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Robotic partial nephrectomy may be superior to open, laparoscopic procedures

Photo of Inderbir S. Gill 2018
Inderbir S. Gill

Robotic partial nephrectomy appeared associated with predominantly superior outcomes compared with open or laparoscopic partial nephrectomy, according to results of a meta-analysis.

Inderbir S. Gill, MD, chair and distinguished professor of urology at Keck School of Medicine of USC, and colleagues, used the PubMed, Scopus and Web of Science databases to review data from 20,282 patients who underwent partial nephrectomy between Jan. 1, 2000, and June 2017.

Robotic procedures appeared superior to open procedures for a number of parameters, including blood loss (weighted mean difference, 85.01; P < .00001), transfusions (OR = 1.81; P < .001), complications (OR = 1.87; P < .00001), hospital stay (weighted mean difference, 2.26; P = .001), readmissions (OR = 2.58; P = .005), percentage reduction of latest estimated glomerular filtration rate (weighted mean difference, 0.37; P = .04), overall mortality (OR = 4.45; P < .0001) and recurrence rate (OR = 5.14; P < .00001).

For the comparison between robotic and laparoscopic partial nephrectomy, robotic procedures showed superiority in terms of ischemia time (weighted mean difference, 4.21; P < .0001), conversion rate (OR = 2.61; P = .002), intraoperative complications (OR = 2.05; P > .0001), postoperative complications (OR = 1.27; P = .0003), positive margins (OR = 2.01; P < .0001), percentage decrease of latest estimated glomerular filtration rate (weighted mean difference, – 1.97; P = .02) and overall mortality (OR = 2.98; P = .04).

HemOnc Today spoke with Gill about the rationale for the study, as well as the implications of the results.

 

Question: Can you provide an overview of the study rationale, including the need to determine which approach is optimal?

Answer: If someone were to ask me how open, robotic and laparoscopic partial nephrectomy compare in terms of surgical margin rates, blood loss, kidney function or complications, it would be difficult to give a clear, unbiased answer. For every paper you can cite with data showing robotics is better for any of these outcomes, another person could show you a different paper that demonstrates the opposite. Because level one prospective randomized data for open versus robotic partial nephrectomy are not available, it is difficult to distill the available data in a meaningful and unbiased way to advise and guide patients. Most available studies on this topic are retrospective, with inherent institutional or surgeon bias, so it is difficult to place complete faith in any one paper. Absent level one evidence, the next-best scenario is a systematic review and meta-analysis of the entire literature on partial nephrectomy, with sensitivity analysis. Our paper attempts to provide the highest level of evidence short of a prospective randomized trial. We believe these data can be used in daily clinical practice to have a more accurate discussion of surgical options with patients considering partial nephrectomy.

 

Q: How did you conduct the study?

A: Our team — including first author Giovanni Cacciamani, MD, research fellow in the department of urology at USC — systematically searched the literature from 2000 to 2017 for the term “partial nephrectomy.” That gave us more than 12,000 papers. We narrowed them down to about 100 papers that compared robotic partial nephrectomy with open or laparoscopic partial nephrectomy. We studied each one in detail, analyzing every data point. We then performed rigorous statistical analysis to address key questions.

 

 

Q: What did you find?

A: The available data in the literature indicate that, for various outcomes, robotic partial nephrectomy appears to be superior to open partial nephrectomy. After sensitivity analysis of papers reporting kidney tumors of similar complexity, robotic partial nephrectomy was superior to open surgery with regard to blood loss, transfusions, complications, hospital stay and kidney function preservation; however, operative time, warm ischemia time and positive margin rates were similar between robotic and open surgery. When using sensitivity analyses to look only at complex kidney tumors, robotic surgery remained superior to open surgery for blood loss, complications and hospital stay. Other parameters were similar between groups. Robotic partial nephrectomy was generally superior to laparoscopic surgery. Based on the available literature, our meta-analysis indicates that robotic partial nephrectomy has now emerged as a safe, effective and even preferred approach for partial nephrectomy for patients with small renal masses.

 

Q: What did you find in terms of safety and costs?

A: Complications, meaning bad outcomes, were fewer in the robotic arm. We did not specifically evaluate cost. We are working on another paper about the impact of robotics in the field of urologic cancer surgery. Those results indicate costs were uniformly higher with robotic surgery.

 

Q: Are there any limitations of your paper?

A: One must realize the value of any meta-analysis fundamentally depends upon the level of evidence in the peer-reviewed literature that goes into that meta-analysis. The poorer the quality of the literature, the less reliable the meta-analysis. For a meta-analysis to be rigorous, it must also include sensitivity analyses, where you correct for baseline differences among groups. For example, the meta-analysis might show robotic partial nephrectomy has less blood loss than open surgery, but if the tumors in the robotic group were considerably smaller than those in the open group, it’s not an accurate comparison. In our paper, we performed the necessary sensitivity analyses to correct for important baseline differences, thereby comparing apples to apples to the extent possible. It is important to note that no level one prospective randomized data for robotic partial nephrectomy have been published. Our analysis revealed that 95% of the published papers provided level three or level four evidence. This remains a major limitation. The data may be limited and have flaws, but they are all we have.

 

Q: Where does that leave us?

A: The pendulum has now swung significantly in favor of robotic partial nephrectomy, which comprises more than 66% of all partial nephrectomies in the United States, up from only 0.6% in 2005. – by Rob Volansky

 

Reference:

Cacciamani GE, et al. J Urol. 2018;doi:10.1016/j.juro.2017.12.086.

For more information:

Inderbir Gill, MD, can be reached at Keck School of Medicine of USC, 1975 Zonal Ave., Los Angeles, CA 90033; email: cynthia.smith@med.usc.edu.

Disclosure: Gill reports no relevant financial disclosures.

Photo of Inderbir S. Gill 2018
Inderbir S. Gill

Robotic partial nephrectomy appeared associated with predominantly superior outcomes compared with open or laparoscopic partial nephrectomy, according to results of a meta-analysis.

Inderbir S. Gill, MD, chair and distinguished professor of urology at Keck School of Medicine of USC, and colleagues, used the PubMed, Scopus and Web of Science databases to review data from 20,282 patients who underwent partial nephrectomy between Jan. 1, 2000, and June 2017.

Robotic procedures appeared superior to open procedures for a number of parameters, including blood loss (weighted mean difference, 85.01; P < .00001), transfusions (OR = 1.81; P < .001), complications (OR = 1.87; P < .00001), hospital stay (weighted mean difference, 2.26; P = .001), readmissions (OR = 2.58; P = .005), percentage reduction of latest estimated glomerular filtration rate (weighted mean difference, 0.37; P = .04), overall mortality (OR = 4.45; P < .0001) and recurrence rate (OR = 5.14; P < .00001).

For the comparison between robotic and laparoscopic partial nephrectomy, robotic procedures showed superiority in terms of ischemia time (weighted mean difference, 4.21; P < .0001), conversion rate (OR = 2.61; P = .002), intraoperative complications (OR = 2.05; P > .0001), postoperative complications (OR = 1.27; P = .0003), positive margins (OR = 2.01; P < .0001), percentage decrease of latest estimated glomerular filtration rate (weighted mean difference, – 1.97; P = .02) and overall mortality (OR = 2.98; P = .04).

HemOnc Today spoke with Gill about the rationale for the study, as well as the implications of the results.

 

Question: Can you provide an overview of the study rationale, including the need to determine which approach is optimal?

Answer: If someone were to ask me how open, robotic and laparoscopic partial nephrectomy compare in terms of surgical margin rates, blood loss, kidney function or complications, it would be difficult to give a clear, unbiased answer. For every paper you can cite with data showing robotics is better for any of these outcomes, another person could show you a different paper that demonstrates the opposite. Because level one prospective randomized data for open versus robotic partial nephrectomy are not available, it is difficult to distill the available data in a meaningful and unbiased way to advise and guide patients. Most available studies on this topic are retrospective, with inherent institutional or surgeon bias, so it is difficult to place complete faith in any one paper. Absent level one evidence, the next-best scenario is a systematic review and meta-analysis of the entire literature on partial nephrectomy, with sensitivity analysis. Our paper attempts to provide the highest level of evidence short of a prospective randomized trial. We believe these data can be used in daily clinical practice to have a more accurate discussion of surgical options with patients considering partial nephrectomy.

 

Q: How did you conduct the study?

A: Our team — including first author Giovanni Cacciamani, MD, research fellow in the department of urology at USC — systematically searched the literature from 2000 to 2017 for the term “partial nephrectomy.” That gave us more than 12,000 papers. We narrowed them down to about 100 papers that compared robotic partial nephrectomy with open or laparoscopic partial nephrectomy. We studied each one in detail, analyzing every data point. We then performed rigorous statistical analysis to address key questions.

 

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Q: What did you find?

A: The available data in the literature indicate that, for various outcomes, robotic partial nephrectomy appears to be superior to open partial nephrectomy. After sensitivity analysis of papers reporting kidney tumors of similar complexity, robotic partial nephrectomy was superior to open surgery with regard to blood loss, transfusions, complications, hospital stay and kidney function preservation; however, operative time, warm ischemia time and positive margin rates were similar between robotic and open surgery. When using sensitivity analyses to look only at complex kidney tumors, robotic surgery remained superior to open surgery for blood loss, complications and hospital stay. Other parameters were similar between groups. Robotic partial nephrectomy was generally superior to laparoscopic surgery. Based on the available literature, our meta-analysis indicates that robotic partial nephrectomy has now emerged as a safe, effective and even preferred approach for partial nephrectomy for patients with small renal masses.

 

Q: What did you find in terms of safety and costs?

A: Complications, meaning bad outcomes, were fewer in the robotic arm. We did not specifically evaluate cost. We are working on another paper about the impact of robotics in the field of urologic cancer surgery. Those results indicate costs were uniformly higher with robotic surgery.

 

Q: Are there any limitations of your paper?

A: One must realize the value of any meta-analysis fundamentally depends upon the level of evidence in the peer-reviewed literature that goes into that meta-analysis. The poorer the quality of the literature, the less reliable the meta-analysis. For a meta-analysis to be rigorous, it must also include sensitivity analyses, where you correct for baseline differences among groups. For example, the meta-analysis might show robotic partial nephrectomy has less blood loss than open surgery, but if the tumors in the robotic group were considerably smaller than those in the open group, it’s not an accurate comparison. In our paper, we performed the necessary sensitivity analyses to correct for important baseline differences, thereby comparing apples to apples to the extent possible. It is important to note that no level one prospective randomized data for robotic partial nephrectomy have been published. Our analysis revealed that 95% of the published papers provided level three or level four evidence. This remains a major limitation. The data may be limited and have flaws, but they are all we have.

 

Q: Where does that leave us?

A: The pendulum has now swung significantly in favor of robotic partial nephrectomy, which comprises more than 66% of all partial nephrectomies in the United States, up from only 0.6% in 2005. – by Rob Volansky

 

Reference:

Cacciamani GE, et al. J Urol. 2018;doi:10.1016/j.juro.2017.12.086.

For more information:

Inderbir Gill, MD, can be reached at Keck School of Medicine of USC, 1975 Zonal Ave., Los Angeles, CA 90033; email: cynthia.smith@med.usc.edu.

Disclosure: Gill reports no relevant financial disclosures.