Robotic nephrectomy for inferior vena cava tumor thrombus has favorable outcomes and reproducibility when performed by surgeons with adequate robotic experience, according to first multi-institutional report, published in the journal of urology
New York, NY, Feb. 7, 2016 – Renal cell carcinoma can sometimes spread to the inferior vena cava (IVC), the body’s largest vein, posing a threat to the heart and brain. Robotic nephrectomy for inferior vena cava tumor thrombus has favorable outcomes in selected patients compared with open surgery, which can have a high rate of complications, report surgeons in The Journal of Urology®.
Renal vein surgery can often be managed with minimally invasive laparoscopic techniques, but this is not typically advisable for an IVC thrombus (a fibrous clot), which is surgically far more complex with potentially fatal complications that can occur in the course of removing the thrombus and reconstructing the IVC.
The first known procedure using robotic surgery of renal tumors with IVC tumor thrombi was performed in 2008. Experts from nine leading U.S. medical centers report here on their combined experience of 32 cases since 2008. Each surgeon performed between one and ten procedures for IVC tumor thrombi which ranged from one to 11 cm in length on preoperative imaging. Patient age ranged from 43 to 80 years.
The IVC required cross-clamping in 24 cases. One patient had two renal veins with two caval thrombi and one patient required a synthetic patch. Surgeries lasted from three to seven hours. None of the operations was converted to open surgery and all but two patients were ambulatory on the day of or day after surgery. Twenty-one patients resumed regular diets the day after surgery. Eight patients had node positive disease and seven patients had distant recurrence 15 months later including four of those with node positive disease.
“This is a complex condition and the complication rate with open surgery is 12% to 47%, depending on the thrombus level, with a mortality rate of 5% to 10%,” explained lead investigator Ronney Abaza, MD, Robotic Surgery Director at OhioHealth Dublin Methodist Hospital. “Using robotic nephrectomy, our complication rate and lack of mortalities compare reasonably with open series with no grade III to V complications, according to the Clavien system, in any patient, including no deaths.”
Dr Abaza added, “While complications were relatively minor in our series, it is evident that complications are not entirely avoidable. Even with a minimally invasive approach, the surgical management of severe cancers in mostly elderly patients will likely involve complications. However, despite the complex and critical nature of these procedures, our series demonstrates favorable outcomes and reproducibility by surgeons with adequate robotic experience.”
This news release describes a study published in the The Journal of Urology whose findings suggest that “robotic nephrectomy” — robotic surgery to remove all or part of a kidney — has higher success rates than traditional open surgery when treating patients for complex clots and tumors associated with renal cell carcinoma. The study is a retrospective look at 32 individual robotic nephrectomy surgeries performed by nine surgeons, beginning with the first in 2008. The case studies involved surgeries performed on patients with inferior vena cava (IVC) tumors ranging from 1 to 11 centimeters in length. The release may have done a bit of a disservice to the quality of the research and the published results. It reads somewhat more promotional than informational and misses the mark on some of our criteria, including costs and quantification of the benefits. It offers some caution when describing the study’s limitations that could be helpful to readers, but the caution stated by the lead researcher in the journal manuscript itself was clearer and stronger.
About 62,700 cases of renal cell cancer are diagnosed in the United States annually and approximately 14,240 deaths are attributed to the disease. Blood clots resulting from the tumor are a frequent occurrence in the renal vein (veins that drain the kidney) and inferior vena cava (veins that carry blood to the heart from the lower body). These clots can compromise blood flow to vital organs. The traditional approach has been open surgery with resulting long convalescent times and inherent risks associated with a large surgical procedure. Several years ago, minimally invasive surgery was introduced with the use of laparoscopic techniques involving cameras attached to thin, lighted tubes that allow surgeons to examine organs closely without open surgery. The use of robotically assisted minimally invasive surgery for removal of clots and tumors is a logical extension to laparoscopy. But like any new surgical technique, the robotic-assisted approach needs to be studied carefully not just for immediate effects, such as convalescent time, complications and blood loss, but also in the context of overall survival.
No mention is made of the cost of the robotic procedure, nor is there any mention of how much the open procedure costs. As we’ve noted in previous reviews and posts, robotic surgery can be very expensive compared to traditional laparoscopic minimally invasive surgery. In some cases, the costs of the robot and the disposables used during a surgical procedure can be in excess of the reimbursement to the sponsoring hospital and those costs are eventually passed on to the consumer. The cost-effectiveness of robotic-assisted minimally invasive surgery is still an open question that we think deserved some discussion in the release.
Citing surgeons, the release notes that robotic nephrectomy for inferior vena cava tumor thrombus “has favorable outcomes in selected patients compared with open surgery, which can have a high rate of complications.”
It then goes on to note that on the complication rate with open surgery is 12% to 47%, depending on the thrombus level, with a mortality rate of 5% to 10%.
But it does not go on to give comparable complication figures for patients who underwent the robotic procedure. Nor does it specify what it means by complications. Here’s the actual data from the study:
“Intraoperative complications occurred in only 1 patient who had a bowel injury during access that was repaired primarily. Postoperative complications occurred in 7 other patients, and included shortness of breath, pneumonia, pulmonary embolism, ileus and emergency room visit for cardiac complaints in 1 patient each, as well as temporary renal impairment not requiring dialysis in 2 patients.”
The director of robotic surgery quoted described the complications in his series as “relatively minor,” but does not specify what he means. If we are quoting the numbers correctly, there was a 25% post-op complication rate seen. We think that there should have been a bit more disclosure.
The published article also notes that two patients (6%) enrolled had positive surgical tumor margins meaning that some residual tumor was left behind.
We found that one of the statements about benefits was probably more useful to surgeons than reporters or patients trying to gauge the research impact: “Using robotic nephrectomy, our complication rate and lack of mortalities compare reasonably with open series with no grade III to V complications, according to the Clavien system, in any patient, including no deaths.” Remember: we are reviewing PR news releases here. These are meant for journalists who, in turn, would report to the public.
The release gives a nod to harms in a comment by the lead surgeon who describes complications from the procedure as “relatively minor” but it could have just as well have said “relatively serious” for all the insight the phrase gave us about harms and risks from the robotic surgery. The surgeon also is quoted saying “even with a minimally invasive approach, the surgical management of severe cancers in mostly elderly patients will likely involve complications.” Again, we are not told what those complications are and their impact on the patient.
The news release suggests in the opening paragraph that the results of this retrospective study are definitive while providing very little to support that contention. Here is how the lead investigator addressed the evidence in the journal article, using proper caution:
“While our series supports a role for robotics in the minimally invasive management of IVC tumorthrombi, open surgery remains the standard therapy. It should also be emphasized that the robotic surgeons who embarked on this procedure did so after extensive experience with other robotic procedures, including kidney surgery. Given the complexity of the procedure and potential major intraoperative complications, including death, the procedure should be approached cautiously.”
The news release would have been better if it had included that caution.
There’s no evidence of disease mongering in the release.
The release doesn’t tell us who funded the study or if there were any potential conflicts of interest.
The lead author, Ronney Abaza, MD, Robotic Surgery Director at Ohio Health Dublin Methodist Hospital, has conducted training programs on behalf of the manufacturer of the robotic device.
The news release did provide a few comments about open surgery, the standard surgical approach. However, it provides only the associated complication rate. A true comparison would have provided more supportive evidence.
It is clear that robot assisted minimally invasive surgery is available in many institutions and has become the mainstay for prostatic surgery. The news release does point out that the surgeons who participated in the story were experienced with the technique. While implied in some parts of the release and downplayed in others, this is not a surgical procedure that should be undertaken lightly.
The news release notes the history of the procedure and that this is the first multi-institutional study to examine the role of robotically assisted minimally invasive surgery for this condition.
From the published study: “We report our combined experience with this procedure, to our knowledge the first multi-institutional and largest series reported to date.”
“Removal of complex renal tumors performed safely by robotic surgery in selected patients,” trumpets the headline. But nowhere do we learn what “safely’ means.
The lede says that “robotic nephrectomy for inferior vena cava tumor thrombus has favorable outcomes and reproducibility when performed by surgeons with adequate robotic experience,” but then fails to tell us what “adequate robotic experience” means.
That is a fair question, given that 32 cases were performed in nine centers, and at least one of the surgeons was responsible for 10 procedures. That leaves 22 for the other eight, or fewer than three per surgeon over a time span that began in 2008 and is only now being reported.