User:Averstumor/sandbox



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.

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. Patients who experience little to no symptoms are often advised to remain vigilant as the benefit of surgery may be outweighed by the risks of undergoing an operation. 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.

Indications for surgery
Society guidelines recommend that indications for surgery take into account the severity of symptoms, the type of hernia, previous surgeries, hernia size, bowel incarceration and the overall general health of the patient.

Non-urgent repair
Elective surgery is planned in order to help relieve symptoms, respect patient preference and prevent future complications that may require emergency surgery.

Surgery is offered to the majority of patients in whom: 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.
 * symptoms interfere with their normal level of activity
 * hernias that become increasingly difficult to reduce
 * in females as it is often difficult to classify the subtype on exam alone.

Urgent repair
A hernia in which the small intestine has become incarcerated or strangulated constitutes a surgical emergency. Symptoms include: Surgical repair within 6 hours of the above symptoms may be able to save the strangulated portion of intestine.
 * 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

Contraindications to surgery
As with all medical interventions, patients should engage in 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 patient's best interest. Such cases include: Additionally, certain medical conditions can prevent patients from being candidates for laparoscopic approaches to repair. Examples of such include:
 * Patients with unstable medical conditions
 * Repair using mesh is withheld in patients who have active infections within the groin or within the blood stream
 * Elective repair is delayed in pregnant women until 4 weeks after delivery
 * Patients unable to undergo general anesthesia
 * Prior major open abdominal surgery
 * Patients with ascites
 * Previous radiation therapy to the pelvis
 * Patients with a complex hernia

Historical evolution
Some of the earliest accounts of hernias and their treatment come from the ancient Egyptians employing trusses and surgery in order to address painful symptoms. The Greek era introduced the reduction of hernias in which manual maneuvers are utilized in order to return bowel into the abdomen. As operations to repair hernias continued to evolve, it remained common practice to castrate males during repairs throughout the middle ages. Swift surgeries were necessitated as modern anesthesia had yet to develop. In 1543, large advances in modern anatomy provided by the works of Andreus Vesalius allowed surgeons a more anatomy-driven approach to the repair of hernias. Ambrose Pare made large contributions to the field of surgery in particular to his description of hernia repair. He employed a method whereby intestine was reduced back into the abdomen, the remnant sack was removed, and the abdominal lining was subsequently repaired.

Surgical approaches
Techniques to repair inguinal hernias fall into two broad categories termed "open" and "laparoscopic". Surgeons tailor their approach to each patient by taking into account factors such as their own experience with either techniques, the features of the hernia itself, and the patient's anesthetic needs.

The cost associated with either approach varies widely across regions. As an example the UK's NHS 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. The cost associated with either technique has been studied by many countries and their respective hernia societies. Most have been able to show that open hernia repair provides the most value-to-cost as compared to laparoscopic repairs. Factors such as the use of disposable surgical products, cost of addressing complications, as well as overall time spent in the operating room were examined in such studies. In contrast, updated guidelines published by the International Endohernia Society cast doubt on the comprehensiveness of such studies due in part to the complexity inherent in calculating costs across institutions. The IES asserts that hospital and societal costs are in fact 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.

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 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 wether 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 it's ability to tailor anesthesia to the patients needs. Patients can be administered local anesthesia, a spinal block, as well as general anesthesia. Local anesthesia has been shown to cause less pain after surgery, shorter operating times, shorter recovery times as well as decrease the need for patients to go back to the hospital. However, patients who undergo general anesthesia tend to be able to go home faster and experience fewer complications. The European Hernia Society recommends local anesthesia particularly for patients 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 greater results as 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 it's 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 on the market in 2003. Some meshes have a price comparable to the high end of synthetic meshes, the cheapest ($500) being Surgisis-Biodesign, manufactured by Cook Group, made from the extra cellular matrix of pig small intestinal submucosa. Currently, there exists one synthetic totally absorbable mesh, Tigr Matrix, manufactured by Novus Scientific, on the US market (510(k) Food and Drug Administration clearance) since 2010 and on the EU market since 2011. It only has one 3-year pre-clinical evidence on sheep.

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.

Lichtenstein technique
The Lichtenstein tension-free repair has persisted as one of the most commonly performed procedures in the world. The European Hernia Society recommends that in cases where an open approach is indicated, the Lichtenstein technique be utilized as the preferred method. Recent studies have indicated that mesh attachment with the use of adhesive glue is faster and less likely to cause post-op pain as compared to attachment via suture material.

Plug and patch technique
The plug and patch tension-free technique has fallen out of favor due to higher rates of mesh shift along with its tendency to irritate surrounding tissue. This has led to the European Hernia Society recommending that the technique not be used in most cases.

Other open mesh repair techniques
A variety of other tension-free techniques have been developed and include:
 * Prolene mesh system (PHS)
 * Kugel (preperitoneal repair)
 * Stoppa
 * Trabucco (Hertra mesh)
 * Wantz
 * Rutkow/Robbins

Open non-mesh repairs
Techniques in which mesh is not used are referred to as tissue repair technique, suture technique, and tension technique. All involve bringing together the tissue with sutures and are a viable alternative when mesh placement is contraindicated. Such situations are most commonly due to concerns of contamination in cases where there are infections of the groin, strangulation or perforation of the bowel.

Shouldice technique
The Shouldice technique is the most effective non-mesh repair thus making it one of the most commonly utilized methods. Numerous studies have been able to validate the conclusion that patients have lower rates of hernia recurrence with the Shouldice technique as compared to other non-mesh repair techniques. However this method frequently experiences longer procedure times and length of hospital stay. Despite being the superior non-mesh technique, the Shouldice method results much higher rates of hernia recurrence in patients when compared to repairs that utilize mesh.

Bassini technique
The first efficient inguinal hernia repair was described by Edoardo Bassini in the 1880s. In the Bassini technique, the conjoint tendon (formed by the distal ends of the transversus abdominis and internal oblique muscles) is approximated to the inguinal ligament and closed.

Other open non-mesh techniques
The Shouldice technique was itself an evolution of prior techniques that had greatly advanced the field of inguinal hernia surgery. Such classic open non-mesh repairs include:
 * McVay technique
 * Halsted
 * Maloney darn
 * Plication darn

Laparoscopic repair
There are two main methods of laparoscopic repair: transabdominal preperitoneal (TAPP) and totally extra-peritoneal (TEP) repair. When performed by a surgeon experienced in hernia repair, laparoscopic repair causes fewer complications than Lichtenstein, particularly less chronic pain. However, if the surgeon is experienced in general laparoscopic surgery but not in the specific subject of laparoscopic hernia surgery, laparoscopic repair is not advised as it causes more recurrence risk than Lichtenstein while also presenting risks of serious complications, as organ injury. Indeed, the TAPP approach needs to go through the abdomen. All that said, many surgeons are moving to laparoscopic methodologies as they cause smaller incisions, resulting in less bleeding, less infection, faster recovery, reduced hospitalization, and reduced chronic pain. There is no difference in cost between laparoscopic and open repair as the increased costs of operation are offset by the decreased recovery period. Recurrence rates are identical when laparoscopy is performed by an experienced surgeon. When performed by a surgeon less experienced in inguinal hernia lap repair, recurrence is larger than after Lichtenstein.

Non-surgical management
Studies have demonstrated that men whose hernias cause little to no symptoms can safely continue to delay surgery until a time that is most convenient for patients and their healthcare team. Research shows that the risk of inguinal hernia complications remains under 1% within the population. Watchful waiting requires that patients maintain a close follow-up schedule with providers to monitor the course of their hernia for any changes in symptoms and can be safely offered for up to 2 years.

Patients who do elect watchful waiting eventually undergo repair within five years as 25% will experience a progression of symptoms such as worsening of pain. Elective repair discussions should be revisited if patient's begin to avoid aspects of their normal routine due to their hernia. After 1 year it is estimated that 16% of patients who initially opted for watchful waiting will eventually undergo surgery. Furthermore 54% and 72% will undergo repair at 5-year and 7.5-year marks respectively.

The use of a truss is an additional non-surgical option for men. It resembles a jock-strap that utilizes a pad to exert pressure at the site of the hernia in order prevent excursion of the hernia sack. It has little evidence to support its routine use and has not been shown to prevent complications such as incarceration or strangulation of bowel. However some patients do report a soothing of symptoms when utilized.

Complications and prognosis
Inguinal hernia repair complications are unusual and the procedure as a whole proves to be relatively safe for the majority of patients. Risks inherent in almost all surgical procedures include: Risks that are specific to inguinal hernia repairs include such things as: Post-herniorrhaphy inguinodynia is a condition where 10-12% of patients experience severe pain after inguinal hernia repair. The mechanism of which remains a complex combination of different forms of pain signals. It can occur with any inguinal hernia repair technique and if unresponsive to pain medications, further surgical intervention is often required. Removal of mesh in combination with bisection of regional nerves is commonly performed to address such cases. There remains ongoing discussion amongst surgeons regarding the utility of planned resections of regional nerves as an attempt to prevent its occurrence.
 * bleeding
 * fluid collections
 * infection
 * damage to surrounding structures such as vessels, nerves and organs
 * urinary retention requiring a catheter
 * injury to the bladder
 * injury to nearby nerves
 * in males, injury to the tube that conveys sperm from the testicle to the penis
 * Genital or ejaculatory pain or impairment of sexual activity
 * in males, bruising and swelling of the scrotum
 * recurrence of the hernia
 * chronic regional pain
 * also known as Post-herniorrhaphy inguinodynia or Chronic postoperative inguinal pain

Mortality rates for non-urgent, elective procedures was demonstrated as 0.1% and around 3% for procedures performed urgently. Other than urgent repair, risk factors that were also associated with increased mortality included being female, requiring a femoral hernia repair, and older age.

Follow-up
Upon awakening from anesthesia, patients are monitored for their ability to drink fluids, produce urine, as well as their ability to walk after surgery. Most patients are then able to return home once those conditions are met. It is not uncommon for patients to experience residual soreness for a couple of days after surgery. Patients are encouraged to make strong efforts in getting up and walking around the day after surgery. Most patients can resume their normal routine of daily living within the week such as driving, showering, light lifting, as well as sexual activity. Long work absences are rarely necessary and length of sick days tend to be dictated by respective employment policies.

Post-op development of any of the following should warrant timely reporting via phone:
 * fever greater than 39C/101F
 * progressive swelling of the surgical site
 * severe pain
 * recurring nausea or vomiting
 * worsening redness around incisions
 * drainage of pus from incisions
 * difficulty or lack of producing urine
 * new-onset shortness of breath

Prevention and screening
Most indirect inguinal hernias in the abdominal wall are not preventable. Direct inguinal hernias may be able to be prevented by maintaining a healthy weight, refraining from smoking, preventing bowel straining during bowel movements, and maintaining proper lifting techniques when heavy lifting. There is no evidence that indicates physicians should routinely screen for asymptomatic inguinal hernias during patient visits.