Patients who have undergone open ventral abdominal hernia repair see significant improvements in some self-reported pain measures at 6 or more months after surgery, according to results from a new study.

The investigators, led by Eugene Park, MD, of Northwestern University, Chicago, suggested that the timing of the improvements may have to do with the mesh used in the surgeries.

More than half of patients with ventral hernias report pain before repair, and pain is one indication for surgery. However, Dr. Park and his colleagues wrote, “many surgeons still believe that surgical repair of a hernia does not address the problem of pain.” Reported incidence of persistent pain after hernia repair ranges from 24% to 44% in the literature, they noted.

For their research, published in the January issue of The American Journal of Surgery ( 2017;213:58-63 ), Dr. Park and his colleagues recruited 77 patients scheduled for midline incisional ventral hernia repair between 2010 and 2013 (mean age, 54 years; 45% female), who completed detailed pain surveys before surgery and during all postoperative visits; 38 patients completed surveys at least 6 months after surgery. All surgeries were performed by one of the study authors, Gregory A. Dumanian, MD , also of Northwestern.

The investigators used pain surveys from the Patient-Reported Outcomes Measurement Information System (PROMIS) , which was developed under the National Institutes of Health. The investigators called the PROMIS surveys, which are computer based, a “rigorous and reliable tool” to measure patient feedback in clinical research and healthcare settings. PROMIS is designed to measure, among other things, how pain impacts a patient’s behavior and interferes with his or her everyday functioning.

Dr. Park and his colleagues reported that the patients with at least 6 months of follow-up saw significant improvement in measures of pain interference (P less than 0.05), though not in pain behavior .

The researchers wrote in their analysis that the mesh used in securing the hernia repair – all patients in the study were treated with some type of mesh – might be why pain scores were seen to improve significantly at around 6 months.

“The changes noted in pain interference at the 4- to 8-month time frame may represent a physiologic change as the mesh solidly integrates and begins to contribute to a patient’s increasing ability to perform tasks.”

The mesh used in the study, the researchers also noted, was narrower than that generally reported for hernia repairs of this type.

Dr. Park and his colleagues described as limitations of their study the relatively small number of patients completing long-term follow-up. Also, the investigators noted, the PROMIS pain interference and pain behavior surveys “were not designed specifically with ventral hernia patients in mind, which may limit the scope of hernia-related symptoms covered” and that data on patients’ use of pain medications was not recorded.

The study authors reported no outside funding or conflicts of interest related to their findings.