eMedicine Specialties > Emergency Medicine > Gastrointestinal

Hernias

Bret A Nicks, MD, Assistant Professor, Assistant Medical Director, Department of Emergency Medicine, Wake Forest University Health Sciences
Kim Askew, MD, Assistant Professor, Department of Emergency Medicine, Wake Forest University School of Medicine

Updated: Nov 11, 2009

Introduction

Background

As defined in 1804 by Astley Cooper, a hernia as a protrusion of any viscus from its proper cavity. The protruded parts are generally contained in a sac-like structure, formed by the membrane with which the cavity is naturally lined.¹

Since that time, several different types of abdominal wall hernias have been identified, along with a larger number of associated eponyms. This article reviews the pathophysiology, evaluation, and treatment of most of these hernias from an emergency medicine perspective. Hernias are brought to the attention of an emergency physician either during a routine physical examination for other medical complaints or when the patient has developed a complication associated with the hernia.

See Medscape's Hernia Resource Center.

Pathophysiology

Types of Hernia - Location

Anatomic locations for various hernias.

An indirect inguinal hernia follows the tract through the inguinal canal. This results from a persistent process vaginalis. The inguinal canal begins in the intra-abdominal cavity at the internal inguinal ring, located approximately midway between the pubic symphysis and the anterior iliac spine. The canal courses down along the inguinal ligament to the external ring, located medial to the inferior epigastric arteries, subcutaneously and slightly above the pubic tubercle. Contents of this hernia then follow the tract of the testicle down into the scrotal sac.^2,3,4

Direct hernia

A direct inguinal hernia usually occurs due to a defect or weakness in the transversalis fascia area of the Hesselbach triangle. The triangle is defined inferiorly by the inguinal ligament, laterally by the inferior epigastric arteries, and medially by the conjoined tendon.⁵

Femoral hernia

The femoral hernia follows the tract below the inguinal ligament through the femoral canal. The canal lies medial to the femoral vein and lateral to the lacunar (Gimbernat) ligament. Because femoral hernias protrude through such a small defined space, they frequently become incarcerated or strangulated.⁶

Umbilical hernia

The umbilical hernia occurs through the umbilical fibromuscular ring, which usually obliterates by 2 years of age. They are congenital in origin and are repaired if they persist in children older than age 2-4 years.^2,5

Richter hernia

The Richter hernia occurs when only the antimesenteric border of the bowel herniates through the fascial defect. The Richter hernia involves only a portion of the circumference of the bowel. As such, the bowel may not be obstructed, even if the hernia is incarcerated or strangulated, and the patient may not present with vomiting. The Richter hernia can occur with any of the various abdominal hernias and is particularly dangerous, as a portion of strangulated bowel may be reduced unknowingly into the abdominal cavity, leading to perforation and peritonitis.⁶

Incisional hernia

This iatrogenic hernia occurs in 2-10% of all abdominal operations secondary to breakdown of the fascial closure of prior surgery. Even after repair, recurrence rates approach 20-45%.

Spigelian hernia

This rare form of abdominal wall hernia occurs through a defect in the spigelian fascia, which is defined by the lateral edge of the rectus muscle at the semilunar line (costal arch to the pubic tubercle).^7,8

Obturator hernia

This hernia passes through the obturator foramen, following the path of the obturator nerves and muscles. Obturator hernias occur with a female-to-male ratio of 6:1, because of a gender-specific larger canal diameter. Because of its anatomic position, this hernia presents more commonly as a bowel obstruction than as a protrusion of bowel contents.¹

• Reducible hernia: This term refers to the ability to return the contents of the hernia into the abdominal cavity, either spontaneously or manually.
• Incarcerated hernia: An incarcerated hernia is no longer reducible. The vascular supply of the bowel is not compromised. Bowel obstruction is common.
• Strangulated hernia: A strangulated hernia occurs when the vascular supply of the bowel is compromised secondary to incarceration of hernia contents.

Frequency

United States

• Over 1 million abdominal wall hernia repairs are performed each year, with inguinal hernia repairs constituting nearly 770,000 of these cases.^9,10,11
• Approximately 25% of males and 2% of females have inguinal hernias in their lifetimes; this is the most common hernia in males and females.^11,12
• Approximately 75% of all hernias occur in the groin; two thirds of these hernias are indirect and one third direct.²
• Indirect inguinal hernias are the most common hernias in both men and women; a right-sided predominance exists.
• Incisional and ventral hernias account for 10% of all hernias.⁴
• Only 3% of hernias are femoral hernias.
• The incidence of inguinal hernias in children ranges up to 4.4%, while umbilical hernias occur in approximately 1 out of every 6 children.^10,2
• The incidence of incarcerated or strangulated hernias in pediatric patients is 10-20%; 50% of these occur in infants younger than 6 months.¹⁰

International

• Data from developing countries is limited, therefore, an accurate occurrence value is unavailable. Current epidemiologic assessments postulate that gender and anatomic distribution are similar.

Mortality/Morbidity

Morbidity is secondary to missing the diagnosis of the hernia or complications associated with management of the disease.

• A hernia can lead to an incarcerated and often obstructed bowel.
• The hernia also can lead to strangulated bowel with a compromised blood supply. Reduced strangulated bowel leads to persistent ischemia/necrosis with no clinical improvement. Surgical intervention is required to prevent further complications such as perforation and sepsis.
• Ensuing surgery to repair the hernia or its complications may leave the patient at risk for infection, future hernias, or intra-abdominal adhesions.

Race

• Umbilical hernias occur 8 times more frequently in black infants than in white infants.¹²

Sex

• Approximately 90% of all inguinal hernia repairs are performed on males.¹¹
• Reduction of hernias in females may be complicated by inclusion of the ovary in the hernia.
• Femoral hernias (although rare) occur almost exclusively in women because of the differences in the pelvic anatomy.
• The female-to-male ratio of obturator hernias is 6:1.¹²

Age

• Indirect hernias usually present during the first year of life, but they may not appear until middle or old age.
• Indirect hernias occur more frequently in premature infants compared to term infants. Indirect hernias develop in 13% of infants born before 32 weeks' gestation.¹⁰
• Direct hernias occur in older patients as a result of relaxation of abdominal wall musculature and thinning of the fascia.
• Umbilical hernias usually occur in infants and reach their maximal size by the first month of life. Most hernias of this type close spontaneously by the first year of life, with only a 2-10% incidence in children older than 1 year.¹³

Clinical

History

Patients with hernias present to the emergency department (ED) secondary to a complication associated with the hernia. Hernias also may be detected in the ED on routine physical examination. However, in relation to the chief complaint, the following clinical issues must be considered:

• Asymptomatic hernia
  • Presents as a swelling or fullness at the hernia site
  • Aching sensation (radiates into the area of the hernia)
  • No true pain or tenderness upon examination
  • Enlarges with increasing intra-abdominal pressure and/or standing
• Incarcerated hernia
  • Painful enlargement of a previous hernia or defect
  • Cannot be manipulated (either spontaneously or manually) through the fascial defect
  • Nausea, vomiting, and symptoms of bowel obstruction (possible)
• Strangulated hernia
  • Symptoms of an incarcerated hernia present combined with a toxic appearance.
  • Systemic toxicity secondary to ischemic bowel is possible.
  • Strangulation is probable if pain and tenderness of an incarcerated hernia persist after reduction.
  • Suspect an alternative diagnosis in patients who have a substantial amount of pain without evidence of incarceration or strangulation.

Further anatomic considerations must be assessed in relation to the above clinical findings. The location of the underlying hernia may provide a unique constellation of symptoms with or without specific anatomic findings.

• Femoral hernia
  • Medial thigh pain as well as groin pain are possible because of the position of this hernia.
• Obturator hernia
  • Because this hernia is hidden within deeper structures, it may not present as a swelling.
  • The patient may complain of abdominal pain or medial thigh pain, weight loss, or recurrent episodes of bowel or partial bowel obstruction.
  • Pressure on the obturator nerve causes pain in the medial thigh that is relieved by thigh flexion. This same pain may be exacerbated by extension or external rotation of the hip (Howship-Romberg sign).
• Incisional hernia
  • As these are usually asymptomatic, patients present with a bulge at the site of a previous incision.
  • Lesion may become larger upon standing or with increasing intra-abdominal pressure.

Physical

In general, the physical examination should be performed with the patient in both the supine and standing positions, with and without the Valsalva maneuver. The examiner should attempt to identify the hernia sac as well as the fascial defect through which it is protruding. This allows proper direction of pressure for reduction of hernia contents. The examiner should also identify evidence of obstruction and strangulation.

• When attempting to identify a hernia, look for a swelling or mass in the area of the fascial defect.
  • Place a fingertip into the scrotal sac and advance up into the inguinal canal. If the hernia is elsewhere on the abdomen, attempt to define the borders of the fascial defect.
  • If the hernia comes from superolateral to inferomedial and strikes the distal tip of the finger, it most likely is an indirect hernia.
  • If the hernia strikes the pad of the finger from deep to superficial, it is more consistent with a direct hernia.
• A bulge felt below the inguinal ligament is consistent with a femoral hernia.
• Strangulated hernias are differentiated from incarcerated hernias by the following:
  • Pain out of proportion to examination findings
  • Fever or toxic appearance
  • Pain that persists after reduction of hernia

Causes

Any condition that increases the pressure in the intra-abdominal cavity may contribute to the formation of a hernia, including the following:

• Marked obesity
• Heavy lifting
• Coughing
• Straining with defecation or urination
• Ascites
• Peritoneal dialysis
• Ventriculoperitoneal shunt
• Chronic obstructive pulmonary disease (COPD)
• Family history of hernias¹⁴

Differential Diagnoses

Epididymitis
Hidradenitis Suppurativa
Hydrocele
Lymphogranuloma Venereum
Testicular Torsion

Other Problems to Be Considered

Groin abscess
Hematoma
Lipoma
Lymphadenitis
Pseudoaneurysm
Spermatocele
Tumor
Undescended or retracted testes
Varicocele

Workup

Laboratory Studies

• Complete blood count
  • Results from CBC are nonspecific.
  • Leukocytosis with left shift may occur with strangulation.
• Electrolytes, BUN, creatinine levels
  • Assess the hydration status of the patient with nausea and vomiting.
  • These tests are rarely needed for patients with hernia except as part of a preoperative workup.
• Urinalysis: This test assists with narrowing the differential diagnosis of genitourinary causes of groin pain in the setting of associated hernias.

Imaging Studies

• Imaging studies are not required in the normal workup of a hernia.^4,6
• Ultrasonography can be used in differentiating masses in the groin or abdominal wall or in differentiating testicular sources of swelling.
• If an incarcerated or strangulated hernia is suspected, the following imaging studies can be performed:
  • Upright chest radiograph to exclude free air (extremely rare)
  • Flat and upright abdominal films to diagnose a small bowel obstruction (neither sensitive or specific) or to identify areas of bowel outside the abdominal cavity
• CT scanning or ultrasonography may be necessary in the following cases:
  • To diagnose a spigelian or obturator hernia
  • Inability to obtain a good examination because of body habitus

Treatment

Emergency Department Care

• Reduction of a hernia^2,9,15
  • Provide adequate sedation and analgesia to prevent straining or pain. The patient should be relaxed enough to not increase intra-abdominal pressure or to tighten the involved musculature.
  • Place the patient supine with a pillow under his or her knees.
  • Place the patient in a Trendelenburg position of approximately 15-20° for inguinal hernias.
  • Apply a padded cold pack to the area to reduce swelling and blood flow while establishing appropriate analgesia.
  • Place the ipsilateral leg in an externally rotated and flexed position resembling a unilateral frog leg position.
  • Place 2 fingers at the edge of the hernial ring to prevent the hernial sac from riding over the ring during reduction attempts.
  • Firm, steady pressure should be applied to the side of the hernia contents close to the hernia opening, guiding it back through the defect.
  • Applying pressure at the apex, or first point, that is felt may cause the herniated bowel to "mushroom" out over the hernia opening instead of advancing through it.
  • Consult with a surgeon if reduction is unsuccessful after 1 or 2 attempts; do not use repeated forceful attempts.
  • The spontaneous reduction technique requires adequate sedation/analgesia, Trendelenburg positioning, and padded cold packs applied to the hernia for a duration of 20-30 minutes. This can be attempted prior to manual reduction attempts.
  • Also see Hernia Reduction.

Consultations

Consult a surgeon for the following reasons:^1,16,3

• Inability to reduce the hernia
• Concern for a strangulated bowel and a patient with a toxic appearance
• Patients with comorbid risks for sedation should have a surgeon present for the initial reduction attempt

Medication

For strangulated hernias, start broad-spectrum antibiotics. Antibiotics are administered routinely if ischemic bowel is suspected.

Antibiotics

These agents are to be used if the patient has a strangulated hernia.

Cefoxitin (Mefoxin)

Multiple regimens that cover for bowel perforation and/or ischemic bowel can be used. Cover for both aerobic and anaerobic gram-negative bacteria.

Dosing

Adult

1-2 g IV q8h

Pediatric

80 mg/kg/d IV divided into 4 equal doses q6h

Interactions

Probenecid may increase effects; aminoglycosides or furosemide may increase nephrotoxicity (closely monitor renal function)

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged use or repeated treatment; caution in previously diagnosed colitis

Follow-up

Further Inpatient Care

• All incarcerated or strangulated hernias demand admission and immediate surgical evaluation.

Further Outpatient Care

• Follow-up visits with the general surgeon should be scheduled within the next 1-2 weeks for those patients with easily reducible hernias or with hernias found upon physical examination.
• Discharge patients with umbilical hernias with close follow-up care if the defect is less than 2 cm in diameter and the hernia is not incarcerated or strangulated.
• Educate patients to avoid those activities that increase intra-abdominal pressure.
• Educate patients to return for inability to reduce hernia, increased pain, fever, and vomiting.

Deterrence/Prevention

• Counsel the patient on avoidance of activities that increase intra-abdominal pressure, such as straining at defecation or lifting heavy objects. This may require work or school-related activity restrictions and should be clearly delineated.

Complications

• If strangulation of the hernia is missed, bowel perforation and peritonitis can occur.
• Hernias can reappear in the same location, even after surgical repair.

Prognosis

• The prognosis depends on the type and size of hernia as well as on the ability to reduce risk factors associated with the development of hernias.
• The prognosis is good with timely diagnosis and repair.

Patient Education

• Counsel the patient to avoid those activities that increase intra-abdominal pressure, such as straining at defecation and lifting heavy objects.
• Instruct the patient to apply support to the hernia. Numerous medical device companies have developed support items to assist with this process.
• Even with asymptomatic hernias, early repair (ie, before it enlarges) is preferred. Referral to a general surgeon for discussion about type of repair is warranted as a wide variety of hernia repair options now exist with advent of new meshes and laparoscopy.

Miscellaneous

Medicolegal Pitfalls

• Failure to consider the diagnosis of hernia in patients who present with nausea and/or vomiting
• Diagnosing testicular torsion as a hernia without appropriate evaluation or imaging considerations (puts the testicle at risk)
• Reducing a strangulated bowel without recognizing it (The hernia will be reduced, but the bowel will remain ischemic.)
• Failure to provide adequate instructions for patients with reduced hernias regarding follow-up and the need to return to the ED for worsening or persistent recurrent symptoms

Special Concerns

• Pain after reduction of a hernia may indicate a strangulated hernia, requiring further evaluation by a surgeon.

Multimedia

Media file 1: Anatomic locations for various hernias.

References

1. Eubanks S. Hernias. In: Sabiston DC Jr, ed. Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 1997.

2. Katz DA. Evaluation and management of inguinal and umbilical hernias. Pediatr Ann. Dec 2001;30(12):729-35. [Medline].

3. Levine BJ, Nabha S, Bouzoukis JK. Chronic inguinal hernia. J Emerg Med. May-Jun 1999;17(3):515-6. [Medline].

4. Matthews RD, Neumayer L. Inguinal hernia in the 21st century: an evidence-based review. Curr Probl Surg. Apr 2008;45(4):261-312. [Medline].

5. Scherer LR 3d, Grosfeld JL. Inguinal hernia and umbilical anomalies. Pediatr Clin North Am. Dec 1993;40(6):1121-31. [Medline].

6. Bobrow RS. The hernia. J Am Board Fam Pract. Jan-Feb 1999;12(1):95-6. [Medline].

7. Wants GE. Abdominal wall hernias. In: Schwartz SI, Shires GT, Spencer FC, eds. Principles of Surgery. 6^th ed. 1994.

8. Mensching JJ, Musielewicz AJ. Abdominal wall hernias. Emerg Med Clin North Am. Nov 1996;14(4):739-56. [Medline].

9. Manthey DE. Abdominal hernia reduction. In: Clinical Procedures in Emergency Medicine. 2003.

10. Brandt ML. Pediatric hernias. Surg Clin North Am. Feb 2008;88(1):27-43, vii-viii. [Medline].

11. Rutkow IM, Robbins AW. Demographic, classificatory, and socioeconomic aspects of hernia repair in the United States. Surg Clin North Am. Jun 1993;73(3):413-26. [Medline].

12. Rutkow IM. Epidemiologic, economic, and sociologic aspects of hernia surgery in the United States in the 1990s. Surg Clin North Am. Dec 1998;78(6):941-51, v-vi. [Medline].

13. Kapur P, Caty MG, Glick PL. Pediatric hernias and hydroceles. Pediatr Clin North Am. Aug 1998;45(4):773-89. [Medline].

14. Akbulut S, Cakabay B, Sezgin A. A familial tendency for developing inguinal hernias: study of a single family. Hernia. Aug 29 2009;[Medline].

15. Smith S. Inguinal hernia reduction. In: King C, Henretig FM, eds. Textbook of Pediatric Emergency Procedures. 2^nd ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2008:840-847/87.

16. Ginsburg BY, Sharma AN. Spontaneous rupture of an umbilical hernia with evisceration. J Emerg Med. Feb 2006;30(2):155-7. [Medline].

Keywords

hernia, hernia symptoms, hernia treatment, hernia causes, abdominal wall hernia, indirect inguinal hernia, indirect hernia, direct inguinal hernia, direct hernia, femoral hernia, umbilical hernia, Richter hernia, incisional hernia, spigelian hernia, obturator hernia, reducible hernia, incarcerated hernia, strangulated hernia

Contributor Information and Disclosures

Author

Bret A Nicks, MD, Assistant Professor, Assistant Medical Director, Department of Emergency Medicine, Wake Forest University Health Sciences
Bret A Nicks, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, Christian Medical & Dental Society, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Coauthor(s)

Kim Askew, MD, Assistant Professor, Department of Emergency Medicine, Wake Forest University School of Medicine
Disclosure: Nothing to disclose.

Medical Editor

Richard Lavely, MD, JD, MS, MPH, Lecturer in Health Policy and Administration, Department of Public Health, Yale University School of Medicine
Richard Lavely, MD, JD, MS, MPH is a member of the following medical societies: American College of Emergency Physicians, American College of Legal Medicine, and American Medical Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Eugene Hardin, MD, FAAEM, FACEP, Former Chair and Associate Professor, Department of Emergency Medicine, Charles Drew University of Medicine and Science; Former Chair, Department of Emergency Medicine, Martin Luther King Jr/Drew Medical Center
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Steven C Dronen, MD, FAAEM, Director of Emergency Services, Director of Chest Pain Center, Department of Emergency Medicine, Ft Sanders Sevier Medical Center
Steven C Dronen, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

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