Hernia is a protrusion of any viscus from its normal cavity. Hernias are classified by anatomic location, hernia contents, and the status of those contents (eg, reducible, incarcerated, or strangulated). Hernia is typically used to describe a protrusion of bowel through the abdominal wall. The most common abdominal hernias are inguinal, ventral, and femoral hernias (Fig. 46-1).
Predisposing factors include family history, lack of developmental maturity, undescended testes, genitourinary abnormalities, conditions that increase intraabdominal pressure (eg, ascites or pregnancy), chronic obstructive pulmonary disease, and surgical incision sites.
Most hernias are detected on routine physical examination or inadvertently by the patient. When the contents of a hernia can be easily returned to their original cavity by manipulation, the hernia is defined as reducible. A hernia becomes incarcerated when its contents are not reducible. Incarcerated hernias may lead to bowel obstruction and strangulation. Strangulation refers to vascular compromise of the incarcerated contents and is an acute surgical emergency. When not relieved, strangulation may lead to gangrene, perforation, peritonitis, and septic shock.
Symptoms other than an obvious protruding mass from the abdominal wall include localized pain, nausea, and vomiting. Signs of strangulation include severe pain and tenderness, induration and erythema over the site. Children may exhibit irritability and poor feeding. Careful evaluation for obstruction is essential.
Physical examination is the predominant means of diagnosis. Laboratory testing is of minimal value. Ultrasonographic detection of hernias is operator and body habitus dependent, but can be helpful in pediatric and pregnant patients where radiation exposure is a concern (Fig. 46-2). Computed tomography remains the best radiographic test for the evaluation of hernias.
Ultrasonographic detection of incarcerated hernia. An incarcerated obturator hernia is demonstrated deep in the femoral region. It locates posterior to the pectineus muscle (arrows) and medial to the femoral artery (A) and vein (V).
(Reproduced with permission from Ma OJ, Mateer JR, Blaivas M (eds): Emergency Ultrasound, 2nd ed. Copyright © 2008 The McGraw-Hill Companies, All rights reserved.)
The differential diagnosis of a groin mass includes direct or indirect hernia, testicular torsion, tumor, groin abscess, hydrocele, varicocele, and hidradenitis. In children, retracted or undescended testes may be mistaken for inguinal hernias.
Do not attempt reduction if signs of strangulation exist so as not to introduce dead bowel into the abdomen.
To reduce a hernia, (a) place the patient in Trendelenburg, (b) externally rotate and flex the ipsilateral leg into the frog-leg position, (c) administer adequate analgesia or procedural sedation; children will require procedural sedation, (d) place a padded ice pack to reduce swelling and blood flow to the area, and (...