US Pharm. 2017(42):HS-10-HS-13.
Abdominal hernias are protrusions of the bowel through a weakened part of the abdominal muscle wall.1 The hernia may be classified as external when it extends beyond the abdominal cavity and is visible on the body surface; it is classified as internal when the protrusion is limited to the peritoneal pockets.2 Depending upon size of the protrusion, the hernia may be complete or incomplete, and based upon its formation it may be classified as a congenital or acquired hernia.2 Hernias may also be divided according to their site of occurrence, such as abdominal, diaphragmatic, perineal, or lumbar hernia.3 This article will focus on three types of abdominal hernias: inguinal, umbilical, and femoral.
Inguinal Hernias: The most common type of hernia in both sexes, inguinal hernias constitute 75% of hernias.2,4 It has been shown that of the one million abdominal wall hernia repairs performed each year in the United States, inguinal hernia repairs constitute nearly 770,000 of these cases.5 They may occur in people of any age, ranging from infants (especially in premature babies) to the elderly. Inguinal hernias should be repaired early to reduce the risk of strangulation and to minimize stretching of the abdominal wall musculature, thereby reducing the rate of recurrence. Strangulation is said to occur if the blood flow to the hernia is cut off due to incarceration—that is, when the hernia becomes trapped in the abdominal wall.4
Umbilical Hernias: Umbilical hernias can develop at any age in the natural opening of the umbilicus. They account for about 14% of hernias and are the third most common disorder in children after hydroceles and inguinal hernias.2,5 Most umbilical hernias in children are asymptomatic, even though they may seem unsightly. Umbilical hernias that occur in infants disappear by the age of 2 years in 90% of cases. Furthermore, complications such as strangulation of omentum or intestine and evisceration occur in only about 4% of cases. Surgical repair of such hernias is indicated only in patients who have complaints or complications, or if the hernia persists beyond the age of 2 years.2
In adults, however, umbilical hernias are indirect herniations through the umbilical canal that have a high tendency to incarcerate and strangulate and do not resolve spontaneously. Most of these patients are women or overweight adults.1,2 Surgery is recommended in these patients since the risk of incarceration is as high as 30%.2
Femoral Hernias: Femoral hernias make up only 3% to 5% of hernias and involve the protrusion of the peritoneum into the potential space of the femoral canal.4 Up to 75% of femoral hernia cases occur in females; inguinal hernias are predominantly seen in males (80% to 90% in males and 10% in females).2 Furthermore, femoral hernias are more common in multiparous women and are rare in children.4
Since the femoral canal is small, femoral hernias strangulate readily; although most patients present with signs and symptoms of small-bowel obstruction, repair should be undertaken at the earliest opportunity even in asymptomatic patients.4 Treatment of femoral hernia involves operative therapy, preferably with the use of a mesh.2
PATHOGENESIS
Hernias can result from a number of factors; based upon their formation they can be classified as:
Congenital Hernias: Congenital hernias are preformed openings, and arise due to incomplete closure of the abdominal wall.
Acquired Hernias: Acquired hernias develop over time, especially in locations where larger blood vessels lie or where previous incisions were made. These are a result of increased dehiscence of fascial structure with accompanying loss of abdominal-wall strength.2
Various factors have been identified as contributing to the pathogenesis of hernias. These include increased intra-abdominal pressure, which may occur in pregnancy, or from intra-abdominal tumors, chronic obstructive lung disease, ascites, chronic intestinal obstruction, and adiposity; or pathological changes in connective tissue of the abdominal wall.2 While the weakening usually develops over time, in some cases the hernia may suddenly arise due to a bout of coughing, lifting heavy weights, doing heavy manual work, or straining to pass stool.1
DIAGNOSIS
While some hernias may be asymptomatic, others may only be diagnosed during the presentation of a complication associated with the hernia.
External hernias typically present with a bulge that can be detected during a physical examination. The bulge is noted while the patient is standing and straining down (called the Valsalva maneuver). Imaging is rarely needed to diagnose a hernia, but may be particularly useful in internal hernias or other situations such as recurrent hernia, uncertain diagnosis, surgical complications, or the presence of chronic pain. In such cases radiography, ultrasonography, computed tomography, or magnetic resonance imaging may be employed to detect the hernia. Laboratory studies may be required to rule out a differential diagnosis and may include stain or culture of nodal tissue, a complete blood count, electrolytes, blood urea nitrogen, creatinine, and lactate levels, as well as a urinalysis.5
TREATMENT
Hernias are normally corrected surgically; in some cases this is an urgent requirement, particularly when there is a risk of strangulation.1 However, there are times when a mechanical means of support to hold the hernia in, known as a truss, may be the preferred option. Trusses are particularly useful as a long-term measure in patients who are too old or ill to withstand surgery, or as a temporary measure in the interval between diagnosis and surgical correction.1
Reducing a Hernia
Before a truss can be fitted, the healthcare practitioner must ensure that the hernia is reducible, i.e., the protruding abdominal mass can be returned through the weakened muscle into the abdominal cavity. It is useful to note that reducing a hernia is not the role of the pharmacist. In a simple scenario, reducton involves the manipulation of the hernia in an upward direction with one hand and the backward direction with the other hand to return the mass to the abdominal cavity. If the hernia is not reducible, a truss must not be fitted or supplied because this will increase the risk of strangulation. If reduction is performed in the emergency department, a surgeon should be available in case the hernia cannot be reduced, there is a risk of strangulation, or there are comorbid risks for sedation.6-8
Trusses
Trusses can in most cases be measured, supplied, and fitted in an outpatient setting in hospital or community pharmacies.
A truss consists of a pad that is placed over the reduced hernia and a belt that keeps the pad in place. The belt may be made of a rigid spring or flexible elastic and is designed to assist the pad in exerting an upward and backward force.1
Truss pads come in a variety of shapes and sizes, depending upon the type of hernia they are being used for. For example, the pad of a truss for an inguinal hernia is an oval shape with the narrower end placed at the top of the inguinal canal. Pads for femoral hernias are a mix of inguinal and scrotal pads, and may require extra support to keep them in place. Umbilical hernia pads for use in adults have a padded plate with a central raised cone that sits over the umbilicus when correctly fitted. In children, a porous natural rubber belt is sufficient and a central cone is not required. A web belt may be used in children who are sensitive to rubber.
The pad may be supported by either an elastic band or a spring, with the latter providing more support to the hernia pad than the elastic belt. An elastic-band truss requires an understrap to keep it in place, whereas a spring truss does not usually require an understrap. However, elastic bands tend to be more popular because they are less obtrusive below clothing and feel more comfortable. Elastic bands commonly require replacement in less than 12 months, whereas a spring truss can last for up to 2 to 3 years.1
When measuring for a truss, it is important that the measuring tape is positioned correctly. It should be placed around the body just above the buttocks at the rear and between the top edge of the hip bones (iliac crests) and the hip joints (great trochanters) at each side. The measurement for the truss is taken where the tape crosses at the pubis. For a perfect fit, minor modifications to some measurements may be required. For example, overweight patients may require a tighter fit than measured to ensure that the belt is not too big. On the other hand, thin patients may require a slight overmeasurement to prevent the abrasion of the skin over bony protrusions.1
Fitting the Truss
Immediately before the truss is fitted, the hernia must be reduced, with the patient lying down. If an elastic-band truss is being used, it can be placed directly around the waist with the pad positioned over the reduced hernia. The patient is then asked to stand up before the body band is tightened and the understraps are fixed to the band at each side. A spring truss needs to be handled with more dexterity and manipulation for correct fitting and must not be forced open as this will damage the spring. To fit the truss, it should be passed around the knees and slid upwards over the buttocks to sit just below the iliac crests. If the truss is correctly fitted, the hernia should be retained when the patient coughs.1
Surgical Management
Surgical options available for the management of hernias vary, and the choice depends upon the type and location of hernia.5 The repair procedure almost always involves some type of prosthetic material (i.e., a mesh); because the rate of recurrence is low with the use of prosthetic materials, these are becoming increasingly common.9.10 In some cases a mesh may be avoided; for example, in women of childbearing age, mesh may be avoided because stretching of tissues during pregnancy may result in a recurrent hernia.10 In such cases, the defect may be closed using sutures, although these procedures are generally associated with high recurrence rates.
Owing to the success rates associated with the use of meshes, there are an increasing number of these available on the market. These can be divided into three types:
• Lightweight composite meshes without a barrier, such as Vypro ii and Ultrapro, that are specially designed to reinforce weak tissues for open repair of inguinal hernias
• Absorbable barrier composite meshes, such as Sepramesh and Proceed
• Nonabsorbable barrier composite meshes, such as Bard, Gore-Tex9
When selecting the size of the mesh, it is important that the mesh be wide enough to cover the defect in all directions, since a smaller size may lead to protrusion of the mesh into the defect and result in a recurrence.9
POSTOPERATIVE CARE
The most commonly encountered complications with hernia repair surgery are hematomas, seromas, and wound infection.5 Postoperative care generally involves care of the wound to prevent infections. The length of inactivity following the surgery varies with the type of wound as well as the surgeon’s preference.11,12
ROLE OF THE PHARMACIST
Pharmacists have an essential role to play in the management of patients with hernias as well as in supporting patients who have undergone treatment. In outpatient care, pharmacists may provide advice on the selection of trusses, and they may be measured and fitted at the pharmacy. Pharmacists in all settings are well placed to provide advice on the use of pain medications prior to and after hernia surgery. Pharmacists can instruct patients who are taking OTC or prescription medications to inform the surgeon of this at least 1 week before surgery. For patients who have undergone surgery, pharmacists can ensure that patients have the necessary products to care for the wound appropriately, and provide wound-care tips (depending upon the type of wound and surgical method) and other useful information (Table 1).
CONCLUSION
Abdominal hernias are common, may occur at any age, and are usually managed surgically, typically using a prosthetic mesh. In some cases, trusses may be used after the hernia is reduced in patients unable to withstand surgery or for management prior to surgery. Pharmacists can provide valuable support in ensuring that hernias are effectively treated and that patients are getting the most out of their particular therapy.
REFERENCES
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https://medlineplus.gov/ency/patientinstructions/000274.htm. Accessed July 12, 2017.
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