Posted on 31 May 2009 17:08
By Robert J. Fitzgibbons Jr.,MD FACS
Harry E. Stuckenhoff Professor of Surgery
Chief of the Division of General Surgery and
Associate Chairman, Department of Surgery
Creighton University School of Medicine
The human body is divided into various compartments such as the thorax (chest), abdomen, skull, etc. The word hernia is derived from the Latin word for "rupture," and occurs when an organ normally contained in one of these cavities protrudes through the lining of that cavity. The term hernia is therefore very broad, as hernias can occur almost anywhere in the body. For example, a protrusion of an intervertebral disk of the spine into the spinal canal is called a herniated or ruptured disk; a protrusion of brain tissue, usually because of a head injury, through a natural opening at the base of the skull (called the foramen occipitalis) is referred to as an Uncal hernia. However the vast majority of hernias involve the abdominal cavity and therefore this article will concentrate specifically on this type of hernia.
Hernia repair is one of the most common operations performed in all of surgery. According to the National Center for Health Statistics over 1,250,000 hernia repair surgeries were performed in 1996 alone. To place this number in perspective, other common operations are listed in table 1. Hernias that involve the abdominal wall are the most common type that cause patients to seek treatment.
Table 1: General Surgical Procedures in the United States
|Inginal hernia repair||777,000|
|Laparoscopic inguinal hernia repair||115,000|
|Implantable vascular access device placement||223,000|
|Table 1: 1|
What is an abdominal wall hernia?
An abdominal wall hernia is present when there is a hole in the lining and muscles of the abdominal wall which allows contents normally contained in the abdomen to protrude outside of the cavity. These hernias have three parts: 1) a neck, which is the hole in the abdominal wall, 2) a sac, which is formed by the protrusion of the lining of the cavity through the hole, and 3) contents, which are any abdominal organ(s) which have protruded through the neck into the hernia sac.
Where do abdominal wall hernias occur?
Approximately 75% of all abdominal wall hernias occur in the groin area and are called inguinal hernias (Figure 1, D-F). The navel is the second most common location and these are called umbilical hernias (Figure 1, C). The next most common hernia develops where the abdomen has been weakened by a previous surgical procedure (Figure 1, B). These are called incisional or ventral hernias. Epigastric hernias occur in the middle of the upper part of the abdomen, along a narrow strip of tissue that connects the two rectus muscles, known as the linea alba (Figure 1, A).
Hernias can also occur through the opening in the diaphragm (the muscular partition between the chest cavity and the abdomen) where the esophagus passes to enter the stomach. These are known as hiatal hernias. Hernias can occur in other parts of the abdomen usually at sites where there are seams between muscle groups. These are relatively rare and therefore will not be discussed specifically in this article.
Why do human beings develop abdominal wall hernias?
The most common hernias develop at sites where the abdominal wall has natural openings. For example, in the groin, a tube known as the vas deferens which delivers sperm from the testicle to the penis must travel through the abdominal wall (Figure 2). The tube is accompanied by blood vessels and nerves which collectively make up the spermatic cord.
The body must maintain a balance between not being too tight so as to constrict the spermatic cord and being too loose, which would allow other structures from inside the abdomen to slide alongside the cord, forming a hernia. Factors that can upset this balance and lead to a hernia include conditions that increase the pressure in the abdominal cavity, such as obesity, heavy lifting, coughing with chronic lung disease, straining during a bowel movement or urination, chronic lung disease, and fluid in the abdominal cavity(ascites).
The umbilicus (navel or belly button area) is another naturally weak part of the abdominal wall because this is the site of the fetal blood vessels which come from inside the abdomen to connect a developing baby to the mother’s circulation. After a baby is born and the umbilical cord is divided, the muscles beneath the umbilicus usually fuse together to close the opening left by the no longer needed fetal blood vessels. Hernias around the umbilical area occur when this process does not occur properly.
Previous abdominal operation sites are another common place for abdominal wall hernias to develop. Called incisional or ventral hernias, these hernias develop because many operations require that the muscles of the abdominal wall be divided in order for a surgeon to enter the abdominal cavity. The muscles must be sewn back together at the end of the operation. Healing then takes place by the formation of a scar at the re- approximation site. Unfortunately this scar is not as strong as normal human tissue and can separate, resulting in a hole, which is the hernia.
Genetic factors certainly play a role as a family history of frequent hernias is common. Recently, research at the molecular level in hernia patients has uncovered imbalances in collagen, the basic building block of the abdominal wall, and is believed to contribute to hernia disease. There are several types of collagen in the body, two of which are structurally significant with regards to abdominal wall integrity. While type I collagen confers predominantly tensile strength, type III collagen consists of thinner fibers and is regarded as a temporary matrix during tissue remodeling. A decreased ratio of type I: type III collagens can be detected in fascial and skin specimens obtained from patients with hernias.
Developmental phenomenona also plays a role. For example, in the evolution from a quadruped to a biped the unprotected groin is more vulnerable to changes in intraabdominal pressure, predisposing to inguinal herniation (Figure 3).
It is widely believed that a single strenuous activity, such as a heavy lifting episode, is the causative factor of a hernia (i.e., the patient “ruptures” himself). This is questioned by many authorities, however, who feel that physical exertion is less important than commonly believed, as exemplified by the fact that athletes and weightlifters do not seem to have an excessive incidence of hernias. This is a highly controversial area, especially given its ramifications for worker’s compensation issues.
What are the symptoms of a hernia?
The symptoms of a hernia vary widely. Some are completely painless and the patient would not even know he/she had a hernia were it not for a visible bulge or a doctor’s examination during which the asymptomatic hernia was discovered (Figure 4).
On the other end of the spectrum, a patient may present with excruciating pain due to a life threatening condition known as strangulation. Strangulation of a loop of intestine or any other abdominal organ that finds it's way into the hernia sac occurs after the organ becomes incarcerated. Just because an organ enters a hernia sac does not mean that it is incarcerated or strangulated.
Commonly the organ will fall back into the abdomen by itself especially when the patient reclines or it is possible for the doctor or the patient to manipulate the hernia contents manually to force the organ back into the abdomen. This is referred to as a reducible hernia. At some point it may not be possible to reduce the hernia, usually because scar tissue builds up at the neck of the hernia and narrows the opening. The contents are now trapped in the hernia sac. This is known as an incarcerated hernia. An incarcerated loop of intestine is shown in figure 5. One can see a loop of bowel which has found its way through the neck of a hernia into the sac. The neck of the hernia (hole in the abdominal wall) is too small to allow the bowel back into the abdominal cavity.
Even with an incarceration, patients still might remain asymptomatic. However, the stage now becomes set for the dreaded complication of an untreated hernia known as strangulation. Strangulation can mean one of two things: 1) swelling at the neck of the hernia that shuts off the blood supply to the incarcerated contents resulting in gangrene, or 2) the organ, most commonly intestine, becomes blocked, resulting in bowel obstruction. Both conditions require emergency surgery and are associated with a substantial increase in the risk of dying from the surgery, especially in the elderly. Worldwide, hernias are the most common cause of intestinal obstruction and are second only to adhesions in the United States.
Fortunately most patients don't develop strangulation. When a nonstrangulated hernia is symptomatic, the most frequently heard complaint is pain and discomfort in the area of the hernia, which might be aggravated by activities that increase abdominal pressure, such as coughing, sneezing, lifting, straining while having a bowel movement or urinating. Sometimes patients complain of a heavy or burning sensation. If the hernia contains bowel, a gurgling sound can sometimes be heard, which represents normal muscular activity in the bowel. The discomfort can be relieved by manually reducing the hernia back into the abdomen. The patient may have to lie down to accomplish this.
What is an adhesion?
An adhesion is a fibrous band or string like structure between two different organs which are not normally connected or between an organ and the lining of the cavity in which the organ normally resides. They form in response to inflammation and are actually part of the body’s normal response to injury in its attempt to isolate and seal an injured organ.
Anything that can cause inflammation such as infection or trauma, can result in adhesions. In the western world, the most common cause of adhesions is a previous operation because by definition organs are repaired or otherwise manipulated which is associated with inflammation. The vast majority of patients with abdominal adhesions never have problems and don’t even know they have them. Some patients however complain of vague, nonspecific abdominal pain which is felt to be caused by pulling. A more serious complication in the abdomen specifically, is intestinal obstruction caused by a band which constricts the lumen of the intestine or provides a fulcrum for the bowel to twist around.
Symptoms tend to be worse with larger hernias but this correlation is not strong because on occasion even hernias that are not visible, but only detectable by a doctor’s examination, are very painful. In addition to pain at the site of the hernia, patients may experience pain that radiates away from the hernia. For example, a patient with a groin hernia might complain of testicular or leg pain. This is called referred pain and is usually due to the hernia pressing on a sensory nerve.
What is a Sensory Nerve?
The nervous system of the human body has two main components. The central nervous system(CNS) which includes the brain and the spinal cord and the peripheral nervous system which includes all nerves throughout the body leading to and from the CNS. There are two main types of peripheral nerves: 1) Motor which are responsible for making muscle groups move and 2) Sensory which deliver various sensations such as pain or temperature to the CNS.
Groin (Inguinal) Hernias
Types of groin Hernias
Hernias of the groin are divided into three types (Figure 1):
An indirect hernia is the most common type of groin hernia and is considered congenital because it is the result of incomplete closure of the passage way from the abdomen to the scrotum when the testicles normally descend into the scrotum at about 28 weeks in gestation. As might be expected, these are frequently detected in newborns. However, this hernia can also develop any time in life because the passageway may be so small that contents from inside the abdomen cannot get into it. Over time, the space gradually enlarges and a hernia develops. The hernia passageway traverses the inguinal canal along with the spermatic cord in males, or the round ligament in females. It is called indirect because the inguinal canal takes an oblique course from inside the abdomen towards the scrotum (Figure 1,E).
In the past, a strenuous event such as heavy lifting was felt to be an important cause of the development of these hernias, i.e., the patient would ”rupture” himself: the heavy lifting event would force something from inside the abdomen into the passageway like a wedge. As noted above, this theory is now questioned by many authorities.
Direct hernias are about one half as common as are indirect, and are the result of weakened muscular tissue in the groin area rather than a congenital abnormality (Figure 1,D ). They do not follow the oblique pathway of the inguinal canal but rather travel directly through the abdominal wall, hence the name direct.
Femoral hernias follow the canal that contains the main vessels that supply blood to the leg. They are more dangerous than direct or indirect hernias because the opening of the canal has rigid borders, making it more likely to trap contents in the hernia, resulting in strangulation.
Facts about groin hernias
Inguinal hernias are more common on the right than on the left and occur seven times more frequently in males than in females. Indirect inguinal hernias are twice as common as direct hernias. Femoral hernias are much less common than either, accounting for fewer than 10% of all groin hernias; however, 40% of femoral hernias present as emergencies, with incarceration or strangulation, and mortality is higher for emergency repair than for elective repair. Therefore, it is important to know who is at risk for a femoral hernia. Femoral hernias are more common in older patients and in those who have previously undergone inguinal hernia repair (called a recurrent hernia). Females are at higher risk for a femoral hernia than males, by a factor of 4 to 1.
Treatment of Groin Hernias
Surgery is the only way to repair a groin hernia. However, there are devices called trusses (hernia belts) which can be strapped on to the waist area, which will place pressure on the bulge preventing it from “coming out” ( Figure 6). In some patients they are very effective in controlling symptoms. Many patients complain they are cumbersome to put on and are difficult to keep clean and odor free.
There are three types of hernia surgeries which might be recommended to a patient:
The first type is a tissue repair. In this operation, a three to five inch incision is made in the groin area over the hernia and the hernia sac is identified and either removed or placed back in the abdomen. The patient’s own tissues are then sewn together to close the hole in the abdominal wall.
There are many variations in the technique used to close the hole, which can be confusing to remember, as they usually bear the names of the surgeon that described the variation (for example, Marcy, Bassini, Moloney Darn, Shouldice, McVay-Cooper’s Ligament and many others). The choice of which tissue repair your surgeon might recommend to you would depend almost exclusively on his or her training and expertise. The advantage of this type of repair is that a foreign body prosthesis (See below) is not used, only the patient’s own tissue. These operations were by far the most commonly performed for groin hernias until the last part of the 20th Century, when prosthetic repairs became so popular.
Surgeons stuck with the tissue repairs because they feared complications with the foreign body prosthesis, such as foreign body rejection, infection, erosion into surrounding structures, cost and others. However by the late 1980's enough data had accumulated that made it clear that these complications were not being seen. At the same time, data was also showing that the long term failure rate (i.e., recurrence of the hernia) was much higher than individual surgeons would have assumed from there own practices, probably in the range of 10-15%. These types of repairs are rarely used in general practice now, except in children and adolescents and in patients who for personal reasons prefer not to have a prosthesis used.
The exception to this is in highly specialized hernia clinics where no other operation is performed. The surgeons develop so much expertise that their results can rival the newer operations which are discussed below. The best example of this is the Shouldice Clinic in Toronto, Canada (http://www.shouldice.com/). The surgeons at the Shouldice clinic have developed a unique tissue repair which uses multiple layers to close the hernia defect and has a failure rate of less than 1%. The results are almost never this good when surgeons outside of the clinic attempt to replicate the operation.
[What is a Foreign Body Prosthesis? In surgical procedures, a prosthesis is defined as an artificial device used to replace a missing or defective body part. It is sometimes possible to construct a prosthesis from the patient's own tissue. For example, in the past for hernia surgery, some of the lining or fascia of the muscles of the leg has been harvested to replace defective tissue. However obtaining this tissue subjects the patient to a second surgical incision in the leg which is painful and unsightly. For this reason almost all prosthetic material used for hernia surgery today are made from substances not natural to the human body; thus the term foreign body prosthesis.
[Prosthetic material used for hernia surgery can be made from plastic, titanium, stainless steel, Teflon and other substances. For hernia surgery, these materials are most commonly manufactured into a mesh which looks like a screen with square spaces between strands of fabric. Mesh works well for hernia repairs because dense scar tissue can grow into the empty spaces resulting in a very strong patch for the hole which is the hernia]
The next two types of groin hernia repairs have in common the use of some type of prosthesis, usually a mesh material. The so-called tension-free repair (TFR) begins with an incision similar to that used for the tissue repairs and the hernia sac is again either removed or placed back in the abdomen. Instead of closing the hole with sutures, a piece of material, usually a plastic mesh, approximately 6 by 4 inches, is used to bridge the hole. Since the hole is not actually closed, there are no sutures under tension. Thus the name tension-free repair. The mesh is attached to specific land marks at the periphery of the groin area so that in effect not only is the hernia corrected but all potential sites of another hernia are covered.
This is felt to account for the operation’s superiority over the tissue repairs, as the recurrence rate (rate at which the hernia comes back over the lifetime of the patient) is 1% or less with experienced surgeons. The most common operation performed in the Western world is the tension-free hernia repair known as the Lichtenstein technique (Figure 8). In this operation polypropylene mesh is used to cover the entire inguinal floor.
The mesh is slit on its lateral side, creating tails that can be positioned around the spermatic cord as it enters the inguinal canal. The tails are then sewn back together on the lateral side of the cord, greatly strengthening this naturally weakened area where the spermatic cord traverses the abdominal wall. As with the tissue repairs, there are several variations of this procedure. For example, the second most popular TFR, after the Lichtenstein, is the plug and patch technique. In this procedure, a piece of the plastic mesh is rolled up to form a plug, which is then placed in the hernia hole (Figure 9). A second piece of flat mesh is then placed on top (thus the name plug & patch).
As is always the case in hernia surgery, the most important determinate for which type of tension-free operation is chosen is the training and expertise of the surgeon for any given variation.
The third type of inguinal hernia repair is laparoscopic. Laparoscopy is the examination of the contents of the abdominal cavity with a telescope passed through the abdominal wall. The development of small, sterilized video cameras that are attached to the laparoscope, allowing the image to be displayed on a video monitor, revolutionized general surgery. With this advance, complex operations that required an operative team could be performed with the entire team able to see the same image, as apposed to a single operator looking through the eyepiece of the scope.
In the late 1980s and early 1990s, many routine surgical procedures formerly requiring a large, painful, open incision, such as appendectomy, cholecystectomy, hysterectomy, splenectomy and many others were adapted to the laparoscopic method. The advantages of this so-called minimally invasive surgery are obvious, and include less pain, shorter hospital stay, and earlier return to normal activities when compared with their traditional open counterparts.
Not surprisingly, a laparoscopic inguinal hernia repair was also developed. In this procedure the abdomen is first inflated with carbon dioxide gas and then three or four small incisions (1/2 inch or less) are made; one in the umbilicus and the other two on either side of the umbilicus or between the umbilicus and the pubic bone, and special tubes called trocar sleeves are inserted.
These trocars, as they are commonly abbreviated, have valves which allow the surgeon to pass the laparoscope as well as surgical instruments in and out of the abdomen without the loss of the carbon dioxide gas. The inguinal hernia (hole in the abdominal wall) is then identified from the inside of the abdomen (Figure 11) and the sac is pulled out of the hole back into the abdomen (“reduced” is the medical term).
A mesh prosthesis, as was described for the TFR operation, above is now brought into the abdomen and used to cover the hole, widely overlapping not only this hernia but all areas of future herniation in the groin.
The theoretical advantage of the laparoscopic inguinal hernia repair is that it has the benefits of minimally invasive surgery, such as smaller incisions (and therefore improved cosmesis), less pain, and earlier return to normal activities. It is also stronger, because placing the mesh on the abdominal side of the groin, beneath the muscles, provides mechanical advantage. When the patient strains the mesh is actually “seated” into the muscle rather then tending to be lifted off, as may occur when the mesh is on the outside of the abdomen in the TFR technique. The principle is best illustrated by imagining your car tire with a leak that needs to be patched. Would you rather have the patch on the inside of the tire, where air would keep it in place or on the out side where the air might be a factor in dislodging it?
In fact though, the benefits of minimally invasive surgery for inguinal hernia repair are not as obvious as for other procedures and the operation has not gained wide adoption by United States surgeons. Less than 20% of inguinal hernia repairs are performed with this method.
Just why is this? There are several reasons:
1) Widespread adoption of the open TFR operation by American surgeons took place through the 1990s at the same time that the laparoscopic operation was introduced. The result was that the mechanical advantage gained by placing the mesh prosthesis on the abdominal side of the muscles was really not of much significance because the failure rate was so low with either approach.
2) The operation must be performed under general anesthesia, which means the patient must be put to sleep and placed on a ventilator during the procedure. On the other hand, the TFR procedure can be performed under local anesthesia with or without the addition of twilight sleep sedatives. Most agree the latter is safer.
[ What is local anesthesia? a drug such as novocaine is injected in the area of an operation. Such a drug has the ability to chemically interact with nerves to numb them temporarily so the patient cannot perceive pain.]
3) It is much more expensive. A laparoscopic operation requires high tech equipment to provide intense light and superior camera optics to be able to work inside the abdominal cavity. On the other hand, the TFR operation only calls for basic surgical instruments.
4) There is a very slight risk for serious and even fatal complications which simply do not exist for the TFR operation. This is because the surgeon is working in the abdomen. Accidental damage to a nearby abdominal organ can occur, and if not recognized immediately by the surgeon, can have disastrous consequences.
5) The laparoscopic operation is technically complex and is more difficult for the surgeon than is conventional open hernia surgery. Extensive training and experience is necessary for surgeons to achieve consistently good results. This point was clearly made in a highly controlled, well-financed, multi-center landmark study conducted by the Veterans Affairs Cooperative Studies Program.
This study compared an open mesh technique (the Lichtenstein) with a laparoscopic mesh for repair of an inguinal hernia. On the plus side for the laparoscopic operation, patients did experience less pain from the operation and returned to everyday activities more quickly. However, recurrence of the hernia (the hernia coming back) was significantly more common after the laparoscopic procedure than after TFR and there was one death from an unrecognized bowel injury in the laparoscopic group.
The surgeons performing both operations in the VA study were experienced, but for the most part without a specialty interest in hernia surgery. It is postulated that the increased technical complexity of the laparoscopic operation, when compared with TFR, is responsible for the difference and therefore equivalent results may not be the case outside of centers with a dedicated interest. This study, and others with similar results, have lead major organizations that publish guidelines for patients, such as the United Kingdom’s highly respected National Institute for Health and Clinical Excellence (NICE http://www.nice.org.uk/) to suggest that the laparoscopic operation should only be performed in specialty units.
In recent years, several hybrid operations have been described which are open but borrow from the laparoscopic principle of placing the mesh behind the muscle. In the Kugel procedure a relatively small incision is made through the full thickness of the abdominal wall and a specially designed polypropylene prosthesis with a flexible ring (that allows the device to be deformed) is placed behind the muscles through the small incision. Once behind the muscle, the ring springs back to its original shape and covers all the areas of potential herniation. Another example is the Prolene Hernia System. In this procedure a bilayer prosthesis with two sheets of mesh connected by a cylinder (Fiure 13) is used to place a piece of mesh both in front of and behind the muscles, combining features of both the TFR and the laparoscopic methods. These variations work well only when the surgeon has been specifically trained and proctored by a more experienced surgeon.
The bottom line is, where there is more than one type of surgical option, the most important determinant of success is the experience of the surgeon. The laparoscopic approach has the advantages of less post operative pain, earlier return to normal activity and improved cosmesis, but also has a higher failure rate and the possibility of severe complications. If your surgeon is not highly experienced in the more complex laparoscopic operation, you are better off choosing a conventional open operation. If in doubt, one can inquire about surgeons to organizations such as the American Hernia Society (http://americanherniasociety.org/), the American College of Surgeons (http://www.facs.org/) the Society of American Gastrointestinal and Endoscopic Surgeons (http://www.sages.org/), the Society for Surgery of the Alimentary Tract (http://www.ssat.com) or the Creighton University Center for Abdominal Wall Reconstruction.
Maybe No Treatment at All!
In the past, surgeons were taught that all inguinal hernias should be repaired when discovered to prevent the feared complication of strangulation, (see definition above) despite the fact that about half the time inguinal hernias are asymptomatic or only minimally symptomatic. This was especially true at a time in the past when immediate medical care was not available to a substantial number of people. Strangulation remains a serious problem even today, but with the widespread availability of urgent care almost everywhere in the developed world, the concern has lessened. Indeed, today, unless there is a delay in treatment, morbidity and mortality rates are only slightly higher than for a non-strangulated hernia.
On the other hand, groin hernia operations, while generally safe and effective, are considered relatively painful as operations go, and carry a long-term risk of hernia recurrence or chronic pain from scar tissue resulting from the surgery (see complications below). This provided the impetus to explore a strategy of observation (watchful waiting or “WW”) for patients with very few symptoms from their inguinal hernia.
In another landmark study funded by the United States Agency for Healthcare Research and Quality (http://www.ahrq.gov/) and conducted by the American College of Surgeons (http://www.facs.org/) in five centers throughout the United States and Canada, 720 men with asymptomatic or minimally symptomatic inguinal hernias were randomly assigned to a strategy of watchful waiting or surgical repair between January 1, 1999, through December 31, 2004 (364 watchful waiting, 356 surgical repair). At the end of the study there was almost no difference between the two groups in terms of pain, physical function, and other outcomes. About one third of the patients assigned to watchful waiting had crossed over to hernia repair by the end of the study because of increasing symptoms but the delay in treatment did not seem to have adverse consequences. Post-operative hernia-related complications were the same in patients who received repair immediately and in the watchful-waiting patients who crossed over.
But what about the serious strangulation risk? The answer is that only two patients required emergency operations for a strangulated hernia, for a strangulation rate of 1.8 per 1000 patient-years. For a patient considering WW, this translates into a lifetime risk of about one fifth of 1% per year.
Complications of Groin Hernia Repairs
In the past, surgeons were concerned almost exclusively about the rate at which hernias recurred (the recurrence rate) when considering complications. However now that the recurrence rate has become so low with the newer operative approaches, chronic post herniorrhaphy (herniorrhaphy is the medical term for hernia repair) groin pain has emerged as perhaps the most significant issue facing hernia surgeons and is currently the subject of intense research. Chronic groin and leg pain occurs in a small percentage of patients after inguinal hernia surgery and can be very severe. The exact incidence is unknown but a recent comprehensive review estimated that it occurs in about 1 in 10 inguinal hernia repairs.  In that review, it was reported to be mild to moderate in the majority, not interfering greatly with activities of daily living. But in about 10% of the group who had pain (1% of all patients undergoing an inguinal hernia operation) it was severe, sometimes incapacitating. The complication is equally frustrating to both the patient and the surgeon because the cause is not known.
The incidence seems to be the same no matter what type of inguinal hernia operation was performed (e.g., tissue vs. TFR; or open vs. laparoscopic). The pain is divided into two types: The first is neuropathic due to damage or entrapment by scar tissue, mesh, staples or sutures of one or more of the key sensory nerves (see definition above) in the groin area or leg. In the past, treatment of patients with this complication has concentrated almost exclusively on the neuropathic cause but this has been questioned by surgeons because a second operation to remove the nerve (neurectomy) often doesn’t solve the problem.
The second type of pain is called nociceptive and probably represents the most common variety. It is further subdivided into: 1) somatic which is the most common and is related to ligament or muscle injury, scar tissue, inflammation of the pubic bone, or reaction to prosthetic material, and 2) visceral occurring at the time of specific visceral functions such as urination or ejaculation.
Diagnostic evaluation of these patients is difficult because they usually have a completely normal physical examination and the complaint is purely subjective. Secondary gain (see definition below) associated with worker’s compensation issues often complicate the situation even further. Perhaps the single most important determination is to decide if the pain is the same that brought the hernia to the attention of the physician in the first place. In other words, was the pain assumed to have been caused by the hernia before surgery really caused by something else?
Computed tomography (CT), ultrasonography, herniography, laparoscopy, and magnetic resonance imaging (MRI) all have their place in the evaluation. The goal is to rule out hidden causes not readily apparent by physical examination. MRI has emerged as the most beneficial imaging tehnique because of its ability to differentiate between muscle tear, inflammation of the pubic bone, bursitis, and stress fracture.
[Secondary gain is defined as a financial or interpersonal advantage gained indirectly from organic illness, such as continued reimbursement for salary while not working or an increase in attention from others.]
At ttp://wwCreighton University’s Center for Abdominal Wall Reconstruction, a five-step protocol is followed for the treatment of patients with post-operative pain.
The first adopts conservative measures, including anti-inflammatory medication and ice or heat. In step two we go on to the imaging studies noted above. If normal, step three is physical therapy, using very specific stretching exercises; many times very good results are seen with this modality, especially when the physical therapist has a specific interest in this problem. Step four is referral to a pain management clinic, where various local therapies are tried, such as nerve blocks, cryotherapy, transcutaneous electrical nerve stimulation (TENS), and even acupuncture.
The final, and fifth step is surgery. A combined laparoscopic and open groin operation is usually required so that all adhesions and scar tissue can be divided, and as much foreign material (i.e., mesh, staples, sutures) as possible can be removed. A so-called Triple Neurectomy is also performed, which means removal of the three main sensory nerves in the area (Ilioinguinal, Iliohypogastric, and Genitofemoral). The reason such an extensive surgery is recommended is because of the inability to determine the exact cause and therefore all potential etiologies of the pain must be addressed. The operation has a high complication rate, with damage to the spermatic cord and testicle being the most feared. Fortunately, we rarely get to step five because one or more of our other measures work.
Other complications include those related to the spermatic cord and testicle. Ischemic orchitis is a condition in which the testicle becomes inflamed and swollen within one to five days after surgery. The presenting symptoms include a low-grade fever with painful enlargement of the testicle. It is treated with scrotal support and anti-inflammatory agents. Ischemic orchitis usually resolves without long term consequences but occasionally may progress to testicular atrophy, which means the testicle shrivels up and will no longer work. Operative damage to the cord can result in blockage of the Vas Deferens, making it impossible for sperm to pass. Cord and testicular complications are of most concern in patients who have hernias repaired on both the left and right side because infertility would be the inevitable result if a problem developed on both sides.
As with any operation, wound infection is possible, as is bleeding (a hematoma), which can occur in either the groin or the scrotum. Another complication is a fluid collection (called a seroma when in the groin, and a hydrocele when in the scrotum). Fortunately, these are not common and usually require minimal treatment to resolve. Prosthetic complications (mesh) occur at a much smaller rate then had been anticipated when they were first introduced in the 1950s. Perhaps the most significant is mesh migration of polypropylene plugs into nearby organs, such as the bladder, which has been reported but is rare. Local erosion of flat mesh into cord structures has also been reported but is even rarer. Rejection due to allergic reactions is almost never seen. Bladder or bowel injuries are almost unheard of with the conventional anterior herniorrhaphy but are possible with the laparoscopic approach.
The term “sports hernia” is confusing, even to physicians, because by definition the patient doesn't actually have a hernia. It is discussed under the general topic of hernia because they occur in the groin, and when operation is required the procedure is very similar to a standard hernia repair. But the cause of the hernia is not a hole with a neck and a sac, but rather just weakened or stretched tendons or muscles in the groin area, which leads to pain that interferes with function. The diagnosis is essentially one of exclusion when a patient presents with groin pain and no obvious cause by physical examination or x-ray studies. There is considerable interest in sports hernias because they commonly occur in high profile athletes whose occupations are significantly impacted by the condition.
Umbilical Hernias (Navel Hernias)
Umbilical hernias occur through or just to the side of the belly button (Figure 1, C). The latter are referred to as paraumbilical hernias. Umbilical hernias are treated according to the age of the patient. The majority of hernias occurring in children younger than 2 years will heal spontaneously; therefore, watchful waiting is the rule, and only symptomatic hernias are repaired. In children older than 2 years and in adults, surgical correction is required, with the type of repair employed depending on the size of the hernia. If the defect is small (< 1 inch), a direct suture tissue repair may be performed. For larger umbilical and paraumbilical hernias, particularly those in adults, a mesh repair is preferred. Patients with very large hernias, previous failed repairs, or those who are very obese, are particularly suited for laparoscopy because a large prosthesis can be placed on the organ side of the hole in the abdominal wall, overlapping the hole widely.
Incisional hernias, by definition, occur through previous abdominal incisions (Figure1, B). The term “ventral hernia” is often used interchangeably with incisional hernia but this is really not accurate because any hernia in the front part of the abdomen is ventral, e.g., umbilical or epigastric. The basis of the hernia is separation at the site where the abdominal muscles were reapproximated (re-attached) after an abdominal operation. There may be a single hole, or a so-called Swiss cheese hernia, where there are multiple holes. There are many causes, including impaired wound healing on the part of the patient due to chemical and molecular imbalances, infection at the time of the original operation, poor surgical technique in closing the original incision, genetic factors, cigarette smoking, excessive coughing, and obesity just to name a few.
Incisional hernias can be unsightly, painful, alter a patient’s lifestyle and employment opportunities, and carry a risk of incarceration and/ or strangulation. (see definition above) In some patients there are minimal or no symptoms and the hernia is easily pushed back into the abdomen (reduced). Watchful waiting is an acceptable strategy in this group. Hernia belts are worn by some patients (Figure 14) but they probably do little to prevent enlargement or complications, although they do provide support.
The only way to repair an incisional hernia is surgery. It will not heal on its own. In contradistinction to groin hernias, where operative repair results in a very low hernia recurrence rate, incisional hernia repair has a very high failure rate. For this reason incisional hernia repair has evolved significantly in the last 10 years from one which was formerly dominated by simple one or two layer suture techniques to today where there are so many approaches that it is even difficult for surgeons, let alone primary care physicians or patients, to determine what is best. Simple suturing for conventional open surgery has been replaced by the use of prosthetic material in nearly all adult patients.
Laparoscopy is now commonly recommended for incisional hernias but has specific risks which must be assessed in individual patients to make sure the operation is safe. Many new types of prosthesis, both plastic and “biologic” (designed to be remodeled into what looks histologically like normal tissue rather than the scar barrier produced by the plastic meshes), have been designed for specific clinical situations. Even the decision as to where to place a prosthesis, i.e., behind the muscle (underlay), between the muscles (inlay), or on top of the muscle (overlay), can be problematic. More than ever before, it is important that patients seek out a knowledgeable, experienced surgeon capable of explaining these various choices as it would be virtually impossible for a lay person to do enough research to sort all this out on his or her own.
This hernia protrudes though the narrow strip of fascia which connects the two rectus muscles in the middle of the abdomen (the linea alba ). They can occur anywhere from the navel to the breast bone. In the majority of these patients, the fibers of the linea alba in the area of the hernia are defective, leading to the hernia (Figure 1, A). Twenty percent of these patients experience multiple hernias. Most are less than one half inch in diameter and contain only fat from the space between the lining and the muscles of the abdomen, known as the preperitoneal space. When symptomatic, patients complain of a painful nodule in the upper midline which can be quite uncomfortable because the necks of these hernias are small and can tightly constrict the preperitoneal fat. At this stage there is no sac and therefore no risk of strangulation of abdominal contents. Repair by slightly widening the neck and pushing the fat back into the preperitoneal space (i.e., reducing the hernia), and simple closure of the defect cures the symptoms. These hernias are prone to recur, with rates as high as 10%. Some surgeons therefore prefer to place a postage stamp-sized piece of prosthetic material in the preperitoneal space to reinforce the repair. Left untreated, an epigastric hernia can become large enough to develop a peritoneal sac into which intraabdominal contents can protrude. The hernia then must be treated as if it were an incisional hernia.
Diaphragmatic hernias can be congenital or acquired. (see definition below) Congenital diaphragmatic hernias are seen in 1 out of 2,200 to 5, 000 live births. Most affect the left side. They are caused by the improper joining of the muscles of the diaphragm during fetal development. Abdominal organs such as the stomach, colon, small intestine, spleen, part of the liver, and kidney migrate into the chest cavity. As a result, the lung tissue on the affected side cannot develop properly. A Bochdalek hernia involves the left side while on the right the hernia is called a Morgagni hernia. Babies born with these hernias have severe breathing problems related to their poor lung development. The breathing problem must be stabilized before surgery can be performed to place the organs back into the abdomen and repair the hole in the diaphragm.
[An acquired condition is one that is not congenital or inherited but develops with age]
A much more common diaphragmatic hernia is an acquired one which occurs through the natural opening in the diaphragm known as the esophageal hiatus. As the name implies, this is the opening that allows the esophagus or food tube to pass from the mouth to the stomach. The most common type is the sliding hiatal hernia. Discussing this condition is confusing because this is not the typical type of hernia that has been described throughout this article.
There is no neck or sac and there is no risk of strangulation. Rather the junction where the esophagus joins the stomach, which normally resides in the abdomen, migrates or “slides” through the esophageal hiatus into the chest (See Figure 15). You might ask, if there is no risk of strangulation, why is it important? In fact, it usually isn’t important, as a substantial percentage of the population have sliding hiatal hernias and don’t even know it. Sliding hiatal hernias are frequently seen on x-rays done for other reasons in patients who have no complaints related to the esophagus.
The real importance of a sliding hiatal hernia is its association with gastroesophageal reflux disease or GERD, a condition in which the lower esophageal sphincter does not function properly allowing stomach contents to reflux into the esophagus, causing heartburn, acid indigestion, and possible injury to the esophageal lining. GERD is consistently present in patients with large sliding hiatal hernias because the valve between the esophagus and the stomach, which is responsible for keeping the contents in the stomach (gastric contents) from refluxing back into the esophagus, is rendered ineffective. Thus, the name gastroesophageal reflux disease, the sine qua non of which is heartburn – not typical hernia symptoms. Adding to the confusion is the propensity for patients (and their doctors!) to use the terms GERD and hiatal hernia interchangeably, which is not correct.
In fact, only about 50% of patients with GERD even have a hiatal hernia and as noted previously, the vast majority of people with sliding hiatal hernias don’t have GERD or any other symptoms for that matter. For more information on GERD please visit Creighton University’s web site which deals with the subject.
True hernias with a neck and a sac can also develop along side the esophagus with the sac protruding into the chest (Figure 16). These are called paraesophageal hernias. They are much less common than sliding hiatal hernias ( 85% sliding/15% paraesophageal). These hernias can become quite large, with the entire stomach and other organs such as the colon or spleen, protruding into the sac.
Figure 16 A Paraesophageal Hernia with the Stomach Protruding into the Chest
When this big, patients often have difficulty eating because the stomach cannot function well when it is so displaced. They might also have difficulty breathing because the organs take up space the lungs need to expand properly. The treatment is to pull the organs back into the abdomen and close the hole in the diaphragm, with or without a prosthesis. This operation can usually be done laparoscopically but will occasionally require an open procedure. The surgery is tricky because care must be taken to close the hole tightly enough to prevent a new hernia from forming, yet loosely enough so as not to interfere with the patient’s ability to swallow.
Miscellaneous Abdominal Wall Hernias
In addition to the more common abdominal wall hernias discussed above, there are numerous other hernias which occur very rarely. It is not practical to describe all of these in this Knol but in the next few paragraphs some of them will be touched upon. A Diastasis Recti, while not truly a hernia, looks like one to the patient and therefore is legitimately part of a discussion on abdominal wall hernias.
In this condition, the two rectus abdominis muscles are separated quite widely, and the linea alba is stretched, and protrudes like a fin between the naval and the breast bone, especially when the patient performs a sit-up. This is not truly a hernia but a normal anatomical variant which worsens with age. However, many patients find it unsightly and request treatment, despite the fact that there is no inherent risk of complications due to the anatomic variation. Therefore most insurance companies consider the operation cosmetic, and will not approve it for payment.
The following hernias have in common that they are treated like incisional hernias when surgery is called for. Parastomal hernias occur at sites where bowel has been brought through the abdominal wall to form a colostomy or ileostomy stoma (see the American Cancer Society Web site, (http://www.cancer.org/treatment/treatmentsandsideeffects/physicalsideeffects/ostomies/colostomyguide/index). They occur frequently with stomas but rarely cause symptoms, and are never repaired unless there are overwhelming indications such as severe pain or inability to keep the stoma appliance in place. Laparoscopic repair is becoming increasingly popular.
Spigelian hernias occur at a seam between muscles of the abdominal wall at the lateral border of the rectus muscle. Supravesical hernias (vesical = urinary bladder) develop anterior to the urinary bladder, as a consequence of failure of the integrity of the muscles in this area. Lumbar hernias, as the name implies, are hernias that protrude through weaknesses in the back of the abdomen. The superior lumbar hernia of Grynfelt and the inferior lumbar hernia of Petit occur through specific anatomical areas where various bones and muscles in the back abut each other. Lumbar hernias can also develop as a result of trauma (mostly surgical e.g., kidney surgery) or infection.
1. Owings MF, Kozak LJ. Ambulatory and inpatient procedures in the united states, 1996. Vital Health Stat 13. 1998;(139):1-119.
2. Jansen PL, Mertens Pr P, Klinge U, Schumpelick V. The biology of hernia formation. Surgery. 2004;136:1-4.
3. McIntosh A, Hutchinson A, Roberts A, Withers H. Evidence-based management of groin hernia in primary care—a systematic review. Fam Pract. 2000;17:442-447.
4. Neumayer L, Giobbie-Hurder A, Jonasson O, et al. Open mesh versus laparoscopic mesh repair of inguinal hernia. N Engl J Med. 2004;350:1819-1827.
5. Fitzgibbons RJ,Jr, Giobbie-Hurder A, Gibbs JO, et al. Watchful waiting vs repair of inguinal hernia in minimally symptomatic men: A randomized clinical trial. JAMA. 2006;295:285-292.
6. Nienhuijs S, Staal E, Strobbe L, Rosman C, Groenewoud H, Bleichrodt R. Chronic pain after mesh repair of inguinal hernia: A systematic review. Am J Surg. 2007;194:394-400.
7. Anderson K, Strickland SM, Warren R. Hip and groin injuries in athletes. Am J Sports Med. 2001;29:521-533.
This page is provided by Ground Up Strength for information purposes only and should not take the place of professional medical advice. Although we have done our utmost to provide accurate and safe information, we are not medical professionals and the information on this page should not be taken as professional medical advice, or any other kind of medical advice.