The region of the hernia repair is commonly affected by hardness, swelling and bruising which are related to the clotted blood and fluid under the wound, the stitches pulling the wound together and finally by scar tissue formation. These difficulties all settle over time as the area heals. The genitals can be affected by bruising and then they can become black and blue. This is because downwards is the obvious direction for any bleeding to track after the hernia repair.
Sometimes bruising can be very extensive. Occasionally bleeding from a small blood vessel under the skin or near the repair can produce a collection of blood, visible as a bulge under the wound, called a haematoma. This may settle slowly on its own but sometimes needs to be let out by a further operation. If bleeding spreads down into the scrotum some swelling may remain around the testicle for a long time.
During the operation a small nerve which travels across the incision line may be cut through, causing a minor area of numb feeling at the inner end of the incision. To do the operation well this nerve has to be cut but because the numb area gets smaller with time and is hidden under the pubic hair it does not normally cause any problems. A chronic pain problem over the area of the repair can develop in one in twenty patients and can be a significant problem. Nerve stretch as the operation is being done or the nerve becoming tethered as the healing proceeds are possible reasons for this pain. A pain killer can be injected into the painful area to reduce the pain but in some cases the surgeon will need to re-explore the area to find the trapped nerve and release it.
There is the possibility of damage during the operation to structures around the hernia, the artery, tube to the testicle and the vein. These risks are greater when surgery is done for a recurrent hernia. The testicle can lose its blood supply and shrivel and require removal, and if the tube to the testicle is damaged it will mean the other testicle will need to maintain fertility. This is usually very possible. Removal of the testicle in older patients may be advised routinely by surgeons who are repairing a recurrent hernia and want the best outcome.
Infection of the wound is a risk but is uncommon. If the wound starts to become red then antibiotics may be needed. If pus starts to come out then the wound may need to be opened up to release the infection. Infection increases the chance of a hernia coming back. If the mesh becomes infected another operation may be needed to remove it and the hernia will then need to be repaired again later on. Deep vein thrombosis (DVT) is a possible problem after hernia repair but is rare. If the patient is at particular risk then special precautions will be taken to reduce the risk. Moving the legs and feet as soon as possible after the operation and walking about early all help to stop thrombosis occurring.
The chances of a hernia happening again are less than once in twenty cases after the first repair of a hernia. To have a general anaesthetic involves some risk and this is greater if the patient is suffering from a longstanding medical illness or disease. Short term side effects with the frequency of one in ten to a hundred are blurred vision, pain over the site of injection, bruising and sickness. These are easily managed and do not persist for long.
Less common complications with a frequency 1 in 100 to 10,000 cover pains in the muscles, damage to the lips, teeth or tongue, headaches, temporary problems with speaking, sore throat and short term breathing difficulties. Serious and very rare complications with a frequency of less than 1 in 10,000 cover kidney and liver failure, long term nerve or blood vessel damage, damage to the lungs, eye injury, voice box damage, brain damage, severe allergy reactions and death. The rarity of these complications means that the frequency depends on co-existing medical problems.