Robot-assisted pancreaticoduodenectomy (RPD) showed short-term advantages over open pancreaticoduodenectomy (OPD) -- better known as the Whipple procedure – but only after surgeons had successfully negotiated the learning curve, Chinese researchers reported.
In a retrospective study, Baiyong Shen, MD, PhD, of Ruijin Hospital in Shanghai, and colleagues found reductions in operative time and blood loss with the less invasive procedure, although there appeared to be no differences in postoperative complications. "However, patients recovered more quickly after RPD than after OPD. A prospective randomized clinical trial is needed in the future to verify these results," the authors wrote online in .
From May 2010 to December 2018, a total of 450 patients underwent the complex surgery at the hospital's high-volume Pancreatic Disease Center, an affiliate of Shanghai Jiaotong University.
After one-to-one propensity-score matching, 187 cases each of RPD and OPD were identified. In the RPD group, 78 patients (41.7%) were women, and mean age was 60.9, while in the OPD arm, 80 patients (42.8%) were women, and mean age was 60.1.
A body mass index of at least 24 was present in 37.5% of patients in the robotic group and 26.3 in the open surgery arm. Tumors were a mean of 2.7 cm and 3.2 cm, respectively.
The following advantages over OPD emerged with RPD, the results showed:
- Mean operative time 279.7 minutes (SD 76.3) vs 298.2 minutes (SD 78.3, P=0.02)
- Mean estimated blood loss 297.3 mL: (SD 246.8) vs 415.2 mL (SD 497.9, P=0.002)
- Mean postoperative length of hospital stay 22.4 days (SD 16.7) vs 26.1 days (SD 16.3, P=0.03)
- Abdominal infection rate 21.4% vs 34.2% (P=0.008)
No significant inter-arm differences emerged in the reoperation resection rate (5.3% vs 7.0%, P=0.68). Nor was there a notable difference in the incidence of postoperative complications such as pancreatic fistula, bile leak, and delayed gastric emptying.
Asked for his perspective, A. James Moser, MD, of the Pancreas and Liver Institute at Beth Israel Deaconess Medical Center in Boston, who was not involved with the research, said the findings confirm his center's recent series comparing RPD and OPD and the institution's other propensity-matched, non-randomized comparisons of these two procedures.
"Both our and the Chinese series demonstrate a learning curve of nearly 250 patients to achieve results equivalent to the existing open procedure," Moser told . "High volume U.S. centers within the American College of Surgeons National Surgical Quality Improvement Program would require approximately 15 years to achieve this benchmark for the robotic procedure."
Moser said the observed reductions in length of stay in China are unlikely to be reproduced in the U.S. because of systemic differences between the U.S. and Chinese healthcare systems.
"The likelihood of yet-to-be detected improvements in patient recovery after robot Whipple is at best low, and the applicability of the procedure within the United States is limited by the duration of the required learning curve," he continued. "I leave it to your readership to decide whether further investigation of these robotic procedures should be pursued when the expected outcome is likely to be the same."
As a new technique, RPD is thought to have a learning curve similar to that of other minimally invasive pancreatic surgeries such as laparoscopic pancreaticoduodenectomy, the investigators noted. In their significant inflection points in the learning curve were evident at 100 and 250 cases, especially the latter.
"We discovered that the surgeon's skills rapidly improved and reached a stable level after 250 cases," Shen and co-authors wrote. "However, the effectiveness and feasibility of RPD remains controversial around the world."
The critical point on the learning curve has varied widely across RPD studies, from 33 and 40 cases to 70, 80, and noted the investigators, who said they are conducting ongoing randomized clinical studies to verify the advantages of RPD.
Earlier this year, a randomized Dutch study reported that another newer Whipple technique, laparoscopic pancreatoduodenectomy, was associated with more complication-related deaths than open surgery but offered no benefits in time to functional recovery or improved quality of life.
Limitations to the current study, Shen and colleagues said, were its retrospective design and the bias in patient selection since there were more cases of malignant pancreatic tumors and chronic pancreatitis in the OPD group, making surgery more difficult.
Disclosures
The study was funded by the National Natural Science Foundation of China.
Shen and co-authors reported having no conflicts of interest.
Moser reported support from the Alliance of Families Fighting Pancreatic Cancer and the SAGES and Intuitive Surgery Research Foundation for the study of the efficiency and outcomes of robotic surgery; he is principal investigator for the Project Survival effort to discover diagnostic and therapeutic biomarkers for pancreatic cancer.
Primary Source
JAMA Surgery
Shi Y, et al "Short-term Outcomes after Robot-Assisted vs Open Pancreaticoduodenectomy after the Learning Curve" JAMA Surg 2020; doi:10.1001/jamasurg.2020.0021.