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Inguinal hernia

Inguinal hernia is a bulge of the peritoneum through a congenital or acquired defect in the muscular and fascial structures of the abdominal wall ( Conze et al. 2001 )

A hernia is described as a protrusion of a sac of peritonium , often containing intestine or other
 abdominal contents from its proper cavity through a weakness in the abdominal wall.

Background –A hernia has three parts – the sac , the coverings of the sac and the contents Abdominal wall hernias only occur in certain areas where aponeurosis and fascia are devoid of the protecting support of the striated muscle The inguinal canal starts at the internal inguinal ring and ends at the superficial ring , it has the spermatic cord in men and the round ligament in women Groin hernias are one of the commonest reason for which primary care physicians refer patients for surgical management Femoral hernias have the highest rate of strangulation 15% to 20 % Etiology of inguinal hernia is considered mult-factorial with factors as
○ increased intra-abddominal pressure
○ changes in connective tissue Repair of an inguinal hernia is one of the most commonly performed surgical procedure worldwide

How common –Inguinal hernia is the most common abdominal wall hernia with rates varying between 0.6 % to 25.2 % among males within different age groups and populations Most patients ( up to 50 % ) are unaware that they have an inguinal hernia They happen more often in men Inguinal hernias account for 75 % of the abdominal wall hernias with a life time risk of 27 % in males and 3 % in females About 96 % of groin hernia are inguinal and about 4 % are femoral Hernias are more common in whites Inguinal hernia repair constitutes the bulk ( 95 % ) of hernia repairs carried out in the UK B/L in 20 % of cases More common on right ( 2 : 1 ) ratio
probably due to later descent of the right testicle and the associated patent processus vaginalis

Risk factors –increased abdominal pressure male gender incidence increases with age pre-existing weakness of abdominal muscles collagen metabolism heavy lifting of weights low body mass index chronic constipation inheritance – inguinal hernias are hereditary ( a male subject who has a positive family h/o hernia is 8 times more likely to develop an inguinal hernia ) among women – taller height, chronic cough , umbilical hernia , older age and rural residence rare connective tissue diseases as Ehler-Danlos syndrome Prostate – literature mentions prostate related conditions as prostatectomy or benign prostatic hypertrophy to be among the risk factors varicose veins haemorrhoids smoking ( not proven )

Classified as direct or indirect , congenital or acquired , primary or recurrent , lateral and medial
Several classifications have been tried ( starting from Casten 1967 ) reflecting the developments in hernia surgery
 Most classifications take into account the size of hernia and the status of the posterior wall & or the internal ring to describe the hernia European Hernia Society – has proposed a classification which uses both the anatomical location and size of hernia as seen intra-operatively No classification has been accorded universal acceptance among the surgical fraternity.

History –When did the patient notice the swelling / mass / pain first What makes it worse /
○ standing
○ coughing , sneezing
○ lifting heavy objects What happens when the patient lies down- does it disappear Can the patient reduce the swelling – push it back with hand – is it getting difficult to push back ?
most patients would manage to push back initially which becomes more difficult as the hernia becomes bigger H/O previous hernia repair Hernia may be asymptomatic Severe pain is generally not common and should raise suspicion of incarceration


Examination-A bulge in the area on either side of the pubic bone There may be burning , gurgling or aching sensation at the bulge pain or discomfort in the groin heavy dragging sensation in the groin which may worsen toward the end of the day and after prolonged activity examine with patient standing examine the groin and also note for any scrotal masses abdominal bulge may disappear when the patient is in prone position feel for the bulge when the patient coughs or strains ( Valsalva ) try and observe if the bulge noted is above ( inguinal hernia ) or below 
( femoral hernia ) the inguinal ligament crease nature of swelling ? soft , tender , pulsatile , reducible examine both sides significant pain , non-reducible mass and possibly overlying skin changes as erythema and warmth may suggest incarceration identifying hernia can be difficult in obese subjects large indirect hernia may extend all the way to scrotum – giving the appearance of a hydrocele diagnosing hernia is more challenging in women – it often goes undiagnosed and diagnostic laparoscopy is the most effective tool to establish the condition diagnosis can usually be established relatively easily based on physical examination

Imaging-RCS / British hernia society advice’s against imaging in primary care. Imaging in secondary care is recommended if there is diagnostic uncertainty or to exclude other pathology ( dynamic US is first line investigation ) You may consider imaging in certain circumstances as
○ suspected femoral hernia in an obese women / men
○ suspected sports hernia
○ recurrent hernia or possible hydrocele
○ uncertain diagnosis
○ surgical complications particularly chronic pain Other diagnostic modalities include
○ CT
○ MRI with or without a Valsalva manoeurve
○ herniography

Due to clinical 
inaccuracy the 
 identification if the hernia
 as direct or indirect does not
 form a good factor on which a decision whether to make a
 referral for elective repair
 should be based

Groin lumps differential diagnosis –undescended testis lymphadenopathy femoral hernia iliac or femoral aneurysm
( palpable mass ) psoas abscess saphena varux hydrocele varicocele encysted hydrocele of the spermatic cord lipoma of the spermatic cord and round ligament spermatocele lymphoma soft tissue tumour incisional hernia.

Does the patient need immediate 
surgical attention 
admission ? Hernia is become incarcerated / non-reducible
 ie the contents of the hernia sac cannot be returned to the abdominal cavity or strangulation


Strangulation
 hernia contents blood supply is compromised Irreducible hernia
( ie no expansile cough impulse ) Tender and red Pain initially over hernia is followed by generalised abdominal pain colicky in nature Systemic signs- nausea and vomiting

Obstruction Colicky abdominal pain Tenderness over hernia site Abdominal distension and vomiting Onset ↑ gradual than in strangulated hernia Obstruction can culminate in strangulation

It is important in primary care to distinguish correctly between a femoral and inguinal hernia as the femoral hernias are more likely to undergo strangulation.
 Femoral hernias are less common than inguinal hernia They happen more often in females with a female to male ratio of 10 : 1 Both hernias happen more often on the right side Typically a bulge below the inguinal ligament is consistent with a femoral hernia Surgical treatment is the only cure Suspected femoral hernia cases should be referred urgently Success rate of surgical repair is excellent.

Refer all patients with an overt or suspected primary or recurrent inguinal or femoral hernias to the surgeons Do not refer if the hernia is minimally symptomatic and the patient has significant co morbidity ( ASA 4 – a classification of risk used by anesthetists ) and the patient does not wish to undergo a surgical repair following a discussion in which you give appropriate information Irreducible and partially reducible inguinal hernias and all groin hernia in women – refer urgently Children < 18 with inguinal hernia- refer to a paediatric surgeon Conservative management is not considered prudent – outcomes are worse and it is not cost effective While the literature also reports that conservative management of asymptomatic inguinal hernia is safe but most patients would develop symptom over time and eventually need surgical intervention.

Inguinal hernia repair –Inguinal hernia repair is the one of the most common surgeries worldwide performed in more than 20 million people annually Choosing the the right technique for the hernia repair is a matter of hot debate among surgeons Mesh repair is generally recommended first choice either by an open or laparoscopic technique A Danish study has shown that the age distribution of inguinal hernia repair is bimodal – peaking at early childhood and old age Most inguinal hernias are almost always symptomatic and surgery is the only cure Surgical treatment is successful in most cases Recurrence rate after inguinal hernia repair is 3-8 % Chronic pain – after about 5 years a small proportion ( between 2 % to 3.5 % ) report moderate to severe chronic pain
laparoscopic techniques results in less chronic pain compared to open repair Other long term complications include neuralgia and IH recurrence

References

  1. Lau H, Fang C, Yuen WK, Patil NG. Risk factors for inguinal hernia in adult males: a case-control study. Surgery. 2007;141(2):262‐266. doi:10.1016/j.surg.2006.04.014 ( Abstract )
  2. Öberg, Stina et al. “Etiology of Inguinal Hernias: A Comprehensive Review.” Frontiers in surgery vol. 4 52. 22 Sep. 2017, doi:10.3389/fsurg.2017.00052 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5614933/
  3. Jensen K.K., Henriksen N.A., Jorgensen L.N. (2017) Inguinal Hernia Epidemiology. In: Hope W., Cobb W., Adrales G. (eds) Textbook of Hernia. Springer, Cham ( Abstract )
  4. Burcharth J, Pedersen M, Bisgaard T, Pedersen C, Rosenberg J (2013) Nationwide Prevalence of Groin Hernia Repair. PLoS ONE 8(1): e54367. https://doi.org/10.1371/journal.pone.0054367 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0054367
  5. McIntosh A, Hutchinson A, Roberts A, Withers H. Evidence-based management of groin hernia in primary care–a systematic review. Fam Pract. 2000;17(5):442‐447. doi:10.1093/fampra/17.5.442 ( Abstract ) https://pubmed.ncbi.nlm.nih.gov/11021907/
  6. Simons, M.P., Smietanski, M., Bonjer, H.J. et al. International guidelines for groin hernia management. Hernia 22, 1–165 (2018). https://doi.org/10.1007/s10029-017-1668-x
  7. LeBlanc KE, LeBlanc LL, LeBlanc KA. Inguinal hernias: diagnosis and management. Am Fam Physician. 2013;87(12):844‐848. https://pubmed.ncbi.nlm.nih.gov/23939566/?dopt=Abstract
  8. Inguinal Hernia. A Review Onuigbo WIB*1 and Njeze GE2 Volume 1 | Issue 2 Journal of Surgery and Operative Care ISSN: 2455-7617 www.annexpublishers.co/articles/JSOC/1202-Inguinal-Hernia-A-Review.pdf
  9. Schumpelick V., Treutner KH. (2001) Classification of Inguinal Hernias. In: Bendavid R., Abrahamson J., Arregui M.E., Flament J.B., Phillips E.H. (eds) Abdominal Wall Hernias. Springer, New York, NY
  10. Tumtavitikul, Sathien. “Highlights from the International Guidelines for Groin Hernia Management.” Annals of Laparoscopic and Endoscopic Surgery [Online], 2.11 (2017): n. pag. Web. 31 May. 2020 http://ales.amegroups.com/article/view/4219/5063
  11. Öberg, Stina et al. “Etiology of Inguinal Hernias: A Comprehensive Review.” Frontiers in surgery vol. 4 52. 22 Sep. 2017, doi:10.3389/fsurg.2017.00052
  12. Daoud I.M., Dunn K. (2016) Groin Pain Etiology: The Inguinal Hernia, the Occult Inguinal Hernia, and the Lipoma. In: Jacob B., Chen D., Ramshaw B., Towfigh S. (eds) The SAGES Manual of Groin Pain. Springer, Cham ( Abstract )
  13. Amerson JR. Inguinal Canal and Hernia Examination. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 96. Available from: https://www.ncbi.nlm.nih.gov/books/NBK423/
  14. Inguinal hernia Differential Diagnosis via https://online.epocrates.com/diseases/72335/Inguinal-hernia/Differential-Diagnosis
  15. Abdominal wall and groin masses ACS/ ASE Medical Student Core Curriculum American College of Surgeons Division of Education Page 1 of 13 Blended Surgical Education and Training for Life® https://www.facs.org/-/media/files/education/core-curriculum/abdominal_wall_groin.ashx
  16. Goethals A, Adams CT. Femoral Hernia. [Updated 2019 Dec 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535449/
  17. Mizrahi H, Parker MC. Management of Asymptomatic Inguinal Hernia: A Systematic Review of the Evidence. Arch Surg. 2012;147(3):277–281. doi:10.1001/archsurg.2011.914
  18. Simons, M P et al. “European Hernia Society guidelines on the treatment of inguinal hernia in adult patients.” Hernia : the journal of hernias and abdominal wall surgery vol. 13,4 (2009): 343-403. doi:10.1007/s10029-009-0529-7

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