedge re-
section can be achieved in the bloodless field without renal
pedicle clamping.
The aim of this study was to compare the various techniques
of LPN such as hand-assisted laparoscopic surgery for PN
(HALPN), conventional LPN (CLPN) and laparoendoscop-
ic single-site surgery (LESS) for PN (LESSPN) as well as
their outcome in terms of operative time, postoperative pain
and surgical site infection.
MATERIALS AND METHODS
A retrospective study was carried out including patients op-
erated on at Toyama University Hospital from July 2005 to
September 2012. Of the 28 patients included in the study,
12 were in the HALPN group, 10 were in the CLPN group
and 6 were in the LESSPN group. We began our study us-
ing HALPN and then we gradually shifted to CLPN and
LESSPN; indeed, from 2005-2008, 2007–2012 and 2011–
2012, we performed HALPN, CLPN and LESSPN, in that
order. Choice of a particular surgical approach was based
on the surgeon’s clinical judgment, taking into considera-
tion patient and clinical factors. During this study, a sin-
gle surgeon performed all preoperative counseling and
surgery. The demographic characteristics are summarized
in Table 1. All renal tumors were categorized according to
the nephrometry score determined from preoperative imag-
ing as low, moderate and high complexity.(6) Each group
was comparable with regard to age, body mass index, and
nephrometry scoring. In the LESS group, all patients un-
derwent surgery after obtaining Institutional Review Board
approval from the ethical committee and informed patient
consent. Both transperitoneal and retroperitoneal approach-
es were taken at the surgeon’s discretion. All lesions were
suspected of renal cell carcinoma (RCC), as were periph-
erally located and exophytic renal tumors with at least 5
mm of normal renal tissue between the tumor margin and
the collecting system. Outcome was assessed in the form
of operative time, blood loss, in-hospital frequency of an-
algesia administration and overall complication rates. All
complications were carefully graded using the modified
Clavien system.(7) Renal function was determined by serum
creatinine (mg/dL) measurement and postoperative serum
creatinine was measured at 7 postoperative days.
Statistical Analysis
Non-parametric statistical analyses (Mann-Whitney U test
for two-way, and Kruskal-Wallis test for three-way analy-
ses) were used for statistical analyses.
HALPN Surgical Technique
The HALPN technique used has been described in detail
elsewhere.(8) Briefly, HALPN was carried out as follows.
Under general anesthesia, each patient was placed in a
70-degree lateral decubitus position. After an approximately
7 cm skin incision was made around the umbilicus, a hand-
assisted device, GelPort (Applied Medical, Rancho Santa
Margarita, CA) and two or three additional ports are placed.
The kidney was mobilized within Gerota’s fascia with the
aid of the surgeon’s hand. The Gerota’s fascia was incised
to expose the tumor and surrounding normal renal capsule.
The renal pedicle was not dissected. Intra-abdominal ultra-
sound scanning was used to confirm the tumor shape, size
and the depth of the tumor base. The incision line, which
was 1 cm from the tumor margin, was marked circumfer-
entially on the renal capsule using electrocautery scissors.
Next, the surgeon grasped the surgical handpiece of the
MTC (Microtaze OT-110M, Aswell Co., Osaka, Japan),
which was originally designed for open surgical procedure,
and introduced it through the GelPort with the coaxial flex-
ible cable. The MTC causes the thermal coagulation of tis-
sues using microwave energy (2,459 MHz). This energy
is transmitted from a generator through a coaxial cable to
a probe, which consists of a handpiece and a needle-like
electrode. The rapid oscillation of water particles caused by
microwaves results in a high temperature and induces cone-
shaped tissue coagulation around the needle that is 7 to 10
1597Vol. 11 | No. 03 | May - June2014 |U R O LO G Y J O U R N A L
LESS for Partial Nephrectomy | Nozaki et al
mm in width without carbonization. The needle applicator
consists of a 10-, 15-, or 20 mm long electrode. The length
of antenna needle inserted changes depending on the depth
of coagulation. The surgical handpiece of MTC could easily
be inserted through the GelPort, but attention was needed
to avoid injuring other organs. Needle puncture was per-
formed every 7 to 10 mm along the demarcation line. The
direction and angle of the needle puncture could be easily
and precisely changed in a timely manner depending on the
site of coagulation. Microwave coagulation was carried out
at 75 W for 45 sec, followed by 15 sec of dissociation. After
coagulation, the tumor rose from the kidney and the base of
the tumor was resected using a combination of laparoscopic
scissors and blunt finger dissection. The excised tumor was
removed through the GelPort, and biopsies from the tumor
bed were sent for frozen-section study to confirm complete
tumor removal. Indigo carmine (indigotindisulfonate sodi-
um) was intravenously injected to investigate the presence
of urine leakage. After ensuring that there was no further
bleeding from the tumor bed, a drainage tube was placed
around the tumor bed.
CLPN Surgical Technique
At the beginning of the operation, four to five trocars were
inserted transperitoneally or retroperitoneally. After tumor
exposure and intra-abdominal ultrasound examination, a
laparoscopic MTC probe (Microtaze OT-110M, Aswell
Co., Osaka, Japan) that bends at its distal near-object end
was introduced through the 5 mm port. Using the bendable
laparoscopic MTC probe, microwave coagulation was ap-
plied peripherally to the healthy parenchyma surrounding
the tumor, with circumferential punctures producing coagu-
lation of a conical-shaped portion of tissue (Figure). Sub-
sequently, the base of the tumor was resected using a com-
bination of conventional 5 mm laparoscopic scissors and
blunt dissection with a laparoscopic aspirator without renal
pedicle clamping. The specimen was placed in the laparo-
scopic bag and retrieved through the abdominal incision.
Subsequently, the procedure was performed the same as in
HALPN.
LESSPN Surgical Technique
The LESSPN technique used has been described in detail
elsewhere.(9) Briefly, LESSPN was carried out as follows.
Through the retroperitoneal approach, a 3 cm transverse
skin incision was made just below the tip of the 12th rib, and
the extraperitoneal space was carefully dissected with the
index finger. The retroperitoneoscopic working space was
dilated using a Preperitoneal Dissector Balloon (PDB1000;
Covidien, Mansfield, MA, USA) under the direct vision
of a laparoscope. Through the transperitoneal LESSPN
approach, to enhance the cosmetic result, we developed a
unique intraumbilical technique whereby the umbilicus was
completely extroflexed and a skin incision of approximately
3 cm in length was made longitudinally. After subcutaneous
tissue dissection and fascial incision, the peritoneum was
incised. Next, a LapProtectorTM (Hakko Medical Indus-
try, Tokyo, Japan) was set up through the small incision.
The LapProtectorTM offers wound protection and 360° of
atraumatic wound retraction, which was maximized in or-
der to pass surgical instruments into the abdominal cavity.
Then, an EZ accessTM (Hakko Medical Industry, Tokyo,
Table 1. Demographic characteristics of study group.
Variables HALPN CLPN LESSPN P
Age (years) 67.2 ± 10.2 53.3 ± 15.2 56.3 ± 18.3 .121
BMI (kg/m2) 23.9 ± 3.1 25.5 ± 3.5 23.1 ± 0.6 .581
Tumor size (cm) 1.9 ± 0.42 2.8 ± 1.5 1.8 ± 0.8 .097
Imperative case (no.) 2.0 0.0 1.0 .484
Nephrometry sum 5.08 ± 1.31 5.00 ± 1.09 5.16 ± 0.98 .584
Low, 4-6 score (%) 10 (83.3) 9 (90) 6 (100) ---
Medium, 7-9 score (%) 2 (17.7) 1 (10) 0 (0.0) ---
High, 10-12 score (%) 0 (0.0) 9 (0.0) 0 (0.0) ---
Keys: BMI, body mass index; HALPN, hand-assisted laparoscopic partial nephrectomy; CLPN, conventional laparoscopic partial nephrectomy;
LESSPN, laparoendoscopic single-site surgery for partial nephrectomy.
1598 |
Japan), a silicone cap designed to cover the outer ring of
the LapProtectorTM, was set up in order to maintain the
pneumoperitoneum. The EZ accessTM allows the insertion
of multiple trocars (three to four) freely into the abdominal
cavity through its large surface area (5 cm diameter). The
trocars could be positioned anywhere within the silicone
cap; they were separated as far as possible from each other
on the silicone cap, which more readily facilitated the spac-
ing of instruments. The silicone cap is flexible and self-seal-
ing; it acts as a pseudoabdominal platform for the trocars.
If the surgeon wanted to change the trocar position and/or
trocar size, the pore on the silicone cap was resealed after-
wards. At the beginning of the operation, three 5 mm trocars
were inserted into the silicone cap before it was mounted
onto the LapProtectorTM. The abdominal cavity was ex-
plored using a flexible 5 mm 0° Olympus high-definition
laparoscope (Tokyo, Japan). Except for a reusable bend-
able laparoscopic MTC probe, all other instruments were
conventional straight laparoscopic instruments, including a
bipolar grasper, laparoscopic scissors, and a suction device.
After exposure of the tumor, the 5 mm trocar was replaced
with a 12 mm trocar to enable intra-abdominal laparoscopic
ultrasound scanning. After ultrasound examination, the 12
mm trocar was replaced with the 5 mm trocar. There was
no leakage of the pneumoperitoneum during multiple tro-
car exchanges using the EZ accessTM. Using the bendable
laparoscopic MTC probe, the direction and angle of needle
puncture could be easily and precisely changed in a timely
manner depending on the site of coagulation, even with the
LESS procedure. After coagulation, the base of the tumor
was resected using a combination of conventional 5 mm
laparoscopic scissors and blunt dissection using a laparo-
scopic aspirator under normal renal perfusion. The excised
specimen can be removed by simply removing the silicone
cap from the proximal ring.
RESULTS
The perioperative and postoperative variables are detailed
in Table 2. No significant differences were noted in the
operative time, estimated blood loss and complication
rates. There were two conversions to laparotomy (one in
the HALPN group and one in the LESSPN group) as a re-
sult of an inability to maintain hemostasis; however, there
were no conversions to ischemic partial nephrectomy or
radical nephrectomy. With the exception of these two pa-
tients, complete hemostasis was achieved; therefore, the
application of bolster, sealant or parenchymal stitches/col-
lecting system closure was not necessary. The in-hospital
frequency of analgesia administration was comparable be-
tween groups. All patients resumed oral intake and were
ambulatory within 2 days. No postoperative complications
such as delayed hemorrhage were observed in follow-up
computed tomography (CT) imaging. However, one patient
(16.7%) in the LESSPN group developed urinoma forma-
tion, which was resolved with percutaneous drainage and
ureteral stent placement. Wound infection and dehiscence
Table 2. Perioperative parameters, outcomes and complications.
Variables HALPN CLPN LESSPN P
(n = 12) (n = 10) (n = 6)
Mean operative time (min) 259 ± 75.2 194 ± 53.5 174 ± 13.8 .064
Mean blood loss (mL) 298 ± 69 48 ± 6 892 ± 40.0 .128
Complications* (no.)
Wound dehiscence 1.0 0.0 0.0
Urine leakage** 0.0 0.0 1.0
Frequency of analgesic use (no.) 1.16 ± 1.06 1.5 ± 1.37 1.16 ± 0.57 .831
Delay in resuming normal activity (days) 1.3 ± 0.4 1.1 ± 0.4 1.0 .264
Delay in resuming normal diet (days) 2.1 ± 0.5 2.3 ± 0.8 1.5 ± 0.6 .055
Postoperative/preoperative serum creatinine (%) 106.0 ± 10.5 114.3 ± 13.8 112.4 ± 19.2 .451
Keys: HALPN, hand-assisted laparoscopic partial nephrectomy; CLPN, conventional laparoscopic partial nephrectomy; LESSPN, laparoendoscopic
single-site surgery for partial nephrectomy.
* Complications classified using the modified Clavien System.
** Urine leakage requiring ureteral stent.
Laparoscopic Urology
1599Vol. 11 | No. 03 | May - June2014 |U R O LO G Y J O U R N A L
occurred in one patient (8.3%) in the HALPN group in the
perioperative period, which was resolved with conservative
treatment. The mean postoperative/preoperative creatinine
(mg/dL) was 1.06, 1.14, and 1.12 for the HALPN, CLPN
and LESSPN groups (P = .451), respectively.
In LESSPN, the EZ access, with its relatively large diam-
eter (5 cm), facilitated the triangulation and spacing of in-
struments, despite actually operating through a smaller 3
cm skin incision. Even in LESS surgery, internal and ex-
ternal instrument collision did not prevent the completion
of the procedures. The abdominal view after the unique in-
traumbilical technique revealed an invisible umbilical scar.
During the follow-up period, we observed one recurrence
in the HALPN group despite a 100% negative margin
rate. This patient had previously undergone contralateral
nephrectomy for RCC. Two suspicious renal tumors were
discovered in the remaining lower and middle pole kidney
in follow-up imaging studies. Both tumors were resected
simultaneously, and intraoperative frozen section analysis
and final pathologic examination revealed negative mar-
gins. However, local recurrence and pulmonary metastases
developed 8 months after HALPN. With the exception of
this case, no local recurrence or distant metastases occurred
during our midterm follow-up periods (mean 42.6 months
post procedure).
DISCUSSION
Although the MTC is a useful instrument that enables sur-
geons to perform LPN without renal pedicle clamping, one
possible drawback of the MTC may be collateral thermal
damage to surrounding structures, such as arteries, veins
and the collecting system as a result of inadequate coagu-
lation. This technique is better suited for polar tumors or
small exophytic tumors located on the lateral convexity of
the kidney. The indication for this procedure must be lim-
ited to small (< 4 cm) exophytic renal tumors with adequate
intervening renal parenchyma as far as the renal collect-
ing system (< 5 mm). Therefore, this technique cannot be
applied to central or hilar tumors. While limiting the indi-
cation, as a result of inappropriate needle puncture, unex-
pected postoperative complications, such as postoperative
urinoma formation, pelvicaliceal stenosis, renal infarction
or renal arteriovenous fistula, were reported.(5,10) Consider-
ing that these complications have rarely been documented
in open partial nephrectomy (OPN) using the MTC, this
should be recognized as a potential risk associated with
the laparoscopic approach. The MTC probe, which was
designed for purely laparoscopic surgery, is rigid and its
movement is restricted by the fixed port site.(11) To insert the
needle in the appropriate direction, it is mandatory to fully
mobilize the antenna needle in the intraperitoneal space as
in standard open surgery without stress. To allow the safe
and widespread use of this apparatus in LPN, further in-
novative methods for precise needle puncture are needed.
In an attempt to provide more precise and accurate coagu-
lation, we propose the application of an “open” MTC for
HALPN.(8) Hand-assisted laparoscopic surgery (HALS) is
a unique surgical approach that has several unique advan-
tages (e.g., surgeons can insert a hand into the abdomen to
achieve tactile sensation, three-dimensional orientation,
hemorrhage control and improved organ retraction and re-
moval, analogous to laparotomy.(12,13) In HALPN using the
MTC, needle puncture in the appropriate direction was quite
easy and could be precisely changed in a timely manner.
Moreover, digital dissection allows better access and quick
isolation of the tumor. As such, this technique does not re-
quire advanced laparoscopic skill. In our series, HALPN
was an effective procedure, and all measurable periopera-
tive outcomes are equivalent, with no obvious disadvantage
for HALPN. Although not significant, the longer operative
time observed for HALPN group potentially reflects under-
Figure. The microwave tissue coagulator is applied peripherally
in the healthy parenchyma surrounding the tumor.
LESS for Partial Nephrectomy | Nozaki et al
1600 |
lying bias due to the fact that HALPN patients were more
likely to be undergoing surgery during the early experience
of using the MTC. However, in one patient, wound infec-
tion and dehiscence occurred. The primary disadvantage
of HALPN compared to CLPN and LESSPN is the larger
incision. A large series summarizing the specific complica-
tions of HALS has been reported.(14-16) These reports sug-
gested that postoperative HALS incision site complications,
including wound infections and hernias, occur more often
than with standard laparoscopy. An incisional hernia is often
associated with significant morbidity and usually requires
an additional procedure for its repair, which is associated
with recurrence. Various risk factors for the development of
postoperative complications at the HALS incision site have
been proposed, including patient factors (smoking, diabe-
tes, renal failure and obesity), wound factors (re-incision,
midline incisions and wound infection), external factors
(radiation and chemotherapy) and operative variables (pro-
longed operative time and lack of antibiotics). The surgeon
should take these into account when considering HALPN,
and should bear these postoperative complications in mind
during the surgery.
To increase the cosmetic result of the surgery and to mini-
mize patient discomfort, several authors successfully uti-
lized LESSPN.(17-19) In this study, we attempted LESSPN
without ischemia using the MTC. It is of note that the
incidence of benign disease is high (approximately 30%)
in small asymptomatic renal tumors.(20,21) The cosmetic
outcome is a significant issue and a lower morbidity ap-
proach should be strongly recommended. CLPN is rou-
tinely performed using more than four ports of entry into
the abdomen. The use of multiple puncture sites, however,
may decrease patient cosmetic satisfaction and could in-
crease trocar-associated complications, such as trocar-site
bleeding, herniation of viscera and wound infection. In this
setting, LESSPN could play a principal role in increasing
patient satisfaction because LESS avoids the psychological
trauma associated with multiple scars. Despite recent tech-
nologic advances in LESS instrumentation and optics, there
are concerns associated with technical difficulties, includ-
ing internal or external instrument collisions or difficulties
in driving the instruments. In order to allow the safe use of
this apparatus in LESSPN, further innovative methods for
precise needle puncture are needed. In our LESSPN group,
we used the EZ access port and bendable MTC probe for
PN without ischemia. Using these new types of devices for
LESSPN, the surgeon did not encounter internal or external
instrument collisions or difficulties in driving the instru-
ments, problems that were typical of LESS procedures. The
analysis of our first six LESSPNs is encouraging and com-
pares favorably with other LESSPN without ischemia se-
ries. Kaouk and colleagues published their experience with
five cases of LESSPN without ischemia using a harmonic
scalpel.(17) The mean operating time was 160 min, with a
mean estimated blood loss of 420 mL. They converted to
standard laparoscopy in one patient to control parenchymal
bleeding. Cindolo and colleagues published their experi-
ence with six cases of LESSPN without ischemia using a
laparoscopic vessel sealing instrument (LigaSure Advance,
Covidien, Mansfield, MA).(18) The average tumor size was
2.1 cm (range 1.0-3.5 cm) and mean operating time was
148 min (range 115-180 min), with a mean estimated blood
loss of 201 mL. They added one additional 5 mm port in
two cases to suture the renal parenchyma and for liver or
tissue retraction. They converted to standard laparoscopy
(adding two 5 mm ports) in one case to control parenchy-
mal bleeding. Our procedure provides optimal hemostasis,
making LESSPN easier and possible without renal pedicle
clamping or hemostatic sutures. This technique should only
be attempted in select patients who have favorable tumor
anatomic features and should be performed by an expe-
rienced laparoscopic team. The only recognized benefit
of LESS compared with conventional laparoscopy is im-
proved cosmesis. The other potential patient benefits such
as a decrease in postoperative pain and recovery time are
equivalent, with no obvious advantage for LESSPN. How-
ever, in our LESSPN group, one patient (a 22-year old fe-
male) with Von Hippel-Lindau disease was included. The
retroperitoneal LESS approach was chosen to minimize the
intra-abdominal adhesion and limit abdominal wall trauma.
We postulate that the younger patient subset, which was
more likely to undergo surgery for benign indications and
more likely to undergo repeat surgery for recurrence dis-
ease, received the greatest benefit from LESS surgery.
This study has several limitations. First, the study is ret-
rospective and is susceptible to all limitations and biases
Laparoscopic Urology
1601Vol. 11 | No. 03 | May - June2014 |U R O LO G Y J O U R N A L
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nal cell carcinoma >4 cm in size? Nat Clin Pract Urol. 2008;5:482-3.
inherent in a retrospective design. Second, we used the fre-
quency of analgesia administration as a surrogate for meas-
uring postoperative pain. The optimal means of assessing
postoperative pain would involve using a visual analog
scale as well as measuring analgesic requirements. Third,
the study includes a relatively small number of patients and
a relatively short follow-up period. Further studies are nec-
essary to investigate the actual benefits of these procedures
in performing minimally invasive nephron sparing surgery.
CONCLUSION
In conclusion, HALPN, CLPN and LESSPN without is-
chemia by using MTC were feasible and safe. Our prelimi-
nary findings can be used to better counsel patients when
deciding between a HALPN versus CLPN or LESSPN ap-
proach. The surgical outcomes were not significantly differ-
ent and the choice of surgical approach therefore depends
on the patient’s individual circumstance.
CONFLICT OF INTEREST
None declared.
LESS for Partial Nephrectomy | Nozaki et al