It is common to notice stitches remaining long after they were expected to disappear, especially when a healthcare provider mentioned they were “dissolvable” or “absorbable.” The persistence of surgical threads raises questions about the healing process and whether the body is reacting appropriately to the foreign material. Understanding why a stitch has not dissolved requires looking closely at the type of suture material used and the complex biological environment of the wound itself.
Understanding Absorbable Versus Non-Absorbable Sutures
The primary reason stitches remain is that they were never designed to dissolve. Surgical sutures fall into two categories: absorbable and non-absorbable. Non-absorbable types, made from materials like nylon, polypropylene, or silk, provide long-term wound support and must be manually removed by a clinician after healing.
Absorbable sutures are designed to break down harmlessly within the body over a predetermined period, eliminating the need for removal. Synthetic absorbable materials, such as polyglactin (Vicryl) or polydioxanone (PDS), are primarily broken down through hydrolysis. This mechanism involves water molecules penetrating the polymer chains, gradually breaking chemical bonds and reducing the material’s strength.
Natural absorbable materials, like plain or chromic catgut, are broken down by the body’s own enzymes. The time frame for synthetic sutures to disappear varies significantly, with some dissolving in 60 to 90 days, while others can take up to 200 days. The material chosen depends on the tissue being closed and the required support during healing.
Factors That Slow or Prevent Suture Dissolution
If absorbable sutures are delayed in disappearing, it indicates factors are interfering with the normal breakdown process. Hydrolysis relies on the presence of water and is impacted by the environment around the suture. Conditions such as poor blood supply, or low vascularity, at the wound site can slow the delivery of fluids required for absorption.
The size and construction of the suture also play a role, as thicker sutures contain more material and take longer to dissolve. The chemistry of the local tissue environment, including its pH level, can affect degradation rates.
Local infection and inflammation can disrupt the expected timeline for suture dissolution. Infection generally creates a hostile environment that delays the organized healing process, making dissolution less predictable. Sutures placed in deep, less-hydrated tissues may also have a slower rate of absorption due to differences in fluid exposure.
A patient’s overall health, including their metabolic rate and conditions like diabetes, contributes to the body’s general healing speed. This healing speed indirectly affects how quickly the stitches are absorbed.
Physical Reactions to Undissolved Sutures
When a suture remains in the tissue longer than intended, the body may react to it as a persistent foreign object. One common reaction is suture extrusion, sometimes called the stitch “spitting” out. This occurs when the body attempts to push the foreign material out through the skin surface, often appearing as a small loop or fragment of thread.
A more concerning reaction is the formation of a suture granuloma, which is a localized, inflammatory lump. This benign response occurs when immune cells cluster to wall off the foreign material, forming a palpable mass. Suture granulomas are more common with non-absorbable materials but can occur with absorbable ones if the material is not fully broken down.
Necessary Steps and Medical Consultation
If stitches that were supposed to dissolve are still present, first check the expected timeline provided by the surgeon, as absorption can take weeks or months. If the stitches are causing irritation or remain visibly intact well past the predicted date, consult a healthcare provider.
Immediate medical attention is necessary if signs of a wound infection develop. These signs include increasing redness, warmth, swelling, severe pain, pus or discharge, or a fever.
If the stitches are confirmed to be the non-absorbable type, they must be removed by a professional. Attempting to pull them out at home can cause trauma, introduce bacteria, and disrupt the healing wound.
Before calling the surgeon’s office, gather details about the operation date, the location of the sutures, and any information provided about the specific suture material used. This information will guide the doctor’s assessment and next steps.