Capsular contracture is one of the most common complications following implant-based breast reconstruction after a mastectomy. This condition involves the tightening and hardening of the internal scar tissue, known as the capsule, which naturally forms around any foreign object, including a breast implant. While a soft, protective capsule is a normal physiological response, contracture occurs when this tissue becomes dense and constrictive. This can lead to symptoms such as firmness, distortion of the breast shape, and discomfort.
The Biological Mechanism Behind Scar Tissue Formation
The body’s initial response to a breast implant is a foreign body reaction that begins immediately after surgery. Specialized immune cells, such as macrophages, infiltrate the area, initiating a chronic inflammatory cascade. This process results in the creation of a fibrous envelope, or capsule, composed primarily of collagen fibers, which isolates the implant from the rest of the body.
The complication arises when this capsule undergoes an exaggerated process of fibrosis and contraction. Normal connective tissue cells called fibroblasts transform into myofibroblasts. These myofibroblasts are similar to the cells that cause a wound to contract during healing, but they remain activated, producing an excessive amount of collagen. They organize these fibers into thick, cable-like structures.
This overproduction and reorganization of collagen causes the capsule to shrink and squeeze the implant. The inflammatory environment is often sustained by cytokines and other profibrotic factors, creating a self-perpetuating cycle of contraction.
Identifying the Severity Using the Baker Scale
The severity of capsular contracture is standardized using the Baker Scale, the most widely adopted grading system. This scale assesses the feel and appearance of the reconstructed breast, guiding management decisions. Grade I represents the mildest form, where the breast remains soft and appears natural, often undetectable to the touch.
Progression to Grade II means the breast is slightly firm but maintains a nearly normal appearance without significant visible distortion. Grade III indicates that the breast is firm and the contracture has caused a visible distortion in the shape or position of the implant. Although the breast is firm and looks abnormal, it may not be painful.
The most severe form is Grade IV, where the breast is hard, painful, and exhibits a severe, noticeable distortion. This level of severity results from the highest degree of scar tissue tightening and is the grade most likely to require surgical intervention.
Factors That Increase Risk
Several factors beyond the body’s natural healing response can significantly increase the likelihood of developing capsular contracture. A history of post-mastectomy radiation therapy is a substantial risk factor, dramatically increasing the odds of developing the condition. Radiation alters the tissue environment, promoting chronic inflammation and fibrosis that leads to excessive scar formation.
Procedural complications, such as a hematoma (a collection of blood) or seroma (a collection of fluid) after surgery, also elevate the risk. These fluid collections provide an environment rich in inflammatory mediators that exacerbate the foreign body reaction. A subclinical infection, often caused by a thin layer of bacteria called biofilm on the implant surface, is also believed to trigger a persistent, low-grade inflammatory state.
Implant Characteristics and Placement
The characteristics of the implant and its placement location influence the risk profile. Placing the implant fully beneath the chest muscle (submuscular) is generally associated with a lower rate of contracture compared to placing it above the muscle (prepectoral or subglandular). Furthermore, the implant surface texture plays a role, as smooth implants historically showed a higher rate of contracture than certain types of textured implants, although the use of textured implants is now managed carefully due to other concerns. Surgical techniques, such as meticulous control of bleeding and the use of acellular dermal matrix (ADM), are employed to mitigate these risks.
Treatment Options and Surgical Correction
Management strategies for capsular contracture vary widely depending on the severity as classified by the Baker Scale. For mild cases (Grade I or II), non-surgical approaches may be considered to maintain tissue softness. Gentle, regular massage is often recommended post-operatively to help keep the capsule flexible, though its effectiveness once contracture is established is limited.
Medications, such as leukotriene inhibitors originally developed for asthma, have been used for milder contractures due to their anti-inflammatory properties. However, these non-surgical methods typically offer only limited improvement for advanced cases (Grade III and IV). For these more severe and symptomatic cases, surgical correction becomes the most reliable treatment option.
The most common surgical procedure is a capsulectomy, which involves the complete removal of the hardened scar tissue capsule. Surgeons may also perform a capsulotomy, which means making cuts in the capsule to release tension and allow the implant to expand. In nearly all surgical revisions for severe contracture, the existing breast implant is removed and replaced, often with a new implant type or a change in pocket location. Despite surgical intervention, recurrence is possible.