Summary points
How do inguinal hernias present?
Inguinal hernias present with a lump in the groin that goes away with minimal pressure or when the patient is lying down. Most cause mild to moderate discomfort that increases with activity. A third of patients scheduled for surgery have no pain, and severe pain is uncommon (1.5% at rest and 10.2% on movement).
Inguinal hernias are at risk of irreducibility or incarceration, which may result in strangulation and obstruction; however, unlike with femoral hernias, strangulation is rare. National statistics from England identified that 5% of repairs of primary inguinal hernia were emergency operations in 1998-9. Older age and longer duration of hernia and of irreducibility are risk factors for acute complications. Gallegos and colleagues studied the presentation of inguinal hernias with a “working diagnosis of strangulation.” Only 14 of their 22 patients with an acute hernia had compromised tissue at operation, with one of 439 patients requiring bowel resection. Though the study numbers are small, these findings emphasize the rarity of strangulation. A recent larger study estimated the lifetime risk of strangulation at 0.27% for an 18 year old man and 0.03% for a 72 year old man.
How is an inguinal hernia assessed clinically?
A hernia is reducible if it occurs intermittently (such as on straining or standing) and can be pushed back into the abdominal cavity, and irreducible if it remains permanently outside the abdominal cavity. A reducible hernia is usually a longstanding condition, and diagnosis is made clinically, on the basis of typical symptoms and signs. The condition may be unilateral or bilateral and may recur after treatment (recurrent hernia).
Inguinal hernias are often classified as direct or indirect, depending on whether the hernia sac bulges directly through the posterior wall of the inguinal canal (direct hernia) or passes through the internal inguinal ring alongside the spermatic cord, following the coursing of the inguinal canal (indirect hernia) . However, there is no clinical merit in trying to differentiate between direct or indirect hernias. The box outlines important elements in examining patients who have a suspected inguinal hernia.
How can an inguinal hernia be treated?
Surgical options for inguinal hernias
Surgery is the treatment of choice varying from a nylon darn, Should ice layered, Lichtenstein mesh (fig 2?2)) to a laparoscopic repair. The optimal repair has been assessed by randomized clinical trials and population based studies.
Mesh or sutured repair?
A meta-analysis from the EU Hernia Trialists Collaboration compared mesh with sutured techniques from 58 trials comprising in total 11?174 patients. Individual patient data were available for 6901 patients. Recurrence was less common after mesh repair (odds ratio 0.43 (95% confidence interval 0.34 to 0.55)). A population based study examining risk of recurrence five years or more after primary mesh (Lichtenstein repair) and sutured inguinal hernia repair in 13?674 patients found that recurrence after mesh repair was a quarter of that after sutured repair (hazard ratio 0.25 (0.16 to 0.40)).
Open mesh repair is reproducible by non-specialist surgeons, and hence open repair is the preferred repair technique for primary inguinal hernia (by 96% of UK surgeons, 99% of Japanese surgeons, 95% of Danish surgeons, and 86% of US surgeons.
Open or laparoscopic repair?
Systematic review and meta-analysis of randomized clinical trials have found that, compared with open repair, laparoscopic surgery for hernia is associated with longer operation times but less severe postoperative pain, fewer complications, and a more rapid return to normal activities. Laparoscopic surgery is associated with higher recurrence rates during the learning curve but causes less chronic pain and numbness when assessed by questionnaire up to five years after operation. The National Institute for Health and Clinical Excellence (NICE) recently recommended laparoscopic surgery as a treatment option for inguinal hernia and said that patients should be fully informed of the risks and benefits of open and laparoscopic surgery to enable them to choose between procedures.
Local, general, or regional anesthesia?
A recent, Swedish, multicenter trial randomized patients to receive local infiltration anesthesia, regional anesthesia, or general anesthesia for repair of inguinal hernia in non-specialist centers. The trial found a significant advantage with local infiltration anesthesia, which was associated with a shorter hospital stay, less severe postoperative pain, and fewer micturition difficulties.15 Significantly reduced overall costs were found with local anesthesia owing to shorter total time in theatre, earlier discharge, and equipment requirements.
Other studies report similar results but with less pronounced differences. This may be the result of a lack of standardization of general anesthesia in the Swedish study. Many countries, however, still use general or regional anesthesia for hernia repair, with a minority using local anesthesia. A recent study in Denmark of 57?505 elective open groin (mainly inguinal) hernia operations found that 64% were via general anesthetic, 18% regional anesthetic, and 18% local anesthetic. Regional anesthesia gives the poorest results and probably has little role in modern inguinal hernia surgery. Poor uptake of local anesthesia may relate to surgical tradition, surgeon preference, inadequate technical proficiency, and little incentive for cost effective techniques.
