Complex disruptions in wound healing, collagen remodeling, and tissue mechanics may underlie incisional hernia beyond surgical technique alone, according to a review of abdominal wall structural biology and biomechanics published in the International Journal of Tissue Repair and Regeneration.
Incisional hernia (IH), a condition in which abdominal contents protrude through a weakened surgical scar, remains a frequent complication following abdominal surgery — with recurrence rates reaching as high as 32% even after repair. The condition affects an estimated 5% to 20% of patients after abdominal procedures, depending on patient factors and surgical circumstances. In severe cases, complications such as bowel obstruction or strangulation can become life-threatening, according to the study.
The authors noted that incisional hernias may represent a failure of wound healing rather than simply a technical complication of surgery.
“IH development is primarily attributed to failure in the wound healing process,” the study reads, emphasizing that biological and biomechanical factors are likely key drivers of scar weakness.
The abdominal wall itself is a layered structure composed of skin, subcutaneous tissue, connective fascia, and the linea alba, which is a collagen-rich midline structure responsible for maintaining abdominal strength under pressure. Surgical incisions disrupt these layers, and the success of healing depends on how well tissues recover their structural integrity.
The review highlighted the importance of collagen organization within the linea alba, where mechanical forces generated by coughing, lifting, and other daily activities can reach substantial levels. Under normal conditions, the structure’s collagen fibers distribute these stresses efficiently. However, alterations in collagen composition may weaken the tissue. Studies have shown that patients with IH often exhibit changes in the balance between collagen types I and III, potentially reducing tensile strength and increasing susceptibility to herniation.
“Histological analyses of IH scars consistently reveal increased type III collagen, leading to a decreased type I/III ratio,” the authors noted. Such changes can produce scar tissue that is mechanically inferior to healthy abdominal fascia.
The wound healing process itself also contributes to vulnerability. During the early postoperative period, an incision regains only a small fraction of its normal strength. The authors reported that “the incision has less than 5% of normal tissue strength during the first 7 days post-laparotomy,” making surgical technique and suture stability critical during this phase.
Beyond collagen abnormalities, the review introduced another possible contributor to hernia development: mineralization within scar tissue. Surgeons have reported observing hardened, discolored tissue during hernia repairs, suggesting abnormal calcium deposition.
The researchers concluded that understanding IH will require a broader, interdisciplinary approach involving surgery, materials science, and advanced imaging techniques. Future investigations may focus on identifying molecular signals that regulate collagen remodeling, detecting abnormal scar development earlier, and designing surgical materials that better mimic the natural mechanical properties of the abdominal wall.
“IH remain a common and complex complication of abdominal surgery, underpinned by an interplay of mechanical disruption, altered wound healing, collagen dysregulation and, potentially, pathological tissue mineralization,” they wrote.
Source: International Journal of Tissue Repair and Regeneration
