Diagnostic ultrasound ( PDFDrive )

496 PART II Abdominal and Pelvic Sonography
loosening the repaired internal inguinal ring. Inguinal canal
hematomas or seromas that do not compress the spermatic cord
or cause testicular ischemia, on the other hand, can usually be
managed conservatively. Postherniorrhaphy hematomas or
seromas can become secondarily infected and evolve into
abscesses. Stitch granulomas or stitch abscesses can cause pain
(see Fig. 13.54C).
Late recurring pain also has a variety of causes, but recurrent
hernia becomes a greater concern, particularly when the pain
is similar in type to that present before surgery. Late pain etiology
includes recurrent hernia, seroma, hematoma, abscess, traction
on the edges of the mesh, immune reaction to the mesh, spiral
clips, compression of the spermatic cord, and ibrosis and scarring
of the ilioinguinal nerve. Again, dynamic sonography is essential
in evaluating such patients, although it is more diicult than in
patients not previously repaired.
In patients who underwent herniorrhaphy without mesh, the
recurrent hernia is usually of the same type as the original.
However, it is not unusual, even ater tension-free repairs, to
ind a “recurrent” femoral hernia. In such cases, especially ater
external repair, the femoral hernia may have been present before
the repair, but subclinical and unrecognized. his is a major
reason why it is important to look for all types of groin hernias
during dynamic sonography. In our experience, “recurrent”
femoral hernias are less common ater tension-free repairs that
employ mesh, because they usually employ a piece of mesh large
enough to cover the conjoined tendon, internal inguinal ring,
femoral canal, and spigelian area.
In patients whose hernias were repaired with mesh, it is not
possible to determine sonographically whether a recurrent
inguinal hernia is direct or indirect. It is only possible to determine
that it is a recurrent inguinal hernia. he key to inding recurrent
hernias in patients who have mesh in place is to identify the
mesh and then assess for herniations along the edges of the mesh
with dynamic maneuvers. In patients being evaluated for recurrent
hernia, the most useful dynamic maneuver is usually the compression
maneuver with the patient in the upright position.
Because many types of mesh are available, the appearance
varies greatly (Fig. 13.55). In ideal cases, we can actually see the
texture of the mesh. In most cases, however, the mesh can be
seen only as an echogenic line of variable thickness with variable
shadowing or as an area of variable shadowing. Some newer
types of mesh are thin and much more diicult to identify
sonographically. Normal mesh can have folds and can be rolled
at the edges, and it normally bulges mildly outwardly in the
upright position and during Valsalva maneuvers. Patient history
is rarely helpful because patients are unaware of the type of mesh
used.
However, every efort should be made to identify the mesh,
because recurrent hernias do not occur through the center but
rather at the edges of the mesh. Most recurrent hernias occur
along the inferomedial edge of the mesh (Fig. 13.56; Video
13.21), but it is still important to identify the mesh and then
assess the entire periphery of the mesh, because hernias can
occur along any edge of the mesh. Herniation from the edge of
the mesh likely occurs because the afected edge has “pulled
loose” (Fig. 13.57).
he edges of the mesh can be anchored to surrounding connective
tissues with sutures, surgical clips, or special spiral clips.
he sutures and clips hold the mesh in place for about the irst
6 weeks ater surgery. Ater this, ibrosis forms and generally
holds the mesh in place. It is during the irst 6 postoperative
weeks, before the mesh has ibrosed to the anterior abdominal
wall, that mesh is most likely to pull loose from its anchors. In
our experience, this is most likely to occur ater laparoscopic
repairs—not because the repair has been defective or because
laparoscopic repair is less efective, but because the patient feels
“too well, too soon” ater the minimally invasive repair and
resumes activities that put the repair at risk within the irst 6
weeks. Some patients may complain of a tearing sensation during
some movement, followed by the onset of recurrent inguinal
pain, but in most patients the onset is more insidious.
A chronic hematoma or seroma can cause chronic pain, and
its evacuation can relieve the pain. herefore searching for a
hematoma or seroma is a standard part of the postherniorrhaphy
sonogram. Some patients can develop an allergic or hypersensitivity
reaction to the mesh, with a thin seroma localized to the
mesh surface.
When sonography demonstrates no hernia, hematoma, or
seroma, it is important to assess the mesh for tenderness. In
many cases without sonographically demonstrable pathology,
the mesh is tender for a variety of reasons. First, the mesh may
compress the spermatic cord; compressing the mesh will cause
pain that radiates into the scrotum. Second, the mesh may be
placing traction on the ibrosis that holds its edges in place; this
is especially common in patients with signiicant weight gain
since surgery. he mesh usually bulges anteriorly in such cases.
In other cases, the ibrosis that holds the mesh in place has
entrapped nerves, notably the ilioinguinal nerve.
he spiral clips used to anchor the mesh require special
mention. Because these can become tender and a source of
postherniorrhaphy pain, spiral clips are now seldom used.
However, their past popularity means many patients have them.
Spiral clips have a characteristic radiographic and sonographic
appearance (Fig. 13.58). In some postherniorrhaphy patients
with no other sonographically demonstrable pathology, the only
inding is focal tenderness directly over the ofending clip. Surgical
removal of the clip will relieve the pain and tenderness and
typically will not adversely afect the soundness of the repair,
because the edge of the mesh will be held irmly in place by
ibrosis, even ater the clip is removed.
Hernia Complications
Hernia complications include incarceration, obstruction, and
strangulation. Incarcerated hernias are simply hernias that are
nonreducible. Obstructed hernias contain incarcerated bowel
loops that have become mechanically obstructed. Strangulated
hernias contain incarcerated contents with compromised vascularity.
Not all strangulated hernias contain bowel loops; even
preperitoneal fat can become strangulated. Most incarcerated
hernias are neither obstructed nor strangulated, but all obstructed
and strangulated hernias are also incarcerated. Only incarcerated
hernias that are also obstructed or strangulated are surgical
emergencies. Even strangulated hernias that contain only