© Springer International Publishing Switzerland 2016
Abe Fingerhut, Ari Leppäniemi, Raul Coimbra, Andrew B. Peitzman, Thomas M. Scalea and Eric J. Voiglio (eds.)Emergency Surgery Course (ESC®) Manual10.1007/978-3-319-21338-5_2525. Surgical Emergencies Related to Abdominal Wall Hernias
(1)
Division of Trauma, Emergency Surgery, and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
(2)
Surgery, Harvard Medical School, Division of Trauma, Emergency Surgery, and Critical Care, Massachusetts General Hospital, Boston, MA, USA
25.1 Surgical Anatomy
25.1.1 Abdominal Wall
25.1.2 Inguinal Region
25.1.3 Femoral Canal
25.2.1 Groin Hernias
25.3 Epidemiology
25.3.1 Groin Hernias
25.3.2 Abdominal Wall Hernias
25.3.3 Diagnosis
25.3.4 Treatment
Objectives
Understand the basic anatomy associated with hernias
Gain an insight on basic epidemiologic facts
Understand the signs and symptoms and diagnostic steps for incarcerated or strangulated hernias
Know the basic approaches to various types of incarcerated and strangulated hernias
Avoid basic pitfalls associated with the diagnosis and treatment of these diseases
25.1 Surgical Anatomy
25.1.1 Abdominal Wall
Layered structure extending from the xiphoid process and the costal margins superiorly to the pubic symphysis inferiorly
Musculature:
Two recti abdominis muscles
Each runs from the xiphoid process to the pubic symphysis, and its lateral border has a convex shape, which gives rise to the linea semilunaris.
Lateral abdominal muscles
Includes three muscles from superficial to deep: the external oblique, the internal oblique, and the transversus abdominis muscles.
Medially, continue as tendinous aponeuroses, which, after forming the rectus sheath, end in the midline, where they interwine with the aponeurotic fibers of the contralateral musculature forming the linea alba.
The inferior edge of the external oblique aponeurosis gives rise to the inguinal ligament (of Poupart).
The inferiormost fibers of the internal oblique fuse with the lower fibers of the transversus abdominis muscle to form the conjoined tendon.
Deep to the lateral abdominal muscles lies the transversalis fascia, just superficial to the parietal peritoneum.
An important landmark of the anterior abdominal wall, which signifies a transition point in the layers of the rectus sheath, is the arcuate line, located midway between the umbilicus and the symphysis pubis.
The rectus sheath is divided in an anterior and a posterior portion.
Up to the level of the arcuate line:
The anterior rectus sheath is formed by the external oblique aponeurosis and the external lamina of the internal oblique aponeurosis.
The posterior rectus sheath is formed by the internal lamina of the internal oblique aponeurosis, the transversus abdominis aponeurosis, and the transversalis fascia.
Below this point:
Anterior rectus sheath contains the aponeuroses of all three lateral abdominal muscles.
The posterior rectus sheath contains only the transversalis fascia.
Blood supply
Derived from the superior artery and inferior epigastric arteries, which travel in either posterior rectus sheath and meet approximately at the level of the arcuate line.
25.1.2 Inguinal Region
Inguinal canal: cone-shaped canal, approximately 4–6 cm long, extending from the deep (internal) to the superficial (external) inguinal ring
Deep inguinal ring: opening in the transversalis fascia located approximately halfway between the anterior superior iliac spine and the pubic tubercle
Superficial inguinal ring: opening in the medial aspect of the external oblique aponeurosis, just above the pubic tubercle
Boundaries:
Anteriorly, the external oblique aponeurosis and internal oblique muscle laterally
Posteriorly, the fusion of the transversalis fascia and transversus abdominis muscle, although the latter may be absent in up to one-fourth of subjects
Superiorly, fibers of the internal oblique and transversus abdominis muscle and their conjoined tendon
Inferiorly, the inguinal ligament
Contains
Ilioinguinal nerve
The spermatic cord in men
The round ligament of the uterus in women
The iliopubic tract: band of connective tissue located deep and parallel to the inguinal ligament, extending from the anterior superior iliac spine to the superior pubic ramus, where it forms the lacunar ligament (of Gimbernat)
Separated from the inguinal ligament by the transversus abdominis and the transversalis fascia
Passes below the deep inguinal ring, forming eventually the superior border of the femoral sheath
Cooper’s ligament or pectineal ligament:
Extends from the lateral portion of the lacunar ligament
Runs laterally for about 2.5 cm along the iliopectineal line and is fused to the periosteum of the pubic tubercle
Lies posterior to the iliopubic tract and forms the posterior border of the femoral canal
Hasselbach’s triangle is bounded by:
The inguinal ligament inferiorly
The lateral border of the rectus abdominis medially
The inferior epigastric vessels superolaterally
25.1.3 Femoral Canal
Bounded by:
Iliopubic tract anteriorly
Cooper’s ligament posteriorly
Femoral vein laterally
Lacunar ligament medially
25.2 Definitions: Classification of Hernias
Definition: abnormal protrusion of intra-abdominal contents through a fascial defect in the abdominal wall
If the contents of the sac return to the abdomen spontaneously or with manual pressure when the patient is recumbent, the hernia is reducible.
If the contents of the sac cannot be returned to the abdomen, the hernia is incarcerated (incarceration does not always imply strangulation).
If the blood supply to the incarcerated hernia contents is compromised, leading to necrosis and/or perforation, the hernia is strangulated.
Special types of hernias include Richter’s, Littre’s, Amyand’s and sliding hernias.
Richter’s hernia: only part of the circumference of the bowel becomes incarcerated or strangulated in the fascial defect.
Littre’s hernia: contains Meckel’s diverticulum.
Amyand’s hernia: incarcerated inguinal hernia that contains the appendix.
Sliding hernias: a part of the wall of the hernia sac is formed by the peritoneum of an intra-abdominal viscus (typically colon or bladder).
25.2.1 Groin Hernias
Classifications:
Numerous classification systems for groin hernias exist, such as the Nyhus classification, but they are not used in the clinical setting and serve primarily for academic purposes.
Based on their location, one defines
Indirect inguinal
Sac passes through the deep inguinal ring, lateral to the epigastric vessels, and crosses the inguinal canal.
If the hernia exits into the scrotum by way of the superficial inguinal ring, it is termed complete.
Direct inguinal
Visceral protrusion through a weakness in the posterior inguinal wall.
The base of the hernia sac is the Hesselbach’s triangle, medial to the epigastric vessels.
In combined (pantaloon) hernias, direct and indirect hernias coexist.
Femoral hernias
Visceral protrusions through the femoral canal.
25.2.2 Abdominal Wall Hernias (Also Known as Ventral Hernias)
May be congenital or acquired
Acquired ventral hernias are further subdivided into incisional and nonincisional (or true ventral hernias).
Some examples of nonincisional hernias include epigastric, paraumbilical, umbilical, spigelian, and obturator hernias.
25.3 Epidemiology
25.3.1 Groin Hernias
Comprise approximately 75 % of all abdominal wall hernias.
Approximately 96 % are inguinal and 4 % are femoral.
Inguinal hernias are more common in men than in women (9:1).
Femoral hernias are more common in women (4:1).
The lifetime risk of developing a groin hernia is approximately 25 % in men and 2 % in women.
Two-thirds of inguinal hernias are indirect.Related posts:
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