Pediatric emergency medicine trisk 949
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stretching of the hepatic vessels and multiple area of neovascularity (N ). Note marked
stretching and displacement of the inferior vena cava (I ) with patent portal vein (P ). A, aorta.
ABDOMINAL WALL DEFECTS
Inguinal Hernias and Hydroceles
Indirect inguinal hernia is the most common congenital anomaly that is found in
children. It is approximately 10 times more common in males than in females.
There is a strong familial incidence.
Clinical Manifestations
The child with a hernia may present in different ways. The presentation is
determined by the extent of obliteration of the processus vaginalis during
development. A child may have a completely open hernia sac, which extends
from the internal ring to the scrotum, or a segmental obliteration producing a sac
that is narrow at its proximal end, creating a hydrocele of either the tunica
vaginalis or the spermatic cord. The narrowing of the processus allows the
abdominal fluid to seep into the distal portion of the sac. It then becomes
entrapped and produces what is clinically recognized as a hydrocele. It is often
difficult for this fluid to egress through the narrow patent processus vaginalis
back into the abdominal cavity.
At the time of the embryologic closure of the processus vaginalis, many fetuses
will have some fluid trapped around the testicle in the tunica vaginalis. This is
called a physiologic hydrocele, which is a normal newborn finding. In such cases,
the fluid is gradually absorbed in the first 12 months of life. If, however, an infant
or child develops a hydrocele along the cord in the tunica vaginalis sometime
after birth, it must be assumed the processus vaginalis is still patent and in
communication with the peritoneal cavity. This patent processus vaginalis
represents a hernia sac. Surgical closure of the sac and drainage of the hydrocele
are then indicated on an elective basis.
Many infants and children manifest the classical bulge in the inguinal canal
that occurs during straining or crying. This is caused by a loop of intestine
distending into the hernia sac (or may represent the ovary in a female). Usually,
the hernia sac contents reduce into the abdominal cavity when the straining
ceases. If the prolapsing loop of intestine becomes entrapped in the hernia sac, an
incarceration has occurred. This is a true emergency that could eventually lead to
intestinal obstruction and possibly strangulation of the bowel. For easily reduced
hernias, elective herniorrhaphy should be done shortly after the hernia is
diagnosed.
Hydroceles of the spermatic cord with associated communicating hernias are
sometimes difficult to differentiate from an incarcerated hernia. If an empty
hernia sac can be felt above the hydrocele, the physician can be assured this is an
asymptomatic hernia with an associated hydrocele. However, if there is fullness
above the hydrocele and the mass cannot be reduced, the child should be taken to
the operating room on the assumption that it probably is an incarcerated hernia
that needs to be managed surgically. If there is any uncertainty, US may be useful
to define the hernia. Bowel gas in the hernia sac is not reliably present for
diagnostic reasons.
Management
Fortunately, strangulation of the entrapped loop of bowel in an incarcerated
hernia occurs relatively late so, contrary to adult practice, efforts to reduce the
incarceration without surgery are usually warranted. When a child with an
incarcerated hernia presents in the ED, the child should be given nothing to eat or
drink, given pain medication, and placed in a Trendelenburg position. Often, this
alone will reduce the incarceration. If it does not, bimanual reduction should be
attempted. The fingers and thumb of one hand should compress the internal ring
area, while an effort is made with the other hand “to milk” either gas or fluid out
of the entrapped bowel back into the abdomen. This relieves the pressure and
usually allows the entire loop of bowel to reduce back into the abdominal cavity.
Once the incarcerated hernia is reduced, the child should be admitted or
scheduled for elective surgery at the surgeon’s discretion. Patients who were
vomiting, had guaiac-positive stools, or had significant difficultly reducing
hernias should be admitted for serial abdominal examinations. A day or two
should be allowed to pass to lessen the edema of the area, as well as to allow an
easier and safer elective herniorrhaphy.
Epiploceles (Epigastric Hernias)
If a discrete mass occurs intermittently about one-third of the distance from the
umbilicus to the xiphoid, it is usually the result of a weakness of the linea alba
through which properitoneal fat protrudes. This defect is called epiplocele. Such
defects are fairly common in infants and usually close spontaneously. In older
children, the mass may occasionally be tender. If it becomes excruciatingly
tender, it is a sign that fat has become incarcerated in the hernia. Although there is
no great urgency, these small midline defects should be repaired surgically when
they become symptomatic.
Umbilical Hernias
Umbilical hernias are common in small infants, particularly in AfricanAmericans. Fortunately, most of the hernias tend to close spontaneously, and only
rarely does incarceration occur. Umbilical hernias can be large and unsightly, and
families need reassurance that watchful waiting is the best course. However, if the
umbilical hernia fails to close by the age of 5 to 6 years, surgical repair is
indicated. Umbilical hernias may be repaired earlier if there is a large ring that
shows no signs of diminishing in size over 1 to 2 years, if there is a thinning of
the umbilical skin, or if an incarceration has occurred. Hernias that have a
supraumbilical component tend not to close spontaneously and may be operated
on at an earlier time of life.
Other Umbilical Defects
Omphalomesenteric duct remnants may persist in either of two forms. When the
duct is patent from the ileum to the umbilicus, there is a release of small bowel
contents via an opening in the umbilicus. A second form involves a remnant of
the omphalomesenteric duct that contains a secreting mucosal patch that is
attached to an opening in the center of the umbilicus. Passage of a sterile blunt
probe or instillation of contrast dye under fluoroscopy via the umbilical opening
will usually confirm either of these conditions. Once identified, these remnants
must be excised surgically. In contrast, some infants present with umbilical
granuloma in which an excessive amount of granulation tissue has built up after
separation of the umbilical cord. In these patients, no opening in the granulation
tissue can be seen or felt by means of a probe. These granulomas are usually best
treated by application of silver nitrate to the granulation tissue. After each
treatment, the area should be rinsed thoroughly to prevent burning of adjacent
skin. If the granuloma is allowed to persist, it will eventually epithelialize and
become an umbilical papilloma ( Fig. 116.26 ).
FIGURE 116.26 Omphalomesenteric remnants. Patent omphalomesenteric duct from terminal
ileum to umbilicus (A); closed omphalomesenteric duct with mucosal patch at umbilicus (B);
omphalomesenteric cyst below umbilicus (C); Meckel diverticulum (D); and umbilical
granuloma (E).
