1 Clinical Anatomy

Flank hernias can be divided broadly by etiology into those that are congenital in nature and those that are acquired, often after previous surgery or trauma. Congenital, or lumbar hernias, are less common than the acquired type and can be subclassified into superior triangle (Grynfeltt) or inferior triangle (Petit) defects. Acquired flank hernias can develop after previous operations such as iliac bone harvest, trauma, retroperitoneal aortic surgery, or nephrectomy. The anatomic proximity of flank hernias to bony prominences and major neurovascular structures presents a challenge in the durable repair of these hernias. Specifically, the proximity of these lesions with the iliac crest and twelfth rib can often limit the amount of tissue present for adequate mesh-tissue overlap.

2 Preoperative Considerations

When considering surgical repair of flank hernias, it is important to perform a computed tomography (CT) scan of the abdomen and pelvis. First and foremost, this will distinguish a true hernia from a pseudohernia (e.g., abdominal wall laxity from denervation after division of the lower thoracic nerves). In addition, a CT scan is not only essential to understanding the patient’s specific anatomy but also for delineating the presence of previous mesh repairs. It also will show the structure of remaining bone, because there may be alterations secondary to previous operations in this area. This information is important for planning the appropriate location for prosthetic deployment and any fixation or overlap issues that might arise.

Preoperative counseling detailing the risks of nerve injury leading to numbness, weakness, or chronic pain, as well as the risks for vascular and intraabdominal injury is important.

Given the large incision and extent of dissection, these patients may benefit from the placement of preoperative epidurals for postoperative pain management if no other contraindications exist. Routine preoperative antibiotics for skin flora should be administered.

3 Operative Steps

1 Patient Positioning

The patient is positioned in the full lateral decubitus position on a beanbag as seen in Figure 6-1. A roll is placed in the axilla and the table is flexed to maximize the space between the lower border of the costal margin and the anterior superior iliac spine to optimize exposure. The beanbag is then engaged for support and padding. The patient should be secured to the table with padded tape to allow for full rotation of the bed during the operation.