Types of hernia MB

TypeDescriptionRisk of

strangulationIncisionalHerniation through an area weakened

by a scarLow

UmbilicalCongenital defect of the abdominal wall seen in infants as a swelling at the umbilicus

Low

ParaumbilicalAcquired defect above or below the umbilicus

High

EpigastricOften small painful swelling in the midline of abdomen above the umbilicus caused by a defect in linea alba, usually contains extrapentoneal fat

 

FemoralHerniation through the femoral canal which appears 'below and lateral to the pubic tubercle'. More common in women than men

Highest

InguinalTypically seen 'above and medial to the pubic tubercle' swelling is caused by weakness in the abdominal wall in the area of Hasselbach's triangle. Risk of strangulation is low.

Low

IndirectThis is the most common. There are two types. First, congenital, which is caused by a patent processus vaginalis. Second, acquired, herniates through the deep ring and travels along the inguinal canal within the coverings of the spermatic cord. It can go into the scrotum. Risk of strangulation is high.

High

INGIUNAL HERNIA

I. Inguinal Hernia 1. Small Indirect Hernia may slightly tap end of finger

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2. Large Indirect Hernia may be palpable as mass 3. Direct Inguinal Hernia may be felt on pad of finger

B. Inguinal Canal components 1. Internal inguinal ring

a. Lateral to inferior epigastrics b. Landmark: Middle of inguinal ligament

2. Canal a. Follows spermatic cord course in men b. Follows round ligament in women

3. External inguinal ring a. Located at pubic tubercle b. Occurs just above inguinal ligament c. Medial and inferior to internal inguinal ring

II. Epidemiology A. Accounts for 96% groin hernias (other 4% are femoral) B. Bilateral in 20% of cases C. Gender predisposition: Male by 9 to 1 ratio D. Lifetime risk of inguinal herniation: 10%

III. Types A. Indirect inguinal hernia (most common)

1. Course

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a. Hernia sac passes outside Hasselbach's Triangle : IV. Boundaries of Hasselbach's Triangle

A. Medial boundary: Rectus abdominis B. Lateral boundary: Inferior epigastric vessels C. Inferior boundary: Inguinal ligament

1. Herniates via Inguinal Canal : 2. Internal inguinal ring

a. Lateral to inferior epigastrics b. Landmark: Middle of inguinal ligament

3. Canal a. Follows spermatic cord course in men b. Follows round ligament in women

4. External inguinal ring a. Located at pubic tubercle b. Occurs just above inguinal ligament c. Medial and inferior to internal inguinal ring

i. Enters through Internal Inguinal Ring ii. Lateral to inferior epigastrics

d. May result in scrotal hernia in males 5. Pathophysiology

a. Nonobliterated processus vaginalis (congenital) b. Internal abdominal ring weakened fascia

D. Direct inguinal hernia 1. Hernia sac passes within Hasselbach's Triangle 2. Breaches posterior inguinal wall 3. Passes medial to inferior epigastrics 4. Pathophysiology

a. Usually occurs in males b. Acquired deficiency in transversus abdominis muscle

V. Symptoms A. Often asymptomatic (especially in direct hernias) B. Pain or dull sensation in groin

VI. Signs A. Palpable defect or swelling may be present

1. Indirect Hernia may bulge at Internal Inguinal Ring a. Look for bulge site at mid-inguinal ligament

2. Direct Hernia may bulge at External Inguinal Ring a. Look for bulge site at pubic tubercle b. Occurs just above inguinal ligament c. Seen medial and inferior to indirect hernia bulge

B. Distinguishing indirect and direct hernias difficult 1. Experienced clinicians are incorrect in 30% of cases

C. Indirect inguinal hernia palpation difficult in women D. Inguinal hernias difficult to palpate in children

VII. Differential Diagnosis A. See Groin Pain

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VIII. Radiology: Inguinal Ultrasound A. Technique: Ultrasound in various patient positions

1. Supine 2. Upright 3. Valsalva maneuver

B. Efficacy 1. High Test Sensitivity (>90%) 2. High Test Specificity

a. Distinguish Incarcerated Hernia from firm mass IX. Complications

A. Bowel incarceration and strangulation B. Small Bowel Obstruction

FEMORAL HERNIA

I. Epidemiology A. Accounts for 4% of Groin Hernias (96% are inguinal) B. More common in elderly women C. Gender predisposition: Female by 3 to 1 ratio

1. Femoral seen less than Inguinal Hernia even in women II. Pathophysiology

A. Associated with increased intra-abdominal pressure B. Hernia sac bulges into femoral canal

1. Femoral canal is continuation of femoral sheath 2. Femoral canal lies immediately medial to femoral vein

III. Symptoms and Signs A. Groin Pain and tenderness often absent

1. Even strangulation occurs often without pain B. Hernia sac neck location palpable

1. Lateral and inferior to pubic tubercle C. Large femoral hernias may bulge over inguinal ligament

1. May be difficult to distinguish from Inguinal Hernia IV. Differential Diagnosis

A. Inguinal Hernia B. Inguinal Lymphadenopathy C. Varix of Saphenous Vein

1. Thrill on palpation 2. Fills on standing and empties while supine

D. Infectious Bubo 1. Chancroid 2. Syphilis 3. Lymphogranuloma venereum

V. Complications A. Strangulated Hernia (common)

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1. Patients unaware of hernia before strangulation (50%)

EPIGASTRIC HERNIA

II. Pathophysiology A. Type of Ventral Hernia B. Consists of properitoneal fat (rarely peritoneal sac) C. Location

1. Occurs through linea alba (midline) 2. Occurs below xiphoid process and above Umbilicus

III. Symptoms A. Epigastric Pain B. Pulling sensation on leaning backward

IV. Signs A. Difficult to detect in obese patients B. Examine patient in standing position

1. Run finger down course of linea alba 2. Detects small midline Nodule

V. Differential Diagnosis: Epigastric Incarcerated Hernia A. Peptic Ulcer Disease B. Biliary Colic

VI. Management: Surgery A. Suture closure of defect B. Multiple epigastric hernia defects often exist

1. Adequate linea alba exposure required 2. Surgeons explore for occult hernias

INCISIONAL HERNIA

I. Pathophysiology A. Type of Ventral Hernia

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B. Develops in scar of prior laparotomy or drain site C. Risks for post-operative hernia development

1. Vertical scar more commonly affected than horizontal 2. Wound infection 3. Wound dehiscence 4. Malnutrition 5. Obesity 6. Tobacco abuse

II. Signs A. Provocative maneuvers to locate hernia

1. Hernia sac will appear adjacent to scar 2. Hernia sac may be obvious with patient standing 3. Valsalva maneuver 4. Raise head from pillow while supine

B. Large incisional hernias are often asymptomatic C. Often multiple defects present with several rings D. Often Irreducible Hernia due to adhesions

SPIGELIAN HERNIA

I. Pathophysiology A. Type of Ventral Hernia B. Hernia contains peritoneal sac and extreperitoneal fat C. Hernia of posterior lateral abdominal wall fascia

1. Perforates through linea semilunaris 2. Inferior and lateral to Umbilicus

a. Edge of rectus sheath in mid-abdomen b. Immediately below arcuate line

D. Covering tissues 1. Skin 2. Subcutaneous fat 3. External abdominal oblique muscle aponeurosis

II. Symptoms A. Asymptomatic until strangulation

III. Signs: Strangulation A. Examine with patient standing B. Tender mass in abdominal wall C. Localized to 3-5 cm above inguinal ligament

UMBILICAL HERNIA

I. Pathophysiology A. Type of Ventral Hernia

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B. Infants 1. Umbilical ring usually closes by age 2 years

C. Predisposing factors in adults (paraumbilical hernia) 1. Women with multiparity 2. Obesity 3. Cirrhosis with Ascites 4. Increased intrathoracic pressure (e.g. Asthma, COPD)

II. Signs and Symptoms A. Congenital hernia protrudes through firm collar

1. Complete fibrous collar continuous with linea alba 2. Palpable as firm ring

B. Adult paraumbilical hernias 1. Soft hernia covered only by skin 2. May be obscured by subcutaneous fat

III. Complications A. High risk of Incarcerated Hernia, Strangulated Hernia B. May entrap large bowel

CARNETT’S SIGN

Acute Abdominal Pain Evaluation

I. Technique A. Patient lies supine B. Patient tenses abdominal wall

1. Lifts head off table 2. Lifts shoulder off table

II. Interpretation on tensing abdomen A. Intra-abdominal pain source (Negative Carnett's Sign)

1. Abdominal pain decreases with tensing abdomen B. Abdominal Muscle Wall Pain (Positive Carnett's Sign)

1. Pain increases or remains unchanged

ZIEMAN’S EXAMINATION FOR INGUINAL HERNIA

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Indication

Acute Abdominal Pain Evaluation

I. Technique A. Patient lies supine B. Patient tenses abdominal wall

1. Lifts head off table 2. Lifts shoulder off table

II. Interpretation on tensing abdomen A. Intra-abdominal pain source (Negative Carnett's Sign)

1. Abdominal pain decreases with tensing abdomen B. Abdominal Muscle Wall Pain (Positive Carnett's Sign)

1. Pain increases or remains unchanged

HASELLBACH’S TRIANGLE

I. Definition A. Anatomical triangle used to define Inguinal Hernias

II. Boundaries of Hasselbach's Triangle A. Medial boundary: Rectus abdominis B. Lateral boundary: Inferior epigastric vessels C. Inferior boundary: Inguinal ligament

III. Interpretation A. Indirect Inguinal Hernia (out of Hasselbach's Triangle)

1. Enters Inguinal Canal lateral to inferior epigastrics 2. Exits Inguinal Canal inferior to inguinal ligament

B. Direct Inguinal Hernia (within Hasselbach's Triangle) 1. Breaches posterior inguinal wall 2. Passes medial to inferior epigastric vessels

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