Hernias

[Section Outline]

Description
Epidemiology
Etiology

Author:

Sean P.Dyer

Description

Protrusion of bodily structure or organ through a defect in tissues normally containing it
Abdominal wall hernia due to weakness or disruption of fibromuscular layer of abdominal wall
Classified by region (ventral, groin, pelvic, flank) or etiology such as external (hernia protrudes visibly to outside), internal (herniated contents occur within body cavity), or interparietal (hernial sac contained within abdominal wall)
Groin:
- Indirect inguinal hernia:
  - Results from persistent process vaginalis
  - Peritoneal contents herniate through internal ring
  - Right side more common than left
  - 27% lifetime risk of repair for men; 3% for women
- Direct inguinal hernia:
  - Due to weakness or defect in transversalis area in Hesselbach triangle:
  - Inguinal ligament inferiorly
  - Inferior epigastric vessels laterally
  - Lateral border of rectus abdominis medially
- Femoral hernia:
  - Peritoneum herniates into femoral canal beneath inguinal ligament
  - Incarceration frequent due to protrusion through small orifice
  - Internal: Diaphragmatic, hernias from mesenteric/omental tears, foramen of Winslow
Flank:
- Lumbar hernia:
  - Occur in superior and inferior lumbar triangle of posterior abdominal wall (incarcerate in 25% cases)
  - Usually middle-aged men, chronic low back pain with palpable mass
Pelvic:
- Obturator hernia:
  - Passes through obturator membrane and exits beneath pectineal muscle
Ventral:
- Incisional hernia:
  - Resultant breakdown of previous surgical fascial closure
- Epigastric hernia:
  - Midline between xiphoid and umbilicus
- Spigelian hernia:
  - Protrusion through oblique fascia lateral to rectus abdominis muscle
- Umbilical hernia:
  - Congenital failure of umbilical ring to close
  - Protrusion through fibromuscular umbilical ring/umbilicus
  - Often incarcerate in adults, although rarely in infants (often spontaneously close)
  - 20-45% recurrence rate

Epidemiology

Hernia repair (herniorrhaphy) extremely common general surgical procedure (>750,000 performed in the U.S. annually)
Prevalence: 5% of population
Groin and femoral hernias account for 85% of hernias:
- Umbilical and incisional hernias account for additional 10%

Etiology

Reducible hernia:
- Protruding structures can be returned to abdominal cavity
Incarcerated hernia:
- Contents of hernia cannot be manipulated back into abdominal cavity
Strangulated hernia:
- Vascular compromise of entrapped bowel contained within hernia leading to ischemia and gangrene (skin color changes may be apparent)
- Higher risk in hernias with small openings and large sacs
- Signs and symptoms of bowel obstruction or ischemia may occur (nausea/vomiting, fever, leukocytosis)

Diagnosis ⬆ ⬇

[Section Outline]

Signs and Symptoms
Essential Workup
Diagnostic Tests & Interpretation
Differential Diagnosis

Signs and Symptoms

History

Pain and swelling:
- Localized to region of hernia
Persistent pain, vomiting, fever may indicate:
- Incarceration
- Strangulation
- Bowel obstruction

Physical Exam

Vital signs:
- Frequently normal
- Tachycardia with pain, dehydration, infection
- Hypotension with dehydration, strangulation, infection/sepsis
- Fever with infection/sepsis
- Skin color changes with strangulation
Inguinal hernia:
- Pain:
  - Localized to inguinal region
  - Exacerbated by straining/positional changes
  - Relieved by rest
- Swelling:
  - Males: Bulge in scrotum
  - Females: Bulge immediately inferior to inguinal ligament or in labia
- Swelling of spermatic cord, scrotum, or testes
- Valsalva maneuver performed with finger directed toward internal ring - may allow hernia sac to descend against finger
Femoral hernia:
- Pain/swelling:
  - Localized to femoral orifice inferior to inguinal ligament
Incisional hernia:
- Pain/swelling:
  - Localized to previous incision/scar
Obturator hernia:
- Nonspecific abdominal pain
- Intermittent intestinal obstruction
- Weight loss
- Pain:
  - Owing to pressure on obturator nerve from hernia (Howship-Romberg sign)
  - Along medial thigh and radiating to hip
  - Relieved with thigh flexion
  - Exacerbated by hip extension, adduction, or external rotation
Spigelian hernia:
- Abdominal pain/mass along anterior abdominal wall
- Increased pain with maneuvers increasing intra-abdominal pressure
- Intermittent bowel obstruction
- Palpable mass along Spigelian line:
  - Convex line extending from costal arch to pubic tubercle along lateral edge of rectus muscle

Pediatric Considerations

Diagnosis often difficult:
- Parents describe bulge in inguinal area often no longer present at time of exam
- Incarcerated hernias may present with irritability, abdominal pain, or intermittent vomiting
Incidence of incarceration/strangulation is 10-20%:
- >50% in patients younger than 6 mo of age
- Incidence of incarceration higher in girls than boys
Umbilical hernias:
- Strangulation and incarceration rare
- Most close spontaneously
- Most surgeons will delay closure until 4 yr of age, although timing is controversial
Inguinal hernias (consider hydrocele):
- If hydrocele, neck narrows at external inguinal canal without extension into inguinal canal

Pregnancy Prophylaxis

Hernias uncommon during pregnancy, manifesting before or during
Inguinal hernia: 1:1,000-3,000 incidence, 75% occurring in multiparas
Recognition of emergent situations (incarceration, strangulation) may be a diagnostic and management challenge
No consensus exists regarding treatment of unreducible hernia during pregnancy; complications during pregnancy may outweigh elective hernioplasty and emergent surgical consultation recommended

Geriatric Considerations
Higher risk of bowel resection if >65 yr of age with incarcerated hernias Higher postoperative pulmonary and cardiovascular complications

Essential Workup

Careful history and physical exam:

Palpate inguinal/femoral area for tenderness/masses
Attempt exam with the patient stand ing or straining (Valsalva maneuver) if hernia not obvious
Pelvic exam in women to evaluate gynecologic etiologies of groin pain

Diagnostic Tests & Interpretation

Lab

CBC:
- Leukocytosis with strangulation
Electrolytes, BUN/creatinine, glucose:
- If vomiting/dehydration
Urinalysis:
- Genitourinary causes of groin pain

Imaging

None needed if reducible inguinal protrusion on exam
Plain abdominal radiographs:
- Obstructive bowel pattern with incarceration or strangulation
US:
- For identifying unknown masses in groin, scrotum, or abdominal wall
- May be difficult in obese patients
CT:
- To diagnose obturator or Spigelian hernia
- Consider in symptomatic patients in whom body habitus precludes adequate physical exam or US study

Differential Diagnosis

Hydrocele
Varicocele
Lymphadenitis
Testicular torsion
Testicular tumor
Undescended testis
Renal calculi
UTI
Ovarian torsion
Lymphogranuloma venereum
Abdominal wall hematoma
Abdominal wall tumor
Abdominal wall abscess

Treatment ⬆ ⬇

[Section Outline]

Initial Stabilization/Therapy
ED Treatment/Procedures
Medication

Initial Stabilization/Therapy

0.9% NS IV fluid resuscitation for dehydration, bowel strangulation, obstruction, or sepsis:
- Adults: 1-L bolus
- Peds: 20-mL/kg bolus

ED Treatment/Procedures

Incarcerated or strangulated hernias:
- IVFs
- Nasogastric tube (NGT)
- Surgical consultation
- Preoperative broad-spectrum antibiotics for strangulated hernia (controversial)
Hernia reduction procedure:
- IV sedation (benzodiazepines) and analgesia (opiates) if necessary
- Place patient in Trendelenburg position
- For spontaneous reduction, allow 20-30 min
- For manual reduction:
  - Place constant, gentle pressure on hernia
  - For inguinal hernias, achieve reduction by putting fingers of 1 hand on internal ring while gently pulling then pressing on hernia distal to external ring
- Obtain surgical consultation if reduction is unsuccessful after 1 or 2 attempts
- Contraindications to reduction include:
  - Fever
  - Leukocytosis
  - Signs of strangulation
- Complications:
  - Introduction of strangulated bowel into abdomen precipitating systemic infection
  - Further ischemia/necrosis occurs with no clinical improvement
- Reduction in girls may be more difficult if ovary encased within hernia

Medication

Analgesics:
- Morphine sulfate: 2-10 mg per dose (peds: 0.1-0.2 mg/kg q2-4h) IV/IM/SC
- Fentanyl: 1-4 mcg/kg (peds: 1-4 mcg/kg) IV
Sedatives:
- Lorazepam: 1-2 mg IV
- Midazolam: 1-2 mg (peds: 0.07 mg/kg) IV

Follow-Up ⬆ ⬇

[Section Outline]

Disposition
Follow-up Recommendations

Disposition

Admission Criteria

Strangulated hernias require immediate surgical intervention
Incarcerated hernias require admission for urgent surgical intervention
Intestinal obstruction
Peritonitis
Vomiting/dehydration
Uncontrolled pain

Discharge Criteria

After successful reduction has been achieved and patient asymptomatic

Issues for Referral

Referral to surgery with instructions to return if recurrent persistent pain, fever, vomiting

Follow-up Recommendations

General surgery referral

Pearls and Pitfalls ⬆ ⬇

Failure to recognize signs and symptoms of an incarcerated or strangulated hernia
Forcing reduction of incarcerated hernia
Reintroducing strangulated bowel back into abdominal cavity

Additional Reading ⬆ ⬇

DericiH, UnalpHR, BozdagAD, et al. Factors affecting morbidity and mortality in incarcerated abdominal wall hernias . Hernia. 2007;11(4): 341-346.
NicksBA. Hernias: Treatment & medication . Available at http://emedicine.medscape.com/article/775630-treatment. Accessed on February 2013.
Sanchez-ManuelFJ, Lozano-GarcíaJ, Seco-GilJL. Antibiotic prophylaxis for hernia repair . Cochrane Database Syst Rev. 2007;18(3):CD003769.
StrangeCD, BirkemeierKL, SincleairST, et al. Atypical abdominal hernias in the emergency department: Acute and non-acute . Emerg Radiol. 2009;16(2):121-128.
WangKS; Committee on Fetus and Newborn, American Academy of Pediatrics, American Academy of Pediatrics. Assessment and management of inguinal hernia in infants . Pediatrics. 2012;130(4):768-773.

See Also (Topic, Algorithm, Electronic Media Element)

Abdominal Pain

Codes ⬆

ICD9

553.00 Femoral hernia without mention of obstruction of gangrene, unilateral or unspecified(not specified as recurrent)
553.9 Hernia of unspecified site without mention of obstruction or gangrene
550.90 Inguinal hernia, without mention of obstruction or gangrene, unilateral or unspecified (not specified as recurrent)
553.20 Ventral, unspecified, hernia without mention of obstruction or gangrene
552.00 Femoral hernia with obstruction, unilateral or unspecified (not specified as recurrent)
552.02 Femoral hernia with obstruction, bilateral (not specified as recurrent)
552.1 Parumbilical hernia specified as incarcerated, irreducible, strangulated, or causing obstruction
552.21 Postoperative hernia specified as incarcerated, irreducible, strangulated, or causing obstruction
552.29 Epigastric hernia specified as incarcerated, irreducible, strangulated, or causing obstruction
552.9 Hernia of unspecified site, with obstruction
553.02 Femoral hernia without mention of obstruction or gangrene, bilateral (not specified as recurrent)
553.1 Umbilical hernia without mention of obstruction or gangrene
553.21 Incisional hernia without mention of obstruction or gangrene
553.29 Other ventral hernia without mention of obstruction or gangrene
553.8 Hernia of other specified sites without mention of obstruction or gangrene

ICD10

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
K46.9 Unspecified abdominal hernia without obstruction or gangrene
K43.9 Ventral hernia without obstruction or gangrene
K40.00 Bi inguinal hernia, w obst, w/o gangrene, not spcf as recur
K40.20 Bi inguinal hernia, w/o obst or gangrene, not spcf as recur
K40.30 Unil inguinal hernia, w obst, w/o gangr, not spcf as recur
K41.00 Bi femoral hernia, w obst, w/o gangrene, not spcf as recur
K41.20 Bi femoral hernia, w/o obst or gangrene, not spcf as recur
K41.30 Unil femoral hernia, w obst, w/o gangrene, not spcf as recur
K42.0 Umbilical hernia with obstruction, without gangrene
K42.9 Umbilical hernia without obstruction or gangrene
K43.0 Incisional hernia with obstruction, without gangrene
K43.2 Incisional hernia without obstruction or gangrene
K43.6 Other and unsp ventral hernia with obstruction, w/o gangrene
K45.8 Oth abdominal hernia without obstruction or gangrene

SNOMED

52515009 Hernia of abdominal cavity (disorder)
50063009 Femoral hernia
396232000 inguinal hernia (disorder)
414474001 Incisional hernia of anterior abdominal wall (disorder)
236037000 incisional hernia (disorder)
289260002 Epigastric hernia (disorder)
290187002 Spigelian hernia (disorder)
396347007 Umbilical hernia (disorder)
65626001 indirect inguinal hernia (disorder)
73147001 direct inguinal hernia (disorder)
8377001 Hernia, with obstruction (disorder)

section name header

Basics ⬇

Diagnosis ⬆ ⬇

History

Physical Exam

Pediatric Considerations

Pregnancy Prophylaxis

Geriatric Considerations

Lab

Imaging

Treatment ⬆ ⬇

Follow-Up ⬆ ⬇

Admission Criteria

Discharge Criteria

Issues for Referral

Pearls and Pitfalls ⬆ ⬇

Additional Reading ⬆ ⬇

Codes ⬆