Robotics no help in cystectomy

A randomized trial comparing robotic with open cystectomy ended early after an interim analysis showed the minimally invasive approach did not reduce complications, according to a researchers.

When the trial ended, 62% of patients in the open cystectomy arm had grade 2-5 complications in the first 90 days after surgery compared with 61% in the robotic cystectomy arm.

An analysis of grade 3-5 complications yielded 90-day complication rates of 22% with open surgery and 24% with robotics. Analyses of complications on a per-patient basis also showed no difference between the groups.

Robotics was associated with less blood loss, but open cystectomy required less time to complete.

“This interim result meets the study’s pre-specified criteria for trial closure due to a lack of observed difference between the two arms and, therefore, the study will close to accrual,” Vincent P. Laudone, MD, of Memorial Sloan-Kettering Cancer Center in New York City, said during a presentation at the American Urological Association meeting.

“This study demonstrates that well-designed randomized, controlled trials of new surgical technologies are possible and should be strongly encouraged to better answer important clinical questions.”

Despite representing standard of care for high-risk bladder cancer, radical cystectomy with lymph node dissection and urinary diversion confers significant perioperative morbidity, ranging as high as 60% in some centers, said Laudone.

In recent years, use of robotic radical cystectomy has increased as surgeons attempt to reduce complications and morbidity. Whether robotic assistance has accomplished that goal has yet to be determined.

To compare outcomes between the two approaches to cystectomy, Laudone and colleagues at Memorial Sloan-Kettering performed a randomized trial involving high-risk patients with bladder cancer. Investigators excluded those with prior pelvic radiation therapy, extensive prior surgery, or inability to tolerate the Trendelenburg position.

Eligible patients were randomized to open radical cystectomy with lymph node dissection and urinary diversion or to robotic radical cystectomy with extracorporeal urinary diversion. The primary endpoint was grade 2-5 complications during the first 90 days after surgery.

The trial had an accrual goal of 105 patients in each treatment group, which provided the statistical power to detect a 20% absolute difference in the primary endpoint. The protocol mandated an interim analysis after accrual of 100 patients.

Investigators used a modified Clavien Scale to determine complications. Grade 1 included use of oral medications or bedside intervention. Grade 2 included IV medications and need for total parenteral nutrition. Grade 3 represented need for additional interventions. Grade 4 referred to lasting disability or organ loss, and grade 5 was patient death.

Secondary objectives of the trial included surgical time, blood loss, length of stay, pathologic findings, and oncologic outcomes. Follow-up will continue for at least 2 years.

Of the first 124 patients randomized, 116 had undergone surgery when the trial ended, and 109 patients had at least 90 days of follow-up.

The patient population had a mean age of 65 to 66, and about three-fourths had ASA surgical risk scores of 3 or 4. About a third of the robotic group and almost half of the open group received neoadjuvant chemotherapy.

Urinary diversion ileal conduit was performed in 46% of robotic patients and 40% of the open-surgery group, neobladder in 54% of each group, and continent cutaneous diversion in 5.3% of patients in the open group. Pathologic T stage did not differ significantly between groups, as 55% to 60% in both groups had T0, Tis, Ta, or T1 and 30% to 35% had T4.

The interim analysis showed no difference in 90-day complication rates. The number of grade 2-5 complications per patient averaged 1.5 and the mean for grade 3-5 complications was 0.3 per patient.

Operative time averaged 454 minutes in the robotic group and 328 in patients who underwent open surgery (P<0.001). Blood loss averaged 518 mL in the robotic group and 679 mL in the open group (P=0.015).

The average number of lymph nodes examined was 30 in the robotic group and 25 in the open group, a nonsignificant difference. Rates of positive nodes were 17% in the robotic group and 16% in the open group. Length of stay averaged 8 days in both groups.

“Subsequent data analysis, including cost and quality of life outcomes, will be performed for this study,” said Laudone. “At Memorial Sloan-Kettering Cancer Center, we will continue to investigate newer modifications in robotic surgical technique, such as intracorporeal diversion, in the setting of future prospective trials.”

Disclosure: Laudone and co-investigators had no relevant disclosures.

Reference:  Laudone VP, et al “Interim analysis of a prospective, randomized trial comparing robotic and open radical cystectomy.”