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Lauren J Smith
Christchurch School of Medicine
Otago Medical School
University of Otago
Mr Kevin Bax
Urologist at Christchurch Hospital
Clinical Senior Lecturer
University of Otago, Christchurch
Abstract
Robotic assisted partial nephrectomy (RAPN) is not currently of-
fered in the public health system in New Zealand, but current re-
search suggests there may be reduced complications and length of
stay compared to open partial nephrectomy (OPN). The objective
of this study was to retrospectively compare RAPN and OPN ap-
proaches in Canterbury, between Jan 2015–Oct 2018. The study
showed no significant difference in all baseline characteristics be-
tween the two groups (p < 0.05), except positive resection margin,
which showed a higher number with a resection margin (<1 mm for
OPN vs. RAPN; 11 vs. 0, p = 0.0048). There was significant reduc-
tion in mean length of stay for RAPN (2.3 vs. 4.3 days, p = 0.0001)
and number of complications (2 vs. 22, p = 0.0002) compared with
OPN respectively. There was no significant difference in other peri-
operative variables. This study is consistent with current literature,
showing a reduction in length of stay and number of complications for
RAPN compared with OPN, and a lower rate of positive resection
margins. Costs of providing RAPN therefore need to be considered
to determine if there is justification for providing this service in the
public health system. Future research could investigate using a longer
follow-up period to analyse oncological outcomes, such as metastatic
spread and recurrence.
Introduction
Current guidelines suggest removal of small renal masses (<4 cm)
with nephron-sparing surgery when suspicious of malignancy. 1,2 Renal
masses larger than this would impair a large proportion of the kidney,
therefore an inability to preserve its function in nephron-sparing sur-
gery. Nephron-sparing surgery is used to maintain the patient’s kid-
ney function, reducing risk of progression to chronic kidney disease. 1,2
There is no difference in oncological outcomes (local/metastatic
spread and recurrence) with tumours measuring <5 cm, therefore
this is the treatment of choice if technically feasible, unless the tumour
has suggestions of increased oncological potential. 2
There are now many different approaches to nephron-sparing sur-
gery: open, robotic, and laparoscopic. The laparoscopic approach is
not often chosen due to its difficulty for many tumour locations, or
for obese patients who increasingly make up the patient population.
OPN is most often used in the public sector, but RAPN can now be
used as a minimally invasive alternative to OPN in the private sector
of New Zealand with the hope of reducing complications and enhanc-
ing performance. Two meta-analyses showed lower rates of compli-
cations with RAPN, as well as shorter length of stay and reduced
transfusion requirements, compared with the OPN approach. 3,4 Xia
et al carried out sensitivity analysis with exclusion of studies with ob-
vious selection bias with regard to tumour complexity, allowing more
accurate analysis of intra-operative factors. 3 Tsai et al also showed
reduced blood loss for RAPN compared to OPN, particularly in high-
ly complex renal masses, but also a longer operative time. 4 Xia et al
and Tsai et al both had a large sample size, but inherent limitations
involved in observational study. 3,4
A reduction in mean length of stay with RAPN compared with OPN
was demonstrated by several retrospective and prospective studies
carried out since 2016. 5–9 Two retrospective studies also showed a
reduction in intraoperative transfusion rates 5,6 and complications 8,10
with RAPN compared with OPN.
Overall, there is a need for well-designed randomised control trials
with large sample sizes and longer follow-up times, as well as studies
using local data. Robotic surgery is not currently used in the public
health system in Canterbury, therefore it would be useful to analyse
the patient benefit of RAPN compared with OPN using local data. If
local data aligns with current literature showing a significant patient
benefit, then a cost-benefit analysis could be carried out to determine
the feasibility of its use in the Canterbury public health system. For
this reason, a retrospective analysis was carried out comparing RAPN
with OPN using patients in Canterbury. The aim of this study was
to determine if there is any difference between RAPN and OPN in
Canterbury with regard to perioperative variables and complications.
Methods
Study design and data collection
Data from all patients undergoing OPN in the Urology Department
of Christchurch Hospital were retrospectively collected between Jan
2015–Oct 2018. All patients undergoing RAPN by the Urology Asso-
ciates (private urologists in Canterbury) between these dates were
also included. Exclusion criteria were paediatric patients or patients
who were not undergoing tumour removal.
For each patient, we collected data on age, gender, perioperative fac-
tors (operative and ischaemic time, blood loss, peri- and post-opera-
tive complications within 30 days, and hospital stay), and tumour char-
acteristics (tumour size, histotype, stage, and surgical margin status).
Positive resection margin is the margin of surgical tissue that has no no-
table tumour within the resected tissue, determined through histology.
Data was collected through a combination of electronic records and
operative notes, by two different people. Tumour size was deter-
mined using information from histology, and complications were re-
corded according to the Clavien-Dindo classification. 11 This is a classi-
fication system, which grades complications from 1–5, grade 5 being
most severe.
Statistics
Categorical variables were compared using Fisher’s exact two-tailed
test, while continuous variables were compared, calculated using
the unpaired t-test. All statistical analyses were carried out using
Graphpad Prism.
Results
Preoperative characteristics
Overall, 69 patients underwent OPN (43) or RAPN (26) between Jan
2015–Oct 2018 through the Department of Urology in Christchurch
Hospital and through the Canterbury Urology Associates respectively.
Table 1 shows that there was no significant difference in all baseline
characteristics (age and gender, tumour size, location, histology, and
stage) between the two groups (p < 0.05), except for positive resec-
tion margin. There was a higher number of patients with a positive
resection margin of <1 mm in the OPN group compared with RAPN
(11 vs. 0, respectively, p = 0.0048).
Table 1 Patient demographics and tumour characteristics stratified
according to surgical approach
Table 2 shows that there was no significant difference in estimated
blood loss, warm ischaemic time, operating time, return to theatre,
and number of transfusions for RAPN compared to OPN, respec-
tively. There was significant reduction in mean length of stay how-
ever, for RAPN compared with OPN (2.3 vs. 4.3 days, respectively,
p = 0.0001).
Table 2 Perioperative data comparing open and robotic assisted
partial nephrectomy
Table 3 shows the complications for both groups using the Cla-
vien-Dindo classification system. Overall, there was a reduced num-
ber of complications for RAPN compared with OPN (2 vs. 22, re-
spectively, p = 0.0002). The complications for the OPN group were
mostly grade 1 complications (13), however there were still a signif-
icant number of complications for grade 2a, grade 3, and grade 4
(five, two, and two, respectively) compared with RAPN, whose two
complications were grade 2a.
Table 3 Complications according to the Clavien-Dindo classification
comparing open and robotic assisted partial nephrectomy
Discussion
The robot-assisted approach for partial nephrectomy is currently be-
ing used in many countries, due to being minimally invasive compared
with OPN, with improved view, precision, and ergonomics com-
pared with laparoscopic. 7 This study included 43 OPN patients and
26 RAPN patients, all with similar baseline characteristics (p < 0.05).
As expected, there was a significant reduction in mean length of stay
(2.3 vs. 4.3 days, p = 0.0001) and complications (2 vs. 22, p = 0.0002)
for RAPN compared with OPN, respectively. This is consistent with
current literature, which shows reduced number of complications
and mean length of stay for RAPN. 3–9
The study also showed that two OPN patients required transfusion
compared with no RAPN patients, however this was not statistically
significant (p = 0.523). Two previous studies showed no statistical
difference between groups with regard to blood transfusion require-
ment, which is consistent with this result. 8,10 Several studies including
two meta-analyses showed reduced transfusion requirements for
RAPN compared with OPN. 3–6 The current study may not have had
a large enough sample size to show any statistical significance for an
uncommon outcome such as transfusion, therefore a larger study
may be required to explore this result. This is the limitation of a
retrospective cohort, which requires a large sample size for less common outcomes.
The sample size may explain why we found no statis-
tically significant difference in estimated blood loss between groups,
although there was some missing data for this variable making it less
reliable. Both meta-analyses and the retrospective study by Tan et al
showed less estimated blood loss in the RAPN group compared to
the open group. 3,4,9
The statistical power of this study could have been improved if data
were analysed New Zealand wide, rather than just Canterbury, al-
though this would have required a lot more time and resources.
Recruiting patients that had surgery prior to 2015 would have likely
introduced more missing data, therefore this would not be a good
solution to increasing the sample size.
In our study there were 11 patients with a resection margin of <1 mm
for OPN compared with zero patients for RAPN (p = 0.0048). This
result was consistent with a slightly larger study of 200 patients, 8 but
many studies showed no significant difference in positive resection
margin between RAPN and OPN. 3,7,8,10 It may be worthwhile look-
ing at the way the pathologist reports the positive resection margin,
and whether this has clinical significance. The tumour characteristics
such as location, size, type, and grade were not significantly different
between groups, therefore these factors are unlikely to be acting as
confounding factors. A prospective study that involves a longer fol-
low-up period, looking at oncological outcomes for patients in Can-
terbury would be needed to support this result and improve the level
of evidence. Current literature suggests there is no difference in the
long-term oncological outcomes between OPN and RAPN patients,
although this evidence is limited. 1,2
Other limitations of this study include the inherent differences in pub-
lic compared to private care, including socioeconomic status, waiting
times, and co-morbidities. The private data were also collected by
a different person to the public data, but there was communication
about how this was done to keep it consistent and reduce scope for
error. Operative time for RAPN included anaesthetic time and oc-
casionally other procedures, therefore an estimate was occasionally
required making this result less reliable. Borghesi et al 8 and Tsai et al 4
showed a longer operative time for RAPN compared to OPN, while
other studies showed no difference. 1,3,5,7 This included the meta-anal-
ysis by Xia et al, which showed no association after controlling for
tumour complexity. 3
Better quality evidence is required to limit confounding and selection
bias. Unfortunately, a randomised control trial would not be possible
in Canterbury due to RAPN not being available in the public system,
and this may be considered unethical due to the amount of evidence
showing benefits of RAPN compared with OPN. A prospective study
could be considered in the future for the Canterbury region, to re-
duce bias associated with missing data and to support the current
limited evidence. A longer follow-up period would be beneficial to
compare oncological outcomes, as there is limited evidence looking
at this. Further research could also look at more complex masses
as well as patients with a body mass index of >30, which is a readily
increasing demographic in the population.
In this audit and literature review I have focused on patient factors
for RAPN compared to OPN. Other considerations to justify using
robotic surgery for public cases include benefits of partial nephrec-
tomy over radical nephrectomy, the number of patients per year that
would benefit, as well as overall cost.
In conclusion, this retrospective audit for Canterbury data aligned
with current literature to show that RAPN has a shorter mean length
of stay and lower rate of complications compared with OPN. Inter-
estingly, this study also showed a lower rate of positive resection
margins in the RAPN group, compared with OPN. All other peri-
operative factors and tumour characteristics were similar between
the two groups, including operative time, warm ischaemic time, and
transfusion rates. Further research to increase the level of evidence
would be beneficial, as well as research into the costs involved in
using RAPN for the public health system.
References
1. An JY, Ball MW, Gorin MA, Hong JJ, Johnson MH, Pavlovich CP, et al.
Partial vs radical nephrectomy for T1-T2 renal masses in the elderly:
comparison of complications, renal function, and oncologic outcomes.
Urology [Internet]. 2017 Nov 23 [cited 2019 Jan 3];100:151–7.
Available from: https://doi.org/10.1016/j.urology.2016.10.047
2. Pierorazio PM, Campbell SC. Diagnostic approach, differential
diagnosis, and management of a small renal mass. UpToDate
[Internet]. 2018 Jul [Accessed on 3 January 2019]. Available from:
https://www.uptodate.com/
3. Xia L, Wang X, Xu T, Guzzo TJ. Systematic review and meta-
analysis of comparative studies reporting perioperative outcomes of
robot-assisted partial nephrectomy versus open partial nephrectomy.
J Endourol [Internet]. 2017 Sep 1 [cited 2019 Jan 3];31(9):893–909.
Available from: https://doi.org/10.1089/end.2016.0351
4. Tsai SH, Tseng PT, Sherer BA, Lai YC, Lin PY, Wu CK, et al. Open
versus robotic partial nephrectomy: systematic review and meta-
analysis of contemporary studies. Inte J Med Robot [Internet]. 2018
Sep 28 [cited 2019 Jan 4];0(0):28:e1963. Available from: https://doi.
org/10.1002/rcs.1963
5. Garisto J, Bertolo R, Dagenais J, Sagalovich D, Fareed K, Fergany
A, et al. Robotic versus open partial nephrectomy for highly
complex renal masses: comparison of perioperative, functional,
and oncological outcomes. Urol Oncol [Internet]. 2018 Oct [cited
2019 Jan 3];36(10):471.e1-9. Available from: https://doi.org/10.1016/j.
urolonc.2018.06.012
6. Luciani LG, Chiodini S, Mattevi D, Tommasco C, Puglisi M,
Mantovani W, et al. Robotic-assisted partial nephrectomy provides
better operative outcomes as compared to the laparoscopic and
open approaches: results from a prospective cohort study. J Robot
Surg [Internet]. 2017 Sep [cited 2019 Jan 3];11(3):333–9. Available
from: https://doi.org/10.1007/s11701-016-0660-2
7. Sagalovich D, Dagenais J, Bertolo R, Garisto JD, Kaouk JH. Trifecta
outcomes in renal hilar tumors: a comparison between robotic and
open partial nephrectomy. J Endourol [Internet]. 2018 Sep 12 [cited
2019 Jan 3];32(9):831–6. Available from: https://doi.org/10.1089/
end.2018.0445
8. Borghesi M, Schiavina R, Chessa F, Bianchi L, Manna GL, Porreca A,
et al. Retroperitoneal robot-assisted versus open partial nephrectomy
for cT1 renal tumors: a matched-pair comparison of perioperative
and early oncological outcomes. Clin Genitourin Cancer [Internet].
2018 April [cited 2019 Jan 3];16(2):e391–6. Available from: https://doi.
org/10.1016/j.clgc.2017.09.010
9. Tan JL, Frydenberge M, Grummet J, Hanegbi U, Snow R, Mann S,
et al. Comparison of perioperative, renal and oncologic outcomes
in robotic-assisted versus open partial nephrectomy. ANZ J Surg
[Internet]. 2018 Mar [cited 2019 Jan 4];88(3):E194–9. Available from:
https://doi.org/10.1111/ans.14154
10. Maurice MJ, Ramirez D, Kara O, Malkoc E, Nelson RJ, Fareed K,
et al. Optimum outcome achievement in partial nephrectomy for T1
renal masses: a contemporary analysis of open and robot-assisted
cases. BJU Int [Internet]. 2017 Oct [cited 2019 Jan 3];120(4):537–43.
Available from: https://doi.org/10.1111/bju.13888
11. Dindo D, Demartines N, Clavien PA. Classification of surgical
complications: a new proposal with evaluation in a cohort of 6336
patients and results of a survey. Ann Surg [Internet]. 2004 Aug
[cited 2019 Jan 11];20(2):205–13. Available from: https://dx.doi.
org/10.1097%2F01.sla.0000133083.54934.ae
Correspondence
Lauren Smith: [email protected]
Lauren J Smith
Christchurch School of Medicine
Otago Medical School
University of Otago
Mr Kevin Bax
Urologist at Christchurch Hospital
Clinical Senior Lecturer
University of Otago, Christchurch
Abstract
Robotic assisted partial nephrectomy (RAPN) is not currently of-
fered in the public health system in New Zealand, but current re-
search suggests there may be reduced complications and length of
stay compared to open partial nephrectomy (OPN). The objective
of this study was to retrospectively compare RAPN and OPN ap-
proaches in Canterbury, between Jan 2015–Oct 2018. The study
showed no significant difference in all baseline characteristics be-
tween the two groups (p < 0.05), except positive resection margin,
which showed a higher number with a resection margin (<1 mm for
OPN vs. RAPN; 11 vs. 0, p = 0.0048). There was significant reduc-
tion in mean length of stay for RAPN (2.3 vs. 4.3 days, p = 0.0001)
and number of complications (2 vs. 22, p = 0.0002) compared with
OPN respectively. There was no significant difference in other peri-
operative variables. This study is consistent with current literature,
showing a reduction in length of stay and number of complications for
RAPN compared with OPN, and a lower rate of positive resection
margins. Costs of providing RAPN therefore need to be considered
to determine if there is justification for providing this service in the
public health system. Future research could investigate using a longer
follow-up period to analyse oncological outcomes, such as metastatic
spread and recurrence.
Introduction
Current guidelines suggest removal of small renal masses (<4 cm)
with nephron-sparing surgery when suspicious of malignancy. 1,2 Renal
masses larger than this would impair a large proportion of the kidney,
therefore an inability to preserve its function in nephron-sparing sur-
gery. Nephron-sparing surgery is used to maintain the patient’s kid-
ney function, reducing risk of progression to chronic kidney disease. 1,2
There is no difference in oncological outcomes (local/metastatic
spread and recurrence) with tumours measuring <5 cm, therefore
this is the treatment of choice if technically feasible, unless the tumour
has suggestions of increased oncological potential. 2
There are now many different approaches to nephron-sparing sur-
gery: open, robotic, and laparoscopic. The laparoscopic approach is
not often chosen due to its difficulty for many tumour locations, or
for obese patients who increasingly make up the patient population.
OPN is most often used in the public sector, but RAPN can now be
used as a minimally invasive alternative to OPN in the private sector
of New Zealand with the hope of reducing complications and enhanc-
ing performance. Two meta-analyses showed lower rates of compli-
cations with RAPN, as well as shorter length of stay and reduced
transfusion requirements, compared with the OPN approach. 3,4 Xia
et al carried out sensitivity analysis with exclusion of studies with ob-
vious selection bias with regard to tumour complexity, allowing more
accurate analysis of intra-operative factors. 3 Tsai et al also showed
reduced blood loss for RAPN compared to OPN, particularly in high-
ly complex renal masses, but also a longer operative time. 4 Xia et al
and Tsai et al both had a large sample size, but inherent limitations
involved in observational study. 3,4
A reduction in mean length of stay with RAPN compared with OPN
was demonstrated by several retrospective and prospective studies
carried out since 2016. 5–9 Two retrospective studies also showed a
reduction in intraoperative transfusion rates 5,6 and complications 8,10
with RAPN compared with OPN.
Overall, there is a need for well-designed randomised control trials
with large sample sizes and longer follow-up times, as well as studies
using local data. Robotic surgery is not currently used in the public
health system in Canterbury, therefore it would be useful to analyse
the patient benefit of RAPN compared with OPN using local data. If
local data aligns with current literature showing a significant patient
benefit, then a cost-benefit analysis could be carried out to determine
the feasibility of its use in the Canterbury public health system. For
this reason, a retrospective analysis was carried out comparing RAPN
with OPN using patients in Canterbury. The aim of this study was
to determine if there is any difference between RAPN and OPN in
Canterbury with regard to perioperative variables and complications.
Methods
Study design and data collection
Data from all patients undergoing OPN in the Urology Department
of Christchurch Hospital were retrospectively collected between Jan
2015–Oct 2018. All patients undergoing RAPN by the Urology Asso-
ciates (private urologists in Canterbury) between these dates were
also included. Exclusion criteria were paediatric patients or patients
who were not undergoing tumour removal.
For each patient, we collected data on age, gender, perioperative fac-
tors (operative and ischaemic time, blood loss, peri- and post-opera-
tive complications within 30 days, and hospital stay), and tumour char-
acteristics (tumour size, histotype, stage, and surgical margin status).
Positive resection margin is the margin of surgical tissue that has no no-
table tumour within the resected tissue, determined through histology.
Data was collected through a combination of electronic records and
operative notes, by two different people. Tumour size was deter-
mined using information from histology, and complications were re-
corded according to the Clavien-Dindo classification. 11 This is a classi-
fication system, which grades complications from 1–5, grade 5 being
most severe.
Statistics
Categorical variables were compared using Fisher’s exact two-tailed
test, while continuous variables were compared, calculated using
the unpaired t-test. All statistical analyses were carried out using
Graphpad Prism.
Results
Preoperative characteristics
Overall, 69 patients underwent OPN (43) or RAPN (26) between Jan
2015–Oct 2018 through the Department of Urology in Christchurch
Hospital and through the Canterbury Urology Associates respectively.
Table 1 shows that there was no significant difference in all baseline
characteristics (age and gender, tumour size, location, histology, and
stage) between the two groups (p < 0.05), except for positive resec-
tion margin. There was a higher number of patients with a positive
resection margin of <1 mm in the OPN group compared with RAPN
(11 vs. 0, respectively, p = 0.0048).
Table 1 Patient demographics and tumour characteristics stratified
according to surgical approach
Table 2 shows that there was no significant difference in estimated
blood loss, warm ischaemic time, operating time, return to theatre,
and number of transfusions for RAPN compared to OPN, respec-
tively. There was significant reduction in mean length of stay how-
ever, for RAPN compared with OPN (2.3 vs. 4.3 days, respectively,
p = 0.0001).
Table 2 Perioperative data comparing open and robotic assisted
partial nephrectomy
Table 3 shows the complications for both groups using the Cla-
vien-Dindo classification system. Overall, there was a reduced num-
ber of complications for RAPN compared with OPN (2 vs. 22, re-
spectively, p = 0.0002). The complications for the OPN group were
mostly grade 1 complications (13), however there were still a signif-
icant number of complications for grade 2a, grade 3, and grade 4
(five, two, and two, respectively) compared with RAPN, whose two
complications were grade 2a.
Table 3 Complications according to the Clavien-Dindo classification
comparing open and robotic assisted partial nephrectomy
Discussion
The robot-assisted approach for partial nephrectomy is currently be-
ing used in many countries, due to being minimally invasive compared
with OPN, with improved view, precision, and ergonomics com-
pared with laparoscopic. 7 This study included 43 OPN patients and
26 RAPN patients, all with similar baseline characteristics (p < 0.05).
As expected, there was a significant reduction in mean length of stay
(2.3 vs. 4.3 days, p = 0.0001) and complications (2 vs. 22, p = 0.0002)
for RAPN compared with OPN, respectively. This is consistent with
current literature, which shows reduced number of complications
and mean length of stay for RAPN. 3–9
The study also showed that two OPN patients required transfusion
compared with no RAPN patients, however this was not statistically
significant (p = 0.523). Two previous studies showed no statistical
difference between groups with regard to blood transfusion require-
ment, which is consistent with this result. 8,10 Several studies including
two meta-analyses showed reduced transfusion requirements for
RAPN compared with OPN. 3–6 The current study may not have had
a large enough sample size to show any statistical significance for an
uncommon outcome such as transfusion, therefore a larger study
may be required to explore this result. This is the limitation of a
retrospective cohort, which requires a large sample size for less common outcomes.
The sample size may explain why we found no statis-
tically significant difference in estimated blood loss between groups,
although there was some missing data for this variable making it less
reliable. Both meta-analyses and the retrospective study by Tan et al
showed less estimated blood loss in the RAPN group compared to
the open group. 3,4,9
The statistical power of this study could have been improved if data
were analysed New Zealand wide, rather than just Canterbury, al-
though this would have required a lot more time and resources.
Recruiting patients that had surgery prior to 2015 would have likely
introduced more missing data, therefore this would not be a good
solution to increasing the sample size.
In our study there were 11 patients with a resection margin of <1 mm
for OPN compared with zero patients for RAPN (p = 0.0048). This
result was consistent with a slightly larger study of 200 patients, 8 but
many studies showed no significant difference in positive resection
margin between RAPN and OPN. 3,7,8,10 It may be worthwhile look-
ing at the way the pathologist reports the positive resection margin,
and whether this has clinical significance. The tumour characteristics
such as location, size, type, and grade were not significantly different
between groups, therefore these factors are unlikely to be acting as
confounding factors. A prospective study that involves a longer fol-
low-up period, looking at oncological outcomes for patients in Can-
terbury would be needed to support this result and improve the level
of evidence. Current literature suggests there is no difference in the
long-term oncological outcomes between OPN and RAPN patients,
although this evidence is limited. 1,2
Other limitations of this study include the inherent differences in pub-
lic compared to private care, including socioeconomic status, waiting
times, and co-morbidities. The private data were also collected by
a different person to the public data, but there was communication
about how this was done to keep it consistent and reduce scope for
error. Operative time for RAPN included anaesthetic time and oc-
casionally other procedures, therefore an estimate was occasionally
required making this result less reliable. Borghesi et al 8 and Tsai et al 4
showed a longer operative time for RAPN compared to OPN, while
other studies showed no difference. 1,3,5,7 This included the meta-anal-
ysis by Xia et al, which showed no association after controlling for
tumour complexity. 3
Better quality evidence is required to limit confounding and selection
bias. Unfortunately, a randomised control trial would not be possible
in Canterbury due to RAPN not being available in the public system,
and this may be considered unethical due to the amount of evidence
showing benefits of RAPN compared with OPN. A prospective study
could be considered in the future for the Canterbury region, to re-
duce bias associated with missing data and to support the current
limited evidence. A longer follow-up period would be beneficial to
compare oncological outcomes, as there is limited evidence looking
at this. Further research could also look at more complex masses
as well as patients with a body mass index of >30, which is a readily
increasing demographic in the population.
In this audit and literature review I have focused on patient factors
for RAPN compared to OPN. Other considerations to justify using
robotic surgery for public cases include benefits of partial nephrec-
tomy over radical nephrectomy, the number of patients per year that
would benefit, as well as overall cost.
In conclusion, this retrospective audit for Canterbury data aligned
with current literature to show that RAPN has a shorter mean length
of stay and lower rate of complications compared with OPN. Inter-
estingly, this study also showed a lower rate of positive resection
margins in the RAPN group, compared with OPN. All other peri-
operative factors and tumour characteristics were similar between
the two groups, including operative time, warm ischaemic time, and
transfusion rates. Further research to increase the level of evidence
would be beneficial, as well as research into the costs involved in
using RAPN for the public health system.
References
1. An JY, Ball MW, Gorin MA, Hong JJ, Johnson MH, Pavlovich CP, et al.
Partial vs radical nephrectomy for T1-T2 renal masses in the elderly:
comparison of complications, renal function, and oncologic outcomes.
Urology [Internet]. 2017 Nov 23 [cited 2019 Jan 3];100:151–7.
Available from: https://doi.org/10.1016/j.urology.2016.10.047
2. Pierorazio PM, Campbell SC. Diagnostic approach, differential
diagnosis, and management of a small renal mass. UpToDate
[Internet]. 2018 Jul [Accessed on 3 January 2019]. Available from:
https://www.uptodate.com/
3. Xia L, Wang X, Xu T, Guzzo TJ. Systematic review and meta-
analysis of comparative studies reporting perioperative outcomes of
robot-assisted partial nephrectomy versus open partial nephrectomy.
J Endourol [Internet]. 2017 Sep 1 [cited 2019 Jan 3];31(9):893–909.
Available from: https://doi.org/10.1089/end.2016.0351
4. Tsai SH, Tseng PT, Sherer BA, Lai YC, Lin PY, Wu CK, et al. Open
versus robotic partial nephrectomy: systematic review and meta-
analysis of contemporary studies. Inte J Med Robot [Internet]. 2018
Sep 28 [cited 2019 Jan 4];0(0):28:e1963. Available from: https://doi.
org/10.1002/rcs.1963
5. Garisto J, Bertolo R, Dagenais J, Sagalovich D, Fareed K, Fergany
A, et al. Robotic versus open partial nephrectomy for highly
complex renal masses: comparison of perioperative, functional,
and oncological outcomes. Urol Oncol [Internet]. 2018 Oct [cited
2019 Jan 3];36(10):471.e1-9. Available from: https://doi.org/10.1016/j.
urolonc.2018.06.012
6. Luciani LG, Chiodini S, Mattevi D, Tommasco C, Puglisi M,
Mantovani W, et al. Robotic-assisted partial nephrectomy provides
better operative outcomes as compared to the laparoscopic and
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Correspondence
Lauren Smith: [email protected]
