A hernia is the protrusion of an organ or tissue through a weak spot in the muscle or fascia, such as the abdominal wall. This defect allows internal contents to bulge outward, often visible as a lump under the skin. The primary goal of a surgical repair is to return these contents to their proper position and then strengthen the weakened area. The specific contents of the hernia sac determine the surgical approach, particularly regarding the handling of any fatty tissue found during the procedure.
Understanding Hernia Contents
The contents that push through the abdominal wall defect are typically structures from the abdominal cavity. While the intestine is a concern, the most common material found in a hernia sac is fatty tissue. This fat is not the subcutaneous fat found just beneath the skin, nor is its removal related to cosmetic liposuction.
The fatty tissue encountered is usually either the omentum or pre-peritoneal fat. The omentum is a large, apron-like sheet of fatty tissue that hangs down from the stomach and covers the intestines. Pre-peritoneal fat is the layer of adipose tissue located between the inner lining of the abdominal wall (the peritoneum) and the muscle layer. This pre-peritoneal fat is particularly common in inguinal hernias, sometimes being the sole content of the sac.
The Surgical Handling of Protruding Tissue
The standard procedure for managing the contents of a hernia sac is called reduction. This involves carefully pushing the contents, whether bowel or fatty tissue, back into the abdominal cavity through the defect. Reduction is the preferred method for any tissue that is healthy and viable, meaning it has a good blood supply and is not damaged.
In a routine, uncomplicated hernia repair, the surgeon gently manipulates the viable omentum or pre-peritoneal fat back inside the abdomen. This maneuver clears the hernia opening so the surgeon can effectively close the defect and place a reinforcing mesh if needed. The objective is to preserve and restore the displaced tissue, as the omentum serves protective functions. If the tissue is healthy, it is simply repositioned, not removed.
Why Surgeons Sometimes Remove Omental Fat
The decision to remove fatty tissue, specifically the omentum, is made only when certain complications or anatomical challenges are present. This removal is technically referred to as a partial omentectomy.
One of the most urgent reasons for removal is non-viability or strangulation, which occurs when the hernia defect pinches the tissue so tightly that the blood supply is cut off. If the omental fat is ischemic (lacking blood flow) or necrotic (dead), it must be excised to prevent severe infection within the abdominal cavity. In these emergency situations, the compromised tissue poses a much greater risk than its removal.
The second common reason for a partial omentectomy is if the omentum is excessively bulky, inflamed, or densely adhered to the hernia sac or surrounding tissues. Such bulkiness or dense adhesion can make safe reduction back into the abdomen difficult or impossible without causing significant tension or damage.
In patients with a higher body mass index, the omentum and pre-peritoneal fat pads can be thicker. This thickness sometimes interferes with the closure of the abdominal wall defect or the proper placement of the surgical mesh. Removing a portion of the fat helps ensure a successful, tension-free repair and minimizes the risk of the hernia returning.