Incisional hernias, a common complication following abdominal surgery, present a significant challenge in surgical repair. Understanding the abdominal wall musculature, particularly Where Is Oblique Muscle located and its function, is crucial for comprehending the complexities of hernia development and effective repair strategies. This article delves into the role of the oblique muscles in the context of incisional hernias, drawing upon research that highlights the myopathic changes these muscles undergo during hernia formation and their impact on surgical outcomes.
The abdominal wall is composed of several muscle layers, including the external oblique, internal oblique, transversus abdominis, and rectus abdominis. The oblique muscles, specifically the external and internal obliques, are located on the anterolateral aspect of the abdomen. The external oblique is the outermost layer, running inferomedially, while the internal oblique lies beneath it, running superomedially, roughly perpendicular to the external oblique. These muscles play a critical role in trunk rotation, lateral flexion, and maintaining abdominal wall tension and support. They are essential for core stability and contribute significantly to the structural integrity of the abdominal wall.
Research using rat models of incisional hernia formation has revealed significant changes in the internal oblique muscle during herniation. Studies have shown that when midline laparotomy incisions fail and develop into incisional hernias, the internal oblique muscles undergo atrophy. This atrophy is characterized by a shift in muscle fiber type composition, a reduction in the cross-sectional area of muscle fibers, and the development of pathological fibrosis, indicative of disuse myopathy. These changes are not merely structural; they have a profound impact on the mechanical properties of the muscle. Atrophied oblique muscles exhibit decreased extensibility and increased stiffness, altering the biomechanics of the abdominal wall.
The consequences of oblique muscle atrophy extend to the success of incisional hernia repair. The fibrotic and stiffened oblique muscles reduce the overall compliance of the abdominal wall. This decreased compliance means that when a hernia is repaired, the forces are disproportionately transferred to the midline wound closure. Research demonstrates that hernia repairs in models with chronic hernias and associated oblique muscle myopathy are mechanically weaker and fail at lower forces compared to repairs in non-herniated abdominal walls. This suggests that the pathological changes in the oblique muscle contribute to the higher recurrence rates observed in incisional hernia repairs.
In conclusion, the oblique muscles, located on the flanks of the abdomen and crucial for abdominal wall strength, are significantly affected by incisional hernia formation. The atrophy and fibrotic changes in these muscles are not just a consequence of hernia development but also a contributing factor to the challenges in hernia repair. Understanding the location and pathological changes in the oblique muscle is therefore vital for developing improved surgical techniques and strategies to enhance the long-term success of incisional hernia repairs.
