Groin pain after inguinal hernia surgery is not uncommon regardless of the type of repair, which includes laparoscopic, robotic, open, mesh, and no mesh repairs.
There are three main nerves that run in the inguinal canal, which are the ilioinguinal nerve, iliohypogastric nerve, and the genital branch of the genital femoral nerve; and any one of these nerves can cause significant pain in the groin if not appropriately identified and protected during the surgery. Often one of the nerves will be stretched by the hernia sac or more commonly adhere to the mesh from the repair. Once the mesh adheres to the nerve, every time the person twists, turns, or moves in a certain direction, severe electrical pain can occur. This is because the nerve needs to be mobile and not tethered. If this pain does not resolve within several weeks of the surgery, one can assume that the nerves are scarred or injured. Often patients will be placed on chronic pain medications which usually have little effect in controlling the pain.
It is important to recognize this problem and know that there is a surgical option to treat the pain. This starts by having a surgeon who can recognize the source of pain. The exam begins by trying to isolate the maximal area of pain in the groin crease with one finger as this is the most likely location of the pain. Once this area has been identified by the surgeon and patient, a nerve block is performed by injecting a local anesthetic into this area. The purpose of the nerve block is to numb the injured nerve with hopes of removing the pain for a period of time. A successful nerve block will result in a significant reduction or compete resolution of pain within 5-10 minutes. This block will often only be short acting but gives the patient and surgeon an idea of what can be expected from a groin denervation surgery.
The surgery would then be carried out in a different setting through an incision in the groin crease. This can be through the scar if an open approach was used during the initial surgery. The surgery would require opening the entire inguinal floor to allow careful identification of the 3 nerve branches. This requires a skilled microsurgeon with experience locating these nerves as they are 1mm or smaller in size. If the nerve appears normal, then it can be preserved; however, if it is scarred or injured, it will need to be removed. Reconstruction of the nerves is not usually possible due to the small caliber of the nerve. Therefore, the nerves are often trimmed back; thereby, allowing them to fall into the deep plane of muscle or the abdominal cavity. The overall goal is to remove each nerve from the mesh or scar tissue and potentially elevating most if not all of the pain.
After the surgery patients can expect numbness in the inguinal area and groin crease. Patients usually welcome the loss of sensation in the groin if the pain is gone as well. It is important to point out that even though one of the nerves is called the genital branch, it does not innervate the genitals. So, removing it does not affect sexual function or sensation of the external genitalia since that is innervated by the pudendal nerve.
Groin denervation can be very successful but needs to be carried out by a skilled microsurgeon. The skill set to identify the nerves is not commonly found in even the best general surgeons or hernia surgeons.