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Hernia
Margaret Fairhurst, DO
image BASICS
DESCRIPTION
Hernias are areas of weakness or frank disruption of the fibromuscular tissues of the body wall through which intracavity structures pass.
  • Types
    • Inguinal
      • Direct inguinal: acquired; herniation through defect in transversalis fascia of abdominal wall medial to inferior epigastric vessels; increased frequency with age as fascia weakens
      • Indirect inguinal: congenital; herniation lateral to the inferior epigastric vessels through internal inguinal ring into inguinal canal. A “complete hernia” is one that descends into the scrotum, whereas an “incomplete hernia” remains within the inguinal canal.
    • Pantaloon: combination of direct and indirect inguinal hernia with protrusion of abdominal wall on both sides of the epigastric vessels
    • Femoral: herniation that descends through the femoral canal deep to the inguinal ligament. Because of the narrow neck of a femoral hernia, this type of hernia is especially prone to incarceration and strangulation.
    • Incisional or ventral: herniation through a defect in the anterior abdominal wall at the site of a prior surgical incision
    • Congenital: herniation through fascial defect in abdominal wall, secondary to collagen deficiency disease
    • Umbilical: Defect occurs at umbilical ring tissue.
    • Epigastric: protrusion through the linea alba above the level of the umbilicus. These may develop at exit points of small paramidline nerves and vessels, or through an area of congenital weakness in the linea alba.
    • Interparietal (e.g., Spigelian hernia): Hernia sac insinuates itself between layers of the abdominal wall; strangulation common, often mistaken for tumor or abscess.
    • Other: obturator, sciatic, perineal
  • Definitions
    • Reducible: Extruded sac and its contents can be returned to original intra-abdominal position, either spontaneously or with gentle manual manipulation.
    • Irreducible/incarcerated: Extruded sac and its contents cannot be returned to original intraabdominal position.
    • Strangulated: Blood supply to hernia sac contents is compromised.
    • Richter: Partial circumference of the bowel is incarcerated or strangulated. Partial wall damage may occur, increasing potential for bowel rupture and peritonitis.
    • Sliding: wall of a viscus forms part of the wall of the inguinal hernia sac (i.e., R-cecum, L-sigmoid colon)
Geriatric Considerations
Abdominal wall hernias increase with advancing age, with significant increase in risk during surgical repair.
Pregnancy Considerations
  • Increased intra-abdominal pressure and hormone imbalances with pregnancy may contribute to increased risk of abdominal wall hernias.
  • Umbilical hernias are associated with multiple, prolonged deliveries.
EPIDEMIOLOGY
Incidence
  • 75-80% groin hernias: inguinal and femoral
  • 2-20% incisional/ventral, depending on whether a prior surgery was associated with infection or contamination
  • 3-10% umbilical, considered congenital
  • 1-3% other
  • Groin
    • 6-27% lifetime risk in adult men
    • Two-peak theory: most inguinal hernias present before 1 year of age or after 55 years of age
    • ˜50% of children <2 years of age will have a patent processus vaginalis, decreasing to 40% after age 2 years. Only between 25% and 50% will become clinically significant.
    • Inguinal hernia found in <5% of newborns but male-to-female ratio is 10:1.
    • Increased incidence in premature infants
    • Increased incidence in patients with abdominal aortic aneurysms
    • Femoral <10% of all groin hernias, 40% present as a surgical emergency
  • Incisional/ventral: ˜10-23% of abdominal surgeries complicated by an incisional hernia, most common in upper midline incisions.
  • Incidence ratio: male = female
  • Umbilical: 10-20% of newborns; most close by 5 years of age
Prevalence
  • Groin and inguinal hernias are more prevalent in men.
  • Femoral and umbilical hernias are more prevalent in women.
  • Most inguinal hernias are indirect in both genders.
  • Incisional/ventral hernias are more prevalent in obese persons, as well as in smokers. The opposite may be true for inguinal hernias.
ETIOLOGY AND PATHOPHYSIOLOGY
Loss of tissue strength and elasticity, especially with aging or congenital defect in abdominal fascia resulting in a defect in the fascia of the abdominal wall. Most pediatric hernias are congenital defects (e.g., patent processus vaginalis), whereas most adult hernias are a result of acquired weakness in the tissues of the anterior abdominal wall.
Genetics
No known genetic pattern
RISK FACTORS
  • Increased abdominal pressure, coughing, heavy lifting, constipation, pregnancy, ascites, prostatism, obesity, advancing age (loss of tissue turgor), smoking, steroid use, low birth weight, prematurity
  • Age: Femoral and scrotal hernias, along with recurrent groin hernias, are associated with increased risk for acute hernia surgery.
COMMONLY ASSOCIATED CONDITIONS
Obesity, chronic obstructive pulmonary disease, multiple abdominal surgeries, pregnancy, advanced age, Ehlers-Danlos syndrome, Marfan syndrome, polycystic kidney disease (PKD), osteogenesis imperfecta, Down syndrome, abdominal aortic aneurysm
image DIAGNOSIS
PHYSICAL EXAM
  • Exam should initially occur with patient standing. During palpation, the patient should be instructed to cough, strain, or perform Valsalva maneuver so the extent of intracavitary content movement can be appreciated. Exam should also be performed with patient in supine position.
  • Inguinal (superior to inguinal ligament)
    • Direct inguinal hernia: Finger in inguinal canal finds defect of the transversalis fascia as a deep (posterior to anterior) bulge palpated by pad of finger with increased intra-abdominal pressure.
    • Indirect inguinal hernia: Finger in inguinal canal finds a persistent process vaginalis as a bulge (lateral to medial) palpated by fingertip; it may extend down into scrotum.
  • Femoral (inferior to inguinal ligament): bulge in upper middle thigh; neck of the sac will protrude lateral to and below a finger placed on the pubic tubercle.
  • Umbilical: palpable protrusion at umbilicus
  • Incisional/ventral: palpable protrusion at site of prior abdominal incision or midline superior to the umbilicus
  • Epigastric: palpable protrusion that occurs off midline above umbilicus
DIFFERENTIAL DIAGNOSIS
Lymphadenopathy, hydrocele, lipoma, varices, cryptorchidism, abscess, tumor, sports hernia (athletic pubalgia), pelvic fractures, adductor tears, omphalomesenteric duct, urachal cyst
DIAGNOSTIC TESTS & INTERPRETATION
Hernia evaluation rarely requires imaging; reserve for suspected abdominal hernia or unclear diagnosis. Plain radiographs to rule out obstruction
  • Ultrasound (US) can be used to assess inguinal hernias.
  • CT or tangential radiography for incisional and abdominal wall hernias and postsurgical patients with complaints of abdominal pain
  • Herniography is no longer recommended.
Pediatric Considerations
There is insufficient evidence for contralateral exploration in pediatric patients, except using US.
Follow-Up Tests & Special Considerations
For occult hernias not well appreciated on exam or with imaging, diagnostic laparoscopy may be beneficial.
image TREATMENT
  • Elective setting
    • Elective surgical repair is associated with significantly lower morbidity and mortality.
  • Acute setting
    • Pain management is recommended for symptomatic hernias.
    • Strangulated hernias should be surgically repaired as early as possible to prevent complications such as necrosis and viscus perforation.
    • P.473

    • Manual reduction of incarcerated hernia improves outcomes by allowing for elective repair after reduction of acute swelling and inflammation.
    • Complication rate is nearly 20 times greater in emergent repair of pediatric inguinal hernias than elective procedure.
    • Acute hernia repair carries a higher morbidity and lower survival rate.
    • Laparoscopic repair of incisional/ventral hernia (IVH) is safe, with fewer complications and shorter hospital stays and possibly a shorter surgical time. However, postoperative pain and recurrence rates are similar for both techniques.
    • For patients undergoing repair, operative times are shorter for laparoscopic totally extraperitoneal repair then with open mesh repair and without any difference in complication rates (1)[B].
MEDICATION
  • Antibiotics: Antibiotic prophylaxis did not reduce wound infections after groin hernia repairs.
  • Pain: Local anesthetic during surgical repair results in significant reduction of postoperative pain. Tension-free procedures, such as Lichtenstein, may be performed under local anesthesia.
ADDITIONAL THERAPIES
Geriatric Considerations
Use of a truss (external supportive device) for direct inguinal hernias is common; no data exist regarding efficacy.
ISSUES FOR REFERRAL
Warn patients of symptoms or signs of incarceration or strangulation (acute abdominal pain, fever, bloody bowel movements), which mandate immediate selfreferral to emergency room.
SURGERY/OTHER PROCEDURES
All inguinal hernias should be surgically repaired, but watchful waiting in the asymptomatic patient is a safe option if significant comorbidities may compromise emergent repair.
  • Incarceration and strangulation are absolute indications for hernia repair.
  • Contraindications: patients who are not surgical candidates based on cardiovascular risk factors
    • Elective repair should be avoided in pregnant patients or those with active infections.
  • Special considerations
    • Umbilical hernias <0.5 cm usually obliterate and can be managed by observation.
    • Umbilical hernias in children age 2 to 4 years may be observed, as there is a high rate of spontaneous closure.
    • Operative times and complication rates are similar when comparing single-incision laparoscopic inguinal hernia repair versus traditional multiport laparoscopic repair (2)[B].
    • “Watchful waiting” is recommended in pregnancy. Elective postpartum hernia repair provided similar results to the nonpregnant population without increased risk of incarceration or strangulation before or during delivery.
    • Women had lower recurrence rates with laparoscopic methods than with Lichtenstein open method.
    • Ascites is not a strict contraindication for surgical repair. There is a greater risk of strangulation and complication without repair than the increased risks associated with repair in the presence of ascites.
    • The more emergent hernia operations can be performed using the same methods for nonacute situations. However, incarceration with strangulation may require laparotomy with partial bowel resection.
  • Gold standard
    • Inguinal hernia
      • Open: Lichtenstein with mesh (37%) or mesh plug (34%): decreased recurrence rates
      • Laparoscopic (14%) with mesh: decreased hospital stay and postoperative pain
        • Requires general anesthesia
        • Transabdominal preperitoneal (TAPP) versus total extraperitoneal (TEP)
      • Pediatric: Laparoscopic percutaneous repair is an efficient, safe, and effective alternative to open repair. It is associated with reduced operative times without an increase in complication or recurrence rates (3)[B].
    • Incisional/ventral
      • Laparoscopic repair is effective for most patients with primary or recurrent ventral hernias; it is associated with a <10% recurrence rate.
    • Umbilical
      • Pediatric: open excision and closure with suture
      • Adult: Open repair with mesh or plug may reduce hernia recurrence.
  • Newer techniques
    • Prolene hernia system
    • Biologic wound closure system: reduced recurrence in contaminated procedures
  • Complications
    • Recurrence
    • Seromas
    • Postoperative pain, temporary or chronic: improved in laparoscopic approach versus open
    • Wound infection
    • Injury to cord structures in inguinal herniorrhaphy; with nerve injury, most symptoms will resolve.
image ONGOING CARE
PATIENT EDUCATION
  • Cleveland Clinic: http://my.clevelandclinic.org/disorders/hernia/hic_hernia.aspx
  • Umbilical hernias: Boston Children's Hospital: http://www.childrenshospital.org/az/Site1018/mainpageS1018P0.html
PROGNOSIS
  • Groin (pediatric): low recurrence rates (<3%) with surgical treatment; may spontaneously resolve in infants
  • Groin (adult): ≥1% per year risk of bowel strangulation without surgical treatment; 0-10% postoperative recurrence rates, depending on surgeon's experience level and method
  • Incisional/ventral: 3-5% postoperative occurrence: 2-17% postrepair recurrence, increased to 20-46% in larger hernias
  • Umbilical (pediatric)
    • High rate of spontaneous resolution
    • Hernia less likely to close further in older children and in children with larger defects
  • Umbilical (adult): up to 11% postoperative recurrence rate
  • Epigastric: most will ultimately become incarcerated and/or strangulated without surgical treatment. Recurrence is high due to frequency of missed defects during repair.
REFERENCES
1. Winslow ER, Quasebarth M, Brunt LM. Perioperative outcomes and complications of open vs laparoscopic extraperitoneal inguinal hernia repair in a mature surgical practice. Surg Endosc. 2004:18(2): 221-227.
2. Buckley FP III, Vassaur H, Monsivais S, et al. Comparison of outcomes for single-incision laparoscopic inguinal herniorrhaphy and traditional three-port laparoscopic herniorrhaphy at a single institution. Surg Endosc. 2014;28(1):30-35.
3. Timberlake MD, Herbst KW, Rasmussen S, et al. Laparoscopic percutaneous inguinal hernia repair in children: review of technique and comparison with open surgery [published online ahead of print May 13, 2015]. J Pediatr Urol. 2015;11(5): 262.e1-262.e6
Additional Reading
&NA;
  • Abi-Haidar Y, Sanchez V, Itani KM. Risk factors and outcomes of acute versus elective groin hernia surgery. J Am Coll Surg. 2011;213(3):363-369.
  • Brandt ML. Pediatric hernias. Surg Clin North Am. 2008;88(1):27-43, vii-viii.
  • Buch KE, Tabrizian P, Divino CM. Management of hernias in pregnancy. J Am Coll Surg. 2008;207(4): 539-542.
  • Matthews RD, Neumayer L. Inguinal hernia in the 21st century: an evidence-based review. Curr Probl Surg. 2008;45(4):261-312.
  • Ng TT, Hamlin JA, Kahn AM. Herniography: analysis of its role and limitations. Hernia. 2009;13(1):7-11.
  • Rosemar A, Angerås U, Rosengren A. Body mass index and groin hernia: a 34-year follow-up study in Swedish men. Ann Surg. 2008;247(6):1064-1068.
  • Sajid MS, Bokhari SA, Mallick AS, et al. Laparoscopic versus open repair of incisional/ventral hernia: a meta-analysis. Am J Surg. 2009;197(1):64-72.
  • Snyder CL. Current management of umbilical abnormalities and related anomalies. Semin Pediatr Surg. 2007;16(1):41-49.
See Also
&NA;
Algorithms: Abdominal Pain, Lower; Intestinal Obstruction; Pelvic Pain
Codes
&NA;
ICD10
  • K46.9 Unspecified abdominal hernia without obstruction or gangrene
  • K40.90 Unil inguinal hernia, w/o obst or gangr, not spcf as recur
  • K41.90 Unil femoral hernia, w/o obst or gangrene, not spcf as recur
Clinical Pearls
&NA;
  • Inguinal
    • Direct inguinal: acquired; herniation through defect in transversalis fascia of abdominal wall medial to inferior epigastric vessels
    • Indirect inguinal: congenital; herniation lateral to the inferior epigastric vessels; a “complete hernia” descends into the scrotum; an “incomplete hernia” remains within the inguinal canal.
  • Pantaloon: combination of direct and indirect inguinal hernia
  • Femoral: descends through the femoral canal deep to the inguinal ligament
  • Incisional or ventral: iatrogenic, herniation through a defect at site of a prior surgical incision
  • Umbilical: Defect occurs at umbilical ring tissue.