Inguinal hernia

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(Redirected from
Direct inguinal hernia
)
Inguinal hernia
collagen vascular disease, connective tissue disease, previous open appendectomy[1][2][3]
Diagnostic methodBased on symptoms, medical imaging[1]
TreatmentConservative, surgery[1]
Frequency27% (males), 3% (females)[1]
Deaths59,800 (2015)[4]

An inguinal hernia or groin hernia is a

intestine is blocked. This usually produces severe pain and tenderness of the area.[1]

Risk factors for the development of a hernia include:

Deleterious mutations causing predisposition to hernias seem to have dominant inheritance (especially for men). It is unclear if inguinal hernias are associated with heavy lifting. Hernias can often be diagnosed based on signs and symptoms. Occasionally medical imaging is used to confirm the diagnosis or rule out other possible causes.[1]

Groin hernias that do not cause symptoms in males do not need to be repaired. Repair, however, is generally recommended in females due to the higher rate of

general anesthesia. Laparoscopic surgery generally has less pain following the procedure.[1][9]

In 2015 inguinal, femoral and abdominal hernias affected about 18.5 million people.[10] About 27% of males and 3% of females develop a groin hernia at some time in their life.[1] Groin hernias occur most often before the age of one and after the age of fifty.[2] Globally, inguinal, femoral and abdominal hernias resulted in 60,000 deaths in 2015 and 55,000 in 1990.[4][11]

Signs and symptoms

Frontal view of an inguinal hernia (right).

Hernias usually present as bulges in the groin area that can become more prominent when coughing, straining, or standing up. The bulge commonly disappears on lying down. Mild discomfort can develop over time. The inability to "reduce", or place the bulge back into the abdomen usually means the hernia is 'incarcerated' which requires emergency surgery.

Another frontal view of such a hernia, this time without pubic hair.

As the hernia progresses, contents of the abdominal cavity, such as the intestines, can descend into the hernia and run the risk of being pinched within the hernia, causing an

intestinal obstruction. Significant pain at the hernia site is suggestive of a more severe course, such as incarceration (the hernia cannot be reduced back into the abdomen) and subsequent ischemia and strangulation (when the hernia becomes deprived of blood supply).[12] If the blood supply of the portion of the intestine caught in the hernia is compromised, the hernia is deemed "strangulated" and gut ischemia and gangrene
can result, with potentially fatal consequences. The timing of complications is not predictable.

Pathophysiology

In males, indirect hernias follow the same route as the descending

physiological difference between patients who develop a hernia and those who do not, namely the presence of aponeurotic extensions from the transversus abdominis aponeurotic arch.[13]

Inguinal hernias mostly contain

urinary bladder, ovaries, and rarely malignant lesions.[14]

  • Illustration of an inguinal hernia.
    Illustration of an inguinal hernia.
  • Different types of inguinal hernias.
    Different types of inguinal hernias.
  • Inguinal fossae
    Inguinal fossae

Diagnosis

An incarcerated inguinal hernia as seen on cross sectional CT scan
A frontal view of an incarcerated inguinal hernia (on the patient's left side) with dilated loops of bowel above.
An inguinal hernia which contains part of the bladder. Bladder cancer also present.

There are two types of inguinal

processus vaginalis
.

In the case of the female, the opening of the

superficial inguinal ring
is smaller than that of the male. As a result, the possibility for hernias through the inguinal canal in males is much greater because they have a larger opening and therefore a much weaker wall through which the intestines may protrude.

Type Description Relationship to inferior epigastric vessels Covered by internal spermatic fascia? Usual onset
Direct inguinal hernia Enters through a weak point in the fascia of the abdominal wall (
Hesselbach triangle
)
Medial No Adult
Indirect inguinal hernia Protrudes through the inguinal ring and is ultimately the result of the
processus vaginalis failing to close after the testicle's passage
during the embryonic stage
Lateral Yes Congenital / Adult

Inguinal hernias, in turn, belong to groin hernias, which also includes femoral hernias. A femoral hernia is not via the inguinal canal, but via the femoral canal, which normally allows passage of the common femoral artery and vein from the pelvis to the leg.

In Amyand's hernia, the content of the hernial sac is the appendix.

Ultrasound image of inguinal hernia. Moving intestines in inguinal canal with respiration.

In

Littre's hernia, the content of the hernial sac contains a Meckel's diverticulum
.

Clinical classification of hernia is also important according to which hernia is classified into

  1. Reducible hernia: is one which can be pushed back into the abdomen by putting manual pressure to it.
  2. Irreducible/Incarcerated hernia: is one which cannot be pushed back into the abdomen by applying manual pressure.

Irreducible hernias are further classified into

  1. Obstructed hernia: is one in which the lumen of the herniated part of intestine is obstructed.
  2. Strangulated hernia: is one in which the blood supply of the hernia contents is cut off, thus, leading to ischemia. The lumen of the intestine may be patent or not.

Direct inguinal hernia

The direct inguinal hernia enters through a weak point in the fascia of the abdominal wall, and its sac is noted to be medial to the inferior epigastric vessels. Direct inguinal hernias may occur in males or females, but males are ten times more likely to get a direct inguinal hernia.[15]

A direct inguinal hernia protrudes through a weakened area in the

superficial inguinal ring and are unable to extend into the scrotum
.

When a patient develops a simultaneous direct and indirect hernia on the same side, it is called a pantaloon hernia or saddlebag hernia because it resembles a pair of pants with the epigastric vessels in the crotch, and the defects can be repaired separately or together. Another term for pantaloon hernia is Romberg's hernia.

Since the abdominal walls weaken with age, direct hernias tend to occur in the middle-aged and elderly. This is in contrast to indirect hernias which can occur at any age including the young, since their etiology includes a congenital component where the inguinal canal is left more patent (compared to individuals less susceptible to indirect hernias).[16][17] Additional risk factors include chronic constipation, being overweight or obese, chronic cough, family history and prior episodes of direct inguinal hernias.[15]

Indirect inguinal hernia

Ultrasound of an indirect hernia containing fat, with testicle seen at right.
T2 weighted
MRI of the same case (done for another purpose), also demonstrating fat content.
Ultrasound showing an indirect inguinal hernia[18]
Incarcerated inguinal hernia[19]

An indirect inguinal hernia results from the failure of embryonic closure of the

deep inguinal ring. In the male it can occur after the testicle
has passed through the deep inguinal ring. It is the most common cause of groin hernia. A double indirect inguinal hernia has two sacs.

In the male fetus, the

processus vaginalis. In normal development, the processus is obliterated once the testicle is completely descended. The permanent coat of peritoneum that remains around the testicle is called the tunica vaginalis. The testicle remains connected to its blood vessels and the vas deferens, which make up the spermatic cord
and descend through the inguinal canal to the scrotum.

The deep inguinal ring, which is the beginning of the inguinal canal, remains as an opening in the fascia transversalis, which forms the fascial inner wall of the spermatic cord. When the opening is larger than necessary for passage of the spermatic cord, the stage is set for an indirect inguinal hernia. The protrusion of peritoneum through the

internal inguinal ring
can be considered an incomplete obliteration of the processus.

In an indirect inguinal hernia, the protrusion passes through the deep inguinal ring and is located lateral to the inferior epigastric artery. Hence, the conjoint tendon is not weakened.

There are three main types

  • Bubonocele: in this case the hernia is limited in inguinal canal.
  • Funicular: here the processus vaginalis is closed at its lower end just above the epididymis. The content of the hernial sac can be felt separately from the testis which lies below the hernia.
  • Complete (or scrotal): here the processus vaginalis is patent throughout. The hernial sac is continuous with the tunica vaginalis of the testis. The hernia descends down to the bottom of the scrotum and it is difficult to differentiate the testis from hernia.

In the female, groin hernias are only 4% as common as in males. Indirect inguinal hernia is still the most common groin hernia for females. If a woman has an indirect inguinal hernia, her internal inguinal ring is patent, which is abnormal for females. The protrusion of peritoneum is not called "processus vaginalis" in women, as this structure is related to the migration of the testicle to the scrotum. It is simply a hernia sac. The eventual destination of the hernia contents for a woman is the

labium majus on the same side, and hernias can enlarge one labium dramatically if they are allowed to progress.[citation needed
]

Medical imaging

A physician may diagnose an inguinal hernia, as well as the type, from

medical ultrasonography is the first choice of imaging, because it can both detect the hernia and evaluate its changes with for example pressure, standing and Valsalva maneuver.[21]

When assessed by

lipomas, as both can contain only fat and extend along the inguinal canal into the scrotum.[22]

On axial

CT, lipomas originate inferior or lateral to the cord, and are located inside the cremaster muscle, while inguinal hernias lie anteromedial to the cord and are not intramuscular. Large lipomas may appear nearly indistinguishable as the fat engulfs anatomic boundaries, but they do not change position with coughing or straining.[22]

Differential diagnosis

Differential diagnosis of the symptoms of inguinal hernia mainly includes the following potential conditions:[23]

Management

Conservative

There is currently no medical recommendation about how to manage an inguinal hernia condition in adults, due to the fact that, until recently,

post-herniorrhaphy pain syndrome.[27] Elasticated pants[specify] used by athletes may also provide useful support for the smaller hernia.[citation needed
]

Surgical

Surgical incision in groin after inguinal hernia operation

Surgical correction of inguinal hernias is called a

post herniorraphy pain syndrome. Surgery is commonly performed as outpatient surgery. There are various surgical strategies which may be considered in the planning of inguinal hernia repair. These include the consideration of mesh use (e.g. synthetic or biologic), open repair, use of laparoscopy, type of anesthesia (general or local), appropriateness of bilateral repair, etc. Mesh or non mesh repairs have both benefits in different areas, but mesh repairs may reduce the rate of hernia reappearance, visceral or neurovascular injuries, length of hospital stay and time to return to activities of daily living.[28] Laparoscopy is most commonly used for non-emergency cases; however, a minimally invasive open repair may have a lower incidence of post-operative nausea and mesh associated pain. During surgery conducted under local anaesthesia, the patient will be asked to cough and strain during the procedure to help in demonstrating that the repair is without tension and sound.[29]

Frank Lamb, a black slave born near Halifax, North Carolina in 1789, affected by a major inguinal hernia since the age of 9 and whom his masters and bosses forced to perform hard labor in spite of it. He was hospitalized in 1867 and underwent a successful surgery.
(photo: United States Military Medical Archives)
The photograph is blurry as the patient was shaking too much.

Constipation after hernia repair results in strain to evacuate the bowel causing pain, and fear that the sutures may rupture. Opioid analgesia makes constipation worse. Promoting an easy bowel motion is important post-operatively.

Surgical correction is always recommended for inguinal hernias in children.[30]

Emergency surgery for incarceration and strangulation carry much higher risk than planned, "elective" procedures. However, the risk of incarceration is low, evaluated at 0.2% per year.

inguinodynia (10-12%), and this is why males with minimal symptoms are advised to watchful waiting.[31][32] However, if they experience discomfort while doing physical activities or they routinely avoid them for fear of pain, they should seek surgical evaluation.[33] For female patients, surgery is recommended even for asymptomatic patients.[34]

Epidemiology

A direct inguinal hernia is less common (~25–30% of inguinal hernias) and usually occurs in men over 40 years of age.

Men have an 8 times higher incidence of inguinal hernia than women.[35]

See also

  • Birkett hernia

References

  1. ^
    PMID 25693015. Archived from the original
    (PDF) on 18 November 2021. Retrieved 18 November 2021.
  2. ^ .
  3. .
  4. ^ .
  5. .
  6. .
  7. .
  8. .
  9. .
  10. .
  11. .
  12. .
  13. .
  14. .
  15. ^ a b "Direct Inguinal Hernia". University of Connecticut. Archived from the original on April 27, 2012. Retrieved May 6, 2012.
  16. ^ James Harmon M.D. Lecture 13. Human Gross Anatomy. University of Minnesota. September 4, 2008.
  17. ^ "Hernia: Treatment, Types, Symptoms (Pain) & Surgery".
  18. ^ "UOTW #16 - Ultrasound of the Week". Ultrasound of the Week. 2 September 2014. Retrieved 27 May 2017.
  19. ^ "UOTW #40 - Ultrasound of the Week". Ultrasound of the Week. 9 March 2015.
  20. PMID 23939566
    .
  21. .
  22. ^ .
  23. .
  24. .
  25. .
  26. .
  27. .
  28. .
  29. ^ Inguinal Hernia Archived 2007-09-27 at the Wayback Machine
  30. ^ "Inguinal Hernia". UCSF Pediatric Surgery. Archived from the original on 2020-10-26. Retrieved 2018-11-15.
  31. ^
    PMID 16418463
    .
  32. ^ Simons MP, Aufenacker TJ, Berrevoet F, Bingener J, Bisgaard T, Bittner R, et al. (2017). World guidelines for groin hernia management (PDF).
  33. ^ Brooks D. "Overview of treatment for inguinal and femoral hernia in adults". www.uptodate.com. Retrieved 2017-11-19.
  34. PMID 21299930
    .
  35. ^ "Inguinal hernia". Mayo Clinic. 2017-08-11.

External links