General Surgery & Family Medicine
Inguinal hernia
An inguinal hernia is the protrusion of an intra-abdominal structure - most often a small loop or peritoneal fat - through a defect in the posterior wall of the inguinal canal. It is the most common abdominal wall hernia, accounting for around 75 % of all adult hernias. Its prevalence is significantly higher in men (M/F ratio ≈ 9:1) due to the anatomical peculiarities of the male inguinal canal, a legacy of embryological testicular migration. A classic distinction is made between indirect hernias (congenital or acquired - involving the deep inguinal orifice, lateral to the lower epigastric vessels) and direct hernias (acquired - weakness of the posterior wall of the canal, medial to the epigastric vessels). Inguinal hernia is a benign condition in the vast majority of cases, but can be complicated by hernial strangulation - an absolute surgical emergency involving the vitality of the herniated contents and potentially the vital prognosis. Hernia repair surgery is one of the most widely performed general surgical procedures in the world, with over one million operations performed annually in the United States and around 30,000 in Quebec. Current techniques favor prosthetic (mesh) repair, with recurrence rates of less than 2-5 %, either open (Lichtenstein) or laparoscopic (TEP/TAPP).
Anatomy, classification and risk factors
- Anatomy of the inguinal canal and basis of hernia types : inguinal canal: 4-6 cm oblique duct passing through the lower abdominal wall → deep (internal) inguinal orifice: opening in the fascia transversalis → lateral to the lower epigastric vessels + superficial (external) inguinal orifice: opening in the fascia of the external oblique muscle → above and medial to the pubis → contents in men: spermatic cord (testicular artery + deferent artery + veins of the pamphiform plexus + deferent canal + genitofemoral + ilioinguinal + lymphatic nerves) → in women: round ligament of uterus → posterior wall of inguinal canal (fascia transversalis): zone of relative weakness - reinforced by conjoint tendon (false inguinal) and Hesselbach's ligament; Hesselbach's triangle: key anatomical landmark → delimited by: lateral border of rectus abdominis (medial) + inferior epigastric vessels (lateral) + inguinal ligament (inferior) → area of relative weakness corresponding to site of direct hernias; indirect hernia: crosses deep inguinal orifice → descends into inguinal canal following course of spermatic cord → may descend to scrotum → lateral to inferior epigastric vessels → most frequent type (60-70 % of inguinal hernias) → origin: persistence of vaginal process (unobliterated peritoneovaginal canal - congenital hernia in children) or acquired weakness of deep orifice in adults + direct hernia: passes directly through posterior wall of canal (Hesselbach's triangle) → medial to inferior epigastric vessels → acquired + linked to weakening of fascia transversalis (age + exertion + obesity) → less risk of strangulation than indirect hernia (wide neck)
- Classification and risk factors : Aachen (Schumpelick) or EHS (European Hernia Society) classification: primary vs. recurrent hernias + medial (direct) hernia + lateral (indirect) hernia + femoral (crural) hernia → defect rating: 1 (3 cm) → guides choice of surgical technique and type of prosthesis; Gilbert-Rutkow classification (inguinal hernias): type I to VII according to size of deep orifice and indirect or direct nature; inguinal hernia risk factors: non-modifiable: male sex (M/F ratio 9:1) + age (peak in men after age 40) + family history (genetic component - type I collagen deficiency - association with Marfan + Ehlers-Danlos syndrome) + history of contralateral hernia or recurrence + prematurity (peritoneovaginal canal not closed) + modifiable: physical activity with chronic abdominal hyperpressure (strength work + weightlifting) + chronic constipation + chronic dysuria (prostatism) + COPD + chronic cough + obesity (increased intra-abdominal pressure) + smoking (collagen degradation by MMP metalloproteinases) + previous abdominal surgery (adhesions + parietal weaknesses); epidemiology: lifetime prevalence in men: 27 % + in women: 3 % + bilateral in 20-30 % of cases → systematically look for contralateral side during workup → at inguinal ultrasound or during laparoscopic repair
- Clinical presentation and diagnosis: symptoms: intermittent inguinal swelling: appears on exertion (coughing + defecation + Valsalva) + disappears on decubitus (reducible hernia) → sensation of heaviness + discomfort or moderate pain on exertion → possible irradiation to OGE (scrotum + greater lip) → may be asymptomatic (chance discovery on clinical examination or imaging); clinical examination: patient standing + lying + coughing (increase in abdominal pressure) → palpation of inguinal region and scrotum → reducible mass → assess: size + site (inguinal canal + scrotum) + reducibility + painful nature + translumination (if cyst) → indirect hernia: descending course towards scrotum → direct hernia: non-descending medial bulge + finger-like swelling in scrotum → clinical differentiation often difficult (moderate importance as surgical technique is adapted intraoperatively); differential diagnoses to be ruled out: inguinal adenopathy (firm + non reducible + look for portal of entry + CBC + LDH) + spermatic cord cyst (translucent) + hydrocele (translucent - no cough impulse) + varicocele («bag of worms» + disappears on decubitus) + cord lipoma (fatty tissue fatty tissue + cord path) + ectopic or undescended testicle (scrotal examination - testicle absent) + femoral artery aneurysm (pulsatile) + femoral hernia (crural - under inguinal ligament) + psoas abscess (pain on hip flexion + fever) ; imaging if diagnostic doubt : inguinal and scrotal ultrasound: method of 1st intention → sensitivity 75-92 % + specificity 82-95 % for inguinal hernia → useful if hernia not palpable or diagnostic doubt + abdominopelvic CT scan: if bulky hernia + suspicion of complication + preoperative work-up of complex recurrent hernia → MRI: alternative if contraindication to CT scan (allergy to contrast + pregnancy)
Surgical treatment, complications and follow-up
| Clinical situation | Evaluation and Decision | Technique and follow-up |
|---|---|---|
| Uncomplicated inguinal hernia — surgical indications and watchful waiting Watchful waiting — Lichtenstein — laparoscopic — TEP/TAPP |
The surgical indication for inguinal hernia has evolved with data from randomized trials - active surveillance (watchful waiting) is now a validated option for some patients; Fitzgibbons «watchful waiting» randomized trial (2006 - JAMA): 720 men with asymptomatic or minimally symptomatic inguinal hernia → randomized immediate surgery vs active surveillance → results at 2 years then 7.5 years (Fitzgibbons 2013 - JAMA): no significant difference for mortality + strangulation rate in surveillance group: 0.3 %/year → very low → conclusion: active surveillance acceptable in asymptomatic men → however: 70 % of patients in the surveillance group eventually opted for surgery within 7.5 years (progressively disabling pain); UK MRC trial (O'Dwyer 2006 - BMJ): similar results → confirmation that surveillance is safe but that the majority of patients eventually require surgery; current indications for surgery (EHS Guidelines 2018 - Miserez et al.): symptomatic inguinal hernia (pain + functional discomfort) → surgery recommended + asymptomatic inguinal hernia in men in good general condition → elective surgery recommended (low risk of strangulation but better long-term quality of life) + active surveillance acceptable in: asymptomatic patient with significant surgical comorbidities + limited life expectancy + refusal of surgery + inguinal hernia in women: surgery recommended without delay (higher risk of strangulation than in men - often unrecognized associated femoral hernia) | Surgical techniques - open and laparoscopic approach: open approach - Lichtenstein technique (tension-free mesh repair): reference method in the open approach → inguinal incision + dissection of the inguinal canal + reduction of the hernia sac + reinforcement of the posterior wall with a polypropylene prosthesis attached to the inguinal ligament + conjoint tendon → can be performed under local anesthesia + sedation (advantage in patients at cardiorespiratory risk) → 5-year recurrence rate: 0.5-2 % → recommended as reference by EHS for primary unilateral hernia in men under local anesthesia + laparoscopic (minimally invasive) approach: two main techniques: TEP (totally extraperitoneal): totally extraperitoneal approach → no entry into the peritoneum → 3 trocars (umbilical + suprapubic × 2) → dissection of the space of Retzius + Bogros → placement of the prosthesis in the preperitoneal space → advantage: fewer intra-abdominal adhesions + TAPP (transabdominal preperitoneal): intraperitoneal approach → incision of the peritoneum + dissection of the preperitoneal space → placement of the prosthesis + closure of the peritoneum → advantage: better visualization + technically simpler than PET → comparative results Lichtenstein vs laparoscopic (PET/TAPP) - Cochrane meta-analysis (Miserez 2018 + McCormack 2003): short-term post-operative pain: lower laparoscopic + faster return to activity with laparoscopic + chronic post-hernioplasty pain: same or slightly lower with laparoscopic + long-term recurrence: comparable (0.5-2 % for both) + operative time: laparoscopic longer + cost: laparoscopic higher → preferred indications for laparoscopy (EHS Guidelines 2018): bilateral hernia (repair of both sides at the same time + same anesthetic benefit) + recurrent hernia after open surgery (avoids anterior scar zone) + active patients wishing rapid resumption of activity |
| Strangulated inguinal hernia - surgical emergency Strangulation — incarceration — intestinal ischemia — emergency surgery |
Hernial strangulation is the most serious and urgent complication of inguinal hernia - it constitutes an absolute surgical emergency; definitions: irreducible (incarcerated) hernia: herniated contents can no longer be reintegrated into the abdominal cavity → can be symptomatic without compromising vascularization + strangulated hernia: stricture of hernial neck → vascular compression → ischemia of herniated contents (bowel + omentum) → necrosis if untreated → absolute emergency within hours; pathophysiology of strangulation: tight hernia neck + edema of contents → venous compression → venous stasis → then arterial compression → ischemia → necrosis → perforation → peritonitis → sepsis → septic shock → death; clinical picture of strangulation: painful + non reducible + inguinal swelling without cough impulse + erythematous overlying skin (underlying necrosis) → nausea + vomiting (bowel obstruction if strangulated small loop) → fever (if necrosis + perforation) → disproportionate pain on examination + attention: Richter's hernia (partial pinching of an intestinal wall - not complete occlusion → can be misleading) → partial necrosis possible without signs of frank occlusion; strangulation risk estimation: epidemiological data: lifetime risk of strangulation: 0.3-3 %/year → cumulative risk over 5 years: 3-4 % → higher risk: indirect hernia + femoral hernia (5× higher risk than inguinal hernia) + recent hernia + small neck size + hernia in women (unrecognized femoral hernias); diagnostic pitfalls: strangulated hernia in women: often femoral hernia (not always detectable preoperatively) → strangulation rate of femoral hernias: 30-40 % vs 2-5 % for inguinal → always explore the femoral canal during hernia surgery in women | Management of hernial strangulation: in the emergency department: IV route + analgesia + CBC + ionogram + creatinine + liver panel + coagulation + group + IAR + ECG + chest X-ray + abdominopelvic CT with injection (if hemodynamically stable) → confirm diagnosis + assess vitality of contents + look for pneumoperitoneum (perforation) → NPO (nil per os) + SNG if vomiting/occlusion + prophylactic antibiotic therapy if necrosis/perforation suspected: piperacillin-tazobactam 4.5 g IV or cefazolin + metronidazole + urgent general surgery opinion; manual reduction attempt (hernia cabs): limited indications: no sign of necrosis (non-erythematous hernia + patient apyretic + <4-6h of evolution) → technique: supine + Trendelenburg + analgesia + gentle, continuous pressure towards inguinal orifice → absolute contraindications: suspicion of necrosis + fever + irritated peritoneum + more than 12h of evolution → if reduction successful → rapid elective surgery (within the next few days - no prolonged deferral as recurrence and re-incarceration are frequent); urgent strangulated hernia surgery: open route preferred in emergency (easier control + direct assessment of bowel vitality) → reduction of the hernia sac → assessment of bowel vitality: pink loop + peristalsis + mesenteric pulse → viable → reintegrate + prosthesis repair (outside contamination) + non-viable ischemic loop → bowel resection + anastomosis or stoma depending on degree of contamination → in case of frank contamination (necrosis + perforation): repair without prosthesis (simple suture Bassini or McVay type) or biological prosthesis (Permacol + Strattice) → operative mortality of strangulated hernia: 1-5 % if viable loop + 5-15 % if intestinal resection necessary (Dahlstrand 2009 - Hernia) |
| Chronic post-hernioplasty pain (CPPD) Neuralgia — prosthesis — neurectomy — neuropathic pain |
Chronic post-hernioplasty pain (CPPD) is the most frequent and long-term functional complication of hernia surgery - its prevalence and mechanism have been better understood since the 2000s; definition: persistent pain >3 months after surgery (IASP criteria - International Association for the Study of Pain) → prevalence according to studies: 10-30 % of operated patients have moderate to severe CPPD → 1-5 % have severe disabling pain (Kehlet 2006 - Lancet); mechanisms: iatrogenic neuropathy: the 3 inguinal nerves are at risk during repair: ilioinguinal nerve (sensory - inner thigh + scrotum + greater lip) + ilio-hypogastric nerve (sensory - suprapubic skin) + genital branch of genitofemoral nerve (sensory - scrotum + inner thigh + motor - cremaster) → traction + section + capture lesion in a staple or stitch → postoperative neuralgia + prosthetic mechanism: contraction and retraction of prosthesis → adhesions with nerves → chronic compression + «mesh pain» + DCPH risk factors: young age + female gender + severe preoperative pain + anxiety/catastrophization + operation under general anesthesia + open vs. laparoscopic surgery + intense postoperative acute pain (central sensitization); DCPH classification (EHS 2018): type 1 (somatic): nociceptive pain → scar + scar process + type 2 (neuropathic): burn + dysesthesias + allodynia + hyperalgesia → ilioinguinal neuralgia ++ + type 3 (mixed): somatic + neuropathic combination; assessment: DN4 (neuropathic pain questionnaire) + pain mapping + chronic pain consultation + MRI if prosthetic compression suspected. | Treatment of chronic post-hernioplasty pain: multimodal approach: tier 1 (mild to moderate pain): NSAID + paracetamol + inguinal nerve infiltration (lidocaine + corticoid) under ultrasound guidance → diagnosis + therapy + tier 2 (moderate neuropathic pain): pregabalin (Lyrica) 75-150 mg × 2/d or gabapentin (Neurontin) 300-1,200 mg/d → AMM neuropathic pain → duloxetine (Cymbalta) 60 mg/d → amitriptyline 10-75 mg/evening + tier 3 (refractory pain): multidisciplinary consultation chronic pain → neuromodulation (spinal cord stimulation - SCS) → impar ganglion block (associated pelvic pain) → revision surgery; triple neurectomy: indication: refractory disabling neuralgia after 6-12 months of conservative treatment → section of the 3 inguinal nerves (ilioinguinal + ilio-hypogastric + genital branch of the genitofemoral) → results: significant improvement in 60-80 % of patients (Amid 2004 - Arch Surg) → accompanied by permanent inguino-scrotal hypoesthesia → accepted by most patients in view of pre-existing pain + removal or repair of prosthesis: indication: DCPH secondary to prosthesis contraction/winding (mesh contraction) → removal or repositioning surgery → variable results (50-70 % improvement) → complex technique (risk of hernia recurrence + vascular lesions) → reserved for specialized hernia surgery centers (hernia clinics in Quebec: CHU de Québec + CHUM + Jewish General Hospital of Montreal); intraoperative prevention of DCPH: systematic identification + preservation of the 3 inguinal nerves + careful fixation of the prosthesis (avoid stapling above the crista iliaca) + intraoperative locoregional anesthesia (ilioinguinal / ilio-hypogastric block under ultrasound) + TAP block |
| Inguinal hernia in women, children, and obese patients Femoral hernia — pediatric hernia — round ligament — obesity |
Several populations have specific anatomical, diagnostic and therapeutic features when it comes to inguinal hernia; inguinal hernia in women: although less common, inguinal hernia in women presents a higher risk of strangulation and significant diagnostic pitfalls → special features: indirect hernia of the round ligament (borrows the deep inguinal orifice + sometimes contains an ovary or tube - Amyand or Noble de Galatoire hernia) → risk of adnexal ischemia + femoral (crural) hernia often unrecognized and confused with an inguinal hernia → passes under the inguinal ligament → into the femoral loge (femoral ring) → 3-4× more frequent in women + risk of strangulation 30-40 % vs. 2-5 % inguinal → surgical treatment without delay → systematic per-operative assessment of the femoral canal.evaluation of femoral canal in women → recommended technique: PET or TAPP (laparoscopic) → simultaneous coverage of inguinal and femoral orifices by the same prosthesis + inguinal hernia and pregnancy: if irreducible or painful hernia → surgery possible in 2nd trimester under locoregional anesthesia → if reducible + not very symptomatic → monitoring + surgery postpartum; inguinal hernia in children: almost exclusively indirect (persistence of vaginal process) + treatment: herniotomy (simple ligation-section of hernial sac without prosthesis - posterior wall is solid in children) → open inguinal approach (infant + child 2-3 years) → bilateral hernia more frequent in premature boys (30-40 %) → explore contralateral side by laparoscopy (contralateral permeable vaginal process = risk of metachronous hernia) + prematurity: surgery often after correction of gestational age → regional anesthesia (spinal anesthesia) preferable to reduce risk of post-operative apneas | Inguinal hernia and obesity - technical particularities: obesity class I-II (BMI 30-40): no contraindication to hernia surgery + laparoscopic approach (PET/TAPP) preferred → fewer wound complications (infections + hematomas) + better visualization of the preperitoneal space + severe obesity (BMI >40): increased operative risk: technical difficulties (thickness of subcutaneous fat + reduced preperitoneal space) + cardiorespiratory complications + wound infections + SAHOS → careful preoperative assessment → prior weight loss if possible (BMI target <35 before elective hernia) → feasible surgery but increased operative time → large prosthesis often required; normal operative aftermath of elective hernioplasty: outpatient surgery (1 day surgery) in 85-90 % of cases → multimodal analgesia: paracetamol + NSAID + wound infiltration (ropivacaine) ± echo-guided ilioinguinal block → resumption of walking the same evening + resumption of light activity at D2-J5 + resumption of moderate physical activity at 2-4 weeks + intense physical activity (carrying heavy loads + contact sports) at 4-6 weeks → no specific dietary restrictions → follow-up consultation at 4-6 weeks + early postoperative complications: inguinal or scrotal hematoma (5-15 % - most resolve spontaneously) + superficial wound infection (1-3 %) → antibiotic therapy + drainage if collection + deep prosthetic infection: rare (65 years with prostatism) + post-operative hydrocele + ischemic orchitis (rare - 0.5 % - vascular compression of cord) → late testicular atrophy; recurrence rate: with prosthesis (Lichtenstein + PET/TAPP): 0.5-2 % at 5 years + without prosthesis (Bassini + Shouldice - used in the context of contamination): 5-15 % at 5 years + recurrence after laparoscopic repair: open route preferred → scarring of the pre-peritoneal space makes PET revision dangerous |
ℹ️
Femoral hernia in women is not an inguinal hernia: the femoral (crural) hernia passes under the inguinal ligament and not in the inguinal canal - it is often clinically unrecognized because the swelling is less visible, located lower down and outside the pubic tubercle. Its strangulation rate of 30-40 % is much higher than that of inguinal hernia (2-5 %). Any inguinal swelling in a woman should systematically prompt a search for a femoral hernia - which has a direct influence on the choice of surgical technique.
Situations requiring urgent medical assessment
Sudden painful inguinal swelling + non-reducible + non-cough impulse + nausea + vomiting → probable strangulated hernia → surgical emergencies → emergency CT scan of the abdomen and pelvis → do not attempt reduction if there is skin erythema, fever, or symptoms >6–12h → immediate emergency surgery.
Non-reducible inguinal swelling + fever + overlying erythematous skin + disproportionate pain → necrosis of herniated contents (advanced strangulation) → absolute surgical emergency → intestinal resection likely → call 911 or go immediately to nearest emergency room.
Groin swelling in women + sharp pelvic pain + nausea → strangulated femoral hernia or incarcerated ovary/troma in an indirect inguinal hernia → surgical emergencies → emergency inguinal + pelvic ultrasound → general surgery and gynecology opinion.
Painful inguino-scrotal swelling in a boy with ipsilateral testicle not palpable in the scrotum → indirect inguinal hernia with testicle incarcerated in hernia sac → pediatric emergency → delicate reduction attempt + urgent pediatric surgical opinion.
Consult at Clinique Omicron
The doctors at Clinique Omicron evaluate inguinal hernias as part of general surgery or family medicine consultations, refer patients for elective surgery according to clinical criteria, and arrange referrals to general surgeons performing hernioplasty at one of our service locations in Quebec. For large, painful, or recurrent hernias, an inguinal ultrasound may be prescribed to confirm the diagnosis and plan management. To make an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not substitute for medical or surgical advice. Any suspected inguinal hernia must undergo a clinical examination by a healthcare professional before any therapeutic decisions are made.
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