Inguinal hernia surgery


Inguinal hernia surgery is an operation to repair a weakness in the abdominal wall that abnormally allows abdominal contents to slip into a narrow tube called the inguinal canal in the groin region.
There are two different clusters of hernia: groin and ventral wall. Groin hernia includes femoral, obturator, and inguinal. Inguinal hernia is the most common type of hernia and consist of about 75% of all hernia surgery cases in the US. Inguinal hernia, which results from lower abdominal wall weakness or defect, is more common among men with about 90% of total cases. In the inguinal hernia, fatty tissue or a part of the small intestine gets inserted into the inguinal canal. Other structures that are uncommon but may get stuck in inguinal hernia can be the appendix, caecum, and transverse colon. Hernias can be asymptomatic, incarcerated, or strangled. Incarcerated hernia leads to impairment of intestinal flow, and strangled hernia obstructs blood flow in addition to intestinal flow.
Inguinal hernia can make a small lump in the groin region which can be detected during a physical exam and verified by imaging techniques such as computed tomography. This lump can disappear by lying down and reappear through physical activities, laughing, crying, or forceful bowel movement. Other symptoms can include pain around the groin, an increase in the size of the bulge over time, pain while lifting, and a dull aching sensation. In occult hernia, the bulge cannot be detected by physical examination and magnetic resonance imaging can be more helpful in this situation. Males who have asymptomatic inguinal hernia and pregnant women with uncomplicated inguinal hernia can be observed, but the definitive treatment is mostly surgery.
Surgery remains the ultimate treatment for all types of hernias as they will not get better on their own, however not all require immediate repair. Elective surgery is offered to most patients taking into account their level of pain, discomfort, degree of disruption in normal activity, as well as their overall level of health. Emergency surgery is typically reserved for patients with life-threatening complications of inguinal hernias such as incarceration and strangulation. Incarceration occurs when intra-abdominal fat or small intestine becomes stuck within the canal and cannot slide back into the abdominal cavity either on its own or with manual maneuvers. Left untreated, incarceration may progress to bowel strangulation as a result of restricted blood supply to the trapped segment of small intestine causing that portion to die. Successful outcomes of repair are usually measured via rates of hernia recurrence, pain and subsequent quality of life.
Surgical repair of inguinal hernias is one of the most commonly performed operations worldwide and the most commonly performed surgery within the United States. A combined 20 million cases of both inguinal and femoral hernia repair are performed every year around the world with 800,000 cases in the US as of 2003. The UK reports around 70,000 cases performed every year. Groin hernias account for almost 75% of all abdominal wall hernias with the lifetime risk of an inguinal hernia in men and women being 27% and 3% respectively. Men account for nearly 90% of all repairs performed and have a bimodal incidence of inguinal hernias peaking at 1 year of age and again in those over the age of 40. Although women account for roughly 70% of femoral hernia repairs, indirect inguinal hernias are still the most common subtype of groin hernia in both males and females.
Inguinal hernia surgery is also one of the most common surgical procedures, with an estimated incidence of 0.8-2% and increasing up to 20% in preterm children.

Indications for surgery

Surgical intervention for hernias is guided by various factors, including the severity of symptoms, hernia type, medical history, hernia size, bowel incarceration and the overall general health of the person.

Non-urgent repair

is planned in order to help relieve symptoms, respect the person's preference, and prevent future complications that may require emergency surgery.
Surgery is offered to the majority of people who:
  • have symptoms that interfere with their normal level of activity.
  • have hernias that become increasingly difficult to reduce.
  • are female as it is often difficult to classify the subtype of hernia based on an exam alone.
Symptomatic hernias tend to cause pain or discomfort within the groin region that may increase with exertion and improve with rest. A swollen scrotum within males may coincide with persistent feelings of heaviness or generalized lower abdominal discomfort. The sensation of groin pressure tends to be most prominent at the end of the day as well as after strenuous activities. Changes in sensation may be experienced along the scrotum and inner thigh.

Urgent repair

A hernia in which the small intestine has become incarcerated or strangulated constitutes a surgical emergency. Symptoms include:
  • Fever
  • Nausea and vomiting
  • Extreme pain in the area of the hernia
  • Warm hernia bulge with surrounding skin redness
  • Can no longer pass gas or stool
Surgical repair within 6 hours of the above symptoms may be able to save the strangulated portion of the intestine.
Although pediatric inguinal hernias sometimes present asymptomatically, surgical repair is still the standard of care to prevent hernia incarceration, which for children who are born with hernias has a risk of 12% in full-term children and 39% in preterm children. In preterm neonates, the timing for intervention appears to be of utter importance as surgical hernia repair after neonatal intensive care unit discharge might decrease recurrence and anesthesia-induced respiratory difficulties compared to surgery before NICU discharge.

Contraindications to surgery

The person with the hernia should be given an opportunity to participate in the shared decision-making with their physicians as almost all procedures carry significant risks. The benefits of inguinal hernia repair can become overshadowed by risks such that elective repair is no longer in a person's best interest. Such cases include:
Additionally, certain medical conditions can prevent people from being candidates for laparoscopic approaches to repair. Examples of such include:
  • People who are unable to undergo general anesthesia
  • Prior major open abdominal surgery
  • People who have ascites
  • Previous radiation therapy to the pelvis
  • A complex hernia

    Surgical approaches

Techniques to repair inguinal hernias fall into two broad categories termed "open" and "laparoscopic". Surgeons tailor their approach by taking into account factors such as their own experience with either techniques, the features of the hernia itself, and the person's anesthetic needs.
The cost associated with either approach varies widely across regions, but updated guidelines published by the International Endohernia Society cast doubt on the comprehensiveness of cost comparison studies due in part to the complexity inherent in calculating costs across institutions. The IES asserts that hospital and societal costs are lower for laparoscopic repairs as compared to open approaches. They recommend the routine use of reusable instruments as well as improving the proficiency of surgeons to help further decrease costs as well as time spent in the OR. However, as an example, the UK's National Health Service spends £56 million a year in repairing inguinal hernias, 96% of which were repaired via the open mesh approach while only 4% were done laparoscopically.

Open hernia repair

All techniques involve an approximate 10-cm incision in the groin. Once exposed, the hernia sac is returned to the abdominal cavity or excised and the abdominal wall is very often reinforced with mesh. There are many techniques that do not utilize mesh and have their own situations where they are preferable.
Open repairs are classified via whether prosthetic mesh is utilized or whether the patient's own tissue is used to repair the weakness. Prosthetic repairs enable surgeons to repair a hernia without causing undue tension in the surrounding tissues while reinforcing the abdominal wall. Repairs with undue tension have been shown to increase the likelihood that the hernia will recur. Repairs not using prosthetic mesh are preferable options in patients with an above-average risk of infection such as cases where the bowel has become strangulated.
One large benefit of this approach lies in its ability to tailor anesthesia to a person's needs. People can be administered local anesthesia, a spinal block, as well as general anesthesia. Local anesthesia has been shown to cause less pain after surgery, shorten operating times, shorten recovery times as well as decrease the need to return to the hospital. However, people who undergo general anesthesia tend to be able to go home faster and experience fewer complications. The European Hernia Society recommends the use of local anesthesia particularly for people with ongoing medical conditions.

Open mesh repairs

Repairs that utilize mesh are usually the first recommendation for the vast majority of patients including those that undergo laparoscopic repair. Procedures that employ mesh are the most commonly performed as they have been able to demonstrate better results compared to non-mesh repairs. Approaches utilizing mesh have been able to demonstrate faster return to usual activity, lower rates of persistent pain, shorter hospital stays, and a lower likelihood that the hernia will recur.
Options for mesh include either synthetic or biologic. Synthetic mesh provides the option of using "heavyweight" as well as "lightweight" variations according to the diameter and number of mesh fibers. Lightweight mesh has been shown to have fewer complications related to the mesh itself than its heavyweight counterparts. It was additionally correlated with lower rates of chronic pain while sharing the same rates of hernia recurrence as compared to heavyweight options. This has led to the adoption of lightweight mesh for minimizing the chance of chronic pain after surgery. Biologic mesh is indicated in cases where the risk of infection is a major concern such as cases in which the bowel has become strangulated. They tend to have lower tensile strength than their synthetic counterparts lending them to higher rates of mesh rupture.
Biomeshes are increasingly popular since their first use in 1999 and their subsequent introduction to the market in 2003. Some have a similar price to high end synthetic meshes. They can be produced from absorbable, animal-sourced extra cellular matrix, or by other means. Synthetic absorbable meshes are also available.
Meshes made of mosquito net cloth, in copolymer of polyethylene and polypropylene have been used for low-income patients in rural India and Ghana. Each piece costs $0.01, 3700 times cheaper than an equivalent commercial mesh. They give results identical to commercial meshes in terms of infection and recurrence rate at 5 years.