Pancreatic Surgery: Robot vs Surgeon, Volume Important

Minimally invasive techniques for pancreatic surgery are associated with a significantly increased risk for complications when performed in low-volume hospitals in which relatively few procedures are performed per year, warn US investigators.

The researchers found that in hospitals in which 22 or fewer minimally invasive pancreaticoduodenectomies (MPDs) were performed per year, the rate of complications was increased by three quarters compared with that in higher-volume hospitals.

“The identified threshold of 22 cases per year may serve as a foundation for protocols aimed at safer implementation of MIPD at the national level, and may have implications for surgical education and training,” write Julie A. Sosa, MD, Section of Endocrine Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina, and colleagues.

The study was published in JAMA Surgery on December 28, 2016.

However, in more reassuring findings, an international study of almost 3000 pancreaticoduodenectomies showed that in the hands of experienced surgeons, robotic pancreatoduodenectomy (RPD) was associated with a rate of major complications similar to that of open pancreatoduodenectomy (OPD).

This case-matched analysis, which was also published in JAMA Surgery on December 28, indicated that clinically relevant pancreatic fistula, the most common and morbid complication of pancreaticoduodenectomy, occurs after RPD at rates similar to those seen after open OPD.

RPD was also noninferior to OPD on a number of other measures, including the occurrence of any complication, hospital stay, and 90-day mortality.

“This study adds to a growing body of evidence that dispels reports of inferior perioperative outcomes for minimally invasive PD, provided these procedures are performed by high-volume pancreatic surgeons in a systematic and structured setting, and lays the foundation for longitudinal patient-centered assessments of various approaches to pancreaticoduodenectomy,” these authors comment.

In a commentary published with the study, Hong Jin Kim, MD, Division of Surgical Oncology and Endocrine Surgery, University of North Carolina School of Medicine, Chapel Hill, and colleagues describe the study as a “reasonable attempt” to compare the two procedures.

Casting doubt on whether the findings could be extrapolated to other centers, they say: “Although the authors demonstrate the safety of this approach with highly trained physicians at one high-volume center, the wide adaptability and impact of RPD remains in question,” adding that innovations “should improve standards of care, rather than settling for noninferiority”.

Hospital Volume Affects Success Rate

In the first article, Dr Sosa and colleagues note that MPD “is a technically challenging and complex surgical procedure” and that previous data have suggested that outcomes are linked to hospital volume.

To investigate further, they identified all 865 patients from the Healthcare Cost and Utilization Project National Inpatient Sample who underwent MPD between 2000 and 2012. They gathered data on all complications that occurred up to August 2016.

Of the patients who underwent MPD, 55% were men (median age, 67 years). The diagnosis was cancer in 86% of patients; the remaining 11% had benign conditions or pancreatitis.

The median hospital volume for MPD was six cases per year (range, 1 to 60 cases per year). In contrast, the median number of OPDs performed in the same hospitals was 27 cases per year (range, 9 to 62 cases per year).

During the study period, the use of MPD increased by more than 400%, from 14 cases in 2000 to 125 cases in 2012. Overall, 57% of procedures were performed in hospitals in which fewer than 10 cases were performed per year; 20% were performed in hospitals in which only one case was performed per year.

After taking into account demographic and clinical characteristics, the team found that increasing hospital volume was associated with a significant reduction in complications (P < .001 overall), up to a threshold of 22 cases per year.

Dr Sosa and colleagues also found that 83% of patients underwent MPD at a hospital that performed 22 cases or fewer per year. This was used to define a “low-volume” hospital.

Adjusting for case mix, they calculated that undergoing MPD at a low-volume vs high-volume hospital was associated with a significantly increased risk for postoperative complications (odds ratio [OR], 1.74; P = .04).

The team writes: “This finding is timely and relevant, given the ongoing debate regarding safe implementation of this complex procedure and the current shift toward value-based health care reimbursement models.”

In an accompanying commentary, Marco Del Chiaro, MD, PhD, Karolinska Institutet at the Center for Digestive Diseases, Karolinska University Hospital, Stockholm, Sweden, and colleagues point out that the number of MPDs performed has been increasing worldwide, “despite a lack of well-designed prospective randomized trials supporting the advantages of minimally invasive procedures over traditional ones.

“In our opinion, it is also noteworthy that these procedures are heterogeneously distributed among different hospitals and, more interestingly, they are unequally distributed among hospitals with different surgical volumes,” they add, highlighting the finding that the majority of cases are “reserved to low-volume hospitals.”

They emphasize that the tools for minimally invasive surgery should be “in the hands of pancreatic surgeons” and that “skills in minimally invasive approaches cannot compensate for the lack of experience in pancreatic surgery and in pancreatology.”

Surgical volume, rather than use of minimally invasive approaches, “might play the major role in determining postoperative and long-term survival outcomes” in major pancreatic surgery, they conclude.

Robotic vs Open Surgery

In the second article, senior author Charles Vollmer Jr, MD, from the Department of Surgery at the University of Pennsylvania Perelman School of Medicine in Philadelphia, and colleagues compared complications occurring after RPD and OPD.

They studied outcomes for 2846 patents who underwent pancreatoduodenectomies, including 2661 OPDs and 185 RPDs, performed by 51 surgeons at 17 institutions worldwide between 2003 and 2015. Overall, 51.5% of the patients were men (median age, 64 years).

All OPDs were performed at 16 institutions by 48 surgeons who had passed the OPD learning curve, defined as the completion of 60 consecutive procedures.

The RPDs were conducted at the University of Pittsburgh Medical Center by three surgeons who had passed the RPD learning curve of 80 consecutive procedures.

Adjusting for potential confounders, the researchers found that in the overall cohort, RPD was associated with a significant reduction in the risk for clinically relevant pancreatic fistula compared with OPD (OR, 0.4; P = .002).

Other factors associated with fistula risk included soft pancreatic parenchyma (OR, 4.7; P < .001), pathologic findings of high-risk disease (OR, 1.4; P = .01), omission of intraoperative drains (OR, 0.5; P = .005), and octreotide prophylaxis (OR, 3.1; P < .001).

Small pancreatic duct diameter was also associated with the risk for fistula, and an increase in intraoperative blood loss was an independent predictor of fistula.

To minimize bias from the nonrandomized treatment assignment, the team also performed propensity score matching to account for factors significantly associated with either procedure. They identified a well-matched cohort of 152 RPDs and 152 OPDs.

This showed that there was no significant difference in fistula rates between RDP and OPD, at 6.6% vs 11.2% (P = .23). There were also no significant differences in rates of grade B fistula (6.6% vs 9.2%; P = 0.52) and grade C fistula (0.0% vs 2.0%; P = .25).

There were also no significant differences between RPD and OPD in terms of the occurrence of any complication (73.7% vs 66.4%; P = .21), severe complications of grade ≥3 (23.05% vs 23.7%; P < .99), hospital stay (median 8.0 days vs 8.5 days; P = .31), 30-day readmission (22.4% vs 21.7%; P > .99), and 90-day mortality (3.3% vs 1.3%; P = .38).

Despite the positive findings, the researchers point out that “in the current climate of value driven health care, the cost of using the robotic platform for complex procedures, such as pancreaticoduodenectomy, needs to be carefully examined.” They add that studies examining indirect costs, such as quality of life and completion of adjuvant therapy, are “urgently needed.”