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Stress Can Hinder Wound Healing After Surgery

By Rebecca Ostrom for Wounds1

A new study shows that worrying about surgery before it occurs may slow healing afterwards.

Researchers in Auckland, New Zealand, conducted a study of 47 hernia patients. Patients were asked to fill out a questionnaire before and after their surgery detailing how they were feeling about the surgery. Researchers took blood samples before
and after the procedure and wound fluid samples after the surgery. Keith J. Petrie, Ph.D., and his colleagues at the University of Auckland, reported their findings in the September/October issue of Psychosomatic Medicine.

The patients’ fluid samples showed that those who indicated high stress levels, particularly stress about the surgery, had lower levels of interleukin-1 and matrix metalloproteinase 9 (MMP-9), two substances that help in the wound healing
process. The study also showed that patients who were more worried had a more painful, poorer, and slower recovery.

Interleukin-1 is an immune system protein that causes inflammation, the first step of wound healing. After surgery or other wounds, the inflammation generated by interleukin-1 activates the white blood cells that fight disease and infection.
Interleukin-1 also stimulates the growth of scab tissue and helps wounds close.
MMP-9 is an enzyme that helps regulate the connective tissue formed during the healing of wounds. While an excess of either of these substances can lead to other health problems, the depressed level shown in patients who are stressed about surgery can slow and weaken the healing process.

The lowered MMP-9 level does not seem to be caused by general anxiety or stress,
but only by stress about the surgery. Interleukin-1, however, can be affected by stress unrelated to the surgery.

The New Zealand study is the first to show how stress can affect patients
undergoing real-life procedures, not just lab tests. This study complements similar tests that
have been done in controlled settings, such as a 1999 study in which patients were given blisters and then tested for interleukin levels.

The 1999 study, conducted by Janice Kiecolt-Glaser at the Ohio State College of Medicine, also linked the lowered interleukin levels with the hormone cortisol. Those who had a higher level of stress also had increased levels of cortisol. Higher levels
of cortisol are known to suppress the immune system and slow healing. This
research studied women with average stress levels. Those anticipating surgery or suffering from depression would likely have an even stronger response.

A further study conducted by the same research team showed that patients who used relaxation techniques had improved wound healing over those who did not.

The research indicates that taking steps to reduce a patient’s stress before surgery, through counseling or anti-anxiety medication, may improve healing. These anti-anxiety steps have already been found to shorten hospital stays and reduce complications, pain, and distress after surgery. Now there is hope it may also help wounds heal
faster.