By Megan Brooks
NEW YORK (Reuters Health) - One out of every eight patients who undergo abdominal surgery will develop an incisional hernia and a new smartphone app developed by a team from the University of Pennsylvania Perelman School of Medicine can accurately predict a patient's risk for IH at the bedside.
The PENN Hernia Risk Calculator "presents the risk for each case at the point of care, giving surgeons and patients the chance to consider this outcome ahead of time and incorporate data into the decision-making process," Dr. John Fischer, assistant professor of surgery in the division of plastic and reconstructive surgery, said in a statement. He presented the app and its development April 12 at the American Surgical Association annual meeting in Dallas, Texas.
Costs related to incisional hernias in U.S. hover around $7.3 billion annually due to the number of these cases and the quality of life issues they cause.
The Penn hernia research team set out to identify patients and operative factors independently associated with IH after abdominal surgery; create predictive models for IH across individual surgical subspecialities; and generate a portable user-friendly IH prediction app.
To accomplish this, they analyzed the electronic health records of 29,739 patients undergoing intra-abdominal, urologic, or gynecologic surgery at Penn between January 2005 and June 2016. Altogether, 1,127 of these patients (3.8%) developed IH and required a second surgery to repair it.
Colorectal surgeries were most commonly associated with IH, followed by vascular, bariatric and transplant procedures. "Pervasive" risk factors for IH after abdominal surgery include a prior history of abdominal surgery, smoking, obesity, open surgery, acute infection and two or more Elixhauser comorbidities, Dr. Fischer said.
The PENN Hernia Calc app combines these factors and other relevant data to generate a real-time risk score for each patient, with a C-statistic 0.8 to 0.9 (with 1.0 perfect and 0.5 chance) in testing.
As an example, the app calculates that a 68-year-old male with a history of smoking, hyperlipidemia, anemia and prior abdominal surgery undergoing sigmoid colectomy would have a 22% risk of IH.
A limitation of the current analysis is the single-center design with no external validation.
The app hasn't been prospectively or externally validated yet, Dr. Fischer told Reuters Health by phone, "but we know in the dataset we have and the patients we studied that it predicts both accurately and very efficiently the risk of hernia. If it's used for its intended purpose, to paint a picture at the bedside for what a patient's estimated risk might be, it's absolutely usable right now," he said.
The Penn Hernia Risk Calculator is available through Google Play and Apple iTunes app stores.
American Surgical Association Annual Meeting 2019.