indirect hernia: an indirect inguinal hernia with two hernia sacs, without a concomitant direct hernia component (as seen in a pantaloon hernia). hiatus hernia: a hernia due to "short oesophagus" — insufficient elongation — stomach is displaced into the thorax littre's hernia: a hernia involving a meckel's diverticulum. it is named after the french anatomist alexis littré (1658–1726). lumbar hernia: a hernia in the lumbar region (not to be confused with a lumbar disc hernia), contains the following entities: petit's hernia: a hernia through petit's triangle (inferior lumbar triangle). it is named after french surgeon jean louis petit (1674–1750). grynfeltt's hernia: a hernia through grynfeltt-lesshaft triangle (superior lumbar triangle). it is named after physician joseph grynfeltt (1840–1913). maydl's hernia: two adjacent loops of small intestine are within a hernial sac with a tight neck. the intervening portion of bowel within the abdomen is deprived of its blood supply and eventually becomes necrotic. obturator hernia: hernia through obturator canal patient with a colostomy complicated by a large parastomal hernia. parastomal hernias, which is when tissue protrudes adjacent to a stoma tract. paraumbilical hernia: a type of umbilical hernia occurring in adults perineal hernia: a perineal hernia protrudes through the muscles and fascia of the perineal floor. it may be primary but usually is acquired following perineal prostatectomy, abdominoperineal resection of the rectum, or pelvic exenteration. properitoneal hernia: rare hernia located directly above the peritoneum, for example, when part of inguinal hernia projects from the deep inguinal ring to the preperitoneal space. retrocolic hernia: entrapment of portions of the small intestine behind the mesocolon. richter's hernia: a hernia involving only one sidewall of the bowel, which can result in bowel strangulation leading to perforation through ischaemia without causing bowel obstruction or any of its warning signs. it is named after german surgeon august gottlieb richter (1742–1812). sliding hernia: occurs when an organ drags along part of the peritoneum, or, in other words, the organ is part of the hernia sac. the colon and the urinary bladder are often involved. the term also frequently refers to sliding hernias of the stomach. sciatic hernia: this hernia in the greater sciatic foramen most commonly presents as an uncomfortable mass in the gluteal area. bowel obstruction may also occur. this type of hernia is only a rare cause of sciatic neuralgia. sports hernia: a hernia characterized by chronic groin pain in athletes and a dilated superficial inguinal ring. tibialis anterior hernia: can present as a bulge in the shins. pain on rest, walking, or during exercise may occur. the bulge can typically not be present unless pressure or flexing of the leg occurs. velpeau hernia: a hernia in the groin in front of the femoral blood vessels treatment main articles: hernia repair and inguinal hernia surgery hernia repair being performed aboard the amphibious assault ship uss bataan. truss the benefits of the use of an external device to maintain reduction of the hernia without repairing the underlying defect (such as hernia trusses, trunks, belts, etc.) are unclear. surgery surgery is recommended for some types of hernias to prevent complications such as obstruction of the bowel or strangulation of the tissue, although umbilical hernias and hiatus hernias may be watched, or are treated with medication. most abdominal hernias can be surgically repaired, but surgery has complications. time needed for recovery after treatment is reduced if hernias are operated on laparoscopically. however, open surgery can be done sometimes without general anesthesia. robot-assisted hernia surgery has also recently gained popularity as safe alternatives to open surgery. uncomplicated hernias are principally repaired by pushing back, or "reducing", the herniated tissue, and then mending the weakness in muscle tissue (an operation called herniorrhaphy). if complications have occurred, the surgeon will check the viability of the herniated organ and remove part of it if necessary. muscle reinforcement techniques often involve synthetic materials (a mesh prosthesis). the mesh is placed either over the defect (anterior repair) or under the defect (posterior repair). at times staples are used to keep the mesh in place. these mesh repair methods are often called "tension free" repairs because, unlike some suture methods (e.g., shouldice), muscle is not pulled together under tension. however, this widely used terminology is misleading, as there are many tension-free suture methods that do not use mesh (e.g., desarda, guarnieri, lipton-estrin, etc.). evidence suggests that tension-free methods (with or without mesh) often have lower percentage of recurrences and the fastest recovery period compared to tension suture methods. however, among other possible complications, prosthetic mesh usage seems to have a higher incidence of chronic pain and can also cause infections. the frequency of surgical correction ranges from 10 per 100,000 (u.k.) to 28 per 100,000 (u.s.). recovery many patients are managed through day surgery centers and are able to return to work within a week or two, though intense activities are prohibited for a longer period. people who have their hernias repaired with mesh often recover within a month, but pain can last longer. surgical complications may include pain that lasts more than three months, surgical site infections, nerve and blood vessel injuries, injury to nearby organs, and hernia recurrence. pain that lasts more than three months occurs in about 10% of people following hernia repair. epidemiology about 27% of males and 3% of females develop a groin hernia at some time in their lives. in 2013 about 25 million people had a hernia. inguinal, femoral and abdominal hernias resulted in 32,500 deaths globally in 2013 and 50,500 in 1990.