CHICAGO: A modified Fistula Risk Score (FRS) based on data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP®) will allow surgeons across the country to better identify patients at high risk for anastomotic leak following surgical resection of the pancreas so they can employ pre- and intraoperative measures designed to mitigate that risk. The modified FRS also will help surgeons more effectively assess the quality of patient care and evaluate new interventions that may prevent fistula development. The risk score was described in a study that appears as an "article in press" on the Journal of the American College of Surgeons website in advance of print publication.
Since 2011, surgeons have relied on a FRS that was initially developed by Mark Callery, MD, FACS, in the department of surgery at Beth Israel Deaconess Medical Center, Boston, and Charles Vollmer, MD, FACS, director of pancreatic surgery at the University of Pennsylvania, from retrospective reviews of patient care in a small number of academic medical centers that treat high volumes of patients with pancreatic cancer. The original FRS has been validated in several larger studies, among them a prospective evaluation of 577 patients treated in 2011-2012 as well as an additional 3,096 patients treated in several high volume centers internationally in 2014. 1,2,3 This original risk score incorporates several operative variables that cannot be easily determined prior to a surgical procedure or are difficult to measure accurately, such as intra-operative blood loss.
The modified FRS presented in this study overcomes some of the inherent bias associated with smaller data sets that reflect clinical practice in only a few surgery centers. "NSQIP gives us a tightly controlled data set with well-defined variables and it accrues information from patient populations treated in low, medium and high-volume centers across the country and around the world. NSQIP gives us a much broader base from which to develop risk-predictive models," said Marshall S. Baker, MD, MBA, FACS, study coauthor and an associate clinical professor of surgery, NorthShore University HealthSystem, Evanston, Ill.
"NSQIP provides not only highly accurate and reliable patient, clinical, and surgical data. It is also generalizable and can be applied to patients who are treated for pancreatic cancer in many types of surgery centers in the community," said Clifford Ko, MD, MS, MSHS, FACS, Director of the ACS Division of Research and Optimal Patient Care, which administers NSQIP.
The modified FRS was developed using the NSQIP Pancreatic Demonstration Project. The demonstration project was initiated and driven by Henry Pittm MD, FACS, professor of surgery at Indiana University, to capture procedure specific outcomes measures for pancreatectomy done in 43 hospitals within NSQIP. Researchers involved in this project applied NSQIP Pancreatic Demonstration Project data to study 1,731 patients who had undergone pancreaticoduodenectomy, also known as the Whipple procedure, between 2011 and 2012. The Whipple procedure involves surgical removal of the head of the pancreas, upper part of the duodenum, and bile duct and reconnection of those structures to the intestinal tract. Leakage, or a fistula, occurs when enzymes from the remaining portion of the pancreas erode through suture lines and intestinal fluids escape into the abdomen.
The researchers assessed 47 preoperative and intraoperative variables that were present in 1,154 patients treated for a clinically relevant pancreatic fistula. A point score was assigned to each variable that indicated whether or not it was associated with increased odds of fistula formation. This process identified five risk factors as significant predictors of fistula: male gender, body mass index equal of greater than 25, preoperative total bilirubin level less than 2.0 mg/dL, small pancreatic duct size, and soft gland texture.
The result of this analysis is a risk model that may be used to identify at-risk patients prior to their operations. "While the original risk model focused on intraoperative factors surgeons couldn't determine ahead of time, this model employs several variables that can be used to stratify risk preoperatively so surgeons can determine which patients are at high risk and take steps in the OR that prevent or modify risk of leak," Dr. Baker said.
The modified FRS gives surgeons a point of reference to understand the quality of the care they provide. "If surgeons take care of high-risk patient populations but their fistula rates are low, they can substantiate that they are achieving the quality of care they should. If they are caring for low-risk patient populations but fistula rates are high, they can develop local strategies to improve fistula prevention and treatment," he added.
The risk score also gives researchers a framework for studying fistula going forward. "We are able to use the risk score to assess how well new interventions and treatment strategies minimize the risk of fistula. Such clinical trials will be easier to do because the NSQIP platform gives us a dataset that accrues study populations quickly and broadly across a wide variety of surgical practices," Dr. Baker concluded.
"The development of the modified FRS is a good example of the role of NSQIP as a clinical registry that collects and provides reliable data to advance the evaluation of surgical techniques and the care of patients," Dr. Ko concluded.
In addition to Dr. Baker, other study authors include Olga Kantor, MD; Mark S. Talamonti, MD, FACS; Charles M. Vollmer, MD, FACS; Henry Pitt, MD, FACS; Taylor S. Riall, MD, PhD, FACS; Bruce L. Hall, MD, PhD, MBA, FACS; and Chi-Hsiung Wang, PhD.
"FACS" designates that a surgeon is a Fellow of the American College of Surgeons. Citation: Using the Pancreatic Demonstration Project to Derive a Modified Fistula Risk Score for Preoperative Risk Stratification in Patients
Undergoing Pancreaticoduodenectomy. Journal of the American College of Surgeons. DOI: http://dx.doi.org/10.1016/j.jamcollsurg.2017.01.054.
1 Callery MP, et al. A prospectively validated clinical risk score accurately predicts pancreatic fistula after pancreaticoduodenectomy. J Am Coll Surg. 2013; 216:1-14.
2 Miller BC, et al. A multi-institutional external validation of the fistula risk score for pancreaticoduodenectomy. J Gastrointest Surg. 2014; 18:172-179.
3 Shubert CR, et al. Clinical risk score to predict pancreatic fistula after pancreaticoduodenectomy: independent external validation for open and laparoscopic approaches. J Am Coll Surg. 2015; 221:689-698.
About the American College of Surgeons
The American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for all surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has more than 80,000 members and is the largest organization of surgeons in the world. For more information, visit http://www.facs.org.
Journal of the American College of Surgeons