Outcomes of robotic-assisted radical nephrectomy during service implementation: Lessons from an audit

Abstract

Background

Robot-assisted surgery (RAS) is an extension of minimally invasive surgery rapidly gaining acceptance in many conditions. The study aims to assess and share lessons impact of RAS on the radical nephrectomy (RN) service during the implementation phase.

Methods

Two separate analyses were carried out: to compare the outcome of all RN – before and after the implementation of RAS regardless of surgical mode, and a direct comparison between two minimal invasive approaches: Robotic-assisted radical nephrectomies (RARNs) and Laparoscopic radical nephrectomies (LRNs).

Results

The study included 55 pre- and 45 robotic era RNs: 45 RARNs, 48 LRNs and 7 open radical nephrectomies (ORNs). Following RAS implementation, all RNs transitioned to RARNs. The broader comparison of all RNs in the robotic versus pre-robotic periods revealed significant reductions in estimated blood loss and the length of hospital stay, though operative times were notably longer. In the direct comparison between LRNs and RARNs, no major differences in perioperative outcomes were noted, except for a significantly longer duration of surgery in the RARN group.

Conclusion

The introduction of the robotic platform resulted in a paradigm shift in RN service, eliminating ORN and LRN. Despite increasing operative duration, RARNs improved certain perioperative outcomes (specifically length of stay and blood loss) and were favoured over other modalities.

Keywords

Renal cell carcinoma robot-assisted radical nephrectomy laparoscopic radical nephrectomy robotic surgery

Background

Renal cell carcinoma (RCC) ranks high amongst the prevalent urological malignancies, contributing to approximately 13,300 new cases annually in the UK.¹ Radical nephrectomy (RN) remains the primary treatment for renal masses indicative of RCC, which are unsuitable for nephron-sparing approaches.² Traditionally performed via open surgery (open radical nephrectomy [ORN]), the evolution of minimally invasive surgery has seen a paradigm shift. Laparoscopic RN (LRN) and, more recently, robot-assisted RN (RARN) are now the most common surgical techniques practised the world over.³

Minimally invasive approaches, especially LRN, have been widely adopted due to their benefits over ORN, including reduced blood loss, shorter hospital stays and quicker recovery while maintaining oncological efficacy.^4–6 However, despite its advantages, LRN comes with limitations such as restricted manoeuvrability and two-dimensional visual feedback, which can pose challenges in complex surgical scenarios.

The advent of robot-assisted surgery (RAS) introduces enhanced three-dimensional visualisation, superior precision and greater dexterity, theoretically overcoming many limitations of conventional laparoscopy. Robot-assisted surgery offers articulated instruments and ergonomic advantages, potentially reducing surgeon fatigue and facilitating complex manoeuvres during nephrectomies.⁷

Despite these technological advancements, existing studies have not conclusively shown superior perioperative outcomes for RARN compared to LRN, with RARN often entailing longer operative durations and elevated costs.^7–11 However, the current trends show a growing preference for robotic approaches, reflected in the increasing number of RARNs performed globally. The reason for this shift remains unclear and probably is multifactorial: the potential for better surgical outcomes, surgeons’ preference due to better ergonomics and the economic demand of surgical units to perform a minimal number of procedures annually to offset the upfront and ongoing costs of its acquisition.^7–9 An additional important factor is the ability of RAS to offer a minimally invasive approach for cases where LRN may not be technically feasible, as an alternative major open abdominal surgery.¹²

Although RAS has been widely adopted in urological institutions,¹³ it is unclear how deploying RAS will affect already-established RN services.

Given the paucity of literature in this area and variation in outcomes reporting of RARN and LRN, we aimed to provide a comprehensive audit and analysis of the implementation of RAS at a district general hospital (DGH) RN service, offering insights into its impacts on surgical outcomes and procedural choices in the treatment of RCC.

We hypothesise that RARN may decrease the frequency of open interventions and enhance overall perioperative outcomes for radical nephrectomies.

Methodology

The data was collected from Lincoln Teaching Hospital, the only hospital in United Lincolnshire Teaching Hospitals NHS Trust (ULTHT) with a Robotic surgical platform. The ULTHT serves over 750,000 people. The retrospective data was extracted from patient notes and hospital electronic records.

In this retrospective analysis, radical nephrectomies undertaken over one year (1 February 2022 to 1 February 2023) immediately following the adoption of an RAS were evaluated and compared with a similar pre-implementation period (1 January 2018 to 1 January 2019). This specific pre-RAS time frame was selected to mitigate the impact of COVID-19 on surgical services.

Inclusion criteria encompassed all patients who underwent RN (RARN, non-robotic LRN or ORN) within the study periods. Some patients with T1 tumours, not amenable to nephron-sparing surgery due to unfavourable (central/hillier) location of growth, also included in this group. The patients considered for nephron-sparing surgery or tumour thrombus above the renal vein level requiring complex intervention were referred to tertiary centres following the centralisation policy.

Simple nephrectomy and nephroureterectomy cases were excluded. This exclusion allowed focus on quantifiable renal pathologies with more uniform characteristics, such as tumour size and location, thereby facilitating a more equitable comparison.

The first RARN was performed in our institution on 1 February 2022, which is considered the RAS implementation date. The robotic platform utilised in Lincoln Teaching Hospital is Da Vinci Xi from Intuitive. To structure analysis, patients were categorised into four groups, organised by surgical modality and era (pre- or post-RAS).

Group I: All RN cases post RAS era, 1 February 2022–1 February 2023

Group II: Includes RARN cases only in post RAS era, 1 February 2022–1 February 2023

Group III: All RN cases pre-RAS era, 1 January 2018–1 January2019

Group IV: LRN cases only in pre-RAS era, 1 January 2018–1 January 2019

To prevent case fragmentation, LRNs, whether hand-assisted or pure laparoscopic in approach, were considered as a single group. This method of analysis is supported by evidence indicating similar perioperative outcomes for both minimally invasive techniques.^15–17

The following group of parameters were recorded: patient demographics, tumour characteristics and perioperative outcome variables. Patient demographics were age, gender and American Society of Anaesthesiologists (ASA) grade. Tumour characteristics comprised of size and pathological stage. Outcome variables include: operative time, estimated blood loss, conversion rate, intra-operative and postoperative complications, perioperative transfusion rate, 30-day readmission rate and length of inpatient stay. Operative time was calculated from incision to the closure of all surgical wounds. Complications were graded using the Clavien-Dindo system,¹⁸ and all Grade 2 and above complications were included in this analysis.

The study's primary outcome was comparing the recorded perioperative outcome variables of all RN cases (irrespective of the surgical modality) before and after the implementation of the robotic service. This correlates with a comparison between groups I and III.

The secondary outcome of the study was the comparison of the same recorded parameters between two minimally invasive approaches: LRN and RARN. This correlates with a comparison between groups II and IV.

Statistical analyses were carried out using IBM SPSS 20 statistical software. Chi-squared analysis or Fisher's exact test was used for categorical variables, where appropriate. Mann–Whitney U tests and paired sample t-tests were utilised for continuous variables, per data distribution patterns. A p value of <0.05 was considered statistically significant. All patient data were anonymised during statistical analysis.

Results

Firstly, the total number of radical nephrectomies and their surgical modality were evaluated. Prior to the implementation of RAS, 55 radical nephrectomies were performed: 48 LRNs (hand-assisted or standard laparoscopic) and 7 ORNs. For LRNs before the introduction of the RAS, two of the three upper tract surgeons in the DGH utilised a hand-assisted approach, and one utilised a standard laparoscopic approach. After the implementation of the RAS, our centre ceased performing open or non-robotic LRNs. Between 1 February 2022 and 1 February 2023, 45 radical nephrectomies were performed; all 45 were RARNs. As no non-robotic LRNs or ORNs were performed in the DGH after the implementation of the RAS, groups I and II are interchangeable.

The results comparing parameters for all RNs before (Group III) and after (Group I) the implementation of the RAS are illustrated in Table 1. No significant demographic differences were observed in means of age, gender or ASA grade. No significant differences were also demonstrated in terms of tumour size between the two groups and the distribution of pathological staging. Analysis revealed significant improvements in both estimated blood loss in mls (164.77 ± 52 vs 238.18 ± 50.46; p = 0.037) and length of stay in days (4 ± 0.77 vs 6.61 ± 2.3 days; p = 0.039) for RNs after robotic implementation, though the operative time in minutes was longer in this group (186.42 ± 12.3 vs 153.1 ± 10; p < 0.001). No significant differences were observed in other parameters, such as the rates of transfusions, conversions, intra- or post-operative complications or readmission.

Table 1.

Patient demographics, tumour characteristics and peri-operative outcomes for Group I and Group III.

			Group I	Group III	p value
Demographics	Number of patients		45	55
	Age		67.68 ± 3.26	64.5 ± 2.75	0.28
	ASA grade		2.37 ± 0.147	2.12 ± 0.2	0.6
	Male (n, %)		29 (64.4)	38 (69)	0.21
Tumour Characteristics	Maximum diameter		6.93 ± 0.9	7.74 ± 0.93	0.2
	Pathological stage (n, %)	pT1a	4 (8.9)	4 (7.2)	0.05
		pT1b	12 (26)	14 (25.4)	0.81
		pT2a	5 (11)	5 (9.1)	0.73
		pT2b	3 (6.6)	5 (9.1)	0.65
		pT3a	14 (31)	22 (40)	0.1
		Benign	7 (15.5)	5 (9.1)	0.32
Perioperative Variables	Operative time (min)		186.42 ± 12.3	153.1 ± 10	<0.001
	Estimated blood loss (ml)		164.77 ± 52	238.18 ± 50.46	0.037
	Conversion rate (n, %)		1 (2.2)	1 (1.8)	0.88
	Transfusion rate (n, %)		3 (6.6)	5 (9%)	0.65
	Intra-operative complications		5 (11)	5 (9)	0.73
	Post-operative complications Grade II and above (n, %)		6 (13.3)	12 (21)	0.27
	Readmission rate (n, %)		2 (4.4)	3 (5.4)	0.81
	Length of stay (days)		4 ± 0.77	6.61 ± 2.3	0.039

The results related to the secondary outcome are illustrated in Table 2, comparing two minimally invasive approaches: RARNs (Group II) versus LRNs (Group IV). Again no significant differences were observed regarding patient demographics or tumour characteristics. The analysis confirmed increased operative time in minutes for RARNs when compared to LRNs prior to robot utilisation (186.42 ± 12.3 vs 154.4 ± 8.9; p < 0.001). No significant differences were observed in other parameters, such the blood loss, length of stay, rates of transfusions, conversions, intra- or post-operative complications or readmission.

Table 2.

Patient demographics, tumour characteristics and peri-operative outcomes for Group II and Group IV.

			Group II	Group IV	p value
Demographics	Number of patients		45	48
	Age		67.68 ± 3.26	65.02 ± 3.07	0.28
	ASA grade		2.37 ± 0.147	2.08 ± 0.22	0.42
	Male (n, %)		29 (64.4)	32 (66.6)	0.17
Tumour Characteristics	Maximum diameter cm		6.93 ± 0.9	7.08 ± 0.81	0.78
	Pathological stage (n, %)	pT1a	4 (8.9)	3 (6.25)	0.63
		pT1b	12 (26)	12(25)	0.8
		pT2a	5 (11)	5 (10.4)	0.91
		pT2b	3 (6.6)	5 (10.4)	0.51
		pT3a	14 (31)	20(35.4)	0.09
		Benign	7 (15.5)	3 (6.25)	0.21
Perioperative Variables	Operative time (min)		186.42 ± 12.3	154.4 ± 8.9	<0.001
	Estimated blood loss (ml)		164.77 ± 52	221.87 ± 51.8	0.1
	Conversion rate (n, %)		1 (2.2)	1 (1.8)	0.96
	Transfusion rate (n, %)		3 (6.6)	4 (8.3)	0.76
	Intra-operative complications		5 (11)	5 (10.4)	0.91
	Post-operative complications Grade II and above (n, %)		6 (13.3)	9 (18.75)	0.47
	Readmission rate (n, %)		2 (4.4)	3 (6.25)	0.7
	Length of stay (days)		4 ± 0.77	5.8 ± 2.39	0.15

In the pre-RAS era, seven ORNs were conducted. In five of these cases, an open approach was favoured by the surgeons due to the presence of large tumours (>12 cm) predominantly located in the mid or upper renal pole. One case involved cytoreductive nephrectomy following tyrosine kinase inhibitor (TKI) therapy, where a minimally invasive approach (laparoscopic RN) was not feasible due to extensive desmoplastic adhesions. Another case required open surgery because of complex prior abdominal issues, specifically extensive adhesions resulting from open caecal cancer resection. In the robotic era, five cases were encountered with large upper/midpole tumours (>12 cm). The availability of RAS allowed us to avoid open intervention in all cases.

In the post-robotic era, no nephrectomy procedures required open access. Within each group, a single case presented with a Grade IIIb complication as per the Clavien-Dindo classification, necessitating laparotomy in the post-operative period due to bleeding. All remaining complications were Grade II in severity.

Discussion

The utilisation of minimally invasive approaches (LRN and RARN) in RN procedures has been firmly established in surgical practice. However, the specific advantages of robot-assisted techniques over traditional laparoscopic methods remain a topic of ongoing investigation and debate. In this discussion, we delve into several key studies that compare these approaches, offering insights into their respective benefits and limitations. Our study focused on the impact of introducing a robotic platform into a DGH's RN service, analysing both the outcomes of surgery and the likelihood of patients undergoing minimally invasive procedures versus open RNs.

After the implementation of RAS, our unit, for RN cases started exclusively to utilise Robotic assistance instead of conventional or hand-assisted laparoscopy. The short learning curve of RAS facilitated this transition without compromising patient safety and outcomes. Two of three upper tract surgeons without previous robotic experience, after short induction and mentorship, prefer the RAS over the laparoscopy for its finer manipulations, greater range of motions, 3-D vision and the presence of the fourth robotic arm which provides upward retraction of the kidney.

This is aligned with the findings from a large cohort study in the USA on this topic, which notes a steady increase in RARNs to ∼30% of all RNs by 2015 alongside a concurrent reduction in LRNs,¹⁰ strengthening the generalisability of our results to the broader urological landscape. These findings are further externally validated by data from a large cohort study and BAUS nephrectomy audit^3,10 showing the steadily increasing role of RARN in the management of RCC.

The significantly reduced number (more specifically, the total absence) of ORNs post-implementation supports the hypothesis that the availability of a robotic platform facilitates the transition away from ORNs. Our analysis shows the indications for open intervention in pre-RAS period were mainly large (>12 cm) upper/mid-pole lesions. Despite there is no difference in terms of the tumour characteristics (size, pathological grade) between the patient groups before and after RAS implementation, there is no open intervention in RAS era. So the availability of RAS eliminates the necessity of open interventions in that category of patients. This aligned with the largest multicentre comparison of RARN and LRN, highlighting that RARN is being performed in more challenging cases where LRN may not be technically feasible. In many cases, the alternative is major open abdominal surgery, compared to which RARN consistently provides benefits of reduced blood loss, pain, opiate consumption, length of stay and overall recovery time.^12,14

Of course, having RAS available does not mean that open interventions, which are often reserved for patients with the most complexity, are no longer necessary.¹⁹

The shift towards minimally invasive procedures, also observed in our study, has been deemed positive by substantial existing literature demonstrating favourable outcomes and safety profiles associated with laparoscopic and robotic-assisted approaches when compared to ORNs.^10,20,21 In this study, analysis of overall RN outcomes corroborated this, with RN patients benefiting from improvements in estimated blood loss and length of stay after the introduction of the robot. However, these benefits were noted only when RARNs were compared to LRNs and ORNs and were not replicated during direct comparison between RARNs and LRNs. Thus, it is evident, that these advantages are likely due to the increased proportion of minimally invasive RNs (and reduction in ORNs), rather than the robotic assistance itself.⁹

Despite a growing preference for RARNs, there is notable contention regarding their merit when compared to LRNs. Alongside RARNs demonstrating no specific benefits when directly compared to LRNs in this study, further analysis of the data revealed comparable perioperative outcomes for both methods: there were no significant differences in length of stay, estimated blood loss or rates of transfusion, conversion or intra- and post-operative complications.²² Findings suggesting the limited specific benefit of RARN over LRN and difficulties with increased operative time are supported by numerous studies,^{7,10,20,21,23,24} including a systemic review and meta-analysis by Li et al. and Crocerossa et al.^9,24 Our data concurs that operative time was significantly increased by RAS, in comparison to both LRNs alone and all RNs before the introduction of the robot. Though this increase in operative time did not appear anecdotally to significantly impact theatre list utilisation, further investigation into potential impacts on caseload and waiting lists may be required, as highlighted by Shinder et al. in an (albeit hypothetical) projection on robotic urology bottlenecks.²⁵ Robotic-assisted radical nephrectomies are generally considered to have a significantly increased duration than non-robotic LRNs, with the aforementioned comprehensive retrospective cohort study by Jeong et al. demonstrating prolonged operating times (exceeding 4 h) and increased costs.¹⁰ On the other hand, several studies have reported no significant difference between operating time in RARNs versus LRNs.^9,26,27 This may be explained by the fact that these studies with longer operative time investigated very early RRN cases and may have been influenced by the learning curve not only of robotic surgeons but also by theatre staff. Contrarily, the studies including data sets of cases performed by surgeons experienced in robotic surgery showed no significant difference in operative time between robotic and laparoscopic RN cases. This agrees with our observations, as within our upper tract surgeons performing RAS, the difference in operating time between an experienced robotic surgeon and a novel surgeon within their early learning curve, was well noticeable. It makes sense, that in services where RAS is well established, there would be a shift of the noted difference in means of operating time, favouring RAS.

Complications are an important parameter for estimating the safety of surgical techniques. This is specifically important during the implementation of new surgical modalities already well-established services. Our study suggested that RARN had a similar rate of intra-operative and post-operative complications as those of LRN. This is an important finding, considering that we compare a RAS within its first year of implementation, with a well-established LRN service. In addition, as discussed previously, our RAS cases included some complex cases, which in the past would not have been attempted with a minimally invasive approach. This is supported by other studies involving significantly larger cohorts.^7,9,10,11 Other studies observed a lower complication rate in robotic arms compared to laparoscopy.^22,²⁸ Only one major complication (Grade III b) was observed in each group. Remaining complications were Grade II only.

Limitations

To the best of our knowledge, our study is the first to examine the impact of introducing a robotic platform on RN services, with strengths in its comprehensive data collection process, strategic categorisation and methodological approach minimising confounding factors. However, it is crucial to acknowledge potential limitations. The initial year post-implementation, which is the focus of our study, represents a period where there was a mixture of an experienced robotic surgeon, and upper tract surgeons, previously adept in pure/hand-assisted laparoscopic and open surgeries, now adapting the RAS. This might have influenced certain perioperative outcomes. Additionally, we did not investigate the financial impact of the introduction of RAS in RN services. Finally, longer-term outcomes and trends associated with the implementation of the robotic service are not captured by a retrospective study over one-year time frames; a more comprehensive appreciation of the sustained impact would require longitudinal studies.

Conclusion

In conclusion, the introduction of a robotic platform in a DGH transformed the RN service, resulting in the exclusive adoption of RARN and the elimination of LRN and ORN. Our data suggests that while RARN did not show a marked advantage over LRN in direct comparisons, its implementation has facilitated a shift towards minimally invasive surgery, with evident positive impacts for RN patients regarding estimated blood loss and hospital stays. The results of this study contribute valuable insights into the practical consequences of robotic technology integration in urological oncology and underscore the importance of ongoing evaluation of surgical approaches in RNs to ensure optimised patient outcomes.

Recommendations for Further Research

Evaluate the impact of increased operative time on theatre list utilisation quantitatively, and the impact on perceived caseload qualitatively.

To assess the financial impact of implementation of RAS in RN service.

Footnotes

Acknowledgements

The authors thank Oluwatobi Olaniyi and Haris Ullah for their significant contribution to data collection.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Samvel Nikoghosyan

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