Breast implants are considered foreign objects by the body, which triggers a natural biological defense mechanism. This response involves the formation of a layer of scar tissue around the implant, known as the fibrous capsule, which essentially walls off the object from the surrounding healthy tissue. The presence of this capsule is a standard outcome following any implant surgery. Understanding this reaction dictates the long-term interaction between the body and the device. This article will examine the nature of this tissue, why it remains permanent, and the options available when it causes complications.
The Body’s Natural Reaction Defining the Fibrous Capsule
The formation of the capsule is termed the foreign body reaction. This reaction is the body’s attempt to isolate any non-biological material placed inside it, and it occurs with devices like pacemakers and joint replacements as well as breast implants. The capsule begins to form immediately after the implant is placed, starting with a layer of granulation tissue that matures over time.
The resulting capsule is a dense layer of scar tissue composed primarily of collagen fibers, which are produced by cells called fibroblasts. This tissue is generally avascular, meaning it lacks a significant blood supply. In a normal, healthy state, the capsule is thin, soft, and pliable, helping to keep the breast implant in a stable position.
Why the Capsule Does Not Dissolve
The fibrous capsule does not dissolve because it is permanent scar tissue. Scar tissue, unlike the temporary inflammation that precedes it, is a structural repair mechanism designed for long-term integrity and strength. This dense collagen matrix is a final product of the healing process and is not subject to the normal biological turnover that softer tissues experience.
The body lacks the necessary enzymatic mechanisms to completely break down and resorb this organized, mature collagen layer once it has fully formed. The capsule is intended to be a permanent barrier, a stable wall between the implant and the surrounding breast tissue, ensuring the body’s inflammatory response remains contained. The capsule does not possess a biological “dissolution switch” because its function is to stabilize the foreign object for decades.
Capsular Contracture When the Tissue Tightens
The primary complication associated with the fibrous capsule is capsular contracture, which occurs when this scar tissue abnormally tightens and shrinks around the implant. This pathological tightening is often caused by a chronic inflammatory response, triggered by factors like a subclinical bacterial biofilm on the implant surface or a hematoma (collection of blood) occurring after surgery. The excessive contraction is driven by specialized cells within the capsule called myofibroblasts, which exert a pulling force on the tissue.
Capsular contracture can lead to a breast that feels firm, distorted, and in more severe cases, can cause chronic pain. Clinicians use the Baker Grading System to assess the severity, ranging from Grade I, where the breast is soft and looks natural, to Grade IV, where the breast is hard, painful, and visibly misshapen. Grade II involves slight firmness without distortion, while Grade III presents with both firmness and a visible abnormality in breast shape. The risk of developing some degree of contracture is estimated to affect approximately one in six women with breast implants over their lifetime.
Surgical Removal and Management Options
Surgical intervention is often required to address moderate to severe capsular contracture (Baker Grades III and IV). The procedure to remove the scar tissue is called a capsulectomy. This intervention involves removing the implant and the surrounding capsule tissue to alleviate the tightness and restore a softer breast contour.
There are two main surgical approaches: a total capsulectomy involves the complete removal of the entire capsule. A partial capsulectomy removes only a segment of the capsule, leaving some tissue behind, and is generally reserved for less severe cases. Non-surgical management can be attempted for mild contracture, sometimes involving external ultrasound therapy or medications like leukotriene inhibitors, which block inflammatory pathways that contribute to scar tissue formation. These non-surgical methods are less effective for advanced, well-established contractures.