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66
Fig. 4.13 Midline abdominal wall hernia with obstruc-
tion (arrows): there is herniation of bowel and uid in the
hernial sac (arrow heads), a sign of incarceration
cavity manually. Incarceration occurs when the
herniation of the contents has occurred through a
small defect due to a narrow neck of the hernial
sac which predisposes the bowel to inammation, obstruction, and ischemia. The role of imaging is to assess the complications secondary to
incarceration (Fig.4.13). Isotropic imaging with
MPR images helps better visualization of hernial
defect and its contents [9].
Hernias, which contain only omentum, can
also show signs of incarceration evident as fat
stranding and free uid in the hernia sac.
Some hernias may show signs of impending
strangulation. Suspicion arises with presence of
free uid in the hernial sac, dilatation of bowel
loops, bowel wall thickening and persistent contrast enhancement of the bowel wall [6, 18]. These
signs indicate the requirement for urgent surgical
decompression to prevent bowel necrosis [6].
4.9.3 Strangulation
Strangulation is an uncommon complication of
anterior abdominal wall hernias, and if it occurs,
has a high surgical mortality ranging from 6 to
23% [19]. Strangulation is the compromised
blood supply to the herniated bowel leading to
ischemia. It occurs secondary to obstruction at
both afferent and efferent loops resulting in a
closed-loop obstruction of the herniated bowel.
R. K. Mathur and N. Goyal
MDCT will reveal closed-loop obstruction
seen as dilated uid-lled herniated bowel loops
with narrowing at both the afferent and efferent
sites [16]. This will result in dilatation of the
proximal bowel loops. The signs of ischemia will
be manifested as bowel wall thickening secondary to mural edema, altered attenuation of bowel
wall ranging from hypo-attenuation in plain
scans to hyper-enhancement in post-contrast
scans. There may be intramural hemorrhage seen
as hyper-attenuation in plain scans. Other ndings are mesenteric fat stranding, engorgement
of mesenteric vessel, and free uid in the hernia
sac. There is a “serrated beak” appearance of the
afferent and efferent limbs at the transition point
(Fig.4.14).
Strangulated hernia is a clinical emergency
and needs prompt surgical management.
4.9.4 Trauma
Trauma in a patient with preexisting abdominal
wall hernia should be evaluated both clinically
and radiologically for injury to hernial sac and
contents. Radiologically, presence of free uid in
hernia sac, bowel wall thickening and abnormal
enhancement of bowel wall, and mesenteric vessel engorgement with mesenteric fat stranding in
and around hernia should raise the suspicion of
trauma to the hernial contents. This also requires
immediate surgical management.
4.9.5 Other Uncommon
Complications
Less common complications include herniation
of intraabdominal viscera, which can be either
solid (e.g., liver, kidneys) or hollow (e.g., stomach, bladder).
Herniation of bladder in inguinal hernia is
not a common phenomenon and carries a high
risk of bladder injury (Fig. 4.15). Unusual
cases of complicated urinary bladder herniation with strangulation are also encountered
seen as thickening of bladder wall with differential enhancement representing impending
ischemia (Fig.4.16).
ab
cd
4 Imaging ofAbdominal Wall Hernias
Fig. 4.14 Anterior abdominal wall defect with signs of strangulations and incarceration: herniation of omental fat and
vessels, increased fat stranding with air pockets within the herniated contents, a denitive sign of ischemia
67
Fig. 4.15 Inguinal hernia: (a–d) axial images showing herniation of part of urinary bladder through the hernial orice.
(e, f) MPR: Inguinal hernia with herniation of part of urinary bladder through it
68
ef
Fig. 4.15 (continued)
a b
R. K. Mathur and N. Goyal
c d
Fig. 4.16 (a, b) Axial images herniation of bladder
through inguinal orice: There is thickening of wall of
herniated urinary bladder, with differential enhancement
of the wall and free uid in the hernial sac which are signs
of strangulation. (c, d) Are MPR in coronal and sagittal
planes showing the hernial defect and signs of obstruction
with impending ischemia. This patient presented with
pain and hematuria
bc
4 Imaging ofAbdominal Wall Hernias
69
In rare cases, intraabdominal tumors or chronic
infectious diseases may herniate through the
abdominal wall or may be a part of the hernial sac.
The extension of intraabdominal inammatory
conditions like tuberculosis and inammatory
bowel disease into the hernia sac may exacerbate
mild symptoms (Figs.4.17 and 4.18).
a
4.9.6 Postoperative Hernial Mesh Appearance
A normal hernial mesh is also visualized following surgical repair and it is important to recognize these implants and be familiar with their
radiological appearance (Fig.4.19).
*
Fig. 4.17 Case of abdominal tuberculosis: lower lateral abdominal wall hernia containing small bowel and ascites. (a)
Axial (b, c) sagittal and coronal MPR images
70
R. K. Mathur and N. Goyal
ac
b
Fig. 4.18 In a case of omental metastasis there is herniation of metastatic deposits through the left lateral abdominal
wall (arrow) seen in CT axial (a, b) and coronal (c) images
a b
®
Þ
Fig. 4.19 (a) Axial (b) sagittal MDCT images showing normal appearance of hernial mesh
ab
4 Imaging ofAbdominal Wall Hernias
71
4.10 Postsurgical Complications
Complications following surgical hernia repair
are not uncommon with an incidence of 50%
depending upon the preoperative hernial sac
contents and integrity of the vasculature and the
operative technique adopted. Accurate detection
of complications by MDCT helps in planning
appropriate treatment [8, 20, 21].
4.10.1 Fluid Collections
Fluid collection is an immediate postoperative
complication of hernial repair. It occurs in about
17% of cases depending upon the surgical technique and type of hernial mesh used [19]. Fluid
collection may be serous uid (seroma) or blood
(haematoma) (Fig.4.20).
Imaging studies reveal fluid collection
at postoperative site superficial or deep to
the anterior abdominal wall. This fluid collection may be loculated, multiloculated, or
tubular, with or without enhancement of the
wall. Fluid levels if present generally indicates
presence of infection. MDCT helps to differentiate between localized fluid collection and
recurrence.
Most seromas resolve spontaneously within
4 weeks. However, if the collection persists
beyond 6weeks, or if there is an increase in size
of collection, or the patient becomes symptomatic secondary to superimposed infection, aspiration is indicated [19, 21]. USG/CT-guided
aspiration/drainage is preferred, and an oblique
approach should be adopted, and a small diameter catheter should be used to avoid resistance
from folds of the mesh.
*
c
Fig. 4.20 Axial (a, b and c) images showing hernial mesh (arrow) and uid collections in subcutaneous tissue depicted
by ∗ represents seroma formation, post hernial repair
72
R. K. Mathur and N. Goyal
4.10.2 Hernial Recurrence
Recurrence post hernia repair constitutes the most
common complication and is related to weakening
of muscles and aging of tissues. The prevalence
of recurrence of hernia depends upon the type of
repair. With open surgical repair without mesh
placement there is up to 30% chance of recurrence. If mesh is used for hernial repair there is a
10% chance of recurrence and in up to 7.5% cases
after laparoscopic repair [19, 21]. Recurrence
usually occurs after 2–3 years and may happen
even after 5 or more years in some cases [19, 20].
MDCT plays a crucial role in evaluation as
clinical evaluation is limited by presence of mesh,
accompanying brosis, obesity and abdominal
distention. Imaging ndings will clearly depict
the site, size, recurrence and contents of hernia.
4.10.3 Infection
Infections in postoperative uid collections
occurs in about 1–5% of cases, if surgery is
delayed and depending on the surgical technique
[20]. Such complications occur more frequently
in older female patients, and if the surgical
repair is done on a strangulated or incarcerated
hernia [19]. Infection manifests early in the
postoperative period (within 2weeks after surgery) and there is high chance of recurrence in
such cases [22].
Infected uid collections may be subcutaneous or deep to the mesh. The differentiation
between the two is important because supercial
infections are managed conservatively, whereas
deep infections are managed with percutaneous
drainage or even removal of the mesh.
Diagnosis is by clinical examination and presence of pain, fever, or leukocytosis. Imaging is
used to conrm the presence, delineate the location and volume of infected collection.
Imaging ndings indicating infection in uid
collection includes the presence of gas or thick
septations in the collection. Post contrast peripheral enhancing rim or inammatory fat stranding in surrounding tissues are other ndings.
Sometimes imaging ndings alone are not specic to assess the nature of a uid collection, and
guided aspiration becomes necessary (Fig.4.21).
a b
Fig. 4.21 Sagittal CT images (a and b): Infection post inguinal hernia repair seen as inammation with thickening of
spermatic cord (∗) and free uid in hernial orice and scrotum (arrow)
ab
4 Imaging ofAbdominal Wall Hernias
73
4.10.4 Mesh-Related Complications
Inammatory changes after hernial repair may lead
to brosis in tissues adjacent to the mesh and is
seen as an irregular shape of the mesh at CT and in
rare cases there is a chance of mesh shrinkage [19].
Intraperitoneal adhesions predispose to small
bowel obstruction. Occasionally, the mesh may
detach and migrate within the abdominal wall [22].
4.10.5 Other Complications
Postoperative complications in inguinal hernias
include ischemia with testicular atrophy and
thickening of the spermatic cord [22]. Transection
or disruption of the vas deferens, hydrocele, osteitis pubis, and thrombosis of adjacent vessels are
other uncommon complications [19, 23].
4.11 Dierential Diagnosis
Several other abdominal wall diseases may pose a
diagnostic dilemma at physical examination and
some may be difcult to differentiate from hernia.
MDCT helps in differentiating these conditions as
CT ndings are usually specic for hernia.
Benign abdominal wall tumors like lipomas,
bromas, hemangiomas, and less-frequently
malignant tumors and metastases can be confused with hernias. Primary sarcomas may also
present as abdominal wall distension or lump and
mimic hernia on clinical examination.
Metastases to abdominal wall are either a
direct invasion by intraabdominal lesions or
occur secondary to vascular spread. Lung tumors
and pancreatic tumors are the most common primary tumors that metastasize to the abdominal
wall. CT reveals solid nodules in the abdominal
wall and should arouse suspicion leading to a
search for an occult primary [24].
Desmoid tumors (musculoaponeurotic bromatoses) are locally invasive dysplastic soft tissue
masses of mesoderm that involve skeletal muscle
and fascial layers. These tumors occasionally
arise in surgical scars or in the mesentery, and they
occur in women during or following pregnancy. A
familial form of desmoid tumor is associated with
Gardner syndrome [25, 26]. These tumors are
large solid enhancing soft tissue masses and can
be easily differentiated from hernia on imaging.
Rectus sheath hematomas may occur as a result
of trauma to the abdominal wall or following a
sudden violent episode of coughing. These may be
secondary to disorders of coagulation or blood dyscrasias. CT demonstrates high attenuating spindle
or lens-shaped lesion/collection on noncontrast
computed tomography (NCCT) within abdominal
wall (Fig.4.22). Hematomas are treated conserva-
*
Fig. 4.22 Clinical mimickers of anterior abdominal wall
hernia; Axial plain (a) and post contrast (b) images showing abdominal wall hematoma (∗) is difcult to differentiate from an obstructed hernia of the abdominal wall. CT
depicts lenticular high attenuation collection representing
blood (a). White arrow shows site of active bleed in a post
contrast scans (b)
74
R. K. Mathur and N. Goyal
tively with gradual regression of size but a residual
mass may persist for several weeks. Rectus sheath
hematomas are not difcult to differentiate from
hernias at MDCT.High attenuation of hemorrhage
on unenhanced images with lack of enhancement,
and gradual resolution on follow-up studies helps
differentiating hematoma from hernia [27, 28].
4.12 Conclusion
Abdominal wall hernias are one of the most common indications for surgery. There may be occult
hernias incidentally detected on imaging or clinically detectable hernias with or without complications. MDCT allows precise detection and
delineation of abdominal wall anatomy and the
site, size and contents of hernia and postoperative
complications if any. Multiplanar reformations
provides detailed images for better understanding
by surgeons which helps them in surgical planning.
References
1. Digestive diseases in the United States: epidemiology
and impact. NIH Publication No. 94-1447. Bethesda:
NIDDK; 1994.
2. Stabile lanora AA, Midiri M, Vinci R, Rotondo A,
Angelelli G. Abdominal wall hernias: imaging with
spiral CT.Eur Radiol. 2000;10:914–9.
3. Harrison LA, Keesling CA, Martin NL, Lee KR,
Wetzel LH. Abdominal wall hernias: review of herniography and correlation with cross sectional imaging. Radiographics. 1995;15:315–32.
4. Shadbolt CL, Heinze SB, Dietrich RB. Imaging
of groin masses: inguinal anatomy and pathologic
conditions revisited. Radiographics. 2001;21 Spec
No:S261–71.
5. Zarvan NP, Lee FT Jr, Yandow DR, Unger
JS. Abdominal hernias: CT ndings. AJR.
1995;164:1391–5.
6. Rettenbacher T, Hollerweger A, Macheiner P, et al.
Abdominal wall hernias: cross sectional imaging signs
of incarceration determined with sonography. AJR.
2001;177:1061–6.
7. Lee GH, Cohen AJ.CT imaging of abdominal hernias.
AJR. 1993;161:1209–13.
8. Miller PA, Mezwa DG, Feczko PJ, Jafri ZH, Madrazo
BL. Imaging of abdominal hernias. Radiographics.
1995;15:333–47.
9. Aguirre DA, Casola G, Sirlin C. Abdominal wall
hernias: MDCT ndings. AJR Am J Roentgenol.
2004;183:681–90.
10. Ghahremani GG, Jimenez MA, Rosenfeld M,
Rochester D. CT diagnosis of occult incisional hernias. AJR Am J Roentgenol. 1987;148:139–42.
11. Raffetto JD, Cheung Y, Fisher JB, etal. Incision and
abdominal wall hernias in patients with aneurysm or
occlusive aortic disease. J Vasc Surg. 2003;37:1150–4.
12. Lassandro F, Iasiello F, Pizza NL, Valente T, etal.
Abdominal hernias: radiological features. World J
Gastrointest Endosc. 2011;3(6):110–7.
13. Killeen KL, Girard S, DeMeo JH, Shanmuganathan
K, Mirvis SE.Using CT to diagnose traumatic lumbar
hernia. AJR Am J Roentgenol. 2000;174:1413–141.
14. Aguirre DA, Santosa AC, Casola G, Sirlin
CB.Abdominal wall hernias: imaging features, complications, and diagnostic pitfalls at multi-detector
row CT.Radiographics. 2005;25:1501–20.
15. Neblett WW 3rd, Pietsch JB, Holcomb GW Jr. Acute
abdominal conditions in children and adolescents.
Surg Clin North Am. 1988;68:415–30.
16. Yu CY, Lin CC, Yu JC, Liu CH, Shyu RY, Chen
CY.Strangulated transmesosigmoid hernia: CT diagnosis. Abdom Imaging. 2004;29:158–60.
17. Macari M, Megibow A. Imaging of suspected
acute small bowel obstruction. Semin Roentgenol.
2001;36:108–17.
18. Astarcioglu H, Sokmen S, Atila K, Karademir
S. Incarcerated inferior lumbar (Petit’s) hernia.
Hernia. 2003;7:158–60.
19. Bendavid R.Complications of groin hernia surgery.
Surg Clin North Am. 1998;78:1089–103.
20. Abrahamson J.Etiology and pathophysiology of primary and recurrent groin hernia formation. Surg Clin
North Am. 1998;78:953–72, vi.
21. Gossios K, Zikou A, Vazakas P, etal. Value of CT
after laparoscopic repair of postsurgical ventral hernia. Abdom Imaging. 2003;28:99–102.
22. Parra JA, Revuelta S, Gallego T, Bueno J, Berrio
JI, Farinas MC. Prosthetic mesh used for inguinal
and ventral hernia repair: normal appearance and
complications in ultrasound and CT. Br J Radiol.
2004;77:261–5.
23. Courtney CA, Lee AC, Wilson C, O’Dwyer
PJ.Ventral hernia repair: a study of current practice.
Hernia. 2003;7:44–6.
24. Stojadinovic A, Hoos A, Karpoff HM, etal. Soft tissue tumors of the abdominal wall: analysis of disease
patterns and treatment. Arch Surg. 2001;136:70–9.
25. Kaplan DB, Levine EA.Desmoid tumor arising in a
laparoscopic trocar site. Am Surg. 1998;64:388–90.
26. Overhaus M, Decker P, Fischer HP, Textor HJ, Hirner
A. Desmoid tumors of the abdominal wall: a case
report. World J Surg Oncol. 2003;1:11.
27. Fukuda T, Sakamoto I, Kohzaki S, etal. Spontaneous
rectus sheath hematomas: clinical and radiological
features. Abdom Imaging. 1996;21:58–61.
28. Moreno Gallego A, Aguayo JL, Flores B, et al.
Ultrasonography and computed tomography reduce
unnecessary surgery in abdominal rectus sheath haematoma. Br J Surg. 1997;84:1295–7.
Part II
Groin Hernia